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Sample records for basic helix-loop-helix protein-mediated

  1. The basic helix-loop-helix transcription factor, Mist1, induces maturation of mouse fetal hepatoblasts

    PubMed Central

    Chikada, Hiromi; Ito, Keiichi; Yanagida, Ayaka; Nakauchi, Hiromitsu; Kamiya, Akihide

    2015-01-01

    Hepatic stem/progenitor cells, hepatoblasts, have a high proliferative ability and can differentiate into mature hepatocytes and cholangiocytes. Therefore, these cells are considered to be useful for regenerative medicine and drug screening for liver diseases. However, it is problem that in vitro maturation of hepatoblasts is insufficient in the present culture system. In this study, a novel regulator to induce hepatic differentiation was identified and the molecular function of this factor was examined in embryonic day 13 hepatoblast culture with maturation factor, oncostatin M and extracellular matrices. Overexpression of the basic helix-loop-helix type transcription factor, Mist1, induced expression of mature hepatocytic markers such as carbamoyl-phosphate synthetase1 and several cytochrome P450 (CYP) genes in this culture system. In contrast, Mist1 suppressed expression of cholangiocytic markers such as Sox9, Sox17, Ck19, and Grhl2. CYP3A metabolic activity was significantly induced by Mist1 in this hepatoblast culture. In addition, Mist1 induced liver-enriched transcription factors, CCAAT/enhancer-binding protein ? and Hepatocyte nuclear factor 1?, which are known to be involved in liver functions. These results suggest that Mist1 partially induces mature hepatocytic expression and function accompanied by the down-regulation of cholangiocytic markers. PMID:26456005

  2. The basic helix-loop-helix transcription factor, Mist1, induces maturation of mouse fetal hepatoblasts.

    PubMed

    Chikada, Hiromi; Ito, Keiichi; Yanagida, Ayaka; Nakauchi, Hiromitsu; Kamiya, Akihide

    2015-01-01

    Hepatic stem/progenitor cells, hepatoblasts, have a high proliferative ability and can differentiate into mature hepatocytes and cholangiocytes. Therefore, these cells are considered to be useful for regenerative medicine and drug screening for liver diseases. However, it is problem that in vitro maturation of hepatoblasts is insufficient in the present culture system. In this study, a novel regulator to induce hepatic differentiation was identified and the molecular function of this factor was examined in embryonic day 13 hepatoblast culture with maturation factor, oncostatin M and extracellular matrices. Overexpression of the basic helix-loop-helix type transcription factor, Mist1, induced expression of mature hepatocytic markers such as carbamoyl-phosphate synthetase1 and several cytochrome P450 (CYP) genes in this culture system. In contrast, Mist1 suppressed expression of cholangiocytic markers such as Sox9, Sox17, Ck19, and Grhl2. CYP3A metabolic activity was significantly induced by Mist1 in this hepatoblast culture. In addition, Mist1 induced liver-enriched transcription factors, CCAAT/enhancer-binding protein ? and Hepatocyte nuclear factor 1?, which are known to be involved in liver functions. These results suggest that Mist1 partially induces mature hepatocytic expression and function accompanied by the down-regulation of cholangiocytic markers. PMID:26456005

  3. Structural basis for PAS domain heterodimerization in the basic helix--loop--helix-PAS transcription factor hypoxia-inducible factor.

    PubMed

    Erbel, Paul J A; Card, Paul B; Karakuzu, Ozgur; Bruick, Richard K; Gardner, Kevin H

    2003-12-23

    Biological responses to oxygen availability play important roles in development, physiological homeostasis, and many disease processes. In mammalian cells, this adaptation is mediated in part by a conserved pathway centered on the hypoxia-inducible factor (HIF). HIF is a heterodimeric protein complex composed of two members of the basic helix-loop-helix Per-ARNT-Sim (PAS) (ARNT, aryl hydrocarbon receptor nuclear translocator) domain family of transcriptional activators, HIFalpha and ARNT. Although this complex involves protein-protein interactions mediated by basic helix-loop-helix and PAS domains in both proteins, the role played by the PAS domains is poorly understood. To address this issue, we have studied the structure and interactions of the C-terminal PAS domain of human HIF-2alpha by NMR spectroscopy. We demonstrate that HIF-2alpha PAS-B binds the analogous ARNT domain in vitro, showing that residues involved in this interaction are located on the solvent-exposed side of the HIF-2alpha central beta-sheet. Mutating residues at this surface not only disrupts the interaction between isolated PAS domains in vitro but also interferes with the ability of full-length HIF to respond to hypoxia in living cells. Extending our findings to other PAS domains, we find that this beta-sheet interface is widely used for both intra- and intermolecular interactions, suggesting a basis of specificity and regulation of many types of PAS-containing signaling proteins. PMID:14668441

  4. A novel basic helix-loop-helix protein is expressed in muscle attachment sites of the Drosophila epidermis.

    PubMed Central

    Armand, P; Knapp, A C; Hirsch, A J; Wieschaus, E F; Cole, M D

    1994-01-01

    We have found that a novel basic helix-loop-helix (bHLH) protein is expressed almost exclusively in the epidermal attachments sites for the somatic muscles of Drosophila melanogaster. A Drosophila cDNA library was screened with radioactively labeled E12 protein, which can dimerize with many HLH proteins. One clone that emerged from this screen encoded a previously unknown protein of 360 amino acids, named delilah, that contains both basic and HLH domains, similar to a group of cellular transcription factors implicated in cell type determination. Delilah protein formed heterodimers with E12 that bind to the muscle creatine kinase promoter. In situ hybridization with the delilah cDNA localized the expression of the gene to a subset of cells in the epidermis which form a distinct pattern involving both the segmental boundaries and intrasegmental clusters. This pattern was coincident with the known sites of attachment of the somatic muscles to tendon cells in the epidermis. delilah expression persists in snail mutant embryos which lack mesoderm, indicating that expression of the gene was not induced by attachment of the underlying muscles. The similarity of this gene to other bHLH genes suggests that it plays an important role in the differentiation of epidermal cells into muscle attachment sites. Images PMID:8196652

  5. Genome-wide features of neuroendocrine regulation in Drosophila by the basic helix-loop-helix transcription factor DIMMED

    PubMed Central

    Hadži?, Tarik; Park, Dongkook; Abruzzi, Katharine C.; Yang, Lin; Trigg, Jennifer S.; Rohs, Remo; Rosbash, Michael; Taghert, Paul H.

    2015-01-01

    Neuroendocrine (NE) cells use large dense core vesicles (LDCVs) to traffic, process, store and secrete neuropeptide hormones through the regulated secretory pathway. The dimmed (DIMM) basic helix-loop-helix transcription factor of Drosophila controls the level of regulated secretory activity in NE cells. To pursue its mechanisms, we have performed two independent genome-wide analyses of DIMM's activities: (i) in vivo chromatin immunoprecipitation (ChIP) to define genomic sites of DIMM occupancy and (ii) deep sequencing of purified DIMM neurons to characterize their transcriptional profile. By this combined approach, we showed that DIMM binds to conserved E-boxes in enhancers of 212 genes whose expression is enriched in DIMM-expressing NE cells. DIMM binds preferentially to certain E-boxes within first introns of specific gene isoforms. Statistical machine learning revealed that flanking regions of putative DIMM binding sites contribute to its DNA binding specificity. DIMM's transcriptional repertoire features at least 20 LDCV constituents. In addition, DIMM notably targets the pro-secretory transcription factor, creb-A, but significantly, DIMM does not target any neuropeptide genes. DIMM therefore prescribes the scale of secretory activity in NE neurons, by a systematic control of both proximal and distal points in the regulated secretory pathway. PMID:25634895

  6. anthocyanin1 of Petunia Encodes a Basic Helix-Loop-Helix Protein That Directly Activates Transcription of Structural Anthocyanin Genes

    PubMed Central

    Spelt, Cornelis; Quattrocchio, Francesca; Mol, Joseph N. M.; Koes, Ronald

    2000-01-01

    The petunia loci anthocyanin1 (an1), an2, an4, and an11 are required for the transcription of anthocyanin biosynthetic genes in floral organs. The an2 and an11 loci were recently cloned and shown to encode a MYB-domain transcriptional activator and a cytosolic WD40 protein, respectively. Here, we report the isolation of an1 by transposon tagging. an1 encodes a new member of the basic helix-loop-helix family of transcription factors that is functionally and evolutionarily distinct from JAF13, the apparent petunia ortholog of maize RED1 and snapdragon DELILA. We provide genetic evidence that the transcription factors encoded by an1, an2, and an4 operate in an unexpectedly complex regulatory hierarchy. In leaves, ectopic expression of AN2 induces an1 expression, whereas in anthers, an1 expression depends on an4, encoding (or controlling) a MYB protein that is paralogous to AN2. Experiments with transgenic plants expressing a post-translationally controlled AN1–GLUCOCORTICOID RECEPTOR fusion protein indicated that independent of protein synthesis, AN1 directly activates the expression of the dfrA gene encoding the enzyme dihydroflavonol 4-reductase and of Pmyb27 encoding a MYB-domain protein of unknown function. PMID:11006336

  7. Genome-wide identification and analysis of basic helix-loop-helix domains in dog, Canis lupus familiaris.

    PubMed

    Wang, Xu-Hua; Wang, Yong; Liu, A-Ke; Liu, Xiao-Ting; Zhou, Yang; Yao, Qin; Chen, Ke-Ping

    2015-04-01

    The basic helix-loop-helix (bHLH) domain is a highly conserved amino acid motif that defines a group of DNA-binding transcription factors. bHLH proteins play essential regulatory roles in a variety of biological processes in animal, plant, and fungus. The domestic dog, Canis lupus familiaris, is a good model organism for genetic, physiological, and behavioral studies. In this study, we identified 115 putative bHLH genes in the dog genome. Based on a phylogenetic analysis, 51, 26, 14, 4, 12, and 4 dog bHLH genes were assigned to six separate groups (A-F); four bHLH genes were categorized as ''orphans''. Within-group evolutionary relationships inferred from the phylogenetic analysis were consistent with positional conservation, other conserved domains flanking the bHLH motif, and highly conserved intron/exon patterns in other vertebrates. Our analytical results confirmed the GenBank annotations of 89 dog bHLH proteins and provided information that could be used to update the annotations of the remaining 26 dog bHLH proteins. These data will provide good references for further studies on the structures and regulatory functions of bHLH proteins in the growth and development of dogs, which may help in understanding the mechanisms that underlie the physical and behavioral differences between dogs and wolves. PMID:25403511

  8. GLABRA2 Directly Suppresses Basic Helix-Loop-Helix Transcription Factor Genes with Diverse Functions in Root Hair Development

    PubMed Central

    Lin, Qing; Ohashi, Yohei; Kato, Mariko; Tsuge, Tomohiko; Gu, Hongya; Qu, Li-Jia; Aoyama, Takashi

    2015-01-01

    The Arabidopsis thaliana GLABRA2 (GL2) gene encodes a transcription factor involved in the cell differentiation of various epidermal tissues. During root hair pattern formation, GL2 suppresses root hair development in non-hair cells, acting as a node between the gene regulatory networks for cell fate determination and cell differentiation. Despite the importance of GL2 function, its molecular basis remains obscure because the GL2 target genes leading to the network for cell differentiation are unknown. We identified five basic helix-loop-helix (bHLH) transcription factor genes—ROOT HAIR DEFECTIVE6 (RHD6), RHD6-LIKE1 (RSL1), RSL2, LjRHL1-LIKE1 (LRL1), and LRL2—as GL2 direct targets using transcriptional and post-translational induction systems. Chromatin immunoprecipitation analysis confirmed GL2 binding to upstream regions of these genes in planta. Reporter gene analyses showed that these genes are expressed in various stages of root hair development and are suppressed by GL2 in non-hair cells. GL2 promoter-driven green fluorescent protein fusions of LRL1 and LRL2, but not those of the other bHLH proteins, conferred root hair development on non-hair cells. These results indicate that GL2 directly suppresses bHLH genes with diverse functions in root hair development. PMID:26486447

  9. Target genes for OBP3, a Dof transcription factor, include novel basic helix-loop-helix domain proteins inducible by

    E-print Network

    Lin, Chentao

    proteins inducible by salicylic acid Hong-Gu Kang1,y,z , Rhonda C. Foley2,z , Luis OnÄ ate-SaÂnchez2 contributed equally to the paper. Summary Overexpression of a salicylic-acid (SA)-inducible Arabidopsis DNA helix-loop-helix, salicylic acid, jasmonic acid, AtDof3.6. Introduction Although there is considerable

  10. ZmZHOUPI, an endosperm-specific basic helix-loop-helix transcription factor involved in maize seed development.

    PubMed

    Grimault, Aurélie; Gendrot, Ghislaine; Chamot, Sophy; Widiez, Thomas; Rabillé, Hervé; Gérentes, Marie-France; Creff, Audrey; Thévenin, Johanne; Dubreucq, Bertrand; Ingram, Gwyneth C; Rogowsky, Peter M; Depège-Fargeix, Nathalie

    2015-11-01

    In angiosperm seeds the embryo is embedded within the endosperm, which is in turn enveloped by the seed coat, making inter-compartmental communication essential for coordinated seed growth. In this context the basic helix-loop-helix domain transcription factor AtZHOUPI (AtZOU) fulfils a key role in both the lysis of the transient endosperm and in embryo cuticle formation in Arabidopsis thaliana. In maize (Zea mays), a cereal with a persistent endosperm, a single gene, ZmZOU, falls into the same phylogenetic clade as AtZOU. Its expression is limited to the endosperm where it peaks during the filling stage. In ZmZOU-RNA interference knock-down lines embryo size is slightly reduced and the embryonic suspensor and the adjacent embryo surrounding region show retarded breakdown. Ectopic expression of ZmZOU reduces stomatal number, possibly due to inappropriate protein interactions. ZmZOU forms functional heterodimers with AtICE/AtSCREAM and the closely related maize proteins ZmICEb and ZmICEc, but its interaction is more efficient with the ZmICEa protein, which shows sequence divergence and only has close homologues in other monocotyledonous species. Consistent with the observation that these complexes can trans-activate target gene promoters from Arabidopsis, ZmZOU partially complements the Atzou-4 mutant. However, structural, trans-activation and gene expression data support the hypothesis that ZmZOU and ZmICEa may have coevolved to form a functional complex unique to monocot seeds. This divergence may explain the reduced functionality of ZmZOU in Arabidopsis, and reflect functional specificities which are unique to the monocotyledon lineage. PMID:26361885

  11. The Basic/Helix-Loop-Helix Protein Family in Gossypium: Reference Genes and Their Evolution during Tetraploidization

    PubMed Central

    Yan, Qian; Liu, Hou-Sheng; Yao, Dan; Li, Xin; Chen, Han; Dou, Yang; Wang, Yi; Pei, Yan; Xiao, Yue-Hua

    2015-01-01

    Basic/helix-loop-helix (bHLH) proteins comprise one of the largest transcription factor families and play important roles in diverse cellular and molecular processes. Comprehensive analyses of the composition and evolution of the bHLH family in cotton are essential to elucidate their functions and the molecular basis of cotton development. By searching bHLH homologous genes in sequenced diploid cotton genomes (Gossypium raimondii and G. arboreum), a set of cotton bHLH reference genes containing 289 paralogs were identified and named as GobHLH001-289. Based on their phylogenetic relationships, these cotton bHLH proteins were clustered into 27 subfamilies. Compared to those in Arabidopsis and cacao, cotton bHLH proteins generally increased in number, but unevenly in different subfamilies. To further uncover evolutionary changes of bHLH genes during tetraploidization of cotton, all genes of S5a and S5b subfamilies in upland cotton and its diploid progenitors were cloned and compared, and their transcript profiles were determined in upland cotton. A total of 10 genes of S5a and S5b subfamilies (doubled from A- and D-genome progenitors) maintained in tetraploid cottons. The major sequence changes in upland cotton included a 15-bp in-frame deletion in GhbHLH130D and a long terminal repeat retrotransposon inserted in GhbHLH062A, which eliminated GhbHLH062A expression in various tissues. The S5a and S5b bHLH genes of A and D genomes (except GobHLH062) showed similar transcription patterns in various tissues including roots, stems, leaves, petals, ovules, and fibers, while the A- and D-genome genes of GobHLH110 and GobHLH130 displayed clearly different transcript profiles during fiber development. In total, this study represented a genome-wide analysis of cotton bHLH family, and revealed significant changes in sequence and expression of these genes in tetraploid cottons, which paved the way for further functional analyses of bHLH genes in the cotton genus. PMID:25992947

  12. Iron-Binding E3 Ligase Mediates Iron Response in Plants by Targeting Basic Helix-Loop-Helix Transcription Factors1[OPEN

    PubMed Central

    Selote, Devarshi; Samira, Rozalynne; Matthiadis, Anna; Gillikin, Jeffrey W.; Long, Terri A.

    2015-01-01

    Iron uptake and metabolism are tightly regulated in both plants and animals. In Arabidopsis (Arabidopsis thaliana), BRUTUS (BTS), which contains three hemerythrin (HHE) domains and a Really Interesting New Gene (RING) domain, interacts with basic helix-loop-helix transcription factors that are capable of forming heterodimers with POPEYE (PYE), a positive regulator of the iron deficiency response. BTS has been shown to have E3 ligase capacity and to play a role in root growth, rhizosphere acidification, and iron reductase activity in response to iron deprivation. To further characterize the function of this protein, we examined the expression pattern of recombinant ProBTS::?-GLUCURONIDASE and found that it is expressed in developing embryos and other reproductive tissues, corresponding with its apparent role in reproductive growth and development. Our findings also indicate that the interactions between BTS and PYE-like (PYEL) basic helix-loop-helix transcription factors occur within the nucleus and are dependent on the presence of the RING domain. We provide evidence that BTS facilitates 26S proteasome-mediated degradation of PYEL proteins in the absence of iron. We also determined that, upon binding iron at the HHE domains, BTS is destabilized and that this destabilization relies on specific residues within the HHE domains. This study reveals an important and unique mechanism for plant iron homeostasis whereby an E3 ubiquitin ligase may posttranslationally control components of the transcriptional regulatory network involved in the iron deficiency response. PMID:25452667

  13. Classification and evolutionary analysis of the basic helix-loop-helix gene family in the green anole lizard, Anolis carolinensis.

    PubMed

    Liu, Ake; Wang, Yong; Zhang, Debao; Wang, Xuhua; Song, Huifang; Dang, Chunwang; Yao, Qin; Chen, Keping

    2013-08-01

    Helix-loop-helix (bHLH) proteins play essential regulatory roles in a variety of biological processes. These highly conserved proteins form a large transcription factor superfamily, and are commonly identified in large numbers within animal, plant, and fungal genomes. The bHLH domain has been well studied in many animal species, but has not yet been characterized in non-avian reptiles. In this study, we identified 102 putative bHLH genes in the genome of the green anole lizard, Anolis carolinensis. Based on phylogenetic analysis, these genes were classified into 43 families, with 43, 24, 16, 3, 10, and 3 members assigned into groups A, B, C, D, E, and F, respectively, and 3 members categorized as "orphans". Within-group evolutionary relationships inferred from the phylogenetic analysis were consistent with highly conserved patterns observed for introns and additional domains. Results from phylogenetic analysis of the H/E(spl) family suggest that genome and tandem gene duplications have contributed to this family's expansion. Our classification and evolutionary analysis has provided insights into the evolutionary diversification of animal bHLH genes, and should aid future studies on bHLH protein regulation of key growth and developmental processes. PMID:23756994

  14. Dynamic Antagonism between Phytochromes and PIF Family Basic Helix-Loop-Helix Factors Induces Selective Reciprocal Responses to Light and Shade in a Rapidly Responsive Transcriptional Network in Arabidopsis

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Plants respond to shade-modulated light signals via phytochrome (phy)-induced adaptive changes, termed shade avoidance. To examine the roles of Phytochrome-Interacting basic helix-loop-helix Factors, PIF1, 3, 4, and 5, in relaying such signals to the transcriptional network, we compared the shade-re...

  15. Genomic organization and chromosomal localization of the gene TCF15 encoding the early mesodermal basic helix-loop-helix factor bHLH-EC2

    SciTech Connect

    Hidai, H.; Quertermous, E.E.; Quertermous, T.

    1995-12-10

    bHLH-EC2 is a recently characterized member of a growing family of basic helix-loop-helix transcription factors. This family includes bHLH factors such as twist, which appear to be primarily involved in early mesodermal differentiation, and bHLH factors such as TAL-1, which have been characterized through their association with chromosomal breakpoints associated with T-cell leukemias. To provide for studies aimed at understanding the genetic regulation of bHLH-EC2, we have characterized the organization of this gene and conducted preliminary studies of the transcriptional activity of the upstream promoter region. The mouse bHLH-EC2 gene was found to consist of two exons separated by a 5-kb intron, an organization pattern similar to the mouse twist gene. The transcription initiation site was identified by RNase protection assay and primer extension analysis. Linked promoter-reporter gene transfection experiments in cultured cells indicated that while the identified upstream sequence can function to promote transcription, it does not function in a cell-specific fashion. To investigate the possible association of bHLH-EC2 with hematological malignancy, the chromosomal location of this gene in the human was mapped by fluorescence in situ hybridization and assigned to chromosome band 20p13. 16 refs., 3 figs.

  16. Arabidopsis Basic Helix-Loop-Helix Transcription Factors MYC2, MYC3, and MYC4 Regulate Glucosinolate Biosynthesis, Insect Performance, and Feeding Behavior[W][OPEN

    PubMed Central

    Schweizer, Fabian; Fernández-Calvo, Patricia; Zander, Mark; Diez-Diaz, Monica; Fonseca, Sandra; Glauser, Gaétan; Lewsey, Mathew G.; Ecker, Joseph R.; Solano, Roberto; Reymond, Philippe

    2013-01-01

    Arabidopsis thaliana plants fend off insect attack by constitutive and inducible production of toxic metabolites, such as glucosinolates (GSs). A triple mutant lacking MYC2, MYC3, and MYC4, three basic helix-loop-helix transcription factors that are known to additively control jasmonate-related defense responses, was shown to have a highly reduced expression of GS biosynthesis genes. The myc2 myc3 myc4 (myc234) triple mutant was almost completely devoid of GS and was extremely susceptible to the generalist herbivore Spodoptera littoralis. On the contrary, the specialist Pieris brassicae was unaffected by the presence of GS and preferred to feed on wild-type plants. In addition, lack of GS in myc234 drastically modified S. littoralis feeding behavior. Surprisingly, the expression of MYB factors known to regulate GS biosynthesis genes was not altered in myc234, suggesting that MYC2/MYC3/MYC4 are necessary for direct transcriptional activation of GS biosynthesis genes. To support this, chromatin immunoprecipitation analysis showed that MYC2 binds directly to the promoter of several GS biosynthesis genes in vivo. Furthermore, yeast two-hybrid and pull-down experiments indicated that MYC2/MYC3/MYC4 interact directly with GS-related MYBs. This specific MYC–MYB interaction plays a crucial role in the regulation of defense secondary metabolite production and underlines the importance of GS in shaping plant interactions with adapted and nonadapted herbivores. PMID:23943862

  17. The Basic Helix-Loop-Helix Transcription Factor E47 Reprograms Human Pancreatic Cancer Cells to a Quiescent Acinar State With Reduced Tumorigenic Potential

    PubMed Central

    Kim, SangWun; Lahmy, Reyhaneh; Riha, Chelsea; Yang, Challeng; Jakubison, Brad L.; van Niekerk, Jaco; Staub, Claudio; Wu, Yifan; Gates, Keith; Dong, Duc Si; Konieczny, Stephen F.; Itkin-Ansari, Pamela

    2015-01-01

    Objectives Pancreatic ductal adenocarcinoma (PDA) initiates from quiescent acinar cells that attain a Kras mutation, lose signaling from basic helix-loop-helix (bHLH) transcription factors, undergo acinar-ductal metaplasia, and rapidly acquire increased growth potential. We queried whether PDA cells can be reprogrammed to revert to their original quiescent acinar cell state by shifting key transcription programs. Methods Human PDA cell lines were engineered to express an inducible form of the bHLH protein E47. Gene expression, growth, and functional studies were investigated using microarray, quantitative polymerase chain reaction, immunoblots, immunohistochemistry, small interfering RNA, chromatin immunoprecipitation analyses, and cell transplantation into mice. Results In human PDA cells, E47 activity triggers stable G0/G1 arrest, which requires the cyclin-dependent kinase inhibitor p21 and the stress response protein TP53INP1. Concurrently, E47 induces high level expression of acinar digestive enzymes and feed forward activation of the acinar maturation network regulated by the bHLH factor MIST1. Moreover, induction of E47 in human PDA cells in vitro is sufficient to inhibit tumorigenesis. Conclusions Human PDA cells retain a high degree of plasticity, which can be exploited to induce a quiescent acinar cell state with reduced tumorigenic potential. Moreover, bHLH activity is a critical node coordinately regulating human PDA cell growth versus cell fate. PMID:25894862

  18. The basic helix–loop–helix domain of maize R links transcriptional regulation and histone modifications by recruitment of an EMSY-related factor

    PubMed Central

    Hernandez, J. Marcela; Feller, Antje; Morohashi, Kengo; Frame, Kenneth; Grotewold, Erich

    2007-01-01

    The control of anthocyanin accumulation in maize by the cooperation of the basic helix–loop–helix (bHLH) protein R with the MYB transcription factor C1 provides one of the best examples of plant combinatorial transcriptional control. Establishing the function of the bHLH domain of R has remained elusive, and so far no proteins that interact with this conserved domain have been identified. We show here that the bHLH domain of R is dispensable for the activation of transiently expressed genes yet is essential for the activation of the endogenous genes in their normal chromatin environment. The activation of A1, one of the anthocyanin biosynthetic genes, is associated with increased acetylation of histone 3 (H3) at K9/K14 in the promoter region to which the C1/R complex binds. We identified R-interacting factor 1 (RIF1) as a nuclear, AGENET domain-containing EMSY-like protein that specifically interacts with the bHLH region of R. Knockdown experiments show that RIF1 is necessary for the activation of the endogenous promoters but not of transiently expressed genes. ChIP experiments established that RIF1 is tethered to the regulatory region of the A1 promoter by the C1/R complex. Together, these findings describe a function for the bHLH domain of R in linking transcriptional regulation with chromatin functions by the recruitment of an EMSY-related factor. PMID:17940002

  19. Transcriptome-wide analysis of basic helix-loop-helix transcription factors in Isatis indigotica and their methyl jasmonate responsive expression profiling.

    PubMed

    Zhang, Lei; Chen, Junfeng; Li, Qing; Chen, Wansheng

    2016-01-15

    Jasmonates (JAs) act as conserved elicitors of plant secondary metabolism. JAs perception triggers extensive transcriptional reprogramming leading to activation of the entire metabolic pathways. The family of basic helix-loop-helix (bHLH) transcription factors (TFs) has essential roles in JA signaling; however, little is known about their roles in regulation of secondary metabolites in Isatis indigotica. In this study, we identified 78 putative IibHLH sequences using the annotation of I. indigotica transcriptome. The identified proteins were characterized based on phylogenetic and conserved motif analyses. Using RNA sequencing, 16 IibHLHs showed significant positive response to MeJA (methyl jasmonate) at 1h, indicating their roles as early signaling events of JA-mediated transcriptional reprogramming. Ten IibHLHs presented co-expression pattern with biosynthetic pathway genes, suggesting their regulating role in secondary metabolite synthesis. These gene expression profiling data indicate that bHLHs can be used as candidate genes in molecular breeding programs to improve metabolite production in I. indigotica. PMID:26449398

  20. Regulatory switch enforced by basic helix-loop-helix and ACT-domain mediated dimerizations of the maize transcription factor R.

    PubMed

    Kong, Que; Pattanaik, Sitakanta; Feller, Antje; Werkman, Joshua R; Chai, Chenglin; Wang, Yongqin; Grotewold, Erich; Yuan, Ling

    2012-07-24

    The maize R2R3-MYB regulator C1 cooperates with the basic helix-loop-helix (bHLH) factor R to activate the expression of anthocyanin biosynthetic genes coordinately. As is the case for other bHLH factors, R harbors several protein-protein interaction domains. Here we show that not the classical but rather a briefly extended R bHLH region forms homodimers that bind canonical G-box DNA motifs. This bHLH DNA-binding activity is abolished if the C-terminal ACT (aspartokinase, chorismate, and TyrA) domain is licensed to homodimerize. Then the bHLH remains in the monomeric form, allowing it to interact with R-interacting factor 1 (RIF1). In this configuration, the R-RIF1 complex is recruited to the promoters of a subset of anthocyanin biosynthetic genes, such as A1, through the interaction with its MYB partner C1. If, however, the ACT domain remains monomeric, the bHLH region dimerizes and binds to G-boxes present in several anthocyanin genes, such as Bz1. Our results provide a mechanism by which a dimerization domain in a bHLH factor behaves as a switch that permits distinct configurations of a regulatory complex to be tethered to different promoters. Such a combinatorial gene regulatory framework provides one mechanism by which genes lacking obviously conserved cis-regulatory elements are regulated coordinately. PMID:22778424

  1. Genome-wide binding of the basic helix-loop-helix myogenic inhibitor musculin has substantial overlap with MyoD: implications for buffering activity

    PubMed Central

    2013-01-01

    Background Musculin (MSC) is a basic helix-loop-helix transcription factor that inhibits myogenesis during normal development and contributes to the differentiation defect in rhabdomyosarcoma. As one of many transcription factors that impede myogenesis, its binding on a genome-wide scale relative to the widespread binding of the myogenic factor MyoD is unknown. Methods Chromatin immunoprecipitation coupled to high-throughput sequencing was performed for endogenous MSC in rhabdomyosarcoma cells and its binding was compared to that of MyoD in the same type of cells. Results MSC binds throughout the genome, in a pattern very similar to MyoD. Its binding overlaps strongly with regions enriched for acetylated histone H4, as well as regions that score high for DNase hypersensitivity in human myoblasts. In contrast to MyoD, MSC has a more relaxed binding sequence preference in the nucleotides that flank the core E-box motif. Conclusions The myogenic inhibitor MSC binds throughout the genome of rhabdomyosarcoma cells, in a pattern highly similar to that of MyoD, suggesting a broad role in buffering the activity of MyoD in development and rhabdomyosarcomas. PMID:24175993

  2. The Rice Basic Helix-Loop-Helix Transcription Factor TDR INTERACTING PROTEIN2 Is a Central Switch in Early Anther Development[C][W

    PubMed Central

    Fu, Zhenzhen; Yu, Jing; Cheng, Xiaowei; Zong, Xu; Xu, Jie; Chen, Mingjiao; Li, Zongyun; Zhang, Dabing; Liang, Wanqi

    2014-01-01

    In male reproductive development in plants, meristemoid precursor cells possessing transient, stem cell–like features undergo cell divisions and differentiation to produce the anther, the male reproductive organ. The anther contains centrally positioned microsporocytes surrounded by four distinct layers of wall: the epidermis, endothecium, middle layer, and tapetum. Here, we report that the rice (Oryza sativa) basic helix-loop-helix (bHLH) protein TDR INTERACTING PROTEIN2 (TIP2) functions as a crucial switch in the meristemoid transition and differentiation during early anther development. The tip2 mutants display undifferentiated inner three anther wall layers and abort tapetal programmed cell death, causing complete male sterility. TIP2 has two paralogs in rice, TDR and EAT1, which are key regulators of tapetal programmed cell death. We revealed that TIP2 acts upstream of TDR and EAT1 and directly regulates the expression of TDR and EAT1. In addition, TIP2 can interact with TDR, indicating a role of TIP2 in later anther development. Our findings suggest that the bHLH proteins TIP2, TDR, and EAT1 play a central role in regulating differentiation, morphogenesis, and degradation of anther somatic cell layers, highlighting the role of paralogous bHLH proteins in regulating distinct steps of plant cell–type determination. PMID:24755456

  3. A basic helix-loop-helix transcription factor, PhFBH4, regulates flower senescence by modulating ethylene biosynthesis pathway in petunia

    PubMed Central

    Yin, Jing; Chang, Xiaoxiao; Kasuga, Takao; Bui, Mai; Reid, Michael S; Jiang, Cai-Zhong

    2015-01-01

    The basic helix-loop-helix (bHLH) transcription factors (TFs) play important roles in regulating multiple biological processes in plants. However, there are few reports about the function of bHLHs in flower senescence. In this study, a bHLH TF, PhFBH4, was found to be dramatically upregulated during flower senescence. Transcription of PhFBH4 is induced by plant hormones and abiotic stress treatments. Silencing of PhFBH4 using virus-induced gene silencing or an antisense approach extended flower longevity, while transgenic petunia flowers with an overexpression construct showed a reduction in flower lifespan. Abundance of transcripts of senescence-related genes (SAG12, SAG29) was significantly changed in petunia PhFBH4 transgenic flowers. Furthermore, silencing or overexpression of PhFBH4 reduced or increased, respectively, transcript abundances of important ethylene biosynthesis-related genes, ACS1 and ACO1, thereby influencing ethylene production. An electrophoretic mobility shift assay showed that the PhFBH4 protein physically interacted with the G-box cis-element in the promoter of ACS1, suggesting that ACS1 was a direct target of the PhFBH4 protein. In addition, ectopic expression of this gene altered plant development including plant height, internode length, and size of leaves and flowers, accompanied by alteration of transcript abundance of the gibberellin biosynthesis-related gene GA2OX3. Our results indicate that PhFBH4 plays an important role in regulating plant growth and development through modulating the ethylene biosynthesis pathway. PMID:26715989

  4. The poplar basic helix-loop-helix transcription factor BEE3 - Like gene affects biomass production by enhancing proliferation of xylem cells in poplar.

    PubMed

    Noh, Seol Ah; Choi, Young-Im; Cho, Jin-Seong; Lee, Hyoshin

    2015-06-19

    Brassinosteroids (BRs) play important roles in many aspects of plant growth and development, including regulation of vascular cambium activities and cell elongation. BR-induced BEE3 (brassinosteroid enhanced expression 3) is required for a proper BR response. Here, we identified a poplar (Populus alba × Populus glandulosa) BEE3-like gene, PagBEE3L, encoding a putative basic helix-loop-helix (bHLH)-type transcription factor. Expression of PagBEE3L was induced by brassinolide (BL). Transcripts of PagBEE3L were mainly detected in stems, with the internode having a low level of transcription and the node having a relatively higher level. The function of the PagBEE3L gene was investigated through phenotypic analyses with PagBEE3L-overexpressing (ox) transgenic lines. This work particularly focused on a potential role of PagBEE3L in stem growth and development of polar. The PagBEE3L-ox poplar showed thicker and longer stems than wild-type plants. The xylem cells from the stems of PagBEE3L-ox plants revealed remarkably enhanced proliferation, resulting in an earlier thickening growth than wild-type plants. Therefore, this work suggests that xylem development of poplar is accelerated in PagBEE3L-ox plants and PagBEE3L plays a role in stem growth by increasing the proliferation of xylem cells to promote the initial thickening growth of poplar stems. PMID:25935487

  5. Targeting the microphthalmia basic helix-loop-helix-leucine zipper transcription factor to a subset of E-box elements in vitro and in vivo.

    PubMed

    Aksan, I; Goding, C R

    1998-12-01

    The development of melanocytes, which are pigment-producing cells responsible for skin, hair, and eye color, is absolutely dependent on the action of the microphthalmia basic helix-loop-helix-leucine zipper (bHLH-LZ) transcription factor (Mi); mice lacking a functional Mi protein are entirely devoid of pigment cells. Mi has been shown to activate transcription of the tyrosinase, TRP-1, TRP-2, and QNR-71 genes through specific E-box elements, most notably the highly conserved M box. We investigated the mechanism which enables Mi to be recruited specifically to a restricted subset of E boxes in target promoters while being prevented from binding E-box elements in other promoters. We show both in vitro and in vivo that the presence of a T residue flanking a CATGTG E box is an essential determinant of the ability of Mi to bind DNA, and we successfully predict that the CATGTG E box from the P gene would not bind Mi. In contrast, no specific requirement for the sequences flanking a CACGTG E box was observed, and no binding to an atypical E box in the c-Kit promoter was detected. The relevance of these observations to the control of melanocyte-specific gene expression was highlighted by the fact that the E-box elements located in the tyrosinase, TRP-1, TRP-2, and QNR-71 promoters without exception possess a 5' flanking T residue which is entirely conserved between species as diverse as man and turtle. The ability of Mi to discriminate between different E-box motifs provides a mechanism to restrict the repertoire of genes which are likely to be regulated by Mi and provides insight into the ability of bHLH-LZ transcription factors to achieve the specificity required for the precise coordination of transcription during development. PMID:9819381

  6. Basic helix-loop-helix transcription factor BcbHLHpol functions as a positive regulator of pollen development in non-heading Chinese cabbage.

    PubMed

    Liu, Tongkun; Li, Ying; Zhang, Changwei; Duan, Weike; Huang, Feiyi; Hou, Xilin

    2014-12-01

    Cytoplasmic male sterility (CMS) is a common trait in higher plants, and several transcription factors regulate pollen development. Previously, we obtained a basic helix-loop-helix transcription factor, BcbHLHpol, via suppression subtractive hybridization in non-heading Chinese cabbage. However, the regulatory function of BcbHLHpol during anther and pollen development remains unclear. In this study, BcbHLHpol was cloned, and its tissue-specific expression profile was analyzed. The results of real-time polymerase chain reaction showed that BcbHLHpol was highly expressed in maintainer buds and that the transcripts of BcbHLHpol significantly decreased in the buds of pol CMS. A virus-induced gene silencing vector that targets BcbHLHpol was constructed and transformed into Brassica campestris plants to further explore the function of BcbHLHpol. Male sterility and short stature were observed in BcbHLHpol-silenced plants. The degradation of tapetal cells was inhibited in BcbHLHpol-silenced plants, and nutrients were insufficiently supplied to the microspore. These phenomena resulted in pollen abortion. This result indicates that BcbHLHpol functions as a positive regulator in pollen development. Yeast two-hybrid and bimolecular fluorescence complementation assays revealed that BcbHLHpol interacted with BcSKP1 in the nucleus. This finding suggests that BcbHLHpol and BcSKP1 are positive coordinating regulators of pollen development. Quantitative real-time PCR indicated that BcbHLHpol and BcSKP1 can be induced at low temperatures. Thus, we propose that BcbHLHpol is necessary for meiosis. This study provides insights into the regulatory functions of the BcbHLHpol network during anther development. PMID:25147023

  7. The Neurogenic Basic Helix-Loop-Helix Transcription Factor NeuroD6 Enhances Mitochondrial Biogenesis and Bioenergetics to Confer Tolerance of Neuronal PC12-NeuroD6 Cells to the Mitochondrial Stressor Rotenone

    PubMed Central

    Baxter, Kristin Kathleen; Uittenbogaard, Martine; Chiaramello, Anne

    2012-01-01

    The fundamental question of how and which neuronal specific transcription factors tailor mitochondrial bioenergetics to the need of developing neuronal cells has remained largely unexplored. In this study, we report that the neurogenic basic helix-loop-helix transcription factor NeuroD6 possesses mitochondrial biogenic properties by amplifying the mitochondrial DNA content and TFAM expression levels, a key regulator for mitochondrial biogenesis. NeuroD6-mediated increase in mitochondrial biogenesis in the neuronal progenitor-like PC12-NEUROD6 cells is concomitant with enhanced mitochondrial bioenergetic functions, including increased expression levels of specific subunits of respiratory complexes of the electron transport chain, elevated mitochondrial membrane potential and ATP levels produced by oxidative phosphorylation. Thus, NeuroD6 augments the bioenergetic capacity of PC12-NEUROD6 cells to generate an energetic reserve, which confers tolerance to the mitochondrial stressor, rotenone. We found that NeuroD6 induces an adaptive bioenergetic response throughout rotenone treatment involving maintenance of the mitochondrial membrane potential and ATP levels in conjunction with preservation of the actin network. In conclusion, our results support the concept that NeuroD6 plays an integrative role in regulating and coordinating the onset of neuronal differentiation with acquisition of adequate mitochondrial mass and energetic capacity to ensure energy demanding events, such as cytoskeletal remodeling, plasmalemmal expansion, and growth cone formation. PMID:22814253

  8. The neurogenic basic helix-loop-helix transcription factor NeuroD6 enhances mitochondrial biogenesis and bioenergetics to confer tolerance of neuronal PC12-NeuroD6 cells to the mitochondrial stressor rotenone

    SciTech Connect

    Baxter, Kristin Kathleen; Uittenbogaard, Martine; Chiaramello, Anne

    2012-10-15

    The fundamental question of how and which neuronal specific transcription factors tailor mitochondrial biogenesis and bioenergetics to the need of developing neuronal cells has remained largely unexplored. In this study, we report that the neurogenic basic helix-loop-helix transcription factor NeuroD6 possesses mitochondrial biogenic properties by amplifying the mitochondrial DNA content and TFAM expression levels, a key regulator for mitochondrial biogenesis. NeuroD6-mediated increase in mitochondrial biogenesis in the neuronal progenitor-like PC12-NEUROD6 cells is concomitant with enhanced mitochondrial bioenergetic functions, including increased expression levels of specific subunits of respiratory complexes of the electron transport chain, elevated mitochondrial membrane potential and ATP levels produced by oxidative phosphorylation. Thus, NeuroD6 augments the bioenergetic capacity of PC12-NEUROD6 cells to generate an energetic reserve, which confers tolerance to the mitochondrial stressor, rotenone. We found that NeuroD6 induces an adaptive bioenergetic response throughout rotenone treatment involving maintenance of the mitochondrial membrane potential and ATP levels in conjunction with preservation of the actin network. In conclusion, our results support the concept that NeuroD6 plays an integrative role in regulating and coordinating the onset of neuronal differentiation with acquisition of adequate mitochondrial mass and energetic capacity to ensure energy demanding events, such as cytoskeletal remodeling, plasmalemmal expansion, and growth cone formation. -- Highlights: Black-Right-Pointing-Pointer NeuroD6 induces mitochondrial biogenesis in neuroprogenitor-like cells. Black-Right-Pointing-Pointer NeuroD6 augments the bioenergetic reserve of the neuronal PC12-NeuroD6 cells. Black-Right-Pointing-Pointer NeuroD6 increases the mitochondrial membrane potential and ATP levels. Black-Right-Pointing-Pointer NeuroD6 confers tolerance to rotenone via an adaptive mitochondrial response.

  9. Yeast transcriptional activator INO2 interacts as an Ino2p/Ino4p basic helix-loop-helix heteromeric complex with the inositol/choline-responsive element necessary for expression of phospholipid biosynthetic genes in Saccharomyces cerevisiae.

    PubMed Central

    Schwank, S; Ebbert, R; Rautenstrauss, K; Schweizer, E; Schüller, H J

    1995-01-01

    Coordinate transcriptional control of yeast genes involved in phospholipid biosynthesis is mediated by the inositol/choline-responsive element (ICRE) contained in the respective promoter regions. Regulatory genes INO2 and INO4, both encoding basic helix-loop-helix (bHLH) proteins, are necessary for ICRE-dependent gene activation. By the use of size variants and by heterologous expression in E. coli we demonstrate that Ino2p and Ino4p are both necessary and sufficient for the formation of the previously described FAS binding factor 1, Fbf1, interacting with the ICRE. Formation of a heteromeric complex between Ino2p and Ino4p by means of the respective bHLH domains was demonstrated in vivo by the interaction of appropriate two-hybrid constructs and in vitro by Far-Western analyses. Neither Ino2p nor Ino4p binds to the ICRE as a homodimer. When fused to the DNA-binding domain of Gal4p, Ino2p but not Ino4p was able to activate a UASGAL-containing reporter gene even in the absence of the heterologous Fbf1 subunit. By deletion studies, two separate transcriptional activation domains were identified in the N-terminal part of Ino2p. Thus, the bHLH domains of Ino2p and Ino4p constitute the dimerization/DNA-binding module of Fbf1 mediating its interaction with the ICRE, while transcriptional activation is effected exclusively by Ino2p. Images PMID:7862526

  10. E Proteins and ID Proteins: Helix-Loop-Helix Partners in Development and Disease.

    PubMed

    Wang, Lan-Hsin; Baker, Nicholas E

    2015-11-01

    The basic Helix-Loop-Helix (bHLH) proteins represent a well-known class of transcriptional regulators. Many bHLH proteins act as heterodimers with members of a class of ubiquitous partners, the E proteins. A widely expressed class of inhibitory heterodimer partners-the Inhibitor of DNA-binding (ID) proteins-also exists. Genetic and molecular analyses in humans and in knockout mice implicate E proteins and ID proteins in a wide variety of diseases, belying the notion that they are non-specific partner proteins. Here, we explore relationships of E proteins and ID proteins to a variety of disease processes and highlight gaps in knowledge of disease mechanisms. PMID:26555048

  11. Expression of a chimeric helix-loop-helix gene, Id-SCL, in K562 human leukemic cells is associated with nuclear segmentation.

    PubMed Central

    Goldfarb, A. N.; Wolf, M. L.; Greenberg, J. M.

    1992-01-01

    We have designed a chimeric gene, Id-SCL, in which the 3' helix-loop-helix encoding portion of the presumptive oncogene SCL/tal is joined to the 5' coding portion of Id, an inhibitory helix-loop-helix gene. The predicted protein product of this chimeric gene contains the helix-loop-helix dimerization domain of SCL/tal, but, lacking a basic DNA binding domain, is predicted to have the inhibitory function of the Id product. Expression of the Id-SCL fusion gene in stably transfected K562 cells reproducibly resulted in nuclear segmentation and depressed growth rates; both of these phenotypic effects demonstrated a dosage dependence on the levels of Id-SCL mRNA and protein expressed in the various clones. Electron microscopy of cells expressing high levels of Id-SCL mRNA showed a significant increase in cytoplasmic perinuclear thin filaments and diminution of marginal heterochromatin in the nuclei. No other changes in hematopoietic differentiation status were observed in association with Id-SCL expression. Expression of intact Id and SCL/tal genes, as well as deletion mutants of Id and SCL/tal, independently transfected into K562 cells, indicated that the nuclear segmentation effect is dependent on the presence of a protein possessing a helix-loop-helix domain but lacking a basic domain. Our studies suggest that the balance of transcriptional inhibitory and stimulatory helix-loop-helix proteins in cells may be important determinants of proliferation and of structural organization within cells. Images Figure 2 Figure 3 Figure 4 Figure 5 Figure 6 Figure 8 Figure 11 PMID:1443047

  12. Suppression of mammary epithelial cell differentiation by the helix-loop-helix protein Id-1

    SciTech Connect

    Desprez, P.; Hara, E.; Bissell, M.J.

    1995-06-01

    Cell proliferation and differentiation are precisely coordinated during the development and maturation of the mammary gland, and this balance invariably is disrupted during carcinogenesis. Little is known about the cell-specific transcription factors that regulate these processes in the mammary gland. The mouse mammary epithelial cell line SCp2 grows well under standard culture conditions but arrests growth, forms alveolus-like structures, and expresses {beta}-casein, a differentiation marker, 4 to 5 days after exposure to basement membrane and lactogenic hormones (differentiation signals). The authors show that this differentiation entails a marked decline in the expression of Id-1, a helix-loop-helix (HLH) protein that inactivates basic HLH transcription factors in other cell types. SCp2 cells stably transfected with an Id-1 expression vector grew more rapidly than control cells under standard conditions, but in response to differentiation signals, they lost three-dimensional organization, invaded the basement membrane, and then resumed growth. SCp2 cells expressing an Id-1 antisense vector grew more slowly than controls; in response to differentiation signals, they remained stably growth arrested and fully differentiated, as did control cells. The authors suggest that Id-1 renders cells refractory to differentiation signals and receptive to growth signals by inactivating one or more basic HLH proteins that coordinate growth and differentiation in the mammary epithelium. 53 refs., 6 figs.

  13. Loss of the amino-terminal helix-loop-helix domain of the vav proto-oncogene activates its transforming potential.

    PubMed Central

    Katzav, S; Cleveland, J L; Heslop, H E; Pulido, D

    1991-01-01

    vav, a novel human oncogene, was originally generated in vitro by replacement of its normal 5' coding sequences with sequences from pSV2neo DNA, cotransfected as a selectable marker (S. Katzav, D. Martin-Zanca, and M. Barbacid, EMBO J. 8:2283-2290, 1989). The vav proto-oncogene is normally expressed in cells of hematopoietic origin. To determine whether the 5' rearrangement of vav or its ectopic expression in NIH 3T3 cells contributes to its transforming potential, we isolated murine and human proto-vav cDNA clones as well as human genomic clones corresponding to the 5' end of the gene. Normal proto-vav was poorly transforming in NIH 3T3 cells, whereas truncation of its 5' end greatly enhanced its transforming activity. The relative failure of full-length proto-vav cDNA clones to transform NIH 3T3 cells indicates that the transforming activity of vav is not simply due to ectopic expression. Analysis of the predicted amino terminus of the vav proto-oncogene shows that it contains a helix-loop-helix domain and a leucine zipper motif similar to that of myc family proteins, though it lacks a basic region that is usually found adjacent to helix-loop-helix domains. Loss of the helix-loop-helix domain of proto-vav, either by truncation or by rearrangement with pSV2neo sequences, activates its oncogenic potential. Images PMID:2005887

  14. BuD, a helix–loop–helix DNA-binding domain for genome modification

    SciTech Connect

    Stella, Stefano; Molina, Rafael; López-Méndez, Blanca; Juillerat, Alexandre; Bertonati, Claudia; Daboussi, Fayza; Campos-Olivas, Ramon; Duchateau, Phillippe; Montoya, Guillermo

    2014-07-01

    Crystal structures of BurrH and the BurrH–DNA complex are reported. DNA editing offers new possibilities in synthetic biology and biomedicine for modulation or modification of cellular functions to organisms. However, inaccuracy in this process may lead to genome damage. To address this important problem, a strategy allowing specific gene modification has been achieved through the addition, removal or exchange of DNA sequences using customized proteins and the endogenous DNA-repair machinery. Therefore, the engineering of specific protein–DNA interactions in protein scaffolds is key to providing ‘toolkits’ for precise genome modification or regulation of gene expression. In a search for putative DNA-binding domains, BurrH, a protein that recognizes a 19 bp DNA target, was identified. Here, its apo and DNA-bound crystal structures are reported, revealing a central region containing 19 repeats of a helix–loop–helix modular domain (BurrH domain; BuD), which identifies the DNA target by a single residue-to-nucleotide code, thus facilitating its redesign for gene targeting. New DNA-binding specificities have been engineered in this template, showing that BuD-derived nucleases (BuDNs) induce high levels of gene targeting in a locus of the human haemoglobin ? (HBB) gene close to mutations responsible for sickle-cell anaemia. Hence, the unique combination of high efficiency and specificity of the BuD arrays can push forward diverse genome-modification approaches for cell or organism redesign, opening new avenues for gene editing.

  15. Molecular cloning of ID4, a novel dominant negative helix-loop-helix human gene on chromosome 6p21.3-p22

    SciTech Connect

    Pagliuca, A.; Bartoli, P.C.; Saccone, S.

    1995-05-01

    Transcription factors containing a basic helix-loop-helix (bHLH) motif regulate the expression of tissue-specific genes in a number of mammalian and insect systems. DNA-binding activity of the bHLH proteins is dependent upon formation of homo- and/or heterodimers. Dominant negative HLH proteins (Id-related genes) also contain the HLH-dimerization domain but lack the DNA-binding basic domain. Consequently, Id proteins inhibit binding to DNA and transcriptional transactivation by heterodimerization with bHLH proteins. The authors report here the cDNA sequence of a novel human HLH gene (HGMW-approved symbol ID4) that lacks the basic domain. ID4 is differentially expressed in adult organs in four mRNA molecules, which are presumably a result of differential splicing and/or alternative usage of the polyadenylation sites. Transfection experiments indicated that enforced expression of Id-4H protein inhibits the trans-activation of the muscle creatine kinase E-box enhancer by MyoD. Finally, the authors localized the ID4 gene to the chromosome 6p21-p22 region. 18 refs., 4 figs.

  16. Molecular phylogenetic analysis of zebra finch basic helix-loop-helix transcription factors.

    PubMed

    Liu, Wuyi; Zhao, Chunjiang

    2011-04-01

    The zebra finch (Taeniopygia guttata) is an established organism for developmental, behavioral, and neurological research. In this study, we conducted a genomewide survey using the zebra finch genome project databases and identified 86 bHLH sequences in silico in the zebra finch genome. Phylogenetic analysis revealed that 85 proteins belong to 38 families with 29, 18, 18, 3, 11, and 6 bHLH members in supergroups A, B, C, D, E, and F, respectively. One orphan member belonged to none of these groups. Comparisons of zebra finch with chicken and human bHLH repertoires suggested that both humans and birds have a number of lineage-specific bHLH members. Chromosome distribution patterns and phylogenetic analysis suggest that the zebra finch bHLH members should have arisen through gene duplication. This study provides useful information for further research using zebra finch as a model system. PMID:21165766

  17. Expression of the helix-loop-helix protein inhibitor of DNA binding-1 (ID-1) is activated by all-trans retinoic acid in normal human keratinocytes

    SciTech Connect

    Villano, C.M.; White, L.A. . E-mail: lawhite@aesop.rutgers.edu

    2006-08-01

    The ID (inhibitor of differentiation or DNA binding) helix-loop-helix proteins are important mediators of cellular differentiation and proliferation in a variety of cell types through regulation of gene expression. Overexpression of the ID proteins in normal human keratinocytes results in extension of culture lifespan, indicating that these proteins are important for epidermal differentiation. Our hypothesis is that the ID proteins are targets of the retinoic acid signaling pathway in keratinocytes. Retinoids, vitamin A analogues, are powerful regulators of cell growth and differentiation and are widely used in the prevention and treatment of a variety of cancers in humans. Furthermore, retinoic acid is necessary for the maintenance of epithelial differentiation and demonstrates an inhibitory action on skin carcinogenesis. We examined the effect of all-trans retinoic acid on expression of ID-1, -2, -3, and -4 in normal human keratinocytes and found that exposure of these cells to all-trans retinoic acid causes an increase in both ID-1 and ID-3 gene expression. Furthermore, our data show that this increase is mediated by increased transcription involving several cis-acting elements in the distal portion of the promoter, including a CREB-binding site, an Egr1 element, and an YY1 site. These data demonstrate that the ID proteins are direct targets of the retinoic acid signaling pathway. Given the importance of the ID proteins to epidermal differentiation, these results suggest that IDs may be mediating some of the effects of all-trans retinoic acid in normal human keratinocytes.

  18. A new transcriptional-activation motif restricted to a class of helix-loop-helix proteins is functionally conserved in both yeast and mammalian cells.

    PubMed Central

    Quong, M W; Massari, M E; Zwart, R; Murre, C

    1993-01-01

    Previous studies demonstrated that the amino-terminal portions of E2A and E2-2 are crucial for transactivation. Subsequent findings showed that the same amino-terminal region of E2A is involved in two different translocation events contributing to the induction of a pre-B-cell acute lymphoblastic leukemia and a pro-B-cell acute lymphoblastic leukemia. These results led us to focus on the amino-terminal region of E2A to better understand its normal role in transcriptional regulation and its aberrant involvement in the two leukemias. We report here the identification of two conserved boxes in the E2A amino-terminal domain that show extensive homology within the transactivation domains of E12, E47, E2-2, HEB, and daughterless, all members of the same class of helix-loop-helix proteins. Together, both boxes are crucial for transcriptional activation and have the potential to form a new activation motif, that of a loop adjacent to an amphipathic alpha-helix, designated the loop-helix (LH) motif. A minimal region containing the LH motif is sufficient for transcriptional activation. Point mutations in the amphipathic helix of the minimal region reduce its transactivation capabilities dramatically. The same constructs expressed in yeast cells show identical patterns of activation, suggesting that the LH motif and its target proteins are functionally conserved in yeast cells. We propose that the LH motif represents a novel transactivation domain that is distinct from the previously characterized acidic blob, proline-rich, and glutamine-rich activation motifs. In addition, the LH motif is the first activation motif restricted to one class of DNA binding proteins. Images PMID:8423802

  19. Functional Isoforms of I?B Kinase ? (IKK?) Lacking Leucine Zipper and Helix-Loop-Helix Domains Reveal that IKK? and IKK? Have Different Activation Requirements

    PubMed Central

    McKenzie, Fergus R.; Connelly, Margery A.; Balzarano, Darlene; Müller, Jurgen R.; Geleziunas, Romas; Marcu, Kenneth B.

    2000-01-01

    The activity of the NF-?B family of transcription factors is regulated principally by phosphorylation and subsequent degradation of their inhibitory I?B subunits. Site-specific serine phosphorylation of I?Bs by two I?B kinases (IKK? [also known as CHUK] and IKK?) targets them for proteolysis. IKK? and -? have a unique structure, with an amino-terminal serine-threonine kinase catalytic domain and carboxy-proximal helix-loop-helix (HLH) and leucine zipper-like (LZip) amphipathic ?-helical domains. Here, we describe the properties of two novel cellular isoforms of IKK?: IKK?-?H and IKK?-?LH. IKK?-?H and IKK?-?LH are differentially spliced isoforms of the IKK? mRNA lacking its HLH domain and both its LZip and HLH domains, respectively. IKK? is the major RNA species in most murine cells and tissues, except for activated T lymphocytes and the brain, where the alternatively spliced isoforms predominate. Remarkably, IKK?-?H and IKK?-?LH, like IKK?, respond to tumor necrosis factor alpha stimulation to potentiate NF-?B activation in HEK293 cells. A mutant, catalytically inactive form of IKK? blocked IKK?-, IKK?-?H-, and IKK?-?LH-mediated NF-?B activation. Akin to IKK?, its carboxy-terminally truncated isoforms associated with the upstream activator NIK (NF-?B-inducing kinase). In contrast to IKK?, IKK?-?LH failed to associate with either itself, IKK?, IKK?, or NEMO-IKK?-IKKAP1, while IKK?-?H complexed with IKK? and IKK? but not with NEMO. Interestingly, each IKK? isoform rescued HEK293 cells from the inhibitory effects of a dominant-negative NEMO mutant, while IKK? could not. IKK?-?Cm, a recombinant mutant of IKK? structurally akin to IKK?-?LH, was equally functional in these assays, but in sharp contrast, IKK?-?Cm, a structurally analogous mutant of IKK?, was inactive. Our results demonstrate that the functional roles of seemingly analogous domains in IKK? and IKK? need not be equivalent and can also exhibit different contextual dependencies. The existence of cytokine-inducible IKK?-?H and IKK?-?LH isoforms illustrates potential modes of NF-?B activation, which are not subject to the same in vivo regulatory constraints as either IKK? or IKK?. PMID:10733566

  20. The Basic Helix-Loop-Helix Transcription Factors Myogenin and Id2 Mediate Specific Induction of Caveolin-3 Gene Expression during

    E-print Network

    , California 94143-0520 Caveolin-3 protein is the only member of the caveolin family that shows a unique muscle growth factor receptors (4­6). The caveolin family comprises three members, caveolin-1, caveolin-2 caveolin-3 expression is restricted to striated muscle tissue (7, 8). During early muscle development, both

  1. High AN1 variability and interaction with basic helix-loop-helix co-factors related to anthocyanin biosynthesis in potato leaves.

    PubMed

    D'Amelia, Vincenzo; Aversano, Riccardo; Batelli, Giorgia; Caruso, Immacolata; Castellano Moreno, Mar; Castro-Sanz, Ana Beatriz; Chiaiese, Pasquale; Fasano, Carlo; Palomba, Francesca; Carputo, Domenico

    2014-11-01

    AN1 is a regulatory gene that promotes anthocyanin biosynthesis in potato tubers and encodes a R2R3 MYB transcription factor. However, no clear evidence implicates AN1 in anthocyanin production in leaves, where these pigments might enhance environmental stress tolerance. In our study we found that AN1 displays intraspecific sequence variability in both coding/non-coding regions and in the promoter, and that its expression is associated with high anthocyanin content in leaves of commercial potatoes. Expression analysis provided evidence that leaf pigmentation is associated to AN1 expression and that StJAF13 acts as putative AN1 co-regulator for anthocyanin gene expression in leaves of the red leaf variety 'Magenta Love,' while a concomitant expression of StbHLH1 may contribute to anthocyanin accumulation in leaves of 'Double Fun.' Yeast two-hybrid experiments confirmed that AN1 interacts with StbHLH1 and StJAF13 and the latter interaction was verified and localized in the cell nucleus by bimolecular fluorescence complementation assays. In addition, transgenic tobacco (Nicotiana tabacum) overexpressing a combination of either AN1 with StJAF13 or AN1 with StbHLH1 showed deeper purple pigmentation with respect to AN1 alone. This further confirmed AN1/StJAF13 and AN1/StbHLH1 interactions. Our findings demonstrate that the classical loci identified for potato leaf anthocyanin accumulation correspond to AN1 and may represent an important step to expand our knowledge on the molecular mechanisms underlying anthocyanin biosynthesis in different plant tissues. PMID:25159050

  2. Identifying Novel Helix-Loop-Helix Genes in "Caenorhabditis elegans" through a Classroom Demonstration of Functional Genomics

    ERIC Educational Resources Information Center

    Griffin, Vernetta; McMiller, Tracee; Jones, Erika; Johnson, Casonya M.

    2003-01-01

    A 14-week, undergraduate-level Genetics and Population Biology course at Morgan State University was modified to include a demonstration of functional genomics in the research laboratory. Students performed a rudimentary sequence analysis of the "Caenorhabditis elegans" genome and further characterized three sequences that were predicted to encode…

  3. Protein- mediated enamel mineralization

    PubMed Central

    Moradian-Oldak, Janet

    2012-01-01

    Enamel is a hard nanocomposite bioceramic with significant resilience that protects the mammalian tooth from external physical and chemical damages. The remarkable mechanical properties of enamel are associated with its hierarchical structural organization and its thorough connection with underlying dentin. This dynamic mineralizing system offers scientists a wealth of information that allows the study of basic principals of organic matrix-mediated biomineralization and can potentially be utilized in the fields of material science and engineering for development and design of biomimetic materials. This chapter will provide a brief overview of enamel hierarchical structure and properties as well as the process and stages of amelogenesis. Particular emphasis is given to current knowledge of extracellular matrix protein and proteinases, and the structural chemistry of the matrix components and their putative functions. The chapter will conclude by discussing the potential of enamel for regrowth. PMID:22652761

  4. Role of the ubiquitin-proteasome pathway in the inner ear : identification of an E3 ubiquitin ligase for Atoh1

    E-print Network

    Cheng, Yen-Fu

    2014-01-01

    Atoh1, the proneural basic-helix-loop-helix transcription factor, is critical for the differentiation of inner ear hair cells. Hair cells do not develop in mice that lack Atoh1, and overexpression of the transcription ...

  5. Transcriptional regulation of neurodevelopmental and metabolic pathways by the psychiatric illness candidate gene NPAS3 

    E-print Network

    Sha, Li

    2011-07-05

    The basic helix-loop-helix PAS domain transcription factor gene NPAS3 is a risk factor for psychiatric disorders. A knockout mouse model also exhibits behavioural and adult neurogenesis deficits consistent with human ...

  6. Recurrent Mutations in the Basic Domain of TWIST2 Cause Ablepharon Macrostomia and Barber-Say Syndromes

    PubMed Central

    Marchegiani, Shannon; Davis, Taylor; Tessadori, Federico; van Haaften, Gijs; Brancati, Francesco; Hoischen, Alexander; Huang, Haigen; Valkanas, Elise; Pusey, Barbara; Schanze, Denny; Venselaar, Hanka; Vulto-van Silfhout, Anneke T.; Wolfe, Lynne A.; Tifft, Cynthia J.; Zerfas, Patricia M.; Zambruno, Giovanna; Kariminejad, Ariana; Sabbagh-Kermani, Farahnaz; Lee, Janice; Tsokos, Maria G.; Lee, Chyi-Chia R.; Ferraz, Victor; da Silva, Eduarda Morgana; Stevens, Cathy A.; Roche, Nathalie; Bartsch, Oliver; Farndon, Peter; Bermejo-Sanchez, Eva; Brooks, Brian P.; Maduro, Valerie; Dallapiccola, Bruno; Ramos, Feliciano J.; Chung, Hon-Yin Brian; Le Caignec, Cédric; Martins, Fabiana; Jacyk, Witold K.; Mazzanti, Laura; Brunner, Han G.; Bakkers, Jeroen; Lin, Shuo; Malicdan, May Christine V.; Boerkoel, Cornelius F.; Gahl, William A.; de Vries, Bert B.A.; van Haelst, Mieke M.; Zenker, Martin; Markello, Thomas C.

