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Sample records for positively regulates euchromatic

  1. N-Myc regulates a widespread euchromatic program in the human genome partially independent of its role as a classical transcription factor

    PubMed Central

    Cotterman, Rebecca; Jin, Victor X.; Krig, Sheryl R.; Lemen, Jessica M.; Wey, Alice; Farnham, Peggy J.; Knoepfler, Paul S.

    2009-01-01

    Myc proteins have long been modeled to operate strictly as classical gene specific transcription factors, however we find that N-Myc has a robust role in the human genome in regulating global cellular euchromatin including that of intergenic regions. Strikingly, 90–95% of the total genomic euchromatic marks histone H3 acetylated at lysine 9 and methylated at lysine 4 is N-Myc dependent. However, Myc regulation of transcription, even of genes it directly binds and at which it is required for maintenance of active chromatin, is generally weak. Thus, Myc has a much more potent ability to regulate large domains of euchromatin than to influence transcription of individual genes. Overall, Myc regulation of chromatin in the human genome includes both specific genes, but also expansive genomic domains that invoke functions independent of a classical transcription factor. These findings support a new dual model for Myc chromatin function with important implications for the role of Myc in cancer and stem cell biology, including that of induced pluripotent stem (iPS) cells. PMID:19047142

  2. PHD Finger Recognition of Unmodified Histone H3R2 Links UHRF1 to Regulation of Euchromatic Gene Expression

    SciTech Connect

    E Rajakumara; Z Wang; H Ma; L Hu; H Chen; Y Lin; R Guo; F Wu; H Li; et al.

    2011-12-31

    Histone methylation occurs on both lysine and arginine residues, and its dynamic regulation plays a critical role in chromatin biology. Here we identify the UHRF1 PHD finger (PHD{sub UHRF1}), an important regulator of DNA CpG methylation, as a histone H3 unmodified arginine 2 (H3R2) recognition modality. This conclusion is based on binding studies and cocrystal structures of PHD{sub UHRF1} bound to histone H3 peptides, where the guanidinium group of unmodified R2 forms an extensive intermolecular hydrogen bond network, with methylation of H3R2, but not H3K4 or H3K9, disrupting complex formation. We have identified direct target genes of UHRF1 from microarray and ChIP studies. Importantly, we show that UHRF1's ability to repress its direct target gene expression is dependent on PHD{sub UHRF1} binding to unmodified H3R2, thereby demonstrating the functional importance of this recognition event and supporting the potential for crosstalk between histone arginine methylation and UHRF1 function.

  3. PHD Finger Recognition of Unmodified Histone H3R2 Links UHRF1 to Regulation of Euchromatic Gene Expression

    SciTech Connect

    Rajakumara, Eerappa; Wang, Zhentian; Ma, Honghui; Hu, Lulu; Chen, Hao; Lin, Yan; Guo, Rui; Wu, Feizhen; Li, Haitao; Lan, Fei; Shi, Yujiang Geno; Xu, Yanhui; Patel, Dinshaw J.; Shi, Yang

    2011-08-29

    Histone methylation occurs on both lysine and arginine residues, and its dynamic regulation plays a critical role in chromatin biology. Here we identify the UHRF1 PHD finger (PHD{sub UHRF1}), an important regulator of DNA CpG methylation, as a histone H3 unmodified arginine 2 (H3R2) recognition modality. This conclusion is based on binding studies and cocrystal structures of PHD{sub UHRF1} bound to histone H3 peptides, where the guanidinium group of unmodified R2 forms an extensive intermolecular hydrogen bond network, with methylation of H3R2, but not H3K4 or H3K9, disrupting complex formation. We have identified direct target genes of UHRF1 from microarray and ChIP studies. Importantly, we show that UHRF1's ability to repress its direct target gene expression is dependent on PHD{sub UHRF1} binding to unmodified H3R2, thereby demonstrating the functional importance of this recognition event and supporting the potential for crosstalk between histone arginine methylation and UHRF1 function.

  4. Finishing The Euchromatic Sequence Of The Human Genome

    SciTech Connect

    Rubin, Edward M.; Lucas, Susan; Richardson, Paul; Rokhsar, Daniel; Pennacchio, Len

    2004-09-07

    The sequence of the human genome encodes the genetic instructions for human physiology, as well as rich information about human evolution. In 2001, the International Human Genome Sequencing Consortium reported a draft sequence of the euchromatic portion of the human genome. Since then, the international collaboration has worked to convert this draft into a genome sequence with high accuracy and nearly complete coverage. Here, we report the result of this finishing process.The current genome sequence (Build 35) contains 2.85 billion nucleotides interrupted by only 341 gaps. It covers {approx}99% of the euchromatic genome and is accurate to an error rate of {approx}1 event per 100,000 bases. Many of the remaining euchromatic gaps are associated with segmental duplications and will require focused work with new methods. The near-complete sequence, the first for a vertebrate, greatly improves the precision of biological analyses of the human genome including studies of gene number,birth and death. Notably, the human genome seems to encode only20,000-25,000 protein-coding genes. The genome sequence reported here should serve as a firm foundation for biomedical research in the decades ahead.

  5. Directly transmitted unbalanced chromosome abnormalities and euchromatic variants

    PubMed Central

    Barber, J

    2005-01-01

    In total, 200 families were reviewed with directly transmitted, cytogenetically visible unbalanced chromosome abnormalities (UBCAs) or euchromatic variants (EVs). Both the 130 UBCA and 70 EV families were divided into three groups depending on the presence or absence of an abnormal phenotype in parents and offspring. No detectable phenotypic effect was evident in 23/130 (18%) UBCA families ascertained mostly through prenatal diagnosis (group 1). In 30/130 (23%) families, the affected proband had the same UBCA as other phenotypically normal family members (group 2). In the remaining 77/130 (59%) families, UBCAs had consistently mild consequences (group 3). In the 70 families with established EVs of 8p23.1, 9p12, 9q12, 15q11.2, and 16p11.2, no phenotypic effect was apparent in 38/70 (54%). The same EV was found in affected probands and phenotypically normal family members in 30/70 families (43%) (group 2), and an EV co-segregated with mild phenotypic anomalies in only 2/70 (3%) families (group 3). Recent evidence indicates that EVs involve copy number variation of common paralogous gene and pseudogene sequences that are polymorphic in the normal population and only become visible at the cytogenetic level when copy number is high. The average size of the deletions and duplications in all three groups of UBCAs was close to 10 Mb, and these UBCAs and EVs form the "Chromosome Anomaly Collection" at http://www.ngrl.org.uk/Wessex/collection. The continuum of severity associated with UBCAs and the variability of the genome at the sub-cytogenetic level make further close collaboration between medical and laboratory staff essential to distinguish clinically silent variation from pathogenic rearrangement. PMID:16061560

  6. Phosphatidylethanolamine positively regulates autophagy and longevity

    PubMed Central

    Rockenfeller, P; Koska, M; Pietrocola, F; Minois, N; Knittelfelder, O; Sica, V; Franz, J; Carmona-Gutierrez, D; Kroemer, G; Madeo, F

    2015-01-01

    Autophagy is a cellular recycling program that retards ageing by efficiently eliminating damaged and potentially harmful organelles and intracellular protein aggregates. Here, we show that the abundance of phosphatidylethanolamine (PE) positively regulates autophagy. Reduction of intracellular PE levels by knocking out either of the two yeast phosphatidylserine decarboxylases (PSD) accelerated chronological ageing-associated production of reactive oxygen species and death. Conversely, the artificial increase of intracellular PE levels, by provision of its precursor ethanolamine or by overexpression of the PE-generating enzyme Psd1, significantly increased autophagic flux, both in yeast and in mammalian cell culture. Importantly administration of ethanolamine was sufficient to extend the lifespan of yeast (Saccharomyces cerevisiae), mammalian cells (U2OS, H4) and flies (Drosophila melanogaster). We thus postulate that the availability of PE may constitute a bottleneck for functional autophagy and that organismal life or healthspan could be positively influenced by the consumption of ethanolamine-rich food. PMID:25571976

  7. Molecular topography of the secondary constriction region (qh) of human chromosome 9 with an unusual euchromatic band

    SciTech Connect

    Verma, R.S.; Luk, S.; Brennan, J.P.; Mathews, T.; Conte, R.A.; Macera, M.J. )

    1993-05-01

    Heterochromatin confined to pericentromeric (c) and secondary constriction (qh) regions plays a major role in morphological variation of chromosome 9, because of its size and affinity for pericentric inversion. Consequently, pairing at pachytene may lead to some disturbances between homologous chromosomes having such extreme variations and may result in abnormalities involving bands adjacent to the qh region. The authors encountered such a case, where a G-positive band has originated de nova, suggesting a maternal origin from the chromosome 9 that has had a complete pericentric inversion. In previously reported cases, the presence of an extra G-positive band within the 9qh region has been familial, and in the majority of those cases it was not associated with any clinical consequences. Therefore, this anomaly has been referred to as a [open quotes]rare[close quotes] variant. The qh region consists of a mixture of various tandemly repeated DNA sequences, and routine banding techniques have failed to characterize the origin of this extra genetic material. By the chromosome in situ suppression hybridization technique using whole chromosome paint, the probe annealed with the extra G-band, suggesting a euchromatic origin from chromosome 9, presumably band p12. By the fluorescence in situ hybridization technique using alpha- and beta-satellite probes, the dicentric nature was further revealed, supporting the concept of unequal crossing-over during maternal meiosis I, which could account for a duplication of the h region. The G-positive band most likely became genetically inert when it was sandwiched between two blocks of heterochromatin, resulting in a phenotypically normal child. Therefore, an earlier hypothesis, suggesting its origin from heterochromatin through so-called euchromatinization, is refuted here. If the proband's progeny inherit this chromosome, it shall be envisaged as a rare familial variant whose clinical consequences remain obscure. 52 refs., 3 figs.