    2015-01-01

    Ablepharon macrostomia syndrome (AMS) and Barber-Say syndrome (BSS) are rare congenital ectodermal dysplasias characterized by similar clinical features. To establish the genetic basis of AMS and BSS, we performed extensive clinical phenotyping, whole exome and candidate gene sequencing, and functional validations. We identified a recurrent de novo mutation in TWIST2 in seven independent AMS-affected families, as well as another recurrent de novo mutation affecting the same amino acid in ten independent BSS-affected families. Moreover, a genotype-phenotype correlation was observed, because the two syndromes differed based solely upon the nature of the substituting amino acid: a lysine at TWIST2 residue 75 resulted in AMS, whereas a glutamine or alanine yielded BSS. TWIST2 encodes a basic helix-loop-helix transcription factor that regulates the development of mesenchymal tissues. All identified mutations fell in the basic domain of TWIST2 and altered the DNA-binding pattern of Flag-TWIST2 in HeLa cells. Comparison of wild-type and mutant TWIST2 expressed in zebrafish identified abnormal developmental phenotypes and widespread transcriptome changes. Our results suggest that autosomal-dominant TWIST2 mutations cause AMS or BSS by inducing protean effects on the transcription factor’s DNA binding. PMID:26119818

  7. Recurrent Mutations in the Basic Domain of TWIST2 Cause Ablepharon Macrostomia and Barber-Say Syndromes.

    PubMed

    Marchegiani, Shannon; Davis, Taylor; Tessadori, Federico; van Haaften, Gijs; Brancati, Francesco; Hoischen, Alexander; Huang, Haigen; Valkanas, Elise; Pusey, Barbara; Schanze, Denny; Venselaar, Hanka; Vulto-van Silfhout, Anneke T; Wolfe, Lynne A; Tifft, Cynthia J; Zerfas, Patricia M; Zambruno, Giovanna; Kariminejad, Ariana; Sabbagh-Kermani, Farahnaz; Lee, Janice; Tsokos, Maria G; Lee, Chyi-Chia R; Ferraz, Victor; da Silva, Eduarda Morgana; Stevens, Cathy A; Roche, Nathalie; Bartsch, Oliver; Farndon, Peter; Bermejo-Sanchez, Eva; Brooks, Brian P; Maduro, Valerie; Dallapiccola, Bruno; Ramos, Feliciano J; Chung, Hon-Yin Brian; Le Caignec, Cédric; Martins, Fabiana; Jacyk, Witold K; Mazzanti, Laura; Brunner, Han G; Bakkers, Jeroen; Lin, Shuo; Malicdan, May Christine V; Boerkoel, Cornelius F; Gahl, William A; de Vries, Bert B A; van Haelst, Mieke M; Zenker, Martin; Markello, Thomas C

    2015-07-01

    Ablepharon macrostomia syndrome (AMS) and Barber-Say syndrome (BSS) are rare congenital ectodermal dysplasias characterized by similar clinical features. To establish the genetic basis of AMS and BSS, we performed extensive clinical phenotyping, whole exome and candidate gene sequencing, and functional validations. We identified a recurrent de novo mutation in TWIST2 in seven independent AMS-affected families, as well as another recurrent de novo mutation affecting the same amino acid in ten independent BSS-affected families. Moreover, a genotype-phenotype correlation was observed, because the two syndromes differed based solely upon the nature of the substituting amino acid: a lysine at TWIST2 residue 75 resulted in AMS, whereas a glutamine or alanine yielded BSS. TWIST2 encodes a basic helix-loop-helix transcription factor that regulates the development of mesenchymal tissues. All identified mutations fell in the basic domain of TWIST2 and altered the DNA-binding pattern of Flag-TWIST2 in HeLa cells. Comparison of wild-type and mutant TWIST2 expressed in zebrafish identified abnormal developmental phenotypes and widespread transcriptome changes. Our results suggest that autosomal-dominant TWIST2 mutations cause AMS or BSS by inducing protean effects on the transcription factor's DNA binding. PMID:26119818

  8. Metamorphic proteins mediate evolutionary transitions of structure

    E-print Network

    Tawfik, Dan S.

    Metamorphic proteins mediate evolutionary transitions of structure Itamar Yadida , Noam. Such metamorphic proteins provide a means of facilitating the evolution of new folds and ar- chitectures. However, because natural folds emerged at the early stages of evolution, the potential role of metamorphic

  9. The Role of single minded 2 short in mammary gland development and breast cancer 

    E-print Network

    Kwak, Hyeong-il

    2009-05-15

    Single minded 2 (Sim2) is a member of the basic helix-loop-helix Per-ARNT-Sim (Period-Arylhydrocarbon Nuclear Translocator-Single minded) family. Human SIM2 is involved in the etiology of the Down’s phenotype. In addition ...

  10. The Search for Endogenous Activators of the Aryl Hydrocarbon Linh P. Nguyen and Christopher A. Bradfield*

    E-print Network

    Bradfield, Christopher A.

    . Known Ligands of the AHR 105 7. Xenobiotic Ligands 105 7.1. Halogenated Dioxins and Related Compounds of halogenated dioxins demonstrate mechanistically how certain classes of hazardous chemicals exert,3,7,8-tetrachlorodibenzo-p-dioxin; bHLH, basic helix­loop­helix; PAS, PER-ARNT-SIM; ARNT, aryl hydrocarbon receptor nuclear

  11. THEJOURNALOF BIOLCGICAL CHEMISTRY 0 1994 by The American Society for Biochemistry and Molecular Biolom, Inc

    E-print Network

    Bradfield, Christopher A.

    Institutes of Health (Grants ES05703, T32 ES07124, and T32 CA09560).The costs of publication of this article; DRE, dioxin responsive element; bHLH, basic region helix-loop-helix; hsp90, 90-kDa heat shock protein

  12. FASTING AND REFEEDING EFFECTS THE EXPRESSION OF THE INHIBITOR OF DNA BINDING (ID)GENES IN RAINBOW TROUT (ONCORHYNCHUS MYKISS) MUSCLE

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The ID (Inhibitor of DNA Binding/Differentiation) proteins are a family of dominant negative regulators of the basic helix-loop-helix (bHLH) transcription factors, shown in mammals to delay cell differentiation and prolong proliferation. In the current study we investigated the effects of fasting a...

  13. Phytochrome Induces Rapid PIF5 Phosphorylation and Degradation in Response to Red-Light Activation

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The phytochrome (phy) family of sensory photoreceptors (phyA–phyE in Arabidopsis thaliana) induces changes in target-gene expression upon light-induced translocation to the nucleus, where certain members interact with selected members of the constitutively nuclear basic helix-loop-helix transcriptio...

  14. Mechanistic duality of transcription factor function in phytochrome signaling

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The phytochrome (phy) family of sensory photoreceptors (phyA–E in Arabidopsis) elicit changes in gene expression after light-induced migration to the nucleus, where they interact with basic helix–loop–helix transcription factors, such as phytochrome-interacting factor 3 (PIF3). The mechanism by whic...

  15. Overexpression of TaVRN1 in Arabidopsis Promotes Early Flowering and Alters Development

    E-print Network

    Sarhan, Fathey

    phase in wheat. The accumulation of TaVRN1 transcripts in winter wheat probably requires the down of modified plant architecture. The ectopic expression causes an overexpression of the AP1 and MAX4 genes -- Wheat. Abbreviations: bHLH, basic helix­loop­helix; EMSA, elec- trophoretic mobility shift assay; GUS, b

  16. Covalent modification and intrinsic disorder in the stability of the proneural protein Neurogenin 2

    E-print Network

    McDowell, Gary Steven

    2011-10-11

    Neurogenin 2 (Ngn2) is a basic Helix-Loop-Helix (bHLH) transcription factor regulating differentiation and cell cycle exit in the developing brain. By transcriptional upregulation of a cascade of other bHLH factors, neural progenitor cells exit...

  17. Out of the dark: how the PIFs are unmasking a dual temporal mechanism of phytochrome signalling

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Following light-induced nuclear translocation, the phytochromes induce changes in gene expression to regulate plant development. PIF3 and other PIFs (phytochrome-interacting factors), members of the bHLH (basic helix–loop–helix) family of transcriptional regulators, interact specifically with the ac...

  18. CLOCK, an essential pacemaker component, controls expression

    E-print Network

    Halazonetis, Thanos

    , is expressed according to a robust daily rhythm in the suprachiasmatic nucleus and several peripheral tissues expression. Here we present evidence that circadian Dbp transcription requires the basic helix­loop­helix­PAS protein CLOCK, an essential component of the negative-feedback circuitry generating circadian oscillations

  19. Mechanics of Protein-Mediated DNA Looping

    NASA Astrophysics Data System (ADS)

    Meiners, Jens-Christian

    2009-03-01

    The formation of looped DNA-protein complexes in which a protein or protein assembly binds to multiple distant operator sites on the DNA is a common feature for many regulatory schemes on the transcriptional level. In a living cell, a multitude of mechanical forces and constraints act on these complexes, and it is imperative to understand their effects on biological function. For this aim, we study the lactose repressor as a model system for protein-mediated DNA looping in single-molecule experiments. Using a novel axial constant-force optical trapping scheme that allows us to manipulate sub-micron DNA fragments with well-controlled forces down to the 10 fN range, we show that mechanical tension in the substrate DNA of hundred femtonewton is sufficient to disrupt the loop formation process, which suggests that such mechanical tension may provide a mechanical pathway to controlling gene expression in vivo. From the force sensitivity of the loop formation process, we can also infer the topology of the looped complex; in our case an antiparallel conformation. In addition, we will present new tethered-particle microscopy data that shows lifetimes of the looped complexes that are two to three orders of magnitude shorter than those measured in biochemical competition assays and discuss possible interpretations, including the suggestion that operator binding of the lactose repressor tetramer leads to a destabilization of the dimer-dimer interface and that thus the loop breakdown process is mostly a dissociation of the tetramer into two dimers, instead, as widely assumed, an unbinding of the tetramer from the DNA.

  20. A Minimal Model for G ProteinMediated Synaptic Facilitation and Depression

    E-print Network

    A Minimal Model for G Protein­Mediated Synaptic Facilitation and Depression Richard Bertram,1, and Gerald W. Zamponi. A minimal model for G protein­ mediated synaptic facilitation and depression. J that G protein action can provide a mechanism for either short-term synaptic facilitation or depression

  1. Creating cellular diversity through transcription factor competition

    E-print Network

    Göttgens, Berthold

    2015-02-13

    through Transcription Factor Competition Berthold Göttgens Cambridge Institute for Medical Research & Wellcome Trust and MRC Stem Cell Institute, University of Cambridge, Hills Road, Cambridge CB2 0XY, UK Tel: +44-1223-336829 Fax: +44... , and thus determine which mature tissue a given cel will differentiate into. Org et al (Org et al, 2015) in this issue of the EMBO Journal investigated this question by studying the basic helix-loop-helix TF Scl, also known as Tal1. The Scl gene...

  2. Effect of supercoiling on formation of protein mediated DNA loops

    E-print Network

    Purohit, Prashant K

    2015-01-01

    DNA loop formation is one of several mechanisms used by organisms to regulate genes. The free energy of forming a loop is an important factor in determining whether the associated gene is switched on or off. In this paper we use an elastic rod model of DNA to determine the free energy of forming short (50--100 basepair), protein mediated DNA loops. Superhelical stress in the DNA of living cells is a critical factor determining the energetics of loop formation, and we explicitly account for it in our calculations. The repressor protein itself is regarded as a rigid coupler; its geometry enters the problem through the boundary conditions it applies on the DNA. We show that a theory with these ingredients is sufficient to explain certain features observed in modulation of in vivo gene activity as a function of the distance between operator sites for the lac repressor. We also use our theory to make quantitative predictions for the dependence of looping on superhelical stress, which may be testable both in vivo a...

  3. Prostacyclin-induced hyperthermia - Implication of a protein mediator

    NASA Technical Reports Server (NTRS)

    Kandasamy, S. B.; Williams, B. A.

    1982-01-01

    The mechanism of the prostacyclin-linked hyperthermia is studied in rabbits. Results show that intracerebroventricular administration of prostacyclin (PGI2) induces dose-related hyperthermia at room temperature (21 C), as well as at low (4 C) and high (30 C) ambient temperatures. It is found that this PGI2-induced hyperthermia is not mediated by its stable metabolite 6-keto prostaglandin F-1(alpha). Only one of the three anion transport systems, the liver transport system, appears to be important to the central inactivation of pyrogen, prostaglandin E2, and PGI2. Phenoxybenzamine and pimozide have no thermolytic effect on PGI2-induced hyperthermia, while PGI2 still induces hyperthermia after norepinephrine (NE) and dopamine levels are depleted by 6-hydroxydopamine. Indomethacin and SC-19220 (a PG antagonist) do not antagonize PGI2 induced hyperthermia, while theophylline does not accentuate the PGI2-induced hyperthermia. However, the hyperthermic response to PGI2 is attenuated by central administration of the protein synthesis inhibitor, anisomycin. It is concluded that PGI2-induced hyperthermia is not induced by NE, dopamine, or cyclic AMP, but rather that a protein mediator is implicated in the induction of fever by PG12.

  4. Armet is an effector protein mediating aphid-plant interactions.

    PubMed

    Wang, Wei; Dai, Huaien; Zhang, Yi; Chandrasekar, Raman; Luo, Lan; Hiromasa, Yasuaki; Sheng, Changzhong; Peng, Gongxin; Chen, Shaoliang; Tomich, John M; Reese, John; Edwards, Owain; Kang, Le; Reeck, Gerald; Cui, Feng

    2015-05-01

    Aphid saliva is predicted to contain proteins that modulate plant defenses and facilitate feeding. Armet is a well-characterized bifunctional protein in mammalian systems. Here we report a new role of Armet, namely as an effector protein in the pea aphid, Acyrthosiphon pisum. Pea aphid Armet's physical and chemical properties and its intracellular role are comparable to those reported for mammalian Armets. Uniquely, we detected Armet in aphid watery saliva and in the phloem sap of fava beans fed on by aphids. Armet's transcript level is several times higher in the salivary gland when aphids feed on bean plants than when they feed on an artificial diet. Knockdown of the Armet transcript by RNA interference disturbs aphid feeding behavior on fava beans measured by the electrical penetration graph technique and leads to a shortened life span. Inoculation of pea aphid Armet protein into tobacco leaves induced a transcriptional response that included pathogen-responsive genes. The data suggest that Armet is an effector protein mediating aphid-plant interactions. PMID:25678626

  5. Nucleic Acid Conformational Changes Essential for HIV-1 Nucleocapsid Protein-mediated Inhibition of

    E-print Network

    Levin, Judith G.

    Nucleic Acid Conformational Changes Essential for HIV-1 Nucleocapsid Protein-mediated Inhibition) is a nucleic acid chaperone protein that has been shown to greatly facilitate the nucleic acid rearrangements and a TAR-containing acceptor RNA molecule, we find that when both nucleic acids are present, NC facilitates

  6. Protein-mediated loops and phase transition in nonthermal denaturation of DNA This article has been downloaded from IOPscience. Please scroll down to see the full text article.

    E-print Network

    Protein-mediated loops and phase transition in nonthermal denaturation of DNA This article has been and Experiment Protein-mediated loops and phase transition in nonthermal denaturation of DNA Karen G Petrosyan a statistical mechanical model to study nonthermal denaturation of DNA in the presence of protein-mediated loops

  7. The SebHLH transcription factor mediates trans-activation of the SeFAD2 gene promoter through binding to E- and G-box elements.

    PubMed

    Kim, Mi Jung; Kim, Jeong-Kook; Shin, Jeong Sheop; Suh, Mi Chung

    2007-07-01

    Microsomal oleic acid desaturase (FAD2) catalyzes the first extra-plastidial desaturation in plants, converting oleic acid to linoleic acid, which is a major constituent in all cellular membranes as well as in seed storage oils. Seed-specific FAD2 (SeFAD2) produced 40% of linoleic acids in the total fatty acids of sesame (Sesamum indicum) seeds. The expression of SeFAD2 transcripts was spatially and temporally controlled during seed development. To investigate the regulatory mechanism controlling seed-specific SeFAD2 expression, we isolated a well-matched sequence homologous to the basic region/helix-loop-helix proteins by yeast one-hybrid screening and named it SebHLH. SebHLH transcripts were expressed in developing seeds and roots of sesame. SebHLH:GFP fusion protein localized in the nucleus. Recombinant SebHLH protein bound E-box (CANNTG) and G-box (CACGTG) elements in the region from -179 to -53 of the SeFAD2 gene promoter, and the external C and G nucleotides in the E- and G-box motifs were essential for SebHLH protein binding. The SebHLH gene, under the CaMV35S promoter, and the GUS reporter gene driven by E- and G-box motifs were co-expressed in developing sesame seeds and Arabidopsis transgenic leaves. This co-expression demonstrated that SebHLH protein mediates transactivation of the SeFAD2 gene promoter through binding to E- and G-box elements. E- or G-box elements frequently occur in the 5'-flanking region of genes that are involved in triacylglycerol biosynthesis and that exhibit seed-specific expression in Arabidopsis and other plants, suggesting that bHLH transcription factors play a key role in the transcriptional regulation of genes related to storage lipid biosynthesis and accumulation during seed development. PMID:17420955

  8. Protein-mediated Loops and Phase Transition in Nonthermal Denaturation of DNA

    E-print Network

    K. G. Petrosyan; Chin-Kun Hu

    2009-12-21

    We use a statistical mechanical model to study nonthermal denaturation of DNA in the presence of protein-mediated loops. We find that looping proteins which randomly link DNA bases located at a distance along the chain could cause a first-order phase transition. We estimate the denaturation transition time near the phase transition, which can be compared with experimental data. The model describes the formation of multiple loops via dynamical (fluctuational) linking between looping proteins, that is essential in many cellular biological processes.

  9. Autophagy deficiency stabilizes TWIST1 to promote epithelial-mesenchymal transition

    PubMed Central

    Qiang, Lei; He, Yu-Ying

    2014-01-01

    The transcription factor TWIST1 is a basic helix-loop-helix protein that regulates epithelial-mesenchymal transition (EMT) in early embryonic morphogenesis, cancer development, and cancer metastasis. The regulation of TWIST1 remains poorly understood. Recently, we found that autophagy deficiency stabilizes TWIST1 protein through SQSTM1/p62 accumulation. SQSTM1 binds with TWIST1 to inhibit TWIST1 degradation in both autophagosomes and proteasomes. SQSTM1-mediated TWIST1 stabilization promotes EMT in vitro, and tumor growth and metastasis in mice. We propose autophagy as a new mechanism to control the TWIST1 protein levels and activity in cancer development and progression. PMID:25126736

  10. Tipping the MYC–MIZ1 balance: targeting the HUWE1 ubiquitin ligase selectively blocks MYC-activated genes

    PubMed Central

    Schaub, Franz X; Cleveland, John L

    2014-01-01

    MYC family oncoproteins (MYC, N-MYC and L-MYC) function as basic helix-loop-helix-leucine zipper (bHLH-Zip) transcription factors that are activated (i.e., overexpressed) in well over half of all human malignancies (Boxer & Dang, 2001; Beroukhim et al, 2010). In this issue of EMBO Molecular Medicine, Eilers and colleagues (Peter et al, 2014) describe a novel approach to disable MYC, whereby inhibition of the ubiquitin ligase HUWE1 stabilizes MIZ1 and leads to the selective repression of MYC-activated target genes. See also: S Peter et al (December 2014) PMID:25368331

  11. Tipping the MYC-MIZ1 balance: targeting the HUWE1 ubiquitin ligase selectively blocks MYC-activated genes.

    PubMed

    Schaub, Franz X; Cleveland, John L

    2014-12-01

    MYC family oncoproteins (MYC, N?MYC and L?MYC) function as basic helix?loop?helix?leucine zipper (bHLH?Zip) transcription factors that are activated (i.e., overexpressed) in well over half of all human malignancies (Boxer & Dang, 2001; Beroukhim et al, 2010). In this issue of EMBO Molecular Medicine, Eilers and colleagues (Peter et al, 2014) describe a novel approach to disable MYC, whereby inhibition of the ubiquitin ligase HUWE1 stabilizes MIZ1 and leads to the selective repression of MYC?activated target genes. PMID:25368331

  12. The first Hes1 dimer inhibitors from natural products.

    PubMed

    Arai, Midori A; Masada, Ayako; Ohtsuka, Toshiyuki; Kageyama, Ryoichiro; Ishibashi, Masami

    2009-10-01

    In the present study, we developed a high-throughput screening system for small molecule-inhibitors of the basic helix-loop-helix (bHLH) transcriptional repressor factor Hes1. Successful dimerization of Hes1 immobilized on a microplate and fluorophore (Cy3)-labelled Hes1 was confirmed. Using this system, several natural products were identified as the first Hes1 dimer inhibitors. Of these, two compounds which were isolated from myxomycetes (true slime molds) inhibited Hes1 from N box-dependent suppression of the gene expression in C3H10T1/2 cells. PMID:19716294

  13. A versatile set of ligation-independent cloning vectors for functional studies in plants.

    PubMed

    De Rybel, Bert; van den Berg, Willy; Lokerse, Annemarie; Liao, Che-Yang; van Mourik, Hilda; Möller, Barbara; Peris, Cristina Llavata; Weijers, Dolf

    2011-07-01

    With plant molecular biology entering the omics era, there is a need for simple cloning strategies that allow high throughput to systematically study the expression and function of large numbers of genes. Such strategies would facilitate the analysis of gene (sub)families and/or sets of coexpressed genes identified by transcriptomics. Here, we provide a set of 34 ligation-independent cloning (LIC) binary vectors for expression analysis, protein localization studies, and misexpression that will be made freely available. This set of plant LIC vectors offers a fast alternative to standard cloning strategies involving ligase or recombination enzyme technology. We demonstrate the use of this strategy and our new vectors by analyzing the expression domains of genes belonging to two subclades of the basic helix-loop-helix transcription factor family. We show that neither the closest homologs of TARGET OF MONOPTEROS7 (TMO7/ATBS1) nor the members of the ATBS1 INTERACTING FACTOR subclade of putative TMO7 interactors are expressed in the embryo and that there is very limited coexpression in the primary root meristem. This suggests that these basic helix-loop-helix transcription factors are most likely not involved in TMO7-dependent root meristem initiation. PMID:21562332

  14. The MYB182 Protein Down-Regulates Proanthocyanidin and Anthocyanin Biosynthesis in Poplar by Repressing Both Structural and Regulatory Flavonoid Genes1[OPEN

    PubMed Central

    Yoshida, Kazuko; Ma, Dawei; Constabel, C. Peter

    2015-01-01

    Trees in the genus Populus (poplar) contain phenolic secondary metabolites including the proanthocyanidins (PAs), which help to adapt these widespread trees to diverse environments. The transcriptional activation of PA biosynthesis in response to herbivory and ultraviolet light stress has been documented in poplar leaves, and a regulator of this process, the R2R3-MYB transcription factor MYB134, has been identified. MYB134-overexpressing transgenic plants show a strong high-PA phenotype. Analysis of these transgenic plants suggested the involvement of additional MYB transcription factors, including repressor-like MYB factors. Here, MYB182, a subgroup 4 MYB factor, was found to act as a negative regulator of the flavonoid pathway. Overexpression of MYB182 in hairy root culture and whole poplar plants led to reduced PA and anthocyanin levels as well as a reduction in the expression of key flavonoid genes. Similarly, a reduced accumulation of transcripts of a MYB PA activator and a basic helix-loop-helix cofactor was observed in MYB182-overexpressing hairy roots. Transient promoter activation assays in poplar cell culture demonstrated that MYB182 can disrupt transcriptional activation by MYB134 and that the basic helix-loop-helix-binding motif of MYB182 was essential for repression. Microarray analysis of transgenic plants demonstrated that down-regulated targets of MYB182 also include shikimate pathway genes. This work shows that MYB182 plays an important role in the fine-tuning of MYB134-mediated flavonoid metabolism. PMID:25624398

  15. Down-regulation of ubiquitin ligase Cbl induced by twist haploinsufficiency in Saethre-Chotzen syndrome results in increased PI3K/Akt signaling and osteoblast proliferation.

    PubMed

    Guenou, Hind; Kaabeche, Karim; Dufour, Cécilie; Miraoui, Hichem; Marie, Pierre J

    2006-10-01

    Genetic mutations of Twist, a basic helix-loop-helix transcription factor, induce premature fusion of cranial sutures in Saethre-Chotzen syndrome (SCS). We report here a previously undescribed mechanism involved in the altered osteoblastogenesis in SCS. Cranial osteoblasts from an SCS patient with a Twist mutation causing basic helix-loop-helix deletion exhibited decreased expression of E3 ubiquitin ligase Cbl compared with wild-type osteoblasts. This was associated with decreased ubiquitin-mediated degradation of phosphatidyl inositol 3 kinase (PI3K) and increased PI3K expression and PI3K/Akt signaling. Increased PI3K immunoreactivity was also found in osteoblasts in histological sections of affected cranial sutures from SCS patients. Transfection with Twist or Cbl abolished the increased PI3K/Akt signaling in Twist mutant osteoblasts. Forced overexpression of Cbl did not correct the altered expression of osteoblast differentiation markers in Twist mutant cells. In contrast, pharmacological inhibition of PI3K/Akt, but not ERK signaling, corrected the increased cell growth in Twist mutant osteoblasts. The results show that Twist haploinsufficiency results in decreased Cbl-mediated PI3K degradation in osteoblasts, causing PI3K accumulation and activation of PI3K/Akt-dependent osteoblast growth. This provides genetic and biochemical evidence for a role for Cbl-mediated PI3K signaling in the altered osteoblast phenotype induced by Twist haploinsufficiency in SCS. PMID:17003487

  16. Down-Regulation of Ubiquitin Ligase Cbl Induced by Twist Haploinsufficiency in Saethre-Chotzen Syndrome Results in Increased PI3K/Akt Signaling and Osteoblast Proliferation

    PubMed Central

    Guenou, Hind; Kaabeche, Karim; Dufour, Cécilie; Miraoui, Hichem; Marie, Pierre J.

    2006-01-01

    Genetic mutations of Twist, a basic helix-loop-helix transcription factor, induce premature fusion of cranial sutures in Saethre-Chotzen syndrome (SCS). We report here a previously undescribed mechanism involved in the altered osteoblastogenesis in SCS. Cranial osteoblasts from an SCS patient with a Twist mutation causing basic helix-loop-helix deletion exhibited decreased expression of E3 ubiquitin ligase Cbl compared with wild-type osteoblasts. This was associated with decreased ubiquitin-mediated degradation of phosphatidyl inositol 3 kinase (PI3K) and increased PI3K expression and PI3K/Akt signaling. Increased PI3K immunoreactivity was also found in osteoblasts in histological sections of affected cranial sutures from SCS patients. Transfection with Twist or Cbl abolished the increased PI3K/Akt signaling in Twist mutant osteoblasts. Forced overexpression of Cbl did not correct the altered expression of osteoblast differentiation markers in Twist mutant cells. In contrast, pharmacological inhibition of PI3K/Akt, but not ERK signaling, corrected the increased cell growth in Twist mutant osteoblasts. The results show that Twist haploinsufficiency results in decreased Cbl-mediated PI3K degradation in osteoblasts, causing PI3K accumulation and activation of PI3K/Akt-dependent osteoblast growth. This provides genetic and biochemical evidence for a role for Cbl-mediated PI3K signaling in the altered osteoblast phenotype induced by Twist haploinsufficiency in SCS. PMID:17003487

  17. Mixed Lineage Kinase Phosphorylates Transcription Factor E47 and Inhibits TrkB Expression to Link Neuronal Death and Survival Pathways*

    PubMed Central

    Pedraza, Neus; Rafel, Marta; Navarro, Isis; Encinas, Mario; Aldea, Martí; Gallego, Carme

    2009-01-01

    E47 is a basic helix-loop-helix transcription factor involved in neuronal differentiation and survival. We had previously shown that the basic helix-loop-helix protein E47 binds to E-box sequences within the promoter of the TrkB gene and activates its transcription. Proper expression of the TrkB receptor plays a key role in development and function of the vertebrate nervous system, and altered levels of TrkB have been associated with important human diseases. Here we show that E47 interacts with MLK2, a mixed lineage kinase (MLK) involved in JNK-mediated activation of programmed cell death. MLK2 enhances phosphorylation of the AD2 activation domain of E47 in vivo in a JNK-independent manner and phosphorylates in vitro defined serine and threonine residues within a loop-helix structure of AD2 that also contains a putative MLK docking site. Although these residues are essential for MLK2-mediated inactivation of E47, inhibition of MLKs by CEP11004 causes up-regulation of TrkB at a transcriptional level in cerebellar granule neurons and differentiating neuroblastoma cells. These findings allow us to propose a novel mechanism by which MLK regulates TrkB expression through phosphorylation of an activation domain of E47. This molecular link would explain why MLK inhibitors not only prevent activation of cell death processes but also enhance cell survival signaling as a key aspect of their neuroprotective potential. PMID:19801649

  18. Natural products induce a G protein-mediated calcium pathway activating p53 in cancer cells.

    PubMed

    van Ginkel, Paul R; Yan, Michael B; Bhattacharya, Saswati; Polans, Arthur S; Kenealey, Jason D

    2015-11-01

    Paclitaxel, etoposide, vincristine and doxorubicin are examples of natural products being used as chemotherapeutics but with adverse side effects that limit their therapeutic window. Natural products derived from plants and having low toxicity, such as quercetin, resveratrol, epigallocatechin gallate and piceatannol, have been shown to inhibit tumor cell growth both in vitro and in pre-clinical models of cancer, but their mechanisms of action have not been fully elucidated, thus restricting their use as prototypes for developing synthetic analogs with improved anti-cancer properties. We and others have demonstrated that one of the earliest and consistent events upon exposure of tumor cells to these less toxic natural products is a rise in cytoplasmic calcium, activating several pro-apoptotic pathways. We describe here a G protein/inositol 1,4,5-trisphosphate pathway (InsP3) in MDA-MB-231 human breast cancer cells that mediates between these less toxic natural products and the release of calcium from the endoplasmic reticulum. Further, we demonstrate that this elevation of intracellular calcium modulates p53 activity and the subsequent transcription of several pro-apoptotic genes encoding PIG8, CD95, PIDD, TP53INP, RRM2B, Noxa, p21 and PUMA. We conclude from our findings that less toxic natural products likely bind to a G protein coupled receptor that activates a G protein-mediated and calcium-dependent pathway resulting selectively in tumor cell death. PMID:26341291

  19. Rhizobium nod factor signaling. Evidence for a g protein-mediated transduction mechanism

    PubMed Central

    Pingret, JL; Journet, EP; Barker, DG

    1998-01-01

    Rhizobium nodulation (Nod) factors are lipochitooligosaccharide signals that elicit key symbiotic developmental responses in the host legume root. In this study, we have investigated Nod factor signal transduction in the Medicago root epidermis by using a pharmacological approach in conjunction with transgenic plants expressing the Nod factor-responsive reporter construct pMtENOD12-GUS. Evidence for the participation of heterotrimeric G proteins in Nod factor signaling has come from three complementary observations: (1) the amphiphilic peptides mastoparan and Mas7, known G protein agonists, are able to mimic Nod factor-induced epidermal MtENOD12 expression; (2) growth of plants in nodulation-inhibiting conditions (10 mM NH4NO3) leads to a dramatic reduction in both Nod factor- and mastoparan-elicited gene expression; and (3) bacterial pertussis toxin, a well-characterized G protein antagonist, blocks the activities of both the Nod factor and mastoparan. In addition, we have found that antagonists that interfere with phospholipase C activity (neomycin and U73122) and Ca2+ influx/release (EGTA, La3+, and ruthenium red) block Nod factor/mastoparan activity. Taken together, these results are consistent with a Nod factor signal transduction mechanism involving G protein mediation coupled to the activation of both phosphoinositide and Ca2+ second messenger pathways. PMID:9596628

  20. The IFITM proteins mediate cellular resistance to influenza A H1N1 virus, West Nile virus, and dengue virus

    E-print Network

    Huang, Ching-Tsan

    1 The IFITM proteins mediate cellular resistance to influenza A H1N1 virus, West Nile virus primary chicken fibroblast cells 10% FBS DMEM IftimDel+/- 13.5 Influenza A H1N1 virus A/PR/8/34PR IFITM3 influenza A H1N1 IFITM3 West Nile virus dengue virus IFITM viral-like particles

  1. Effect of Reactor Turbulence on the Binding-Protein-Mediated Aspartate Transport System in Thin Wastewater Biofilms

    PubMed Central

    Eighmy, T. Taylor; Bishop, P. L.

    1985-01-01

    This research documents an effect of reactor turbulence on the ability of gram-negative wastewater biofilm bacteria to actively transport l-aspartate via a binding-protein-mediated transport system. Biofilms which were not preadapted to turbulence and which possessed two separate and distinct aspartate transport systems (systems 1 and 2) were subjected to a turbulent flow condition in a hydrodynamically defined closed-loop reactor system. A shear stress treatment of 3.1 N · m?2 for 10 min at a turbulent Reynolds number (Re = 11,297) inactivated the low-affinity, high-capacity binding-protein-mediated transport system (system 2) and resolved the high-affinity, low-capacity membrane-bound proton symport system (system 1). The Kt and Vmax values for the resolved system were statistically similar to Kt and Vmax values for system 1 when system 2 was inactivated either by osmotic shock or arsenate, two treatments which are known to inactivate binding-protein-mediated transport systems. We hypothesize that shear stress disrupts system 2 by deforming the outer membranes of the firmly adhered gram-negative bacteria. PMID:16346830

  2. Lipid transfer protein-mediated resistance to a trichothecene mycotoxin – Novel players in FHB resistance

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Lipid transfer proteins are a class of basic cysteine rich proteins characterized by an eight cysteine motif backbone with intrinsic antimicrobial activities against bacterial and fungal pathogens. Previously, we identified two type IV nonspecific lipid transfer protein (nsLTP) genes (LTP4.4 and LTP...

  3. Radiation Basics

    MedlinePLUS

    EPA United States Environmental Protection Agency Search Search Radiation Protection Share Facebook Twitter Google+ Pinterest Contact Us ... are here: EPA Home » Radiation Protection » Radiation Basics Radiation Basics Radiation is energy. It can come from ...

  4. Id transcriptional regulators in adipogenesis and adipose tissue metabolism

    PubMed Central

    Patil, Mallikarjun; Sharma, Bal Krishan; Satyanarayana, Ande

    2014-01-01

    Id proteins (Id1-Id4) are helix-loop-helix (HLH) transcriptional regulators that lack a basic DNA binding domain. They act as negative regulators of basic helixloop-helix (bHLH) transcription factors by forming heterodimers and inhibit their DNA binding and transcriptional activity. Id proteins are implicated in the regulation of various cellular mechanisms such as cell proliferation, cellular differentiation, cell fate determination, angiogenesis and tumorigenesis. A handful of recent studies also disclosed that Id proteins have critical functions in adipocyte differentiation and adipose tissue metabolism. Here, we reviewed the progress made thus far in understanding the specific functions of Id proteins in adipose tissue differentiation and metabolism. In addition to reviewing the known mechanisms of action, we also discuss possible additional mechanisms in which Id proteins might participate in regulating adipogenic and metabolic pathways. PMID:24896358

  5. Citrus tristeza virus p23: a unique protein mediating key virus-host interactions.

    PubMed

    Flores, Ricardo; Ruiz-Ruiz, Susana; Soler, Nuria; Sánchez-Navarro, Jesús; Fagoaga, Carmen; López, Carmelo; Navarro, Luis; Moreno, Pedro; Peña, Leandro

    2013-01-01

    The large RNA genome of Citrus tristeza virus (CTV; ca. 20 kb) contains 12 open reading frames, with the 3'-terminal one corresponding to a protein of 209 amino acids (p23) that is expressed from an abundant subgenomic RNA. p23, an RNA-binding protein with a putative zinc-finger domain and some basic motifs, is unique to CTV because no homologs have been found in other closteroviruses, including the type species of the genus Beet yellows virus (despite both viruses having many homologous genes). Consequently, p23 might have evolved for the specific interaction of CTV with its citrus hosts. From a functional perspective p23 has been involved in many roles: (i) regulation of the asymmetrical accumulation of CTV RNA strands, (ii) induction of the seedling yellows syndrome in sour orange and grapefruit, (iii) intracellular suppression of RNA silencing, (iv) elicitation of CTV-like symptoms when expressed ectopically as a transgene in several Citrus spp., and (v) enhancement of systemic infection (and virus accumulation) in sour orange and CTV release from the phloem in p23-expressing transgenic sweet and sour orange. Moreover, transformation of Mexican lime with intron-hairpin constructs designed for the co-inactivation of p23 and the two other CTV silencing suppressors results in complete resistance against the homologous virus. From a cellular point of view, recent data indicate that p23 accumulates preferentially in the nucleolus, being the first closterovirus protein with such a subcellular localization, as well as in plasmodesmata. These major accumulation sites most likely determine some of the functional roles of p23. PMID:23653624

  6. BASIC Programming.

    ERIC Educational Resources Information Center

    Jennings, Carol Ann

    Designed for use by both secondary- and postsecondary-level business teachers, this curriculum guide consists of 10 units of instructional materials dealing with Beginners All-Purpose Symbol Instruction Code (BASIC) programing. Topics of the individual lessons are numbering BASIC programs and using the PRINT, END, and REM statements; system…

  7. Basic Warehousing.

    ERIC Educational Resources Information Center

    Marine Corps Inst., Washington, DC.

    Developed as part of the Marine Corps Institute (MCI) correspondence training program, this course on basic warehousing is designed to provide Marines with Military Occupation Speciality 3051 in the rank of private through corporal with instruction in those basic principles, methods, and procedures that can be applied to any warehousing or storage…

  8. Sme4 coiled-coil protein mediates synaptonemal complex assembly, recombinosome relocalization, and spindle pole body morphogenesis

    PubMed Central

    Espagne, Eric; Vasnier, Christelle; Storlazzi, Aurora; Kleckner, Nancy E.; Silar, Philippe; Zickler, Denise; Malagnac, Fabienne

    2011-01-01

    We identify a large coiled-coil protein, Sme4/PaMe4, that is highly conserved among the large group of Sordariales and plays central roles in two temporally and functionally distinct aspects of the fungal sexual cycle: first as a component of the meiotic synaptonemal complex (SC) and then, after disappearing and reappearing, as a component of the spindle pole body (SPB). In both cases, the protein mediates spatial juxtaposition of two major structures: linkage of homolog axes through the SC and a change in the SPB from a planar to a bent conformation. Corresponding mutants exhibit defects, respectively, in SC and SPB morphogenesis, with downstream consequences for recombination and astral-microtubule nucleation plus postmeiotic nuclear migration. Sme4 is also required for reorganization of recombination complexes in which Rad51, Mer3, and Msh4 foci relocalize from an on-axis position to a between-axis (on-SC) position concomitant with SC installation. Because involved recombinosome foci represent total recombinational interactions, these dynamics are irrespective of their designation for maturation into cross-overs or noncross-overs. The defined dual roles for Sme4 in two different structures that function at distinct phases of the sexual cycle also provide more functional links and evolutionary dynamics among the nuclear envelope, SPB, and SC. PMID:21666097

  9. CRYPTOCHROME 1 is implicated in promoting R protein-mediated plant resistance to Pseudomonas syringae in Arabidopsis.

    PubMed

    Wu, Liang; Yang, Hong-Quan

    2010-05-01

    Plants have evolved complex mechanisms to defend themselves against pathogens. It has been shown that several defense responses are influenced by light, and the red/far-red light photoreceptor phytochromes (PHY) modulate plant defense responses in Arabidopsis. Blue light receptor cryptochromes (CRY) work together with PHY to regulate many light-controlled responses, including photomorphogenesis, floral induction, and entrainment of the circadian clock. We report here that the Arabidopsis blue light photoreceptor CRY1 positively regulates inducible resistance to Pseudomonas syringae under continuous light conditions. By challenging plants with P. syringae pv. tomato (Pst.) DC3000 carrying avrRpt2, we demonstrate that effector-triggered local resistance is down-regulated in the cry1 mutant, leading to more pathogen multiplication. In plants overexpressing CRY1 (CRY1-ovx), however, local resistance is significantly up-regulated. We also show that systemic acquired resistance (SAR) is positively regulated by CRY1, and that salicylic acid (SA)-induced pathogenesis-related gene PR-1 expression is reduced in the cry1 mutant, but enhanced in CRY1-ovx plants. However, our results indicate that CRY1 only modestly influences SA accumulation and has no effect on hypersensitive cell death. These results suggest that CRY1 may positively regulate R protein-mediated resistance to P. syringae with increased PR gene expression. PMID:20053798

  10. Flavonoids: biosynthesis, biological functions, and biotechnological applications

    PubMed Central

    Falcone Ferreyra, María L.; Rius, Sebastián P.; Casati, Paula

    2012-01-01

    Flavonoids are widely distributed secondary metabolites with different metabolic functions in plants. The elucidation of the biosynthetic pathways, as well as their regulation by MYB, basic helix-loop-helix (bHLH), and WD40-type transcription factors, has allowed metabolic engineering of plants through the manipulation of the different final products with valuable applications. The present review describes the regulation of flavonoid biosynthesis, as well as the biological functions of flavonoids in plants, such as in defense against UV-B radiation and pathogen infection, nodulation, and pollen fertility. In addition, we discuss different strategies and achievements through the genetic engineering of flavonoid biosynthesis with implication in the industry and the combinatorial biosynthesis in microorganisms by the reconstruction of the pathway to obtain high amounts of specific compounds. PMID:23060891

  11. Transcriptional Control of Early T and B Cell Developmental Choices

    PubMed Central

    Rothenberg, Ellen V.

    2014-01-01

    T and B cells share a common somatic gene rearrangement mechanism for assembling the genes that code for their antigen receptors and developmental pathways with many parallels. Shared usage of basic helix-loop-helix E proteins as transcriptional drivers underlies these common features. However, the transcription factor networks in which these E proteins are embedded are different both in membership and in architecture for T and B cell gene regulatory programs. These differences permit lineage commitment decisions to be made in different hierarchical orders. Furthermore, in a contrast to B-cell gene networks, the T-cell gene network architecture for effector differentiation is sufficiently modular so that E protein inputs can be removed. Complete “T-cell-like” effector differentiation can proceed without T-cell receptor rearrangement or selection when E proteins are neutralized, yielding natural killer and other innate lymphoid cells. PMID:24471430

  12. Unique CCT repeats mediate transcription of the TWIST1 gene in mesenchymal cell lines

    SciTech Connect

    Ohkuma, Mizue; Funato, Noriko; Higashihori, Norihisa; Murakami, Masanori; Ohyama, Kimie; Nakamura, Masataka . E-mail: naka.gene@cmn.tmd.ac.jp

    2007-01-26

    TWIST1, a basic helix-loop-helix transcription factor, plays critical roles in embryo development, cancer metastasis and mesenchymal progenitor differentiation. Little is known about transcriptional regulation of TWIST1 expression. Here we identified DNA sequences responsible for TWIST1 expression in mesenchymal lineage cell lines. Reporter assays with TWIST1 promoter mutants defined the -102 to -74 sequences that are essential for TWIST1 expression in human and mouse mesenchymal cell lines. Tandem repeats of CCT, but not putative CREB and NF-{kappa}B sites in the sequences substantially supported activity of the TWIST1 promoter. Electrophoretic mobility shift assay demonstrated that the DNA sequences with the CCT repeats formed complexes with nuclear factors, containing, at least, Sp1 and Sp3. These results suggest critical implication of the CCT repeats in association with Sp1 and Sp3 factors in sustaining expression of the TWIST1 gene in mesenchymal cells.

  13. Molecular mechanisms of epithelial–mesenchymal transition

    PubMed Central

    Lamouille, Samy; Xu, Jian; Derynck, Rik

    2014-01-01

    The transdifferentiation of epithelial cells into motile mesenchymal cells, a process known as epithelial–mesenchymal transition (EMT), is integral in development, wound healing and stem cell behaviour, and contributes pathologically to fibrosis and cancer progression. This switch in cell differentiation and behaviour is mediated by key transcription factors, including SNAIL, zinc-finger E-box-binding (ZEB) and basic helix-loop-helix transcription factors, the functions of which are finely regulated at the transcriptional, translational and post-translational levels. The reprogramming of gene expression during EMT, as well as non-transcriptional changes, are initiated and controlled by signalling pathways that respond to extracellular cues. Among these, transforming growth factor-? (TGF?) family signalling has a predominant role; however, the convergence of signalling pathways is essential for EMT. PMID:24556840

  14. A genomewide survey of bHLH transcription factors in the coral Acropora digitifera identifies three novel orthologous families, pearl, amber, and peridot.

    PubMed

    Gyoja, Fuki; Kawashima, Takeshi; Satoh, Nori

    2012-04-01

    Decoding the genome of the coral, Acropora digitifera, enabled us to characterize a nearly full set of 70 basic helix-loop-helix (bHLH) transcription factors in this organism. This number is comparable to 68 bHLH genes in the sea anemone, Nematostella vectensis, and larger than those in most other invertebrate metazoans. The 70 bHLH genes were assigned to 29 orthologous families previously reported. In addition, we identified three novel HLH orthologous families, which we designated pearl, amber, and peridot, increasing the number of orthologous families to 32. Pearl and amber orthologues were found in genomes and expressed sequenced tags (ESTs) of Mollusca and Annelida in addition to Cnidaria. Peridot orthologues were found in genomes and ESTs of Cephalochordata and Hemichordata in addition to Cnidaria. These three genes were likely lost in the clades of Drosophila melanogaster, Caenorhabditis elegans, and Homo sapiens during animal evolution. PMID:22419240

  15. A mutually assured destruction mechanism attenuates light signaling in Arabidopsis.

    PubMed

    Ni, Weimin; Xu, Shou-Ling; Tepperman, James M; Stanley, David J; Maltby, Dave A; Gross, John D; Burlingame, Alma L; Wang, Zhi-Yong; Quail, Peter H

    2014-06-01

    After light-induced nuclear translocation, phytochrome photoreceptors interact with and induce rapid phosphorylation and degradation of basic helix-loop-helix transcription factors, such as PHYTOCHROME-INTERACTING FACTOR 3 (PIF3), to regulate gene expression. Concomitantly, this interaction triggers feedback reduction of phytochrome B (phyB) levels. Light-induced phosphorylation of PIF3 is necessary for the degradation of both proteins. We report that this PIF3 phosphorylation induces, and is necessary for, recruitment of LRB [Light-Response Bric-a-Brack/Tramtrack/Broad (BTB)] E3 ubiquitin ligases to the PIF3-phyB complex. The recruited LRBs promote concurrent polyubiqutination and degradation of both PIF3 and phyB in vivo. These data reveal a linked signal-transmission and attenuation mechanism involving mutually assured destruction of the receptor and its immediate signaling partner. PMID:24904166

  16. Nuclear localized protein-1 (Nulp1) increases cell death of human osteosarcoma cells and binds the X-linked inhibitor of apoptosis protein

    SciTech Connect

    Steen, Hakan; Lindholm, Dan

    2008-02-08

    Nuclear localized protein-1 (Nulp1) is a recently identified gene expressed in mouse and human tissues particularly during embryonic development. Nulp1 belongs to the family of basic helix-loop-helix (bHLH) proteins that are important in development. The precise function of Nulp1 in cells is however not known. We observed that overexpression of Nulp1 induces a large increase in cell death of human osteosarcoma Saos2 cells with DNA fragmentation. In mouse N2A neuroblastoma cells Nulp1 affected cell proliferation and sensitized cells towards death induced by staurosporine. Staining using a novel antibody localized Nulp1 mainly to the cell nucleus and to some extent to the cytoplasm. Nulp1 binds the X-linked inhibitor of apoptosis protein (XIAP) and this interaction was increased during cell death. These results indicate that Nulp1 plays a role in cell death control and may influence tumor growth.

  17. The conserved WRPW motif of Hes6 mediates proteasomal degradation

    SciTech Connect

    Kang, Seon Ah; Seol, Jae Hong; Kim, Jaesang . E-mail: jkim1964@ewha.ac.kr

    2005-06-24

    Hes6 belongs to a subfamily of basic helix-loop-helix transcription factors that includes Drosophila Hairy and Enhancer of split genes. Like other members of the family, Hes6 features the WRPW motif which is consisted just of four amino acids at its C-terminus. Here, we show that WRPW motif deletion mutant protein is substantially stabilized in comparison to the full length protein and that the enhanced stability is due to its resistance to proteasomal degradation. The WRPW motif also appears to be sufficient for acceleration of proteolysis as its fusion to two heterologous proteins, the green fluorescent protein (GFP) of Aequoria victoria and Gal4 DNA binding domain of Saccharomyces cerevisiae, significantly destabilized the proteins. These findings demonstrate a novel function of this conserved motif as a degradation signal and raise the possibility of utilizing it for controlling the level of ectopically expressed gene products.

  18. TCF12 Microdeletion in a 72-year-old Woman with Intellectual Disability

    PubMed Central

    Piard, Juliette; Rozé, Virginie; Czorny, Alain; Lenoir, Marion; Valduga, Mylène; Fenwick, Aimée L; Wilkie, Andrew O M; Maldergem, Lionel Van

    2015-01-01

    Heterozygous mutations in TCF12 were recently identified as an important cause of craniosynostosis. In the original series, 14% of patients with a mutation in TCF12 had significant developmental delay or learning disability. We report on the first case of TCF12 microdeletion, detected by array-comparative genomic hybridization, in a 72-year-old patient presenting with intellectual deficiency and dysmorphism. Multiplex ligation-dependent probe amplification analysis indicated that exon 19, encoding the functionally important basic helix-loop-helix domain, was included in the deleted segment in addition to exon 20. We postulate that the TCF12 microdeletion is responsible for this patient's intellectual deficiency and facial phenotype. © 2015 The Authors. American Journal of Medical Genetics Part A Published by Wiley Periodicals, Inc. PMID:25871887

  19. Proprioceptor pathway development is dependent on Math1

    NASA Technical Reports Server (NTRS)

    Bermingham, N. A.; Hassan, B. A.; Wang, V. Y.; Fernandez, M.; Banfi, S.; Bellen, H. J.; Fritzsch, B.; Zoghbi, H. Y.

    2001-01-01

    The proprioceptive system provides continuous positional information on the limbs and body to the thalamus, cortex, pontine nucleus, and cerebellum. We showed previously that the basic helix-loop-helix transcription factor Math1 is essential for the development of certain components of the proprioceptive pathway, including inner-ear hair cells, cerebellar granule neurons, and the pontine nuclei. Here, we demonstrate that Math1 null embryos lack the D1 interneurons and that these interneurons give rise to a subset of proprioceptor interneurons and the spinocerebellar and cuneocerebellar tracts. We also identify three downstream genes of Math1 (Lh2A, Lh2B, and Barhl1) and establish that Math1 governs the development of multiple components of the proprioceptive pathway.

  20. Research progress of the bHLH transcription factors involved in genic male sterility in plants.

    PubMed

    Yongming, Liu; Ling, Zhang; Jianyu, Zhou; Moju, Cao

    2015-12-01

    Male sterility exists widely in the spermatophytes. It contributes to the study of plant reproductive development and can be used as an effective tool for hybrid seed production in heterosis utilization. Therefore, the study on male sterility is of great value in both theory and application. As one of the largest transcription factor families in plants, basic helix-loop-helix proteins (bHLHs) play a crucial role in regulating plant growth and development. This paper introduces the mechanism of bHLH regulating stamen development in several important model plants. Furthermore, we discuss the molecular mechanisms of genic male sterility resulting from bHLH dysfunction to provide references for crop breeding and theoretical studies. PMID:26704944

  1. SARS Basics

    MedlinePLUS

    ... Isolation and Quarantine Fact Sheet References and Resources SARS Basics Fact Sheet Language: English Español (Spanish) Format: ... 3 pages] SARS [3 pages] SARS [3 pages] SARS? Severe acute respiratory syndrome (SARS) is a viral ...

  2. Basic Finance

    NASA Technical Reports Server (NTRS)

    Vittek, J. F.

    1972-01-01

    A discussion of the basic measures of corporate financial strength, and the sources of the information is reported. Considered are: balance sheet, income statement, funds and cash flow, and financial ratios.

  3. The Basics

    ERIC Educational Resources Information Center

    Indrisano, Roselmina; And Others

    1976-01-01

    These articles are presented as an aide in teaching basic subjects. This issue examines reading diagnosis, food preservation, prime numbers, electromagnets, acting out in language arts, self-directed spelling activities, and resources for environmental education. (Editor/RK)

  4. Asthma Basics

    MedlinePLUS

    ... Concussions: What to Know Pregnant? What to Expect Asthma Basics KidsHealth > Parents > Diseases & Conditions > Lungs & Respiratory System > ... Induced Asthma Allergy-Triggered Asthma Asthma Categories About Asthma Asthma is a common lung condition in kids ...

  5. Npas4 Is Activated by Melatonin, and Drives the Clock Gene Cry1 in the Ovine Pars Tuberalis

    PubMed Central

    West, A.; Dupré, S.M.; Yu, L.; Paton, I.R.; Miedzinska, K.; McNeilly, A.S.; Davis, J.R.E.

    2013-01-01

    Seasonal mammals integrate changes in the duration of nocturnal melatonin secretion to drive annual physiologic cycles. Melatonin receptors within the proximal pituitary region, the pars tuberalis (PT), are essential in regulating seasonal neuroendocrine responses. In the ovine PT, melatonin is known to influence acute changes in transcriptional dynamics coupled to the onset (dusk) and offset (dawn) of melatonin secretion, leading to a potential interval-timing mechanism capable of decoding changes in day length (photoperiod). Melatonin offset at dawn is linked to cAMP accumulation, which directly induces transcription of the clock gene Per1. The rise of melatonin at dusk induces a separate and distinct cohort, including the clock-regulated genes Cry1 and Nampt, but little is known of the up-stream mechanisms involved. Here, we used next-generation sequencing of the ovine PT transcriptome at melatonin onset and identified Npas4 as a rapidly induced basic helix-loop-helix Per-Arnt-Sim domain transcription factor. In vivo we show nuclear localization of NPAS4 protein in presumptive melatonin target cells of the PT (?-glycoprotein hormone-expressing cells), whereas in situ hybridization studies identified acute and transient expression in the PT of Npas4 in response to melatonin. In vitro, NPAS4 forms functional dimers with basic helix loop helix-PAS domain cofactors aryl hydrocarbon receptor nuclear translocator (ARNT), ARNT2, and ARNTL, transactivating both Cry1 and Nampt ovine promoter reporters. Using a combination of 5?-deletions and site-directed mutagenesis, we show NPAS4-ARNT transactivation to be codependent upon two conserved central midline elements within the Cry1 promoter. Our data thus reveal NPAS4 as a candidate immediate early-response gene in the ovine PT, driving molecular responses to melatonin. PMID:23598442

  6. Characterization of msim, a murine homologue of the Drosophila sim transcription factor

    SciTech Connect

    Moffett, P.; Reece, M.; Pelletier, J.

    1996-07-01

    Mutations in the Drosophila single-minded (sim) gene result in loss of precursor cells that give rise to midline cells of the embryonic central nervous system. During the course of an exon-trapping strategy aimed at identifying transcripts that contribute to the etiology and pathophysiology of Down syndrome, we identified a human exon from the Down syndrome, we identified a human exon from the Down syndrome critical region showing significantly homology to the Drosophila sim gene. Using a cross-hybridization approach, we have isolated a murine homolog of Drosophila sim gene, which we designated msim. Nucleotide and predicted amino acid sequence analyses of msim cDNA clones indicate the this gene encodes a member of the basic-helix-loop-helix class of transcription factors. The murine and Drosophila proteins share 88% residues within the basic-helix-loop helix domain, with an overall homology of 92%. In addition, the N-terminal domain of MSIM contains two PAS dimerization motifs also featured in the Drosophila sim gene product, as well as a small number of other transcription factors. Northern blot analysis of adult murine tissues revealed that the msim gene produces a single mRNA species of {approximately}4 kb expressed in a small number of tissues, with the highest levels in the kidneys and lower levels present in skeletal muscle, lung, testis, brain, and heart. In situ hybridization experiments demonstrate that msim is also expressed in early fetal development in the central nervous system and in cartilage primordia. The characteristics of the msim gene are consistent with its putative function as a transcriptional regulator. 51 refs., 6 figs., 1 tab.

  7. The genetics of rhizosheath size in a multiparent mapping population of wheat

    PubMed Central

    Delhaize, Emmanuel; Rathjen, Tina M.; Cavanagh, Colin R.

    2015-01-01

    Rhizosheaths comprise soil that adheres to plant roots and, in some species, are indicative of root hair length. In this study, the genetics of rhizosheath size in wheat was investigated by screening the progeny of multiparent advanced generation intercrosses (MAGIC). Two MAGIC populations were screened for rhizosheath size using a high throughput method. One MAGIC population was developed from intercrosses between four parents (4-way) and the other from intercrosses between eight parents (8-way). Transgressive segregation for rhizosheath size was observed in both the 4-way and 8-way MAGIC populations. A quantitative trait loci (QTL) analysis of the 4-way population identified six major loci located on chromosomes 2B, 4D, 5A, 5B, 6A, and 7A together accounting for 42% of the variation in rhizosheath size. Rhizosheath size was strongly correlated with root hair length and was robust across different soil types in the absence of chemical constraints. Rhizosheath size in the MAGIC populations was a reliable surrogate for root hair length and, therefore, the QTL identified probably control root hair elongation. Members of the basic helix-loop-helix family of transcription factors have previously been identified to regulate root hair length in Arabidopsis and rice. Since several wheat members of the basic helix-loop-helix family of genes are located within or near the QTL, these genes are candidates for controlling the long root hair trait. The QTL for rhizosheath size identified in this study provides the opportunity to implement marker-assisted selection to increase root hair length for improved phosphate acquisition in wheat. PMID:25969556

  8. Alcohol oxidase protein mediated in-situ synthesized and stabilized gold nanoparticles for developing amperometric alcohol biosensor.

    PubMed

    Chinnadayyala, Somasekhar R; Santhosh, Mallesh; Singh, Naveen K; Goswami, Pranab

    2015-07-15

    A simple one step method for the alcohol oxidases (AOx) protein mediated synthesis of gold nano-particles (AuNPs) in alkaline (pH 8.5) condition with simultaneous stabilization of the nanoparticles on the AOx protein surface under native environment has been developed. The formation of the AOx conjugated AuNPs was confirmed by advanced analytical and spectroscopic techniques. The significant increase in zeta potential (?) value of -57mV for the synthesized AOx-AuNPs conjugate from the AOx (pI 4.5) protein (?, -30mV) implied good stability of the in-situ synthesized nano-conjugate. The AOx-AuNPs conjugate showed steady stability in alkaline (upto pH 8.5) and NaCl (up to 10(-1)M) solutions. The efficiency (Kcat/Km) of the AuNP conjugated AOx was increased by 18% from the free enzyme confirming the activating role of the surface stabilized AuNPs for the enzyme. The AuNPs-AOx conjugate was encapsulated with polyaniline (PANI) synthesized by oxidative polymerization of aniline using H2O2 generated in-situ from the AOx catalysed oxidation of alcohol. The PANI encapsulated AuNPs-AOx assembly was stabilized on a glassy carbon electrode (GCE) by chitosan-Nafion mixture and then utilized the fabricated bioelectrode for detection of alcohol amperometrically using H2O2 as redox indicator at +0.6V. The constructed biosensor showed high operational stability (6.3% loss after 25 measurements), wide linear detection range of 10µM-4.7mM (R(2)=0.9731), high sensitivity of 68.3±0.35µAmM(-1) and low detection limit of 7±0.027µM for ethanol. The fabricated bioelectrode was successfully used for the selective determination of alcohol in beverage samples. PMID:25725464

  9. DOS basics

    SciTech Connect

    O`Connor, P.

    1994-09-01

    DOS is an acronym for Disk Operating System. It is actually a set of programs that allows you to control your personal computer. DOS offers the capabilities to create and manage files; organize and maintain information placed on disks; use application programs such as WordPerfect, Lotus 123, Excel, Windows, etc. In addition, DOS provides the basic utilities needed to copy files from one area to another, delete files and list files. The latest version of DOS also offers more advanced features that include hard disk compression and memory management. Basic DOS commands are discussed.

  10. Protein mediated membrane adhesion

    NASA Astrophysics Data System (ADS)

    Carlson, Andreas; Mahadevan, L.

    2015-05-01

    Adhesion in the context of mechanical attachment, signaling, and movement in cellular dynamics is mediated by the kinetic interactions between membrane-embedded proteins in an aqueous environment. Here, we present a minimal theoretical framework for the dynamics of membrane adhesion that accounts for the kinetics of protein binding, the elastic deformation of the membrane, and the hydrodynamics of squeeze flow in the membrane gap. We analyze the resulting equations using scaling estimates to characterize the spatiotemporal features of the adhesive patterning and corroborate them using numerical simulations. In addition to characterizing aspects of cellular dynamics, our results might also be applicable to a range of phenomena in physical chemistry and materials science where flow, deformation, and kinetics are coupled to each other in slender geometries.

  11. Ethanol Basics

    SciTech Connect

    2015-01-30

    Ethanol is a widely-used, domestically-produced renewable fuel made from corn and other plant materials. More than 96% of gasoline sold in the United States contains ethanol. Learn more about this alternative fuel in the Ethanol Basics Fact Sheet, produced by the U.S. Department of Energy's Clean Cities program.

  12. Basic cosmology

    E-print Network

    Ll. Bel

    2014-03-22

    Basic cosmology describes the universe as a Robertson-Walker model filled with black-body radiation and no barionic matter, and as observational data it uses only the value of the speed of light, the Hubble and deceleration parameters and the black-body temperature at the present epoch. It predicts the value of the next new parameter in the Hubble law.

  13. Basic Horticulture.

    ERIC Educational Resources Information Center

    Geer, Barbra Farabough

    This learning packet contains teaching suggestions and student learning materials for a course in basic horticulture aimed at preparing students for employment in a number of horticulture areas. The packet includes nine sections and twenty instructional units. Following the standard format established for Oklahoma vocational education materials in…

  14. Body Basics

    MedlinePLUS

    ... more about how the body works, what basic human anatomy is, and what happens when parts of the body don't function properly. Blood Bones, Muscles, and Joints Brain and Nervous System Digestive System Endocrine System Eyes Female Reproductive System Heart and Circulatory System Immune ...

  15. Basic Science.

    ERIC Educational Resources Information Center

    Mercer County Community Coll., Trenton, NJ.

    Instructional materials are provided for a course that covers basic concepts of physics and chemistry. Designed for use in a workplace literacy project developed by Mercer County Community College (New Jersey) and its partners, the course describes applications of these concepts to real-life situations, with an emphasis on applications of…

  16. Basic Backwardness.

    ERIC Educational Resources Information Center

    Weingartner, Charles

    This paper argues that the "back to basics" movement is regressive and that regression is the characteristic mode of fear-ridden personalities. It is argued that many people in American society today have lost their ability to laugh and do not have the sense of humor which is crucial to a healthy mental state. Such topics as necrophilia, mental…

  17. Basic Skills--Basic Business.

    ERIC Educational Resources Information Center

    Conference Board of Canada, Ottawa (Ontario).

    The experience of eight prominent Canadian business organizations was examined in terms of how basic skills deficits are identified in their work force, the impact of those deficiencies on organizational competitiveness, and why corporate programs are developed in response to the issue. Some of the key findings were as follows: (1) employee…

  18. Mussel inspired protein-mediated surface functionalization of electrospun nanofibers for pH-responsive drug delivery

    PubMed Central

    Jiang, Jiang; Xie, Jingwei; Ma, Bing; Bartlett, David E.; Xu, An; Wang, Chi-Hwa

    2014-01-01

    pH-responsive drug delivery systems could mediate drug releasing rate by changing pH values at specific time as per the pathophysiological need of the disease. Herein, we demonstrated a mussel inspired protein polydopamine coating can tune the loading and releasing rate of charged molecules from electrospun poly (?-caprolactone) (PCL) nanofibers in solutions with different pH values. In vitro release profiles showed that the positive charged molecules released significantly faster in acidic than those in neutral and basic environments within the same incubation time. The results of fluorescein diacetate staining and 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assays showed the viability of cancer cells after treatment with doxorubicin released media at different pH values qualitatively and quantitatively, indicating the media contained doxorubicin which was released in solutions at low pH values could kill significantly higher number of cells than that released in solutions at high pH values. Together, the pH-responsive drug delivery systems based on polydopamine-coated PCL nanofibers could have potential applications in oral delivery of anticancer drugs for treating gastric cancer and vaginal delivery of anti-viral drugs or anti-inflammatory drugs, which could raise their efficacy, deliver them to the specific target, and minimize their toxic side effects. PMID:24287161

  19. Stem Cell Basics

    MedlinePLUS

    ... General Information Stem Cell Basics Stem Cell Basics Stem Cell Information General Information Clinical Trials Funding Information Current Research Policy Glossary Site Map Stem Cell Basics This primer on stem cells is ...

  20. Gq protein mediates UVB-induced cyclooxygenase-2 expression by stimulating HB-EGF secretion from HaCaT human keratinocytes

    SciTech Connect

    Seo, MiRan; Juhnn, Yong-Sung

    2010-03-05

    Ultraviolet (UV) radiation induces cyclooxygenase-2 expression to produce cellular responses including aging and carcinogenesis in skin. We hypothesised that heterotrimeric G proteins mediate UV-induced COX-2 expression by stimulating secretion of soluble HB-EGF (sHB-EGF). In this study, we aimed to elucidate the role and underlying mechanism of the {alpha} subunit of Gq protein (G{alpha}q) in UVB-induced HB-EGF secretion and COX-2 induction. We found that expression of constitutively active G{alpha}q (G{alpha}qQL) augmented UVB-induced HB-EGF secretion, which was abolished by knockdown of G{alpha}q with shRNA in HaCaT human keratinocytes. G{alpha}q was found to mediate the UVB-induced HB-EGF secretion by sequential activation of phospholipase C (PLC), protein kinase C{delta} (PKC{delta}), and matrix metaloprotease-2 (MMP-2). Moreover, G{alpha}qQL mediated UVB-induced COX-2 expression in an HB-EGF-, EGFR-, and p38-dependent manner. From these results, we concluded that G{alpha}q mediates UV-induced COX-2 expression through activation of EGFR by HB-EGF, of which ectodomain shedding was stimulated through sequential activation of PLC, PKC{delta} and MMP-2 in HaCaT cells.

  1. Basics of Photometry Photometry: Basic Questions

    E-print Network

    Masci, Frank

    Basics of Photometry #12;Photometry: Basic Questions · How do you identify objects in your image type of object you're studying? #12;#12;#12;Topics 1. General Considerations 2. Stellar Photometry 3. Galaxy Photometry #12;I: General Considerations 1. Garbage in, garbage out... 2. Object Detection 3

  2. Role of the EF-hand-like Motif in the 14-3-3 Protein-mediated Activation of Yeast Neutral Trehalase Nth1*

    PubMed Central

    Kopecka, Miroslava; Kosek, Dalibor; Kukacka, Zdenek; Rezabkova, Lenka; Man, Petr; Novak, Petr; Obsil, Tomas; Obsilova, Veronika

    2014-01-01

    Trehalases hydrolyze the non-reducing disaccharide trehalose amassed by cells as a universal protectant and storage carbohydrate. Recently, it has been shown that the activity of neutral trehalase Nth1 from Saccharomyces cerevisiae is mediated by the 14-3-3 protein binding that modulates the structure of both the catalytic domain and the region containing the EF-hand-like motif, whose role in the activation of Nth1 is unclear. In this work, the structure of the Nth1·14-3-3 complex and the importance of the EF-hand-like motif were investigated using site-directed mutagenesis, hydrogen/deuterium exchange coupled to mass spectrometry, chemical cross-linking, and small angle x-ray scattering. The low resolution structural views of Nth1 alone and the Nth1·14-3-3 complex show that the 14-3-3 protein binding induces a significant structural rearrangement of the whole Nth1 molecule. The EF-hand-like motif-containing region forms a separate domain that interacts with both the 14-3-3 protein and the catalytic trehalase domain. The structural integrity of the EF-hand like motif is essential for the 14-3-3 protein-mediated activation of Nth1, and calcium binding, although not required for the activation, facilitates this process by affecting its structure. Our data suggest that the EF-hand like motif-containing domain functions as the intermediary through which the 14-3-3 protein modulates the function of the catalytic domain of Nth1. PMID:24713696

  3. Hybrids of the bHLH and bZIP Protein Motifs Display Different DNA-Binding Activities In Vivo vs. In Vitro

    PubMed Central

    Chow, Hiu-Kwan; Xu, Jing; Shahravan, S. Hesam; De Jong, Antonia T.; Chen, Gang; Shin, Jumi A.

    2008-01-01

    Minimalist hybrids comprising the DNA-binding domain of bHLH/PAS (basic-helix-loop-helix/Per-Arnt-Sim) protein Arnt fused to the leucine zipper (LZ) dimerization domain from bZIP (basic region-leucine zipper) protein C/EBP were designed to bind the E-box DNA site, CACGTG, targeted by bHLHZ (basic-helix-loop-helix-zipper) proteins Myc and Max, as well as the Arnt homodimer. The bHLHZ-like structure of ArntbHLH-C/EBP comprises the Arnt bHLH domain fused to the C/EBP LZ: i.e. swap of the 330 aa PAS domain for the 29 aa LZ. In the yeast one-hybrid assay (Y1H), transcriptional activation from the E-box was strong by ArntbHLH-C/EBP, and undetectable for the truncated ArntbHLH (PAS removed), as detected via readout from the HIS3 and lacZ reporters. In contrast, fluorescence anisotropy titrations showed affinities for the E-box with ArntbHLH-C/EBP and ArntbHLH comparable to other transcription factors (Kd 148.9 nM and 40.2 nM, respectively), but only under select conditions that maintained folded protein. Although in vivo yeast results and in vitro spectroscopic studies for ArntbHLH-C/EBP targeting the E-box correlate well, the same does not hold for ArntbHLH. As circular dichroism confirms that ArntbHLH-C/EBP is a much more strongly ?-helical structure than ArntbHLH, we conclude that the nonfunctional ArntbHLH in the Y1H must be due to misfolding, leading to the false negative that this protein is incapable of targeting the E-box. Many experiments, including protein design and selections from large libraries, depend on protein domains remaining well-behaved in the nonnative experimental environment, especially small motifs like the bHLH (60–70 aa). Interestingly, a short helical LZ can serve as a folding- and/or solubility-enhancing tag, an important device given the focus of current research on exploration of vast networks of biomolecular interactions. PMID:18949049

  4. CSF myelin basic protein

    MedlinePLUS

    CSF myelin basic protein is a test to measure the level of myelin basic protein (MBP) in the cerebrospinal fluid (CSF). The CSF ... less than 4 ng/mL of myelin basic protein in the CSF. Note: ng/mL = nanogram per ...

  5. Relocating Basic Writing

    ERIC Educational Resources Information Center

    Horner, Bruce

    2011-01-01

    I frame the continuing value of basic writing as part of a long tradition in composition studies challenging dominant beliefs about literacy and language abilities, and I link basic writing to emerging--e.g."translingual"--approaches to language. I identify basic writing as vital to the field of composition in its rejection of simplistic notions…

  6. Exponentiation: A New Basic?

    ERIC Educational Resources Information Center

    Davis, Brent

    2015-01-01

    For centuries, the basic operations of school mathematics have been identified as addition, subtraction, multiplication, and division. Notably, these operations are "basic," not because they are foundational to mathematics knowledge, but because they were vital to a newly industrialized and market-driven economy several hundred years…

  7. INTRODUCTION TO BASIC SERVLET

    E-print Network

    Ricci, Francesco

    Chapter CHAPTER 2: A FAST INTRODUCTION TO BASIC SERVLET PROGRAMMING Topics in This Chapter · The advantages of servlets over competing technologies · The basic servlet structure and life cycle · Servlet · The servlet equivalent of the standard CGI variables · Cookies in servlets · Session tracking Taken from More

  8. Basic Science Training Program.

    ERIC Educational Resources Information Center

    Brummel, Clete

    These six learning modules were developed for Lake Michigan College's Basic Science Training Program, a workshop to develop good study skills while reviewing basic science. The first module, which was designed to provide students with the necessary skills to study efficiently, covers the following topics: time management; an overview of a study…

  9. Basic Electronics I.

    ERIC Educational Resources Information Center

    Robertson, L. Paul

    Designed for use in basic electronics programs, this curriculum guide is comprised of twenty-nine units of instruction in five major content areas: Orientation, Basic Principles of Electricity/Electronics, Fundamentals of Direct Current, Fundamentals of Alternating Current, and Applying for a Job. Each instructional unit includes some or all of…

  10. Fluency with Basic Addition

    ERIC Educational Resources Information Center

    Garza-Kling, Gina

    2011-01-01

    Traditionally, learning basic facts has focused on rote memorization of isolated facts, typically through the use of flash cards, repeated drilling, and timed testing. However, as many experienced teachers have seen, "drill alone does not develop mastery of single-digit combinations." In contrast, a fluency approach to learning basic addition…

  11. Romanian Basic Course.

    ERIC Educational Resources Information Center

    Defense Language Inst., Washington, DC.

    The "Romanian Basic Course," consisting of 89 lesson units in eight volumes, is designed to train native English language speakers to Level 3 proficiency in comprehension, speaking, reading, and writing Romanian (based on a 1-5 scale in which Level 5 is native speaker proficiency). Volume 1, which introduces basic sentences in dialog form with…

  12. BASIC: Updating a Familiar Language.

    ERIC Educational Resources Information Center

    Eyman, David H.

    1988-01-01

    Discusses reasons for learning to program in BASIC, various versions of BASIC, BASIC compilers, and adherence to proposed standards. Brief reviews of six BASIC software packages are included. (12 references) (MES)

  13. Association Between Seed Dormancy and Pericarp Color Is Controlled by a Pleiotropic Gene That Regulates Abscisic Acid and Flavonoid Synthesis in Weedy Red Rice

    PubMed Central

    Gu, Xing-You; Foley, Michael E.; Horvath, David P.; Anderson, James V.; Feng, Jiuhuan; Zhang, Lihua; Mowry, Chase R.; Ye, Heng; Suttle, Jeffrey C.; Kadowaki, Koh-ichi; Chen, Zongxiang

    2011-01-01

    Seed dormancy has been associated with red grain color in cereal crops for a century. The association was linked to qSD7-1/qPC7, a cluster of quantitative trait loci for seed dormancy/pericarp color in weedy red rice. This research delimited qSD7-1/qPC7 to the Os07g11020 or Rc locus encoding a basic helix-loop-helix family transcription factor by intragenic recombinants and provided unambiguous evidence that the association arises from pleiotropy. The pleiotropic gene expressed in early developing seeds promoted expression of key genes for biosynthesis of abscisic acid (ABA), resulting in an increase in accumulation of the dormancy-inducing hormone; activated a conserved network of eight genes for flavonoid biosynthesis to produce the pigments in the lower epidermal cells of the pericarp tissue; and enhanced seed weight. Thus, the pleiotropic locus most likely controls the dormancy and pigment traits by regulating ABA and flavonoid biosynthetic pathways, respectively. The dormancy effect could be eliminated by a heat treatment, but could not be completely overcome by gibberellic acid or physical removal of the seed maternal tissues. The dormancy-enhancing alleles differentiated into two groups basically associated with tropical and temperate ecotypes of weedy rice. Of the pleiotropic effects, seed dormancy could contribute most to the weed adaptation. Pleiotropy prevents the use of the dormancy gene to improve resistance of white pericarp cultivars against pre-harvest sprouting through conventional breeding approaches. PMID:21954164

  14. DEC1 negatively regulates AMPK activity via LKB1.

    PubMed

    Sato, Fuyuki; Muragaki, Yasuteru; Zhang, Yanping

    2015-11-27

    Basic helix-loop-helix (bHLH) transcription factor DEC1 (bHLHE40/Stra13/Sharp2) is one of the clock genes that show a circadian rhythm in various tissues. AMP-activated protein kinase (AMPK) activity plays important roles in the metabolic process and in cell death induced by glucose depletion. Recent reports have shown that AMPK activity exhibited a circadian rhythm. However, little is known regarding the regulatory mechanisms involved in the circadian rhythm of AMPK activity. The aim of this study is to investigate whether there is a direct correlation between DEC1 expression and AMPK activity. DEC1 protein and AMPK activity showed a circadian rhythm in the mouse liver with different peak levels. Knocking down DEC1 expression increased AMPK activity, whereas overexpression of DEC1 decreased it. Overexpressing the DEC1 basic mutants had little effect on the AMPK activity. DEC1 bound to the E-box of the LKB1 promoter, decreased LKB1 activity and total protein levels. There was an inverse relationship between DEC1 expression and AMPK activity. Our results suggest that DEC1 negatively regulates AMPK activity via LKB1. PMID:26498531

  15. Protective Effect of Electroacupuncture on Neural Myelin Sheaths is Mediated via Promotion of Oligodendrocyte Proliferation and Inhibition of Oligodendrocyte Death After Compressed Spinal Cord Injury.

    PubMed

    Huang, Siqin; Tang, Chenglin; Sun, Shanquan; Cao, Wenfu; Qi, Wei; Xu, Jin; Huang, Juan; Lu, Weitian; Liu, Qian; Gong, Biao; Zhang, Yi; Jiang, Jin

    2015-12-01

    Electroacupuncture (EA) has been used worldwide to treat demyelinating diseases, but its therapeutic mechanism is poorly understood. In this study, a custom-designed model of compressed spinal cord injury (CSCI) was used to induce demyelination. Zusanli (ST36) and Taixi (KI3) acupoints of adult rats were stimulated by EA to demonstrate its protective effect. At 14 days after EA, both locomotor skills and ultrastructural features of myelin sheath were significantly improved. Phenotypes of proliferating cells were identified by double immunolabeling of 5-ethynyl-2'-deoxyuridine with antibodies to cell markers: NG2 [oligodendrocyte precursor cell (OPC) marker], 2',3'-cyclic-nucleotide 3'-phosphodiesterase (CNPase) (oligodendrocyte marker), and glial fibrillary acidic protein (GFAP) (astrocyte marker). EA enhanced the proliferation of OPCs and CNPase, as well as the differentiation of OPCs by promoting Olig2 (the basic helix-loop-helix protein) and attenuating Id2 (the inhibitor of DNA binding 2). EA could also improve myelin basic protein (MBP) and protect existing oligodendrocytes from apoptosis by inhibiting caspase-12 (a representative of endoplasmic reticulum stress) and cytochrome c (an apoptotic factor and hallmark of mitochondria). Therefore, our results indicate that the protective effect of EA on neural myelin sheaths is mediated via promotion of oligodendrocyte proliferation and inhibition of oligodendrocyte death after CSCI. PMID:25465241

  16. Developmental expression of COE across the Metazoa supports a conserved role in neuronal cell-type specification and mesodermal development.

    PubMed

    Jackson, Daniel J; Meyer, Néva P; Seaver, Elaine; Pang, Kevin; McDougall, Carmel; Moy, Vanessa N; Gordon, Kacy; Degnan, Bernard M; Martindale, Mark Q; Burke, Robert D; Peterson, Kevin J

    2010-12-01

    The transcription factor COE (collier/olfactory-1/early B cell factor) is an unusual basic helix-loop-helix transcription factor as it lacks a basic domain and is maintained as a single copy gene in the genomes of all currently analysed non-vertebrate Metazoan genomes. Given the unique features of the COE gene, its proposed ancestral role in the specification of chemosensory neurons and the wealth of functional data from vertebrates and Drosophila, the evolutionary history of the COE gene can be readily investigated. We have examined the ways in which COE expression has diversified among the Metazoa by analysing its expression from representatives of four disparate invertebrate phyla: Ctenophora (Mnemiopsis leidyi); Mollusca (Haliotis asinina); Annelida (Capitella teleta and Chaetopterus) and Echinodermata (Strongylocentrotus purpuratus). In addition, we have studied COE function with knockdown experiments in S. purpuratus, which indicate that COE is likely to be involved in repressing serotonergic cell fate in the apical ganglion of dipleurula larvae. These analyses suggest that COE has played an important role in the evolution of ectodermally derived tissues (likely primarily nervous tissues) and mesodermally derived tissues. Our results provide a broad evolutionary foundation from which further studies aimed at the functional characterisation and evolution of COE can be investigated. PMID:21069538

  17. Basics of Insurance

    MedlinePLUS

    ... PARC) Contact Us About Us News Blog Events Facebook Twitter YouTube Instagram Donate Now Take Action Ways ... Navigating Insurance Choosing Coverage Basics of Insurance Share Facebook Twitter Email More options Print Share Facebook Twitter ...

  18. Wth Basic Art Materials

    ERIC Educational Resources Information Center

    Herberholz, Barbara

    2010-01-01

    In this article, the author presents a checklist of basic materials for two-dimensional activities that are necessary for an elementary-school art program. She also provides a few tips on how to use them.

  19. Video Screen Capture Basics

    ERIC Educational Resources Information Center

    Dunbar, Laura

    2014-01-01

    This article is an introduction to video screen capture. Basic information of two software programs, QuickTime for Mac and BlueBerry Flashback Express for PC, are also discussed. Practical applications for video screen capture are given.

  20. Brain Basics: Understanding Sleep

    MedlinePLUS

    ... Find People About NINDS Request free mailed brochure Brain Basics: Understanding Sleep Request free mailed brochure Do ... our daily lives. We now know that our brains are very active during sleep. Moreover, sleep affects ...

  1. Basic Cancer Research Program

    Cancer.gov

    Investigators in the Basic Cancer Research Program focus their research on biological variations across racially and ethnically diverse populations that either naturally, or in conjunction with environmental exposures, may lead to differences in cancer

  2. Health Insurance Basics

    MedlinePLUS

    ... Your Best Self Smart Snacking Losing Weight Safely Health Insurance Basics KidsHealth > Teens > Body > Getting Medical Care > Health ... thought advanced calculus was confusing. What Exactly Is Health Insurance? Health insurance is a plan that people buy ...

  3. Basic-deformed thermostatistics

    E-print Network

    A. Lavagno; A. M. Scarfone; P. Narayana Swamy

    2007-06-04

    Starting from the basic-exponential, a q-deformed version of the exponential function established in the framework of the basic-hypergeometric series, we present a possible formulation of a generalized statistical mechanics. In a q-nonuniform lattice we introduce the basic-entropy related to the basic-exponential by means of a q-variational principle. Remarkably, this distribution exhibits a natural cut-off in the energy spectrum. This fact, already encountered in other formulations of generalized statistical mechanics, is expected to be relevant to the applications of the theory to those systems governed by long-range interactions. By employing the q-calculus, it is shown that the standard thermodynamic functional relationships are preserved, mimicking, in this way, the mathematical structure of the ordinary thermostatistics which is recovered in the q=1 limit.

  4. High-temperature inhibition of biosynthesis and transportation of anthocyanins results in the poor red coloration in red-fleshed Actinidia chinensis.

    PubMed

    Man, Yu-Ping; Wang, Yan-Chang; Li, Zuo-Zhou; Jiang, Zheng-Wang; Yang, Hong-Li; Gong, Jun-Jie; He, Shi-Song; Wu, Shi-Quan; Yang, Zuo-Quan; Zheng, Jing; Wang, Zhong-Yan

    2015-04-01

    In plants, the role of anthocyanins trafficking in response to high temperature has been rarely studied, and therefore poorly understood. Red-fleshed kiwifruit has stimulated the world kiwifruit industry owing to its appealing color. However, fruit in warmer climates have been found to have poor flesh coloration, and the factors responsible for this response remain elusive. Partial correlation and regression analysis confirmed that accumulative temperatures above 25 °C (T25) was one of the dominant factors inhibiting anthocyanin accumulation in red-fleshed Actinidia chinensis, 'Hongyang'. Expression of structural genes, AcMRP and AcMYB1 in inner pericarp sampled from the two high altitudes (low temperature area), was notably higher than the low altitude (high temperature area) during fruit coloration. AcMYB1 and structural genes coordinate expression supported the MYB-bHLH (basic helix-loop-helix)-WD40 regulatory complex mediated downregulation of anthocyanin biosynthesis induced by high temperatures in kiwifruit. Moreover, cytological observations using the light and transmission electronic microscopy showed that there were a series of anthocyanic vacuolar inclusion (AVI)-like structures involved in their vacuolization process and dissolution of the pigmented bodies inside cells of fruit inner pericarp. Anthocyanin transport was inhibited by high temperature via retardation of vacuolization or reduction in AIV-like structure formation. Our findings strongly suggested that complex multimechanisms influenced the effects of high temperature on red-fleshed kiwifruit coloration. PMID:25143057

  5. Pbx acts with Hand2 in early myocardial differentiation

    PubMed Central

    Maves, Lisa; Tyler, Ashlee; Moens, Cecilia B.; Tapscott, Stephen J.

    2009-01-01

    Transcription factors of the basic helix-loop-helix (bHLH) family are critical regulators of muscle cell differentiation. For example, Myod drives skeletal muscle differentiation, and Hand2 potentiates cardiac muscle differentiation. Understanding how these bHLH factors regulate distinct transcriptional targets in a temporally and spatially controlled manner is critical for understanding their activity in cellular differentiation. We previously showed that Pbx homeodomain proteins modulate the activity of Myod to promote the differentiation of fast-twitch skeletal muscle. Here, we test the hypothesis that Pbx proteins are also necessary for cardiac muscle differentiation through interacting with Hand2. We show that Pbx proteins are required for the activation of cardiac muscle differentiation in zebrafish embryos. Loss of Pbx activity leads to delay of myocardial differentiation and subsequent defective cardiac morphogenesis, similar to reduced Hand2 activity. Genetic interaction experiments support the hypothesis that Pbx proteins modulate the activity of Hand2 in myocardial differentiation. Furthermore, we show that Pbx proteins directly bind the promoter of the myocardial differentiation gene myl7 in vitro, supporting a direct role for Pbx proteins in promoting cardiac muscle differentiation. Our findings demonstrate new roles for Pbx proteins in vertebrate cardiac development and also provide new insight into connections between the transcriptional regulation of skeletal and cardiac muscle differentiation programs. PMID:19607825

  6. Identification of residues in the N-terminal PAS domains important for dimerization of Arnt and AhR

    PubMed Central

    Hao, Nan; Whitelaw, Murray L.; Shearwin, Keith E.; Dodd, Ian B.; Chapman-Smith, Anne

    2011-01-01

    The basic helix–loop–helix (bHLH).PAS dimeric transcription factors have crucial roles in development, stress response, oxygen homeostasis and neurogenesis. Their target gene specificity depends in part on partner protein choices, where dimerization with common partner Aryl hydrocarbon receptor nuclear translocator (Arnt) is an essential step towards forming active, DNA binding complexes. Using a new bacterial two-hybrid system that selects for loss of protein interactions, we have identified 22 amino acids in the N-terminal PAS domain of Arnt that are involved in heterodimerization with aryl hydrocarbon receptor (AhR). Of these, Arnt E163 and Arnt S190 were selective for the AhR/Arnt interaction, since mutations at these positions had little effect on Arnt dimerization with other bHLH.PAS partners, while substitution of Arnt D217 affected the interaction with both AhR and hypoxia inducible factor-1? but not with single minded 1 and 2 or neuronal PAS4. Arnt uses the same face of the N-terminal PAS domain for homo- and heterodimerization and mutational analysis of AhR demonstrated that the equivalent region is used by AhR when dimerizing with Arnt. These interfaces differ from the PAS ?-scaffold surfaces used for dimerization between the C-terminal PAS domains of hypoxia inducible factor-2? and Arnt, commonly used for PAS domain interactions. PMID:21245039

  7. AhR/Arnt:XRE interaction: Turning false negatives into true positives in the modified yeast one-hybrid assay

    PubMed Central

    Chen, Gang; Shin, Jumi A.

    2009-01-01

    Given the frequent occurrence of false negatives in yeast genetic assays, it is both interesting and practical to address the possible mechanisms of false negatives and, more important, to turn false negatives into true positives. We recently developed a modified yeast one-hybrid system (MY1H) useful for investigation of simultaneous protein–protein and protein:DNA interactions in vivo. We coexpressed the basic helix–loop–helix/Per-Arnt-Sim (bHLH/PAS) domains of aryl hydrocarbon receptor (AhR) and aryl hydrocarbon receptor nuclear translocator (Arnt)—namely NAhR and NArnt, respectively—which are known to form heterodimers and bind the cognate xenobiotic response element (XRE) sequence both in vitro and in vivo, as a positive control in the study of XRE-binding proteins in the MY1H system. However, we observed negative results, that is, no positive signal detected from binding of the NAhR/NArnt heterodimer and XRE site. We demonstrate that by increasing the copy number of XRE sites integrated into the yeast genome and using double GAL4 activation domains, the NAhR/NArnt heterodimer forms and specifically binds the cognate XRE sequence, an interaction that is now clearly detectable in the MY1H system. This methodology may be helpful in troubleshooting and correcting false negatives that arise from unproductive transcription in yeast genetic assays. PMID:18722998

  8. Genetic Factors for Enhancement of Nicotine Levels in Cultivated Tobacco.

    PubMed

    Wang, Bingwu; Lewis, Ramsey S; Shi, Junli; Song, Zhongbang; Gao, Yulong; Li, Wenzheng; Chen, Hongxia; Qu, Rongda

    2015-01-01

    Nicotine has practical applications relating to smoking cessation devices and alternative nicotine products. Genetic manipulation for increasing nicotine content in cultivated tobacco (Nicotiana tabacum L.) may be of value for industrial purposes, including the possibility of enhancing the efficiency of nicotine extraction. Biotechnological approaches have been evaluated in connection with this objective, but field-based results are few. Here, we report characterization of two genes encoding basic-helix-loop-helix (bHLH) transcription factors (TFs), NtMYC2a and NtMYC2b from tobacco. Overexpression of NtMYC2a increased leaf nicotine levels in T1 transgenic lines approximately 2.3-fold in greenhouse-grown plants of tobacco cultivar 'NC 95'. Subsequent field testing of T2 and T3 generations of transgenic NtMYC2a overexpression lines showed nicotine concentrations were 76% and 58% higher than control lines, respectively. These results demonstrated that the increased nicotine trait was stably inherited to the T2 and T3 generations, indicating the important role that NtMYC2a plays in regulating nicotine accumulation in N. tabacum and the great potential of NtMYC2a overexpression in tobacco plants for industrial nicotine production. Collected data in this study also indicated a negative feedback inhibition of nicotine biosynthesis. Further enhancement of nicotine accumulation in tobacco leaf may require modification of the processes of nicotine transport and deposition. PMID:26626731

  9. The Transcriptional Repressor MYB2 Regulates Both Spatial and Temporal Patterns of Proanthocyandin and Anthocyanin Pigmentation in Medicago truncatula[OPEN

    PubMed Central

    2015-01-01

    Accumulation of anthocyanins and proanthocyanidins (PAs) is limited to specific cell types and developmental stages, but little is known about how antagonistically acting transcriptional regulators work together to determine temporal and spatial patterning of pigmentation at the cellular level, especially for PAs. Here, we characterize MYB2, a transcriptional repressor regulating both anthocyanin and PA biosynthesis in the model legume Medicago truncatula. MYB2 was strongly upregulated by MYB5, a major regulator of PA biosynthesis in M. truncatula and a component of MYB-basic helix loop helix-WD40 (MBW) activator complexes. Overexpression of MYB2 abolished anthocyanin and PA accumulation in M. truncatula hairy roots and Arabidopsis thaliana seeds, respectively. Anthocyanin deposition was expanded in myb2 mutant seedlings and flowers accompanied by increased anthocyanin content. PA mainly accumulated in the epidermal layer derived from the outer integument in the M. truncatula seed coat, starting from the hilum area. The area of PA accumulation and ANTHOCYANIDIN REDUCTASE expression was expanded into the seed body at the early stage of seed development in the myb2 mutant. Genetic, biochemical, and cell biological evidence suggests that MYB2 functions as part of a multidimensional regulatory network to define the temporal and spatial pattern of anthocyanin and PA accumulation linked to developmental processes. PMID:26410301

  10. Arabidopsis FAMA Controls the Final Proliferation/Differentiation Switch during Stomatal Development[W][OA

    PubMed Central

    Ohashi-Ito, Kyoko; Bergmann, Dominique C.

    2006-01-01

    Coordination between cell proliferation and differentiation is essential to create organized and functional tissues. Arabidopsis thaliana stomata are created through a stereotyped series of symmetric and asymmetric cell divisions whose frequency and orientation are informed by cell–cell interactions. Receptor-like proteins and a mitogen-activated protein kinase kinase kinase were previously identified as negative regulators of stomatal development; here, we present the characterization of a bona fide positive regulator. FAMA is a putative basic helix-loop-helix transcription factor whose activity is required to promote differentiation of stomatal guard cells and to halt proliferative divisions in their immediate precursors. Ectopic FAMA expression is also sufficient to confer stomatal character. Physical and genetic interaction studies combined with functional characterization of FAMA domains suggest that stomatal development relies on regulatory complexes distinct from those used to specify other plant epidermal cells. FAMA behavior provides insights into the control of differentiation in cells produced through the activity of self-renewing populations. PMID:17088607

  11. Evidence for direct activation of an anthocyanin promoter by the maize C1 protein and comparison of DNA binding by related Myb domain proteins.

    PubMed Central

    Sainz, M B; Grotewold, E; Chandler, V L

    1997-01-01

    The enzyme-encoding genes of two classes of maize flavonoid pigments, anthocyanins and phlobaphenes, are differentially regulated by distinct transcription factors. Anthocyanin biosynthetic gene activation requires the Myb domain C1 protein and the basic helix-loop-helix B or R proteins. In the phlobaphene pathway, a subset of C1-regulated genes, including a1, are activated by the Myb domain P protein independently of B/R. We show sequence-specific binding to the a1 promoter by C1 in the absence of B. Activation is decreased by mutations in the C1 DNA binding domain or in a1 sequences bound by C1, providing direct evidence for activation of the anthocyanin biosynthetic genes by C1. The two C1 binding sites in the a1 promoter are also bound by P. One site is bound with higher affinity by P relative to C1, whereas the other site is bound with similar lower affinity by both proteins. Interestingly, either site is sufficient for C1 plus B/R or P activation in vivo, demonstrating that differences in DNA binding affinities between P and C1 are insufficient to explain the differential requirement for B. Results of DNA binding site-selection experiments suggest that C1 has a broader DNA binding specificity than does P, which may help C1 to activate a more diverse set of promoters. PMID:9144964

  12. Evidence for direct activation of an anthocyanin promoter by the maize C1 protein and comparison of DNA binding by related Myb domain proteins.

    PubMed

    Sainz, M B; Grotewold, E; Chandler, V L

    1997-04-01

    The enzyme-encoding genes of two classes of maize flavonoid pigments, anthocyanins and phlobaphenes, are differentially regulated by distinct transcription factors. Anthocyanin biosynthetic gene activation requires the Myb domain C1 protein and the basic helix-loop-helix B or R proteins. In the phlobaphene pathway, a subset of C1-regulated genes, including a1, are activated by the Myb domain P protein independently of B/R. We show sequence-specific binding to the a1 promoter by C1 in the absence of B. Activation is decreased by mutations in the C1 DNA binding domain or in a1 sequences bound by C1, providing direct evidence for activation of the anthocyanin biosynthetic genes by C1. The two C1 binding sites in the a1 promoter are also bound by P. One site is bound with higher affinity by P relative to C1, whereas the other site is bound with similar lower affinity by both proteins. Interestingly, either site is sufficient for C1 plus B/R or P activation in vivo, demonstrating that differences in DNA binding affinities between P and C1 are insufficient to explain the differential requirement for B. Results of DNA binding site-selection experiments suggest that C1 has a broader DNA binding specificity than does P, which may help C1 to activate a more diverse set of promoters. PMID:9144964

  13. The members of bHLH transcription factor superfamily are required for female reproduction in the red flour beetle, Tribolium castaneum

    PubMed Central

    Bitra, Kavita; Palli, Subba R.

    2010-01-01

    Proteins containing the basic Helix-Loop-Helix (bHLH) domain function as transcription factors and play important roles during the development of various metazoans including insects, nematodes and vertebrates. Insect genomes contain more than 50 bHLH transcription factors, but the function of only a few of these proteins in regulation of female reproduction is known. Using RNA interference, we have tested knock-down in the expression of genes coding for bHLH transcription factors in newly emerged adult females to determine their function in regulation of female reproduction in the red flour beetle, Tribolium castaneum. Knock-down in the expression of genes coding for four bHLH transcription factors (TcSRC, TcSim1, TcAsh and TcDaughterless) has caused mortality in the female beetles. In addition, knocking-down the expression of 16 bHLH genes has affected oogenesis and knock-down in the expression of 13 genes has affected embryogenesis. Two genes TcSide1 and TcSpineless are required for both oogenesis and embryogenesis. Thus, the data reported here showed that 31 bHLH transcription factors are required for female survival, reproduction and embryogenesis. PMID:20223247

  14. Program Specificity for Ptf1a in Pancreas versus Neural Tube Development Correlates with Distinct Collaborating Cofactors and Chromatin Accessibility

    PubMed Central

    Meredith, David M.; Borromeo, Mark D.; Deering, Tye G.; Casey, Bradford H.; Savage, Trisha K.; Mayer, Paul R.; Hoang, Chinh; Tung, Kuang-Chi; Kumar, Manonmani; Shen, Chengcheng; Swift, Galvin H.

    2013-01-01

    The lineage-specific basic helix-loop-helix transcription factor Ptf1a is a critical driver for development of both the pancreas and nervous system. How one transcription factor controls diverse programs of gene expression is a fundamental question in developmental biology. To uncover molecular strategies for the program-specific functions of Ptf1a, we identified bound genomic regions in vivo during development of both tissues. Most regions bound by Ptf1a are specific to each tissue, lie near genes needed for proper formation of each tissue, and coincide with regions of open chromatin. The specificity of Ptf1a binding is encoded in the DNA surrounding the Ptf1a-bound sites, because these regions are sufficient to direct tissue-restricted reporter expression in transgenic mice. Fox and Sox factors were identified as potential lineage-specific modifiers of Ptf1a binding, since binding motifs for these factors are enriched in Ptf1a-bound regions in pancreas and neural tube, respectively. Of the Fox factors expressed during pancreatic development, Foxa2 plays a major role. Indeed, Ptf1a and Foxa2 colocalize in embryonic pancreatic chromatin and can act synergistically in cell transfection assays. Together, these findings indicate that lineage-specific chromatin landscapes likely constrain the DNA binding of Ptf1a, and they identify Fox and Sox gene families as part of this process. PMID:23754747

  15. Crystal structure of the heterodimeric CLOCK:BMAL1 transcriptional activator complex.

    PubMed

    Huang, Nian; Chelliah, Yogarany; Shan, Yongli; Taylor, Clinton A; Yoo, Seung-Hee; Partch, Carrie; Green, Carla B; Zhang, Hong; Takahashi, Joseph S

    2012-07-13

    The circadian clock in mammals is driven by an autoregulatory transcriptional feedback mechanism that takes approximately 24 hours to complete. A key component of this mechanism is a heterodimeric transcriptional activator consisting of two basic helix-loop-helix PER-ARNT-SIM (bHLH-PAS) domain protein subunits, CLOCK and BMAL1. Here, we report the crystal structure of a complex containing the mouse CLOCK:BMAL1 bHLH-PAS domains at 2.3 Å resolution. The structure reveals an unusual asymmetric heterodimer with the three domains in each of the two subunits--bHLH, PAS-A, and PAS-B--tightly intertwined and involved in dimerization interactions, resulting in three distinct protein interfaces. Mutations that perturb the observed heterodimer interfaces affect the stability and activity of the CLOCK:BMAL1 complex as well as the periodicity of the circadian oscillator. The structure of the CLOCK:BMAL1 complex is a starting point for understanding at an atomic level the mechanism driving the mammalian circadian clock. PMID:22653727

  16. Unequally redundant RCD1 and SRO1 mediate stress and developmental responses and interact with transcription factors.

    PubMed

    Jaspers, Pinja; Blomster, Tiina; Brosché, Mikael; Salojärvi, Jarkko; Ahlfors, Reetta; Vainonen, Julia P; Reddy, Ramesha A; Immink, Richard; Angenent, Gerco; Turck, Franziska; Overmyer, Kirk; Kangasjärvi, Jaakko

    2009-10-01

    RADICAL-INDUCED CELL DEATH1 (RCD1) is an important regulator of stress and hormonal and developmental responses in Arabidopsis thaliana. Together with its closest homolog, SIMILAR TO RCD-ONE1 (SRO1), it is the only Arabidopsis protein containing the WWE domain, which is known to mediate protein-protein interactions in other organisms. Additionally, these two proteins contain the core catalytic region of poly-ADP-ribose transferases and a conserved C-terminal domain. Tissue and subcellular localization data indicate that RCD1 and SRO1 have partially overlapping functions in plant development. In contrast mutant data indicate that rcd1 has defects in plant development, whereas sro1 displays normal development. However, the rcd1 sro1 double mutant has severe growth defects, indicating that RCD1 and SRO1 exemplify an important genetic principle - unequal genetic redundancy. A large pair-wise interaction test against the REGIA transcription factor collection revealed that RCD1 interacts with a large number of transcription factors belonging to several protein families, such as AP2/ERF, NAC and basic helix-loop-helix (bHLH), and that SRO1 interacts with a smaller subset of these. Full genome array analysis indicated that in many cases targets of these transcription factors have altered expression in the rcd1 but not the sro1 mutant. Taken together RCD1 and SRO1 are required for proper plant development. PMID:19548978

  17. Artificial ligand binding within the HIF2[alpha] PAS-B domain of the HIF2 transcription factor

    SciTech Connect

    Scheuermann, Thomas H.; Tomchick, Diana R.; Machius, Mischa; Guo, Yan; Bruick, Richard K.; Gardner, Kevin H.

    2009-05-12

    The hypoxia-inducible factor (HIF) basic helix-loop-helix Per-aryl hydrocarbon receptor nuclear translocator (ARNT)-Sim (bHLH-PAS) transcription factors are master regulators of the conserved molecular mechanism by which metazoans sense and respond to reductions in local oxygen concentrations. In humans, HIF is critically important for the sustained growth and metastasis of solid tumors. Here, we describe crystal structures of the heterodimer formed by the C-terminal PAS domains from the HIF2{alpha} and ARNT subunits of the HIF2 transcription factor, both in the absence and presence of an artificial ligand. Unexpectedly, the HIF2{alpha} PAS-B domain contains a large internal cavity that accommodates ligands identified from a small-molecule screen. Binding one of these ligands to HIF2{alpha} PAS-B modulates the affinity of the HIF2{alpha}:ARNT PAS-B heterodimer in vitro. Given the essential role of PAS domains in forming active HIF heterodimers, these results suggest a presently uncharacterized ligand-mediated mechanism for regulating HIF2 activity in endogenous and clinical settings.

  18. Immunohistochemical Study of Expression of Sohlh1 and Sohlh2 in Normal Adult Human Tissues

    PubMed Central

    Zhang, Xiaoli; Liu, Ruihua; Su, Zhongxue; Zhang, Yuecun; Zhang, Wenfang; Liu, Xinyu; Wang, Fuwu; Guo, Yuji; Li, Chuangang; Hao, Jing

    2015-01-01

    The expression pattern of Sohlh1 (spermatogenesis and oogenesis specific basic helix-loop-helix 1) and Sohlh2 in mice has been reported in previous studies. Sohlh1 and Sohlh2 are specifically expressed in spermatogonia, prespermatogonia in male mice and oocytes of primordial and primary follicles in female mice. In this report, we studied the expression pattern of Sohlh1 and Sohlh2 in human adult tissues. Immunohistochemical staining of Sohlh1 and Sohlh2 was performed in 5 samples of normal ovaries and testes, respectively. The results revealed that Sohlh genes are not only expressed in oocytes and spermatogonia, but also in granular cells, theca cells, Sertoli cells and Leydig cells, and in smooth muscles of blood vessel walls. To further investigate the expression of Sohlh genes in other adult human tissues, we collected representative normal adult tissues developed from three embryonic germ layers. Compared with the expression in mice, Sohlhs exhibited a much more extensive expression pattern in human tissues. Sohlhs were detected in testis, ovary and epithelia developed from embryonic endoderm, ectoderm and tissues developed from embryonic mesoderm. Sohlh signals were found in spermatogonia, Sertoli cells and also Leydig cells in testis, while in ovary, the expression was mainly in oocytes of primordial and primary follicles, granular cells and theca cells of secondary follicles. Compared with Sohlh2, the expression of Sohlh1 was stronger and more extensive. Our study explored the expression of Sohlh genes in human tissues and might provide insights for functional studies of Sohlh genes. PMID:26375665

  19. Twist-related protein 1-mediated regulation of mesenchymal change contributes to the migration and invasion of cervical cancer cells

    PubMed Central

    WANG, DANQING; LI, QINGLI; LI, KEMIN; XIAO, PING; YIN, RUTIE

    2015-01-01

    Twist-related protein 1 (Twist1), is a class II basic helix-loop-helix transcription factor, which has been demonstrated to be a major regulator of epithelial-mesenchymal transition (EMT), and therefore is involved in promoting carcinoma metastasis. Previous studies have demonstrated that Twist1 expression is upregulated in cervical cancer cases with poor clinical outcomes. However, the mechanisms that mediate the role of Twist1 in cervical cancer metastasis are poorly understood. To the best of our knowledge, the present study provides the first evidence that the downregulation of Twist1 by short hairpin RNA lentivirus (LV-shRNA) resulted in the inhibition of invasion and migration of cervical cancer cells. Furthermore, the present study presents evidence that reducing Twist1 expression prevents cervical cancer cells from undergoing EMT. The expression of the epithelial cell marker, E-cadherin, was elevated; and the expression levels of mesenchymal cell markers [fibronectin, vimentin, matrix metalloproteinase-9 (MMP-9) and MMP-2] were reduced in the LV-sh-Twist1 group in cervical cells. Collectively, these findings indicate that Twist1-mediated modulation of EMT is important in the invasion and migration of cervical cells, and also indicates the potential therapeutic importance of strategies involving the inactivation of Twist1-mediated mesenchymal changes in cervical cancer. PMID:26722297

  20. Virulence Factors of Geminivirus Interact with MYC2 to Subvert Plant Resistance and Promote Vector Performance[C][W

    PubMed Central

    Li, Ran; Weldegergis, Berhane T.; Li, Jie; Jung, Choonkyun; Qu, Jing; Sun, Yanwei; Qian, Hongmei; Tee, ChuanSia; van Loon, Joop J.A.; Dicke, Marcel; Chua, Nam-Hai; Liu, Shu-Sheng

    2014-01-01

    A pathogen may cause infected plants to promote the performance of its transmitting vector, which accelerates the spread of the pathogen. This positive effect of a pathogen on its vector via their shared host plant is termed indirect mutualism. For example, terpene biosynthesis is suppressed in begomovirus-infected plants, leading to reduced plant resistance and enhanced performance of the whiteflies (Bemisia tabaci) that transmit these viruses. Although begomovirus-whitefly mutualism has been known, the underlying mechanism is still elusive. Here, we identified ?C1 of Tomato yellow leaf curl China virus, a monopartite begomovirus, as the viral genetic factor that suppresses plant terpene biosynthesis. ?C1 directly interacts with the basic helix-loop-helix transcription factor MYC2 to compromise the activation of MYC2-regulated terpene synthase genes, thereby reducing whitefly resistance. MYC2 associates with the bipartite begomoviral protein BV1, suggesting that MYC2 is an evolutionarily conserved target of begomoviruses for the suppression of terpene-based resistance and the promotion of vector performance. Our findings describe how this viral pathogen regulates host plant metabolism to establish mutualism with its insect vector. PMID:25490915

  1. An RNA Virus-Encoded Zinc-Finger Protein Acts as a Plant Transcription Factor and Induces a Regulator of Cell Size and Proliferation in Two Tobacco Species[C][W

    PubMed Central

    Lukhovitskaya, Nina I.; Solovieva, Anna D.; Boddeti, Santosh K.; Thaduri, Srinivas; Solovyev, Andrey G.; Savenkov, Eugene I.

    2013-01-01

    Plant viruses cause a variety of diseases in susceptible hosts. The disease symptoms often include leaf malformations and other developmental abnormalities, suggesting that viruses can affect plant development. However, little is known about the mechanisms underlying virus interference with plant morphogenesis. Here, we show that a C-4 type zinc-finger (ZF) protein, p12, encoded by a carlavirus (chrysanthemum virus B) can induce cell proliferation, which results in hyperplasia and severe leaf malformation. We demonstrate that the p12 protein activates expression of a regulator of cell size and proliferation, designated upp-L (upregulated by p12), which encodes a transcription factor of the basic/helix-loop-helix family sufficient to cause hyperplasia. The induction of upp-L requires translocation of the p12 protein into the nucleus and ZF-dependent specific interaction with the conserved regulatory region in the upp-L promoter. Our results establish the role of the p12 protein in modulation of host cell morphogenesis. It is likely that other members of the conserved C-4 type ZF family of viral proteins instigate reprogramming of plant development by mimicking eukaryotic transcriptional activators. PMID:23482855

  2. The homeodomain-containing gene Xdbx inhibits neuronal differentiation in the developing embryo.

    PubMed

    Gershon, A A; Rudnick, J; Kalam, L; Zimmerman, K

    2000-07-01

    The development of the vertebrate nervous system depends upon striking a balance between differentiating neurons and neural progenitors in the early embryo. Our findings suggest that the homeodomain-containing gene Xdbx regulates this balance by maintaining neural progenitor populations within specific regions of the neuroectoderm. In posterior regions of the Xenopus embryo, Xdbx is expressed in a bilaterally symmetric stripe that lies at the middle of the mediolateral axis of the neural plate. This stripe of Xdbx expression overlaps the expression domain of the proneural basic/helix-loop-helix-containing gene, Xash3, and is juxtaposed to the expression domains of Xenopus Neurogenin related 1 and N-tubulin, markers of early neurogenesis in the embryo. Xdbx overexpression inhibits neuronal differentiation in the embryo and when co-injected with Xash3, Xdbx inhibits the ability of Xash3 to induce ectopic neurogenesis. One role of Xdbx during normal development may therefore be to restrict spatially neuronal differentiation within the neural plate, possibly by altering the neuronal differentiation function of Xash3. PMID:10851138

  3. Tfe3 expression is closely associated to macrophage terminal differentiation of human hematopoietic myeloid precursors

    SciTech Connect

    Zanocco-Marani, Tommaso; Vignudelli, Tatiana; Gemelli, Claudia; Pirondi, Sara; Testa, Anna; Montanari, Monica; Parenti, Sandra; Tenedini, Elena; Grande, Alexis; Ferrari, Sergio . E-mail: sergio@unimo.it

    2006-12-10

    The MItf-Tfe family of basic helix-loop-helix leucine zipper (bHLH-Zip) transcription factors encodes four family members: MItf, Tfe3, TfeB and TfeC. In vitro, each protein of the family binds DNA in a homo- or heterodimeric form with other family members. Tfe3 is involved in chromosomal translocations recurrent in different tumors and it has been demonstrated, by in vivo studies, that it plays, redundantly with MItf, an important role in the process of osteoclast formation, in particular during the transition from mono-nucleated to multi-nucleated osteoclasts. Since mono-nucleated osteoclasts derive from macrophages we investigated whether Tfe3 might play a role upstream during hematopoietic differentiation. Here we show that Tfe3 is able to induce mono-macrophagic differentiation of U937 cells, in association with a decrease of cell proliferation and an increase of apoptosis. We also show that Tfe3 does not act physiologically during commitment of CD34+ hematopoietic stem cells (HSCs), since it is not able to direct HSCs toward a specific lineage as observed by clonogenic assay, but is a strong actor of terminal differentiation since it allows human primary myeloblasts' maturation toward the macrophage lineage.

  4. Inhibition of endothelial cell activation by bHLH protein E2-2 and its impairment of angiogenesis.

    PubMed

    Tanaka, Aya; Itoh, Fumiko; Nishiyama, Koichi; Takezawa, Toshiaki; Kurihara, Hiroki; Itoh, Susumu; Kato, Mitsuyasu

    2010-05-20

    E2-2 belongs to the basic helix-loop-helix (bHLH) family of transcription factors. E2-2 associates with inhibitor of DNA binding (Id) 1, which is involved in angiogenesis. In this paper, we demonstrate that E2-2 interacts with Id1 and provide evidence that this interaction potentiates angiogenesis. Mutational analysis revealed that the HLH domain of E2-2 is required for the interaction with Id1 and vice versa. In addition, Id1 interfered with E2-2-mediated effects on luciferase reporter activities. Interestingly, injection of E2-2-expressing adenoviruses into Matrigel plugs implanted under the skin blocked in vivo angiogenesis. In contrast, the injection of Id1-expressing adenoviruses rescued E2-2-mediated inhibition of in vivo angiogenic reaction. Consistent with the results of the Matrigel plug assay, E2-2 could inhibit endothelial cell (EC) migration, network formation, and proliferation. On the other hand, knockdown of E2-2 in ECs increased EC migration. The blockade of EC migration by E2-2 was relieved by exogenous expression of Id1. We also demonstrated that E2-2 can perturb VEGFR2 expression via inhibition of VEGFR2 promoter activity. This study suggests that E2-2 can maintain EC quiescence and that Id1 can counter this effect. PMID:20231428

  5. CD26-mediated regulation of periostin expression contributes to migration and invasion of malignant pleural mesothelioma cells

    SciTech Connect

    Komiya, Eriko; Ohnuma, Kei; Yamazaki, Hiroto; Hatano, Ryo; Iwata, Satoshi; Okamoto, Toshihiro; Dang, Nam H.; Morimoto, Chikao

    2014-05-16

    Highlights: • CD26-expressing MPM cells upregulate production of periostin. • The intracytoplasmic region of CD26 mediates the upregulation of periostin. • CD26 expression leads to nuclear translocation of Twist1 via phosphorylation of Src. • Secreted periostin enhances migration and invasion of MPM cells. - Abstract: Malignant pleural mesothelioma (MPM) is an aggressive malignancy arising from mesothelial lining of pleura. It is generally associated with a history of asbestos exposure and has a very poor prognosis, partly due to the lack of a precise understanding of the molecular mechanisms associated with its malignant behavior. In the present study, we expanded on our previous studies on the enhanced motility and increased CD26 expression in MPM cells, with a particular focus on integrin adhesion molecules. We found that expression of CD26 upregulates periostin secretion by MPM cells, leading to enhanced MPM cell migratory and invasive activity. Moreover, we showed that upregulation of periostin expression results from the nuclear translocation of the basic helix-loop-helix transcription factor Twist1, a process that is mediated by CD26-associated activation of Src phosphorylation. While providing new and profound insights into the molecular mechanisms involved in MPM biology, these findings may also lead to the development of novel therapeutic strategies for MPM.

  6. The Mouse Clock Locus: Sequence and Comparative Analysis of 204 Kb from Mouse Chromosome 5

    PubMed Central

    Wilsbacher, Lisa D.; Sangoram, Ashvin M.; Antoch, Marina P.; Takahashi, Joseph S.

    2000-01-01

    The Clock gene encodes a basic helix-loop-helix (bHLH)–PAS transcription factor that regulates circadian rhythms in mice. We previously cloned Clock in mouse and human using a battery of behavioral and molecular techniques, including shotgun sequencing of two bacterial artificial chromosome (BAC) clones. Here we report the finished sequence of a 204-kb region from mouse chromosome 5. This region contains the complete loci for the Clock and Tpardl (pFT27) genes, as well as the 3? partial locus of the Neuromedin U gene; sequence analysis also suggests the presence of two previously unidentified genes. In addition, we provide a comparative genomic sequence analysis with the syntenic region from human chromosome 4. Finally, a new BAC transgenic line indicates that the genomic region that is sufficient for rescue of the Clock mutant phenotype is no greater than 120 kb and tightly flanks the 3? end of the Clock gene. [The sequence data reported in this paper have been submitted to the GenBank data library under accession no. AF146793.] PMID:11116088

  7. The t(14;21)(q11.2;q22) chromosomal translocation associated with T-cell acute lymphoblastic leukemia activates the BHLHB1 gene

    PubMed Central

    Wang, Junjie; Jani-Sait, Sheila N.; Escalon, Enrique A.; Carroll, Andrew J.; de Jong, Pieter J.; Kirsch, Ilan R.; Aplan, Peter D.

    2000-01-01

    We have cloned the genomic breakpoints for a balanced t(14;21)(q11.2;q22) chromosomal translocation associated with T-cell acute lymphoblastic leukemia. Sequence analysis of the genomic breakpoints indicated that the translocation had been mediated by an illegitimate V(D)J recombination event that disrupted the T-cell receptor (TCR) ? locus and placed the TCR ? locus enhancer on the derivative 21 chromosome. We identified a previously unreported transcript, designated BHLHB1 (for basic domain, helix–loop–helix protein, class B, 1) that had been activated by the translocation. BHLHB1 mapped to the region of chromosome 21 that has been proposed to be responsible, at least in part, for the learning deficits seen in children with Down's syndrome. Although BHLHB1 expression normally is restricted to neural tissues, T-cell lymphoblasts with the t(14;21)(q11.2;q22) also expressed high levels of BHLHB1 mRNA. Expression of BHLHB1 dramatically inhibited E2A-mediated transcription activation in NIH 3T3 fibroblasts and Jurkat T cells. This observation suggests that BHLHB1, similar to SCL/TAL1, may exert a leukemogenic effect through a functional inactivation of E2A or related proteins. PMID:10737801

  8. Structure and Dimerization Properties of the Aryl Hydrocarbon Receptor PAS-A Domain

    PubMed Central

    Wu, Dalei; Potluri, Nalini; Kim, Youngchang

    2013-01-01

    The aryl hydrocarbon receptor (AHR) is a ligand-dependent transcription factor that binds to xenobiotics and responds by regulating the expression of gene programs required for detoxification and metabolism. AHR and its heterodimerization partner aryl hydrocarbon receptor nuclear translocator (ARNT) belong to the basic helix-loop-helix (bHLH)–PER-ARNT-SIM (PAS) family of transcription factors. Here we report the 2.55-?-resolution crystal structure of the mouse AHR PAS-A domain, which represents the first AHR-derived protein structure. The AHR PAS-A domain forms a helix-swapped homodimer in the crystal and also in solution. Through a detailed mutational analysis of all interface residues, we identified several hydrophobic residues that are important for AHR dimerization and function. Our crystallographic visualization of AHR PAS-A dimerization leads us to propose a mode of heterodimerization with ARNT that is supported by both biochemical and cell-based data. Our studies also highlight the residues of other mammalian bHLH-PAS proteins that are likely involved in their homo- or heterodimerization. PMID:24001774

  9. Neurogenin3 triggers beta-cell differentiation of retinoic acid-derived endoderm cells.

    PubMed Central

    Vetere, Amedeo; Marsich, Eleonora; Di Piazza, Matteo; Koncan, Raffaella; Micali, Fulvio; Paoletti, Sergio

    2003-01-01

    Neurogenin3 is a member of the basic helix-loop-helix ('bHLH') family of transcription factors. It plays a crucial role in the commitment of embryonic endoderm into the pancreatic differentiation programme. This factor is considered to act upstream of a cascade of other transcription factors, leading to the fully differentiated endocrine phenotype. Direct observation of the sequential activation of these factors starting from Neurogenin3 had never been demonstrated. By using retinoic acid-derived-endoderm F9 cells as a model, the present study indicates that the ectopic expression of Neurogenin3 is able to start the differentiation pathway of endocrine pancreas. Neurogenin3 triggers the expression of several pancreatic transcription factors following a well defined temporal activation sequence. By reverse transcriptase PCR, immunohistochemistry and RIA, it is shown that stable transfected cells are able to form embryod bodies that produce insulin in response to glucose stimulation. This is the first report of a differentiation event induced by the ectopic expression of a transcription factor in embryonic pluripotent stem cells. PMID:12529176

  10. Assignment of the human MAD and MXI1 genes to chromosomes 2p12-p13 and 10q24-q25

    SciTech Connect

    Shapiro, D.N.; Eagle, L.; Yin, X.

    1994-09-01

    MAD and MXI1, two recently described members of the basic helix-loop-helix (bHLH) gene family, encode proteins that dimerize with and modulate the DNA binding of max. In turn, mad-max or mxi1-max heterodimers or max homodimers can compete for DNA binding sites with dimers formed between max and myc oncoproteins and antagonize the transcriptional activities of this latter class of proteins. Using a combination of somatic cell mapping and fluorescence in situ hybridization techniques, we have determined the chromosomal locations of the MAD and MXI1 genes. The MAD gene maps to chromosome 2p12-p13, a region involved in translocations and deletions in acute and chronic lymphocytic leukemias as well as nonlymphocytic leukemias and Hodgkin disease. The MXI1 gene localizes to chromosome 10q24-q25, a region involved in translocations and deletions in acute and chronic lymphocytic leukemias and prostatic carcinomas. The availability of genomic clones of MAD and MXI1 will permit an assessment of their involvement in these diseases at the molecular level. 23 refs., 1 fig.

  11. Myrosin Idioblast Cell Fate and Development Are Regulated by the Arabidopsis Transcription Factor FAMA, the Auxin Pathway, and Vesicular Trafficking[W

    PubMed Central

    Li, Meng; Sack, Fred D.

    2014-01-01

    Crucifer shoots harbor a glucosinolate-myrosinase system that defends against insect predation. Arabidopsis thaliana myrosinase (thioglucoside glucohydrolase [TGG]) accumulates in stomata and in myrosin idioblasts (MIs). This work reports that the basic helix-loop-helix transcription factor FAMA that is key to stomatal development is also expressed in MIs. The loss of FAMA function abolishes MI fate as well as the expression of the myrosinase genes TGG1 and TGG2. MI cells have previously been reported to be located in the phloem. Instead, we found that MIs arise from the ground meristem rather than provascular tissues and thus are not homologous with phloem. Moreover, MI patterning and morphogenesis are abnormal when the function of the ARF-GEF gene GNOM is lost as well as when auxin efflux and vesicular trafficking are chemically disrupted. Stomata and MI cells constitute part of a wider system that reduces plant predation, the so-called “mustard oil bomb,” in which vacuole breakage in cells harboring myrosinase and glucosinolate yields a brew toxic to many animals, especially insects. This identification of the gene that confers the fate of MIs, as well as stomata, might facilitate the development of strategies for engineering crops to mitigate predation. PMID:25304201

  12. Acetylation of histone H4 plays a primary role in enhancing transcription factor binding to nucleosomal DNA in vitro.

    PubMed Central

    Vettese-Dadey, M; Grant, P A; Hebbes, T R; Crane- Robinson, C; Allis, C D; Workman, J L

    1996-01-01

    Core histones isolated from normal and butyrate-treated HeLa cells have been reconstituted into nucleosome cores in order to analyze the role of histone acetylation in enhancing transcription factor binding to recognition sites in nucleosomal DNA. Moderate stimulation of nucleosome binding was observed for the basic helix-loop-helix factor USF and the Zn cluster DNA binding domain factor GAL4-AH using heterogeneously acetylated histones. However, by coupling novel immunoblotting techniques to a gel retardation assay, we observed that nucleosome cores containing the most highly acetylated forms of histone H4 have the highest affinity for these two transcription factors. Western analysis of gel-purified USF-nucleosome and GAL4-AH-nucleosome complexes demonstrated the predominant presence of acetylated histone H4 relative to acetylated histone H3. Immunoprecipitation of USF-nucleosome complexes with anti-USF antibodies also demonstrated that these complexes were enriched preferentially in acetylated histone H4. These data show that USF and GAL4-AH preferentially interact with nucleosome cores containing highly acetylated histone H4. Acetylation of histone H4 thus appears to play a primary role in the structural changes that mediate enhanced binding of transcription factors to their recognition sites within nucleosomes. Images PMID:8665858

  13. The rice RING finger E3 ligase, OsHCI1, drives nuclear export of multiple substrate proteins and its heterogeneous overexpression enhances acquired thermotolerance

    PubMed Central

    Lim, Sung Don; Cho, Hyun Yong; Park, Yong Chan; Ham, Deok Jae; Lee, Ju Kyong; Jang, Cheol Seong

    2013-01-01

    Thermotolerance is very important for plant survival when plants are subjected to lethally high temperature. However, thus far little is known about the functions of RING E3 ligase in response to heat shock in plants. This study found that one rice gene encoding the RING finger protein was specifically induced by heat and cold stress treatments but not by salinity or dehydration and named it OsHCI1 (Oryza sativa heat and cold induced 1). Subcellular localization results showed that OsHCI1 was mainly associated with the Golgi apparatus and moved rapidly and extensively along the cytoskeleton. In contrast, OsHCI1 may have accumulated in the nucleus under high temperatures. OsHCI1 physically interacted with nuclear substrate proteins including a basic helix-loop-helix transcription factor. Transient co-overexpression of OsHCI1 and each of three nuclear proteins showed that their fluorescent signals moved into the cytoplasm as punctuate formations. Heterogeneous overexpression of OsHCI1 in Arabidopsis highly increased survival rate through acquired thermotolerance. It is proposed that OsHCI1 mediates nuclear–cytoplasmic trafficking of nuclear substrate proteins via monoubiquitination and drives an inactivation device for the nuclear proteins under heat shock. PMID:23698632

  14. Silencing of the inhibitor of DNA binding protein 4 (ID4) contributes to the pathogenesis of mouse and human CLL

    PubMed Central

    Chen, Shih-Shih; Claus, Rainer; Lucas, David M.; Yu, Lianbo; Qian, Jiang; Ruppert, Amy S.; West, Derek A.; Williams, Katie E.; Johnson, Amy J.; Sablitzky, Fred

    2011-01-01

    Inhibitor of DNA binding protein 4 (ID4) is a member of the dominant-negative basic helix-loop-helix transcription factor family that lacks DNA binding activity and has tumor suppressor function. ID4 promoter methylation has been reported in acute myeloid leukemia and chronic lymphocytic leukemia (CLL), although the expression, function, and clinical relevance of this gene have not been characterized in either disease. We demonstrate that the promoter of ID4 is consistently methylated to various degrees in CLL cells, and increased promoter methylation in a univariable analysis correlates with shortened patient survival. However, ID4 mRNA and protein expression is uniformly silenced in CLL cells irrespective of the degree of promoter methylation. The crossing of ID4+/? mice with E?-TCL1 mice triggers a more aggressive murine CLL as measured by lymphocyte count and inferior survival. Hemizygous loss of ID4 in nontransformed TCL1-positive B cells enhances cell proliferation triggered by CpG oligonucleotides and decreases sensitivity to dexamethasone-mediated apoptosis. Collectively, this study confirms the importance of the silencing of ID4 in murine and human CLL pathogenesis. PMID:21098398

  15. Enhancer mutations of Akv murine leukemia virus inhibit the induction of mature B-cell lymphomas and shift disease specificity towards the more differentiated plasma cell stage

    SciTech Connect

    Sorensen, Karina Dalsgaard; Kunder, Sandra; Quintanilla-Martinez, Leticia; Sorensen, Jonna; Schmidt, Joerg; Pedersen, Finn Skou . E-mail: fsp@mb.au.dk

    2007-05-25

    This study investigates the role of the proviral transcriptional enhancer for B-lymphoma induction by exogenous Akv murine leukemia virus. Infection of newborn inbred NMRI mice with Akv induced 35% plasma cell proliferations (PCPs) (consistent with plasmacytoma), 33% diffuse large B-cell lymphomas, 25% follicular B-cell lymphomas and few splenic marginal zone and small B-cell lymphomas. Deleting one copy of the 99-bp proviral enhancer sequence still allowed induction of multiple B-cell tumor types, although PCPs dominated (77%). Additional mutation of binding sites for the glucocorticoid receptor, Ets, Runx, or basic helix-loop-helix transcription factors in the proviral U3 region, however, shifted disease induction to almost exclusively PCPs, but had no major influence on tumor latency periods. Southern analysis of immunoglobulin rearrangements and ecotropic provirus integration patterns showed that many of the tumors/cell proliferations induced by each virus were polyclonal. Our results indicate that enhancer mutations weaken the ability of Akv to induce mature B-cell lymphomas prior to the plasma cell stage, whereas development of plasma cell proliferations is less dependent of viral enhancer strength.