  8. 16p11.2–p12.2 duplication syndrome; a genomic condition differentiated from euchromatic variation of 16p11.2

    PubMed Central

    Barber, John C K; Hall, Victoria; Maloney, Viv K; Huang, Shuwen; Roberts, Angharad M; Brady, Angela F; Foulds, Nicki; Bewes, Beverley; Volleth, Marianne; Liehr, Thomas; Mehnert, Karl; Bateman, Mark; White, Helen

    2013-01-01

    Chromosome 16 contains multiple copy number variations (CNVs) that predispose to genomic disorders. Here, we differentiate pathogenic duplications of 16p11.2–p12.2 from microscopically similar euchromatic variants of 16p11.2. Patient 1 was a girl of 18 with autism, moderate intellectual disability, behavioural difficulties, dysmorphic features and a 7.71-Mb (megabase pair) duplication (16:21 521 005–29 233 146). Patient 2 had a 7.81-Mb duplication (16:21 382 561–29 191 527), speech delay and obsessional behaviour as a boy and, as an adult, short stature, macrocephaly and mild dysmorphism. The duplications contain 65 coding genes of which Polo-like kinase 1 (PLK1) has the highest likelihood of being haploinsufficient and, by implication, a triplosensitive gene. An additional 1.11-Mb CNV of 10q11.21 in Patient 1 was a possible modifier containing the G-protein-regulated inducer of neurite growth 2 (GPRIN2) gene. In contrast, the euchromatic variants in Patients 3 and 4 were amplifications from a 945-kb region containing non-functional immunoglobulin heavy chain (IGHV), hect domain pseudogene (HERC2P4) and TP53-inducible target gene 3 (TP53TG3) loci in proximal 16p11.2 (16:31 953 353–32 898 635). Paralogous pyrosequencing gave a total copy number of 3–8 in controls and 8 to >10 in Patients 3 and 4. The 16p11.2–p12.2 duplication syndrome is a recurrent genomic disorder with a variable phenotype including developmental delay, dysmorphic features, mild to severe intellectual disability, autism, obsessive or stereotyped behaviour, short stature and anomalies of the hands and fingers. It is important to differentiate pathogenic 16p11.2–p12.2 duplications from harmless, microscopically similar euchromatic variants of proximal 16p11.2, especially at prenatal diagnosis. PMID:22828807

  9. [Regulation of thymocyte apoptosis and positive selection].

    PubMed

    Iwata, M

    1996-07-01

    Developing T cells undergo thymic selection at the CD4+CD8+ stage. Only less than 5% of CD4+CD8+ thymocytes are positively selected to survive and differentiate into mature single positive CD4 or CD8 T cells. Positive selection requires signaling through the T cell receptors (TCR) with assistance of CD4 or CD8 coreceptor and LFA-1, but its molecular mechanism is poorly understood. By using glucocorticoids, anti-apoptotic activity was detected in CD4+CD8+ thymocytes upon proper cross-linking of TCR/CD3 complex with CD4, CD8, or LFA-1, and was mimicked by a combination of a calcium ionophore and a protein kinase C activator. Isolated CD4+CD8+ thymocytes underwent differentiation and commitment to the CD4 T cell lineage by moderate and transient stimulation with this combination of the drugs. PMID:8741662

  10. Positive Emotion Regulation and Psychopathology: A Transdiagnostic Cultural Neuroscience Approach

    PubMed Central

    Hechtman, Lisa A.; Raila, Hannah; Chiao, Joan Y.; Gruber, June

    2013-01-01

    There is burgeoning interest in the study of positive emotion regulation and psychopathology. Given the significant public health costs and the tremendous variance in national prevalence rates associated with many disorders of positive emotion, it is critical to reach an understanding of how cultural factors, along with biological factors, mutually influence positive emotion regulation. Progress in this domain has been relatively unexplored, however, underscoring the need for an integrative review and empirical roadmap for investigating the cultural neuroscientific contributions to positive emotion disturbance for both affective and clinical science domains. The present paper thus provides a multidisciplinary, cultural neuroscience approach to better understand positive emotion regulation and psychopathology. We conclude with a future roadmap for researchers aimed at harnessing positive emotion and alleviating the burden of mental illness cross-culturally. PMID:24812583

  11. 102. Giullotine type gate (inclosed position to regulate furnace exhaust ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    102. Giullotine type gate (inclosed position to regulate furnace exhaust gases to stoves during heating cycle. - Sloss-Sheffield Steel & Iron, First Avenue North Viaduct at Thirty-second Street, Birmingham, Jefferson County, AL

  12. Wnt-regulated dynamics of positional information in zebrafish somitogenesis

    PubMed Central

    Bajard, Lola; Morelli, Luis G.; Ares, Saúl; Pécréaux, Jacques; Jülicher, Frank; Oates, Andrew C.

    2014-01-01

    How signaling gradients supply positional information in a field of moving cells is an unsolved question in patterning and morphogenesis. Here, we ask how a Wnt signaling gradient regulates the dynamics of a wavefront of cellular change in a flow of cells during somitogenesis. Using time-controlled perturbations of Wnt signaling in the zebrafish embryo, we changed segment length without altering the rate of somite formation or embryonic elongation. This result implies specific Wnt regulation of the wavefront velocity. The observed Wnt signaling gradient dynamics and timing of downstream events support a model for wavefront regulation in which cell flow plays a dominant role in transporting positional information. PMID:24595291

  13. Dynamics of positive emotion regulation: associations with youth depressive symptoms.

    PubMed

    Fussner, Lauren M; Luebbe, Aaron M; Bell, Debora J

    2015-04-01

    Depression is frequently considered a disorder of impaired affect regulation with deficits across both positive and negative affective systems. However, where deficits in emotion regulation occur in youth, specifically regarding regulation of positive emotions, is relatively unknown. The current study tested whether deficits in broad (felt and expressed) and specific (up-regulation and maintenance) positive emotion processes are associated with youth depressive symptoms. Adolescents (n = 134; 65 girls) in grades 7 to 9 completed a self-report measure of depressive symptoms prior to participating in two parent-child interactions tasks, a rewarding trivia task and a problem-solving conflict task. During the interaction tasks, adolescent's overall self-reported experience and observed expression of positive affect (PA) was examined. Following the reward task, youth's ability to up-regulate PA (PA response) and maintain PA while buffering against NA (PA persistence) was explored observationally. Results suggested that reduced experience and expression of PA was associated with depression symptoms, but only in a context that elicited negative emotions. No association was found between PA response and depression symptoms; however, shorter PA persistence was associated with elevated depressive symptoms. Youth higher in depressive symptoms appear able to respond similarly to rewarding events, but fail to maintain PA and ward off NA when transitioning from a positive to negative task. PMID:25070360

  14. An Integrative Theory-Driven Positive Emotion Regulation Intervention

    PubMed Central

    Weytens, Fanny; Luminet, Olivier; Verhofstadt, Lesley L.; Mikolajczak, Moïra

    2014-01-01

    Over the past fifteen years, positive psychology research has validated a set of happiness enhancing techniques. These techniques are relatively simple exercises that allow happiness seekers to mimic thoughts and behavior of naturally happy people, in order to increase their level of well-being. Because research has shown that the joint use of these exercises increases their effects, practitioners who want to help happiness seekers need validated interventions that combine several of these techniques. To meet this need, we have developed and tested an integrative intervention (Positive Emotion Regulation program – PER program) incorporating a number of validated techniques structured around a theoretical model: the Process Model of Positive Emotion Regulation. To test the effectiveness of this program and to identify its added value relative to existing interventions, 113 undergraduate students were randomly assigned to a 6-week positive emotion regulation pilot program, a loving-kindness meditation training program, or a wait-list control group. Results indicate that fewer participants dropped out from the PER program than from the Loving-Kindness Meditation training. Furthermore, subjects in the PER group showed a significant increase in subjective well-being and life satisfaction and a significant decrease in depression and physical symptoms when compared to controls. Our results suggest that the Process Model of Positive Emotion Regulation can be an effective option to organize and deliver positive integrative interventions. PMID:24759870