  16. The Clock gene clone and its circadian rhythms in Pelteobagrus vachelli

    NASA Astrophysics Data System (ADS)

    Qin, Chuanjie; Shao, Ting

    2015-05-01

    The Clock gene, a key molecule in circadian systems, is widely distributed in the animal kingdom. We isolated a 936-bp partial cDNA sequence of the Clock gene ( Pva-clock) from the darkbarbel catfish Pelteobagrus vachelli that exhibited high identity with Clock genes of other species of fish and animals (65%-88%). The putative domains included a basic helix-loop-helix (bHLH) domain and two period-ARNT-single-minded (PAS) domains, which were also similar to those in other species of fish and animals. Pva-Clock was primarily expressed in the brain, and was detected in all of the peripheral tissues sampled. Additionally, the pattern of Pva-Clock expression over a 24-h period exhibited a circadian rhythm in the brain, liver and intestine, with the acrophase at zeitgeber time 21:35, 23:00, and 23:23, respectively. Our results provide insight into the function of the molecular Clock of P. vachelli.

  17. Neuronal differentiation of human iPS cells induced by baicalin via regulation of bHLH gene expression.

    PubMed

    Morita, Akihiro; Soga, Kohei; Nakayama, Hironobu; Ishida, Torao; Kawanishi, Shosuke; Sato, Eisuke F

    2015-09-25

    Efficient differentiation is important for regenerative medicine based on pluripotent stem cells, including treatment of neurodegenerative disorders and trauma. Baicalin promotes neuronal differentiation of neural stem/progenitor cells of rats and mice. To evaluate the suitability of baicalin for neuronal differentiation of human iPS cells, we investigated whether it promotes neuronal differentiation in human iPS cells and monitored basic helix-loop-helix (bHLH) gene expression during neuronal differentiation. Baicalin promoted neuronal differentiation and inhibited glial differentiation, suggesting that baicalin can influence the neuronal fate decision in human iPS cells. Notch signaling, which is upstream of bHLH proteins, was not involved in baicalin-induced neuronal differentiation. Baicalin treatment did not down-regulate Hes1 gene expression, but it reduced Hes1 protein levels and up-regulated Ascl1 gene expression. Thus, baicalin promoted neuronal differentiation via modulation of bHLH transcriptional factors. Therefore, baicalin has potential to be used as a small-molecule drug for regenerative treatment of neurodegenerative disorders. PMID:26277393

  18. SPEECHLESS integrates brassinosteroid and stomata signalling pathways.

    PubMed

    Gudesblat, Gustavo E; Schneider-Pizo?, Joanna; Betti, Camilla; Mayerhofer, Juliane; Vanhoutte, Isabelle; van Dongen, Walter; Boeren, Sjef; Zhiponova, Miroslava; de Vries, Sacco; Jonak, Claudia; Russinova, Eugenia

    2012-05-01

    Stomatal formation is regulated by multiple developmental and environmental signals, but how these signals are integrated to control this process is not fully understood. In Arabidopsis thaliana, the basic helix-loop-helix transcription factor SPEECHLESS (SPCH) regulates the entry, amplifying and spacing divisions that occur during stomatal lineage development. SPCH activity is negatively regulated by mitogen-activated protein kinase (MAPK)-mediated phosphorylation. Here, we show that in addition to MAPKs, SPCH activity is also modulated by brassinosteroid (BR) signalling. The GSK3/SHAGGY-like kinase BIN2 (BR INSENSITIVE2) phosphorylates residues overlapping those targeted by the MAPKs, as well as four residues in the amino-terminal region of the protein outside the MAPK target domain. These phosphorylation events antagonize SPCH activity and limit epidermal cell proliferation. Conversely, inhibition of BIN2 activity in vivo stabilizes SPCH and triggers excessive stomatal and non-stomatal cell formation. We demonstrate that through phosphorylation inputs from both MAPKs and BIN2, SPCH serves as an integration node for stomata and BR signalling pathways to control stomatal development in Arabidopsis. PMID:22466366

  19. The bHLH protein, MUTE, controls differentiation of stomata and the hydathode pore in Arabidopsis.

    PubMed

    Pillitteri, Lynn Jo; Bogenschutz, Naomi L; Torii, Keiko U

    2008-06-01

    Stomata are turgor-driven epidermal valves on the surface of plants that allow for efficient gas and water exchange between the plant and its environment. The Arabidopsis thaliana basic helix-loop-helix (bHLH) protein, MUTE, is a master regulator of stomatal differentiation where it is required for progression through the stomatal lineage and the differentiation of stomata. The genetic control of stomatal spacing across the epidermal surface is variable in different organs. For instance, a distinct suite of genes from those in leaves regulates stomatal patterning in hypocotyls. Here we report that regardless of organ type, MUTE controls downstream events directing stomatal differentiation, specifically the transition from meristemoid to guard mother cell. Ectopic MUTE expression is sufficient to over-ride cell fate specification in cell types that do not normally differentiate stomata. Furthermore, MUTE is required for the production of the structure evolutionarily related to stomata, the hydathode pore. Consistently, MUTE displays expression at the tip of cotyledons and leaves, thus co-localizing with the auxin maxima. However, MUTE itself was not regulated by the auxin, and the absence of hydathode pores in mute did not affect the auxin maxima. Surprisingly, our analysis revealed that the requirement for MUTE could be partially circumvented under conditions of compromised inhibitory signaling. PMID:18450784

  20. Cloning and characterization of DELLA genes in Artemisia annua.

    PubMed

    Shen, Q; Cui, J; Fu, X Q; Yan, T X; Tang, K X

    2015-01-01

    Gibberellins (GA) are some of the most important phytohormones involved in plant development. DELLA proteins are negative regulators of GA signaling in many plants. In this study, the full-length cDNA sequences of three DELLA genes were cloned from Artemisia annua. Phylogenetic analysis revealed that AaDELLA1 and AaDELLA2 were located in the same cluster, but AaDELLA3 was not. Subcellular localization analysis suggested that AaDELLAs can be targeted to the nucleus and/or cytoplasm. Real-time PCR indicated that all three AaDELLA genes exhibited the highest expression in seeds. Expression of all AaDELLA genes was enhanced by exogenous MeJA treatment but inhibited by GA3 treatment. Yeast two-hybrid assay showed that AaDELLAs could interact with basic helix-loop-helix transcription factor AaMYC2, suggesting that GA and JA signaling may be involved in cross-talk via DELLA and MYC2 interaction in A. annua. PMID:26345940

  1. Wingless blocks bristle formation and morphogenetic furrow progression in the eye through repression of Daughterless.

    PubMed

    Cadigan, Kenneth M; Jou, Austin D; Nusse, Roel

    2002-07-01

    In the developing eye, wingless activity represses proneural gene expression (and thus interommatidial bristle formation) and positions the morphogenetic furrow by blocking its initiation in the dorsal and ventral regions of the presumptive eye. We provide evidence that wingless mediates both effects, at least in part, through repression of the basic helix-loop-helix protein Daughterless. daughterless is required for high proneural gene expression and furrow progression. Ectopic expression of wingless blocks Daughterless expression in the proneural clusters. This repression, and that of furrow progression, can be mimicked by an activated form of armadillo and blocked by a dominant negative form of pangolin/TCF. Placing daughterless under the control of a heterologous promoter blocks the ability of ectopic wingless to inhibit bristle formation and furrow progression. hedgehog and decapentapleigic could not rescue the wingless furrow progression block, indicating that wingless acts downstream of these genes. In contrast, Atonal and Scute, which are thought to heterodimerize with Daughterless to promote furrow progression and bristle formation, respectively, can block ectopic wingless action. These results are summarized in a model where daughterless is a major, but probably not the only, target of wingless action in the eye. PMID:12091309

  2. Disruption of neurogenesis and cortical development in transgenic mice misexpressing Olig2, a gene in the Down syndrome critical region.

    PubMed

    Liu, Wei; Zhou, Hui; Liu, Lei; Zhao, Chuntao; Deng, Yaqi; Chen, Lina; Wu, Laiman; Mandrycky, Nicole; McNabb, Christopher T; Peng, Yuanbo; Fuchs, Perry N; Lu, Jie; Sheen, Volney; Qiu, Mengsheng; Mao, Meng; Richard Lu, Q

    2015-05-01

    The basic helix-loop-helix (bHLH) transcription factor Olig2 is crucial for mammalian central nervous system development. Human ortholog OLIG2 is located in the Down syndrome critical region in trisomy 21. To investigate the effect of Olig2 misexpression on brain development, we generated a developmentally regulated Olig2-overexpressing transgenic line with a Cre/loxP system. The transgenic mice with Olig2 misexpression in cortical neural stem/progenitor cells exhibited microcephaly, cortical dyslamination, hippocampus malformation, and profound motor deficits. Ectopic misexpression of Olig2 impaired cortical progenitor proliferation and caused precocious cell cycle exit. Massive neuronal cell death was detected in the developing cortex of Olig2-misexpressing mice. In addition, Olig2 misexpression led to a significant downregulation of neuronal specification factors including Ngn1, Ngn2 and Pax6, and a defect in cortical neurogenesis. Chromatin-immunoprecipitation and sequencing (ChIP-Seq) analysis indicates that Olig2 directly targets the promoter and/or enhancer regions of Nfatc4, Dscr1/Rcan1 and Dyrk1a, the critical neurogenic genes that contribute to Down syndrome phenotypes, and inhibits their expression. Together, our study suggests that Olig2 misexpression in neural stem cells elicits neurogenesis defects and neuronal cell death, which may contribute to developmental disorders including Down syndrome, where OLIG2 is triplicated on chromosomal 21. PMID:25747816

  3. Twist1 Is Essential for Tooth Morphogenesis and Odontoblast Differentiation.

    PubMed

    Meng, Tian; Huang, Yanyu; Wang, Suzhen; Zhang, Hua; Dechow, Paul C; Wang, Xiaofang; Qin, Chunlin; Shi, Bing; D'Souza, Rena N; Lu, Yongbo

    2015-12-01

    Twist1 is a basic helix-loop-helix-containing transcription factor that is expressed in the dental mesenchyme during the early stages of tooth development. To better delineate its roles in tooth development, we generated Twist1 conditional knockout embryos (Twist2(Cre) (/+);Twist1(fl/fl)) by breeding Twist1 floxed mice (Twist1(fl/fl)) with Twist2-Cre recombinase knockin mice (Twist2(Cre) (/+)). The Twist2(Cre) (/+);Twist1(fl/fl) embryos formed smaller tooth germs and abnormal cusps during early tooth morphogenesis. Molecular and histological analyses showed that the developing molars of the Twist2(Cre) (/+);Twist1(fl/fl) embryos had reduced cell proliferation and expression of fibroblast growth factors 3, 4, 9, and 10 and FGF receptors 1 and 2 in the dental epithelium and mesenchyme. In addition, 3-week-old renal capsular transplants of embryonic day 18.5 Twist2(Cre) (/+);Twist1(fl/fl) molars showed malformed crowns and cusps with defective crown dentin and enamel. Immunohistochemical analyses revealed that the implanted mutant molars had defects in odontoblast differentiation and delayed ameloblast differentiation. Furthermore, in vitro ChIP assays demonstrated that Twist1 was able to bind to a specific region of the Fgf10 promoter. In conclusion, our findings suggest that Twist1 plays crucial roles in regulating tooth development and that it may exert its functions through the FGF signaling pathway. PMID:26487719

  4. Regulation of Id2 expression by CCAAT/enhancer binding protein ?

    PubMed Central

    Karaya, Kazuhiro; Mori, Seiichi; Kimoto, Hisashi; Shima, Yoko; Tsuji, Yoshihito; Kurooka, Hisanori; Akira, Shizuo; Yokota, Yoshifumi

    2005-01-01

    Mice deficient for Id2, a negative regulator of basic helix–loop–helix (bHLH) transcription factors, exhibit a defect in lactation due to impaired lobuloalveolar development during pregnancy, similar to the mice lacking the CCAAT enhancer binding protein (C/EBP) ?. Here, we show that Id2 is a direct target of C/EBP?. Translocation of C/EBP? into the nucleus, which was achieved by using a system utilizing the fusion protein between C/EBP? and the ligand-binding domain of the human estrogen receptor (C/EBP?-ERT), demonstrated the rapid induction of endogenous Id2 expression. In reporter assays, transactivation of the Id2 promoter by C/EBP? was observed and, among three potential C/EBP? binding sites found in the 2.3 kb Id2 promoter region, the most proximal element was responsible for the transactivation. Electrophoretic mobility shift assay (EMSA) identified this element as a core sequence to which C/EBP? binds. Chromatin immunoprecipitation (ChIP) furthermore confirmed the presence of C/EBP? in the Id2 promoter region. Northern blotting showed that Id2 expression in C/EBP?-deficient mammary glands was reduced at 10 days post coitus (d.p.c.), compared with that in wild-type mammary glands. Thus, our data demonstrate that Id2 is a direct target of C/EBP? and provide insight into molecular mechanisms underlying mammary gland development during pregnancy. PMID:15809228

  5. The bHLH transcription factor BIS1 controls the iridoid branch of the monoterpenoid indole alkaloid pathway in Catharanthus roseus

    PubMed Central

    Van Moerkercke, Alex; Steensma, Priscille; Schweizer, Fabian; Pollier, Jacob; Gariboldi, Ivo; Payne, Richard; Vanden Bossche, Robin; Miettinen, Karel; Espoz, Javiera; Purnama, Purin Candra; Kellner, Franziska; Seppänen-Laakso, Tuulikki; O’Connor, Sarah E.; Rischer, Heiko; Memelink, Johan; Goossens, Alain

    2015-01-01

    Plants make specialized bioactive metabolites to defend themselves against attackers. The conserved control mechanisms are based on transcriptional activation of the respective plant species-specific biosynthetic pathways by the phytohormone jasmonate. Knowledge of the transcription factors involved, particularly in terpenoid biosynthesis, remains fragmentary. By transcriptome analysis and functional screens in the medicinal plant Catharanthus roseus (Madagascar periwinkle), the unique source of the monoterpenoid indole alkaloid (MIA)-type anticancer drugs vincristine and vinblastine, we identified a jasmonate-regulated basic helix–loop–helix (bHLH) transcription factor from clade IVa inducing the monoterpenoid branch of the MIA pathway. The bHLH iridoid synthesis 1 (BIS1) transcription factor transactivated the expression of all of the genes encoding the enzymes that catalyze the sequential conversion of the ubiquitous terpenoid precursor geranyl diphosphate to the iridoid loganic acid. BIS1 acted in a complementary manner to the previously characterized ethylene response factor Octadecanoid derivative-Responsive Catharanthus APETALA2-domain 3 (ORCA3) that transactivates the expression of several genes encoding the enzymes catalyzing the conversion of loganic acid to the downstream MIAs. In contrast to ORCA3, overexpression of BIS1 was sufficient to boost production of high-value iridoids and MIAs in C. roseus suspension cell cultures. Hence, BIS1 might be a metabolic engineering tool to produce sustainably high-value MIAs in C. roseus plants or cultures. PMID:26080427

  6. Insight into the mechanism of end-of-day far-red light (EODFR)-induced shade avoidance responses in Arabidopsis thaliana.

    PubMed

    Mizuno, Takeshi; Oka, Haruka; Yoshimura, Fumi; Ishida, Kai; Yamashino, Takafumi

    2015-12-01

    Shade avoidance responses are changes in plant architecture to reduce the part of a body that is in the shade in natural habitats. The most common warning signal that induces shade avoidance responses is reduction of red/far-red light ratio perceived by phytochromes. A pair of basic helix-loop-helix transcription factors, named PHYTOCHROME-INTERACTING FACTOR 4 (PIF4) and PIF5, is crucially involved in the shade avoidance-induced hypocotyl elongation in Arabidopsis thaliana. It has been recently reported that PIF7 also plays a role in this event. Here, we examined the involvement of these PIFs in end-of-day far-red light (EODFR) responses under light and dark cycle conditions. It was shown that PIF7 played a predominant role in the EODFR-dependent hypocotyl elongation. We propose the mechanism by which PIF7 together with PIF4 and PIF5 coordinately transcribes a set of downstream genes to promote elongation of hypocotyls in response to the EODFR treatment. PMID:26193333

  7. ICE1 of Poncirus trifoliata functions in cold tolerance by modulating polyamine levels through interacting with arginine decarboxylase

    PubMed Central

    Huang, Xiao-San; Zhang, Qinghua; Zhu, Dexin; Fu, Xingzheng; Wang, Min; Zhang, Qian; Moriguchi, Takaya; Liu, Ji-Hong

    2015-01-01

    ICE1 (Inducer of CBF Expression 1) encodes a MYC-like basic helix–loop–helix transcription factor that acts as a central regulator of cold response. In this study, we elucidated the function and underlying mechanisms of PtrICE1 from trifoliate orange [Poncirus trifoliata (L.) Raf.]. PtrICE1 was upregulated by cold, dehydration, and salt, with the greatest induction under cold conditions. PtrICE1 was localized in the nucleus and could bind to a MYC-recognizing sequence. Ectopic expression of PtrICE1 in tobacco and lemon conferred enhanced tolerance to cold stresses at either chilling or freezing temperatures. Yeast two-hybrid screening revealed that 21 proteins belonged to the PtrICE1 interactome, in which PtADC (arginine decarboxylase) was confirmed as a bona fide protein interacting with PtrICE1. Transcript levels of ADC genes in the transgenic lines were slightly elevated under normal growth condition but substantially increased under cold conditions, consistent with changes in free polyamine levels. By contrast, accumulation of the reactive oxygen species, H2O2 and O2 –, was appreciably alleviated in the transgenic lines under cold stress. Higher activities of antioxidant enzymes, such as superoxide dismutase and catalase, were detected in the transgenic lines under cold conditions. Taken together, these results demonstrated that PtrICE1 plays a positive role in cold tolerance, which may be due to modulation of polyamine levels through interacting with the ADC gene. PMID:25873670

  8. Point Mutations That Separate the Role of Saccharomyces Cerevisiae Centromere Binding Factor 1 in Chromosome Segregation from Its Role in Transcriptional Activation

    PubMed Central

    Foreman, P. K.; Davis, R. W.

    1993-01-01

    Centromere binding factor 1 (Cbf1p or CP1) binds to the CDEI region of Saccharomyces cerevisiae centromeres and is a member of the basic helix-loop-helix (bHLH) class of proteins. Deletion of the gene encoding Cbf1p results in an increased frequency of chromosome loss, hypersensitivity to low levels of microtubule disrupting drugs (such as thiabendazole and benomyl) and methionine auxotrophy. By polymerase chain reaction-based random mutagenesis of the CBF1 gene we have obtained a number of mutant alleles that make full-length protein with impaired function. The mutations in these alleles are clustered in or just downstream from the bHLH domain. Among the alleles obtained was a class that was more compromised for transcriptional activation and a class that was more compromised for chromosome loss and thiabendazole hypersensitivity. These results indicate that at least some aspects of the role of Cbf1p in chromosome segregation and transcriptional activation are distinct. In contrast, increased chromosome loss and thiabendazole hypersensitivity were not separated in any of the alleles, suggesting that these phenotypes reflect the same mechanistic defect. These observations are consistent with a model that suggests that one role of Cbf1p in chromosome segregation may be to improve the efficiency with which contact between the kinetochore and spindle microtubules is established or maintained. PMID:8243994

  9. Apterous A modulates wing size, bristle formation and patterning in Nilaparvata lugens

    PubMed Central

    Liu, Fangzhou; Li, Kaiyin; Li, Jie; Hu, Dingbang; Zhao, Jing; He, Yueping; Zou, Yulan; Feng, Yanni; Hua, Hongxia

    2015-01-01

    Apterous A (apA), a member of the LIM-homeobox gene family, plays a critical role in the development of wing. The achaete-scute Complex (AS-C) encodes basic helix-loop-helix (bHLH) transcription factors and functions in bristle development. In the present study, we cloned apA (NlapA) and an achaete-scute homologue (NlASH) from N. lugens. Levels of NlapA and NlASH were higher in nymphs than adults, with particularly high expression in the thorax of nymphs. NlapA expressed more highly in nymphs of the macropterous strain (MS) than those of the brachypterous strain (BS) at 2nd and 4th instar. Knockdown of NlapA and NlASH in vivo generated similar phenotypic defects in the wing (loss-of-bristles, twisted or erect wing). Silencing of NlapA in nymphs of MS led to decreased wing size in adults. Moreover, depletion of NlapA suppressed expression of NlDl, Nlsal, Nlser, Nlvg and Nlwg, both in MS and BS, but induced differential responses of Nlubx and Nlnotch expression between MS and BS. Notably, expression of NlASH was regulated by NlapA. These results collectively indicate that NlapA is an upstream modulator of wing size, bristle formation and patterning. Further studies on DNA-protein and protein-protein interactions are required to elucidate NlapA-mediated regulation of wing development. PMID:25995006

  10. A Light-Regulated Genetic Module Was Recruited to Carpel Development in Arabidopsis following a Structural Change to SPATULA[W

    PubMed Central

    Reymond, Mathieu C.; Brunoud, Géraldine; Chauvet, Aurélie; Martínez-Garcia, Jaime F.; Martin-Magniette, Marie-Laure; Monéger, Françoise; Scutt, Charles P.

    2012-01-01

    A key innovation of flowering plants is the female reproductive organ, the carpel. Here, we show that a mechanism that regulates carpel margin development in the model flowering plant Arabidopsis thaliana was recruited from light-regulated processes. This recruitment followed the loss from the basic helix-loop-helix transcription factor SPATULA (SPT) of a domain previously responsible for its negative regulation by phytochrome. We propose that the loss of this domain was a prerequisite for the light-independent expression in female reproductive tissues of a genetic module that also promotes shade avoidance responses in vegetative organs. Striking evidence for this proposition is provided by the restoration of wild-type carpel development to spt mutants by low red/far-red light ratios, simulating vegetation shade, which we show to occur via phytochrome B, PHYTOCHROME INTERACTING FACTOR4 (PIF4), and PIF5. Our data illustrate the potential of modular evolutionary events to generate rapid morphological change and thereby provide a molecular basis for neo-Darwinian theories that describe this nongradualist phenomenon. Furthermore, the effects shown here of light quality perception on carpel development lead us to speculate on the potential role of light-regulated mechanisms in plant organs that, like the carpel, form within the shade of surrounding tissues. PMID:22851763

  11. Hand2 regulates chondrogenesis in vitro and in vivo.

    PubMed

    Abe, Makoto; Michikami, Ikumi; Fukushi, Toshiya; Abe, Akiko; Maeda, Yoshinobu; Ooshima, Takashi; Wakisaka, Satoshi

    2010-05-01

    Hand2 is a transcription factor of the basic helix-loop-helix family that plays essential roles during development. Hand2 determines the anterior-posterior axis during limb development and there is also substantial evidence that Hand2 regulates limb skeletogenesis. However, little is known about how Hand2 might regulate skeletogenesis. Here we show that, in a limb bud micromass culture system, over-expression of Hand2 represses chondrogenesis and the expression of chondrocytic genes, Sox9, type II collagen and aggrecan. Furthermore, we show that Hand2 is induced by the activation of canonical Wnt signaling, which strongly represses chondrogenesis. Surprisingly, Hand2 repressed chondrogenesis in a DNA binding- and dimer formation-independent manner. To examine the in vivo role of Hand2 in mice, we targeted the expression of Hand2 to the cartilage using regulatory elements from the collagen II gene. The resulting transgenic mice displayed a dwarf phenotype, with axial, appendicular and craniofacial skeletal deformities. Hand2 strongly inhibited chondrogenesis in the axial and cranial base skeleton. In the sternum, Hand2 inhibited endochondral ossification by slowing chondrocyte maturation. These data support a model of Hand2 regulating endochondral ossification via at least two steps: (1) determination of the site of chondrogenesis by outlining the region of the future cartilage template and (2) regulation of the rate of chondrocyte maturation. PMID:19932774

  12. EsxB, a secreted protein from Bacillus anthracis forms two distinct helical bundles

    PubMed Central

    Fan, Yao; Tan, Kemin; Chhor, Gekleng; Butler, Emily K; Jedrzejczak, Robert P; Missiakas, Dominique; Joachimiak, Andrzej

    2015-01-01

    The EsxB protein from Bacillus anthracis belongs to the WXG100 family, a group of proteins secreted by a specialized secretion system. We have determined the crystal structures of recombinant EsxB and discovered that the small protein (?10 kDa), comprised of a helix-loop-helix (HLH) hairpin, is capable of associating into two different helical bundles. The two basic quaternary assemblies of EsxB are an antiparallel (AP) dimer and a rarely observed bisecting U (BU) dimer. This structural duality of EsxB is believed to originate from the heptad repeat sequence diversity of the first helix of its HLH hairpin, which allows for two alternative helix packing. The flexibility of EsxB and the ability to form alternative helical bundles underscore the possibility that this protein can serve as an adaptor in secretion and can form hetero-oligomeric helix bundle(s) with other secreted members of the WXG100 family, such as EsxW. The highly conserved WXG motif is located within the loop of the HLH hairpin and is mostly buried within the helix bundle suggesting that its role is mainly structural. The exact functions of the motif, including a proposed role as a secretion signal, remain unknown. PMID:26032645

  13. HEN1 encodes a 20-kilodalton phosphoprotein that binds an extended E-box motif as a homodimer.

    PubMed Central

    Brown, L; Baer, R

    1994-01-01

    HEN1 and HEN2 encode neuron-specific polypeptides that contain the basic helix-loop-helix (bHLH) motif, a protein dimerization and DNA-binding domain common to several known transcription factors. We now describe characteristics of the HEN1 gene product that are consistent with its postulated role as a transcription factor that functions during development of the mammalian nervous system. Thus, transcription of the HEN1 gene is activated upon the induction of neural differentiation in PC12 cells by nerve growth factor. HEN1 encodes a 20-kDa polypeptide (pp20HEN1) that is phosphorylated exclusively at serine residues and forms dimeric bHLH complexes either by self-association or by heterologous interaction with the E2A gene products (E12 or E47). The resultant HEN1/HEN1 homodimers and HEN1/E2A heterodimers bind DNA in a sequence-specific manner. Moreover, a binding site selection procedure revealed that HEN1-HEN1 homodimers preferentially recognize E-box motifs represented by an 18-bp consensus sequence (GGGNCG CAGCTGCGNCCC). The E-box half-site recognized by HEN1 polypeptides (GGGNCGCAG) is distinct from those of other known bHLH proteins, suggesting that HEN1 binds, an regulates the transcription of, a unique subset of target genes during neural development. Images PMID:8289804

  14. Overexpression of EcbHLH57 Transcription Factor from Eleusine coracana L. in Tobacco Confers Tolerance to Salt, Oxidative and Drought Stress.

    PubMed

    Babitha, K C; Vemanna, Ramu S; Nataraja, Karaba N; Udayakumar, M

    2015-01-01

    Basic helix-loop-helix (bHLH) transcription factors constitute one of the largest families in plants and are known to be involved in various developmental processes and stress tolerance. We report the characterization of a stress responsive bHLH transcription factor from stress adapted species finger millet which is homologous to OsbHLH57 and designated as EcbHLH57. The full length sequence of EcbHLH57 consisted of 256 amino acids with a conserved bHLH domain followed by leucine repeats. In finger millet, EcbHLH57 transcripts were induced by ABA, NaCl, PEG, methyl viologen (MV) treatments and drought stress. Overexpression of EcbHLH57 in tobacco significantly increased the tolerance to salinity and drought stress with improved root growth. Transgenic plants showed higher photosynthetic rate and stomatal conductance under drought stress that resulted in higher biomass. Under long-term salinity stress, the transgenic plants accumulated higher seed weight/pod and pod number. The transgenic plants were also tolerant to oxidative stress and showed less accumulation of H202 and MDA levels. The overexpression of EcbHLH57 enhanced the expression of stress responsive genes such as LEA14, rd29A, rd29B, SOD, APX, ADH1, HSP70 and also PP2C and hence improved tolerance to diverse stresses. PMID:26366726

  15. Upstream Stimulatory Factor-2 Mediates Quercetin-Induced Suppression of PAI-1 Gene Expression in Human Endothelial Cells

    PubMed Central

    Olave, Nélida C.; Grenett, Maximiliano H.; Cadeiras, Martin; Grenett, Hernan E.; Higgins, Paul J.

    2012-01-01

    The polyphenol quercetin (Quer) represses expression of the cardiovascular disease risk factor plasminogen activator inhibitor-1 (PAI-1) in cultured endothelial cells (ECs). Transfection of PAI-1 promoter-luciferase reporter deletion constructs identified a 251-bp fragment (nucleotides ?800 to ?549) responsive to Quer. Two E-box motifs (CACGTG), at map positions ?691 (E-box1) and ?575 (E-box2), are platforms for occupancy by several members of the c-MYC family of basic helix-loop-helix leucine zipper (bHLH-LZ) proteins. Promoter truncation and electrophoretic mobility shift/supershift analyses identified upstream stimulatory factor (USF)-1 and USF-2 as E-box1/E-box2 binding factors. ECs co-transfected with a 251 bp PAI-1 promoter fragment containing the two E-box motifs (p251/luc) and a USF-2 expression vector (pUSF-2/pcDNA) exhibited reduced luciferase activity versus p251/luc alone. Overexpression of USF-2 decreased, while transfection of a dominant-negative USF construct increased, EC growth consistent with the known anti-proliferative properties of USF proteins. Quer-induced decreases in PAI-1 expression and reduced cell proliferation may contribute, at least in part, to the cardioprotective benefit associated with daily intake of polyphenols. PMID:20626032

  16. FCA mediates thermal adaptation of stem growth by attenuating auxin action in Arabidopsis.

    PubMed

    Lee, Hyo-Jun; Jung, Jae-Hoon; Cortés Llorca, Lucas; Kim, Sang-Gyu; Lee, Sangmin; Baldwin, Ian T; Park, Chung-Mo

    2014-01-01

    Global warming is predicted to profoundly affect plant distribution and crop yield in the near future. Higher ambient temperature can influence diverse aspects of plant growth and development. In Arabidopsis, the basic helix-loop-helix transcription factor Phytochrome-Interacting Factor 4 (PIF4) regulates temperature-induced adaptive responses by modulating auxin biosynthesis. At high temperature, PIF4 directly activates expression of YUCCA8 (YUC8), a gene encoding an auxin biosynthetic enzyme, resulting in auxin accumulation. Here we demonstrate that the RNA-binding protein FCA attenuates PIF4 activity by inducing its dissociation from the YUC8 promoter at high temperature. At 28?°C, auxin content is elevated in FCA-deficient mutants that exhibit elongated stems but reduced in FCA-overexpressing plants that exhibit reduced stem growth. We propose that the FCA-mediated regulation of YUC8 expression tunes down PIF4-induced architectural changes to achieve thermal adaptation of stem growth at high ambient temperature. PMID:25400039

  17. The bHLH142 Transcription Factor Coordinates with TDR1 to Modulate the Expression of EAT1 and Regulate Pollen Development in Rice[C][W][OPEN

    PubMed Central

    Ko, Swee-Suak; Li, Min-Jeng; Sun-Ben Ku, Maurice; Ho, Yi-Cheng; Lin, Yi-Jyun; Chuang, Ming-Hsing; Hsing, Hong-Xian; Lien, Yi-Chen; Yang, Hui-Ting; Chang, Hung-Chia; Chan, Ming-Tsair

    2014-01-01

    Male sterility plays an important role in F1 hybrid seed production. We identified a male-sterile rice (Oryza sativa) mutant with impaired pollen development and a single T-DNA insertion in the transcription factor gene bHLH142. Knockout mutants of bHLH142 exhibited retarded meiosis and defects in tapetal programmed cell death. RT-PCR and in situ hybridization analyses showed that bHLH142 is specifically expressed in the anther, in the tapetum, and in meiocytes during early meiosis. Three basic helix-loop-helix transcription factors, UDT1 (bHLH164), TDR1 (bHLH5), and EAT1/DTD1 (bHLH141) are known to function in rice pollen development. bHLH142 acts downstream of UDT1 and GAMYB but upstream of TDR1 and EAT1 in pollen development. In vivo and in vitro assays demonstrated that bHLH142 and TDR1 proteins interact. Transient promoter assays demonstrated that regulation of the EAT1 promoter requires bHLH142 and TDR1. Consistent with these results, 3D protein structure modeling predicted that bHLH142 and TDR1 form a heterodimer to bind to the EAT1 promoter. EAT1 positively regulates the expression of AP37 and AP25, which induce tapetal programmed cell death. Thus, in this study, we identified bHLH142 as having a pivotal role in tapetal programmed cell death and pollen development. PMID:24894043

  18. Selection of human single domain antibodies recognizing the CMYC protein using enhanced intracellular antibody capture.

    PubMed

    Zeng, J; Li, H C; Tanaka, T; Rabbitts, T H

    2015-11-01

    Protein functions that are mediated by interaction with other proteins (protein-protein interactions, PPI) are important for normal cell biology and also in disease. Molecules that can interfere with PPI are required as laboratory tools to dissect function, as lead drug surrogates for target validation and as templates for drug discovery. We describe enhanced developments to Intracellular Antibody Capture (IAC) technology that can select antibody fragments able to interact with targets in cells. This is illustrated by the isolation of single heavy chain variable region domains binding to the basic-helix-loop-helix and leucine zipper region of the CMYC oncogenic protein. The enhanced IAC (eIAC) methodology deploys screening in yeast cells of a single diverse library initially with randomization only of CDR3. Further sequential randomization of CDR2 and CDR1 of three independently selected anti-CMYC clones illustrates an in vivo affinity maturation process. This concise eIAC approach facilitates the rapid selection of antibody fragments to explore the proteome interaction spectrum of mammalian cells and disease targeting. PMID:26319394

  19. TFBSshape: a motif database for DNA shape features of transcription factor binding sites.

    PubMed

    Yang, Lin; Zhou, Tianyin; Dror, Iris; Mathelier, Anthony; Wasserman, Wyeth W; Gordân, Raluca; Rohs, Remo

    2014-01-01

    Transcription factor binding sites (TFBSs) are most commonly characterized by the nucleotide preferences at each position of the DNA target. Whereas these sequence motifs are quite accurate descriptions of DNA binding specificities of transcription factors (TFs), proteins recognize DNA as a three-dimensional object. DNA structural features refine the description of TF binding specificities and provide mechanistic insights into protein-DNA recognition. Existing motif databases contain extensive nucleotide sequences identified in binding experiments based on their selection by a TF. To utilize DNA shape information when analysing the DNA binding specificities of TFs, we developed a new tool, the TFBSshape database (available at http://rohslab.cmb.usc.edu/TFBSshape/), for calculating DNA structural features from nucleotide sequences provided by motif databases. The TFBSshape database can be used to generate heat maps and quantitative data for DNA structural features (i.e., minor groove width, roll, propeller twist and helix twist) for 739 TF datasets from 23 different species derived from the motif databases JASPAR and UniPROBE. As demonstrated for the basic helix-loop-helix and homeodomain TF families, our TFBSshape database can be used to compare, qualitatively and quantitatively, the DNA binding specificities of closely related TFs and, thus, uncover differential DNA binding specificities that are not apparent from nucleotide sequence alone. PMID:24214955

  20. A role for Id2 in regulating photic entrainment of the mammalian circadian system.

    PubMed

    Duffield, Giles E; Watson, Nathan P; Mantani, Akio; Peirson, Stuart N; Robles-Murguia, Maricela; Loros, Jennifer J; Israel, Mark A; Dunlap, Jay C

    2009-02-24

    Inhibitor of DNA binding genes (Id1-Id4) encode helix-loop-helix (HLH) transcriptional repressors associated with development and tumorigenesis [1, 2], but little is known concerning the function(s) of these genes in normal adult animals. Id2 was identified in DNA microarray screens for rhythmically expressed genes [3-5], and further analysis revealed a circadian pattern of expression of all four Id genes in multiple tissues including the suprachiasmatic nucleus. To explore an in vivo function, we generated and characterized deletion mutations of Id2 and of Id4. Id2(-/-) mice exhibit abnormally rapid entrainment and an increase in the magnitude of the phase shift of the pacemaker. A significant proportion of mice also exhibit disrupted rhythms when maintained under constant darkness. Conversely, Id4(-/-) mice did not exhibit a noticeable circadian phenotype. In vitro studies using an mPer1 and an AVP promoter reporter revealed the potential for ID1, ID2, and ID3 proteins to interact with the canonical basic HLH clock proteins BMAL1 and CLOCK. These data suggest that the Id genes may be important for entrainment and operation of the mammalian circadian system, potentially acting through BMAL1 and CLOCK targets. PMID:19217292

  1. The mammalian single-minded (SIM) gene: Mouse cDNA structure and diencephalic expression indicate a candidate gene for Down syndrome

    SciTech Connect

    Yamaki, Akiko; Kudoh, Jun; Shindoh, Nobuaki

    1996-07-01

    We have recently isolated a human homolog (hSIM) of the Drosophila single-minded (sim) gene from the Down syndrome critical region of chromosome 21 using the exon trapping method. The Drosophila sim gene encodes a transcription factor that regulates the development of the central nervous system midline cell lineage. To elucidate the structure of the mammalian SIM protein, we have isolated cDNA clones from a mouse embryo cDNA library. The cDNA clones encode a polypeptide of 657 amino acids with a bHLH (basic-helix-loop-helix) domain, characteristic of a large family of transcription factors, and a PAS (Per-Arnt-Sim) domain in the amino-terminal half region. Both of these domains have striking sequence homology with human SIM and Drosophila SIM proteins. In contrast, the carboxy-terminal half of the mouse SIM protein consists of a proline-rich region with no sequence homology to the Drosophila SIM provator domain of a number of transcription factors. Whole-mount embryo in situ hybridization experiments revealed that the SIM mRNA is expressed prominently in the diencephalon during embryogenesis strongly suggest that the newly isolated mammalian SIM homolog may play a critical role in the development of the mammalian central nervous system. We propose that the human SIM gene may be one of the pathogenic genes of Down syndrome. 36 refs., 6 figs.

  2. Opposite roles of MRF4 and MyoD in cell proliferation and myogenic differentiation

    SciTech Connect

    Jin Xun; Kim, Jong-Gun; Oh, Myung-Joo; Oh, Ho-Yeon; Sohn, Young-Woo; Pian, Xumin; Yin, Jin Long; Beck, Samuel; Lee, Namkyung; Son, Jeesoo; Kim, Hyunggee; Yan Changguo; Wang Jihui; Choi, Yun-Jaie; Whang, Kwang Youn

    2007-12-21

    The basic helix-loop-helix myogenic regulatory factors play critical roles in skeletal myogenesis. Among the myogenic regulatory factors (MRFs), MRF4 shows a biphasic expression pattern during the formation of myotomes, although its function remains unclear. In this study, we used BEF (spontaneously immortalized bovine embryonic fibroblast that shows myogenic differentiation by overexpression of MyoD) and C2C12 cells to investigate the function of MRF4. Ectopic expressions of MRF4 did not stimulate myogenic differentiation in the BEF and C2C12 cells, but did show a marked increase of cell proliferation, upregulation of cyclin E, and downregulation of p21{sup WAF1}. Furthermore, MRF4 was found to induce degradation of the MyoD protein, which acts as a transcriptional activator for p21{sup WAF1}, and thus indicates that MRF4 accelerates cell proliferation by suppressing MyoD-dependent p21{sup WAF1} expression. However, forced expression of MyoD in the MRF4-overexpressing cells inhibited cell proliferation and partially induced myogenic differentiation, which suggests that MyoD is a potential negative intercessor of MRF4 in the regulation of the cell cycle. Taken together, these results indicate that MRF4 and MyoD play competitive roles in myogenesis by stimulating cell proliferation and differentiation, respectively.

  3. Pbx acts with Hand2 in early myocardial differentiation.

    PubMed

    Maves, Lisa; Tyler, Ashlee; Moens, Cecilia B; Tapscott, Stephen J

    2009-09-15

    Transcription factors of the basic helix-loop-helix (bHLH) family are critical regulators of muscle cell differentiation. For example, Myod drives skeletal muscle differentiation, and Hand2 potentiates cardiac muscle differentiation. Understanding how these bHLH factors regulate distinct transcriptional targets in a temporally and spatially controlled manner is critical for understanding their activity in cellular differentiation. We previously showed that Pbx homeodomain proteins modulate the activity of Myod to promote the differentiation of fast-twitch skeletal muscle. Here, we test the hypothesis that Pbx proteins are also necessary for cardiac muscle differentiation through interacting with Hand2. We show that Pbx proteins are required for the activation of cardiac muscle differentiation in zebrafish embryos. Loss of Pbx activity leads to delay of myocardial differentiation and subsequent defective cardiac morphogenesis, similar to reduced Hand2 activity. Genetic interaction experiments support the hypothesis that Pbx proteins modulate the activity of Hand2 in myocardial differentiation. Furthermore, we show that Pbx proteins directly bind the promoter of the myocardial differentiation gene myl7 in vitro, supporting a direct role for Pbx proteins in promoting cardiac muscle differentiation. Our findings demonstrate new roles for Pbx proteins in vertebrate cardiac development and also provide new insight into connections between the transcriptional regulation of skeletal and cardiac muscle differentiation programs. PMID:19607825

  4. Comparison of genome-wide binding of MyoD in normal human myogenic cells and rhabdomyosarcomas identifies regional and local suppression of promyogenic transcription factors.

    PubMed

    MacQuarrie, Kyle L; Yao, Zizhen; Fong, Abraham P; Diede, Scott J; Rudzinski, Erin R; Hawkins, Douglas S; Tapscott, Stephen J

    2013-02-01

    Rhabdomyosarcoma is a pediatric tumor of skeletal muscle that expresses the myogenic basic helix-loop-helix protein MyoD but fails to undergo terminal differentiation. Prior work has determined that DNA binding by MyoD occurs in the tumor cells, but myogenic targets fail to activate. Using MyoD chromatin immunoprecipitation coupled to high-throughput sequencing and gene expression analysis in both primary human muscle cells and RD rhabdomyosarcoma cells, we demonstrate that MyoD binds in a similar genome-wide pattern in both tumor and normal cells but binds poorly at a subset of myogenic genes that fail to activate in the tumor cells. Binding differences are found both across genomic regions and locally at specific sites that are associated with binding motifs for RUNX1, MEF2C, JDP2, and NFIC. These factors are expressed at lower levels in RD cells than muscle cells and rescue myogenesis when expressed in RD cells. MEF2C is located in a genomic region that exhibits poor MyoD binding in RD cells, whereas JDP2 exhibits local DNA hypermethylation in its promoter in both RD cells and primary tumor samples. These results demonstrate that regional and local silencing of differentiation factors contributes to the differentiation defect in rhabdomyosarcomas. PMID:23230269

  5. Comparison of Genome-Wide Binding of MyoD in Normal Human Myogenic Cells and Rhabdomyosarcomas Identifies Regional and Local Suppression of Promyogenic Transcription Factors

    PubMed Central

    MacQuarrie, Kyle L.; Yao, Zizhen; Fong, Abraham P.; Diede, Scott J.; Rudzinski, Erin R.; Hawkins, Douglas S.

    2013-01-01

    Rhabdomyosarcoma is a pediatric tumor of skeletal muscle that expresses the myogenic basic helix-loop-helix protein MyoD but fails to undergo terminal differentiation. Prior work has determined that DNA binding by MyoD occurs in the tumor cells, but myogenic targets fail to activate. Using MyoD chromatin immunoprecipitation coupled to high-throughput sequencing and gene expression analysis in both primary human muscle cells and RD rhabdomyosarcoma cells, we demonstrate that MyoD binds in a similar genome-wide pattern in both tumor and normal cells but binds poorly at a subset of myogenic genes that fail to activate in the tumor cells. Binding differences are found both across genomic regions and locally at specific sites that are associated with binding motifs for RUNX1, MEF2C, JDP2, and NFIC. These factors are expressed at lower levels in RD cells than muscle cells and rescue myogenesis when expressed in RD cells. MEF2C is located in a genomic region that exhibits poor MyoD binding in RD cells, whereas JDP2 exhibits local DNA hypermethylation in its promoter in both RD cells and primary tumor samples. These results demonstrate that regional and local silencing of differentiation factors contributes to the differentiation defect in rhabdomyosarcomas. PMID:23230269

  6. EsxB, a secreted protein from Bacillus anthracis forms two distinct helical bundles

    SciTech Connect

    Fan, Yao; Tan, Kemin; Chhor, Gekleng; Butler, Emily K.; Jedrzejczak, Robert P.; Missiakas, Dominique; Joachimiak, Andrzej

    2015-07-03

    The EsxB protein from Bacillus anthracis belongs to the WXG100 family, a group of proteins secreted by a specialized secretion system. We have determined the crystal structures of recombinant EsxB and discovered that the small protein (~10 kDa), comprised of a helix-loop-helix (HLH) hairpin, is capable of associating into two different helical bundles. The two basic quaternary assemblies of EsxB are an antiparallel (AP) dimer and a rarely observed bisecting U (BU) dimer. This structural duality of EsxB is believed to originate from the heptad repeat sequence diversity of the first helix of its HLH hairpin, which allows for two alternative helix packing. The flexibility of EsxB and the ability to form alternative helical bundles underscore the possibility that this protein can serve as an adaptor in secretion and can form hetero-oligomeric helix bundle(s) with other secreted members of the WXG100 family, such as EsxW. The highly conserved WXG motif is located within the loop of the HLH hairpin and is mostly buried within the helix bundle suggesting that its role is mainly structural. The exact functions of the motif, including a proposed role as a secretion signal, remain unknown.

  7. EsxB, a secreted protein from Bacillus anthracis forms two distinct helical bundles

    DOE PAGESBeta

    Fan, Yao; Tan, Kemin; Chhor, Gekleng; Butler, Emily K.; Jedrzejczak, Robert P.; Missiakas, Dominique; Joachimiak, Andrzej

    2015-07-03

    The EsxB protein from Bacillus anthracis belongs to the WXG100 family, a group of proteins secreted by a specialized secretion system. We have determined the crystal structures of recombinant EsxB and discovered that the small protein (~10 kDa), comprised of a helix-loop-helix (HLH) hairpin, is capable of associating into two different helical bundles. The two basic quaternary assemblies of EsxB are an antiparallel (AP) dimer and a rarely observed bisecting U (BU) dimer. This structural duality of EsxB is believed to originate from the heptad repeat sequence diversity of the first helix of its HLH hairpin, which allows for twomore »alternative helix packing. The flexibility of EsxB and the ability to form alternative helical bundles underscore the possibility that this protein can serve as an adaptor in secretion and can form hetero-oligomeric helix bundle(s) with other secreted members of the WXG100 family, such as EsxW. The highly conserved WXG motif is located within the loop of the HLH hairpin and is mostly buried within the helix bundle suggesting that its role is mainly structural. The exact functions of the motif, including a proposed role as a secretion signal, remain unknown.« less

  8. Phosphatidic acid and phosphoinositides facilitate liposome association of Yas3p and potentiate derepression of ARE1 (alkane-responsive element one)-mediated transcription control.

    PubMed

    Kobayashi, Satoshi; Hirakawa, Kiyoshi; Horiuchi, Hiroyuki; Fukuda, Ryouichi; Ohta, Akinori

    2013-12-01

    In the n-alkane assimilating yeast Yarrowia lipolytica, the expression of ALK1, encoding a cytochrome P450 that catalyzes terminal mono-oxygenation of n-alkanes, is induced by n-alkanes. The transcription of ALK1 is regulated by a heterocomplex that comprises the basic helix-loop-helix transcription activators, Yas1p and Yas2p, and binds to alkane-responsive element 1 (ARE1) in the ALK1 promoter. An Opi1 family transcription repressor, Yas3p, represses transcription by binding to Yas2p. Yas3p localizes in the nucleus when Y. lipolytica is grown on glucose but localizes to the endoplasmic reticulum (ER) upon the addition of n-alkanes. In this study, we showed that recombinant Yas3p binds to the acidic phospholipids, phosphatidic acid (PA) and phosphoinositides (PIPs), in vitro. The ARE1-mediated transcription was enhanced in vivo in mutants defective in an ortholog of the Saccharomyces cerevisiae gene PAH1, encoding PA phosphatase, and in an ortholog of SAC1, encoding PIP phosphatase in the ER. Truncation mutation analyses for Yas3p revealed two regions that bound to PA and PIPs. These results suggest that the interaction with acidic phospholipids is important for the n-alkane-induced association of Yas3p with the ER membrane. PMID:24120453

  9. Tomato Male sterile 1035 is essential for pollen development and meiosis in anthers

    PubMed Central

    Jeong, Hee-Jin; Kang, Jin-Ho; Zhao, Meiai; Kwon, Jin-Kyung; Choi, Hak-Soon; Bae, Jung Hwan; Lee, Hyun-ah; Joung, Young-Hee; Choi, Doil; Kang, Byoung-Cheorl

    2014-01-01

    Male fertility in flowering plants depends on proper cellular differentiation in anthers. Meiosis and tapetum development are particularly important processes in pollen production. In this study, we showed that the tomato male sterile (ms10 35) mutant of cultivated tomato (Solanum lycopersicum) exhibited dysfunctional meiosis and an abnormal tapetum during anther development, resulting in no pollen production. We demonstrated that Ms10 35 encodes a basic helix–loop–helix transcription factor that is specifically expressed in meiocyte and tapetal tissue from pre-meiotic to tetrad stages. Transgenic expression of the Ms10 35 gene from its native promoter complemented the male sterility of the ms10 35 mutant. In addition, RNA-sequencing-based transcriptome analysis revealed that Ms10 35 regulates 246 genes involved in anther development processes such as meiosis, tapetum development, cell-wall degradation, pollen wall formation, transport, and lipid metabolism. Our results indicate that Ms10 35 plays key roles in regulating both meiosis and programmed cell death of the tapetum during microsporogenesis. PMID:25262227

  10. Auxin signaling modules regulate maize inflorescence architecture.

    PubMed

    Galli, Mary; Liu, Qiujie; Moss, Britney L; Malcomber, Simon; Li, Wei; Gaines, Craig; Federici, Silvia; Roshkovan, Jessica; Meeley, Robert; Nemhauser, Jennifer L; Gallavotti, Andrea

    2015-10-27

    In plants, small groups of pluripotent stem cells called axillary meristems are required for the formation of the branches and flowers that eventually establish shoot architecture and drive reproductive success. To ensure the proper formation of new axillary meristems, the specification of boundary regions is required for coordinating their development. We have identified two maize genes, BARREN INFLORESCENCE1 and BARREN INFLORESCENCE4 (BIF1 and BIF4), that regulate the early steps required for inflorescence formation. BIF1 and BIF4 encode AUXIN/INDOLE-3-ACETIC ACID (Aux/IAA) proteins, which are key components of the auxin hormone signaling pathway that is essential for organogenesis. Here we show that BIF1 and BIF4 are integral to auxin signaling modules that dynamically regulate the expression of BARREN STALK1 (BA1), a basic helix-loop-helix (bHLH) transcriptional regulator necessary for axillary meristem formation that shows a striking boundary expression pattern. These findings suggest that auxin signaling directly controls boundary domains during axillary meristem formation and define a fundamental mechanism that regulates inflorescence architecture in one of the most widely grown crop species. PMID:26464512

  11. Conserved regulatory mechanism controls the development of cells with rooting functions in land plants

    PubMed Central

    Tam, Thomas Ho Yuen; Catarino, Bruno; Dolan, Liam

    2015-01-01

    Land plants develop filamentous cells—root hairs, rhizoids, and caulonemata—at the interface with the soil. Members of the group XI basic helix–loop–helix (bHLH) transcription factors encoded by LOTUS JAPONICUS ROOTHAIRLESS1-LIKE (LRL) genes positively regulate the development of root hairs in the angiosperms Lotus japonicus, Arabidopsis thaliana, and rice (Oryza sativa). Here we show that auxin promotes rhizoid and caulonema development by positively regulating the expression of PpLRL1 and PpLRL2, the two LRL genes in the Physcomitrella patens genome. Although the group VIII bHLH proteins, AtROOT HAIR DEFECTIVE6 and AtROOT HAIR DEFECTIVE SIX-LIKE1, promote root-hair development by positively regulating the expression of AtLRL3 in A. thaliana, LRL genes promote rhizoid development independently of PpROOT HAIR DEFECTIVE SIX-LIKE1 and PpROOT HAIR DEFECITVE SIX-LIKE2 (PpRSL1 and PpRSL2) gene function in P. patens. Together, these data demonstrate that both LRL and RSL genes are components of an ancient auxin-regulated gene network that controls the development of tip-growing cells with rooting functions among most extant land plants. Although this network has diverged in the moss and the angiosperm lineages, our data demonstrate that the core network acted in the last common ancestor of the mosses and angiosperms that existed sometime before 420 million years ago. PMID:26150509

  12. Inhibitory PAS domain protein is a negative regulator of hypoxia-inducible gene expression

    NASA Astrophysics Data System (ADS)

    Makino, Yuichi; Cao, Renhai; Svensson, Kristian; Bertilsson, Göran; Asman, Mikael; Tanaka, Hirotoshi; Cao, Yihai; Berkenstam, Anders; Poellinger, Lorenz

    2001-11-01

    Alteration of gene expression is a crucial component of adaptive responses to hypoxia. These responses are mediated by hypoxia-inducible transcription factors (HIFs). Here we describe an inhibitory PAS (Per/Arnt/Sim) domain protein, IPAS, which is a basic helix-loop-helix (bHLH)/PAS protein structurally related to HIFs. IPAS contains no endogenous transactivation function but demonstrates dominant negative regulation of HIF-mediated control of gene expression. Ectopic expression of IPAS in hepatoma cells selectively impairs induction of genes involved in adaptation to a hypoxic environment, notably the vascular endothelial growth factor (VEGF) gene, and results in retarded tumour growth and tumour vascular density in vivo. In mice, IPAS was predominantly expressed in Purkinje cells of the cerebellum and in corneal epithelium of the eye. Expression of IPAS in the cornea correlates with low levels of expression of the VEGF gene under hypoxic conditions. Application of an IPAS antisense oligonucleotide to the mouse cornea induced angiogenesis under normal oxygen conditions, and demonstrated hypoxia-dependent induction of VEGF gene expression in hypoxic corneal cells. These results indicate a previously unknown mechanism for negative regulation of angiogenesis and maintenance of an avascular phenotype.

  13. The molecular basis for venation patterning of pigmentation and its effect on pollinator attraction in flowers of Antirrhinum.

    PubMed

    Shang, Yongjin; Venail, Julien; Mackay, Steve; Bailey, Paul C; Schwinn, Kathy E; Jameson, Paula E; Martin, Cathie R; Davies, Kevin M

    2011-01-01

    Pigment stripes associated with veins (venation) is a common flower colour pattern. The molecular genetics and function of venation were investigated in the genus Antirrhinum, in which venation is determined by Venosa (encoding an R2R3MYB transcription factor). Pollinator preferences were measured by field tests with Antirrhinum majus. Venosa function was examined using in situ hybridization and transient overexpression. The origin of the venation trait was examined by molecular phylogenetics. Venation and full-red flower colouration provide a comparable level of advantage for pollinator attraction relative to palely pigmented or white lines. Ectopic expression of Venosa confers pigmentation outside the veins. Venosa transcript is produced only in small areas of the corolla between the veins and the adaxial epidermis. Phylogenetic analyses suggest that venation patterning is an ancestral trait in Antirrhinum. Different accessions of three species with full-red pigmentation with or without venation patterning have been found. Epidermal-specific venation is defined through overlapping expression domains of the MYB (myoblastoma) and bHLH (basic Helix-Loop-Helix) co-regulators of anthocyanin biosynthesis, with the bHLH providing epidermal specificity and Venosa vein specificity. Venation may be the ancestral trait, with full-red pigmentation a derived, polyphyletic trait. Venation patterning is probably not fixed once species evolve full-red floral pigmentation. PMID:21039563

  14. The Role of Atonal Factors in Mechanosensory Cell Specification and Function.

    PubMed

    Cai, Tiantian; Groves, Andrew K

    2015-12-01

    Atonal genes are basic helix-loop-helix transcription factors that were first identified as regulating the formation of mechanoreceptors and photoreceptors in Drosophila. Isolation of vertebrate homologs of atonal genes has shown these transcription factors to play diverse roles in the development of neurons and their progenitors, gut epithelial cells, and mechanosensory cells in the inner ear and skin. In this article, we review the molecular function and regulation of atonal genes and their targets, with particular emphasis on the function of Atoh1 in the development, survival, and function of hair cells of the inner ear. We discuss cell-extrinsic signals that induce Atoh1 expression and the transcriptional networks that regulate its expression during development. Finally, we discuss recent work showing how identification of Atoh1 target genes in the cerebellum, spinal cord, and gut can be used to propose candidate Atoh1 targets in tissues such as the inner ear where cell numbers and biochemical material are limiting. PMID:25339580

  15. Origin of a Non-Clarke's Column Division of the Dorsal Spinocerebellar Tract and the Role of Caudal Proprioceptive Neurons in Motor Function.

    PubMed

    Yuengert, Rachel; Hori, Kei; Kibodeaux, Erin E; McClellan, Jacob X; Morales, Justin E; Huang, Teng-Wei P; Neul, Jeffrey L; Lai, Helen C

    2015-11-10

    Proprioception, the sense of limb and body position, is essential for generating proper movement. Unconscious proprioceptive information travels through cerebellar-projecting neurons in the spinal cord and medulla. The progenitor domain defined by the basic-helix-loop-helix (bHLH) transcription factor, ATOH1, has been implicated in forming these cerebellar-projecting neurons; however, their precise contribution to proprioceptive tracts and motor behavior is unknown. Significantly, we demonstrate that Atoh1-lineage neurons in the spinal cord reside outside Clarke's column (CC), a main contributor of neurons relaying hindlimb proprioception, despite giving rise to the anatomical and functional correlate of CC in the medulla, the external cuneate nucleus (ECu), which mediates forelimb proprioception. Elimination of caudal Atoh1-lineages results in mice with relatively normal locomotion but unable to perform coordinated motor tasks. Altogether, we reveal that proprioceptive nuclei in the spinal cord and medulla develop from more than one progenitor source, suggesting an avenue to uncover distinct proprioceptive functions. PMID:26527010

  16. The SCL gene specifies haemangioblast development from early mesoderm.

    PubMed Central

    Gering, M; Rodaway, A R; Göttgens, B; Patient, R K; Green, A R

    1998-01-01

    The SCL gene encodes a basic helix-loop-helix (bHLH) transcription factor that is essential for the development of all haematopoietic lineages. SCL is also expressed in endothelial cells, but its function is not essential for specification of endothelial progenitors and the role of SCL in endothelial development is obscure. We isolated the zebrafish SCL homologue and show that it was co-expressed in early mesoderm with markers of haematopoietic, endothelial and pronephric progenitors. Ectopic expression of SCL mRNA in zebrafish embryos resulted in overproduction of common haematopoietic and endothelial precursors, perturbation of vasculogenesis and concomitant loss of pronephric duct and somitic tissue. Notochord and neural tube formation were unaffected. These results provide the first evidence that SCL specifies formation of haemangioblasts, the proposed common precursor of blood and endothelial lineages. Our data also underline the striking similarities between the role of SCL in haematopoiesis/vasculogenesis and the function of other bHLH proteins in muscle and neural development. PMID:9670018

  17. Overexpression of EcbHLH57 Transcription Factor from Eleusine coracana L. in Tobacco Confers Tolerance to Salt, Oxidative and Drought Stress

    PubMed Central

    Nataraja, Karaba N.; Udayakumar, M.

    2015-01-01

    Basic helix-loop-helix (bHLH) transcription factors constitute one of the largest families in plants and are known to be involved in various developmental processes and stress tolerance. We report the characterization of a stress responsive bHLH transcription factor from stress adapted species finger millet which is homologous to OsbHLH57 and designated as EcbHLH57. The full length sequence of EcbHLH57 consisted of 256 amino acids with a conserved bHLH domain followed by leucine repeats. In finger millet, EcbHLH57 transcripts were induced by ABA, NaCl, PEG, methyl viologen (MV) treatments and drought stress. Overexpression of EcbHLH57 in tobacco significantly increased the tolerance to salinity and drought stress with improved root growth. Transgenic plants showed higher photosynthetic rate and stomatal conductance under drought stress that resulted in higher biomass. Under long-term salinity stress, the transgenic plants accumulated higher seed weight/pod and pod number. The transgenic plants were also tolerant to oxidative stress and showed less accumulation of H202 and MDA levels. The overexpression of EcbHLH57 enhanced the expression of stress responsive genes such as LEA14, rd29A, rd29B, SOD, APX, ADH1, HSP70 and also PP2C and hence improved tolerance to diverse stresses. PMID:26366726

  18. Characterization of MxFIT, an iron deficiency induced transcriptional factor in Malus xiaojinensis.

    PubMed

    Yin, Lili; Wang, Yi; Yuan, Mudan; Zhang, Xinzhong; Xu, Xuefeng; Han, Zhenhai

    2014-02-01

    Iron deficiency often results in nutritional disorder in fruit trees. Transcription factors play an important role in the regulation of iron uptake. In this study, we isolated an iron deficiency response transcription factor gene, MxFIT, from an iron-efficient apple genotype of Malus xiaojinensis. MxFIT encoded a basic helix-loop-helix protein and contained a 966 bp open reading frame. MxFIT protein was targeted to the nucleus in onion epidermal cells and showed strong transcriptional activation in yeast cells. Spatiotemporal expression analysis revealed that MxFIT was up-regulated in roots under iron deficiency at both mRNA and protein levels, while almost no expression was detected in leaves irrespective of iron supply. Ectopic expression of MxFIT resulted in enhanced iron deficiency responses in Arabidopsis under iron deficiency and stronger resistance to iron deficiency. Thus, MxFIT might be involved in iron uptake and plays an important role in iron deficiency response. PMID:24389022

  19. Twist-2 Controls Myeloid Lineage Development and Function

    PubMed Central

    Sharabi, Andrew B; Aldrich, Melissa; Sosic, Drazen; Olson, Eric N; Friedman, Alan D; Lee, Sung-Hyung; Chen, Si-Yi

    2008-01-01

    Basic helix-loop-helix (bHLH) transcription factors play critical roles in lymphoid and erythroid development; however, little is known about their role in myeloid lineage development. In this study, we identify the bHLH transcription factor Twist-2 as a key negative regulator of myeloid lineage development, as manifested by marked increases in mature myeloid populations of macrophages, neutrophils, and basophils in Twist-2–deficient mice. Mechanistic studies demonstrate that Twist-2 inhibits the proliferation as well as differentiation of granulocyte macrophage progenitors (GMP) by interacting with and inhibiting the transcription factors Runx1 and C/EBP?. Moreover, Twist-2 was found to have a contrasting effect on cytokine production: inhibiting the production of proinflammatory cytokines such as interleukin-12 (IL-12) and interferon-? (IFN?) while promoting the regulatory cytokine IL-10 by myeloid cells. The data from further analyses suggest that Twist-2 activates the transcription factor c-Maf, leading to IL-10 expression. In addition, Twist-2 was found to be essential for endotoxin tolerance. Thus, this study reveals the critical role of Twist-2 in regulating the development of myeloid lineages, as well as the function and inflammatory responses of mature myeloid cells. PMID:19090621

  20. Regulation of mouse sterol regulatory element-binding protein-1c gene (SREBP-1c) by oxysterol receptors, LXR? and LXR?

    PubMed Central

    Repa, Joyce J.; Liang, Guosheng; Ou, Jiafu; Bashmakov, Yuriy; Lobaccaro, Jean-Marc A.; Shimomura, Iichiro; Shan, Bei; Brown, Michael S.; Goldstein, Joseph L.; Mangelsdorf, David J.

    2000-01-01

    The liver X receptors (LXRs) are members of the nuclear hormone receptor superfamily that are bound and activated by oxysterols. These receptors serve as sterol sensors to regulate the transcription of gene products that control intracellular cholesterol homeostasis through catabolism and transport. In this report, we describe a novel LXR target, the sterol regulatory element-binding protein-1c gene (SREBP-1c), which encodes a membrane-bound transcription factor of the basic helix-loop-helix-leucine zipper family. SREBP-1c expression was markedly increased in mouse tissues in an LXR-dependent manner by dietary cholesterol and synthetic agonists for both LXR and its heterodimer partner, the retinoid X receptor (RXR). Expression of the related gene products, SREBP-1a and SREBP-2, were not increased. Analysis of the mouse SREBP-1c gene promoter revealed an RXR/LXR DNA-binding site that is essential for this regulation. The transcriptional increase in SREBP-1c mRNA by RXR/LXR was accompanied by a similar increase in the level of the nuclear, active form of the SREBP-1c protein and an increase in fatty acid synthesis. Because this active form of SREBP-1c controls the transcription of genes involved in fatty acid biosynthesis, our results reveal a unique regulatory interplay between cholesterol and fatty acid metabolism. PMID:11090130

  1. The Transcriptional Repressor MYB2 Regulates Both Spatial and Temporal Patterns of Proanthocyandin and Anthocyanin Pigmentation in Medicago truncatula.

    PubMed

    Jun, Ji Hyung; Liu, Chenggang; Xiao, Xirong; Dixon, Richard A

    2015-10-01

    Accumulation of anthocyanins and proanthocyanidins (PAs) is limited to specific cell types and developmental stages, but little is known about how antagonistically acting transcriptional regulators work together to determine temporal and spatial patterning of pigmentation at the cellular level, especially for PAs. Here, we characterize MYB2, a transcriptional repressor regulating both anthocyanin and PA biosynthesis in the model legume Medicago truncatula. MYB2 was strongly upregulated by MYB5, a major regulator of PA biosynthesis in M. truncatula and a component of MYB-basic helix loop helix-WD40 (MBW) activator complexes. Overexpression of MYB2 abolished anthocyanin and PA accumulation in M. truncatula hairy roots and Arabidopsis thaliana seeds, respectively. Anthocyanin deposition was expanded in myb2 mutant seedlings and flowers accompanied by increased anthocyanin content. PA mainly accumulated in the epidermal layer derived from the outer integument in the M. truncatula seed coat, starting from the hilum area. The area of PA accumulation and ANTHOCYANIDIN REDUCTASE expression was expanded into the seed body at the early stage of seed development in the myb2 mutant. Genetic, biochemical, and cell biological evidence suggests that MYB2 functions as part of a multidimensional regulatory network to define the temporal and spatial pattern of anthocyanin and PA accumulation linked to developmental processes. PMID:26410301

  2. Hypoxia Inhibits Myogenic Differentiation through p53 Protein-dependent Induction of Bhlhe40 Protein.

    PubMed

    Wang, Chao; Liu, Weiyi; Liu, Zuojun; Chen, Long; Liu, Xiaoqi; Kuang, Shihuan

    2015-12-11

    Satellite cells are muscle-resident stem cells capable of self-renewal and differentiation to repair injured muscles. However, muscle injury often leads to an ischemic hypoxia environment that impedes satellite cell differentiation and reduces the efficiency of muscle regeneration. Here we performed microarray analyses and identified the basic helix-loop-helix family transcription factor Bhlhe40 as a candidate mediator of the myogenic inhibitory effect of hypoxia. Bhlhe40 is strongly induced by hypoxia in satellite cell-derived primary myoblasts. Overexpression of Bhlhe40 inhibits Myog expression and mimics the effect of hypoxia on myogenesis. Inhibition of Bhlhe40, conversely, up-regulates Myog expression and promotes myogenic differentiation. Importantly, Bhlhe40 knockdown rescues myogenic differentiation under hypoxia. Mechanistically, Bhlhe40 binds to the proximal E-boxes of the Myog promoter and reduces the binding affinity and transcriptional activity of MyoD on Myog. Interestingly, hypoxia induces Bhlhe40 expression independent of HIF1? but through a novel p53-dependent signaling pathway. Our study establishes a crucial role of Bhlhe40 in mediating the repressive effect of hypoxia on myogenic differentiation and suggests that inhibition of Bhlhe40 or p53 may facilitate muscle regeneration after ischemic injuries. PMID:26468276

  3. CCAR1 is required for Ngn3-mediated endocrine differentiation

    SciTech Connect

    Lu, Chung-Kuang; Lai, Yi-Chyi; Lin, Yung-Fu; Chen, Hau-Ren; Chiang, Ming-Ko

    2012-02-10

    Highlights: Black-Right-Pointing-Pointer We identify CCAR1 to directly interact with Ngn3. Black-Right-Pointing-Pointer CCAR1 is co-localized with Ngn3 in the nucleus. Black-Right-Pointing-Pointer CCAR1 cooperates with Ngn3 in activating NeuroD expression. Black-Right-Pointing-Pointer CCAR1 is required for Ngn3-mediated PANC-1 transdifferentiation. -- Abstract: Neurogenin3 (Ngn3) is a basic helix-loop-helix transcription factor that specifies pancreatic endocrine cell fates during pancreas development. It can also initiate a transdifferentiation program when expressed in pancreatic exocrine and ductal cells. However, how Ngn3 initiates a transcriptional cascade to achieve endocrine differentiation is still poorly understood. Here, we show that cell cycle and apoptosis regulator 1 (CCAR1), which is a transcriptional coactivator for nuclear receptors, also interacts with Ngn3. The association between Ngn3 and CCAR1 was verified by pull-down assays and co-immunoprecipitation analyses. Using gene reporter assays, we found that CCAR1 is essential for Ngn3 to activate the expression of the reporter genes containing the NeuroD promoter. Moreover, down-regulation of endogenous CCAR1 in the PANC-1 pancreatic ductal cell line inhibits the transdifferentiation program initiated by Ngn3. CCAR1 is, therefore, a novel partner of Ngn3 in mediating endocrine differentiation.

  4. Role of AHR, AHRR and ARNT in response to dioxin-like PCBs in Spaurus aurata.

    PubMed

    Calò, Margherita; Licata, Patrizia; Bitto, Alessandra; Lo Cascio, Patrizia; Interdonato, Monica; Altavilla, Domenica

    2014-12-01

    The aryl hydrocarbon receptor (AHR) mediates a variety of biological responses to ubiquitous dioxin and PCB dioxin-like. AHR together with ARNT, AHRR, represent a novel basic helix-loop-helix/PAS family of transcriptional regulators. Their interplay may affect the xenobiotic response. The aim of this study was to investigate, by histological, immunohistochemical investigations and western-blot analysis, the expression of AHR, ARNT and AHRR in liver of seabrem (Spaurus aurata) after exposure at different time to dioxin-like PCB126 in order to deep the knowledge about their specific role. The findings showed a significant increase of AHR and ARNT expression in juvenile fishes after 12 h than control group. The induction of AHR and ARNT is also significant at 24 and 72 hours compared to the control group. Furthemore, induction of AHRR expression has proved to increase both 12 h but this induction does not seem significant to 24 and 72 hours. The most important data of this work is that the induction of AHRR, when the action of the toxic persistence substances, as dioxin and PCB-126, it is not enough to reduce AHR signaling and thus its hyperactivation leads to toxic effects in seabrem (Spaurus aurata). All this confirms the importance of AHR ligands as new class of drugs that can be directed against severe disease such as cancer. PMID:25060310

  5. Development of inner ear afferent connections: forming primary neurons and connecting them to the developing sensory epithelia

    NASA Technical Reports Server (NTRS)

    Fritzsch, Bernd

    2003-01-01

    The molecular and cellular origin of the primary neurons of the inner ear, the vestibular and spiral neurons, is reviewed including how they connect to the specific sensory epithelia and what the molecular nature of their survival is. Primary neurons of the ear depend on a single basic Helix-Loop-Helix (bHLH) protein for their formation, neurogenin 1 (ngn1). An immediate downstream gene is the bHLH gene neuronal differentiation (NeuroD). Targeted null mutations of ngn1 results in absence of primary neuron formation; targeted null mutation of NeuroD results in loss of almost all spiral and many vestibular neurons. NeuroD and a later expressed gene, Brn3a, play a role in pathfinding to and within sensory epithelia. The molecular nature of this pathfinding property is unknown. Reduction of hair cells in ngn1 null mutations suggests a clonal relationship with primary neurons. This relationship may play some role in specifying the identity of hair cells and the primary neurons that connect with them. Primary neuron neurites growth to sensory epithelia is initially independent of trophic factors released from developing sensory epithelia, but becomes rapidly dependent on those factors. Null mutations of specific neurotrophic factors lose distinct primary neuron populations which undergo rapid embryonic cell death.

  6. Arabidopsis thaliana ICE2 gene: phylogeny, structural evolution and functional diversification from ICE1.

    PubMed

    Kurbidaeva, Amina; Ezhova, Tatiana; Novokreshchenova, Maria

    2014-12-01

    The ability to tolerate environmental stresses is crucial for all living organisms, and gene duplication is one of the sources for evolutionary novelties. Arabidopsis thaliana INDUCER OF CBF EXPRESSION1 and 2 (ICE1 and ICE2) encode MYC-type bHLH (basic helix-loop-helix) transcription factors. They confer cold stress tolerance by induction of the CBF/DREB1 regulon and regulate stomata formation. Although ICE2 is closely related to ICE1, its origin and role in cold response remains uncertain. Here, we used a bioinformatics/phylogenetic approach to uncover the ICE2 evolutionary history, structural evolution and functional divergence from the putative ancestral gene. Sequence diversification from ICE1 included the gain of cis-acting elements in ICE2 promoter sequence that may provide meristem-specific and defense-related gene expression. By analyzing transgenic Arabidopsis lines with ICE2 over-expression we showed that it contributes to stomata formation, flowering time regulation and cold response. Constitutive ICE2 expression led to induced meristem freezing tolerance, resulting from activation of CBF1 and CBF3 genes and ABA biosynthesis by NCED3 induction. We presume that ICE2 gene has originated from a duplication event about 17.9MYA followed by sub- and neofunctionalization of the ancestral ICE1 gene. Moreover, we predict its role in pathogen resistance and flowering time regulation. PMID:25443829

  7. Unique defense strategy by the endoplasmic reticulum body in plants.

    PubMed

    Yamada, Kenji; Hara-Nishimura, Ikuko; Nishimura, Mikio

    2011-12-01

    The endoplasmic reticulum (ER) is a site for the production of secretory proteins. Plants have developed ER subdomains for protein storage. The ER body is one such structure, which is observed in Brassicaceae plants. ER bodies accumulate in seedlings and roots or in wounded leaves in Arabidopsis. ER bodies contain high amounts of the ?-glucosidases PYK10/BGLU23 in seedlings and roots or BGLU18 in wounded tissues. These results suggest that ER bodies are involved in the metabolism of glycoside molecules, presumably to produce repellents against pests and fungi. When Arabidopsis roots are homogenized, PYK10 formed large protein aggregates that include other ?-glucosidases (BGLU21 and BGLU22), GDSL lipase-like proteins (GLL22) and cytosolic jacalin-related lectins (PBP1/JAL30, JAL31, JAL33, JAL34 and JAL35). Glucosidase activity increases by the aggregate formation. NAI1, a basic helix-loop-helix transcription factor, regulates the expression of the ER body proteins PYK10 and NAI2. Reduced expression of NAI2, PYK10 and BGLU21 resulted in abnormal ER body formation, indicating that these components regulate ER body formation. PYK10, BGLU21 and BGLU22 possess hydrolytic activity for scopolin, a coumaroyl glucoside that accumulates in the roots of Arabidopsis, and nai1 and pyk10 mutants are more susceptible to the symbiotic fungus Piriformospora indica. Therefore, it appears that the ER body is a unique organelle of Brassicaceae plants that is important for defense against pests and fungi. PMID:22102697

  8. PIF1 directly and indirectly regulates chlorophyll biosynthesis to optimize the greening process in Arabidopsis

    PubMed Central

    Moon, Jennifer; Zhu, Ling; Shen, Hui; Huq, Enamul

    2008-01-01

    Plants depend on light signals to modulate many aspects of their development and optimize their photosynthetic capacity. Phytochromes (phys), a family of photoreceptors, initiate a signal transduction pathway that alters expression of a large number of genes to induce these responses. Recently, phyA and phyB were shown to bind members of a basic helix–loop–helix family of transcription factors called phy-interacting factors (PIFs). PIF1 negatively regulates chlorophyll biosynthesis and seed germination in the dark, and light-induced degradation of PIF1 relieves this negative regulation to promote photomorphogenesis. Here, we report that PIF1 regulates expression of a discrete set of genes in the dark, including protochlorophyllide oxidoreductase (POR), ferrochelatase (FeChII), and heme oxygenase (HO3), which are involved in controlling the chlorophyll biosynthetic pathway. Using ChIP and DNA gel-shift assays, we demonstrate that PIF1 directly binds to a G-box (CACGTG) DNA sequence element present in the PORC promoter. Moreover, in transient assays, PIF1 activates transcription of PORC in a G-box-dependent manner. These data strongly suggest that PIF1 directly and indirectly regulates key genes involved in chlorophyll biosynthesis to optimize the greening process in Arabidopsis. PMID:18591656

  9. The role of Atonal factors in mechanosensory cell specification and function

    PubMed Central

    Cai, Tiantian; Groves, Andrew K.

    2015-01-01

    atonal genes are basic helix-loop-helix transcription factors that were first identified as regulating the formation of mechanoreceptors and photoreceptors in Drosophila. Isolation of vertebrate homologs of atonal genes has shown these transcription factors to play diverse roles in the development of neurons and their progenitors, gut epithelial cells and mechanosensory cells in the inner ear and skin. In this article, we review the molecular function and regulation of atonal genes and their targets, with particular emphasis on the function of Atoh1 in the development, survival and function of hair cells of the inner ear. We discuss cell-extrinsic signals that induce Atoh1 expression, and the transcriptional networks that regulate its expression during development. Finally, we discuss recent work showing how identification of Atoh1 target genes in the cerebellum, spinal cord and gut can be used to propose candidate Atoh1 targets in tissues such as the inner ear where cell numbers and biochemical material are limiting. PMID:25339580

  10. The bHLH transcription factor BIS1 controls the iridoid branch of the monoterpenoid indole alkaloid pathway in Catharanthus roseus.

    PubMed

    Van Moerkercke, Alex; Steensma, Priscille; Schweizer, Fabian; Pollier, Jacob; Gariboldi, Ivo; Payne, Richard; Vanden Bossche, Robin; Miettinen, Karel; Espoz, Javiera; Purnama, Purin Candra; Kellner, Franziska; Seppänen-Laakso, Tuulikki; O'Connor, Sarah E; Rischer, Heiko; Memelink, Johan; Goossens, Alain

    2015-06-30

    Plants make specialized bioactive metabolites to defend themselves against attackers. The conserved control mechanisms are based on transcriptional activation of the respective plant species-specific biosynthetic pathways by the phytohormone jasmonate. Knowledge of the transcription factors involved, particularly in terpenoid biosynthesis, remains fragmentary. By transcriptome analysis and functional screens in the medicinal plant Catharanthus roseus (Madagascar periwinkle), the unique source of the monoterpenoid indole alkaloid (MIA)-type anticancer drugs vincristine and vinblastine, we identified a jasmonate-regulated basic helix-loop-helix (bHLH) transcription factor from clade IVa inducing the monoterpenoid branch of the MIA pathway. The bHLH iridoid synthesis 1 (BIS1) transcription factor transactivated the expression of all of the genes encoding the enzymes that catalyze the sequential conversion of the ubiquitous terpenoid precursor geranyl diphosphate to the iridoid loganic acid. BIS1 acted in a complementary manner to the previously characterized ethylene response factor Octadecanoid derivative-Responsive Catharanthus APETALA2-domain 3 (ORCA3) that transactivates the expression of several genes encoding the enzymes catalyzing the conversion of loganic acid to the downstream MIAs. In contrast to ORCA3, overexpression of BIS1 was sufficient to boost production of high-value iridoids and MIAs in C. roseus suspension cell cultures. Hence, BIS1 might be a metabolic engineering tool to produce sustainably high-value MIAs in C. roseus plants or cultures. PMID:26080427

  11. Genetic Factors for Enhancement of Nicotine Levels in Cultivated Tobacco

    PubMed Central

    Wang, Bingwu; Lewis, Ramsey S.; Shi, Junli; Song, Zhongbang; Gao, Yulong; Li, Wenzheng; Chen, Hongxia; Qu, Rongda

    2015-01-01

    Nicotine has practical applications relating to smoking cessation devices and alternative nicotine products. Genetic manipulation for increasing nicotine content in cultivated tobacco (Nicotiana tabacum L.) may be of value for industrial purposes, including the possibility of enhancing the efficiency of nicotine extraction. Biotechnological approaches have been evaluated in connection with this objective, but field-based results are few. Here, we report characterization of two genes encoding basic-helix-loop-helix (bHLH) transcription factors (TFs), NtMYC2a and NtMYC2b from tobacco. Overexpression of NtMYC2a increased leaf nicotine levels in T1 transgenic lines approximately 2.3-fold in greenhouse-grown plants of tobacco cultivar ‘NC 95?. Subsequent field testing of T2 and T3 generations of transgenic NtMYC2a overexpression lines showed nicotine concentrations were 76% and 58% higher than control lines, respectively. These results demonstrated that the increased nicotine trait was stably inherited to the T2 and T3 generations, indicating the important role that NtMYC2a plays in regulating nicotine accumulation in N. tabacum and the great potential of NtMYC2a overexpression in tobacco plants for industrial nicotine production. Collected data in this study also indicated a negative feedback inhibition of nicotine biosynthesis. Further enhancement of nicotine accumulation in tobacco leaf may require modification of the processes of nicotine transport and deposition. PMID:26626731

  12. PIFs: Systems Integrators in Plant Development[W

    PubMed Central

    Leivar, Pablo; Monte, Elena

    2014-01-01

    Phytochrome-interacting factors (PIFs) are members of the Arabidopsis thaliana basic helix-loop-helix family of transcriptional regulators that interact specifically with the active Pfr conformer of phytochrome (phy) photoreceptors. PIFs are central regulators of photomorphogenic development that act to promote stem growth, and this activity is reversed upon interaction with phy in response to light. Recently, significant progress has been made in defining the transcriptional networks directly regulated by PIFs, as well as the convergence of other signaling pathways on the PIFs to modulate growth. Here, we summarize and highlight these findings in the context of PIFs acting as integrators of light and other signals. We discuss progress in our understanding of the transcriptional and posttranslational regulation of PIFs that illustrates the integration of light with hormonal pathways and the circadian clock, and we review seedling hypocotyl growth as a paradigm of PIFs acting at the interface of these signals. Based on these advances, PIFs are emerging as required factors for growth, acting as central components of a regulatory node that integrates multiple internal and external signals to optimize plant development. PMID:24481072

  13. An evolutionarily conserved DNA architecture determines target specificity of the TWIST family bHLH transcription factors

    PubMed Central

    Chang, Andrew T.; Liu, Yuanjie; Ayyanathan, Kasirajan; Benner, Chris; Jiang, Yike; Prokop, Jeremy W.; Paz, Helicia; Wang, Dong; Li, Hai-Ri; Fu, Xiang-Dong

    2015-01-01

    Basic helix–loop–helix (bHLH) transcription factors recognize the canonical E-box (CANNTG) to regulate gene transcription; however, given the prevalence of E-boxes in a genome, it has been puzzling how individual bHLH proteins selectively recognize E-box sequences on their targets. TWIST is a bHLH transcription factor that promotes epithelial–mesenchymal transition (EMT) during development and tumor metastasis. High-resolution mapping of TWIST occupancy in human and Drosophila genomes reveals that TWIST, but not other bHLH proteins, recognizes a unique double E-box motif with two E-boxes spaced preferentially by 5 nucleotides. Using molecular modeling and binding kinetic analyses, we found that the strict spatial configuration in the double E-box motif aligns two TWIST–E47 dimers on the same face of DNA, thus providing a high-affinity site for a highly stable intramolecular tetramer. Biochemical analyses showed that the WR domain of TWIST dimerizes to mediate tetramer formation, which is functionally required for TWIST-induced EMT. These results uncover a novel mechanism for a bHLH transcription factor to recognize a unique spatial configuration of E-boxes to achieve target specificity. The WR–WR domain interaction uncovered here sets an example of target gene specificity of a bHLH protein being controlled allosterically by a domain outside of the bHLH region. PMID:25762439

  14. Twist2 contributes to cisplatin-resistance of ovarian cancer through the AKT/GSK-3? signaling pathway

    PubMed Central

    WANG, TIAN; LI, YAN; TUERHANJIANG, ABIDAN; WANG, WENWEN; WU, ZHANGYING; YUAN, MING; MAITITUOHETI, MAYINUER; WANG, SHIXUAN

    2014-01-01

    Cisplatin is regularly used in the treatment of ovarian cancer. However, the drug only provides a modest survival advantage, primarily due to chemoresistance and the upregulation of antiapoptotic machineries in ovarian cancer cells. Therefore, targeting the mechanisms responsible for cisplatin resistance in ovarian cancer cells may improve the therapeutic outcomes. Twist basic helix-loop-helix transcription factor 2 (Twist2) is a novel zinc finger transcription factor that has been indicated to be an important inducer of epithelial-mesenchymal transition, which has been shown to be involved in various phases of tumorigenicity and progression. However, whether Twist2 suppression increases the chemosensitivity of ovarian cancer cells to chemotherapeutic agents remains unclear. In the present study, Twist2 expression was found to differ between human ovarian cisplatin-sensitive cancer cell line, OV2008, and the resistant variant, C13K cells. Twist2 plasmids or RNA interference were then utilized to alter Twist2 expression in OV2008 or C13K cells, respectively, to further assess apoptosis, cell viability and cell growth, as well as a possible mechanism. The results of the present study indicated that Twist2 plays a crucial role in the chemoresistance of ovarian cancer. In addition, the downregulation of Twist2 expression may facilitate apoptosis and recover the sensitivity of chemoresistant ovarian cancer through the protein kinase B/glycogen synthase kinase-3? pathway. Therefore, Twist2 depletion may be a promising approach to ovarian cancer therapy. PMID:24944676

  15. The Role of GH/IGF-I Axis in Muscle Homeostasis During Weightlessness

    NASA Technical Reports Server (NTRS)

    Schwartz, Robert J.

    1997-01-01

    Exposure to reduced gravity during space travel profoundly alters the loads placed on bone and muscle. Astronauts suffer significant losses of muscle and bone strength during weightlessness. Exercise as a countermeasure is only partially effective in remedying severe muscle atrophy and bone demineralization. Similar wasting of muscles and bones affects people on Earth during prolonged bed rest or immobilization due to injury. In the absence of weight bearing activity, atrophy occurs primarily in the muscles that act in low power, routine movements and in maintaining posture. Hormonal disfunction could contribute in part to the loss of muscle and bone during spaceflight. Reduced levels of human Growth Hormone (hGH) were found in astronauts during space flight, as well as reduced GH secretory activity was observed from the anterior pituitary in 7-day space flight rats. Growth hormone has been shown to be required for maintenance of muscle mass and bone mineralization, in part by mediating the biosynthesis IGF-I, a small polypeptide growth factor. IGF biosynthesis and secretion plays an important role in potentiating muscle cell differentiation and has been shown to drive the expression of myogenin, a myogenic specific basic helix-loop-helix factor. IGF-I has also been shown to have an important role in potentiating muscle regeneration, repair and adult muscle hypertrophy.

  16. ULTRAPETALA trxG Genes Interact with KANADI Transcription Factor Genes to Regulate Arabidopsis Gynoecium Patterning[C][W][OPEN

    PubMed Central

    Monfared, Mona M.; Shemyakina, Elena A.; Fletcher, Jennifer C.

    2014-01-01

    Organ formation relies upon precise patterns of gene expression that are under tight spatial and temporal regulation. Transcription patterns are specified by several cellular processes during development, including chromatin remodeling, but little is known about how chromatin-remodeling factors contribute to plant organogenesis. We demonstrate that the trithorax group (trxG) gene ULTRAPETALA1 (ULT1) and the GARP transcription factor gene KANADI1 (KAN1) organize the Arabidopsis thaliana gynoecium along two distinct polarity axes. We show that ULT1 activity is required for the kan1 adaxialized polarity defect, indicating that ULT1 and KAN1 act oppositely to regulate the adaxial-abaxial axis. Conversely, ULT1 and KAN1 together establish apical-basal polarity by promoting basal cell fate in the gynoecium, restricting the expression domain of the basic helix-loop-helix transcription factor gene SPATULA. Finally, we show that ult alleles display dose-dependent genetic interactions with kan alleles and that ULT and KAN proteins can associate physically. Our findings identify a dual role for plant trxG factors in organ patterning, with ULT1 and KAN1 acting antagonistically to pattern the adaxial-abaxial polarity axis but jointly to pattern the apical-basal axis. Our data indicate that the ULT proteins function to link chromatin-remodeling factors with DNA binding transcription factors to regulate target gene expression. PMID:25381352

  17. Conserved regulatory mechanism controls the development of cells with rooting functions in land plants.

    PubMed

    Tam, Thomas Ho Yuen; Catarino, Bruno; Dolan, Liam

    2015-07-21

    Land plants develop filamentous cells-root hairs, rhizoids, and caulonemata-at the interface with the soil. Members of the group XI basic helix-loop-helix (bHLH) transcription factors encoded by LOTUS JAPONICUS ROOTHAIRLESS1-LIKE (LRL) genes positively regulate the development of root hairs in the angiosperms Lotus japonicus, Arabidopsis thaliana, and rice (Oryza sativa). Here we show that auxin promotes rhizoid and caulonema development by positively regulating the expression of PpLRL1 and PpLRL2, the two LRL genes in the Physcomitrella patens genome. Although the group VIII bHLH proteins, AtROOT HAIR DEFECTIVE6 and AtROOT HAIR DEFECTIVE SIX-LIKE1, promote root-hair development by positively regulating the expression of AtLRL3 in A. thaliana, LRL genes promote rhizoid development independently of PpROOT HAIR DEFECTIVE SIX-LIKE1 and PpROOT HAIR DEFECITVE SIX-LIKE2 (PpRSL1 and PpRSL2) gene function in P. patens. Together, these data demonstrate that both LRL and RSL genes are components of an ancient auxin-regulated gene network that controls the development of tip-growing cells with rooting functions among most extant land plants. Although this network has diverged in the moss and the angiosperm lineages, our data demonstrate that the core network acted in the last common ancestor of the mosses and angiosperms that existed sometime before 420 million years ago. PMID:26150509

  18. Chimeric Restriction Enzymes: What Is Next?

    PubMed Central

    Smith, Jeff

    2014-01-01

    Chimeric restriction enzymes are a novel class of engineered nucleases in which the non-specific DNA cleavage domain of FokI (a type IIS restriction endonuclease) is fused to other DNA-binding motifs. The latter include the three common eukaryotic DNA-binding motifs, namely the helix-turn-helix motif, the zinc finger motif and the basic helix-loop-helix protein containing a leucine zipper motif. Such chimeric nucleases have been shown to make specific cuts in vitro very close to the expected recognition sequences. The most important chimeric nucleases are those based on zinc finger DNA-binding proteins because of their modular structure. Recently, one such chimeric nuclease, Zif-QQR-FN was shown to find and cleave its target in vivo. This was tested by microinjection of DNA substrates and the enzyme into frog oocytes (Carroll et al., 1999). The injected enzyme made site-specific double-strand breaks in the targets even after assembly of the DNA into chromatin. In addition, this cleavage activated the target molecules for efficient homologous recombination. Since the recognition specificity of zinc fingers can be manipulated experimentally, chimeric nucleases could be engineered so as to target a specific site within a genome. The availability of such engineered chimeric restriction enzymes should make it feasible to do genome engineering, also commonly referred to as gene therapy. PMID:10494832

  19. Mesogenin 1 is a master regulator of paraxial presomitic mesoderm differentiation

    PubMed Central

    Chalamalasetty, Ravindra B.; Garriock, Robert J.; Dunty, William C.; Kennedy, Mark W.; Jailwala, Parthav; Si, Han; Yamaguchi, Terry P.

    2014-01-01

    Neuromesodermal (NM) stem cells generate neural and paraxial presomitic mesoderm (PSM) cells, which are the respective progenitors of the spinal cord and musculoskeleton of the trunk and tail. The Wnt-regulated basic helix-loop-helix (bHLH) transcription factor mesogenin 1 (Msgn1) has been implicated as a cooperative regulator working in concert with T-box genes to control PSM formation in zebrafish, although the mechanism is unknown. We show here that, in mice, Msgn1 alone controls PSM differentiation by directly activating the transcriptional programs that define PSM identity, epithelial-mesenchymal transition, motility and segmentation. Forced expression of Msgn1 in NM stem cells in vivo reduced the contribution of their progeny to the neural tube, and dramatically expanded the unsegmented mesenchymal PSM while blocking somitogenesis and notochord differentiation. Expression of Msgn1 was sufficient to partially rescue PSM differentiation in Wnt3a?/? embryos, demonstrating that Msgn1 functions downstream of Wnt3a as the master regulator of PSM differentiation. Our data provide new insights into how cell fate decisions are imposed by the expression of a single transcriptional regulator. PMID:25371364

  20. The bHLH Transcription Factor Hand Regulates the Expression of Genes Critical to Heart and Muscle Function in Drosophila melanogaster

    PubMed Central

    Hallier, Benjamin; Hoffmann, Julia; Roeder, Thomas; Tögel, Markus; Meyer, Heiko; Paululat, Achim

    2015-01-01

    Hand proteins belong to the highly conserved family of basic Helix-Loop-Helix transcription factors and are critical to distinct developmental processes, including cardiogenesis and neurogenesis in vertebrates. In Drosophila melanogaster a single orthologous hand gene is expressed with absence of the respective protein causing semilethality during early larval instars. Surviving adult animals suffer from shortened lifespan associated with a disorganized myofibrillar structure being apparent in the dorsal vessel, the wing hearts and in midgut tissue. Based on these data, the major biological significance of Hand seems to be related to muscle development, maintenance or function; however, up to now the physiological basis for Hand functionality remains elusive. Thus, the identification of genes whose expression is, directly or indirectly, regulated by Hand has considerable relevance with respect to understanding its biological functionality in flies and vertebrates. Beneficially, hand mutants are viable and exhibit affected tissues, which renders Drosophila an ideal model to investigate up- or downregulated target genes by a comparative microarray approach focusing on the respective tissues from mutant specimens. Our present work reveals for the first time that Drosophila Hand regulates the expression of numerous genes of diverse physiological relevancy, including distinct factors required for proper muscle development and function such as Zasp52 or Msp-300. These results relate Hand activity to muscle integrity and functionality and may thus be highly beneficial to the evaluation of corresponding hand phenotypes. PMID:26252215

  1. Virulence factors of geminivirus interact with MYC2 to subvert plant resistance and promote vector performance.

    PubMed

    Li, Ran; Weldegergis, Berhane T; Li, Jie; Jung, Choonkyun; Qu, Jing; Sun, Yanwei; Qian, Hongmei; Tee, ChuanSia; van Loon, Joop J A; Dicke, Marcel; Chua, Nam-Hai; Liu, Shu-Sheng; Ye, Jian

    2014-12-01

    A pathogen may cause infected plants to promote the performance of its transmitting vector, which accelerates the spread of the pathogen. This positive effect of a pathogen on its vector via their shared host plant is termed indirect mutualism. For example, terpene biosynthesis is suppressed in begomovirus-infected plants, leading to reduced plant resistance and enhanced performance of the whiteflies (Bemisia tabaci) that transmit these viruses. Although begomovirus-whitefly mutualism has been known, the underlying mechanism is still elusive. Here, we identified ?C1 of Tomato yellow leaf curl China virus, a monopartite begomovirus, as the viral genetic factor that suppresses plant terpene biosynthesis. ?C1 directly interacts with the basic helix-loop-helix transcription factor MYC2 to compromise the activation of MYC2-regulated terpene synthase genes, thereby reducing whitefly resistance. MYC2 associates with the bipartite begomoviral protein BV1, suggesting that MYC2 is an evolutionarily conserved target of begomoviruses for the suppression of terpene-based resistance and the promotion of vector performance. Our findings describe how this viral pathogen regulates host plant metabolism to establish mutualism with its insect vector. PMID:25490915

  2. Arabidopsis HFR1 is a potential nuclear substrate regulated by the Xanthomonas type III effector XopD(Xcc8004).

    PubMed

    Tan, Choon Meng; Li, Meng-Ying; Yang, Pei-Yun; Chang, Shu Heng; Ho, Yi-Ping; Lin, Hong; Deng, Wen-Ling; Yang, Jun-Yi

    2015-01-01

    XopDXcc8004, a type III effector of Xanthomonas campestris pv. campestris (Xcc) 8004, is considered a shorter version of the XopD, which lacks the N-terminal domain. To understand the functions of XopDXcc8004, in planta, a transgenic approach combined with inducible promoter to analyze the effects of XopDXcc8004 in Arabidopsis was done. Here, the expression of XopDXcc8004, in Arabidopsis elicited the accumulation of host defense-response genes. These molecular changes were dependent on salicylic acid and correlated with lesion-mimic phenotypes observed in XVE::XopDXcc8004 transgenic plants. Moreover, XopDXcc8004 was able to desumoylate HFR1, a basic helix-loop-helix transcription factor involved in photomorphogenesis, through SUMO protease activity. Interestingly, the hfr1-201 mutant increased the expression of host defense-response genes and displayed a resistance phenotype to Xcc8004. These data suggest that HFR1 is involved in plant innate immunity and is potentially regulated by XopDXcc8004. PMID:25647296

  3. Arabidopsis HFR1 Is a Potential Nuclear Substrate Regulated by the Xanthomonas Type III Effector XopDXcc8004

    PubMed Central

    Tan, Choon Meng; Li, Meng-Ying; Yang, Pei-Yun; Chang, Shu Heng; Ho, Yi-Ping; Lin, Hong; Deng, Wen-Ling; Yang, Jun-Yi

    2015-01-01

    XopDXcc8004, a type III effector of Xanthomonas campestris pv. campestris (Xcc) 8004, is considered a shorter version of the XopD, which lacks the N-terminal domain. To understand the functions of XopDXcc8004, in planta, a transgenic approach combined with inducible promoter to analyze the effects of XopDXcc8004 in Arabidopsis was done. Here, the expression of XopDXcc8004, in Arabidopsis elicited the accumulation of host defense-response genes. These molecular changes were dependent on salicylic acid and correlated with lesion-mimic phenotypes observed in XVE::XopDXcc8004 transgenic plants. Moreover, XopDXcc8004 was able to desumoylate HFR1, a basic helix-loop-helix transcription factor involved in photomorphogenesis, through SUMO protease activity. Interestingly, the hfr1-201 mutant increased the expression of host defense-response genes and displayed a resistance phenotype to Xcc8004. These data suggest that HFR1 is involved in plant innate immunity and is potentially regulated by XopDXcc8004. PMID:25647296

  4. Pivotal role of Twist in skeletal biology and pathology.

    PubMed

    Miraoui, Hichem; Marie, Pierre J

    2010-11-15

    Basic Helix-loop-Helix (bHLH) factors play important roles in development and disease. Recent functional and genetic analyses revealed that the bHLH factor Twist1 is a critical modulator of mesenchymal cell fate during skeletal development. Specifically, studies in mice and humans showed that Twist1 controls mesenchymal stem cell differentiation into chondrocytes, osteoblasts or adipocytes via direct and indirect mechanisms. In a physiological context, Twist1 targets several molecular mechanisms to induce positive or negative effects on osteoblastic cell growth, differentiation and survival. In a pathological context, Twist1 loss-of-function mutations induce premature cranial suture fusion (craniosynostosis) in the Saethre-Chotzen syndrome. In this syndrome, expansion of cranial osteogenesis at the suture level results from alterations in the balance between osteoprogenitor cell proliferation, differentiation and apoptosis. These studies provide mechanisms by which Twist1 plays a pivotal role in skeletal cell fate in normal and pathologic conditions, which may offer therapeutic perspectives in conditions where mesenchymal cell behaviour is compromised. PMID:20696219

  5. Molecular silencing of Twist1 enhances osteogenic differentiation of murine mesenchymal stem cells: implication of FGFR2 signaling.

    PubMed

    Miraoui, Hichem; Severe, Nicolas; Vaudin, Pascal; Pagès, Jean-Christophe; Marie, Pierre J

    2010-08-01

    The capacity of mesenchymal stem cells (MSCs) to differentiate into functional osteoblasts is tightly controlled by transcription factors that trigger osteoblast commitment and differentiation. The role of Twist1, a basic helix-loop-helix (bHLH) transcription factor, in osteogenic differentiation of MSCs remains unclear. Here we investigated the role of Twist1 in the osteogenic differentiation program of murine C3H10T1/2 mesenchymal cells. We showed that molecular silencing of Twist1 using short hairpin RNA (shRNA) expression moderately increased C3H10T1/2 cell proliferation and had no effect on cell survival. In contrast, Twist1 silencing enhanced osteoblast gene expression and matrix mineralization in vitro. Biochemical analyses revealed that Twist1 silencing increased the expression of FGFR2 protein level, which was reduced by a mutant Runx2. Consistent with this finding, Twist1 silencing increased ERK1/2 and PI3K signaling. Moreover, molecular or pharmacological inhibition of FGFR2 or of ERK1/2 and PI3K signaling partly abolished the increased osteoblast gene expression induced by Twist1 silencing in C3H10T1/2 cells. These results reveal that Twist1 silencing upregulates osteoblast differentiation of murine mesenchymal cells in part via activation of FGFR2 expression and downstream signaling pathways, which provides novel insights into the molecular signals by which this transcription factor regulates the osteogenic differentiation program in MSCs. PMID:20564211

  6. Setleis syndrome due to inheritance of the 1p36.22p36.21 duplication: evidence for lack of penetrance.

    PubMed

    Lee, Beom Hee; Kasparis, Christos; Chen, Brenden; Mei, Hui; Edelmann, Lisa; Moss, Celia; Weaver, David D; Desnick, Robert J

    2015-11-01

    Setleis syndrome, focal facial dermal dysplasia type III (FFDD3, MIM #227260), is characterized by scar-like bitemporal lesions and other ocular and facial dysmorphic features. The syndrome results from recessive mutations in the TWIST2 gene, encoding a basic helix-loop-helix transcription factor or de novo genomic duplication or triplication, which include 1.3?Mb at 1p36.22p36.21, or other yet undefined lesions, emphasizing the syndrome's genetic heterogeneity. Recently, three patients were reported with 1p36.22p36.21 duplications/triplication that had the characteristic FFDD3 features and developmental delay or intellectual disabilities. Here, we describe a male with this microduplication, and the typical FFDD3 phenotype, but normal intelligence. Notably, his duplication was inherited from his father who did not have any FFDD3 manifestations, indicating lack of penetrance of the 1p36.22p36.21 microduplication. These findings emphasize phenotypic heterogeneity of the 1p36.22p36.21 copy number variant and the importance of screening the parents of patients with the 1p36.22p36.21 copy number variant to determine whether the duplication/triplication is de novo or inherited, for informed reproductive and genetic counseling. PMID:26311541

  7. Is overexpression of TWIST, a transcriptional factor, a prognostic biomarker of head and neck carcinoma? Evidence from fifteen studies

    PubMed Central

    Zhuo, Xianlu; Luo, Huanli; Chang, Aoshuang; Li, Dairong; Zhao, Houyu; Zhou, Qi

    2015-01-01

    TWIST, a basic helix-loop-helix transcription factor, has been indicated to play a critical role in the progression of numerous malignant disorders. Published data on the significance of TWIST expression in head and neck carcinoma (HNC) risk have yielded conflicting results. Thus, we conducted a quantitative meta-analysis to obtain a precise estimate of this subject. After systematic searching and screening, a total of fifteen studies using immunohistochemistry for TWIST detection were included. The results showed that TWIST positive expression rate in HNC tissues was higher than that in normal tissues. TWIST expression might have a correlation with clinical features such as low differentiation, advanced clinical stage, presence of lymph node metastasis, distant metastasis and local recurrence (P??0.05). In addition, over-expression of TWIST was a prognostic factor for HNC (HR?=?1.92, 95% CI?=?1.13–3.25). The data suggested that TWIST might play critical roles in cancer progression and act as a prognostic factor for HNC patients. PMID:26656856

  8. Is overexpression of TWIST, a transcriptional factor, a prognostic biomarker of head and neck carcinoma? Evidence from fifteen studies.

    PubMed

    Zhuo, Xianlu; Luo, Huanli; Chang, Aoshuang; Li, Dairong; Zhao, Houyu; Zhou, Qi

    2015-01-01

    TWIST, a basic helix-loop-helix transcription factor, has been indicated to play a critical role in the progression of numerous malignant disorders. Published data on the significance of TWIST expression in head and neck carcinoma (HNC) risk have yielded conflicting results. Thus, we conducted a quantitative meta-analysis to obtain a precise estimate of this subject. After systematic searching and screening, a total of fifteen studies using immunohistochemistry for TWIST detection were included. The results showed that TWIST positive expression rate in HNC tissues was higher than that in normal tissues. TWIST expression might have a correlation with clinical features such as low differentiation, advanced clinical stage, presence of lymph node metastasis, distant metastasis and local recurrence (P??0.05). In addition, over-expression of TWIST was a prognostic factor for HNC (HR?=?1.92, 95% CI?=?1.13-3.25). The data suggested that TWIST might play critical roles in cancer progression and act as a prognostic factor for HNC patients. PMID:26656856

  9. Genetic interaction between Kit and Scl

    PubMed Central

    Lacombe, Julie; Krosl, Gorazd; Tremblay, Mathieu; Gerby, Bastien; Martin, Richard; Aplan, Peter D.; Lemieux, Sebastien

    2013-01-01

    SCL/TAL1, a tissue-specific transcription factor of the basic helix-loop-helix family, and c-Kit, a tyrosine kinase receptor, control hematopoietic stem cell survival and quiescence. Here we report that SCL levels are limiting for the clonal expansion of Kit+ multipotent and erythroid progenitors. In addition, increased SCL expression specifically enhances the sensitivity of these progenitors to steel factor (KIT ligand) without affecting interleukin-3 response, whereas a DNA-binding mutant antagonizes KIT function and induces apoptosis in progenitors. Furthermore, a twofold increase in SCL levels in mice bearing a hypomorphic Kit allele (W41/41) corrects their hematocrits and deficiencies in erythroid progenitor numbers. At the molecular level, we found that SCL and c-Kit signaling control a common gene expression signature, of which 19 genes are associated with apoptosis. Half of those were decreased in purified megakaryocyte/erythroid progenitors (MEPs) from W41/41 mice and rescued by the SCL transgene. We conclude that Scl operates downstream of Kit to support the survival of MEPs. Finally, higher SCL expression upregulates Kit in normal bone marrow cells and increases chimerism after bone marrow transplantation, indicating that Scl is also upstream of Kit. We conclude that Scl and Kit establish a positive feedback loop in multipotent and MEPs. PMID:23836559

  10. Regulation of the Mechanism of TWIST1 Transcription by BHLHE40 and BHLHE41 in Cancer Cells.

    PubMed

    Asanoma, Kazuo; Liu, Ge; Yamane, Takako; Miyanari, Yoko; Takao, Tomoka; Yagi, Hiroshi; Ohgami, Tatsuhiro; Ichinoe, Akimasa; Sonoda, Kenzo; Wake, Norio; Kato, Kiyoko

    2015-12-15

    BHLHE40 and BHLHE41 (BHLHE40/41) are basic helix-loop-helix type transcription factors that play key roles in multiple cell behaviors. BHLHE40/41 were recently shown to be involved in an epithelial-to-mesenchymal transition (EMT). However, the precise mechanism of EMT control by BHLHE40/41 remains unclear. In the present study, we demonstrated that BHLHE40/41 expression was controlled in a pathological stage-dependent manner in human endometrial cancer (HEC). Our in vitro assays showed that BHLHE40/41 suppressed tumor cell invasion. BHLHE40/41 also suppressed the transcription of the EMT effectors SNAI1, SNAI2, and TWIST1. We identified the critical promoter regions of TWIST1 for its basal transcriptional activity. We elucidated that the transcription factor SP1 was involved in the basal transcriptional activity of TWIST1 and that BHLHE40/41 competed with SP1 for DNA binding to regulate gene transcription. This study is the first to report the detailed functions of BHLHE40 and BHLHE41 in the suppression of EMT effectors in vitro. Our results suggest that BHLHE40/41 suppress tumor cell invasion by inhibiting EMT in tumor cells. We propose that BHLHE40/41 are promising markers to predict the aggressiveness of each HEC case and that molecular targeting strategies involving BHLHE40/41 and SP1 may effectively regulate HEC progression. PMID:26391953

  11. In vivo protein-DNA interactions at human DNA replication origin.

    PubMed Central

    Dimitrova, D S; Giacca, M; Demarchi, F; Biamonti, G; Riva, S; Falaschi, A

    1996-01-01

    Protein-DNA interactions were studied in vivo at the region containing a human DNA replication origin, located at the 3' end of the lamin B2 gene and partially overlapping the promoter of another gene, located downstream. DNase I treatment of nuclei isolated from both exponentially growing and nonproliferating HL-60 cells showed that this region has an altered, highly accessible, chromatin structure. High-resolution analysis of protein-DNA interactions in a 600-bp area encompassing the origin was carried out by the in vivo footprinting technique based on the ligation-mediated polymerase chain reaction. In growing HL-60 cells, footprints at sequences homologous to binding sites for known transcription factors (members of the basic-helix-loop-helix family, nuclear respiratory factor 1, transcription factor Sp1, and upstream binding factor) were detected in the region corresponding to the promoter of the downstream gene. Upon conversion of cells to a nonproliferative state, a reduction in the intensity of these footprints was observed that paralleled the diminished transcriptional activity of the genomic area. In addition to these protections, in close correspondence to the replication initiation site, a prominent footprint was detected that extended over 70 nucleotides on one strand only. This footprint was absent from nonproliferating HL-60 cells, indicating that this specific protein-DNA interaction might be involved in the process of origin activation. Images Fig. 1 Fig. 2 Fig. 3 Fig. 4 PMID:8643660

  12. A novel bHLH transcription factor PebHLH35 from Populus euphratica confers drought tolerance through regulating stomatal development, photosynthesis and growth in Arabidopsis.

    PubMed

    Dong, Yan; Wang, Congpeng; Han, Xiao; Tang, Sha; Liu, Sha; Xia, Xinli; Yin, Weilun

    2014-07-18

    Plant basic helix-loop-helix (bHLH) transcription factors (TFs) are involved in a variety of physiological processes including the regulation of plant responses to various abiotic stresses. However, few drought-responsive bHLH family members in Populus have been reported. In this study, a novel bHLH gene (PebHLH35) was cloned from Populus euphratica. Expression analysis in P. euphratica revealed that PebHLH35 was induced by drought and abscisic acid. Subcellular localization studies using a PebHLH35-GFP fusion showed that the protein was localized to the nucleus. Ectopic overexpression of PebHLH35 in Arabidopsis resulted in a longer primary root, more leaves, and a greater leaf area under well-watered conditions compared with vector control plants. Notably, PebHLH35 overexpression lines showed enhanced tolerance to water-deficit stress. This finding was supported by anatomical and physiological analyses, which revealed a reduced stomatal density, stomatal aperture, transpiration rate, and water loss, and a higher chlorophyll content and photosynthetic rate. Our results suggest that PebHLH35 functions as a positive regulator of drought stress responses by regulating stomatal density, stomatal aperture, photosynthesis and growth. PMID:24909687

  13. Basic Drafting: Book One.

    ERIC Educational Resources Information Center

    Davis, Ronald; And Others

    The first of a two-book course in drafting, this manual consists of 13 topics in the following units: introduction to drafting, general safety, basic tools and lines, major equipment, applying for a job, media, lettering, reproduction, drawing sheet layout, architect's scale usage, civil engineer's scale usage, mechanical engineer's scale usage,…

  14. Basic Electricity. Part 1.

    ERIC Educational Resources Information Center

    Kilmer, Donald C.

    A primarily illustrated introduction to the basics of electricity is presented in this guide, the first of a set of four designed for the student interested in a vocation in electrical work. This guide is intended for the first-year student and provides mostly diagrams with accompanying defintions/information in three units, each covering one of…

  15. A BASIC HINDI READER.

    ERIC Educational Resources Information Center

    HARRIS, RICHARD M.; SHARMA, RAMA NATH

    THIS TEXT WAS DESIGNED TO MEET THE SPECIFIC NEEDS OF FIRST-YEAR STUDENTS OF HINDI WITH A KNOWLEDGE OF HINDI VOCABULARY AND STRUCTURE EQUIVALENT TO THAT PRESENTED IN THE FIRST SEVEN LESSONS OF TWO WIDELY USED ELEMENTARY HINDI TEXTS, "SPOKEN AND WRITTEN HINDI" BY FAIRBANKS AND MISRA, AND "CONVERSATIONAL HINDI-URDU" BY GUMPERZ AND RUMERY. A BASIC

  16. Basic Engineer Equipment Mechanic.

    ERIC Educational Resources Information Center

    Marine Corps Inst., Washington, DC.

    This student guide, one of a series of correspondence training courses designed to improve the job performance of members of the Marine Corps, deals with the skills needed by basic engineer equipment mechanics. Addressed in the four individual units of the course are the following topics: mechanics and their tools (mechanics, hand tools, and power…

  17. Basic Internet Software Toolkit.

    ERIC Educational Resources Information Center

    Buchanan, Larry

    1998-01-01

    Once schools are connected to the Internet, the next step is getting network workstations configured for Internet access. This article describes a basic toolkit comprising software currently available on the Internet for free or modest cost. Lists URLs for Web browser, Telnet, FTP, file decompression, portable document format (PDF) reader,…

  18. Ethanol Basics (Fact Sheet)

    SciTech Connect

    Not Available

    2015-01-01

    Ethanol is a widely-used, domestically-produced renewable fuel made from corn and other plant materials. More than 96% of gasoline sold in the United States contains ethanol. Learn more about this alternative fuel in the Ethanol Basics Fact Sheet, produced by the U.S. Department of Energy's Clean Cities program.

  19. Teaching Basic Caregiver Skills.

    ERIC Educational Resources Information Center

    Schenk, Susan, Ed.; Harrah, Doris, Ed.

    This instructor's guide provides materials for a nursing skills course designed to teach basic home nursing skills to families who plan to care for a chronically ill or elderly family member at home. It may be taught by a registered nurse with knowledge of all areas or by a team, with each instructor concentrating on his/her area of expertise.…

  20. FULA BASIC COURSE.

    ERIC Educational Resources Information Center

    SWIFT, LLOYD B.; AND OTHERS

    THIS BEGINNING COURSE IS AN INTRODUCTION TO FULA (KNOWN VARIOUSLY AS FULANI, FUL, PEUL, OR PHEUL), A NIGER-CONGO LANGUAGE SPOKEN THROUGHOUT THE GRASSLAND AREAS OF WEST AFRICA FROM THE ATLANTIC TO CAMEROUN. THE TEXT IS ONE OF A SERIES OF SHORT BASIC COURSES IN SELECTED AFRICAN LANGUAGES BEING PREPARED BY THE FOREIGN SERVICE INSTITUTE. IT IS…

  1. Projectable Basic Electronics Kit.

    ERIC Educational Resources Information Center

    H'ng, John; And Others

    1982-01-01

    Outlines advantages derived from constructing and using a Projectable Basic Electronics Kit and provides: (1) list of components; (2) diagrams of 10 finished components (resistor; capacitor; diode; switch; bulb; transistor; meter; variable capacitor; coil; connecting terminal); and (3) diode and transistor activities. (JN)

  2. CALCULUS II BASIC INFORMATION

    E-print Network

    Bloch, Ethan

    (Math 141), that is, basic differentiation and integration, through u-substitution. This course continues the study of integration begun in Calculus I, and introduces derivatives and integrals for functions of several variables. Topics covered include techniques of integration, l'Hopital's rule, improper

  3. Basic Media in Education.

    ERIC Educational Resources Information Center

    Harrell, John

    Intended as a guide to the use of different media for use in the classroom, this document demonstrates alternative approaches that may be taken to depicting and communicating images and concepts to others. Some basic tools and materials--including a ruler, matte knife, rubber cement, stapler, felt-tip pens, paint brushes, and lettering pens--are…

  4. Body Basics Library

    MedlinePLUS

    ... this medical library to find out about basic human anatomy, how it all functions, and what happens when things go wrong. Blood Bones, Muscles, and Joints Brain and Nervous System Digestive System Endocrine System Eyes Female Reproductive System Heart and Circulatory System Immune ...

  5. CALCULUS II BASIC INFORMATION

    E-print Network

    Bloch, Ethan

    . 11:00-12:00, 4:40-5:40 ·Thur. 2:30-4:00 Text ·Stewart, James, "Calculus: Concepts and Contexts," 4ndMATH 142A CALCULUS II FALL 2013 BASIC INFORMATION Class ·Mon. 10:10-11:30 ·Wed. 10., Dec. 18 #12;WHAT IS MATH 142 ·This course is the second semester of Bard's calculus sequence

  6. Basic Nuclear Physics.

    ERIC Educational Resources Information Center

    Bureau of Naval Personnel, Washington, DC.

    Basic concepts of nuclear structures, radiation, nuclear reactions, and health physics are presented in this text, prepared for naval officers. Applications to the area of nuclear power are described in connection with pressurized water reactors, experimental boiling water reactors, homogeneous reactor experiments, and experimental breeder…

  7. Internet Training: The Basics.

    ERIC Educational Resources Information Center

    Gallo, Gail; Wichowski, Chester P.

    This paper outlines the basic information teachers need to know to use the World Wide Web for research and communication, using Netscape 3.04. Topics covered include the following: what is the World Wide Web?; what is a browser?; accessing the Web; moving around a web document; the Uniform Resource Locator (URL); Bookmarks; saving and printing a…

  8. Assessing Basic Fact Fluency

    ERIC Educational Resources Information Center

    Kling, Gina; Bay-Williams, Jennifer M.

    2014-01-01

    In this article, the authors share a variety of ways to formatively assess basic fact fluency. The define fluency, raise some issues related to timed testing, and then share a collection of classroom-tested ideas for authentic fact fluency assessment. This article encourages teachers to try a variety of alternative assessments from this sampling,…

  9. HINDI BASIC COURSE.

    ERIC Educational Resources Information Center

    HARTER, J. MARTIN; AND OTHERS

    THIS TEXT PROVIDES AN INTRODUCTORY COURSE IN HINDI, A DIALECT OF WEST PAKISTAN AND NORTHERN INDIA. PRIMARY EMPHASIS IN THE COURSE LIES IN THE USE OF BASIC SENTENCES (BRIEF CONVERSATIONS) WHICH INTRODUCE VOCABULARY AND GRAMMAR STRUCTURES. A NUMBER OF APPROPRIATE EXERCISES OR DRILLS ARE PROVIDED FOR EACH GROUP OF SENTENCES. A PRONUNCIATION WORDLIST…

  10. Basic Electronics II.

    ERIC Educational Resources Information Center

    Willison, Neal A.; Shelton, James K.

    Designed for use in basic electronics programs, this curriculum guide is comprised of 15 units of instruction. Unit titles are Review of the Nature of Matter and the P-N Junction, Rectifiers, Filters, Special Semiconductor Diodes, Bipolar-Junction Diodes, Bipolar Transistor Circuits, Transistor Amplifiers, Operational Amplifiers, Logic Devices,…

  11. Focus on Basics, 1998.

    ERIC Educational Resources Information Center

    Focus on Basics, 1998

    1998-01-01

    This volume contains the four 1998 quarterly issues of this newsletter that present best practices, current research on adult learning and literacy, and information on how research is used by adult basic education teachers, counselors, program administrators, and policy makers. The following are among the major articles included: "Power, Literacy,…

  12. MONITORING DROUGHT Basic Climatology

    E-print Network

    MONITORING DROUGHT Basic Climatology Colorado Climate Center Funding provided by NOAA Sectoral Applications Research Project #12;DEFINING DROUGHT #12;First off, just what is drought? Define a tornado the same for drought #12;First off, just what is drought? Precipitation deficits? Soil moisture

  13. Basic Pneumatics. Instructor's Guide.

    ERIC Educational Resources Information Center

    Fessehaye, Michael

    This instructor's guide is designed for use by industrial vocational teachers in teaching a course on basic pneumatics. Covered in the individual units are the following topics: an introduction to pneumatics (including the operation of a service station hoist); fundamentals and physical laws; air compressors (positive displacement compressors;…

  14. Turkish Basic Course.

    ERIC Educational Resources Information Center

    Defense Language Inst., Washington, DC.

    These 14 volumes of the Defense Language Institute's basic course in Turkish consist of 112 lesson units designed to train native English language speakers to Level 3 proficiency in comprehending, speaking, reading, and writing Turkish. (Native-speaker fluency is Level 5.) An introduction to the sound system, vowel harmony, and syllable division…

  15. Swahili Basic Course.

    ERIC Educational Resources Information Center

    Defense Language Inst., Washington, DC.

    This basic audiolingual course in standard Swahili appears in six volumes, Lesson Units 1-56. Units consist of a "blueprint" prefatory page outlining the phonological, morphological, and syntactic structures and new vocabulary to be presented; perception drills; Swahili dialog with cartoon guides and English translation; pattern and recombination…

  16. Korean Basic Course.

    ERIC Educational Resources Information Center

    Defense Language Inst., Washington, DC.

    These 11 volumes of the Korean Basic Course comprise 112 lesson units designed to train native English language speakers to Level 3 proficiency in comprehension and speaking and Level 2 proficiency in reading and writing Korean. (Level 5 on this scale is native-speaker level.) Intended for classroom use in the Defense Language Institute intensive…

  17. Basics of Online Searching.

    ERIC Educational Resources Information Center

    Meadow, Charles T.; Cochrane, Pauline (Atherton)

    Intended to teach the principles of interactive bibliographic searching to those with little or no prior experience, this textbook explains the basic elements of online information retrieval and compares the major database search systems. Its chapters address (1) relevant definitions and vocabulary; (2) the conceptual facets of database searching,…

  18. Basic lubrication equations

    NASA Technical Reports Server (NTRS)

    Hamrock, B. J.; Dowson, D.

    1981-01-01

    Lubricants, usually Newtonian fluids, are assumed to experience laminar flow. The basic equations used to describe the flow are the Navier-Stokes equation of motion. The study of hydrodynamic lubrication is, from a mathematical standpoint, the application of a reduced form of these Navier-Stokes equations in association with the continuity equation. The Reynolds equation can also be derived from first principles, provided of course that the same basic assumptions are adopted in each case. Both methods are used in deriving the Reynolds equation, and the assumptions inherent in reducing the Navier-Stokes equations are specified. Because the Reynolds equation contains viscosity and density terms and these properties depend on temperature and pressure, it is often necessary to couple the Reynolds with energy equation. The lubricant properties and the energy equation are presented. Film thickness, a parameter of the Reynolds equation, is a function of the elastic behavior of the bearing surface. The governing elasticity equation is therefore presented.

  19. Basics of Biosafety

    NASA Technical Reports Server (NTRS)

    Wong, Willy

    2009-01-01

    This slide presentation reviews the basics of biosafety and the importance of assuring proper biosafety practices. The objectives of the presentation are to review regulations about biosafety, and the different biosafety levels; the biosafety facilities at Johnson Space Center; the usage and maintenance of the biosafety cabinet, the proper methods to handle biologically hazardous materials upon exposure, and the methods of cleanup in the event of a spill, and the training requirements that are mandated for personnel handling biologically hazardous materials.

  20. The Basic Anaesthesia Machine

    PubMed Central

    Gurudatt, CL

    2013-01-01

    After WTG Morton's first public demonstration in 1846 of use of ether as an anaesthetic agent, for many years anaesthesiologists did not require a machine to deliver anaesthesia to the patients. After the introduction of oxygen and nitrous oxide in the form of compressed gases in cylinders, there was a necessity for mounting these cylinders on a metal frame. This stimulated many people to attempt to construct the anaesthesia machine. HEG Boyle in the year 1917 modified the Gwathmey's machine and this became popular as Boyle anaesthesia machine. Though a lot of changes have been made for the original Boyle machine still the basic structure remains the same. All the subsequent changes which have been brought are mainly to improve the safety of the patients. Knowing the details of the basic machine will make the trainee to understand the additional improvements. It is also important for every practicing anaesthesiologist to have a thorough knowledge of the basic anaesthesia machine for safe conduct of anaesthesia. PMID:24249876

  1. Basic facts about Venus

    NASA Technical Reports Server (NTRS)

    Colin, L.

    1983-01-01

    Because of the disturbing influence of the earth's atmosphere on terrestrial and airborne telescopy, radiometry, thermal mapping, spectroscopy, polarimetry and radar astronomy of Venus, major improvements in the body of theory concerning that planet, began with the Mariner 2 planetary exploration program in 1962. The effect of spacecraft exploration culminated with the influx of data yielded by the Pioneer Venus and Venera 11 and 12 missions of 1978. Attention is presently given to the quantitative enhancement of widely accepted, basic facts about Venus that has resulted from the analysis of space probe data, together with an overview of the major features of past and planned planetary missions.

  2. Basic space payload fastener

    NASA Technical Reports Server (NTRS)

    Vranish, J. M.; Gorevan, Stephen

    1995-01-01

    A new basic space fastener has been developed and tested by the GSFC. The purposes of this fastener are to permit assembly and servicing in space by astronauts and/or robots and to facilitate qualification of payloads on Earth prior to launch by saving time and money during the systems integration and component testing and qualification processes. The space fastener is a rework of the basic machine screw such that crossthreading is impossible; it is self-locking and will not work its way out during launch (vibration proof); it will not wear out despite repeated use; it occupies a small foot print which is comparable to its machine screw equivalent, and it provides force and exhibits strength comparable to its machine screw equivalent. Construction is ultra-simple and cost effective and the principle is applicable across the full range of screw sizes ranging from a #10 screw to 2.5 cm (1 in) or more. In this paper, the fastener principles of operation will be discussed along with test results and construction details. The new fastener also has considerable potential in the commercial sector. A few promising applications will be presented.

  3. Basic and clinical immunology

    NASA Technical Reports Server (NTRS)

    Chinen, Javier; Shearer, William T.

    2003-01-01

    Progress in immunology continues to grow exponentially every year. New applications of this knowledge are being developed for a broad range of clinical conditions. Conversely, the study of primary and secondary immunodeficiencies is helping to elucidate the intricate mechanisms of the immune system. We have selected a few of the most significant contributions to the fields of basic and clinical immunology published between October 2001 and October 2002. Our choice of topics in basic immunology included the description of T-bet as a determinant factor for T(H)1 differentiation, the role of the activation-induced cytosine deaminase gene in B-cell development, the characterization of CD4(+)CD25(+) regulatory T cells, and the use of dynamic imaging to study MHC class II transport and T-cell and dendritic cell membrane interactions. Articles related to clinical immunology that were selected for review include the description of immunodeficiency caused by caspase 8 deficiency; a case series report on X-linked agammaglobulinemia; the mechanism of action, efficacy, and complications of intravenous immunoglobulin; mechanisms of autoimmunity diseases; and advances in HIV pathogenesis and vaccine development. We also reviewed two articles that explore the possible alterations of the immune system caused by spaceflights, a new field with increasing importance as human space expeditions become a reality in the 21st century.

  4. Introduction Basics of gravity theory

    E-print Network

    Visser, Matt

    Introduction Basics of gravity theory Actions and Field Equations Phenomenology Discussion;Introduction Basics of gravity theory Actions and Field Equations Phenomenology Discussion and Conclusions Einstein completes the General Theory of Relativity (GR). The theory explains Mercury's precession. 1919

  5. Responding to the Basics Movement.

    ERIC Educational Resources Information Center

    Davis, James E., Ed.; And Others

    1979-01-01

    The 17 articles in this journal issue focus on a response to the basics movement. Specific topics covered in the articles include the following: a definition of literacy, the meaning of the basics, the back-to-the-basics movement from a historical-linguistic perspective, behavior modification and the teaching of English composition, developing…

  6. Basic properties and variability

    NASA Technical Reports Server (NTRS)

    Querci, Francois R.