  15. Automatic emotion regulation after social exclusion: tuning to positivity.

    PubMed

    DeWall, C Nathan; Twenge, Jean M; Koole, Sander L; Baumeister, Roy F; Marquez, Allissa; Reid, Mark W

    2011-06-01

    Nine experiments tested competing hypotheses regarding nonconscious affective responses to acute social exclusion and how such responses may relate to positive mental health. The results strongly and consistently indicated that acute social exclusion increased nonconscious positive affect. Compared to nonexcluded participants, excluded participants recalled more positive memories from childhood than did accepted participants (Experiment 1), gave greater weight to positive emotion in their judgments of word similarity (Experiments 2 and 3), and completed more ambiguous word stems with happy words (Experiments 4a and 4b). This process was apparently automatic, as participants asked to imagine exclusion overestimated explicit distress and underestimated implicit positivity (Experiment 3). Four final experiments showed that this automatic emotion regulation process was found among participants low (but not high) in depressive symptoms (Experiments 5 and 6) and among participants high (but not low) in self-esteem (Experiments 7 and 8). These findings suggest that acute exclusion sets in motion an automatic emotion regulation process in which positive emotions become highly accessible, which relates to positive mental health. PMID:21668113

  16. RCAN 1 and 3 proteins regulate thymic positive selection.

    PubMed

    Serrano-Candelas, Eva; Alemán-Muench, Germán; Solé-Sánchez, Sònia; Aubareda, Anna; Martínez-Høyer, Sergio; Adán, Jaume; Aranguren-Ibáñez, Álvaro; Pritchard, Melanie A; Soldevila, Gloria; Pérez-Riba, Mercè

    2015-05-01

    Cooperation between calcineurin (CN)-NFATc and RAF-MEK-ERK signaling pathways is essential in thymocyte positive selection. It is known that the Regulators of Calcineurin (RCAN) proteins can act either facilitating or suppressing CN-dependent signaling events. Here, we show that RCAN genes are expressed in lymphoid tissues, and address the role of RCAN proteins in T cell development. Overexpression of human RCAN3 and RCAN1 can modulate T cell development by increasing positive selection-related surface markers, as well as the "Erk(hi) competence state" in double positive thymocytes, a characteristic molecular signature of positive selection, without affecting CN activity. We also found that RCAN1/3 interact with RAF kinases and CN in a non-exclusive manner. Our data suggests that the balance of RCAN interactions with CN and/or RAF kinases may influence T cell positive selection. PMID:25783055

  17. Regulation of positive and negative emotion: effects of sociocultural context

    PubMed Central

    Snyder, Sara A.; Heller, S. Megan; Lumian, Daniel S.; McRae, Kateri

    2013-01-01

    Previous research has demonstrated that the use of emotion regulation strategies can vary by sociocultural context. In a previous study, we reported changes in the use of two different emotion regulation strategies at an annual alternative cultural event, Burning Man (McRae et al., 2011). In this sociocultural context, as compared to typically at home, participants reported less use of expressive suppression (a strategy generally associated with maladaptive outcomes), and greater use of cognitive reappraisal (a strategy generally associated with adaptive outcomes). What remained unclear was whether these changes in self-reported emotion regulation strategy use were characterized by changes in the regulation of positive emotion, negative emotion, or both. We addressed this issue in the current study by asking Burning Man participants separate questions about positive and negative emotion. Using multiple datasets, we replicated our previous findings, and found that the decreased use of suppression is primarily driven by reports of decreased suppression of positive emotion at Burning Man. By contrast, the increased use of reappraisal is not characterized by differential reappraisal of positive and negative emotion at Burning Man. Moreover, we observed novel individual differences in the magnitude of these effects. The contextual changes in self-reported suppression that we observe are strongest for men and younger participants. For those who had previously attended Burning Man, we observed lower levels of self-reported suppression in both sociocultural contexts: Burning Man and typically at home. These findings have implications for understanding the ways in which certain sociocultural contexts may decrease suppression, and possibly minimize its associated maladaptive effects. PMID:23840191

  18. Neuropilins are positive regulators of Hedgehog signal transduction.

    PubMed

    Hillman, R Tyler; Feng, Brian Y; Ni, Jun; Woo, Wei-Meng; Milenkovic, Ljiljana; Hayden Gephart, Melanie G; Teruel, Mary N; Oro, Anthony E; Chen, James K; Scott, Matthew P

    2011-11-15

    The Hedgehog (Hh) pathway is essential for vertebrate embryogenesis, and excessive Hh target gene activation can cause cancer in humans. Here we show that Neuropilin 1 (Nrp1) and Nrp2, transmembrane proteins with roles in axon guidance and vascular endothelial growth factor (VEGF) signaling, are important positive regulators of Hh signal transduction. Nrps are expressed at times and locations of active Hh signal transduction during mouse development. Using cell lines lacking key Hh pathway components, we show that Nrps mediate Hh transduction between activated Smoothened (Smo) protein and the negative regulator Suppressor of Fused (SuFu). Nrp1 transcription is induced by Hh signaling, and Nrp1 overexpression increases maximal Hh target gene activation, indicating the existence of a positive feedback circuit. The regulation of Hh signal transduction by Nrps is conserved between mammals and bony fish, as we show that morpholinos targeting the Nrp zebrafish ortholog nrp1a produce a specific and highly penetrant Hh pathway loss-of-function phenotype. These findings enhance our knowledge of Hh pathway regulation and provide evidence for a conserved nexus between Nrps and this important developmental signaling system. PMID:22051878

  19. Compassion-based emotion regulation up-regulates experienced positive affect and associated neural networks.

    PubMed

    Engen, Haakon G; Singer, Tania

    2015-09-01

    Emotion regulation research has primarily focused on techniques that attenuate or modulate the impact of emotional stimuli. Recent evidence suggests that this mode regulation can be problematic in the context of regulation of emotion elicited by the suffering of others, resulting in reduced emotional connectedness. Here, we investigated the effects of an alternative emotion regulation technique based on the up-regulation of positive affect via Compassion-meditation on experiential and neural affective responses to depictions of individuals in distress, and compared these with the established emotion regulation strategy of Reappraisal. Using fMRI, we scanned 15 expert practitioners of Compassion-meditation either passively viewing, or using Compassion-meditation or Reappraisal to modulate their emotional reactions to film clips depicting people in distress. Both strategies effectively, but differentially regulated experienced affect, with Compassion primarily increasing positive and Reappraisal primarily decreasing negative affect. Imaging results showed that Compassion, relative to both passive-viewing and Reappraisal increased activation in regions involved in affiliation, positive affect and reward processing including ventral striatum and medial orbitfrontal cortex. This network was shown to be active prior to stimulus presentation, suggesting that the regulatory mechanism of Compassion is the stimulus-independent endogenous generation of positive affect. PMID:25698699

  20. Quorum sensing positively regulates flagellar motility in pathogenic Vibrio harveyi.

    PubMed

    Yang, Qian; Defoirdt, Tom

    2015-04-01

    Vibrios belonging to the Harveyi clade are among the major pathogens of aquatic organisms. Quorum sensing (QS) is essential for virulence of V. harveyi towards different hosts. However, most virulence factors reported to be controlled by QS to date are negatively regulated by QS, therefore suggesting that their impact on virulence is limited. In this study, we report that QS positively regulates flagellar motility. We found that autoinducer synthase mutants showed significantly lower swimming motility than the wild type, and the swimming motility could be restored by adding synthetic signal molecules. Further, motility of a luxO mutant with inactive QS (LuxO D47E) was significantly lower than that of the wild type and of a luxO mutant with constitutively maximal QS activity (LuxO D47A). Furthermore, we found that the expression of flagellar genes (both early, middle and late genes) was significantly lower in the luxO mutant with inactive QS when compared with wild type and the luxO mutant with maximal QS activity. Motility assays and gene expression also revealed the involvement of the quorum-sensing master regulator LuxR in the QS regulation of motility. Finally, the motility inhibitor phenamil significantly decreased the virulence of V. harveyi towards gnotobiotic brine shrimp larvae. PMID:24528485

  1. BORC, a Multisubunit Complex that Regulates Lysosome Positioning

    PubMed Central

    Pu, Jing; Schindler, Christina; Jia, Rui; Jarnik, Michal; Backlund, Peter; Bonifacino, Juan S.