    1987-01-01

    Giant and supergiant M, S, and C stars are discussed in this survey of research. Basic properties as determined by spectra, chemical composition, photometry, or variability type are discussed. Space motions and space distributions of cool giants are described. Distribution of these stars in our galaxy and those nearby is discussed. Mira variables in particular are surveyed with emphasis on the following topics: (1) phase lag phenomenon; (2) Mira light curves; (3) variations in color indices; (4) determination of multiple periods; (5) correlations between quantities such as period length, light-curve shape, infrared (IR) excess, and visible and IR color diagram; (6) semiregular (SR) variables and different time scales in SR light variations; (7) irregular variable Lb and Lc stars; (8) different time-scale light variations; (9) hydrogen-deficient carbon (HdC) stars, in particular RCB stars; and (10) irreversible changes and rapid evolution in red variable stars.

  7. BasicODT

    Energy Science and Technology Software Center (ESTSC)

    2007-09-25

    BasicODT is a Monte Carlo simulation that numerically implements One-Dimensional Turbulence (ODT), a stochastic model of turbulent flow that was developed by the author of the code. This code is set up to simulate channel flow, which is the flow between two parallel flat walls driven by a fixed pressure gradient, with no-slip conditions at the walls. The code writes output files containing flow statistics gathered during the simulation. The code is accompanied by documentationmore »that explains how ODT modeling principles are numerically implemented within the code. The code and documentation are intended as an introduction to ODT for use as a learning tool for people who are unfamiliar with the model and its numerical implementation. ODT is fully described in published literature.« less

  8. Lyme Disease Treatment (Beyond the Basics)

    MedlinePLUS

    ... information: Lyme disease (The Basics) Patient information: Rocky Mountain spotted fever (The Basics) Beyond the Basics — Beyond ... information: Lyme disease (The Basics) Patient information: Rocky Mountain spotted fever (The Basics) Prevention of Lyme disease ...

  9. Dizziness and Vertigo (Beyond the Basics)

    MedlinePLUS

    ... Meniere disease (The Basics) Patient information: Vestibular schwannoma (acoustic neuroma) (The Basics) Beyond the Basics — Beyond the ... of dizziness) (The Basics) Patient information: Vestibular schwannoma (acoustic neuroma) (The Basics) Treatment of vertigo Vestibular migraine ...

  10. PEROXISOME PROLIFERATOR-ACTIVATED RECEPTOR? (PPAR?) AGONISTS DIFFERENTIALLY REGULATE INHIBITOR OF DNA BINDING (ID2) EXPRESSION IN RODENTS AND HUMAN CELLS

    EPA Science Inventory

    Abstract Inhibitor of DNA binding (Id2) is a member of the helix-loop-helix (HLH) transcription factor family whose members play important roles in cell differentiation and proliferation. Id2 has been linked to the development of cardiovascular diseases since thiazolidinediones,...

  11. IMMUNOHISTOCHEMICAL DOUBLE-STAINING FOR AH RECEPTOR AND ARNT IN HUMAN EMBRYONIC PALATAL SHELVES

    EPA Science Inventory

    The aryl hydrocarbon receptor (AhR) and the AhR nuclear translocation protein (ARNT) are helix-loop-helix (HLH) proteins involved in transcriptional regulation. olycyclic aromatic halogenated chemicals, of which 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) is the most potent, bind ...

  12. Basic concepts of epigenetics

    PubMed Central

    Mazzio, Elizabeth A

    2012-01-01

    Through epigenetic modifications, specific long-term phenotypic consequences can arise from environmental influence on slowly evolving genomic DNA. Heritable epigenetic information regulates nucleosomal arrangement around DNA and determines patterns of gene silencing or active transcription. One of the greatest challenges in the study of epigenetics as it relates to disease is the enormous diversity of proteins, histone modifications and DNA methylation patterns associated with each unique maladaptive phenotype. This is further complicated by a limitless combination of environmental cues that could alter the epigenome of specific cell types, tissues, organs and systems. In addition, complexities arise from the interpretation of studies describing analogous but not identical processes in flies, plants, worms, yeast, ciliated protozoans, tumor cells and mammals. This review integrates fundamental basic concepts of epigenetics with specific focus on how the epigenetic machinery interacts and operates in continuity to silence or activate gene expression. Topics covered include the connection between DNA methylation, methyl-CpG-binding proteins, transcriptional repression complexes, histone residues, histone modifications that mediate gene repression or relaxation, histone core variant stability, H1 histone linker flexibility, FACT complex, nucleosomal remodeling complexes, HP1 and nuclear lamins. PMID:22395460

  13. PHYSICS W3003: MATHEMATICAL BASICS 1. Differential equation basics

    E-print Network

    Millis, Andrew

    PHYSICS W3003: MATHEMATICAL BASICS 1. Differential equation basics 1.1. Example. Newton's equation for the motion of a particle, (1) m d2R(t) dt2 = F(R, t) is an example of a differential equation, an equation on time. 1.2. Classification of Differential Equations. 1.2.1. Ordinary vs partial differential equations

  14. The Humanities and Basic Skills.

    ERIC Educational Resources Information Center

    Karolides, Nicholas J., Ed.

    1984-01-01

    The articles in this journal issue present a rationale and methods for using elements of the humanities to teach remedial reading and writing. The titles of the articles and their authors are as follows: (1) "The Humanities and Basic Skills Project" (Nan Dougherty); (2) "The Humanities and Basic Skills" (Robert L. Horn); (3) "Beyond Fragmentation;…

  15. Are Basic Writers Cognitively Deficient?

    ERIC Educational Resources Information Center

    Martinez, Joseph G. R.; Martinez, Nancy C.

    Researchers of writing ability have often applied the developmental schemes of William Perry, Lev Vygotsky, and Jean Piaget in describing basic writers. As a result, some researchers have concluded that basic writers think well below the formal-operations or true concept-formation stage of cognitive development. To investigate the theory that…

  16. Czech Basic Course: Verb List.

    ERIC Educational Resources Information Center

    Stoner, William; Vit, Karel V.

    This compilation of verbs, intended for students of the Defense Language Institute (DLI) Basic Course, provides brief definitions for each entry. No sentence examples are included. The text is intended to serve as a compact reference and study aid. Examples are selected from the Basic Course and the DLI Czech-English Dictionary. Entries are listed…

  17. BASIC Instructional Program: System Documentation.

    ERIC Educational Resources Information Center

    Dageforde, Mary L.

    This report documents the BASIC Instructional Program (BIP), a "hands-on laboratory" that teaches elementary programming in the BASIC language, as implemented in the MAINSAIL language, a machine-independent revision of SAIL which should facilitate implementation of BIP on other computing systems. Eight instructional modules which make up the BIP…

  18. Children and Their Basic Needs.

    ERIC Educational Resources Information Center

    Prince, Debra Lindsey; Howard, Esther M.

    2002-01-01

    Describes obstacles presented by poverty in the fulfillment of the basic needs of children. Individually addresses Maslow's five basic needs with regard to children reared in poverty: (1) physiological needs; (2) safety needs; (3) belonging and love needs; (4) self-esteem needs; and (5) self-actualization needs. (Author/SD)

  19. Basic Principles for Adult Education.

    ERIC Educational Resources Information Center

    Office of Vocational and Adult Education, Washington, DC. Div. of Adult Education.

    A basic set of principles for adult education reflects what should be found in each state and local program. First, basic skills should be mastered by all students. Second, course content should be directly related to learner, labor market, and community needs. Third, partnership efforts should be expanded and strengthened. Fourth, programs must…

  20. Coding theory basics Toric codes

    E-print Network

    Little, John B.

    Coding theory basics Toric codes Tools from the toric world Higher-dimensional polytopes and Vandermonde matrices Toric Varieties in Error-Control Coding Theory Math in the Mountains Tutorial John B. Little Toric Varieties in Coding Theory #12;Coding theory basics Toric codes Tools from the toric world

  1. Health Care Basics: Choosing the

    E-print Network

    Li, Mo

    2012 Health Care Basics: Choosing the Best Option for Your Health "Creating A More Educated Georgia" #12;Health Care Basics 2 Medical Options for Plan Year 2012 The University System of Georgia's Plan of Regents will offer the following health care options: · Blue Choice HMO · Kaiser Permanente HMO · HSA Open

  2. Chinese-Cantonese Basic Course.

    ERIC Educational Resources Information Center

    Defense Language Inst., Washington, DC.

    This nine-volume basic course in Cantonese Chinese is designed for 47 weeks of intense audiolingual instruction. The first book of the series introduces the pronunciation, with emphasis on the tone system, and the basic aspects of the grammar. Also introduced in this volume is the romanization system used in this series (the U.S. Army Language…

  3. DIY BASICS CHECKLIST DRIPS AND LEAKS

    E-print Network

    Peters, Richard

    DIY BASICS CHECKLIST DRIPS AND LEAKS Watercancauseseriousdamage- oftenunseen'tdrillintomortarbetweenbricks. #12;DIY BASICS CHECKLIST Location Twopeoplemakethisamuch easierjob. Cutasheetofpapertothesize

  4. NANOMATERIALS FOR PROTEIN MEDIATED THERAPY AND DELIVERY

    PubMed Central

    Barry, John N.; Vertegel, Alexey A.

    2014-01-01

    There has been a significant amount of research done on liposomes and nanoparticles as drug carriers for protein drugs. Proteins and enzymes have been used both as targeting moieties and for their therapeutic potential. High specificity and rapid reaction rates make proteins and enzymes excellent candidates for therapeutic treatment, but some limitations exist. Many of these limitations can be addressed by a well studied nanotechnology based delivery system. Such a system can provide a medium for delivery, stabilization of the drugs, and enable site specific accumulation of drugs. Nanomedicines such as these have great potential to revolutionize the pharmaceutical industry and improve healthcare worldwide. PMID:25414730

  5. The basic aerodynamics of floatation

    SciTech Connect

    Davies, M.J.; Wood, D.H.

    1983-09-01

    The original derivation of the basic theory governing the aerodynamics of both hovercraft and modern floatation ovens, requires the validity of some extremely crude assumptions. However, the basic theory is surprisingly accurate. It is shown that this accuracy occurs because the final expression of the basic theory can be derived by approximating the full Navier-Stokes equations in a manner that clearly shows the limitations of the theory. These limitations are used in discussing the relatively small discrepancies between the theory and experiment, which may not be significant for practical purposes.

  6. Basic networks: definition and applications.

    PubMed

    Marín, Ignacio; Hoyas, Sergio

    2009-05-01

    We define basic networks as the undirected subgraphs with minimal number of units in which the distances (geodesics, minimal path lengths) among a set of selected nodes, which we call seeds, in the original graph are conserved. The additional nodes required to draw the basic network are called connectors. We describe a heuristic strategy to find the basic networks of complex graphs. We also show how the characterization of these networks may help to obtain relevant biological information from highly complex protein-protein interaction data. PMID:19490867

  7. James P. Hobert Basic Information

    E-print Network

    Wu, Dapeng Oliver

    James P. Hobert Basic Information Mailing Address: Telephone Numbers: Internet: Department of Multivariate Analysis 112: 108-116. Khare, K. and Hobert, J. P. (2011). A spectral analytic comparison of trace

  8. Diabetic Neuropathy (Beyond the Basics)

    MedlinePLUS

    ... of Use ©2016 UpToDate, Inc. Patient information: Diabetic neuropathy (Beyond the Basics) Author Eva L Feldman, MD, ... This topic last updated: Dec 27, 2013. DIABETIC NEUROPATHY OVERVIEW — Neuropathy is the medical term for nerve ...

  9. Brain Basics: Know Your Brain

    MedlinePLUS

    ... EPUB version (2 MB) MOBI version (4 MB) Brain Basics: Know Your Brain Request free mailed brochure Table of Contents Introduction ... dysfunctional. Image 1 < top > The Architecture of the Brain The brain is like a committee of experts. ...

  10. Chronic Pancreatitis (Beyond the Basics)

    MedlinePLUS

    ... of Use ©2016 UpToDate, Inc. Patient information: Chronic pancreatitis (Beyond the Basics) Author Steven D Freedman, MD, ... 2015. | This topic last updated: Jun 25, 2013. PANCREATITIS OVERVIEW — The pancreas is an organ in the ...

  11. Acute Pancreatitis (Beyond the Basics)

    MedlinePLUS

    ... of Use ©2016 UpToDate, Inc. Patient information: Acute pancreatitis (Beyond the Basics) Author Santhi Swaroop Vege, MD ... Consultant/Advisory Boards: CalciMedica [Drug development for acute pancreatitis]. J Thomas Lamont, MD Nothing to disclose. Shilpa ...

  12. Plants, Animals and Basic Skills.

    ERIC Educational Resources Information Center

    Pheasant, Robert

    2000-01-01

    Countrystart is a class in which students work with plants and animals, providing numerous opportunities to integrate basic skills teaching. The practical subject area becomes the vehicle to develop other skills needed by students. (JOW)

  13. Office of Basic Energy Sciences

    NASA Astrophysics Data System (ADS)

    1991-09-01

    Basic research is an important investment in the future and will help the U.S. maintain and enhance its economic strength. The U.S. Department of Energy Office of Basic Energy Sciences (BES) basic research activities, carried out mainly in universities and Department of Energy (DOE) laboratories, are critical to the Nation's leadership in science, for training future scientists, and to fortify the Nation's foundations for social and economic well-being. Attainment of the national goals (energy self-sufficiency, improved health and quality of life for all, economic growth, national security) depends on both technological research achievements and the ability to exploit them rapidly. Basic research is a necessary element for technology development and economic growth. This report presents the Department of Energy's Office of Basic Energy Sciences program. The BES mission is to develop understanding and to stimulate innovative thinking needed to fortify the Department's missions. The program has two distinct interrelated parts: research and facilities operations and development. In the pursuit of forefront research results, BES designs, builds and operates certain large, complex advanced scientific facilities such as neutron sources and synchrotron radiation sources. These facilities not only provide BES with unique instruments, but these instruments are also made available to all qualified users, even those not supported by BES. Thus, the facilities actually leverage a great deal more research from the national effort. The BES program conducts basic research that will most likely help the Nation's long-term energy goals. BES implements a broad strategy for conducting basic research and contributes strongly towards national energy goals and to national goals of maintaining and enhancing scientific leadership, technological innovation, and economic strength.

  14. Basic Communication Course Annual. Volume 5.

    ERIC Educational Resources Information Center

    Hugenberg, Lawrence W., Ed.

    This volume of an annual collection of essays relating to instruction in the basic communication course presents 1992 Speech Communication Association Basic Course Committee award winning papers, articles on teaching assistants in the basic course, approaches to teaching in the basic course, research on the basic course, and a commentary. Essays…

  15. Involvement of transcription factor encoded by the mouse mi locus (MITF) in apoptosis of cultured mast cells induced by removal of interleukin-3.

    PubMed Central

    Tsujimura, T.; Hashimoto, K.; Morii, E.; Tunio, G. M.; Tsujino, K.; Kondo, T.; Kanakura, Y.; Kitamura, Y.

    1997-01-01

    Mast cells develop when spleen cells of mice are cultured in the medium containing interleukin (IL)-3. Cultured mast cells (CMCs) show apoptosis when they are incubated in the medium without IL-3. We obtained CMCs from tg/tg mice that did not express the transcription factor encoded by the mi gene (MITF) due to the integration of a transgene at its 5' flanking region. MITF is a member of the basic-helix-loop-helix-leucine zipper (bHLH-Zip) protein family of transcription factors. We investigated the effect of MITF on the apoptosis of CMCs after removal of IL-3. When cDNA encoding normal MITF ((+)-MITF) was introduced into tg/tg CMCs with the retroviral vector, the apoptosis of tg/tg CMCs was significantly accelerated. The mutant mi allele represents a deletion of an arginine at the basic domain of MITF. The apoptosis of tg/tg CMCs was not accelerated by the introduction of cDNA encoding mi-MITF. The overexpression of (+)-MITF was not prerequisite to the acceleration of the apoptosis, as the apoptotic process proceeded faster in +/+ CMCs than in mi/mi CMCs. The Ba/F3 lymphoid cell line is also dependent on IL-3, and Ba/F3 cells show apoptosis after removal of IL-3. The c-myc gene encodes another transcription factor of the bHLH-Zip family, and the overexpression of the c-myc gene accelerated the apoptosis of Ba/F3 cells. However, the overexpression of (+)-MITF did not accelerate the apoptosis of Ba/F3 cells. The (+)-MITF appeared to play some roles for the acceleration of the apoptosis specifically in the mast cell lineage. Images Figure 2 Figure 3 Figure 4 Figure 5 Figure 6 Figure 7 PMID:9327738

  16. Basics.

    ERIC Educational Resources Information Center

    Instructor, 1982

    1982-01-01

    Recommended activities include: (1) etymology exercises for elementary school students; (2) a search for information about Alexander the Great; (3) monthly inspections of the school yard to observe environmental changes; and (4) an art history unit on Cro-Magnon cave drawings. An interdisciplinary unit on transportation is included. (PP)

  17. Basic research for environmental restoration

    SciTech Connect

    Not Available

    1990-12-01

    The Department of Energy (DOE) is in the midst of a major environmental restoration effort to reduce the health and environmental risks resulting from past waste management and disposal practices at DOE sites. This report describes research needs in environmental restoration and complements a previously published document, DOE/ER-0419, Evaluation of Mid-to-Long Term Basic Research for Environmental Restoration. Basic research needs have been grouped into five major categories patterned after those identified in DOE/ER-0419: (1) environmental transport and transformations; (2) advanced sampling, characterization, and monitoring methods; (3) new remediation technologies; (4) performance assessment; and (5) health and environmental effects. In addition to basic research, this document deals with education and training needs for environmental restoration. 2 figs., 6 tabs.

  18. The basic aerodynamics of floatation

    NASA Astrophysics Data System (ADS)

    Davies, M. J.; Wood, D. H.

    1983-09-01

    It is pointed out that the basic aerodynamics of modern floatation ovens, in which the continuous, freshly painted metal strip is floated, dried, and cured, is the two-dimensional analog of that of hovercraft. The basic theory for the static lift considered in connection with the study of hovercraft has had spectacular success in describing the experimental results. This appears surprising in view of the crudity of the theory. The present investigation represents an attempt to explore the reasons for this success. An outline of the basic theory is presented and an approach is shown for deriving the resulting expressions for the lift from the full Navier-Stokes equations in a manner that clearly indicates the limitations on the validity of the expressions. Attention is given to the generally good agreement between the theory and the axisymmetric (about the centerline) results reported by Jaumotte and Kiedrzynski (1965).

  19. Basic Operational Robotics Instructional System

    NASA Technical Reports Server (NTRS)

    Todd, Brian Keith; Fischer, James; Falgout, Jane; Schweers, John

    2013-01-01

    The Basic Operational Robotics Instructional System (BORIS) is a six-degree-of-freedom rotational robotic manipulator system simulation used for training of fundamental robotics concepts, with in-line shoulder, offset elbow, and offset wrist. BORIS is used to provide generic robotics training to aerospace professionals including flight crews, flight controllers, and robotics instructors. It uses forward kinematic and inverse kinematic algorithms to simulate joint and end-effector motion, combined with a multibody dynamics model, moving-object contact model, and X-Windows based graphical user interfaces, coordinated in the Trick Simulation modeling environment. The motivation for development of BORIS was the need for a generic system for basic robotics training. Before BORIS, introductory robotics training was done with either the SRMS (Shuttle Remote Manipulator System) or SSRMS (Space Station Remote Manipulator System) simulations. The unique construction of each of these systems required some specialized training that distracted students from the ideas and goals of the basic robotics instruction.

  20. Principles for Working with Basic Writers.

    ERIC Educational Resources Information Center

    Thorpe, Dean

    1994-01-01

    Describes the various "affective filters" that inhibit basic writers from learning to write. Suggests principles for avoiding such inhibitions among basic writers. Claims that such principles are an effective way of fostering writing development among basic writers. (HB)

  1. Basics on Genes and Genetic Disorders

    MedlinePLUS

    ... Losing Weight Safely The Basics on Genes and Genetic Disorders KidsHealth > Teens > Body > Health Basics > The Basics ... endless number of possible combinations! Continue Genes and Heredity Heredity is the passing of genes from one ...

  2. Vitamin D Deficiency (Beyond the Basics)

    MedlinePLUS

    ... for bone health (Beyond the Basics) Patient information: Breastfeeding guide (Beyond the Basics) Patient information: Starting solid foods during infancy (Beyond the Basics) Professional level information — Professional level articles are designed to ...

  3. Cosmic Particle Acceleration: Basic Issues

    E-print Network

    T. W. Jones

    2000-12-22

    Cosmic-rays are ubiquitous, but their origins are surprisingly difficult to understand. A review is presented of some of the basic issues common to cosmic particle accelerators and arguments leading to the likely importance of diffusive shock acceleration as a general explanation. The basic theory of diffusive shock acceleration is outlined, followed by a discussion of some of the key issues that still prevent us from a full understanding of its outcomes. Some recent insights are mentioned at the end that may help direct ultimate resolution of our uncertainties.

  4. Transient Ischemic Attack (Beyond the Basics)

    MedlinePLUS

    ... smoking (Beyond the Basics)" ) ? Treating high cholesterol and lipids (see "Patient information: High cholesterol and lipids (hyperlipidemia) (Beyond the Basics)" ) Antiplatelet therapy — Platelets are ...

  5. Basic Mechanisms of the Epilepsies.

    ERIC Educational Resources Information Center

    Jasper, Herbert H., Ed.; And Others

    A collection of highly technical scientific articles by international basic and clinical neuroscientists constitutes a review of their knowledge of the brain and nervous system, particularly the aspects related to loss of brain function control and its explosive discharges which cause epileptic seizures. Anatomy, biophysics, biochemistry, and…

  6. Basic Skills in Asian Studies.

    ERIC Educational Resources Information Center

    Hantula, James

    This publication contains field tested learning activities which will help secondary students develop basic skills while learning about Asian history, culture, and geography. The activities can be used or easily adapted by teachers in any Asian studies course. The publication is organized by the skills taught. These are: reading; applying…

  7. Foraging Behavior Some Basic Ideas

    E-print Network

    Brown, Christopher A.

    or handle prey). Optimal Foraging Theory Developed in late 1960's-early 1970's to address animal decisions is to maximize (or optimize) energy intake Some disagreement over terminology: optimize vs. maximize Forager may1 Foraging Behavior Some Basic Ideas Two individuals involved: predator and prey Predator eats prey

  8. Getting Back to Basics (& Acidics)

    ERIC Educational Resources Information Center

    Rhodes, Sam

    2006-01-01

    This article describes a few novel acid-base experiments intended to introduce students to the basic concepts of acid-base chemistry and provide practical examples that apply directly to the study of biology and the human body. Important concepts such as the reaction between carbon dioxide and water, buffers and protein denaturation, are covered.…

  9. Basic Skills for the Workplace.

    ERIC Educational Resources Information Center

    Taylor, Maurice C., Ed.; And Others

    This book is a practitioner's guide to developing literacy training programs for workers. Titles of the 28 chapters and epilogue are as follows: "Understanding the History and Definitions of Workplace Literacy" (Askov, Aderman); "Understanding Literacy in the Canadian Business Context: Conference Board of Canada Study" (Hart); "Understanding Basic

  10. Information: basic definitions Steven Lindell

    E-print Network

    Lindell, Steven

    10/27/2012 1 Information: basic definitions Steven Lindell Haverford College October 26, 2012 Working Group on Information Fall 2012 Meeting Excerpts from The American Heritage Dictionary · in·for·ma·tion of a specific event or situation; intelligence. 3. A collection of facts or data: statistical information. 4

  11. Starting with the Business Basics.

    ERIC Educational Resources Information Center

    Hoffman, Carl

    1999-01-01

    A nonprofit community action agency, BusinesStart, provides business training and small loans to entrepreneurs in 18 rural counties in southwestern Virginia and northeastern Tennessee. The entrepreneurs, many with no previous business experience, cite the agency's basic business training as key to their success. (SV)

  12. Basic Scientific Subroutines, Volume II.

    ERIC Educational Resources Information Center

    Ruckdeschel, F. R.

    This book, second in a series dealing with scientific programing in the BASIC language, provides students, engineers, and scientists with a documented library of subroutines for scientific applications. Subjects of the eight chapters include: (1) least-squares approximation of functions and smoothing of data; (2) approximating functions by series…

  13. Basic Mathematics Machine Calculator Course.

    ERIC Educational Resources Information Center

    Windsor Public Schools, CT.

    This series of four text-workbooks was designed for tenth grade mathematics students who have exhibited lack of problem-solving skills. Electric desk calculators are to be used with the text. In the first five chapters of the series, students learn how to use the machine while reviewing basic operations with whole numbers, decimals, fractions, and…

  14. The Audit Committee. Board Basics

    ERIC Educational Resources Information Center

    Ostrom, John S.

    2004-01-01

    The Effective Committees set of booklets comprises publications on the following committees: investment, buildings and grounds, academic affairs, student affairs, finance, development, trustees, audit, compensation, and executive. It is part of the AGB Board Basics Series. This report describes the primary role of an audit committee. The primary…

  15. Disability Etiquette Guide The Basics

    E-print Network

    Sibille, Etienne

    The handicapped or the disabled People with disabilities The mentally retarded or he's retarded PeopleDisability Etiquette Guide The Basics ASK BEFORE YOU HELP Interact with the person as a person first! Just because someone has a disability, don't assume he or she needs help. Offer assistance

  16. Welding. Performance Objectives. Basic Course.

    ERIC Educational Resources Information Center

    Vincent, Kenneth

    Several intermediate performance objectives and corresponding criterion measures are listed for each of eight terminal objectives for a basic welding course. The materials were developed for a 36-week (2 hours daily) course developed to teach the fundamentals of welding shop work, to become familiar with the operation of the welding shop…

  17. JSC interactive basic accounting system

    NASA Technical Reports Server (NTRS)

    Spitzer, J. F.

    1978-01-01

    Design concepts for an interactive basic accounting system (IBAS) are considered in terms of selecting the design option which provides the best response at the lowest cost. Modeling the IBAS workload and applying this workload to a U1108 EXEC 8 based system using both a simulation model and the real system is discussed.

  18. Edema (Swelling) (Beyond the Basics)

    MedlinePLUS

    ... a result of a blood clot in the deep veins of the lower leg (called deep vein thrombosis [DVT]). In this case, the edema ... cause swelling of both legs. (See "Patient information: Deep vein thrombosis (DVT) (Beyond the Basics)" .) Pregnancy — Pregnant ...

  19. Cabinetmaking. Performance Objectives. Basic Course.

    ERIC Educational Resources Information Center

    Harvey, Bill

    Several intermediate performance objectives and corresponding criterion measures are listed for each of 15 terminal objectives for a high school basic cabinetmaking course. The materials were developed for a two-semester (2 hours daily) course designed to develop and implement a well-grounded knowledge of the fundamentals of all phases of planning…

  20. Coronary Artery Disease Associated Transcription Factor TCF21 Regulates Smooth Muscle Precursor Cells That Contribute to the Fibrous Cap

    PubMed Central

    Raiesdana, Azad; Kundu, Ramendra; Miller, Clint L.; Kim, Juyong B.; Arora, Komal; Carcamo-Oribe, Ivan; Xiong, Yiqin; Tellakula, Nikhil; Nanda, Vivek; Murthy, Nikitha; Boisvert, William A.; Hedin, Ulf; Perisic, Ljubica; Aldi, Silvia; Maegdefessel, Lars; Pjanic, Milos; Owens, Gary K.; Tallquist, Michelle D.; Quertermous, Thomas

    2015-01-01

    Recent genome wide association studies have identified a number of genes that contribute to the risk for coronary heart disease. One such gene, TCF21, encodes a basic-helix-loop-helix transcription factor believed to serve a critical role in the development of epicardial progenitor cells that give rise to coronary artery smooth muscle cells (SMC) and cardiac fibroblasts. Using reporter gene and immunolocalization studies with mouse and human tissues we have found that vascular TCF21 expression in the adult is restricted primarily to adventitial cells associated with coronary arteries and also medial SMC in the proximal aorta of mouse. Genome wide RNA-Seq studies in human coronary artery SMC (HCASMC) with siRNA knockdown found a number of putative TCF21 downstream pathways identified by enrichment of terms related to CAD, including “vascular disease,” “disorder of artery,” and “occlusion of artery,” as well as disease-related cellular functions including “cellular movement” and “cellular growth and proliferation.” In vitro studies in HCASMC demonstrated that TCF21 expression promotes proliferation and migration and inhibits SMC lineage marker expression. Detailed in situ expression studies with reporter gene and lineage tracing revealed that vascular wall cells expressing Tcf21 before disease initiation migrate into vascular lesions of ApoE-/- and Ldlr-/- mice. While Tcf21 lineage traced cells are distributed throughout the early lesions, in mature lesions they contribute to the formation of a subcapsular layer of cells, and others become associated with the fibrous cap. The lineage traced fibrous cap cells activate expression of SMC markers and growth factor receptor genes. Taken together, these data suggest that TCF21 may have a role regulating the differentiation state of SMC precursor cells that migrate into vascular lesions and contribute to the fibrous cap and more broadly, in view of the association of this gene with human CAD, provide evidence that these processes may be a mechanism for CAD risk attributable to the vascular wall. PMID:26020946

  1. Synergistic nuclear import of NeuroD1 and its partner transcription factor, E47, via heterodimerization

    SciTech Connect

    Mehmood, Rashid; Yasuhara, Noriko; Oe, Souichi; Nagai, Masahiro; Yoneda, Yoshihiro; Department of Biochemistry, Graduate School of Medicine, Osaka University, 2-2 Yamada-oka, Suita, Osaka 565-0871

    2009-06-10

    The transition from undifferentiated pluripotent cells to terminally differentiated neurons is coordinated by a repertoire of transcription factors. NeuroD1 is a type II basic helix loop helix (bHLH) transcription factor that plays critical roles in neuronal differentiation and maintenance in the central nervous system. Its dimerization with E47, a type I bHLH transcription factor, leads to the transcriptional regulation of target genes. Mounting evidence suggests that regulating the localization of transcription factors contributes to the regulation of their activity during development as defects in their localization underlie a variety of developmental disorders. In this study, we attempted to understand the nuclear import mannerisms of NeuroD1 and E47. We found that the nuclear import of NeuroD1 and E47 is energy-dependent and involves the Ran-mediated pathway. Herein, we demonstrate that NeuroD1 and E47 can dimerize inside the cytoplasm before their nuclear import. Moreover, this dimerization promotes nuclear import as the nuclear accumulation of NeuroD1 was enhanced in the presence of E47 in an in vitro nuclear import assay, and NLS-deficient NeuroD1 was successfully imported into the nucleus upon E47 overexpression. NeuroD1 also had a similar effect on the nuclear accumulation of NLS-deficient E47. These findings suggest a novel role for dimerization that may promote, at least partially, the nuclear import of transcription factors allowing them to function efficiently in the nucleus.

  2. A Large Insertion in bHLH Transcription Factor BrTT8 Resulting in Yellow Seed Coat in Brassica rapa

    PubMed Central

    Li, Xia; Chen, Li; Hong, Meiyan; Zhang, Yan; Zu, Feng; Wen, Jing; Yi, Bin; Ma, Chaozhi; Shen, Jinxiong; Tu, Jinxing; Fu, Tingdong

    2012-01-01

    Yellow seed is a desirable quality trait of the Brassica oilseed species. Previously, several seed coat color genes have been mapped in the Brassica species, but the molecular mechanism is still unknown. In the present investigation, map-based cloning method was used to identify a seed coat color gene, located on A9 in B. rapa. Blast analysis with the Arabidopsis genome showed that there were 22 Arabidopsis genes in this region including at4g09820 to at4g10620. Functional complementation test exhibited a phenotype reversion in the Arabidopsis thaliana tt8-1 mutant and yellow-seeded plant. These results suggested that the candidate gene was a homolog of TRANSPARENT TESTA8 (TT8) locus. BrTT8 regulated the accumulation of proanthocyanidins (PAs) in the seed coat. Sequence analysis of two alleles revealed a large insertion of a new class of transposable elements, Helitron in yellow sarson. In addition, no mRNA expression of BrTT8 was detected in the yellow-seeded line. It indicated that the natural transposon might have caused the loss in function of BrTT8. BrTT8 encodes a basic/helix-loop-helix (bHLH) protein that shares a high degree of similarity with other bHLH proteins in the Brassica. Further expression analysis also revealed that BrTT8 was involved in controlling the late biosynthetic genes (LBGs) of the flavonoid pathway. Our present findings provided with further studies could assist in understanding the molecular mechanism involved in seed coat color formation in Brassica species, which is an important oil yielding quality trait. PMID:22984469

  3. Activation of Six1 Expression in Vertebrate Sensory Neurons

    PubMed Central

    Sato, Shigeru; Yajima, Hiroshi; Furuta, Yasuhide; Ikeda, Keiko; Kawakami, Kiyoshi

    2015-01-01

    SIX1 homeodomain protein is one of the essential key regulators of sensory organ development. Six1-deficient mice lack the olfactory epithelium, vomeronasal organs, cochlea, vestibule and vestibuloacoustic ganglion, and also show poor neural differentiation in the distal part of the cranial ganglia. Simultaneous loss of both Six1 and Six4 leads to additional abnormalities such as small trigeminal ganglion and abnormal dorsal root ganglia (DRG). The aim of this study was to understand the molecular mechanism that controls Six1 expression in sensory organs, particularly in the trigeminal ganglion and DRG. To this end, we focused on the sensory ganglia-specific Six1 enhancer (Six1-8) conserved between chick and mouse. In vivo reporter assays using both animals identified an important core region comprising binding consensus sequences for several transcription factors including nuclear hormone receptors, TCF/LEF, SMAD, POU homeodomain and basic-helix-loop-helix proteins. The results provided information on upstream factors and signals potentially relevant to Six1 regulation in sensory neurons. We also report the establishment of a new transgenic mouse line (mSix1-8-NLSCre) that expresses Cre recombinase under the control of mouse Six1-8. Cre-mediated recombination was detected specifically in ISL1/2-positive sensory neurons of Six1-positive cranial sensory ganglia and DRG. The unique features of the mSix1-8-NLSCre line are the absence of Cre-mediated recombination in SOX10-positive glial cells and central nervous system and ability to induce recombination in a subset of neurons derived from the olfactory placode/epithelium. This mouse model can be potentially used to advance research on sensory development. PMID:26313368

  4. Introducing Pitt-Hopkins syndrome-associated mutations of TCF4 to Drosophila daughterless.

    PubMed

    Tamberg, Laura; Sepp, Mari; Timmusk, Tõnis; Palgi, Mari

    2015-01-01

    Pitt-Hopkins syndrome (PTHS) is caused by haploinsufficiency of Transcription factor 4 (TCF4), one of the three human class I basic helix-loop-helix transcription factors called E-proteins. Drosophila has a single E-protein, Daughterless (Da), homologous to all three mammalian counterparts. Here we show that human TCF4 can rescue Da deficiency during fruit fly nervous system development. Overexpression of Da or TCF4 specifically in adult flies significantly decreases their survival rates, indicating that these factors are crucial even after development has been completed. We generated da transgenic fruit fly strains with corresponding missense mutations R578H, R580W, R582P and A614V found in TCF4 of PTHS patients and studied the impact of these mutations in vivo. Overexpression of wild type Da as well as human TCF4 in progenitor tissues induced ectopic sensory bristles and the rough eye phenotype. By contrast, overexpression of Da(R580W) and Da(R582P) that disrupt DNA binding reduced the number of bristles and induced the rough eye phenotype with partial lack of pigmentation, indicating that these act dominant negatively. Compared to the wild type, Da(R578H) and Da(A614V) were less potent in induction of ectopic bristles and the rough eye phenotype, respectively, suggesting that these are hypomorphic. All studied PTHS-associated mutations that we introduced into Da led to similar effects in vivo as the same mutations in TCF4 in vitro. Consequently, our Drosophila models of PTHS are applicable for further studies aiming to unravel the molecular mechanisms of this disorder. PMID:26621827

  5. The N-Myc oncoprotein is associated in vivo with the phosphoprotein Max(p20/22) in human neuroblastoma cells.

    PubMed Central

    Wenzel, A; Cziepluch, C; Hamann, U; Schürmann, J; Schwab, M

    1991-01-01

    Proteins encoded by the proto-oncogenes c-myc, L-myc, and N-myc contain at their carboxy-terminus a tripartite segment comprising a basic DNA binding region (BR), a helix-loop-helix (HLH) and a leucine zipper motif (Zip), that are believed to be involved in DNA binding and protein-protein interaction. The N-Myc oncoprotein is overexpressed in certain human tumors that share neuroectodermal features due to amplification of the N-myc gene. Using a monoclonal antibody directed against an N-terminal epitope of the N-Myc protein in immunoprecipitations performed with extracts of neuroblastoma cells, two nuclear phosphoprotein, p20/22, forming a hetero-oligomeric complex with N-Myc are identified. Both proteins are phosphorylated by casein kinase II in vitro. By partial proteolytic maps we show that p20 and p22 are structurally related to each other and that p20 is identical with Max, a recently described in vitro binding partner of myc proteins. Time course experiments show the presence of the complex in cellular extracts immunoprecipitated within a 5 min interval after the preparation of the cell extract. While the expression of N-myc is restricted, expression of both Max(p20/22) and the murine homolog Myn(p20/22) was observed in cells of diverse human and murine embryonal lineages as detected by heterologous complex formation. By introduction of expression vectors containing the wild type N-myc gene or N-myc genes with in frame deletions or point mutations into recipient cells and subsequent immunoprecipitation of the resulting N-Myc proteins we show that the HLH-Zip region is essential to the formation of the N-Myc-p20/22 complex. Images PMID:1935896

  6. Spermatogonial SOHLH1 nucleocytoplasmic shuttling associates with initiation of spermatogenesis in the rhesus monkey (Macaca mulatta).

    PubMed

    Ramaswamy, Suresh; Razack, Bibi S; Roslund, Rachel M; Suzuki, Hitomi; Marshall, Gary R; Rajkovic, Aleksandar; Plant, Tony M

    2014-04-01

    As the spermatogenesis- and oogenesis-specific basic helix-loop-helix 1 (SOHLH1) transcription factor has been shown to be essential for spermatogonial differentiation in mice, we examined the immunoexpression of this protein in the testis of the rhesus monkey (Macaca mulatta) during puberty, the stage of development when spermatogonial differentiation is initiated in higher primates. Immunopositive SOHLH1 cells were observed only on the basement membrane of the seminiferous cords and tubules. Prior to puberty, essentially 100% of SOHLH1-positive spermatogonia co-expressed the glial cell line-derived neurotrophic factor family receptor alpha 1 (GFR?1), a marker for undifferentiated spermatogonia, and >80% of the immunopositive SOHLH1 cells exhibited only cytoplasmic staining of this transcription factor. Nuclear-only SOHLH1 was found in <10% of spermatogonia in testes from pre-pubertal animals. Puberty was associated with a dramatic and progressive increase in the percentage of immunopositive SOHLH1 cells with nuclear-only staining, and this was associated with (i) a marked reduction in the fraction (?100-20%) of SOHLH1-positive germ cells co-expressing GFR?1 and (ii) a significant increase in the proportion of SOHLH1-positive spermatogonia that co-expressed the tyrosine kinase receptor (cKIT). Spermatogonia exhibiting nuclear SOHLH1 staining were found to be cKIT positive, but not all cKIT-positive spermatogonia exhibited nuclear SOHLH1 staining. Taken together, these results suggest that, in the monkey, nuclear location of SOHLH1 is closely associated with spermatogonial differentiation. PMID:24324034

  7. Spermatogonial SOHLH1 nucleocytoplasmic shuttling associates with initiation of spermatogenesis in the rhesus monkey (Macaca mulatta)

    PubMed Central

    Ramaswamy, Suresh; Razack, Bibi S.; Roslund, Rachel M.; Suzuki, Hitomi; Marshall, Gary R.; Rajkovic, Aleksandar; Plant, Tony M.

    2014-01-01

    As the spermatogenesis- and oogenesis-specific basic helix-loop-helix 1 (SOHLH1) transcription factor has been shown to be essential for spermatogonial differentiation in mice, we examined the immunoexpression of this protein in the testis of the rhesus monkey (Macaca mulatta) during puberty, the stage of development when spermatogonial differentiation is initiated in higher primates. Immunopositive SOHLH1 cells were observed only on the basement membrane of the seminiferous cords and tubules. Prior to puberty, essentially 100% of SOHLH1-positive spermatogonia co-expressed the glial cell line-derived neurotrophic factor family receptor alpha 1 (GFR?1), a marker for undifferentiated spermatogonia, and >80% of the immunopositive SOHLH1 cells exhibited only cytoplasmic staining of this transcription factor. Nuclear-only SOHLH1 was found in <10% of spermatogonia in testes from pre-pubertal animals. Puberty was associated with a dramatic and progressive increase in the percentage of immunopositive SOHLH1 cells with nuclear-only staining, and this was associated with (i) a marked reduction in the fraction (?100–20%) of SOHLH1-positive germ cells co-expressing GFR?1 and (ii) a significant increase in the proportion of SOHLH1-positive spermatogonia that co-expressed the tyrosine kinase receptor (cKIT). Spermatogonia exhibiting nuclear SOHLH1 staining were found to be cKIT positive, but not all cKIT-positive spermatogonia exhibited nuclear SOHLH1 staining. Taken together, these results suggest that, in the monkey, nuclear location of SOHLH1 is closely associated with spermatogonial differentiation. PMID:24324034

  8. Transforming growth factor beta 1-responsive element: closely associated binding sites for USF and CCAAT-binding transcription factor-nuclear factor I in the type 1 plasminogen activator inhibitor gene.

    PubMed Central

    Riccio, A; Pedone, P V; Lund, L R; Olesen, T; Olsen, H S; Andreasen, P A

    1992-01-01

    Transforming growth factor beta (TGF-beta) is the name of a group of closely related polypeptides characterized by a multiplicity of effects, including regulation of extracellular proteolysis and turnover of the extracellular matrix. Its cellular mechanism of action is largely unknown. TGF-beta 1 is a strong and fast inducer of type 1 plasminogen activator inhibitor gene transcription. We have identified a TGF-beta 1-responsive element in the 5'-flanking region of the human type 1 plasminogen activator inhibitor gene and shown that it is functional both in its natural context and when fused to a heterologous nonresponsive promoter. Footprinting and gel retardation experiments showed that two different nuclear factors, present in extracts from both TGF-beta 1-treated and nontreated cells, bind to adjacent sequences contained in the responsive unit. A palindromic sequence binds a trans-acting factor(s) of the CCAAT-binding transcription factor-nuclear factor I family. A partially overlapping dyad symmetry interacts with a second protein that much evidence indicates to be USF. USF is a transactivator belonging to the basic helix-loop-helix family of transcription factors. Mutations which abolish the binding of either CCAAT-binding transcription factor-nuclear factor I or USF result in reduction of transcriptional activation upon exposure to TGF-beta 1, thus showing that both elements of the unit are necessary for the TGF-beta 1 response. We discuss the possible relationship of these findings to the complexity of the TGF-beta action. Images PMID:1549130

  9. Differential modulation of BMP signaling promotes the elaboration of cerebral cortical GABAergic neurons or oligodendrocytes from a common sonic hedgehog-responsive ventral forebrain progenitor species

    PubMed Central

    Yung, Shau-Yu; Gokhan, Solen; Jurcsak, Jennifer; Molero, Aldrin E.; Abrajano, Joseph J.; Mehler, Mark F.

    2002-01-01

    During cerebral cortical development, excitatory glutamatergic projection neurons are generated from neural stem cells intrinsic to the early embryonic cortical ventricular zone by a process of radial migration, whereas most inhibitory ?-aminobutyric acid (GABA)ergic interneurons and oligodendrocytes (OLs) appear to be elaborated from ventral forebrain stem cells that initially undergo tangential cortical migration before terminal lineage maturation. In contrast to the more compartmentalized developmental organization of the spinal cord, the generation of neurons and OLs from a common ventral forebrain stem cell would expose these cells to the sequential actions of ventral and dorsal gradient morphogens [sonic hedgehog (Shh) and bone morphogenetic proteins (BMPs)] that normally mediate opposing developmental programs. Here we report that Shh promotes GABAergic neuronal/OL lineage restriction of forebrain stem cells, in part, by activation of the basic helix–loop–helix transcription factors, Olig2 and Mash1. In mutant mice with a generalized defect in tangential cortical migration (Dlx1/2?/?), there is a profound and selective reduction in the elaboration of both cortical GABAergic neurons and OLs. Our studies further demonstrate that the sequential elaboration of cortical GABAergic neurons and OLs from common Shh-responsive ventral forebrain progenitors requires the spatial and temporal modulation of cortical BMP signaling by BMP ligands and the BMP antagonist, noggin, respectively. These findings suggest an integrative model for cerebral cortical GABAergic neuronal and OL lineage maturation that would incorporate the sequential contributions of the ventral and dorsal forebrain, and the potential role of regional developmental cues in modulating transcriptional codes within evolving neural lineage species. PMID:12461181

  10. Differential modulation of BMP signaling promotes the elaboration of cerebral cortical GABAergic neurons or oligodendrocytes from a common sonic hedgehog-responsive ventral forebrain progenitor species.

    PubMed

    Yung, Shau-Yu; Gokhan, Solen; Jurcsak, Jennifer; Molero, Aldrin E; Abrajano, Joseph J; Mehler, Mark F

    2002-12-10

    During cerebral cortical development, excitatory glutamatergic projection neurons are generated from neural stem cells intrinsic to the early embryonic cortical ventricular zone by a process of radial migration, whereas most inhibitory gamma-aminobutyric acid (GABA)ergic interneurons and oligodendrocytes (OLs) appear to be elaborated from ventral forebrain stem cells that initially undergo tangential cortical migration before terminal lineage maturation. In contrast to the more compartmentalized developmental organization of the spinal cord, the generation of neurons and OLs from a common ventral forebrain stem cell would expose these cells to the sequential actions of ventral and dorsal gradient morphogens [sonic hedgehog (Shh) and bone morphogenetic proteins (BMPs)] that normally mediate opposing developmental programs. Here we report that Shh promotes GABAergic neuronalOL lineage restriction of forebrain stem cells, in part, by activation of the basic helix-loop-helix transcription factors, Olig2 and Mash1. In mutant mice with a generalized defect in tangential cortical migration (Dlx12--), there is a profound and selective reduction in the elaboration of both cortical GABAergic neurons and OLs. Our studies further demonstrate that the sequential elaboration of cortical GABAergic neurons and OLs from common Shh-responsive ventral forebrain progenitors requires the spatial and temporal modulation of cortical BMP signaling by BMP ligands and the BMP antagonist, noggin, respectively. These findings suggest an integrative model for cerebral cortical GABAergic neuronal and OL lineage maturation that would incorporate the sequential contributions of the ventral and dorsal forebrain, and the potential role of regional developmental cues in modulating transcriptional codes within evolving neural lineage species. PMID:12461181

  11. Regulation of BDNF chromatin status and promoter accessibility in a neural correlate of associative learning.

    PubMed

    Ambigapathy, Ganesh; Zheng, Zhaoqing; Keifer, Joyce

    2015-10-01

    Brain-derived neurotrophic factor (BDNF) gene expression critically controls learning and its aberrant regulation is implicated in Alzheimer's disease and a host of neurodevelopmental disorders. The BDNF gene is target of known DNA regulatory mechanisms but details of its activity-dependent regulation are not fully characterized. We performed a comprehensive analysis of the epigenetic regulation of the turtle BDNF gene (tBDNF) during a neural correlate of associative learning using an in vitro model of eye blink classical conditioning. Shortly after conditioning onset, the results from ChIP-qPCR show conditioning-dependent increases in methyl-CpG-binding protein 2 (MeCP2) and repressor basic helix-loop-helix binding protein 2 (BHLHB2) binding to tBDNF promoter II that corresponds with transcriptional repression. In contrast, enhanced binding of ten-eleven translocation protein 1 (Tet1), extracellular signal-regulated kinase 1/2 (ERK1/2), and cAMP response element-binding protein (CREB) to promoter III corresponds with transcriptional activation. These actions are accompanied by rapid modifications in histone methylation and phosphorylation status of RNA polymerase II (RNAP II). Significantly, these remarkably coordinated changes in epigenetic factors for two alternatively regulated tBDNF promoters during conditioning are controlled by Tet1 and ERK1/2. Our findings indicate that Tet1 and ERK1/2 are critical partners that, through complementary functions, control learning-dependent tBDNF promoter accessibility required for rapid transcription and acquisition of classical conditioning. PMID:26336984

  12. ChIP-seq and In Vivo Transcriptome Analyses of the Aspergillus fumigatus SREBP SrbA Reveals a New Regulator of the Fungal Hypoxia Response and Virulence

    PubMed Central

    Merriman, Brittney; Werner, Ernst R.; Lechner, Beatrix E.; Dhingra, Sourabh; Cheng, Chao; Xu, Wenjie; Blosser, Sara J.; Morohashi, Kengo; Mazurie, Aurélien; Mitchell, Thomas K.; Haas, Hubertus; Mitchell, Aaron P.; Cramer, Robert A.

    2014-01-01

    The Aspergillus fumigatus sterol regulatory element binding protein (SREBP) SrbA belongs to the basic Helix-Loop-Helix (bHLH) family of transcription factors and is crucial for antifungal drug resistance and virulence. The latter phenotype is especially striking, as loss of SrbA results in complete loss of virulence in murine models of invasive pulmonary aspergillosis (IPA). How fungal SREBPs mediate fungal virulence is unknown, though it has been suggested that lack of growth in hypoxic conditions accounts for the attenuated virulence. To further understand the role of SrbA in fungal infection site pathobiology, chromatin immunoprecipitation followed by massively parallel DNA sequencing (ChIP-seq) was used to identify genes under direct SrbA transcriptional regulation in hypoxia. These results confirmed the direct regulation of ergosterol biosynthesis and iron uptake by SrbA in hypoxia and revealed new roles for SrbA in nitrate assimilation and heme biosynthesis. Moreover, functional characterization of an SrbA target gene with sequence similarity to SrbA identified a new transcriptional regulator of the fungal hypoxia response and virulence, SrbB. SrbB co-regulates genes involved in heme biosynthesis and demethylation of C4-sterols with SrbA in hypoxic conditions. However, SrbB also has regulatory functions independent of SrbA including regulation of carbohydrate metabolism. Loss of SrbB markedly attenuates A. fumigatus virulence, and loss of both SREBPs further reduces in vivo fungal growth. These data suggest that both A. fumigatus SREBPs are critical for hypoxia adaptation and virulence and reveal new insights into SREBPs' complex role in infection site adaptation and fungal virulence. PMID:25375670

  13. ATOH7 mutations cause autosomal recessive persistent hyperplasia of the primary vitreous

    PubMed Central

    Prasov, Lev; Masud, Tehmina; Khaliq, Shagufta; Mehdi, S. Qasim; Abid, Aiysha; Oliver, Edward R.; Silva, Eduardo D.; Lewanda, Amy; Brodsky, Michael C.; Borchert, Mark; Kelberman, Daniel; Sowden, Jane C.; Dattani, Mehul T.; Glaser, Tom

    2012-01-01

    The vertebrate basic helix–loop–helix (bHLH) transcription factor ATOH7 (Math5) is specifically expressed in the embryonic neural retina and is required for the genesis of retinal ganglion cells (RGCs) and optic nerves. In Atoh7 mutant mice, the absence of trophic factors secreted by RGCs prevents the development of the intrinsic retinal vasculature and the regression of fetal blood vessels, causing persistent hyperplasia of the primary vitreous (PHPV). We therefore screened patients with hereditary PHPV, as well as bilateral optic nerve aplasia (ONA) or hypoplasia (ONH), for mutations in ATOH7. We identified a homozygous ATOH7 mutation (N46H) in a large family with an autosomal recessive PHPV disease trait linked to 10q21, and a heterozygous variant (R65G, p.Arg65Gly) in one of five sporadic ONA patients. High-density single-nucleotide polymorphism analysis also revealed a CNTN4 duplication and an OTX2 deletion in the ONA cohort. Functional analysis of ATOH7 bHLH domain substitutions, by electrophoretic mobility shift and luciferase cotransfection assays, revealed that the N46H variant cannot bind DNA or activate transcription, consistent with structural modeling. The N46H variant also failed to rescue RGC development in mouse Atoh7?/? retinal explants. The R65G variant retains all of these activities, similar to wild-type human ATOH7. Our results strongly suggest that autosomal recessive persistent hyperplastic primary vitreous is caused by N46H and is etiologically related to nonsyndromic congenital retinal nonattachment. The R65G allele, however, cannot explain the ONA phenotype. Our study firmly establishes ATOH7 as a retinal disease gene and provides a functional basis to analyze new coding variants. PMID:22645276

  14. E-box- and MEF-2-independent muscle-specific expression, positive autoregulation, and cross-activation of the chicken MyoD (CMD1) promoter reveal an indirect regulatory pathway.

    PubMed Central

    Dechesne, C A; Wei, Q; Eldridge, J; Gannoun-Zaki, L; Millasseau, P; Bougueleret, L; Caterina, D; Paterson, B M

    1994-01-01

    Members of the MyoD family of gene-regulatory proteins (MyoD, myogenin, myf5, and MRF4) have all been shown not only to regulate the transcription of numerous muscle-specific genes but also to positively autoregulate and cross activate each other's transcription. In the case of muscle-specific genes, this transcriptional regulation can often be correlated with the presence of a DNA consensus in the regulatory region CANNTG, known as an E box. Little is known about the regulatory interactions of the myogenic factors themselves; however, these interactions are thought to be important for the activation and maintenance of the muscle phenotype. We have identified the minimal region in the chicken MyoD (CMD1) promoter necessary for muscle-specific transcription in primary cultures of embryonic chicken skeletal muscle. The CMD1 promoter is silent in primary chick fibroblast cultures and in muscle cell cultures treated with the thymidine analog bromodeoxyuridine. However, CMD1 and chicken myogenin, as well as, to a lesser degree, chicken Myf5 and MRF4, expressed in trans can activate transcription from the minimal CMD1 promoter in these primary fibroblast cultures. Here we show that the CMD1 promoter contains numerous E-box binding sites for CMD1 and the other myogenic factors, as well as a MEF-2 binding site. Surprisingly, neither muscle-specific and the other myogenic factors, as well as a MEF-2 binding site. Surprisingly, neither muscle-specific expression, autoregulation, or cross activation depends upon the presence of of these E-box or MEF-2 binding sites in the CMD1 promoter. These results demonstrate that the autoregulation and cross activation of the chicken MyoD promoter through the putative direct binding of the myogenic basic helix-loop-helix regulatory factors is mediated through an indirect pathway that involves unidentified regulatory elements and/or ancillary factors. Images PMID:8035824

  15. TCF4 Triplet Repeat Expansion and Nuclear RNA Foci in Fuchs' Endothelial Corneal Dystrophy

    PubMed Central

    Mootha, V. Vinod; Hussain, Imran; Cunnusamy, Khrishen; Graham, Eric; Gong, Xin; Neelam, Sudha; Xing, Chao; Kittler, Ralf; Petroll, W. Matthew

    2015-01-01

    Purpose. Expansion of the intronic CTG18.1 triplet repeat locus within TCF4 contributes significant risk to the development of Fuchs' endothelial corneal dystrophy (FECD) in Eurasian populations, but the mechanisms by which the expanded repeats result in degeneration of the endothelium have been hitherto unknown. The purpose of this study was to examine FECD endothelial samples for the presence of RNA nuclear foci, the hallmark of toxic RNA, as well as evidence of haploinsufficiency of TCF4. Methods. Using fluorescence in situ hybridization, we examined for the presence of nuclear RNA foci containing expanded CUG transcripts in corneal endothelial samples from FECD subjects with CTG18.1 expansion. We also examined for any changes in expression levels of TCF4 by quantitative real-time PCR. Results. Numerous discrete nuclear RNA foci were identified in endothelial samples of FECD subjects (n = 8) harboring the CTG18.1 expansion, but not in controls lacking the expansion (n = 5) (P = 7.8 × 10?4). Percentage of cells with foci in expansion-positive endothelial samples ranged from 33% to 88%. RNA foci were absent in endothelial samples from an FECD subject without CTG18.1 expansion and a subject with endothelial dysfunction without FECD. Expression of the constitutive TCF4 exon encoding the basic helix-loop-helix domain was unaltered with CTG18.1 expansion. Conclusions. Our findings suggest that the RNA nuclear foci are pathognomonic for CTG18.1 expansion-mediated endothelial disease. The RNA nuclear foci have been previously found only in rare neurodegenerative disorders caused by repeat expansions. Our detection of abundant ribonuclear foci in FECD implicates a role for toxic RNA in this common disease. PMID:25722209

  16. Shutdown of Achaete-scute Homolog-1 Expression by Heterogeneous Nuclear Ribonucleoprotein (hnRNP)-A2/B1 in Hypoxia*

    PubMed Central

    Kasim, Mumtaz; Benko, Edgar; Winkelmann, Aline; Mrowka, Ralf; Staudacher, Jonas J.; Persson, Pontus B.; Scholz, Holger; Meier, Jochen C.; Fähling, Michael

    2014-01-01

    The basic helix-loop-helix transcription factor hASH1, encoded by the ASCL1 gene, plays an important role in neurogenesis and tumor development. Recent findings indicate that local oxygen tension is a critical determinant for the progression of neuroblastomas. Here we investigated the molecular mechanisms underlying the oxygen-dependent expression of hASH1 in neuroblastoma cells. Exposure of human neuroblastoma-derived Kelly cells to 1% O2 significantly decreased ASCL1 mRNA and hASH1 protein levels. Using reporter gene assays, we show that the response of hASH1 to hypoxia is mediated mainly by post-transcriptional inhibition via the ASCL1 mRNA 5?- and 3?-UTRs, whereas additional inhibition of the ASCL1 promoter was observed under prolonged hypoxia. By RNA pulldown experiments followed by MALDI/TOF-MS analysis, we identified heterogeneous nuclear ribonucleoprotein (hnRNP)-A2/B1 and hnRNP-R as interactors binding directly to the ASCL1 mRNA 5?- and 3?-UTRs and influencing its expression. We further demonstrate that hnRNP-A2/B1 is a key positive regulator of ASCL1, findings that were also confirmed by analysis of a large compilation of gene expression data. Our data suggest that a prominent down-regulation of hnRNP-A2/B1 during hypoxia is associated with the post-transcriptional suppression of hASH1 synthesis. This novel post-transcriptional mechanism for regulating hASH1 levels will have important implications in neural cell fate development and disease. PMID:25124043

  17. Far-Red Light-Mediated Seedling Development in Arabidopsis Involves FAR-RED INSENSITIVE 219/JASMONATE RESISTANT 1-Dependent and -Independent Pathways

    PubMed Central

    Chen, Huai-Ju; Chen, Cheng-Ling; Hsieh, Hsu-Liang

    2015-01-01

    Plant growth and development is often regulated by the interaction of environmental factors such as light and various phytohormones. Arabidopsis FAR-RED INSENSITIVE 219 (FIN219)/JASMONATE RESISTANT 1 (JAR1) participates in phytochrome A-mediated far-red (FR) light signaling and interacts with different light signaling regulators. FIN219/JAR1 is a jasmonic acid (JA)-conjugating enzyme responsible for the formation of JA-isoleucine. However, how FIN219/JAR1 integrates FR light and JA signaling remains largely unknown. We used a microarray approach to dissect the effect of fin219 mutation on the interaction of FR light and JA signaling. The fin219-2 mutant was less sensitive than the wild type to various concentrations of methyl jasmonate (MeJA) under low and high FR light. High FR light reduced the sensitivity of Arabidopsis seedlings to MeJA likely through FIN219. Intriguingly, in response to MeJA, FIN219 levels showed a negative feedback regulation. Further microarray assay revealed that FR light could regulate gene expression by FIN219-dependent or -independent pathways. The expression profiles affected in fin219-2 indicated that FIN219/JAR1 plays a critical role in the integration of multiple hormone-related signaling. In particular, FIN219 regulates a number of transcription factors (TFs), including 94 basic helix-loop-helix (bHLH) TFs, in response to FR light and MeJA. Loss-of-function mutants of some bHLH TFs affected by FIN219 showed altered responses to MeJA in the regulation of hypocotyl and root elongation. Thus, FIN219/JAR1 is tightly regulated in response to exogenous MeJA. It also interacts with multiple plant hormones to modulate hypocotyl and root elongation of Arabidopsis seedlings likely by regulating a group of TFs. PMID:26176841

  18. The role of dimerisation and nuclear transport in the Hes1 gene regulatory network.

    PubMed

    Sturrock, Marc; Hellander, Andreas; Aldakheel, Sahar; Petzold, Linda; Chaplain, Mark A J

    2014-04-01

    Hes1 is a member of the family of basic helix-loop-helix transcription factors and the Hes1 gene regulatory network (GRN) may be described as the canonical example of transcriptional control in eukaryotic cells, since it involves only the Hes1 protein and its own mRNA. Recently, the Hes1 protein has been established as an excellent target for an anti-cancer drug treatment, with the design of a small molecule Hes1 dimerisation inhibitor representing a promising if challenging approach to therapy. In this paper, we extend a previous spatial stochastic model of the Hes1 GRN to include nuclear transport and dimerisation of Hes1 monomers. Initially, we assume that dimerisation occurs only in the cytoplasm, with only dimers being imported into the nucleus. Stochastic simulations of this novel model using the URDME software show that oscillatory dynamics in agreement with experimental studies are retained. Furthermore, we find that our model is robust to changes in the nuclear transport and dimerisation parameters. However, since the precise dynamics of the nuclear import of Hes1 and the localisation of the dimerisation reaction are not known, we consider a second modelling scenario in which we allow for both Hes1 monomers and dimers to be imported into the nucleus, and we allow dimerisation of Hes1 to occur everywhere in the cell. Once again, computational solutions of this second model produce oscillatory dynamics in agreement with experimental studies. We also explore sensitivity of the numerical solutions to nuclear transport and dimerisation parameters. Finally, we compare and contrast the two different modelling scenarios using numerical experiments that simulate dimer disruption, and suggest a biological experiment that could distinguish which model more faithfully captures the Hes1 GRN. PMID:23686434

  19. The bHLH Transcription Factors TSAR1 and TSAR2 Regulate Triterpene Saponin Biosynthesis in Medicago truncatula.

    PubMed

    Mertens, Jan; Pollier, Jacob; Vanden Bossche, Robin; Lopez-Vidriero, Irene; Franco-Zorrilla, José Manuel; Goossens, Alain

    2016-01-01

    Plants respond to stresses by producing a broad spectrum of bioactive specialized metabolites. Hormonal elicitors, such as jasmonates, trigger a complex signaling circuit leading to the concerted activation of specific metabolic pathways. However, for many specialized metabolic pathways, the transcription factors involved remain unknown. Here, we report on two homologous jasmonate-inducible transcription factors of the basic helix-loop-helix family, TRITERPENE SAPONIN BIOSYNTHESIS ACTIVATING REGULATOR1 (TSAR1) and TSAR2, which direct triterpene saponin biosynthesis in Medicago truncatula. TSAR1 and TSAR2 are coregulated with and transactivate the genes encoding 3-HYDROXY-3-METHYLGLUTARYL-COENZYME A REDUCTASE1 (HMGR1) and MAKIBISHI1, the rate-limiting enzyme for triterpene biosynthesis and an E3 ubiquitin ligase that controls HMGR1 levels, respectively. Transactivation is mediated by direct binding of TSARs to the N-box in the promoter of HMGR1. In transient expression assays in tobacco (Nicotiana tabacum) protoplasts, TSAR1 and TSAR2 exhibit different patterns of transactivation of downstream triterpene saponin biosynthetic genes, hinting at distinct functionalities within the regulation of the pathway. Correspondingly, overexpression of TSAR1 or TSAR2 in M. truncatula hairy roots resulted in elevated transcript levels of known triterpene saponin biosynthetic genes and strongly increased the accumulation of triterpene saponins. TSAR2 overexpression specifically boosted hemolytic saponin biosynthesis, whereas TSAR1 overexpression primarily stimulated nonhemolytic soyasaponin biosynthesis. Both TSARs also activated all genes of the precursor mevalonate pathway but did not affect sterol biosynthetic genes, pointing to their specific role as regulators of specialized triterpene metabolism in M. truncatula. PMID:26589673

  20. Gene expression profiling of the hyperplastic growth zones of the late trout embryo myotome using laser capture microdissection and microarray analysis

    PubMed Central

    2013-01-01

    Background A unique feature of fish is that new muscle fibres continue to be produced throughout much of the life cycle; a process termed muscle hyperplasia. In trout, this process begins in the late embryo stage and occurs in both a discrete, continuous layer at the surface of the primary myotome (stratified hyperplasia) and between existing muscle fibres throughout the myotome (mosaic hyperplasia). In post-larval stages, muscle hyperplasia is only of the mosaic type and persists until 40% of the maximum body length is reached. To characterise the genetic basis of myotube neoformation in trout, we combined laser capture microdissection and microarray analysis to compare the transcriptome of hyperplastic regions of the late embryo myotome with that of adult myotomal muscle, which displays only limited hyperplasia. Results Gene expression was analysed using Agilent trout oligo microarrays. Our analysis identified more than 6800 transcripts that were significantly up-regulated in the superficial hyperplastic zones of the late embryonic myotome compared to adult myotomal muscle. In addition to Pax3, Pax7 and the fundamental myogenic basic helix-loop-helix regulators, we identified a large set of up-regulated transcriptional factors, including Myc paralogs, members of Hes family and many homeobox-containing transcriptional regulators. Other cell-autonomous regulators overexpressed in hyperplastic zones included a large set of cell surface proteins belonging to the Ig superfamily. Among the secreted molecules found to be overexpressed in hyperplastic areas, we noted growth factors as well as signalling molecules. A novel finding in our study is that many genes that regulate planar cell polarity (PCP) were overexpressed in superficial hyperplastic zones, suggesting that the PCP pathway is involved in the oriented elongation of the neofibres. Conclusion The results obtained in this study provide a valuable resource for further analysis of novel genes potentially involved in hyperplastic muscle growth in fish. Ultimately, this study could yield insights into particular genes, pathways or cellular processes that may stimulate muscle regeneration in other vertebrates. PMID:23497127

  1. Upstream stimulatory factor (USF) as a transcriptional suppressor of human telomerase reverse transcriptase (hTERT) in oral cancer cells.

    PubMed

    Chang, Joseph Tung-Chieh; Yang, Huei-Ting; Wang, Tzu-Chien V; Cheng, Ann-Joy

    2005-11-01

    Telomerase activity is suppressed in normal human somatic tissues but is activated in cancer cells and immortal cell lines. The reverse transcriptase (RT) subunit human telomerase reverse transcriptase (hTERT) is the key regulator of telomerase activity. The hTERT promoter contains E-box elements and may allow upstream stimulatory factor (USF), a basic helix-loop-helix (bHLH) leucine zipper family proteins, to bind and regulate the expression. In this study, we investigated whether and how USF effect on hTERT. Through luciferase reporter assays, we found that both USF1 and USF2 possess a comparable effect on the inhibition of hTERT expression. Immunoprecipitation (IP) and immunoblotting (IB) analysis reveal that the suppression of hTERT by USF was not through the interaction of USF with c-myc or mad, nor disturbed the cellular protein levels of those. In gel mobility shift and chromatin immunoprecipitation (CHIP) assays, we found that the USF suppression is through direct binding at the E-box site of hTERT promoter and rendering the effect actively. Analysis on clinical normal and tumor tissues reveal that the expression of USF1 and USF2 was lower in the tumor tissues, correlated with hTERT expression and telomerase activity. Taking together, our results demonstrate that USF is a negative transcriptional repressor for hTERT in oral cancer cells. It is possible that USF lose the inhibitory effect on hTERT expression leading to telomerase reactivation and oral carcinogenesis. PMID:16010690

  2. Rox, a novel bHLHZip protein expressed in quiescent cells that heterodimerizes with Max, binds a non-canonical E box and acts as a transcriptional repressor.

    PubMed Central

    Meroni, G; Reymond, A; Alcalay, M; Borsani, G; Tanigami, A; Tonlorenzi, R; Nigro, C L; Messali, S; Zollo, M; Ledbetter, D H; Brent, R; Ballabio, A; Carrozzo, R

    1997-01-01

    Proteins of the Myc and Mad family are involved in transcriptional regulation and mediate cell differentiation and proliferation. These molecules share a basic-helix-loop-helix leucine zipper domain (bHLHZip) and bind DNA at the E box (CANNTG) consensus by forming heterodimers with Max. We report the isolation, characterization and mapping of a human gene and its mouse homolog encoding a new member of this family of proteins, named Rox. Through interaction mating and immunoprecipitation techniques, we demonstrate that Rox heterodimerizes with Max and weakly homodimerizes. Interestingly, bandshift assays demonstrate that the Rox-Max heterodimer shows a novel DNA binding specificity, having a higher affinity for the CACGCG site compared with the canonical E box CACGTG site. Transcriptional studies indicate that Rox represses transcription in both human HEK293 cells and yeast. We demonstrate that repression in yeast is through interaction between the N-terminus of the protein and the Sin3 co-repressor, as previously shown for the other Mad family members. ROX is highly expressed in quiescent fibroblasts and expression markedly decreases when cells enter the cell cycle. Moreover, ROX expression appears to be induced in U937 myeloid leukemia cells stimulated to differentiate with 12-O-tetradecanoylphorbol-13-acetate. The identification of a novel Max-interacting protein adds an important piece to the puzzle of Myc/Max/Mad coordinated action and function in normal and pathological situations. Furthermore, mapping of the human gene to chromosome 17p13.3 in a region that frequently undergoes loss of heterozygosity in a number of malignancies, together with the biochemical and expression features, suggest involvement of ROX in human neoplasia. PMID:9184233

  3. Genetic Analysis of Strawberry Fruit Aroma and Identification of O-Methyltransferase FaOMT as the Locus Controlling Natural Variation in Mesifurane Content1[C][W][OA

    PubMed Central

    Zorrilla-Fontanesi, Yasmín; Rambla, José-Luis; Cabeza, Amalia; Medina, Juan J.; Sánchez-Sevilla, José F.; Valpuesta, Victoriano; Botella, Miguel A.; Granell, Antonio; Amaya, Iraida

    2012-01-01

    Improvement of strawberry (Fragaria × ananassa) fruit flavor is an important goal in breeding programs. To investigate genetic factors controlling this complex trait, a strawberry mapping population derived from genotype ‘1392’, selected for its superior flavor, and ‘232’ was profiled for volatile compounds over 4 years by headspace solid phase microextraction coupled to gas chromatography and mass spectrometry. More than 300 volatile compounds were detected, of which 87 were identified by comparison of mass spectrum and retention time to those of pure standards. Parental line ‘1392’ displayed higher volatile levels than ‘232’, and these and many other compounds with similar levels in both parents segregated in the progeny. Cluster analysis grouped the volatiles into distinct chemically related families and revealed a complex metabolic network underlying volatile production in strawberry fruit. Quantitative trait loci (QTL) detection was carried out over 3 years based on a double pseudo-testcross strategy. Seventy QTLs covering 48 different volatiles were detected, with several of them being stable over time and mapped as major QTLs. Loci controlling ?-decalactone and mesifurane content were mapped as qualitative traits. Using a candidate gene approach we have assigned genes that are likely responsible for several of the QTLs. As a proof of concept we show that one homoeolog of the O-methyltransferase gene (FaOMT) is the locus responsible for the natural variation of mesifurane content. Sequence analysis identified 30 bp in the promoter of this FaOMT homoeolog containing putative binding sites for basic/helix-loop-helix, MYB, and BZIP transcription factors. This polymorphism fully cosegregates with both the presence of mesifurane and the high expression of FaOMT during ripening. PMID:22474217

  4. CpG methylation in exon 1 of transcription factor 4 increases with age in normal gastric mucosa and is associated with gene silencing in intestinal-type gastric cancers

    PubMed Central

    Kim, Seung-Kyoon; Jang, Hay-Ran; Kim, Jeong-Hwan; Kim, Mirang; Noh, Seung-Moo; Song, Kyu-Sang; Kang, Gyeong Hoon; Kim, Hee Jin; Kim, Seon-Young; Yoo, Hyang-Sook; Kim, Yong Sung

    2008-01-01

    Transcriptional factor 4 (TCF4), encoding a basic helix-loop-helix transcriptional factor, has recently been demonstrated as a causative gene for Pitt-Hopkins syndrome, a neurodevelopmental disease. Examination of gastric cancers using the restriction landmark genomic scanning technique revealed methylation at a NotI enzyme site in TCF4 intron 8 and further identified CpG dinucleotide hypermethylation in TCF4 exon 1, strongly associated with gene silencing in gastric cancer cell lines. Treatment with 5-aza-2?-deoxycytidine and/or trichostatin A restored TCF4 expression in TCF4-silenced gastric cancer cell lines. Real-time reverse transcription–polymerase chain reaction analysis of 77 paired primary gastric tumor samples revealed that 38% of analyzed tumors had a >2-fold decrease in TCF4 expression compared with adjacent normal-appearing tissue, and the decrease significantly correlated with increased CpG methylation in TCF4 exon 1. Clinicopathologic data showed that decreased TCF4 expression occurred significantly more frequently in intestinal-type (22/37, 59%) than in diffuse-type (7/37, 19%) gastric cancers (P = 0.0004) and likewise more frequently in early (12/18, 67%) than in advanced (17/59, 29%) gastric cancers (P = 0.004). CpG methylation markedly increased with patient age among normal-appearing tissues, suggesting that CpG methylation in gastric mucosa may be one of the earliest events in carcinogenesis of intestinal-type gastric cancers. Furthermore, ectopic expression of TCF4 decreased cell growth in a gastric cancer cell line, and the knock down of TCF4 using small interfering RNA increased cell migration. Based on these results, we propose that the observed frequent epigenetic-mediated TCF4 silencing plays a role in tumor formation and progression. PMID:18635522

  5. qRT9, a quantitative trait locus controlling root thickness and root length in upland rice.

    PubMed

    Li, Junzhou; Han, Yingchun; Liu, Lei; Chen, Yipeng; Du, Yanxiu; Zhang, Jing; Sun, Hongzheng; Zhao, Quanzhi

    2015-05-01

    Breeding for strong root systems is an important strategy for improving drought avoidance in rice. To clone genes responsible for strong root traits, an upland rice introgression line IL392 with thicker and longer roots than the background parent lowland rice Yuefu was selected. A quantitative trait locus (QTL), qRT9, controlling root thickness and root length was detected under hydroponic culture using 203 F(2:3) populations derived from a cross between Yuefu and IL392. The qRT9 locus explained 32.5% and 28.1% of the variance for root thickness and root length, respectively. Using 3185 F2 plants, qRT9 was ultimately narrowed down to an 11.5 kb region by substitution mapping. One putative basic helix-loop-helix (bHLH) transcription factor gene, LOC_Os09g28210 (named OsbHLH120), is annotated in this region. Sequences of OsbHLH120 in 11 upland rice and 13 lowland rice indicated that a single nucleotide polymorphism (SNP) at position 82 and an insertion/deletion (Indel) at position 628-642 cause amino acid changes and are conserved between upland rice and lowland rice. Phenotypic analysis indicated that the two polymorphisms were significantly associated with root thickness and root length under hydroponic culture. Quantitative real-time PCR showed that OsbHLH120 was strongly induced by polyethylene glycol (PEG), salt, and abscisic acid, but higher expression was present in IL392 roots than in Yuefu under PEG and salt stress. The successfully isolated locus, qRT9, enriches our knowledge of the genetic basis for drought avoidance and provides an opportunity for breeding drought avoidance varieties by utilizing valuable genes in the upland rice germplasm. PMID:25769309

  6. Severe mental retardation with breathing abnormalities (Pitt-Hopkins syndrome) is caused by haploinsufficiency of the neuronal bHLH transcription factor TCF4.

    PubMed

    Brockschmidt, Antje; Todt, Unda; Ryu, Soojin; Hoischen, Alexander; Landwehr, Christina; Birnbaum, Stefanie; Frenck, Wilhelm; Radlwimmer, Bernhard; Lichter, Peter; Engels, Hartmut; Driever, Wolfgang; Kubisch, Christian; Weber, Ruthild G

    2007-06-15

    Pitt-Hopkins syndrome (PHS) is a rare syndromic mental disorder, which is mainly characterized by severe motor and mental retardation including absent language development, a characteristic facial gestalt and episodes of hyperventilation. We report on a female patient with PHS showing severe mental retardation with absent speech, pronounced muscular hypotonia, ataxia, distinctive facial features, such as a coarse face, a broad nasal bridge and a wide mouth, and hyperventilation attacks. In this patient, genomic profiling by array-based comparative genomic hybridization and fluorescence in situ hybridization studies detected and confirmed a de novo 0.5 Mb deletion in 18q21.2 containing a single gene, the basic helix-loop-helix transcription factor TCF4. cDNA and genomic analyses in the patient and her parents demonstrated TCF4 haploinsufficiency as the underlying cause of the disease. Analysis of the embryonal expression pattern of the Danio rerio ortholog, tcf4, by whole-mount in situ hybridization showed a highly specific expression domain in the pallium of the telencephalon during late somitogenesis, when the patterning of the zebrafish brain is advanced and neural differentiation commences. Later expression domains were restricted to several regions in the central nervous system, including continued expression in the pallium of the telencephalon, and starting expression in the diencephalon (thalamus, ventral thalamus and posterior tuberculum), the midbrain tegmentum, the hindbrain and the branchial arches. This expression pattern correlates with the clinical phenotype. Our results show that haploinsufficiency of TCF4 causes PHS and suggest that D. rerio is a valuable model to study the molecular pathogenesis of PHS and the role of TCF4 in brain development. PMID:17478476

  7. Cannabidiol as a novel inhibitor of Id-1 gene expression in aggressive breast cancer cells.

    PubMed

    McAllister, Sean D; Christian, Rigel T; Horowitz, Maxx P; Garcia, Amaia; Desprez, Pierre-Yves

    2007-11-01

    Invasion and metastasis of aggressive breast cancer cells is the final and fatal step during cancer progression, and is the least understood genetically. Clinically, there are still limited therapeutic interventions for aggressive and metastatic breast cancers available. Clearly, effective and nontoxic therapies are urgently required. Id-1, an inhibitor of basic helix-loop-helix transcription factors, has recently been shown to be a key regulator of the metastatic potential of breast and additional cancers. Using a mouse model, we previously determined that metastatic breast cancer cells became significantly less invasive in vitro and less metastatic in vivo when Id-1 was down-regulated by stable transduction with antisense Id-1. It is not possible at this point, however, to use antisense technology to reduce Id-1 expression in patients with metastatic breast cancer. Here, we report that cannabidiol (CBD), a cannabinoid with a low-toxicity profile, could down-regulate Id-1 expression in aggressive human breast cancer cells. The CBD concentrations effective at inhibiting Id-1 expression correlated with those used to inhibit the proliferative and invasive phenotype of breast cancer cells. CBD was able to inhibit Id-1 expression at the mRNA and protein level in a concentration-dependent fashion. These effects seemed to occur as the result of an inhibition of the Id-1 gene at the promoter level. Importantly, CBD did not inhibit invasiveness in cells that ectopically expressed Id-1. In conclusion, CBD represents the first nontoxic exogenous agent that can significantly decrease Id-1 expression in metastatic breast cancer cells leading to the down-regulation of tumor aggressiveness. PMID:18025276

  8. Evolution of the bHLH Genes Involved in Stomatal Development: Implications for the Expansion of Developmental Complexity of Stomata in Land Plants

    PubMed Central

    Ran, Jin-Hua; Shen, Ting-Ting; Liu, Wen-Juan; Wang, Xiao-Quan

    2013-01-01

    Stomata play significant roles in plant evolution. A trio of closely related basic Helix-Loop-Helix (bHLH) subgroup Ia genes, SPCH, MUTE and FAMA, mediate sequential steps of stomatal development, and their functions may be conserved in land plants. However, the evolutionary history of the putative SPCH/MUTE/FAMA genes is still greatly controversial, especially the phylogenetic positions of the bHLH Ia members from basal land plants. To better understand the evolutionary pattern and functional diversity of the bHLH genes involved in stomatal development, we made a comprehensive evolutionary analysis of the homologous genes from 54 species representing the major lineages of green plants. The phylogenetic analysis indicated: (1) All bHLH Ia genes from the two basal land plants Physcomitrella and Selaginella were closely related to the FAMA genes of seed plants; and (2) the gymnosperm ‘SPCH’ genes were sister to a clade comprising the angiosperm SPCH and MUTE genes, while the FAMA genes of gymnosperms and angiosperms had a sister relationship. The revealed phylogenetic relationships are also supported by the distribution of gene structures and previous functional studies. Therefore, we deduce that the function of FAMA might be ancestral in the bHLH Ia subgroup. In addition, the gymnosperm “SPCH” genes may represent an ancestral state and have a dual function of SPCH and MUTE, two genes that could have originated from a duplication event in the common ancestor of angiosperms. Moreover, in angiosperms, SPCHs have experienced more duplications and harbor more copies than MUTEs and FAMAs, which, together with variation of the stomatal development in the entry division, implies that SPCH might have contributed greatly to the diversity of stomatal development. Based on the above, we proposed a model for the correlation between the evolution of stomatal development and the genes involved in this developmental process in land plants. PMID:24244399

  9. Evolution of the bHLH genes involved in stomatal development: implications for the expansion of developmental complexity of stomata in land plants.

    PubMed

    Ran, Jin-Hua; Shen, Ting-Ting; Liu, Wen-Juan; Wang, Xiao-Quan

    2013-01-01

    Stomata play significant roles in plant evolution. A trio of closely related basic Helix-Loop-Helix (bHLH) subgroup Ia genes, SPCH, MUTE and FAMA, mediate sequential steps of stomatal development, and their functions may be conserved in land plants. However, the evolutionary history of the putative SPCH/MUTE/FAMA genes is still greatly controversial, especially the phylogenetic positions of the bHLH Ia members from basal land plants. To better understand the evolutionary pattern and functional diversity of the bHLH genes involved in stomatal development, we made a comprehensive evolutionary analysis of the homologous genes from 54 species representing the major lineages of green plants. The phylogenetic analysis indicated: (1) All bHLH Ia genes from the two basal land plants Physcomitrella and Selaginella were closely related to the FAMA genes of seed plants; and (2) the gymnosperm 'SPCH' genes were sister to a clade comprising the angiosperm SPCH and MUTE genes, while the FAMA genes of gymnosperms and angiosperms had a sister relationship. The revealed phylogenetic relationships are also supported by the distribution of gene structures and previous functional studies. Therefore, we deduce that the function of FAMA might be ancestral in the bHLH Ia subgroup. In addition, the gymnosperm "SPCH" genes may represent an ancestral state and have a dual function of SPCH and MUTE, two genes that could have originated from a duplication event in the common ancestor of angiosperms. Moreover, in angiosperms, SPCHs have experienced more duplications and harbor more copies than MUTEs and FAMAs, which, together with variation of the stomatal development in the entry division, implies that SPCH might have contributed greatly to the diversity of stomatal development. Based on the above, we proposed a model for the correlation between the evolution of stomatal development and the genes involved in this developmental process in land plants. PMID:24244399

  10. The Drosophila jing gene is a downstream target in the Trachealess/Tango tracheal pathway.

    PubMed

    Morozova, Tatiana; Hackett, Joanne; Sedaghat, Yalda; Sonnenfeld, Margaret

    2010-12-01

    Primary branching in the Drosophila trachea is regulated by the Trachealess (Trh) and Tango (Tgo) basic helix-loop-helix-PAS (bHLH-PAS) heterodimers, the POU protein Drifter (Dfr)/Ventral Veinless (Vvl), and the Pointed (Pnt) ETS transcription factor. The jing gene encodes a zinc finger protein also required for tracheal development. Three Trh/Tgo DNA-binding sites, known as CNS midline elements, in 1.5 kb of jing 5? cis-regulatory sequence (jing1.5) previously suggested a downstream role for jing in the pathway. Here, we show that jing is a direct downstream target of Trh/Tgo and that Vvl and Pnt are also involved in jing tracheal activation. In vivo lacZ enhancer detection assays were used to identify cis-regulatory elements mediating embryonic expression patterns of jing. A 2.8-kb jing enhancer (jing2.8) drove lacZ expression in all tracheal cell lineages, the CNS midline and Engrailed-positive segmental stripes, mimicking endogenous jing expression. A 1.3-kb element within jing2.8 drove expression that was restricted to Engrailed-positive CNS midline cells and segmental ectodermal stripes. Surprisingly, jing1.5-lacZ expression was restricted to tracheal fusion cells despite the presence of consensus DNA-binding sites for bHLH-PAS, ETS, and POU domain transcription factors. Given the absence of Trh/Tgo DNA-binding sites in the jing1.3 enhancer, these results are consistent with previous observations suggesting a combinatorial basis to Trh-/Tgo-mediated transcriptional regulation in the trachea. PMID:21061019

  11. A Comprehensive Profile of ChIP-Seq-Based Olig2 Target Genes in Motor Neuron Progenitor Cells Suggests the Possible Involvement of Olig2 in the Pathogenesis of Amyotrophic Lateral Sclerosis

    PubMed Central

    Satoh, Jun-ichi; Asahina, Naohiro; Kitano, Shouta; Kino, Yoshihiro

    2015-01-01

    BACKGROUND Amyotrophic lateral sclerosis (ALS) is an intractable neurodegenerative disease that primarily affects motor neurons in the cerebral cortex and the spinal cord. Recent evidence indicates that dysfunction of oligodendrocytes is implicated in the pathogenesis of ALS. The basic helix–loop–helix (bHLH) transcription factor Olig2 plays a pivotal role in the development of both motor neurons and oligodendrocytes in the progenitor of motor neuron (pMN) domain of the spinal cord, supporting evidence for the shared motor neuron/oligodendrocyte lineage. However, a comprehensive profile of Olig2 target genes in pMNs and oligodendrocyte progenitor cells (OPCs) with relevance to the pathogenesis of ALS remains to be characterized. METHODS By analyzing the ChIP-Seq datasets numbered SRP007566 and SRP015333 with the Strand NGS program, we identified genome-wide Olig2 target genes in pMNs and OPCs, followed by molecular network analysis using three distinct bioinformatics tools. RESULTS We identified 5966 Olig2 target genes in pMNs, including Nkx2.2, Pax6, Irx3, Ngn2, Zep2 (Cip1), Trp3, Mnx1 (Hb9), and Cdkn1a, and 1553 genes in OPCs. The genes closely related to the keyword “alternative splicing” were enriched in the set of 740 targets overlapping between pMNs and OPCs. Furthermore, approximately one-third of downregulated genes in purified motor neurons of presymptomatic mutant SOD1 transgenic mice and in lumbar spinal cord tissues of ALS patients corresponded to Olig2 target genes in pMNs. Molecular networks of Olig2 target genes indicate that Olig2 regulates a wide range of genes essential for diverse neuronal and glial functions. CONCLUSIONS These observations lead to a hypothesis that aberrant regulation of Olig2 function, by affecting biology of both motor neurons and oligodendrocytes, might be involved in the pathogenesis of ALS. PMID:26023283

  12. Angiopoietin-2 Is a Direct Transcriptional Target of TAL1, LYL1 and LMO2 in Endothelial Cells

    PubMed Central

    Chalhoub, Elias; Dohet, Christiane; Pinet, Valérie; Couttet, Philippe; Mathieu, Danièle

    2012-01-01

    The two related basic helix–loop-helix, TAL1 and LYL1, and their cofactor LIM-only-2 protein (LMO2) are present in blood and endothelial cells. While their crucial role in early hematopoiesis is well established, their function in endothelial cells and especially in angiogenesis is less understood. Here, we identified ANGIOPOIETIN-2 (ANG-2), which encodes a major regulator of angiogenesis, as a direct transcriptional target of TAL1, LYL1 and LMO2. Knockdown of any of the three transcription factors in human blood and lymphatic endothelial cells caused ANG-2 mRNA and protein down-regulation. Transient transfections showed that the full activity of the ANG-2 promoter required the integrity of a highly conserved Ebox-GATA composite element. Accordingly, chromatin immunoprecipitation assays demonstrated that TAL1, LYL1, LMO2 and GATA2 occupied this region of ANG-2 promoter in human endothelial cells. Furthermore, we showed that LMO2 played a central role in assembling TAL1-E47, LYL1-LYL1 or/and LYL1-TAL1 dimers with GATA2. The resulting complexes were able to activate endogenous ANG-2 expression in endothelial cells as well as in non-endothelial cells. Finally, we showed that ANG-2 gene activation during angiogenesis concurred with the up-regulation of TAL1 and LMO2. Altogether, we identified ANG-2 as a bona fide target gene of LMO2-complexes with TAL1 and/or LYL1, highlighting a new function of the three hematopoietic factors in the endothelial lineage. PMID:22792348

  13. Id1 Deficiency Protects against Tumor Formation in Apc(Min/+) Mice but Not in a Mouse Model of Colitis-Associated Colon Cancer.

    PubMed

    Zhang, Ning; Subbaramaiah, Kotha; Yantiss, Rhonda K; Zhou, Xi Kathy; Chin, Yvette; Benezra, Robert; Dannenberg, Andrew J

    2015-04-01

    Different mechanisms contribute to the development of sporadic, hereditary and colitis-associated colorectal cancer. Inhibitor of DNA binding/differentiation (Id) proteins act as dominant-negative antagonists of basic helix-loop-helix transcription factors. Id1 is a promising target for cancer therapy, but little is known about its role in the development of colon cancer. We used immunohistochemistry to demonstrate that Id1 is overexpressed in human colorectal adenomas and carcinomas, whether sporadic or syndromic. Furthermore, elevated Id1 levels were found in dysplasia and colon cancer arising in patients with inflammatory bowel disease. Because levels of PGE2 are also elevated in both colitis and colorectal neoplasia, we determined whether PGE2 could induce Id1. PGE2 via EP4 stimulated protein kinase A activity resulting in enhanced pCREB-mediated Id1 transcription in human colonocytes. To determine the role of Id1 in carcinogenesis, two mouse models were used. Consistent with the findings in humans, Id1 was overexpressed in tumors arising in both Apc(Min) (/+) mice, a model of familial adenomatous polyposis, and in experimental colitis-associated colorectal neoplasia. Id1 deficiency led to significant decrease in the number of intestinal tumors in Apc(Min) (/+) mice and prolonged survival. In contrast, Id1 deficiency did not affect the number or size of tumors in the model of colitis-associated colorectal neoplasia, likely due to exacerbation of colitis associated with Id1 loss. Collectively, these results suggest that Id1 plays a role in gastrointestinal carcinogenesis. Our findings also highlight the need for different strategies to reduce the risk of colitis-associated colorectal cancer compared with sporadic or hereditary colorectal cancer. PMID:25623217

  14. Distribution and function of splash, an achaete-scute homolog in the adult olfactory organ of the Caribbean spiny lobster Panulirus argus

    PubMed Central

    Tadesse, Tizeta; Schmidt, Manfred; Walthall, William W.; Tai, Phang C.; Derby, Charles D.

    2011-01-01

    achaete-scute complex (ASC) genes, which encode basic helix-loop-helix transcription factors, regulate embryonic and adult neurogenesis in many animals. In adult arthropods, including crustaceans, ASC homologs have been identified but rarely functionally characterized. We took advantage of the recently identified crustacean homolog, splash (spiny lobster achaete scute homolog), in the olfactory organ of the Caribbean spiny lobster Panulirus argus to examine its role in adult neurogenesis. We tested the hypothesis that splash is associated with but not restricted to sensory neuron formation in the olfactory organ, the antennular lateral flagellum (LF), of adult spiny lobsters. We demonstrated splash labeling in epithelial cells across LF developmental zones (i.e., proliferation and mature zones), in auxiliary cells surrounding dendrites of olfactory receptor neurons (ORNs), and in immature and mature ORNs, but not in granulocytes or chromatophores. Since ORN proliferation varies with molt stage, we examined splash expression across molt stages and found that molt stage affected splash expression in the ORN mature zone but not in the proliferation zone. In vivo incorporation of bromodeoxyuridine (BrdU) showed no correlation in the cellular pattern of splash expression and BrdU labeling. The intensity of splash labeling was dramatically enhanced in the proliferation zones following LF damage, suggesting enhanced splash expression during repair and/or regeneration. We conclude that splash is not closely associated with the formation of sensory neurons under normal physiological conditions, and we propose that splash is involved in repair and regeneration. We also propose that splash has additional roles other than neurogenesis in adult crustaceans. PMID:21394934

  15. Steroid Receptor Co-activator Is Required for Juvenile Hormone Signal Transduction through a bHLH-PAS Transcription Factor, Methoprene Tolerant*

    PubMed Central

    Zhang, Zhaolin; Xu, Jingjing; Sheng, Zhentao; Sui, Yipeng; Palli, Subba R.

    2011-01-01

    Metamorphosis in insects is regulated by juvenile hormone (JH) and ecdysteroids. The mechanism of 20-hydroxyecdysone (20E), but not of JH action, is well understood. A basic helix-loop-helix (bHLH)-Per-Arnt-Sim (PAS) family member, methoprene tolerant (Met), plays an important role in JH action. Microarray analysis and RNA interference (RNAi) were used to identify 69 genes that require Met for their hydroprene-regulated expression in the red flour beetle, Tribolium castaneum. Quantitative real time PCR analysis confirmed microarray data for 13 of the 16 hydroprene-response genes tested. The members of the bHLH-PAS family often function as heterodimers to regulate gene expression and Met is a member of this family. To determine whether other members of the bHLH-PAS family are required for the expression of JH-response genes, we employed RNAi to knockdown the expression of all 11 members of the bHLH-PAS family and studied the expression of JH-response genes in RNAi insects. These studies showed that besides Met, another member of this family, steroid receptor co-activator (SRC) is required for the expression of 15 JH-response genes tested. Moreover, studies in JH responsive Aag-2 cells revealed that Aedes aegypti homologues of both Met and SRC are required for the expression of the JH-response gene, kr-h1, and SRC is required for expression of ecdysone-response genes. These data suggest the steroid receptor co-activator plays key roles in both JH and 20E action suggesting that this may be an important molecule that mediates cross-talk between JH and 20E to prevent metamorphosis. PMID:21190938

  16. A role for PacMYBA in ABA-regulated anthocyanin biosynthesis in red-colored sweet cherry cv. Hong Deng (Prunus avium L.).

    PubMed

    Shen, Xinjie; Zhao, Kai; Liu, Linlin; Zhang, Kaichun; Yuan, Huazhao; Liao, Xiong; Wang, Qi; Guo, Xinwei; Li, Fang; Li, Tianhong

    2014-05-01

    The MYB transcription factors and plant hormone ABA have been suggested to play a role in fruit anthocyanin biosynthesis, but supporting genetic evidence has been lacking in sweet cherry. The present study describes the first functional characterization of an R2R3-MYB transcription factor, PacMYBA, from red-colored sweet cherry cv. Hong Deng (Prunus avium L.). Transient promoter assays demonstrated that PacMYBA physically interacted with several anthocyanin-related basic helix-loop-helix (bHLH) transcription factors to activate the promoters of PacDFR, PacANS and PacUFGT, which are thought to be involved in anthocyanin biosynthesis. Furthermore, the immature seeds of transgenic Arabidopsis plants overexpressing PacMYBA exhibited ectopic pigmentation. Silencing of PacMYBA, using a Tobacco rattle virus (TRV)-induced gene silencing technique, resulted in sweet cherry fruit that lacked red pigment. ABA treatment significantly induced anthocyanin accumulation, while treatment with the ABA biosynthesis inhibitor nordihydroguaiaretic acid (NDGA) blocked anthocyanin production. PacMYBA expression peaked after 2 h of pre-incubation in ABA and was 15.2-fold higher than that of sweet cherries treated with NDGA. The colorless phenotype was also observed in the fruits silenced in PacNCED1, which encodes a key enzyme in the ABA biosynthesis pathway. The endogenous ABA content as well as the transcript levels of six structural genes and PacMYBA in PacNCED1-RNAi (RNA interference) fruit were significantly lower than in the TRV vector control fruit. These results suggest that PacMYBA plays an important role in ABA-regulated anthocyanin biosynthesis and ABA is a signal molecule that promotes red-colored sweet cherry fruit accumulating anthocyanin. PMID:24443499

  17. Pbx and Prdm1a transcription factors differentially regulate subsets of the fast skeletal muscle program in zebrafish.

    PubMed

    Yao, Zizhen; Farr, Gist H; Tapscott, Stephen J; Maves, Lisa

    2013-06-15

    The basic helix-loop-helix factor Myod initiates skeletal muscle differentiation by directly and sequentially activating sets of muscle differentiation genes, including those encoding muscle contractile proteins. We hypothesize that Pbx homeodomain proteins direct Myod to a subset of its transcriptional targets, in particular fast-twitch muscle differentiation genes, thereby regulating the competence of muscle precursor cells to differentiate. We have previously shown that Pbx proteins bind with Myod on the promoter of the zebrafish fast muscle gene mylpfa and that Pbx proteins are required for Myod to activate mylpfa expression and the fast-twitch muscle-specific differentiation program in zebrafish embryos. Here we have investigated the interactions of Pbx with another muscle fiber-type regulator, Prdm1a, a SET-domain DNA-binding factor that directly represses mylpfa expression and fast muscle differentiation. The prdm1a mutant phenotype, early and increased fast muscle differentiation, is the opposite of the Pbx-null phenotype, delayed and reduced fast muscle differentiation. To determine whether Pbx and Prdm1a have opposing activities on a common set of genes, we used RNA-seq analysis to globally assess gene expression in zebrafish embryos with single- and double-losses-of-function for Pbx and Prdm1a. We find that the levels of expression of certain fast muscle genes are increased or approximately wild type in pbx2/4-MO;prdm1a-/- embryos, suggesting that Pbx activity normally counters the repressive action of Prdm1a for a subset of the fast muscle program. However, other fast muscle genes require Pbx but are not regulated by Prdm1a. Thus, our findings reveal that subsets of the fast muscle program are differentially regulated by Pbx and Prdm1a. Our findings provide an example of how Pbx homeodomain proteins act in a balance with other transcription factors to regulate subsets of a cellular differentiation program. PMID:23789105

  18. Pbx and Prdm1a transcription factors differentially regulate subsets of the fast skeletal muscle program in zebrafish

    PubMed Central

    Yao, Zizhen; Farr,, Gist H.; Tapscott, Stephen J.; Maves, Lisa

    2013-01-01

    Summary The basic helix–loop–helix factor Myod initiates skeletal muscle differentiation by directly and sequentially activating sets of muscle differentiation genes, including those encoding muscle contractile proteins. We hypothesize that Pbx homeodomain proteins direct Myod to a subset of its transcriptional targets, in particular fast-twitch muscle differentiation genes, thereby regulating the competence of muscle precursor cells to differentiate. We have previously shown that Pbx proteins bind with Myod on the promoter of the zebrafish fast muscle gene mylpfa and that Pbx proteins are required for Myod to activate mylpfa expression and the fast-twitch muscle-specific differentiation program in zebrafish embryos. Here we have investigated the interactions of Pbx with another muscle fiber-type regulator, Prdm1a, a SET-domain DNA-binding factor that directly represses mylpfa expression and fast muscle differentiation. The prdm1a mutant phenotype, early and increased fast muscle differentiation, is the opposite of the Pbx-null phenotype, delayed and reduced fast muscle differentiation. To determine whether Pbx and Prdm1a have opposing activities on a common set of genes, we used RNA-seq analysis to globally assess gene expression in zebrafish embryos with single- and double-losses-of-function for Pbx and Prdm1a. We find that the levels of expression of certain fast muscle genes are increased or approximately wild type in pbx2/4-MO;prdm1a?/? embryos, suggesting that Pbx activity normally counters the repressive action of Prdm1a for a subset of the fast muscle program. However, other fast muscle genes require Pbx but are not regulated by Prdm1a. Thus, our findings reveal that subsets of the fast muscle program are differentially regulated by Pbx and Prdm1a. Our findings provide an example of how Pbx homeodomain proteins act in a balance with other transcription factors to regulate subsets of a cellular differentiation program. PMID:23789105

  19. Failure to Target RANKL Signaling Through p38-MAPK Results in Defective Osteoclastogenesis in the Microphthalmia Cloudy-Eyed Mutant.

    PubMed

    Carey, Heather A; Bronisz, Agnieszka; Cabrera, Jennifer; Hildreth, Blake E; Cuitiño, Maria; Fu, Qi; Ahmad, Asrar; Toribio, Ramiro E; Ostrowski, Michael C; Sharma, Sudarshana M

    2016-03-01

    The Microphthalmia-associated transcription factor (MITF) is a basic helix-loop-helix leucine zipper family factor that is essential for terminal osteoclast differentiation. Previous work demonstrates that phosphorylation of MITF by p38 MAPK downstream of Receptor Activator of NFkB Ligand (RANKL) signaling is necessary for MITF activation in osteoclasts. The spontaneous Mitf cloudy eyed (ce) allele results in production of a truncated MITF protein that lacks the leucine zipper and C-terminal end. Here we show that the Mitf(ce) allele leads to a dense bone phenotype in neonatal mice due to defective osteoclast differentiation. In response to RANKL stimulation, in vitro osteoclast differentiation was impaired in myeloid precursors derived from neonatal or adult Mitf(ce/ce) mice. The loss of the leucine zipper domain in Mitf(ce/ce) mice does not interfere with the recruitment of MITF/PU.1 complexes to target promoters. Further, we have mapped the p38 MAPK docking site within the region deleted in Mitf(ce) . This interaction is necessary for the phosphorylation of MITF by p38 MAPK. Site-directed mutations in the docking site interfered with the interaction between MITF and its co-factors FUS and BRG1. MITF-ce fails to recruit FUS and BRG1 to target genes, resulting in decreased expression of target genes and impaired osteoclast function. These results highlight the crucial role of signaling dependent MITF/p38 MAPK interactions in osteoclast differentiation. J. Cell. Physiol. 231: 630-640, 2016. © 2015 Wiley Periodicals, Inc. PMID:26218069

  20. Phylotypic expression of the bHLH genes Neurogenin2, Neurod, and Mash1 in the mouse embryonic forebrain.

    PubMed

    Osório, Joana; Mueller, Thomas; Rétaux, Sylvie; Vernier, Philippe; Wullimann, Mario F

    2010-03-15

    In the anamniote model animals, zebrafish and Xenopus laevis, highly comparable early forebrain expression patterns of proneural basic helix-loop-helix (bHLH) genes relevant for neurogenesis (atonal homologs, i.e., neurogenins/NeuroD and achaete-scute homologs, i.e., Ascl/ash) were previously revealed during a particular period of development (zebrafish: 3 days; frog: stage 48). Neurogenins/NeuroD on the one hand and Ascl1/ash1 on the other hand exhibit essentially mutually exclusive spatial patterns, probably reflecting different positional information received within the neural tube, and appear to underlie glutamatergic versus GABAergic neuronal differentiation, respectively. Significant data suggest that similar complementary localizations of these proneural genes and corresponding differentiation pathways also exist in the mouse, the prominent mammalian model. The present article reports on detailed mouse brain bHLH gene expression patterns to fill existing gaps in the identification of expression domains, especially outside the telencephalon. Clearly, there are strong similarities in the complementarity of territories expressing Ascl1/Mash 1 versus neurogenins/NeuroD in the entire mouse forebrain, except for the pretectal alar plate and basal plate of prosomeres 1-3. The analysis substantiates localization of neurogenins/NeuroD in the pallium, eminentia thalami, and dorsal thalamus, and expression of Ascl1/Mash 1 in the striatal and septal subpallium, preoptic region, ventral thalamus, and hypothalamus, which is highly similar to the situation described in Xenopus and zebrafish. Thus, all three vertebrate model species display a "phylotypic stage or period" corresponding to a temporally and spatially defined control of neurogenesis during forebrain development, ultimately resulting in the differentiation of distinct populations of glutamatergic versus GABAergic neurons. PMID:20058311

  1. bHLH106 Integrates Functions of Multiple Genes through Their G-Box to Confer Salt Tolerance on Arabidopsis

    PubMed Central

    Ahmad, Aftab; Niwa, Yasuo; Goto, Shingo; Ogawa, Takeshi; Shimizu, Masanori; Suzuki, Akane; Kobayashi, Kyoko; Kobayashi, Hirokazu

    2015-01-01

    An activation-tagging methodology was applied to dedifferentiated calli of Arabidopsis to identify new genes involved in salt tolerance. This identified salt tolerant callus 8 (stc8) as a gene encoding the basic helix-loop-helix transcription factor bHLH106. bHLH106-knockout (KO) lines were more sensitive to NaCl, KCl, LiCl, ABA, and low temperatures than the wild-type. Back-transformation of the KO line rescued its phenotype, and over-expression (OX) of bHLH106 in differentiated plants exhibited tolerance to NaCl. Green fluorescent protein (GFP) fused with bHLH106 revealed that it was localized to the nucleus. Prepared bHLH106 protein was subjected to electrophoresis mobility shift assays against E-box sequences (5'-CANNTG-3'). The G-box sequence 5'-CACGTG-3' had the strongest interaction with bHLH106. bHLH106-OX lines were transcriptomically analyzed, and resultant up- and down-regulated genes selected on the criterion of presence of a G-box sequence. There were 198 genes positively regulated by bHLH106 and 36 genes negatively regulated; these genes possessed one or more G-box sequences in their promoter regions. Many of these genes are known to be involved in abiotic stress response. It is concluded that bHLH106 locates at a branching point in the abiotic stress response network by interacting directly to the G-box in genes conferring salt tolerance on plants. PMID:25978450

  2. An ABA down-regulated bHLH transcription repressor gene, bHLH129 regulates root elongation and ABA response when overexpressed in Arabidopsis

    PubMed Central

    Tian, Hainan; Guo, Hongyan; Dai, Xuemei; Cheng, Yuxin; Zheng, Kaijie; Wang, Xiaoping; Wang, Shucai

    2015-01-01

    Plant hormone abscisic acid (ABA) plays a crucial role in modulating plant responses to environmental stresses. Basic helix-loop-helix (bHLH) transcription factors are one of the largest transcription factor families that regulate multiple aspects of plant growth and development, as well as of plant metabolism in Arabidopsis. Several bHLH transcription factors have been shown to be involved in the regulation of ABA signaling. We report here the characterization of bHLH129, a bHLH transcription factor in Arabidopsis. We found that the expression level of bHLH129 was reduced in response to exogenously applied ABA, and elevated in the ABA biosynthesis mutant aba1-5. Florescence observation of transgenic plants expressing bHLH129-GFP showed that bHLH129 was localized in the nucleus, and transient expression of bHLH129 in protoplasts inhibited reporter gene expression. When expressed in Arabidopsis under the control of the 35S promoter, bHLH129 promoted root elongation, and the transgenic plants were less sensitivity to ABA in root elongation assays. Quantitative RT-PCR results showed that ABA response of several genes involved in ABA signaling, including ABI1, SnRK2.2, SnRK2.3 and SnRK2.6 were altered in the transgenic plants overexpressing bHLH129. Taken together, our study suggests that bHLH129 is a transcription repressor that negatively regulates ABA response in Arabidopsis. PMID:26625868

  3. ZINC FINGER OF ARABIDOPSIS THALIANA12 (ZAT12) Interacts with FER-LIKE IRON DEFICIENCY-INDUCED TRANSCRIPTION FACTOR (FIT) Linking Iron Deficiency and Oxidative Stress Responses.

    PubMed

    Le, Cham Thi Tuyet; Brumbarova, Tzvetina; Ivanov, Rumen; Stoof, Claudia; Weber, Eva; Mohrbacher, Julia; Fink-Straube, Claudia; Bauer, Petra

    2016-01-01

    Plants grown under iron (Fe)-deficient conditions induce a set of genes that enhance the efficiency of Fe uptake by the roots. In Arabidopsis (Arabidopsis thaliana), the central regulator of this response is the basic helix-loop-helix transcription factor FER-LIKE IRON DEFICIENCY-INDUCED TRANSCRIPTION FACTOR (FIT). FIT activity is regulated by protein-protein interactions, which also serve to integrate external signals that stimulate and possibly inhibit Fe uptake. In the search of signaling components regulating FIT function, we identified ZINC FINGER OF ARABIDOPSIS THALIANA12 (ZAT12), an abiotic stress-induced transcription factor. ZAT12 interacted with FIT, dependent on the presence of the ethylene-responsive element-binding factor-associated amphiphilic repression motif. ZAT12 protein was found expressed in the root early differentiation zone, where its abundance was modulated in a root layer-specific manner. In the absence of ZAT12, FIT expression was upregulated, suggesting a negative effect of ZAT12 on Fe uptake. Consistently, zat12 loss-of-function mutants had higher Fe content than the wild type at sufficient Fe. We found that under Fe deficiency, hydrogen peroxide (H2O2) levels were enhanced in a FIT-dependent manner. FIT protein, in turn, was stabilized by H2O2 but only in the presence of ZAT12, showing that H2O2 serves as a signal for Fe deficiency responses. We propose that oxidative stress-induced ZAT12 functions as a negative regulator of Fe acquisition. A model where H2O2 mediates the negative regulation of plant responses to prolonged stress might be applicable to a variety of stress conditions. PMID:26556796

  4. Characterization of species-specific genes regulated by E2-2 in human plasmacytoid dendritic cells.

    PubMed

    Cheng, Menglan; Zhang, Xuyuan; Yu, Haisheng; Du, Peishuang; Plumas, Joël; Chaperot, Laurance; Su, Lishan; Zhang, Liguo

    2015-01-01

    Dendritic cells (DCs) are sentinels of the immune system and comprise two distinct subsets: conventional DCs (cDCs) and plasmacytoid DCs (pDCs). Human pDCs are distinguished from mouse pDCs phenotypically and functionally. Basic helix-loop-helix protein E2-2 is defined as an essential transcription factor for mouse pDC development, cell fate maintenance and gene programe. It is unknown whether E2-2 regulation contributes to this species-specific difference. Here we investigated the function of E2-2 in human pDCs and screened human-specific genes regulated by E2-2. Reduced E2-2 expression in human pDC cell line GEN2.2 resulted in diminished IFN-? production in response to CpG but elevated antigen presentation capacity. Gene expression profiling showed that E2-2 silence down-regulated pDC signature genes but up-regulated cDC signature genes. Thirty human-specific genes regulated by E2-2 knockdown were identified. Among these genes, we confirmed that expression of Siglec-6 was inhibited by E2-2. Further more, Siglec-6 was expressed at a higher level on a human pDC subset with drastically lower expression of E2-2. Collectively, these results highlight that E2-2 modulates pDC function in a species-specific manner, which may provide insights for pDC development and functions. PMID:26182859

  5. Jasmonic acid promotes degreening via MYC2/3/4- and ANAC019/055/072-mediated regulation of major chlorophyll catabolic genes.

    PubMed

    Zhu, Xiaoyu; Chen, Junyi; Xie, Zuokun; Gao, Jiong; Ren, Guodong; Gao, Shan; Zhou, Xin; Kuai, Benke

    2015-11-01

    Degreening caused by rapid chlorophyll (Chl) degradation is a characteristic event during green organ senescence or maturation. Pheophorbide a oxygenase gene (PAO) encodes a key enzyme of Chl degradation, yet its transcriptional regulation remains largely unknown. Using yeast one-hybrid screening, coupled with in vitro and in vivo assays, we revealed that Arabidopsis MYC2/3/4 basic helix-loop-helix proteins directly bind to PAO promoter. Overexpression of the MYCs significantly enhanced the transcriptional activity of PAO promoter in Arabidopsis protoplasts, and methyl jasmonate (MeJA) treatment greatly induced PAO expression in wild-type Arabidopsis plants, but the induction was abolished in myc2 myc3 myc4. In addition, MYC2/3/4 proteins could promote the expression of another Chl catabolic enzyme gene, NYC1, as well as a key regulatory gene of Chl degradation, NYE1/SGR1, by directly binding to their promoters. More importantly, the myc2 myc3 myc4 triple mutant showed a severe stay-green phenotype, whereas the lines overexpressing the MYCs showed accelerated leaf yellowing upon MeJA treatment. These results suggest that MYC2/3/4 proteins may mediate jasmonic acid (JA)-induced Chl degradation by directly activating these Chl catabolic genes (CCGs). Three NAC family proteins, ANAC019/055/072, downstream from MYC2/3/4 proteins, could also directly promote the expression of a similar set of CCGs (NYE1/SGR1, NYE2/SGR2 and NYC1) during Chl degradation. In particular, anac019 anac055 anac072 triple mutant displayed a severe stay-green phenotype after MeJA treatment. Finally, we revealed that MYC2 and ANAC019 may interact with each other and synergistically enhance NYE1 expression. Together, our study reveals a hierarchical and coordinated regulatory network of JA-induced Chl degradation. PMID:26407000

  6. Decoding c-Myc networks of cell cycle and apoptosis regulated genes in a transgenic mouse model of papillary lung adenocarcinomas.

    PubMed

    Ciribilli, Yari; Singh, Prashant; Spanel, Reinhard; Inga, Alberto; Borlak, Jürgen

    2015-10-13

    The c-Myc gene codes for a basic-helix-loop-helix-leucine zipper transcription factor protein and is reported to be frequently over-expressed in human cancers. Given that c-Myc plays an essential role in neoplastic transformation we wished to define its activity in lung cancer and therefore studied its targeted expression to respiratory epithelium in a transgenic mouse disease model. Using histological well-defined tumors, transcriptome analysis identified novel c-Myc responsive cell cycle and apoptosis genes that were validated as direct c-Myc targets using EMSA, Western blotting, gene reporter and ChIP assays.Through computational analyses c-Myc cooperating transcription factors emerged for repressed and up-regulated genes in cancer samples, namely Klf7, Gata3, Sox18, p53 and Elf5 and Cebp?, respectively. Conversely, at promoters of genes regulated in transgenic but non-carcinomatous lung tissue enriched binding sites for c-Myc, Hbp1, Hif1 were observed. Bioinformatic analysis of tumor transcriptomic data revealed regulatory gene networks and highlighted mortalin and moesin as master regulators while gene reporter and ChIP assays in the H1299 lung cancer cell line as well as cross-examination of published ChIP-sequence data of 7 human and 2 mouse cell lines provided strong evidence for the identified genes to be c-Myc targets. The clinical significance of findings was established by evaluating expression of orthologous proteins in human lung cancer. Taken collectively, a molecular circuit for c-Myc-dependent cellular transformation was identified and the network analysis broadened the perspective for molecularly targeted therapies. PMID:26427040

  7. A minimal regulatory region maintains constitutive expression of the max gene.

    PubMed Central

    Peters, M A; Sollenberger, K G; Kao, T L; Taparowsky, E J

    1997-01-01

    Max is a basic helix-loop-helix/leucine zipper protein that forms heterodimers with the Myc family of proteins to promote cell growth and with the Mad/Mxi1 family of proteins to inhibit cell growth. The role of Max as the obligate binding partner for these two protein families necessitates the observed constitutive expression and relatively long half-life of the max mRNA under a variety of growth conditions. In this study, we have used the chicken max gene to map DNA elements maintaining max gene expression in vertebrate cells. We have identified a minimal regulatory region (MRR) that resides within 115 bp of the max translation initiation site and that possesses an overall structure typical of TATA-less promoters. Within the MRR are two consensus binding sites for Sp1, a ubiquitously expressed transcription factor that plays a role in the expression of many constitutive genes. Interestingly, we show that direct binding by Sp1 to these sites is not required for MRR-mediated transcription. Instead, the integrity of a 20-bp DNA element in the MRR is required for transcriptional activity, as is the interaction of this DNA element with a 90-kDa cellular protein. Our data suggest that it is the persistence of this 90-kDa protein in vertebrate cells which drives max gene expression, insulates the max promoter from the dramatic changes in transcription that accompany cell growth and development, and ensures that adequate levels of Max will be available to facilitate the function of the Myc, Mad, and Mxi1 families of proteins. PMID:9032230

  8. Definition of a minimal domain of the dioxin receptor that is associated with Hsp90 and maintains wild type ligand binding affinity and specificity.

    PubMed

    Coumailleau, P; Poellinger, L; Gustafsson, J A; Whitelaw, M L

    1995-10-20

    The dioxin receptor is a cytoplasmic basic helix-loop-helix/Per-Arnt-Sim homology (bHLH/PAS) protein known to bind planar polycyclic ligands including polycyclic aromatic hydrocarbons, benzoflavones, heterocyclic amines, and halogenated aromatic hydrocarbons, e.g. dioxins. Ligand-induced activation of the dioxin receptor initiates a process whereby the receptor is transformed into a nuclear transcription factor complex with a specific bHLH/PAS partner protein, Arnt. In analogy to the glucocorticoid receptor, the latent dioxin receptor is found associated with the molecular chaperone hsp90. We have defined and isolated a minimal ligand binding domain of the dioxin receptor from the central PAS region, comprising of amino acids 230 to 421, and found this domain to interact with hsp90 in vitro. Expression of the minimal ligand binding domain in wheat germ lysates or bacteria, systems which harbor hsp90 homologs unable to interact with the glucocorticoid or dioxin receptors, resulted in non-ligand binding forms of this minimal 230 to 421 fragment. Importantly, affinity of the minimal ligand binding domain for dioxin was similar to the affinity inherent in the full-length dioxin receptor, and a profile of ligand structures which specifically bound the minimal ligand binding domain was found to be conserved between this domain and the native receptor. These experiments show that the minimal ligand binding domain maintains the quantitative and qualitative aspects of ligand binding exhibited by the full-length receptor, implying that the central ligand binding pocket may exist to accommodate all classes of specific dioxin receptor ligands, and that this pocket is critically dependent upon hsp90 for its ligand binding conformation. PMID:7559670

  9. Down-Regulating the Expression of 53 Soybean Transcription Factor Genes Uncovers a Role for SPEECHLESS in Initiating Stomatal Cell Lineages during Embryo Development.

    PubMed

    Danzer, John; Mellott, Eric; Bui, Anhthu Q; Le, Brandon H; Martin, Patrick; Hashimoto, Meryl; Perez-Lesher, Jeanett; Chen, Min; Pelletier, Julie M; Somers, David A; Goldberg, Robert B; Harada, John J

    2015-07-01

    We used an RNA interference screen to assay the function of 53 transcription factor messenger RNAs (mRNAs) that accumulate specifically within soybean (Glycine max) seed regions, subregions, and tissues during development. We show that basic helix-loop-helix (bHLH) transcription factor genes represented by Glyma04g41710 and its paralogs are required for the formation of stoma in leaves and stomatal precursor complexes in mature embryo cotyledons. Phylogenetic analysis indicates that these bHLH transcription factor genes are orthologous to Arabidopsis (Arabidopsis thaliana) SPEECHLESS (SPCH) that initiate asymmetric cell divisions in the leaf protoderm layer and establish stomatal cell lineages. Soybean SPCH (GmSPCH) mRNAs accumulate primarily in embryo, seedling, and leaf epidermal layers. Expression of Glyma04g41710 under the control of the SPCH promoter rescues the Arabidopsis spch mutant, indicating that Glyma04g41710 is a functional ortholog of SPCH. Developing soybean embryos do not form mature stoma, and stomatal differentiation is arrested at the guard mother cell stage. We analyzed the accumulation of GmSPCH mRNAs during soybean seed development and mRNAs orthologous to MUTE, FAMA, and inducer of C-repeat/dehydration responsive element-binding factor expression1/scream2 that are required for stoma formation in Arabidopsis. The mRNA accumulation patterns provide a potential explanation for guard mother cell dormancy in soybean embryos. Our results suggest that variation in the timing of bHLH transcription factor gene expression can explain the diversity of stomatal forms observed during plant development. PMID:25963149

  10. PYK10, a beta-glucosidase located in the endoplasmatic reticulum, is crucial for the beneficial interaction between Arabidopsis thaliana and the endophytic fungus Piriformospora indica.

    PubMed

    Sherameti, Irena; Venus, Yvonne; Drzewiecki, Corinna; Tripathi, Swati; Dan, Vipin Mohan; Nitz, Inke; Varma, Ajit; Grundler, Florian M; Oelmüller, Ralf

    2008-05-01

    Piriformospora indica, an endophyte of the Sebacinaceae family, promotes growth and seed production of many plant species, including Arabidopsis. Growth of a T-DNA insertion line in PYK10 is not promoted and the plants do not produce more seeds in the presence of P. indica, although their roots are more colonized by the fungus than wild-type roots. Overexpression of PYK10 mRNA did not affect root colonization and the response to the fungus. PYK10 codes for a root- and hypocotyl-specific beta-glucosidase/myrosinase, which is implicated to be involved in plant defences against herbivores and pathogens. Expression of PYK10 is activated by the basic helix-loop-helix domain containing transcription factor NAI1, and two Arabidopsis lines with mutations in the NAI1 gene show the same response to P. indica as the PYK10 insertion line. PYK10 transcript and PYK10 protein levels are severely reduced in a NAI1 mutant, indicating that PYK10 and not the transcription factor NAI1 is responsible for the response to the fungus. In wild-type roots, the message level for a leucine-rich repeat protein LRR1, but not for plant defensin 1.2 (PDF1.2), is upregulated in the presence of P. indica. In contrast, in lines with reduced PYK10 levels the PDF1.2, but not LRR1, message level is upregulated in the presence of the fungus. We propose that PYK10 restricts root colonization by P. indica, which results in the repression of defence responses and the upregulation of responses leading to a mutualistic interaction between the two symbiotic partners. PMID:18248598

  11. Bone Morphogenetic Protein Inhibition Promotes Neurological Recovery After Intraventricular Hemorrhage

    PubMed Central

    Dummula, Krishna; Vinukonda, Govindaiah; Chu, Philip; Xing, Yiping; Hu, Furong; Mailk, Sabrina; Csiszar, Anna; Chua, Caroline; Mouton, Peter; Kayton, Robert J.; Brumberg, Joshua C.; Bansal, Rashmi; Ballabh, Praveen

    2011-01-01

    Intraventricular hemorrhage (IVH) results in neural cell-death and white matter injury in premature infants. No therapeutic strategy is currently available against this disorder. Bone-morphogenetic-protein (BMP) signaling suppresses oligodendrocyte development through basic-helix-loop-helix (bHLH) transcription factors and promotes astrocytosis. Therefore, we hypothesized that IVH in premature newborns initiates degeneration and maturation arrest of oligodendrocyte lineage, and that BMP inhibition alleviates hypomyelination, gliosis, and motor impairment in the survivors of IVH. To test the hypotheses, a rabbit model of IVH was used where premature rabbit pups (E29) are treated with intraperitoneal glycerol at 2 h age to induce IVH; and the pups with IVH exhibit hypomyelination and gliosis at two weeks of postnatal age. Maturation of oligodendrocyte lineage was evaluated by specific markers; and the expression of bHLH transcription factors was assessed. BMP levels were measured in both premature rabbit pups and autopsy materials from premature infants. Recombinant human noggin was used to suppress BMP action; and neurobehavioral performance, myelination and gliosis were assessed in noggin-treated pups compared to untreated controls. We found that IVH resulted in apoptosis and reduced proliferation of oligodendrocyte progenitors, as well as arrested maturation of pre-oligodendrocytes in rabbits. BMP4 levels were significantly elevated in both rabbit pups and human premature infants with IVH compared to controls. Importantly, BMP inhibition by recombinant human noggin restored the levels of phospho-Smad 1/5/8, Olig2 transcription factor, oligodendrocyte maturation, myelination, astrocyte morphology and motor function in premature pups with IVH. Hence, BMP inhibition might enhance neurological recovery in premature infants with IVH. PMID:21865450

  12. An ABA down-regulated bHLH transcription repressor gene, bHLH129 regulates root elongation and ABA response when overexpressed in Arabidopsis.

    PubMed

    Tian, Hainan; Guo, Hongyan; Dai, Xuemei; Cheng, Yuxin; Zheng, Kaijie; Wang, Xiaoping; Wang, Shucai

    2015-01-01

    Plant hormone abscisic acid (ABA) plays a crucial role in modulating plant responses to environmental stresses. Basic helix-loop-helix (bHLH) transcription factors are one of the largest transcription factor families that regulate multiple aspects of plant growth and development, as well as of plant metabolism in Arabidopsis. Several bHLH transcription factors have been shown to be involved in the regulation of ABA signaling. We report here the characterization of bHLH129, a bHLH transcription factor in Arabidopsis. We found that the expression level of bHLH129 was reduced in response to exogenously applied ABA, and elevated in the ABA biosynthesis mutant aba1-5. Florescence observation of transgenic plants expressing bHLH129-GFP showed that bHLH129 was localized in the nucleus, and transient expression of bHLH129 in protoplasts inhibited reporter gene expression. When expressed in Arabidopsis under the control of the 35S promoter, bHLH129 promoted root elongation, and the transgenic plants were less sensitivity to ABA in root elongation assays. Quantitative RT-PCR results showed that ABA response of several genes involved in ABA signaling, including ABI1, SnRK2.2, SnRK2.3 and SnRK2.6 were altered in the transgenic plants overexpressing bHLH129. Taken together, our study suggests that bHLH129 is a transcription repressor that negatively regulates ABA response in Arabidopsis. PMID:26625868

  13. A novel bHLH transcription factor PebHLH35 from Populus euphratica confers drought tolerance through regulating stomatal development, photosynthesis and growth in Arabidopsis

    SciTech Connect

    Dong, Yan; Wang, Congpeng; Han, Xiao; Tang, Sha; Liu, Sha; Xia, Xinli; Yin, Weilun

    2014-07-18

    Highlights: • PebHLH35 is firstly cloned from Populus euphratica and characterized its functions. • PebHLH35 is important for earlier seedling establishment and vegetative growth. • PebHLH35 enhances tolerance to drought by regulating growth. • PebHLH35 enhances tolerance to drought by regulating stomatal development. • PebHLH35 enhances tolerance to drought by regulating photosynthesis and transpiration. - Abstract: Plant basic helix-loop-helix (bHLH) transcription factors (TFs) are involved in a variety of physiological processes including the regulation of plant responses to various abiotic stresses. However, few drought-responsive bHLH family members in Populus have been reported. In this study, a novel bHLH gene (PebHLH35) was cloned from Populus euphratica. Expression analysis in P. euphratica revealed that PebHLH35 was induced by drought and abscisic acid. Subcellular localization studies using a PebHLH35-GFP fusion showed that the protein was localized to the nucleus. Ectopic overexpression of PebHLH35 in Arabidopsis resulted in a longer primary root, more leaves, and a greater leaf area under well-watered conditions compared with vector control plants. Notably, PebHLH35 overexpression lines showed enhanced tolerance to water-deficit stress. This finding was supported by anatomical and physiological analyses, which revealed a reduced stomatal density, stomatal aperture, transpiration rate, and water loss, and a higher chlorophyll content and photosynthetic rate. Our results suggest that PebHLH35 functions as a positive regulator of drought stress responses by regulating stomatal density, stomatal aperture, photosynthesis and growth.

  14. Evolving gene regulation networks into cellular networks guiding adaptive behavior: an outline how single cells could have evolved into a centralized neurosensory system

    PubMed Central

    Fritzsch, Bernd; Jahan, Israt; Pan, Ning; Elliott, Karen L.