    2016-01-01

    SUMMARY The positioning of lysosomes within the cytoplasm is emerging as a critical determinant of many lysosomal functions. Here we report the identification of a multi-subunit complex named BORC that regulates lysosome positioning. BORC comprises eight subunits, some of which are shared with the BLOC-1 complex involved in the biogenesis of lysosome-related organelles, and the others of which are products of previously uncharacterized open reading frames. BORC associates peripherally with the lysosomal membrane, where it functions to recruit the small GTPase Arl8. This initiates a chain of interactions that promotes the Kinesin-1-dependent movement of lysosomes toward the plus ends of microtubules in the peripheral cytoplasm. Interference with BORC or other components of this pathway results in collapse of the lysosomal population into the pericentriolar region. In turn, this causes reduced cell spreading and migration, highlighting the importance of BORC-dependent centrifugal transport for non-degradative functions of lysosomes. PMID:25898167

  2. Positive and negative regulators of the metallothionein gene (review).

    PubMed

    Takahashi, Shinichiro

    2015-07-01

    Metallothioneins (MTs) are metal-binding proteins involved in diverse processes, including metal homeostasis and detoxification, the oxidative stress response and cell proliferation. Aberrant expression and silencing of these genes are important in a number of diseases. Several positive regulators of MT genes, including metal-responsive element-binding transcription factor (MTF)-1 and upstream stimulatory factor (USF)-1, have been identified and mechanisms of induction have been well described. However, the negative regulators of MT genes remain to be elucidated. Previous studies from the group of the present review have revealed that the hematopoietic master transcription factor, PU.1, directly represses the expression levels of MT genes through its epigenetic activities, and upregulation of MT results in the potent inhibition of myeloid differentiation. The present review focuses on PU.1 and several other negative regulators of this gene, including PZ120, DNA methyltransferase 3a with Mbd3 and Brg1 complex, CCAAT enhancer binding protein α and Ku protein, and describes the suppression of the MT genes through these transcription factors. PMID:25760317

  3. Werner syndrome protein positively regulates XRCC4-like factor transcription

    PubMed Central

    LIU, DONGYUN; DENG, XIAOLI; YUAN, CHONGZHEN; CHEN, LIN; CONG, YUSHENG; XU, XINGZHI

    2014-01-01

    XRCC4-like factor (XLF) is involved in non-homologous end joining-mediated repair of DNA double-strand breaks (DSBs). Mutations in the WRN gene results in the development of Werner syndrome (WS), a rare autosomal recessive disorder characterized by premature ageing and genome instability. In the present study, it was identified that XLF protein levels were lower in WRN-deficient fibroblasts, compared with normal fibroblasts. Depletion of WRN in HeLa cells led to a decrease of XLF mRNA and its promoter activity. Chromatin immunoprecipitation assays demonstrated that WRN was associated with the XLF promoter. Depletion of XLF in normal human fibroblasts increased the percentage of β-galactosidase (β-gal) staining-positive cells, indicating acceleration in cellular senescence. Taken together, the results suggest that XLF is a transcriptional target of WRN and may be involved in the regulation of cellular senescence. PMID:24626809

  4. HMGCR positively regulated the growth and migration of glioblastoma cells.

    PubMed

    Qiu, Zhihua; Yuan, Wen; Chen, Tao; Zhou, Chenzhi; Liu, Chao; Huang, Yongkai; Han, Deqing; Huang, Qinghui

    2016-01-15

    The metabolic program of cancer cells is significant different from the normal cells, which makes it possible to develop novel strategies targeting cancer cells. Mevalonate pathway and its rate-limiting enzyme HMG-CoA reductase (HMGCR) have shown important roles in the progression of several cancer types. However, their roles in glioblastoma cells remain unknown. In this study, up-regulation of HMGCR in the clinical glioblastoma samples was observed. Forced expression of HMGCR promoted the growth and migration of U251 and U373 cells, while knocking down the expression of HMGCR inhibited the growth, migration and metastasis of glioblastoma cells. Molecular mechanism studies revealed that HMGCR positively regulated the expression of TAZ, an important mediator of Hippo pathway, and the downstream target gene connective tissue growth factor (CTGF), suggesting HMGCR might activate Hippo pathway in glioblastoma cells. Taken together, our study demonstrated the oncogenic roles of HMGCR in glioblastoma cells and HMGCR might be a promising therapeutic target. PMID:26432005

  5. LATS2 Positively Regulates Polycomb Repressive Complex 2

    PubMed Central

    Torigata, Kosuke; Daisuke, Okuzaki; Mukai, Satomi; Hatanaka, Akira; Ohka, Fumiharu; Motooka, Daisuke; Nakamura, Shota; Ohkawa, Yasuyuki; Yabuta, Norikazu; Kondo, Yutaka; Nojima, Hiroshi

    2016-01-01

    LATS2, a pivotal Ser/Thr kinase of the Hippo pathway, plays important roles in many biological processes. LATS2 also function in Hippo-independent pathway, including mitosis, DNA damage response and epithelial to mesenchymal transition. However, the physiological relevance and molecular basis of these LATS2 functions remain obscure. To understand novel functions of LATS2, we constructed a LATS2 knockout HeLa-S3 cell line using TAL-effector nuclease (TALEN). Integrated omics profiling of this cell line revealed that LATS2 knockout caused genome-wide downregulation of Polycomb repressive complex 2 (PRC2) and H3K27me3. Cell-cycle analysis revealed that downregulation of PRC2 was not due to cell cycle aberrations caused by LATS2 knockout. Not LATS1, a homolog of LATS2, but LATS2 bound PRC2 on chromatin and phosphorylated it. LATS2 positively regulates histone methyltransferase activity of PRC2 and their expression at both the mRNA and protein levels. Our findings reveal a novel signal upstream of PRC2, and provide insight into the crucial role of LATS2 in coordinating the epigenome through regulation of PRC2. PMID:27434182

  6. LATS2 Positively Regulates Polycomb Repressive Complex 2.

    PubMed

    Torigata, Kosuke; Daisuke, Okuzaki; Mukai, Satomi; Hatanaka, Akira; Ohka, Fumiharu; Motooka, Daisuke; Nakamura, Shota; Ohkawa, Yasuyuki; Yabuta, Norikazu; Kondo, Yutaka; Nojima, Hiroshi

    2016-01-01

    LATS2, a pivotal Ser/Thr kinase of the Hippo pathway, plays important roles in many biological processes. LATS2 also function in Hippo-independent pathway, including mitosis, DNA damage response and epithelial to mesenchymal transition. However, the physiological relevance and molecular basis of these LATS2 functions remain obscure. To understand novel functions of LATS2, we constructed a LATS2 knockout HeLa-S3 cell line using TAL-effector nuclease (TALEN). Integrated omics profiling of this cell line revealed that LATS2 knockout caused genome-wide downregulation of Polycomb repressive complex 2 (PRC2) and H3K27me3. Cell-cycle analysis revealed that downregulation of PRC2 was not due to cell cycle aberrations caused by LATS2 knockout. Not LATS1, a homolog of LATS2, but LATS2 bound PRC2 on chromatin and phosphorylated it. LATS2 positively regulates histone methyltransferase activity of PRC2 and their expression at both the mRNA and protein levels. Our findings reveal a novel signal upstream of PRC2, and provide insight into the crucial role of LATS2 in coordinating the epigenome through regulation of PRC2. PMID:27434182

  7. FLC-mediated flowering repression is positively regulated by sumoylation

    PubMed Central

    Seo, Hak Soo

    2014-01-01

    Flowering locus C (FLC), a floral repressor, is a critical factor for the transition from the vegetative to the reproductive phase. Here, the mechanisms regulating the activity and stability of the FLC protein were investigated. Bimolecular fluorescence complementation and in vitro pull-down analyses showed that FLC interacts with the E3 small ubiquitin-like modifier (SUMO) ligase AtSIZ1, suggesting that AtSIZ1 is an E3 SUMO ligase for FLC. In vitro sumoylation assays showed that FLC is modified by SUMO in the presence of SUMO-activating enzyme E1 and conjugating enzyme E2, but its sumoylation is inhibited by AtSIZ1. In transgenic plants, inducible AtSIZ1 overexpression led to an increase in the concentration of FLC and delayed the post-translational decay of FLC, indicating that AtSIZ1 stabilizes FLC through direct binding. Also, the flowering time in mutant FLC (K154R, a mutation of the sumoylation site)-overexpressing plants was comparable with that in the wild type, whereas flowering was considerably delayed in FLC-overexpressing plants, supporting the notion that sumoylation is an important mechanism for FLC function. The data indicate that the sumoylation of FLC is critical for its role in the control of flowering time and that AtSIZ1 positively regulates FLC-mediated floral suppression. PMID:24218331

  8. Genome-wide analysis of tandem repeats in Tribolium castaneum genome reveals abundant and highly dynamic tandem repeat families with satellite DNA features in euchromatic chromosomal arms

    PubMed Central

    Pavlek, Martina; Gelfand, Yevgeniy; Plohl, Miroslav; Meštrović, Nevenka

    2015-01-01

    Although satellite DNAs are well-explored components of heterochromatin and centromeres, little is known about emergence, dispersal and possible impact of comparably structured tandem repeats (TRs) on the genome-wide scale. Our bioinformatics analysis of assembled Tribolium castaneum genome disclosed significant contribution of TRs in euchromatic chromosomal arms and clear predominance of satellite DNA-typical 170 bp monomers in arrays of ≥5 repeats. By applying different experimental approaches, we revealed that the nine most prominent TR families Cast1–Cast9 extracted from the assembly comprise ∼4.3% of the entire genome and reside almost exclusively in euchromatic regions. Among them, seven families that build ∼3.9% of the genome are based on ∼170 and ∼340 bp long monomers. Results of phylogenetic analyses of 2500 monomers originating from these families show high-sequence dynamics, evident by extensive exchanges between arrays on non-homologous chromosomes. In addition, our analysis shows that concerted evolution acts more efficiently on longer than on shorter arrays. Efficient genome-wide distribution of nine TR families implies the role of transposition only in expansion of the most dispersed family, and involvement of other mechanisms is anticipated. Despite similarities in sequence features, FISH experiments indicate high-level compartmentalization of centromeric and euchromatic tandem repeats. PMID:26428853

  9. Regulating the High: Cognitive and Neural Processes Underlying Positive Emotion Regulation in Bipolar I Disorder

    PubMed Central

    Park, Jiyoung; Ayduk, Özlem; O'Donnell, Lisa; Chun, Jinsoo; Gruber, June; Kamali, Masoud; McInnis, Melvin; Deldin, Patricia; Kross, Ethan

    2015-01-01

    Although it is well established that Bipolar Disorder (BD) is characterized by excessive positive emotionality, the cognitive and neural processes that underlie such responses are unclear. We addressed this issue by examining the role that an emotion regulatory process called self-distancing plays in two potentially different BD phenotypes—BD with vs. without a history of psychosis—and healthy individuals. Participants reflected on a positive autobiographical memory and then rated their level of spontaneous self-distancing. Neurophysiological activity was continuously monitored using electroencephalogram. As predicted, participants with BD who have a history of psychosis spontaneously self-distanced less and displayed greater neurophysiological signs of positive emotional reactivity compared to the other two groups. These findings shed light on the cognitive and neural mechanisms underlying excessive positive emotionality in BD. They also suggest that individuals with BD who have a history of psychosis may represent a distinct clinical phenotype characterized by dysfunctional emotion regulation. PMID:26719819

  10. Phosphatidylserine directly and positively regulates fusion of myoblasts into myotubes.

    PubMed

    Jeong, Jaemin; Conboy, Irina M

    2011-10-14

    Cell membrane consists of various lipids such as phosphatidylserine (PS), phosphatidylcholine (PC), and phosphatidylethanolamine (PE). Among them, PS is a molecular marker of apoptosis, because it is located to the inner leaflet of plasma membrane generally but it is moved to the outer leaflet during programmed cell death. The process of apoptosis has been implicated in the fusion of muscle progenitor cells, myoblasts, into myotubes. However, it remained unclear whether PS regulates muscle cell differentiation directly. In this paper, localization of PS to the outer leaflet of plasma membrane in proliferating primary myoblasts and during fusion of these myoblasts into myotubes is validated using Annexin V. Moreover, we show the presence of PS clusters at the cell-cell contact points, suggesting the importance of membrane ruffling and PS exposure for the myogenic cell fusion. Confirming this conclusion, experimentally constructed PS, but not PC liposomes dramatically enhance the formation of myotubes from myoblasts, thus demonstrating a direct positive effect of PS on the muscle cell fusion. In contrast, myoblasts exposed to PC liposomes produce long myotubes with low numbers of myonuclei. Moreover, pharmacological masking of PS on the myoblast surface inhibits fusion of these cells into myotubes in a dose-dependent manner. PMID:21910971

  11. Interleukin-32 Positively Regulates Radiation-Induced Vascular Inflammation

    SciTech Connect

    Kobayashi, Hanako; Yazlovitskaya, Eugenia M.; Lin, P. Charles

    2009-08-01

    Purpose: To study the role of interleukin-32 (IL-32), a novel protein only detected in human tissues, in ionizing radiation (IR)-induced vascular inflammation. Methods and Materials: Irradiated (0-6 Gy) human umbilical vein endothelial cells treated with or without various agents-a cytosolic phospholipase A2 (cPLA2) inhibitor, a cyclooxygenase-2 (Cox-2) inhibitor, or lysophosphatidylcholines (LPCs)-were used to assess IL-32 expression by Northern blot analysis and quantitative reverse transcriptase-polymerase chain reaction. Expression of cell adhesion molecules and leukocyte adhesion to endothelial cells using human acute monocytic leukemia cell line (THP-1) cells was also analyzed. Results: Ionizing radiation dramatically increased IL-32 expression in vascular endothelial cells through multiple pathways. Ionizing radiation induced IL-32 expression through nuclear factor {kappa}B activation, through induction of cPLA2 and LPC, as well as induction of Cox-2 and subsequent conversion of arachidonic acid to prostacyclin. Conversely, blocking nuclear factor {kappa}B, cPLA2, and Cox-2 activity impaired IR-induced IL-32 expression. Importantly, IL-32 significantly enhanced IR-induced expression of vascular cell adhesion molecules and leukocyte adhesion on endothelial cells. Conclusion: This study identifies IL-32 as a positive regulator in IR-induced vascular inflammation, and neutralization of IL-32 may be beneficial in protecting from IR-induced inflammation.

  12. Cathelicidins positively regulate pancreatic β-cell functions.

    PubMed

    Sun, Jia; Xu, Meng; Ortsäter, Henrik; Lundeberg, Erik; Juntti-Berggren, Lisa; Chen, Yong Q; Haeggström, Jesper Z; Gudmundsson, Gudmundur H; Diana, Julien; Agerberth, Birgitta

    2016-02-01

    Cathelicidins are pleiotropic antimicrobial peptides largely described for innate antimicrobial defenses and, more recently, immunomodulation. They are shown to modulate a variety of immune or nonimmune host cell responses. However, how cathelicidins are expressed by β cells and modulate β-cell functions under steady-state or proinflammatory conditions are unknown. We find that cathelicidin-related antimicrobial peptide (CRAMP) is constitutively expressed by rat insulinoma β-cell clone INS-1 832/13. CRAMP expression is inducible by butyrate or phenylbutyric acid and its secretion triggered upon inflammatory challenges by IL-1β or LPS. CRAMP promotes β-cell survival in vitro via the epidermal growth factor receptor (EGFR) and by modulating expression of antiapoptotic Bcl-2 family proteins: p-Bad, Bcl-2, and Bcl-xL. Also via EGFR, CRAMP stimulates glucose-stimulated insulin secretion ex vivo by rat islets. A similar effect is observed in diabetes-prone nonobese diabetic (NOD) mice. Additional investigation under inflammatory conditions reveals that CRAMP modulates inflammatory responses and β-cell apoptosis, as measured by prostaglandin E2 production, cyclooxygenases (COXs), and caspase activation. Finally, CRAMP-deficient cnlp(-/-) mice exhibit defective insulin secretion, and administration of CRAMP to prediabetic NOD mice improves blood glucose clearance upon glucose challenge. Our finding suggests that cathelicidins positively regulate β-cell functions and may be potentially used for intervening β-cell dysfunction-associated diseases. PMID:26527065

  13. Ccndbp1 is a new positive regulator of skeletal myogenesis.

    PubMed

    Huang, Yan; Chen, Bohong; Ye, Miaoman; Liang, Puping; Zhangfang, Yingnan; Huang, Junjiu; Liu, Mingyao; Songyang, Zhou; Ma, Wenbin

    2016-07-15

    Skeletal myogenesis is a multistep process in which basic helix-loop-helix (bHLH) transcription factors, such as MyoD (also known as MyoD1), bind to E-boxes and activate downstream genes. Ccndbp1 is a HLH protein that lacks a DNA-binding region, and its function in skeletal myogenesis is currently unknown. We generated Ccndbp1-null mice by using CRISPR-Cas9. Notably, in Ccndbp1-null mice, the cross sectional area of the skeletal tibialis anterior muscle was smaller, and muscle regeneration ability and grip strength were impaired, compared with those of wild type. This phenotype resembled that of myofiber hypotrophy in some human myopathies or amyoplasia. Ccndbp1 expression was upregulated during C2C12 myogenesis. Ccndbp1 overexpression promoted myogenesis, whereas knockdown of Ccndbp1 inhibited myogenic differentiation. Co-transfection of Ccndbp1 with MyoD and/or E47 (encoded by TCF3) significantly enhanced E-box-dependent transcription. Furthermore, Ccndbp1 physically associated with MyoD but not E47. These data suggest that Ccndbp1 regulates muscle differentiation by interacting with MyoD and enhancing its binding to target genes. Our study newly identifies Ccndbp1 as a positive modulator of skeletal myogenic differentiation in vivo and in vitro, providing new insights in order to decipher the complex network involved in skeletal myogenic development and related diseases. PMID:27235421

  14. Phosphatidylserine directly and positively regulates fusion of myoblasts into myotubes

    SciTech Connect

    Jeong, Jaemin; Conboy, Irina M.