    2014-01-01

    Understanding the evolution of the neurosensory system of man, able to reflect on its own origin, is one of the major goals of comparative neurobiology. Details of the origin of neurosensory cells, their aggregation into central nervous systems and associated sensory organs, their localized patterning into remarkably different cell types aggregated into variably sized parts of the central nervous system begin to emerge. Insights at the cellular and molecular level begin to shed some light on the evolution of neurosensory cells, partially covered in this review. Molecular evidence suggests that high mobility group (HMG) proteins of pre-metazoans evolved into the definitive Sox [SRY (sex determining region Y)-box] genes used for neurosensory precursor specification in metazoans. Likewise, pre-metazoan basic helix-loop-helix (bHLH) genes evolved in metazoans into the group A bHLH genes dedicated to neurosensory differentiation in bilaterians. Available evidence suggests that the Sox and bHLH genes evolved a cross-regulatory network able to synchronize expansion of precursor populations and their subsequent differentiation into novel parts of the brain or sensory organs. Molecular evidence suggests metazoans evolved patterning gene networks early and not dedicated to neuronal development. Only later in evolution were these patterning gene networks tied into the increasing complexity of diffusible factors, many of which were already present in pre-metazoans, to drive local patterning events. It appears that the evolving molecular basis of neurosensory cell development may have led, in interaction with differentially expressed patterning genes, to local network modifications guiding unique specializations of neurosensory cells into sensory organs and various areas of the central nervous system. PMID:25416504

  15. Transcriptomic Analysis of the Underground Renewal Buds during Dormancy Transition and Release in ‘Hangbaishao’ Peony (Paeonia lactiflora)

    PubMed Central

    Zhang, Jiaping; Wang, Guanqun; Li, Xin; Xia, Yiping

    2015-01-01

    Paeonia lactiflora is one of the most famous species of herbaceous peonies with gorgeous flowers. Bud dormancy is a crucial developmental process that allows P. lactiflora to survive unfavorable environmental conditions. However, little information is available on the molecular mechanism of the bud dormancy in P. lactiflora. We performed de novo transcriptome sequencing using the Illumina RNA sequencing platform for the underground renewal buds of P. lactiflora ‘Hangbaishao’ to study the molecular mechanism underlying its bud dormancy transition (the period from endodormancy to ecodormancy) and release (the period from ecodormancy to bud elongation and sprouting). Approximately 300 million high-quality clean reads were generated and assembled into 207,827 (mean length = 828 bp) and 51,481 (mean length = 1250 bp) unigenes using two assembly methods named “Trinity” and “Trinity+PRICE”, respectively. Based on the data obtained by the latter method, 32,316 unigenes were annotated by BLAST against various databases. Approximately 1,251 putative transcription factors were obtained, of which the largest number of unique transcripts belonged to the basic helix-loop-helix protein (bHLH) transcription factor family, and five of the top ten highly expressed transcripts were annotated as dehydrin (DHN). A total of 17,705 simple sequence repeat (SSR) motifs distributed in 13,797 sequences were obtained. The budbreak morphology, levels of indole-3-acetic acid (IAA) and abscisic acid (ABA), and activities of guaiacol peroxidase (POD) and catalase (CAT) were observed. The expression of 20 interested unigenes, which annotated as DHN, heat shock protein (HSP), histone, late elongated hypocotyl (LHY), and phytochrome (PHY), and so on, were also analyzed. These studies were based on morphological, physiological, biochemical, and molecular levels and provide comprehensive insight into the mechanism of dormancy transition and release in P. lactiflora. Transcriptome dataset can be highly valuable for future investigation on gene expression networks in P. lactiflora as well as research on dormancy in other non-model perennial horticultural crops of commercial significance. PMID:25790307

  16. Differential levels of Neurod establish zebrafish endocrine pancreas cell fates.

    PubMed

    Dalgin, Gökhan; Prince, Victoria E

    2015-06-01

    During development a network of transcription factors functions to differentiate foregut cells into pancreatic endocrine cells. Differentiation of appropriate numbers of each hormone-expressing endocrine cell type is essential for the normal development of the pancreas and ultimately for effective maintenance of blood glucose levels. A fuller understanding of the details of endocrine cell differentiation may contribute to development of cell replacement therapies to treat diabetes. In this study, by using morpholino and gRNA/Cas9 mediated knockdown we establish that differential levels of the basic-helix loop helix (bHLH) transcription factor Neurod are required for the differentiation of distinct endocrine cell types in developing zebrafish. While Neurod plays a role in the differentiation of all endocrine cells, we find that differentiation of glucagon-expressing alpha cells is disrupted by a minor reduction in Neurod levels, whereas differentiation of insulin-expressing beta cells is less sensitive to Neurod depletion. The endocrine cells that arise during embryonic stages to produce the primary islet, and those that arise subsequently during larval stages from the intra-pancreatic duct (IPD) to ultimately contribute to the secondary islets, show similar dependence on differential Neurod levels. Intriguingly, Neurod-deficiency triggers premature formation of endocrine precursors from the IPD during early larval stages. However, the Neurod-deficient endocrine precursors fail to differentiate appropriately, and the larvae are unable to maintain normal glucose levels. In summary, differential levels of Neurod are required to generate endocrine pancreas subtypes from precursors during both embryonic and larval stages, and Neurod function is in turn critical to endocrine function. PMID:25797153

  17. Transcription Factor SCL Is Required for c-kit Expression and c-Kit Function in Hemopoietic Cells

    PubMed Central

    Krosl, Gorazd; He, Gang; Lefrancois, Martin; Charron, Frédéric; Roméo, Paul-Henri; Jolicoeur, Paul; Kirsch, Ilan R.; Nemer, Mona; Hoang, Trang

    1998-01-01

    In normal hemopoietic cells that are dependent on specific growth factors for cell survival, the expression of the basic helix-loop-helix transcription factor SCL/Tal1 correlates with that of c-Kit, the receptor for Steel factor (SF) or stem cell factor. To address the possibility that SCL may function upstream of c-kit, we sought to modulate endogenous SCL function in the CD34+ hemopoietic cell line TF-1, which requires SF, granulocyte/macrophage colony–stimulating factor, or interleukin 3 for survival. Ectopic expression of an antisense SCL cDNA (as-SCL) or a dominant negative SCL (dn-SCL) in these cells impaired SCL DNA binding activity, and prevented the suppression of apoptosis by SF only, indicating that SCL is required for c-Kit–dependent cell survival. Consistent with the lack of response to SF, the level of c-kit mRNA and c-Kit protein was significantly and specifically reduced in as-SCL– or dn-SCL– expressing cells. c-kit mRNA, c-kit promoter activity, and the response to SF were rescued by SCL overexpression in the antisense or dn-SCL transfectants. Furthermore, ectopic c-kit expression in as-SCL transfectants is sufficient to restore cell survival in response to SF. Finally, enforced SCL in the pro–B cell line Ba/F3, which is both SCL and c-kit negative is sufficient to induce c-Kit and SF responsiveness. Together, these results indicate that c-kit, a gene that is essential for the survival of primitive hemopoietic cells, is a downstream target of the transcription factor SCL. PMID:9687522

  18. Induction of transcripts derived from promoter III of the acetyl-CoA carboxylase-alpha gene in mammary gland is associated with recruitment of SREBP-1 to a region of the proximal promoter defined by a DNase I hypersensitive site.

    PubMed Central

    Barber, Michael C; Vallance, Amanda J; Kennedy, Helen T; Travers, Maureen T

    2003-01-01

    ACC-alpha (acetyl-CoA carboxylase-alpha), a key regulator of fatty-acid metabolism, is encoded by mRNAs transcribed from three promoters, PI, PII and PIII, in the ovine genome. Enhanced expression of transcripts encoded by PIII in mammary gland during lactation is associated with alterations in chromatin structure that result in the detection of two DNase I hypersensitive sites, upstream of the start site. The most proximal site, located between -190 and -10, is characterized by the presence of an inverted-CCAAT box, C2 at -167, and E-boxes, E1 and E2, at -151 and -46. Deletion of these motifs, which bind nuclear factor-Y and upstream stimulatory factors respectively in gel-shift assays, attenuates the activity of luciferase reporter constructs in transfected cells. Chromatin immunoprecipitation demonstrated that these transcription factors were associated with PIII in vivo in both lactating and non-lactating mammary tissues. The basic helix-loop-helix-leucine zipper transcription factor, SREBP-1 (sterol-regulated-element-binding protein-1), transactivated PIII reporter constructs in transfected HC11 mammary cells, and this was dependent on the presence of E1, but not on C2 or E2. SREBP-1 was only associated with PIII in chromatin from lactating animals, which was coincident with a 4-fold increase in the precursor (125 kDa) form of SREBP-1 in microsomes and the appearance of the mature form (68 kDa) in the nucleus. SREBP-1 motifs are also present in the proximal region of PII, which is also induced in lactation. This indicates that SREBP-1 is a major developmental regulator of the programme of lipid synthesis de novo in the lactating mammary gland. PMID:12871210

  19. Changes in the expression of DNA-binding/differentiation protein inhibitors in neurons and glial cells of the gerbil hippocampus following transient global cerebral ischemia.

    PubMed

    Lee, Jae-Chul; Chen, Bai Hui; Cho, Jeong-Hwi; Kim, In Hye; Ahn, Ji Hyeon; Park, Joon Ha; Tae, Hyun-Jin; Cho, Geum-Sil; Yan, Bing Chun; Kim, Dae Won; Hwang, In Koo; Park, Jinseu; Lee, Yun Lyul; Choi, Soo Young; Won, Moo-Ho

    2015-04-01

    Inhibitors of DNA-binding/differentiation (ID) proteins bind to basic helix?loop?helix (bHLH) transcription factors, including those that regulate differentiation and cell?cycle progression during development, and regulate gene transcription. However, little is known about the role of ID proteins in the brain under transient cerebral ischemic conditions. In the present study, we examined the effects of ischemia?reperfusion (I-R) injury on the immunoreactivity and protein levels of IDs 1?4 in the gerbil hippocampus proper Cornu Ammonis regions CA1?3 following 5 min of transient cerebral ischemia. Strong ID1 immunoreactivity was detected in the nuclei of pyramidal neurons in the hippocampal CA1?3 regions; immunoreactivity was significantly changed following I-R in the CA1 region, but not in the CA2/3 region. Five days following I-R, ID1 immunoreactivity was not detected in the CA1 pyramidal neurons. ID1 immunoreactivity was detected only in GABAergic interneurons in the ischemic CA1 region. Weak ID4 immunoreactivity was detected in non?pyramidal cells, and immunoreactivity was again only changed in the ischemic CA1 region. Five days following I-R, strong ID4 immunoreactivity was detected in non?pyramidal cells, which were identified as microglia, and not astrocytes, in the ischemic CA1 region. Furthermore, changes in the protein levels of ID1 and ID4 in the ischemic CA1 region studied by western blot were consistent with patterns of immunoreactivity. In summary, these results indicate that immunoreactivity and protein levels of ID1 and ID4 are distinctively altered following transient cerebral ischemia only in the CA1 region, and that the changes in ID1 and ID4 expression may relate to the ischemia?induced delayed neuronal death. PMID:25503067

  20. BASIC: A Model Partnership for Art Education.

    ERIC Educational Resources Information Center

    Paterakis, Angela G.

    1989-01-01

    Describes Basic Art Support in the Curriculum (BASIC), an art program initiated in 1983 by the art department at the School of the Art Institute of Chicago. Reports that BASIC is a model professional development program for art teachers and lists activities carried out by BASIC. (SLM)

  1. Basic Color Terms in Estonian Sign Language

    ERIC Educational Resources Information Center

    Hollman, Liivi; Sutrop, Urmas

    2011-01-01

    The article is written in the tradition of Brent Berlin and Paul Kay's theory of basic color terms. According to this theory there is a universal inventory of eleven basic color categories from which the basic color terms of any given language are always drawn. The number of basic color terms varies from 2 to 11 and in a language having a fully…

  2. Basic Course Communication Annual. Volume 1.

    ERIC Educational Resources Information Center

    Hugenberg, Lawrence W., Ed.

    This annual collection contains essays relating to the history of basic communication courses, offers insights into basic course pedagogy, and discusses the administration of multisectioned basic communication courses. Papers in the collection include: "The Basic Course in Speech Communication: An Historical Perspective" (Pamela L. Gray); "What We…

  3. Basic statistics in cell biology.

    PubMed

    Vaux, David L

    2014-01-01

    The physicist Ernest Rutherford said, "If your experiment needs statistics, you ought to have done a better experiment." Although this aphorism remains true for much of today's research in cell biology, a basic understanding of statistics can be useful to cell biologists to help in monitoring the conduct of their experiments, in interpreting the results, in presenting them in publications, and when critically evaluating research by others. However, training in statistics is often focused on the sophisticated needs of clinical researchers, psychologists, and epidemiologists, whose conclusions depend wholly on statistics, rather than the practical needs of cell biologists, whose experiments often provide evidence that is not statistical in nature. This review describes some of the basic statistical principles that may be of use to experimental biologists, but it does not cover the sophisticated statistics needed for papers that contain evidence of no other kind. PMID:25000992

  4. Basic Science and The NIH

    PubMed Central

    Varmus, Harold

    1994-01-01

    The following is an edited version of the Keynote Speech delivered at the Annual Meeting of the American Society for Cell Biology by Harold Varmus, Director of the National Institutes of Health. The address, entitled Basic Science and the NIH, was given at the opening of the meeting in New Orleans on December 11, 1993. It was Varmus' first public policy talk as NIH Director. PMID:8049519

  5. BLAS- BASIC LINEAR ALGEBRA SUBPROGRAMS

    NASA Technical Reports Server (NTRS)

    Krogh, F. T.

    1994-01-01

    The Basic Linear Algebra Subprogram (BLAS) library is a collection of FORTRAN callable routines for employing standard techniques in performing the basic operations of numerical linear algebra. The BLAS library was developed to provide a portable and efficient source of basic operations for designers of programs involving linear algebraic computations. The subprograms available in the library cover the operations of dot product, multiplication of a scalar and a vector, vector plus a scalar times a vector, Givens transformation, modified Givens transformation, copy, swap, Euclidean norm, sum of magnitudes, and location of the largest magnitude element. Since these subprograms are to be used in an ANSI FORTRAN context, the cases of single precision, double precision, and complex data are provided for. All of the subprograms have been thoroughly tested and produce consistent results even when transported from machine to machine. BLAS contains Assembler versions and FORTRAN test code for any of the following compilers: Lahey F77L, Microsoft FORTRAN, or IBM Professional FORTRAN. It requires the Microsoft Macro Assembler and a math co-processor. The PC implementation allows individual arrays of over 64K. The BLAS library was developed in 1979. The PC version was made available in 1986 and updated in 1988.

  6. Basic Radar Altimetry Toolbox & Tutorial

    NASA Astrophysics Data System (ADS)

    Rosmorduc, Vinca; Benveniste, Jerome; Breebaart, Leo; Bronner, Emilie; Dinardo, Salvatore; Earith, Didier; Lucas, Bruno Manuel; Niejmeier, Sander; Picot, Nicolas

    2010-12-01

    The Basic Radar Altimetry Toolbox is an "all-altimeter" collection of tools, tutorials and documents designed to facilitate the use of radar altimetry data, including the last mission launched, CryoSat. It has been available from April 2007, and had been demonstrated during training courses and scientific meetings. Nearly 1200 people downloaded it (as of end of June 2010), with many "newcomers" to altimetry among them. Users' feedbacks, developments in altimetry, and practice, showed that new interesting features could be added. Some have been added and/or improved in version 2. Others are ongoing, some are in discussion. The Basic Radar Altimetry Toolbox is able: - to read most distributed radar altimetry data, from ERS-1 & 2, Topex/Poseidon, Geosat Follow-on, Jason- 1, Envisat, Jason- 2, CryoSat and also the future Saral and Sentinel 3 missions, - to perform some processing, data editing and statistic, - and to visualize the results. It can be used at several levels/several ways: - as a data reading tool, with APIs for C, Fortran, Matlab and IDL - as processing/extraction routines, through the on-line command mode - as an educational and a quick-look tool both, with the graphical user interface As part of the Toolbox, a Radar Altimetry Tutorial gives general information about altimetry, the technique involved and its applications, as well as an overview of past, present and future missions, including information on how to access data, additional software and documentation. It also presents a series of data use cases, covering all uses of altimetry over ocean, cryosphere and land, showing the basic methods for some of the most frequent manners of using altimetry data. BRAT is developed under contract with ESA and CNES. It is available at http://www.altimetry.info and http://earth.esa.int/brat/

  7. [Basic science and applied science].

    PubMed

    Pérez-Tamayo, R

    2001-01-01

    A lecture was presented by the author at the Democratic Opinion Forum on Health Teaching and Research, organized by Mexico's National Health Institutes Coordinating Office, at National Cardiology Institute "Ignacio Chavez", where he presented a critical review of the conventional classification of basic and applied science, as well as his personal view on health science teaching and research. According to the author, "well-conducted science" is that "generating reality-checked knowledge" and "mis-conducted science" is that "unproductive or producing 'just lies' and 'non-fundable'. To support his views, the author reviews utilitarian and pejorative definitions of science, as well as those of committed and pure science, useful and useless science, and practical and esoterical science, as synonyms of applied and basic science. He also asserts that, in Mexico, "this classification has been used in the past to justify federal funding cutbacks to basic science, allegedly because it is not targeted at solving 'national problems' or because it was not relevant to priorities set in a given six-year political administration period". Regarding health education and research, the author asserts that the current academic programs are inefficient and ineffective; his proposal to tackle these problems is to carry out a solid scientific study, conducted by a multidisciplinary team of experts, "to design the scientific researcher curricula from recruitment of intelligent young people to retirement or death". Performance assessment of researchers would not be restricted to publication of papers, since "the quality of scientific work and contribution to the development of science is not reflected by the number of published papers". The English version of this paper is available at: http://www.insp.mx/salud/index.html PMID:11547597

  8. Back to Basics: Inhaled Anesthesia.

    PubMed

    Spruce, Lisa

    2015-10-01

    The administration of inhalational anesthesia is a major component of providing care for patients undergoing operative or other invasive procedures. The perioperative nurse should understand the effects of anesthesia and actions of anesthetic agents (eg, unconsciousness, analgesia, anesthesia, muscle relaxation) and carefully assess the patient for contraindications to the anesthetic proposed, understand its effect on the patient, and understand how anesthesia affects the care provided. This Back to Basics article provides an overview of inhalational anesthesia and serves as a guide for nurses in the perioperative care of anesthetized patients. PMID:26411822

  9. Basic photovoltaic principles and methods

    SciTech Connect

    Hersch, P.; Zweibel, K.

    1982-02-01

    This book presents a nonmathematical explanation of the theory and design of photovoltaic (PV) solar cells and systems. The basic elements of PV are introduced: the photovoltaic effect, physical aspects of solar cell efficiency, the typical single-crystal silicon solar cell, advances in single-crystal silicon solar cells. This is followed by the designs of systems constructed from individual cells, including possible constructions for putting cells together and the equipment needed for a practical producer of electrical energy. The future of PV is then discussed. (LEW)

  10. Basic Psychiatric Literature: I. Books*†

    PubMed Central

    Woods, Joan B.; Pieper, Sam; Frazier, Shervert H.

    1968-01-01

    Widely varying recommended reading lists for psychiatry residents were obtained from 140 AMA-approved training programs. Approximately 4,000 articles, 2,800 books, and 200 serials were listed. The number of recommendations for each book was counted, and a rank-order determined. A second rank-order was determined from the lists of those eighty-seven programs which indicated that their material covered the “basic” literature; a third rank-order was determined from the number of residents using the lists. All rank-orders agreed on the “most recommended” book and the first eighteen books; there was a 92 percent correlation through the first 453 books. One-third of the “basic” recommendations were for the first 104 books; one-third for the next 349 books, and one-third for the remaining 1,994 books. The subject matter of the first 104 books indicated that the currently most popular subjects in psychiatry are psychoanalytic theories of personality, schizophrenia, psychotherapy, and child psychiatry. A list of the 104 most recommended books is appended. PMID:4874980

  11. Gaia basic angle monitoring system

    NASA Astrophysics Data System (ADS)

    Gielesen, W.; de Bruijn, D.; van den Dool, T.; Kamphues, F.; Meijer, E.; Calvel, B.; Laborie, A.; Monteiro, D.; Coatantiec, C.; Touzeau, S.; Erdmann, M.; Gare, P.

    2012-09-01

    The Gaia mission will create an extraordinarily precise three-dimensional map of more than one billion stars in our Galaxy. The Gaia spacecraft, built by EADS Astrium, is part of ESA's Cosmic Vision programme and scheduled for launch in 2013. Gaia measures the position, distance and motion of stars with an accuracy of 24 micro-arcsec using two telescopes at a fixed mutual angle of 106.5°, named the ‘Basic Angle’. This accuracy requires ultra-high stability, which can only be achieved by using Silicon Carbide for both the optical bench and the telescopes. TNO has developed, built and space qualified the Silicon carbide Basic Angle Monitoring (BAM) on-board metrology system for this mission. The BAM measures the relative motion of Gaia’s telescopes with accuracies in the range of 0.5 micro-arcsec. This is achieved by a system of two laser interferometers able to measure Optical Path Differences (OPD) as small as 1.5 picometer rms. Following a general introduction to the Gaia mission, the Payload Module (PLM) and the use of Silicon Carbide as base material, this presentation will address an overview of the challenges towards the key requirements, design, integration and testing (including space-level qualification) of the Gaia BAM.

  12. Basic definitions. Logarithmic residues and duality.

    E-print Network

    Denham, Graham

    Basic definitions. Logarithmic residues and duality. Normal crossing conditions Residues along plane curves The complete intersection case. Logarithmic differential forms and questions of residues Granger University of Angers, France Logarithmic differential forms and questions of residues. #12;Basic

  13. 5 CFR 300.103 - Basic requirements.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... Basic requirements. (a) Job analysis. Each employment practice...individual agencies, shall be based on a job analysis to identify: (1) The basic...in evaluating candidates. The job analysis may cover a single position...

  14. 5 CFR 300.103 - Basic requirements.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... Basic requirements. (a) Job analysis. Each employment practice...individual agencies, shall be based on a job analysis to identify: (1) The basic...in evaluating candidates. The job analysis may cover a single position...

  15. Bloody Stools in Children (Beyond the Basics)

    MedlinePLUS

    ... adenomatous polyposis (The Basics)" and "Peutz-Jeghers syndrome: Epidemiology, clinical manifestations, and diagnosis" ). In addition, tumors may ... colitis in children (The Basics) Peutz-Jeghers syndrome: Epidemiology, clinical manifestations, and diagnosis Related Searches Anal fissure ...

  16. 32 CFR 37.1240 - Basic research.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ...2012-07-01 false Basic research. 37.1240 Section 37...Part § 37.1240 Basic research. Efforts directed toward...knowledge and understanding in science and engineering, rather...typically is funded within Research, Development, Test and...

  17. 32 CFR 37.1240 - Basic research.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...2013-07-01 false Basic research. 37.1240 Section 37...Part § 37.1240 Basic research. Efforts directed toward...knowledge and understanding in science and engineering, rather...typically is funded within Research, Development, Test and...

  18. 32 CFR 37.1240 - Basic research.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...2010-07-01 false Basic research. 37.1240 Section 37...Part § 37.1240 Basic research. Efforts directed toward...knowledge and understanding in science and engineering, rather...typically is funded within Research, Development, Test and...

  19. 32 CFR 37.1240 - Basic research.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...2011-07-01 false Basic research. 37.1240 Section 37...Part § 37.1240 Basic research. Efforts directed toward...knowledge and understanding in science and engineering, rather...typically is funded within Research, Development, Test and...

  20. Basic Radar Altimetry Toolbox & Tutorial

    NASA Astrophysics Data System (ADS)

    Rosmorduc, Vinca; Benveniste, Jerome; Bronner, Emilie; Dinardo, Salvatore; Lucas, Bruno Manuel; Niejmeier, Sander; Picot, Nicolas; Breebaart, Leo; Earith, Didier

    2010-05-01

    The Basic Radar Altimetry Toolbox is an "all-altimeter" collection of tools, tutorials and documents designed to facilitate the use of radar altimetry data, including the next mission to be launched, CryoSat. It has been available from April 2007, and had been demonstrated during training courses and scientific meetings. About 900 people downloaded it (January 2009), with many "newcomers" to altimetry among them. Users' feedbacks, developments in altimetry, and practice, showed that new interesting features could be added. Some have been added and/or improved in version 2. Others are ongoing, some are in discussion. The Basic Radar Altimetry Toolbox is able: - to read most distributed radar altimetry data, from ERS-1 & 2, Topex/Poseidon, Geosat Follow-on, Jason-1, Envisat, Jason- 2, and the furure CryoSat and Saral missions, - to perform some processing, data editing and statistic, - and to visualize the results. It can be used at several levels/several ways: - as a data reading tool, with APIs for C, Fortran, Matlab and IDL - as processing/extraction routines, through the on-line command mode - as an educational and a quick-look tool, with the graphical user interface As part of the Toolbox, a Radar Altimetry Tutorial gives general information about altimetry, the technique involved and its applications, as well as an overview of past, present and future missions, including information on how to access data and additional software and documentation. It also presents a series of data use cases, covering all uses of altimetry over ocean, cryosphere and land, showing the basic methods for some of the most frequent manners of using altimetry data. Version 2 has been released in April 2009, including, among other improvements, a Mac OS X version, River&Lake data reading capability, full waveform processing and plotting, new plotting capabilities, export in GeoTiff, including a Google Earth export feature, easier export in Ascii, a rethinking of the Graphical user interface and of the software packaging, to make it easier to use. New developments are ongoing, with e.g. improvements of the Display tool (mainly for maps), the inclusion of processing algorithms within the Toolbox. Other developments are envisioned, with particular focus on coastal and hydrology applications. Yet the main incentive stays the users' needs, so all feedbacks are welcomed. BRAT is developed under contract with ESA and CNES. It is available at http://www.altimetry.info and http://earth.esa.int/brat/

  1. Measuring Student Teachers' Basic Psychological Needs

    ERIC Educational Resources Information Center

    Vermeulen, Marjan; Castelijns, Jos; Kools, Quinta; Koster, Bob

    2012-01-01

    In Self-Determination Theory, basic psychological needs for relatedness, autonomy and competence are distinguished. Basic psychological need-fulfilment is considered to be critical for human development and intrinsic motivation. In the Netherlands, the concept of basic psychological need-fulfilment is introduced in the curricula of many teacher…

  2. The RSZ BASIC programming language manual

    NASA Technical Reports Server (NTRS)

    Stattel, R. J.; Niswander, J. K.; Kochhar, A. K.

    1980-01-01

    The RSZ BASIC interactive language is described. The RSZ BASIC interpreter is resident in the Telemetry Data Processor, a system dedicated to the processing and displaying of PCM telemetry data. A series of working examples teaches the fundamentals of RSZ BASIC and shows how to construct, edit, and manage storage of programs.

  3. Basic Vocational Education Teacher Training Manual.

    ERIC Educational Resources Information Center

    Thomas, Larry D.; And Others

    This instructor's guide consists of four modules teacher educators can use in preparing prospective teachers to teach basic vocational education students. The modules cover the following topics: (1) characteristics of basic vocational education students or students at risk for dropping out of high school; (2) program requirements of the basic

  4. A Repeal of the Basic Writing Act.

    ERIC Educational Resources Information Center

    Puma, Vincent D.

    The development of alternative instructional activities for use in the basic writing classroom and a description and analysis of four levels of basic writing are the results of a study of basic writing teaching techniques. The linguistic concepts of immediate and transferred utterances and nominal-verbal pairing, and the work of L. Vygotsky on…

  5. Basic Skills Support in Business and Industry.

    ERIC Educational Resources Information Center

    Byatt, Janet; Davies, Karen

    This guide is designed as a tool for English and Welsh businesses wanting to provide basic skills training for their employees. It provides practical solutions to the problems of identifying employees' basic skills needs and selecting the best model of training delivery to address identified training needs. The introductory section discusses basic

  6. The BASIC Instructional Program Student Manual.

    ERIC Educational Resources Information Center

    Beard, M. H.; Barr, A. V.

    This manual is the student's main source of information about the BASIC Instructional Program (BIP), a "hands-on laboratory" that teaches elementary programming in the BASIC language, and the BASIC language itself. The manual is organized as a reference document for students with no previous programming experience. Three major sections contain (1)…

  7. Basic Communication Course Annual. Volume 8.

    ERIC Educational Resources Information Center

    Newburger, Craig, Ed.

    This volume of an annual collection presents 13 essays relating to instruction in the basic communication course. Six of the essays are on the theme of cultural diversity in the basic course. The essays are: "The Differential Impact of a Basic Public Speaking Course on Perceived Communication Competencies in Class, Work, and Social Contexts"…

  8. Basic Communication Course Annual. Volume 11.

    ERIC Educational Resources Information Center

    Hugenberg, Lawrence W., Ed.

    This volume of an annual collection presents eight essays relating to instruction in the basic communication course. The essays are: "The Basic Communication Course at U.S. Colleges and Universities: VI" (Sherwyn P. Morreale, Michael S. Hanna, Roy M. Berko, and James W. Gibson); "How Basic Course Directors Evaluate Teaching Assistants: Social…

  9. Basic Communication Course Annual. Volume 7.

    ERIC Educational Resources Information Center

    Newburger, Craig, Ed.

    This volume of an annual collection of essays presents seven essays relating to instruction in the basic communication course. The essays are: "Gerald M. Phillips' Devotion to Basic Communication Skills" (Julia T. Wood); "The Basic Course in Organizational Communication: A National Survey" (Donald Treadwell and Ronald L. Applbaum); "Improving Oral…

  10. Operational Amplifier Basics I PHYS 309 Name

    E-print Network

    Herman, Rhett

    Operational Amplifier Basics I PHYS 309 Name: A. Introduction The ubiquitous op amp has the symbol--a voltage follower and an inverting amplifier. The basic images for these are below. The usual practice-inverting input Inverting input Op Amps I-1 #12;Operational Amplifier Basics I PHYS 309 Name: The maximum gain

  11. Operational Amplifier Basics II PHYS 309 Name

    E-print Network

    Herman, Rhett

    Operational Amplifier Basics II PHYS 309 Name: A. Introduction The ubiquitous op amp has the symbol Amplifier Basics II PHYS 309 Name: B. Assignment and writeup: For this lab you are to build two more basic op amp circuits: an inverting amplifier and a voltage summation circuit. These circuits

  12. Coding Basics Reed-Solomon Codes

    E-print Network

    Little, John B.

    Coding Basics Reed-Solomon Codes List Decoding Algorithms Algebraic Codes for Error Control John B B. Little Algebraic Codes for Error Control #12;Coding Basics Reed-Solomon Codes List Decoding Algorithms Outline 1 Coding Basics 2 Reed-Solomon Codes 3 List Decoding Algorithms John B. Little Algebraic

  13. Cryptography and Key Management Basics Erik Zenner

    E-print Network

    Zenner, Erik

    Cryptography and Key Management Basics Erik Zenner Technical University Denmark (DTU) Institute for Mathematics e.zenner@mat.dtu.dk DTU, Oct. 23, 2007 Erik Zenner (DTU-MAT) Cryptography and Key Management Basics DTU, Oct. 23, 2007 1 / 24 #12;Plan for Today 1 Talk 1: Cryptography and Key Management Basics

  14. Fluid Power/Basic Hydraulics. Instructor's Guide.

    ERIC Educational Resources Information Center

    Stanbery, Richard

    This guide is designed to assist industrial vocational instructors in teaching a course on fluid power and basic hydraulics. Covered in the unit on the basics of fluid power and hydraulics are the following topics: the fundamentals of fluid power and hydraulics, basic hydraulic circuits, and servicing a hydraulic jack. The second unit, consisting…

  15. PC Basic Linear Algebra Subroutines

    Energy Science and Technology Software Center (ESTSC)

    1992-03-09

    PC-BLAS is a highly optimized version of the Basic Linear Algebra Subprograms (BLAS), a standardized set of thirty-eight routines that perform low-level operations on vectors of numbers in single and double-precision real and complex arithmetic. Routines are included to find the index of the largest component of a vector, apply a Givens or modified Givens rotation, multiply a vector by a constant, determine the Euclidean length, perform a dot product, swap and copy vectors, andmore »find the norm of a vector. The BLAS have been carefully written to minimize numerical problems such as loss of precision and underflow and are designed so that the computation is independent of the interface with the calling program. This independence is achieved through judicious use of Assembly language macros. Interfaces are provided for Lahey Fortran 77, Microsoft Fortran 77, and Ryan-McFarland IBM Professional Fortran.« less

  16. Basic Facts about the Pion

    NASA Astrophysics Data System (ADS)

    Roberts, Craig

    2015-04-01

    With discovery of the Higgs boson, the Standard Model of Particle Physics became complete. Its formulation and verification are a remarkable story. However, the most important chapter is the least understood. Quantum Chromodynamics (QCD) is that part of the Standard Model which is supposed to describe all of nuclear physics and yet, almost fifty years after the discovery of quarks, we are only just beginning to understand how QCD builds the basic bricks for nuclei: pions, neutrons, protons. QCD is characterised by two emergent phenomena: confinement and dynamical chiral symmetry breaking (DCSB), whose implications are truly extraordinary. This presentation will reveal how DCSB, not the Higgs boson, generates more than 98% of the visible mass in the Universe, explain why confinement guarantees that condensates, those quantities that were commonly viewed as constant mass-scales that fill all spacetime, are instead wholly contained within hadrons; and, with particular focus on the pion, elucidate a range of observable consequences of these phenomena whose measurement is the focus of a vast international experimental programme. This research was supported by U.S. Department of Energy, Office of Science, Office of Nuclear Physics, Contract No. DE-AC02-06CH11357.

  17. Symmetry in the basic sciences

    NASA Astrophysics Data System (ADS)

    Toole, Joseph E.; Jensen, David W.; Rogers, Mark E.; Chernek, Paul J.; Erstfeld, Thomas E.

    1989-04-01

    The basic mathematical theory behind plane symmetry groups is presented. This theory is then applied in classifying the symmetry of bounded figures, frieze patterns and wallpaper patterns. Recently developed algorithms are included to help analyze complex designs. Symmetry operations relevant to 3-D crystallography are discussed. In particular, the seven crystal systems that classify the 32 crystallographic point groups are described. These are then used to construct the Bravais lattices. The role is investigated of symmetry in biological forms. Specifically, work on growth and form of molluscan shells is reviewed with an attempt to explain the consequences of that growth and form to the natural history of the Chambered Nautilus and its ancestors. The central role symmetry has increasingly played in physics is looked at by examining the Principle of Least Action and the invariance of the Lagrangian under a transformation. Noether's Theorem guarantees that a conservation law is associated with each of these symmetries. Examples include the conservation of energy, linear momentum, and angular momentum, as well as the purely quantum mechanical symmetry of invariance under an exchange operation. A brief look at gauge theories is the final example of how symmetry has become a guiding principle in the formulation of new theories.

  18. Basic Cosmic Knowledge, Circa 2010

    NASA Astrophysics Data System (ADS)

    Mimouni, J.

    2010-10-01

    What is the minimum knowledge an educated scientist should fathom about the modern Universe, so as to be the ``l'honnête homme'' of this early 21st century? Thanks on the one hand to great theoretical strides, and on the other hand to a wide array of telescopes and detectors on the ground, as well as a flotilla of space borne like means, a new picture of the Universe have emerged: From a violent one in X and Gamma rays for highly energetic processes, to a warmer one in IR able to penetrate planetary cocoons, to a lukewarm one in microwave to go back to the earliest instants of the Universe, all the way to a quiet radio one (In fact misleadingly calm...) for extragalactic astronomy, each telling its own dedicated account. This exciting story which is unfolding in front of our very eyes is multi-band, multi scales, multi carriers, and there is even large shadowy areas going by the name of Dark Matter and Dark Energy which might constitute 21st century physics! Well, what is thus the knowledge of the cosmos we feel confident about today, and what are its various grey areas? That's `Basic Cosmic Knowledge 2010'' or BCK-2010!.

  19. Virtual cathode microwave devices -- Basics

    SciTech Connect

    Thode, L.E.; Snell, C.M.

    1991-01-01

    Unlike a conventional microwave tube, a virtual-cathode device operates above the space-charge limit where the depth of the space-charge potential can cause electron reflection. The region associated with this electron reflection is referred to as a virtual cathode. Microwaves can be generated through oscillations in the position of the virtual cathode and through the bunching of electrons trapped in a potential well between the real and virtual cathodes. These two mechanisms are competitive. There are three basic classes of virtual cathode devices: (1) reflex triode; (2) reditron and side-shoot vircator; and (3) reflex diode or vircator. The reflex diode is the highest power virtual-cathode device. For the reflex diode the energy exchange between the beam and electromagnetic wave occurs in both the axial and radial directions. In some designs the oscillating-virtual-cathode frequency exceeds the reflexing-electron frequency exceeds the oscillating-virtual-cathode frequency. For the flex diode a periodic disruption in magnetic insulation can modulate the high- frequency microwave power. Overall, particle-in-cell simulation predictions and axial reflex diode experiments are in good agreement. Although frequency stability and phase locking of the reflex diode have been demonstrated, little progress has been made in efficiency enhancement. 58 refs., 11 figs.

  20. Basics in Clinical Medical Nutrition.

    PubMed

    Meier, Rémy F; Forbes, Alastair

    2015-11-01

    Nutrition is a basic requirement for life and plays an important role in health and in disease prevention, but malnutrition is a common event and a cause of increased morbidity and mortality, particularly in patients with disease-related malnutrition showing inflammation and a catabolic state. Malnutrition is often overlooked, and deterioration in the nutritional status following admission to hospital is common. It should be actively pursued by a ubiquitous system of nutrition screening, and full nutritional assessment is required for those found to be at risk. There are simple screening tools which can be used by all health care professionals. Assessment considers body composition, inflammatory status and other aspects of underlying diseases and their functional consequences; it is a more specialist process. It is important to determine the energy and protein needs of each individual patient. Appropriate nutritional intervention can often be offered by the oral route, using food with or without special supplements. When this is insufficient, enteral tube feeding will normally be sufficient, but there is an important subgroup of patients in whom enteral feeding is contraindicated or unsuccessful, and in these patients parenteral nutrition (either total or supplemental) is required. A number of immunonutrients and other special substrates have been shown to be helpful in specific circumstances, but their use is not without potential hazards, and therefore adherence to international guidelines is recommended. PMID:26544878

  1. Basic space sciences in Africa

    NASA Astrophysics Data System (ADS)

    Abiodun, Adigun Ade; Odingo, Richard S.

    Through space applications, a number of social and economic programmes in education, communications, agro-climatology, weather forecasting and remote sensing are being realized within the African continent. Regional and international organizations and agencies such as the African Remote Sensing Council, the Pan-African Telecommunication Union and the United Nations system have been instrumental in making Africa conscious of the impact and implications of space science and technology on its peoples. The above notwithstanding, discernible interests in space research, to date, in Africa, have been limited to the work on the solar system and on interplanetary matters including satellite tracking, and to the joint African-Indian proposal for the establishment of an International Institute for Space Sciences and Electronics (INISSE) and the construction, in Kenya, of a Giant Equatorial Radio Telescope (GERT). During this ``Transport and Communications Decade in Africa,'' Africa's basic space research efforts would need to initially focus on the appropriateness, modification and adaptation of existing technologies for African conditions with a view to providing economic, reliable and functional services for the continent. These should include elements of electronics, communications, structural and tooling industries, and upper-atmosphere research. The experience of and collaborative work with India, Brazil and Argentina, as well as the roles of African scientists, are examined.

  2. Connecting the Circadian Clock with Chemosensation 

    E-print Network

    Chatterjee, Abhishek

    2012-07-16

    in T1 sensillae ............................................................................................. 40 14 Or83b and Gprk2 mutants show no rhythm in spike amplitude................. 41 15 Representative traces of sucrose-evoked single...-helix?loop?helix (bHLH) PER- ARNT-SIM (PAS) partners CLOCK (CLK) and CYCLE (CYC), which bind to E-box (CACGTG) enhancer elements and stimulate transcription of period (per) and timeless (tim) in a time-dependant manner (Fig. 1), along with other key clock...

  3. Energetics of basic karate kata.

    PubMed

    Bussweiler, Jens; Hartmann, Ulrich

    2012-12-01

    Knowledge about energy requirements during exercises seems necessary to develop training concepts in combat sport Karate. It is a commonly held view that the anaerobic lactic energy metabolism plays a key role, but this assumption could not be confirmed so far. The metabolic cost and fractional energy supply of basic Karate Kata (Heian Nidan, Shotokan style) with duration of about 30 s were analyzed. Six male Karateka [mean ± SD (age 29 ± 8 years; height 177 ± 5 cm, body mass 75 ± 9 kg)] with different training experience (advanced athletes, experts, elite athletes) were examined while performing one time and two time continuously the sport-specific movements. During Kata performance oxygen uptake was measured with a portable spirometric device, blood lactate concentrations were examined before and after testing and fractional energy supply was calculated. The results have shown that on average 52 % of the energy supply for one Heian Nidan came from anaerobic alactic metabolism, 25 % from anaerobic lactic and 23 % from aerobic metabolism. For two sequentially executed Heian Nidan and thus nearly doubling the duration, the calculated percentages were 33, 25 and 42 %. Total energy demand for one Kata and two Kata was approximately 61 and 99 kJ, respectively. Despite measured blood lactate concentrations up to 8.1 mmol l(-1), which might suggest a dominance of lactic energy supply, a lactic fraction of only 17-31 % during these relatively short and intense sequences could be found. A heavy use of lactic energy metabolism had to be rejected. PMID:22441830

  4. Auto Mechanics. Performance Objectives. Basic Course.

    ERIC Educational Resources Information Center

    Carter, Thomas G., Sr.

    Several intermediate performance objectives and corresponding criterion measures are listed for each of 14 terminal objectives for a basic automotive mechanics course. The materials were developed for a two-semester course (2 hours daily) designed to provide training in the basic fundamentals in diagnosis and repair including cooling system and…

  5. 1 Internet Basics evolution of the web

    E-print Network

    Verschelde, Jan

    Outline 1 Internet Basics evolution of the web IP addresses and URLs client/server and HTTP 2 and the internet L-18 23 February 2015 1 / 29 #12;networking and the internet markup languages 1 Internet Basics in browser 5 Summary + Assignments Intro to Computer Science (MCS 260) networking and the internet L-18 23

  6. Visual Basic Applications to Physics Teaching

    ERIC Educational Resources Information Center

    Chitu, Catalin; Inpuscatu, Razvan Constantin; Viziru, Marilena

    2011-01-01

    Derived from basic language, VB (Visual Basic) is a programming language focused on the video interface component. With graphics and functional components implemented, the programmer is able to bring and use their components to achieve the desired application in a relatively short time. Language VB is a useful tool in physics teaching by creating…

  7. Workbook, Basic Mathematics and Wastewater Processing Calculations.

    ERIC Educational Resources Information Center

    New York State Dept. of Environmental Conservation, Albany.

    This workbook serves as a self-learning guide to basic mathematics and treatment plant calculations and also as a reference and source book for the mathematics of sewage treatment and processing. In addition to basic mathematics, the workbook discusses processing and process control, laboratory calculations and efficiency calculations necessary in…

  8. Back to the Basics: Kansas City, Missouri

    ERIC Educational Resources Information Center

    Handley, Lawrence R.; Lockwood, Catherine M.; Handley, Nathan

    2004-01-01

    "Back to the Basics" is an innovation of the WETMAAP Program (Wetland Education Through Maps and Aerial Photography) which offers a series of workshops that provide training in basics ecological concepts, technological skills, and methods of interpretation necessary for assessing geography and earth science topics. The precept of the series is to…

  9. Legal Basics for Teachers. Fastback 235.

    ERIC Educational Resources Information Center

    Monks, Robert L.; Proulx, Ernest I.

    This fastback presents some basic legal gidelines for teachers, which if observed will minimize the possibility of lawsuits resulting from incidents occurring in school settings. The following topics are covered: (1) basic legal terminology; (2) reporting child abuse; (3) self-defense; (4) possession and use of controlled substances; (5)…

  10. Basic Theatrical Understanding: Considerations for James Hamilton

    ERIC Educational Resources Information Center

    Carroll, Noel

    2009-01-01

    In this article, the author considers Hamilton's idea of "basic understanding" of a theatrical performance. The author finds it hard to grasp this conception. He worries, although perhaps only on the basis of misunderstanding, that Hamilton's conception of the basic understanding of theatrical performances will not do the work he wants it to do as…

  11. Basic Shop Fundamentals for the Mechanic.

    ERIC Educational Resources Information Center

    Younce, J. R.; And Others

    These self-study materials are a basic course for Marines working as mechanics. The course contains three study units. The first unit explains mechanics' hand tools and their proper care and usage. The second unit introduces the duties of the personnel at a basic level, describes the areas of a typical shop, and deals with shop operations and…

  12. 42 CFR 424.5 - Basic conditions.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 42 Public Health 3 2012-10-01 2012-10-01 false Basic conditions. 424.5 Section 424.5 Public Health CENTERS FOR MEDICARE & MEDICAID SERVICES, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICARE PROGRAM (CONTINUED) CONDITIONS FOR MEDICARE PAYMENT General Provisions § 424.5 Basic conditions. (a) As...

  13. 32 CFR 37.1240 - Basic research.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 32 National Defense 1 2011-07-01 2011-07-01 false Basic research. 37.1240 Section 37.1240 National... TECHNOLOGY INVESTMENT AGREEMENTS Definitions of Terms Used in This Part § 37.1240 Basic research. Efforts... practical application of that knowledge and understanding. It typically is funded within...

  14. 32 CFR 37.1240 - Basic research.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 32 National Defense 1 2010-07-01 2010-07-01 false Basic research. 37.1240 Section 37.1240 National... TECHNOLOGY INVESTMENT AGREEMENTS Definitions of Terms Used in This Part § 37.1240 Basic research. Efforts... practical application of that knowledge and understanding. It typically is funded within...

  15. Premature Reassurance and the Basic Writer.

    ERIC Educational Resources Information Center

    Kiefer, Kathleen E.

    College basic writing teachers involved in student/teacher conferences should be aware of the negative effects that result from premature reassurance, assuring students of success too quickly and/or beyond reasonable expectations. The attitudes of basic writers can be divided into three general categories: (1) those who have always had trouble in…

  16. Basic Communication Course Annual. Volume 12.

    ERIC Educational Resources Information Center

    Hugenberg, Lawrence W., Ed.

    This volume of an annual collection presents seven essays relating to instruction in the basic communication course. The essays are: "The Effects of Praise on Student Motivation in the Basic Communication Course" (B. Scott Titsworth); "The Relationship between a Required Self-Disclosure Speech and Public Speaking Anxiety: Considering Gender…

  17. Basic Chemistry for the Cement Industry.

    ERIC Educational Resources Information Center

    Turner, Mason

    This combined student workbook and instructor's guide contains nine units for inplant classes on basic chemistry for employees in the cement industry. The nine units cover the following topics: chemical basics; measurement; history of cement; atoms; bonding and chemical formulas; solids, liquids, and gases; chemistry of Portland cement…

  18. A Sourcebook for Basic Writing Teachers.

    ERIC Educational Resources Information Center

    Enos, Theresa, Ed.

    Focusing on the sociolinguistic dimensions of literacy, this sourcebook builds upon Mina Shaughnessy's contributions to the study of basic writing by gathering together contemporary research, theory, and practice on the subject. The 39 essays and their authors include: "Defining Basic Writing in Context" and "Perspectives on Legacies and Literacy…

  19. A Basic Marathi-English Dictionary.

    ERIC Educational Resources Information Center

    Berntsen, Maxine; Nimbkar, Jai

    This Marathi-English dictionary is intended for the adult student learning Marathi through the medium of English. It contains approximately 10,000 entries, most of which are basic words from which others can be derived. The words constitute a basic vocabulary, including the current meanings, and excluding obsolete meanings. In some cases, the…

  20. Equivariant Basic Cohomology of Riemannian Foliations

    E-print Network

    Goertsches, Oliver

    2010-01-01

    The basic cohomology of a Riemannian foliation on a complete manifold with all leaves closed is the cohomology of the leaf space. In this paper we introduce various methods to compute the basic cohomology in the presence of both closed and non-closed leaves in the simply-connected case (or more generally for Killing foliations): We show that the total basic Betti number of the union C of the closed leaves is smaller than or equal to the total basic Betti number of the foliated manifold, and we give sufficient conditions for equality. If there is a basic Morse-Bott function with critical set equal to C we can compute the basic cohomology explicitly. Another case in which the basic cohomology can be determined is if the space of leaf closures is a simple, convex polytope. Our results are based on Molino's observation that the existence of non-closed leaves yields a distinguished transverse action on the foliated manifold with fixed point set C. We introduce equivariant basic cohomology of transverse actions in ...

  1. Radiological Dispersion Devices and Basic Radiation Science

    ERIC Educational Resources Information Center

    Bevelacqua, Joseph John

    2010-01-01

    Introductory physics courses present the basic concepts of radioactivity and an overview of nuclear physics that emphasizes the basic decay relationship and the various types of emitted radiation. Although this presentation provides insight into radiological science, it often fails to interest students to explore these concepts in a more rigorous…

  2. Transistor Basics II PHYS 309 Name

    E-print Network

    Herman, Rhett

    Transistor Basics II PHYS 309 Name: A. Introduction The two basic types of transistors have specific functions related to the transistor's ability to regulate the current that flow through so you can immediately tell the type of the transistor. A typical transistor circuit is shown

  3. Basics of Solar Heating & Hot Water Systems.

    ERIC Educational Resources Information Center

    American Inst. of Architects, Washington, DC.

    In presenting the basics of solar heating and hot water systems, this publication is organized from the general to the specific. It begins by presenting functional and operational descriptions of solar heating and domestic hot water systems, outlining the basic concepts and terminology. This is followed by a description of solar energy utilization…

  4. Basic Skills Education: The Dialectics of Reconciliation.

    ERIC Educational Resources Information Center

    Corak, Kitty

    The question of whether basic skills courses belong in higher education is examined through a review of the literature. The following issues are discussed in terms of opposing and supporting positions: (1) economic concerns (recruitment of a wider pool of students necessitate basic skills courses but preserve enrollment levels); (2) academic…

  5. Basic Communication Course Annual. Volume 3.

    ERIC Educational Resources Information Center

    Hugenberg, Lawrence W., Ed.

    This volume of an annual collection of essays relating to instruction in the basic communication course is presented in five sections: (1) Six Approaches to the Introductory Course: A Forum; (2) 1990 Basic Course Committee Award Winning Papers; (3) Instruction in the Introductory Communication Course; (4) Research on the Introductory Communication…

  6. Basic Principles of Animal Science. Reprinted.

    ERIC Educational Resources Information Center

    Florida State Dept. of Education, Tallahassee.

    The reference book is designed to fulfill the need for organized subject matter dealing with basic principles of animal science to be incorporated into the high school agriculture curriculum. The material presented is scientific knowledge basic to livestock production. Five units contain specific information on the following topics: anatomy and…

  7. Industrial Electronics. Performance Objectives. Basic Course.

    ERIC Educational Resources Information Center

    Tiffany, Earl

    Several intermediate performance objectives and corresponding criterion measures are listed for each of 30 terminal objectives for a two-semester (2 hours daily) high school course in basic industrial electronics. The objectives cover instruction in basic electricity including AC-DC theory, magnetism, electrical safety, care and use of hand tools,…

  8. Electronics Technology. Performance Objectives. Basic Course.

    ERIC Educational Resources Information Center

    Campbell, Guy

    Several intermediate performance objectives and corresponding criterion measures are listed for each of 20 terminal objectives for a basic electronics technology course. The materials were developed for a two-semester course (2 hours daily) designed to include instruction in basic electricity and electronic fundamentals, and to develop skills and…

  9. Arts Education and Back to Basics.

    ERIC Educational Resources Information Center

    Dobbs, Stephen M., Ed.

    The document presents 14 essays designed to help art educators understand the nature and scope of basic education and what and how the arts contribute to it. John Goodlad presents a basis for considering the arts as an essential ingredient of schooling. A. Graham Down discusses the concerns of the Council for Basic Education and suggests that arts…

  10. Fuel cell electrolyte membrane with basic polymer

    DOEpatents

    Larson, James M. (Saint Paul, MN); Pham, Phat T. (Little Canada, MN); Frey, Matthew H. (Cottage Grove, MN); Hamrock, Steven J. (Stillwater, MN); Haugen, Gregory M. (Edina, MN); Lamanna, William M. (Stillwater, MN)

    2010-11-23

    The present invention is an electrolyte membrane comprising an acid and a basic polymer, where the acid is a low-volatile acid that is fluorinated and is either oligomeric or non-polymeric, and where the basic polymer is protonated by the acid and is stable to hydrolysis.

  11. Fuel cell electrolyte membrane with basic polymer

    DOEpatents

    Larson, James M.; Pham, Phat T.; Frey, Matthew H.; Hamrock, Steven J.; Haugen, Gregory M.; Lamanna, William M.

    2012-12-04

    The present invention is an electrolyte membrane comprising an acid and a basic polymer, where the acid is a low-volatile acid that is fluorinated and is either oligomeric or non-polymeric, and where the basic polymer is protonated by the acid and is stable to hydrolysis.

  12. Basic English. Specialised Bibliography A8.

    ERIC Educational Resources Information Center

    British Council, London (England). English-Teaching Information Centre.

    This bibliography is divided into four sections. The first section lists books dealing with various aspects of basic English instruction, while the second section cites instructional materials available for basic English teaching. The third section cites English dictionaries, and the final section relevant articles. Entries include both American…

  13. CSC418 / CSCD18 / CSC2504 Basic Lighting and Reflection 8 Basic Lighting and Reflection

    E-print Network

    Toronto, University of

    CSC418 / CSCD18 / CSC2504 Basic Lighting and Reflection 8 Basic Lighting and Reflection Up in the scene. Some of the basic qualitative properties of lighting and object reflectance that we need), and secondary reflections (e.g., light that bounces from one surface to another). Reflectance - Different

  14. Computational modeling of the bHLH domain of the transcription factor TWIST1 and R118C, S144R and K145E mutants

    PubMed Central

    2012-01-01

    Background Human TWIST1 is a highly conserved member of the regulatory basic helix-loop-helix (bHLH) transcription factors. TWIST1 forms homo- or heterodimers with E-box proteins, such as E2A (isoforms E12 and E47), MYOD and HAND2. Haploinsufficiency germ-line mutations of the twist1 gene in humans are the main cause of Saethre-Chotzen syndrome (SCS), which is characterized by limb abnormalities and premature fusion of cranial sutures. Because of the importance of TWIST1 in the regulation of embryonic development and its relationship with SCS, along with the lack of an experimentally solved 3D structure, we performed comparative modeling for the TWIST1 bHLH region arranged into wild-type homodimers and heterodimers with E47. In addition, three mutations that promote DNA binding failure (R118C, S144R and K145E) were studied on the TWIST1 monomer. We also explored the behavior of the mutant forms in aqueous solution using molecular dynamics (MD) simulations, focusing on the structural changes of the wild-type versus mutant dimers. Results The solvent-accessible surface area of the homodimers was smaller on wild-type dimers, which indicates that the cleft between the monomers remained more open on the mutant homodimers. RMSD and RMSF analyses indicated that mutated dimers presented values that were higher than those for the wild-type dimers. For a more careful investigation, the monomer was subdivided into four regions: basic, helix I, loop and helix II. The basic domain presented a higher flexibility in all of the parameters that were analyzed, and the mutant dimer basic domains presented values that were higher than the wild-type dimers. The essential dynamic analysis also indicated a higher collective motion for the basic domain. Conclusions Our results suggest the mutations studied turned the dimers into more unstable structures with a wider cleft, which may be a reason for the loss of DNA binding capacity observed for in vitro circumstances. PMID:22839202

  15. Kidney Stones in Children (Beyond the Basics)

    MedlinePLUS

    ... stones in children (Beyond the Basics) Authors Jodi Smith, MD, MPH F Bruder Stapleton, MD Section Editor ... FRCP Deputy Editor Melanie S Kim, MD Disclosures: Jodi Smith, MD, MPH Nothing to disclose. F Bruder Stapleton, ...

  16. Basic space sciences: The Latin American experience

    NASA Astrophysics Data System (ADS)

    Sahade, Jorge

    The paper reports on the extent basic space science is carried in Latin America and outlines the steps that may be taken to improve the situation. Member of the Carrera del Investigador Científico, CONICET, Argentina.

  17. Basic Research in the United States.

    ERIC Educational Resources Information Center

    Handler, Philip

    1979-01-01

    Presents a discussion of the development of basic research in the U.S. since World War II. Topics include the creation of the federal agencies, physics and astronomy, chemistry, earth science, life science, the environment, and social science. (BB)

  18. Seven Basic Elements of a Safety Program.

    ERIC Educational Resources Information Center

    Oliphant, Richard J.

    1979-01-01

    Outlined are the basic elements of a strong utility employee safety program. The components discussed include: management leadership; assignment of responsibility; maintenance; establishment of safety training; accident record system; medical systems; and personal responsibility of employees. (CS)

  19. Basic Research Needs for Countering Terrorism

    SciTech Connect

    Stevens, W.; Michalske, T.; Trewhella, J.; Makowski, L.; Swanson, B.; Colson, S.; Hazen, T.; Roberto, F.; Franz, D.; Resnick, G.; Jacobson, S.; Valdez, J.; Gourley, P.; Tadros, M.; Sigman, M.; Sailor, M.; Ramsey, M.; Smith, B.; Shea, K.; Hrbek, J.; Rodacy, P.; Tevault, D.; Edelstein, N.; Beitz, J.; Burns, C.; Choppin, G.; Clark, S.; Dietz, M.; Rogers, R.; Traina, S.; Baldwin, D.; Thurnauer, M.; Hall, G.; Newman, L.; Miller, D.; Kung, H.; Parkin, D.; Shuh, D.; Shaw, H.; Terminello, L.; Meisel, D.; Blake, D.; Buchanan, M.; Roberto, J.; Colson, S.; Carling, R.; Samara, G.; Sasaki, D.; Pianetta, P.; Faison, B.; Thomassen, D.; Fryberger, T.; Kiernan, G.; Kreisler, M.; Morgan, L.; Hicks, J.; Dehmer, J.; Kerr, L.; Smith, B.; Mays, J.; Clark, S.

    2002-03-01

    To identify connections between technology needs for countering terrorism and underlying science issues and to recommend investment strategies to increase the impact of basic research on efforts to counter terrorism.

  20. Chronic Cough in Adults (Beyond the Basics)

    MedlinePLUS

    ... of Use ©2016 UpToDate, Inc. Patient information: Chronic cough in adults (Beyond the Basics) Authors Ronald C ... and helps to prevent infection. However, sometimes a cough can become a chronic condition. A chronic cough ...

  1. 32 CFR 292.3 - Basic policy.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... of this program. (1) The provisions of the FOIA, as implemented by 32 CFR part 286 and this part... INFORMATION ACT PROGRAM DEFENSE INTELLIGENCE AGENCY (DIA) FREEDOM OF INFORMATION ACT § 292.3 Basic policy....

  2. 32 CFR 292.3 - Basic policy.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... of this program. (1) The provisions of the FOIA, as implemented by 32 CFR part 286 and this part... INFORMATION ACT PROGRAM DEFENSE INTELLIGENCE AGENCY (DIA) FREEDOM OF INFORMATION ACT § 292.3 Basic policy....

  3. 49 CFR 633.21 - Basic requirement.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ...ADMINISTRATION, DEPARTMENT OF TRANSPORTATION PROJECT MANAGEMENT OVERSIGHT Project Management Plans § 633.21 Basic requirement...capital project, the recipient shall submit a project management plan prepared in accordance with §...

  4. Basics Semigroups Conclusion Introduction to Factorization Theory

    E-print Network

    Ponomarenko, Vadim

    operation, candy. . . Familiar examples: (N0, +), (N, +), (Z, +), (N, ×), (Z, ×) #12;Basics Semigroups. Other things you might like: neutral element, inverses, commutativity, a second operation, candy like: neutral element, inverses, commutativity, a second operation, candy. . . Familiar examples: (N0

  5. 42 CFR 409.30 - Basic requirements.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ...PROGRAM HOSPITAL INSURANCE BENEFITS Requirements for Coverage of Posthospital SNF Care § 409.30 Basic requirements. Posthospital SNF care, including SNF-type care furnished in a hospital or CAH that has a swing-bed...

  6. 42 CFR 409.30 - Basic requirements.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ...PROGRAM HOSPITAL INSURANCE BENEFITS Requirements for Coverage of Posthospital SNF Care § 409.30 Basic requirements. Posthospital SNF care, including SNF-type care furnished in a hospital or CAH that has a swing-bed...

  7. 42 CFR 409.30 - Basic requirements.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ...PROGRAM HOSPITAL INSURANCE BENEFITS Requirements for Coverage of Posthospital SNF Care § 409.30 Basic requirements. Posthospital SNF care, including SNF-type care furnished in a hospital or CAH that has a swing-bed...

  8. 42 CFR 409.30 - Basic requirements.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ...PROGRAM HOSPITAL INSURANCE BENEFITS Requirements for Coverage of Posthospital SNF Care § 409.30 Basic requirements. Posthospital SNF care, including SNF-type care furnished in a hospital or CAH that has a swing-bed...

  9. 42 CFR 409.30 - Basic requirements.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ...PROGRAM HOSPITAL INSURANCE BENEFITS Requirements for Coverage of Posthospital SNF Care § 409.30 Basic requirements. Posthospital SNF care, including SNF-type care furnished in a hospital or CAH that has a swing-bed...

  10. Photovoltaics: Basic Design Principles and Components

    SciTech Connect

    1997-03-01

    This publication will introduce you to the basic design principles and components of PV systems. It will also help you discuss these systems knowledgeably with an equipment supplier or system installer.

  11. 5 CFR 315.904 - Basic requirement.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ...Administrative Personnel OFFICE OF PERSONNEL MANAGEMENT CIVIL SERVICE REGULATIONS CAREER AND CAREER-CONDITIONAL EMPLOYMENT Probation on Initial Appointment to a Supervisory or Managerial Position § 315.904 Basic requirement. (a) An...

  12. 5 CFR 315.904 - Basic requirement.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ...Administrative Personnel OFFICE OF PERSONNEL MANAGEMENT CIVIL SERVICE REGULATIONS CAREER AND CAREER-CONDITIONAL EMPLOYMENT Probation on Initial Appointment to a Supervisory or Managerial Position § 315.904 Basic requirement. (a) An...

  13. 5 CFR 315.904 - Basic requirement.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ...Administrative Personnel OFFICE OF PERSONNEL MANAGEMENT CIVIL SERVICE REGULATIONS CAREER AND CAREER-CONDITIONAL EMPLOYMENT Probation on Initial Appointment to a Supervisory or Managerial Position § 315.904 Basic requirement. (a) An...

  14. 5 CFR 315.904 - Basic requirement.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ...Administrative Personnel OFFICE OF PERSONNEL MANAGEMENT CIVIL SERVICE REGULATIONS CAREER AND CAREER-CONDITIONAL EMPLOYMENT Probation on Initial Appointment to a Supervisory or Managerial Position § 315.904 Basic requirement. (a) An...

  15. 5 CFR 315.904 - Basic requirement.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ...Administrative Personnel OFFICE OF PERSONNEL MANAGEMENT CIVIL SERVICE REGULATIONS CAREER AND CAREER-CONDITIONAL EMPLOYMENT Probation on Initial Appointment to a Supervisory or Managerial Position § 315.904 Basic requirement. (a) An...

  16. 28 CFR 51.52 - Basic standard.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...THE VOTING RIGHTS ACT OF 1965, AS AMENDED Determinations by the Attorney General § 51.52 Basic standard. (a) Surrogate for the court. Section 5 provides for submission of a voting change to the Attorney General as an...

  17. 28 CFR 51.52 - Basic standard.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ...THE VOTING RIGHTS ACT OF 1965, AS AMENDED Determinations by the Attorney General § 51.52 Basic standard. (a) Surrogate for the court. Section 5 provides for submission of a voting change to the Attorney General as an...

  18. 28 CFR 51.52 - Basic standard.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...THE VOTING RIGHTS ACT OF 1965, AS AMENDED Determinations by the Attorney General § 51.52 Basic standard. (a) Surrogate for the court. Section 5 provides for submission of a voting change to the Attorney General as an...

  19. Back to Basics in Business Writing.

    ERIC Educational Resources Information Center

    Duckett, Jasmin

    1988-01-01

    Addresses the need to incorporate basic business writing as an integral part of the business learning process to develop critical thinking skills. Writing can be an invaluable method for enhancing the learning process. (JOW)

  20. 27 CFR 71.45 - Basic permits.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... for Citation § 71.45 Basic permits. Whenever the appropriate TTB officer has reason to believe that... shall issue a citation for the suspension, revocation or annulment of such permit, as the case may be....