    2011-10-14

    Highlights: {yields} PS broadly and persistently trans-locates to the outer leaflet of plasma membrane during myoblast fusion into myotubes. {yields} Robust myotubes are formed when PS liposomes are added exogenously. {yields} PS increases the width of de novo myotubes and the numbers of myonuclei, but not the myotube length. {yields} Annexin V or PS antibody inhibits myotube formation by masking exposed PS. -- Abstract: Cell membrane consists of various lipids such as phosphatidylserine (PS), phosphatidylcholine (PC), and phosphatidylethanolamine (PE). Among them, PS is a molecular marker of apoptosis, because it is located to the inner leaflet of plasma membrane generally but it is moved to the outer leaflet during programmed cell death. The process of apoptosis has been implicated in the fusion of muscle progenitor cells, myoblasts, into myotubes. However, it remained unclear whether PS regulates muscle cell differentiation directly. In this paper, localization of PS to the outer leaflet of plasma membrane in proliferating primary myoblasts and during fusion of these myoblasts into myotubes is validated using Annexin V. Moreover, we show the presence of PS clusters at the cell-cell contact points, suggesting the importance of membrane ruffling and PS exposure for the myogenic cell fusion. Confirming this conclusion, experimentally constructed PS, but not PC liposomes dramatically enhance the formation of myotubes from myoblasts, thus demonstrating a direct positive effect of PS on the muscle cell fusion. In contrast, myoblasts exposed to PC liposomes produce long myotubes with low numbers of myonuclei. Moreover, pharmacological masking of PS on the myoblast surface inhibits fusion of these cells into myotubes in a dose-dependent manner.

  15. Spontaneous Emotion Regulation to Positive and Negative Stimuli

    ERIC Educational Resources Information Center

    Volokhov, Rachael N.; Demaree, Heath A.

    2010-01-01

    The ability to regulate one's emotions is an integral part of human social behavior. One antecedent emotion regulation strategy, known as reappraisal, is characterized by cognitively evaluating an emotional stimulus to alter its emotional impact and one response-focused strategy, suppression, is aimed at reducing behavioral output. People are…

  16. Certification Regulations for Teachers and Qualifications for Administrative, Supervisory, and Related Instructional Positions.

    ERIC Educational Resources Information Center

    Virginia State Dept. of Education, Richmond.

    The regulations governing the certification of teachers, qualifications for administrative, supervisory and related instructional positions, and administrative procedures for the state of Virginia are given. (JD)

  17. Tyrosine 370 phosphorylation of ATM positively regulates DNA damage response

    PubMed Central

    Lee, Hong-Jen; Lan, Li; Peng, Guang; Chang, Wei-Chao; Hsu, Ming-Chuan; Wang, Ying-Nai; Cheng, Chien-Chia; Wei, Leizhen; Nakajima, Satoshi; Chang, Shih-Shin; Liao, Hsin-Wei; Chen, Chung-Hsuan; Lavin, Martin; Ang, K Kian; Lin, Shiaw-Yih; Hung, Mien-Chie

    2015-01-01

    Ataxia telangiectasia mutated (ATM) mediates DNA damage response by controling irradiation-induced foci formation, cell cycle checkpoint, and apoptosis. However, how upstream signaling regulates ATM is not completely understood. Here, we show that upon irradiation stimulation, ATM associates with and is phosphorylated by epidermal growth factor receptor (EGFR) at Tyr370 (Y370) at the site of DNA double-strand breaks. Depletion of endogenous EGFR impairs ATM-mediated foci formation, homologous recombination, and DNA repair. Moreover, pretreatment with an EGFR kinase inhibitor, gefitinib, blocks EGFR and ATM association, hinders CHK2 activation and subsequent foci formation, and increases radiosensitivity. Thus, we reveal a critical mechanism by which EGFR directly regulates ATM activation in DNA damage response, and our results suggest that the status of ATM Y370 phosphorylation has the potential to serve as a biomarker to stratify patients for either radiotherapy alone or in combination with EGFR inhibition. PMID:25601159

  18. YY1 positively regulates human UBIAD1 expression

    SciTech Connect

    Funahashi, Nobuaki; Hirota, Yoshihisa; Nakagawa, Kimie; Sawada, Natumi; Watanabe, Masato; Suhara, Yoshitomo; Okano, Toshio

    2015-05-01

    Vitamin K is involved in bone formation and blood coagulation. Natural vitamin K compounds are composed of the plant form phylloquinone (vitamin K{sub 1}) and a series of bacterial menaquionones (MK-n; vitamin K{sub 2}). Menadione (vitamin K{sub 3}) is an artificial vitamin K compound. MK-4 contains 4-isoprenyl as a side group in the 2-methyl-1,4-naphthoquinone common structure and has various bioactivities. UbiA prenyltransferase domain containing 1 (UBIAD1 or TERE1) is the menaquinone-4 biosynthetic enzyme. UBIAD1 transcript expression significantly decreases in patients with prostate carcinoma and overexpressing UBIAD1 inhibits proliferation of a tumour cell line. UBIAD1 mRNA expression is ubiquitous in mouse tissues, and higher UBIAD1 mRNA expression levels are detected in the brain, heart, kidneys and pancreas. Several functions of UBIAD1 have been reported; however, regulation of the human UBIAD1 gene has not been elucidated. Here we report cloning and characterisation of the human UBIAD1 promoter. A 5′ rapid amplification of cDNA ends analysis revealed that the main transcriptional start site was 306 nucleotides upstream of the translation initiation codon. Deletion and mutation analyses revealed the functional importance of the YY1 consensus motif. Electrophoretic gel mobility shift and chromatin immunoprecipitation assays demonstrated that YY1 binds the UBIAD1 promoter in vitro and in vivo. In addition, YY1 small interfering RNA decreased endogenous UBIAD1 mRNA expression and UBIAD1 conversion activity. These results suggest that YY1 up-regulates UBIAD1 expression and UBIAD1 conversion activity through the UBIAD1 promoter. - Highlights: • We cloned the human UBIAD1 promoter. • The functional importance of the YY1 motif was identified in the UBIAD1 promoter. • YY1 binds the UBIAD1 promoter in vitro and in vivo. • Knockdown of YY1 significantly decreased UBIAD1 expression. • YY1 up-regulates UBIAD1 conversion activity through the UBIAD1

  19. Ultrasensitive gene regulation by positive feedback loops in nucleosome modification.

    PubMed

    Sneppen, Kim; Micheelsen, Mille A; Dodd, Ian B

    2008-01-01

    Eukaryotic transcription involves the synergistic interaction of many different proteins. However, the question remains how eukaryotic promoters achieve ultrasensitive or threshold responses to changes in the concentration or activity of a single transcription factor (TF). We show theoretically that by recruiting a histone-modifying enzyme, a TF binding non-cooperatively to a single site can change the balance between opposing positive feedback loops in histone modification to produce a large change in gene expression in response to a small change in concentration of the TF. This mechanism can also generate bistable promoter responses, allowing a gene to be on in some cells and off in others, despite the cells being in identical conditions. In addition, the system provides a simple means by which the activities of many TFs could be integrated at a promoter. PMID:18414483

  20. Afzelin positively regulates melanogenesis through the p38 MAPK pathway.

    PubMed

    Jung, Eunsun; Kim, Jin Hee; Kim, Mi Ok; Jang, Sunghee; Kang, Mingyeong; Oh, Sae Woong; Nho, Youn Hwa; Kang, Seung Hyun; Kim, Min Hee; Park, See-Hyoung; Lee, Jongsung

    2016-07-25

    Melanogenesis refers to synthesis of the skin pigment melanin, which plays a critical role in the protection of skin against ultraviolet irradiation and oxidative stressors. We investigated the effects of afzelin on melanogenesis and its mechanisms of action in human epidermal melanocytes. In this study, we found that afzelin increased both melanin content and tyrosinase activity in a concentration-dependent manner. While the mRNA levels of microphthalmia-associated transcription factor (MITF), tyrosinase, and tyrosinase-related protein (TRP)-1 increased following afzelin treatment, the mRNA levels of TRP-2 were not affected by afzelin. Likewise, afzelin increased the protein levels of MITF, TRP-1, and tyrosinase but not TRP-2. Mechanistically, we found that afzelin regulated melanogenesis by upregulating MITF through phosphorylation of p38 mitogen-activated protein kinase (MAPK), independent of cyclic adenosine monophosphate (cAMP)-protein kinase A (PKA) signaling. Taken together, these findings indicate that the promotion of melanogenesis by afzelin occurs through increased MITF gene expression, which is mediated by activation of p38 MAPK, and suggest that afzelin may be useful as a protective agent against ultraviolet irradiation. PMID:27287415

  1. Longitudinal study of self-regulation, positive parenting, and adjustment problems among physically abused children

    PubMed Central

    Kim, Jungmeen; Haskett, Mary E.; Longo, Gregory S.; Nice, Rachel

    2012-01-01

    Objective Research using normative and high-risk samples indicates a significant link between problems with self-regulation and child maladjustment. Nevertheless, little is known about the processes that may modify the link between self-regulation and maladjustment. This longitudinal study examined the joint contributions of child self-regulation and positive parenting behaviors to the development of externalizing and internalizing symptomatology spanning from preschool to 1st grade. Methods Data were collected on a total of 95 physically abused children (58% boys); our longitudinal analyses involved 43 children at Time 1 (preschool), 63 children at Time 2 (kindergarten), and 54 children at Time 3 (1st grade). Children's self-regulation was measured by parent report, and their externalizing and internalizing symptomatology was evaluated by teachers. Parents completed self-report measures of positive parenting. Results Our structural equation modeling analyses revealed positive parenting as a protective factor that attenuated the concurrent association between low self-regulation and externalizing symptomatology among physically abused children. Our findings regarding longitudinal changes in children's externalizing symptomatology supported the differential susceptibility hypothesis: Physically abused children who were at greater risk due to low levels of self-regulation were more susceptible to the beneficial effects of positive parenting, compared to those with high levels of self-regulation. Conclusions Findings suggest that although physical abuse presents formidable challenges that interfere with the development of adaptive self-regulation, positive parenting behaviors may ameliorate the detrimental effects of maladaptive self-regulation on the development of externalizing symptomatology. In addition, the positive and negative effects of caregiving behaviors were more prominent among physically abused children at great risk due to low self-regulation. Practice

  2. Miro1 Regulates Activity-Driven Positioning of Mitochondria within Astrocytic Processes Apposed to Synapses to Regulate Intracellular Calcium Signaling.

    PubMed

    Stephen, Terri-Leigh; Higgs, Nathalie F; Sheehan, David F; Al Awabdh, Sana; López-Doménech, Guillermo; Arancibia-Carcamo, I Lorena; Kittler, Josef T

    2015-12-01

    It is fast emerging that maintaining mitochondrial function is important for regulating astrocyte function, although the specific mechanisms that govern astrocyte mitochondrial trafficking and positioning remain poorly understood. The mitochondrial Rho-GTPase 1 protein (Miro1) regulates mitochondrial trafficking and detachment from the microtubule transport network to control activity-dependent mitochondrial positioning in neurons. However, whether Miro proteins are important for regulating signaling-dependent mitochondrial dynamics in astrocytic processes remains unclear. Using live-cell confocal microscopy of rat organotypic hippocampal slices, we find that enhancing neuronal activity induces transient mitochondrial remodeling in astrocytes, with a concomitant, transient reduction in mitochondrial trafficking, mediated by elevations in intracellular Ca(2+). Stimulating neuronal activity also induced mitochondrial confinement within astrocytic processes in close proximity to synapses. Furthermore, we show that the Ca(2+)-sensing EF-hand domains of Miro1 are important for regulating mitochondrial trafficking in astrocytes and required for activity-driven mitochondrial confinement near synapses. Additionally, activity-dependent mitochondrial positioning by Miro1 reciprocally regulates the levels of intracellular Ca(2+) in astrocytic processes. Thus, the regulation of intracellular Ca(2+) signaling, dependent on Miro1-mediated mitochondrial positioning, could have important consequences for astrocyte Ca(2+) wave propagation, gliotransmission, and ultimately neuronal function. PMID:26631479

  3. Epigenetic Regulation by ATP-Dependent Chromatin-Remodeling Enzymes: SNF-ing Out Crosstalk.

    PubMed

    Runge, John S; Raab, Jesse R; Magnuson, Terry

    2016-01-01

    Cells utilize precise mechanisms to access genomic DNA with spatiotemporal accuracy. ATP-dependent chromatin-remodeling enzymes (also known simply as "remodelers") comprise a specialized class of enzymes that is intimately involved in genomic organization and accessibility. Remodelers selectively position nucleosomes to either alleviate chromatin compaction or achieve genomic condensation locally, based on a multitude of cellular signals. By dictating nucleosome position, remodelers control local euchromatic and heterochromatic states. These activities govern the accessibility of regulatory regions like promoters and enhancers to transcription factors, RNA polymerases, and coactivators or -repressors. As studies unravel the complexities of epigenetic topography, evidence points to a chromatin-based interactome where regulators interact competitively, cooperatively, and/or codependently through physical and functional means. These types of interactions, or crosstalk, between remodelers raise important questions for tissue development. Here, we briefly review the evidence for remodeler interactions and argue for additional studies examining crosstalk. PMID:26969969

  4. p21-activated kinase 4 regulates mitotic spindle positioning and orientation.

    PubMed

    Bompard, Guillaume; Morin, Nathalie

    2012-01-01

    During mitosis, microtubules (MTs) are massively rearranged into three sets of highly dynamic MTs that are nucleated from the centrosomes to form the mitotic spindle. Tight regulation of spindle positioning in the dividing cell and chromosome alignment at the center of the metaphase spindle are required to ensure perfect chromosome segregation and to position the cytokinetic furrow that will specify the two daughter cells. Spindle positioning requires regulation of MT dynamics, involving depolymerase activities together with cortical and kinetochore-mediated pushing and pulling forces acting on astral MTs and kinetochore fibres. These forces rely on MT motor activities. Cortical pulling forces exerted on astral MTs depend upon dynein/dynactin complexes and are essential in both symmetric and asymmetric cell division. A well-established spindle positioning pathway regulating the cortical targeting of dynein/dynactin involves the conserved LGN (Leu-Gly-Asn repeat-enriched-protein) and NuMA (microtubule binding nuclear mitotic apparatus protein) complex. Spindle orientation is also regulated by integrin-mediated cell adhesion and actin retraction fibres that respond to mechanical stress and are influenced by the microenvironment of the dividing cell. Altering the capture of astral MTs or modulating pulling forces affects spindle position, which can impair cell division, differentiation and embryogenesis. In this general scheme, the activity of mitotic kinases such as Auroras and Plk1 (Polo-like kinase 1) is crucial. Recently, the p21-activated kinases (PAKs) emerged as novel important players in mitotic progression. In our recent article, we demonstrated that PAK4 regulates spindle positioning in symmetric cell division. In this commentary, and in light of recent published studies, we discuss how PAK4 could participate in the regulation of mechanisms involved in spindle positioning and orientation. PMID:22960742

  5. Regulating the Intersection of Metabolism and Pathogenesis in Gram-positive Bacteria

    PubMed Central

    RICHARDSON, ANTHONY R.; SOMERVILLE, GREG A.; SONENSHEIN, ABRAHAM L.

    2015-01-01

    Pathogenic bacteria must contend with immune systems that actively restrict the availability of nutrients and cofactors, and create a hostile growth environment. To deal with these hostile environments, pathogenic bacteria have evolved or acquired virulence determinants that aid in the acquisition of nutrients. This connection between pathogenesis and nutrition may explain why regulators of metabolism in nonpathogenic bacteria are used by pathogenic bacteria to regulate both metabolism and virulence. Such coordinated regulation is presumably advantageous because it conserves carbon and energy by aligning synthesis of virulence determinants with the nutritional environment. In Gram-positive bacterial pathogens, at least three metabolite-responsive global regulators, CcpA, CodY, and Rex, have been shown to coordinate the expression of metabolism and virulence genes. In this chapter, we discuss how environmental challenges alter metabolism, the regulators that respond to this altered metabolism, and how these regulators influence the host-pathogen interaction. PMID:26185086

  6. Positioning.

    ERIC Educational Resources Information Center

    Conone, Ruth M.

    The key to positioning is the creation of a clear benefit image in the consumer's mind. One positioning strategy is creating in the prospect's mind a position that takes into consideration the company's or agency's strengths and weaknesses as well as those of its competitors. Another strategy is to gain entry into a position ladder owned by…

  7. miRNA863-3p sequentially targets negative immune regulator ARLPKs and positive regulator SERRATE upon bacterial infection

    PubMed Central

    Niu, Dongdong; Lii, Yifan E.; Chellappan, Padmanabhan; Lei, Lei; Peralta, Karl; Jiang, Chunhao; Guo, Jianhua; Coaker, Gitta; Jin, Hailing

    2016-01-01

    Plant small RNAs play important roles in gene regulation during pathogen infection. Here we show that miR863-3p is induced by the bacterial pathogen Pseudomonas syringae carrying various effectors. Early during infection, miR863-3p silences two negative regulators of plant defence, atypical receptor-like pseudokinase1 (ARLPK1) and ARLPK2, both lacking extracellular domains and kinase activity, through mRNA degradation to promote immunity. ARLPK1 associates with, and may function through another negative immune regulator ARLPK1-interacting receptor-like kinase 1 (AKIK1), an active kinase with an extracellular domain. Later during infection, miR863-3p silences SERRATE, which is essential for miRNA accumulation and positively regulates defence, through translational inhibition. This results in decreased miR863-3p levels, thus forming a negative feedback loop to attenuate immune responses after successful defence. This is an example of a miRNA that sequentially targets both negative and positive regulators of immunity through two modes of action to fine-tune the timing and amplitude of defence responses. PMID:27108563

  8. Positive Regulation of Botulinum Neurotoxin Gene Expression by CodY in Clostridium botulinum ATCC 3502

    PubMed Central

    Zhang, Zhen; Dahlsten, Elias; Korkeala, Hannu

    2014-01-01

    Botulinum neurotoxin, produced mainly by the spore-forming bacterium Clostridium botulinum, is the most poisonous biological substance known. Here, we show that CodY, a global regulator conserved in low-G+C Gram-positive bacteria, positively regulates the botulinum neurotoxin gene expression. Inactivation of codY resulted in decreased expression of botA, encoding the neurotoxin, as well as in reduced neurotoxin synthesis. Complementation of the codY mutation in trans rescued neurotoxin synthesis, and overexpression of codY in trans caused elevated neurotoxin production. Recombinant CodY was found to bind to a 30-bp region containing the botA transcription start site, suggesting regulation of the neurotoxin gene transcription through direct interaction. GTP enhanced the binding affinity of CodY to the botA promoter, suggesting that CodY-dependent neurotoxin regulation is associated with nutritional status. PMID:25281376

  9. CRP-dependent positive autoregulation and proteolytic degradation regulate competence activator Sxy of Escherichia coli.

    PubMed

    Jaskólska, Milena; Gerdes, Kenn

    2015-03-01

    Natural competence, the ability of bacteria to take up exogenous DNA and incorporate it into their chromosomes, is in most bacteria a transient phenomenon under complex genetic and environmental control. In the Gram-negative bacteria Haemophilus influenzae and Vibrio cholerae, the master regulator Sxy/TfoX controls competence development. Although not known to be naturally competent, Escherichia coli possesses a Sxy homologue and a competence regulon containing the genes required for DNA uptake. Here, we show that in contrast to other characterised Gamma-proteobacteria, E. coli Sxy is positively autoregulated at the level of transcription by a mechanism that requires cAMP receptor protein (CRP), cyclic AMP (cAMP) and a CRP-S site in the sxy promoter. Similarly, we found no evidence that Sxy expression in E. coli was regulated at the translational level. However, our analysis revealed that Sxy is an unstable protein and that its cellular level is negatively regulated at the post-translational level via degradation by Lon protease. Interestingly, in the Gram-positive model organism Bacillus subtilis, the competence master regulator ComK is also positively autoregulated at the level of transcription and negatively regulated by proteolysis. Together, these findings reveal striking similarities between the competence regulons of a Gram-positive and a Gram-negative bacterium. PMID:25491382

  10. Regulation of FGF signaling: Recent insights from studying positive and negative modulators.

    PubMed

    Korsensky, Lina; Ron, Dina

    2016-05-01

    Fibroblast growth factor (FGF) signaling is involved in a multitude of biological processes, while impairment of FGF signaling is implicated in a variety of human diseases including developmental disorders and cancer. Therefore, it is not surprising that FGF activity is regulated at multiple and distinct levels. This review focuses on positive and negative modulation of the FGF signal exemplified by recently identified protein modulators anosmin-1, fibronectin-leucine-rich transmembrane protein 3 (FLRT3) and similar expression to FGF (Sef). We examine how these proteins regulate FGF signaling at multiple levels and across species. Finally, we describe the role of these regulators in human disease. PMID:26903404

  11. Comparison of tryptophan biosynthetic operon regulation in different Gram-positive bacterial species.

    PubMed

    Gutiérrez-Preciado, Ana; Yanofsky, Charles; Merino, Enrique

    2007-09-01

    The tryptophan biosynthetic operon has been widely used as a model system for studying transcription regulation. In Bacillus subtilis, the trp operon is primarily regulated by a tryptophan-activated RNA-binding protein, TRAP. Here we show that in many other Gram-positive species the trp operon is regulated differently, by tRNA(Trp) sensing by the RNA-based T-box mechanism, with T-boxes arranged in tandem. Our analyses reveal an apparent relationship between trp operon organization and the specific regulatory mechanism(s) used. PMID:17555843

  12. Factor Structure and Initial Validation of a Multidimensional Measure of Difficulties in the Regulation of Positive Emotions: The DERS-Positive

    PubMed Central

    Weiss, Nicole H.; Gratz, Kim L.; Lavender, Jason M.

    2015-01-01

    Emotion regulation difficulties are a transdiagnostic construct relevant to numerous clinical difficulties. Although the Difficulties in Emotion Regulation Scale (Gratz & Roemer, 2004) is a multidimensional measure of maladaptive ways of responding to emotions, it focuses on difficulties with the regulation of negative emotions and does not assess emotion dysregulation in the form of problematic responding to positive emotions. The aim of this study was to develop and validate a measure of clinically-relevant difficulties in the regulation of positive emotions (DERS-Positive). Findings revealed a 3-factor structure and supported the internal consistency and construct validity of the total and subscale scores. PMID:25576185

  13. A positive role for polycomb in transcriptional regulation via H4K20me1

    PubMed Central

    Lv, Xiangdong; Han, Zhijun; Chen, Hao; Yang, Bo; Yang, Xiaofeng; Xia, Yuanxin; Pan, Chenyu; Fu, Lin; Zhang, Shuo; Han, Hui; Wu, Min; Zhou, Zhaocai; Zhang, Lei; Li, Lin; Wei, Gang; Zhao, Yun

    2016-01-01

    The highly conserved polycomb group (PcG) proteins maintain heritable transcription repression of the genes essential for development from fly to mammals. However, sporadic reports imply a potential role of PcGs in positive regulation of gene transcription, although systematic investigation of such function and the underlying mechanism has rarely been reported. Here, we report a Pc-mediated, H3K27me3-dependent positive transcriptional regulation of Senseless (Sens), a key transcription factor required for development. Mechanistic studies show that Pc regulates Sens expression by promoting H4K20me1 at the Sens locus. Further bioinformatic analysis at genome-wide level indicates that the existence of H4K20me1 acts as a selective mark for positive transcriptional regulation by Pc/H3K27me3. Both the intensities and specific patterns of Pc and H3K27me3 are important for the fates of target gene transcription. Moreover, binding of transcription factor Broad (Br), which physically interacts with Pc and positively regulates the transcription of Sens, is observed in Pc+H3K27me3+H4K20me1+ genes, but not in Pc+H3K27me3+H4K20me1− genes. Taken together, our study reveals that, coupling with the transcription factor Br, Pc positively regulates transcription of Pc+H3K27me3+H4K20me1+ genes in developing Drosophila wing disc. PMID:27002220

  14. Positive and negative roles for soybean MPK6 in regulating defense responses

    Technology Transfer Automated Retrieval System (TEKTRAN)

    It has been well established that MPK6 is a positive regulator of defense responses in model plants such as Arabidopsis and tobacco. However, the functional importance of soybean MPK6 in disease resistance has not been investigated. Here, we showed that silencing of GmMPK6 in soybean using virus-ind...

  15. 77 FR 60343 - Federal Acquisition Regulation; Positive Law Codification of Title 41

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-10-03

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF DEFENSE GENERAL SERVICES ADMINISTRATION NATIONAL AERONAUTICS AND SPACE ADMINISTRATION 48 CFR Part 53 RIN 9000-AM30 Federal Acquisition Regulation; Positive Law Codification of Title 41 Correction In proposed rule...

  16. Maternal Socialization of Positive Affect: The Impact of Invalidation on Adolescent Emotion Regulation and Depressive Symptomatology

    ERIC Educational Resources Information Center

    Yap, Marie B. H.; Allen, Nicholas B.; Ladouceur, Cecile D.

    2008-01-01

    This study examined the relations among maternal socialization of positive affect (PA), adolescent emotion regulation (ER), and adolescent depressive symptoms. Two hundred early adolescents, 11-13 years old, provided self-reports of ER strategies and depressive symptomatology; their mothers provided self-reports of socialization responses to…

  17. Exercise temperature regulation in man in the upright and supine positions.

    NASA Technical Reports Server (NTRS)

    Greenleaf, J. E.; Card, D. H.; Rapport, M.; Van Kessel, A. L.; Ruff, W.

    1971-01-01

    Rectal, auditory canal, and mean skin temperatures and various metabolic measurements were taken on subjects during 70-min exercise periods, in the upright and supine positions, on a bicycle ergometer. The results indicate nonlinear relationships between sweating and core skin temperatures and suggest the action of undefined thermal and/or nonthermal inputs in the control of exercise temperature regulation.

  18. 78 FR 70191 - Post-Employment Conflict of Interest Regulations; Exempted Senior Employee Positions; Withdrawal...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-11-25

    ... Regulations; Exempted Senior Employee Positions'' published October 3, 2013, at 78 FR 61153. DATES: Effective Date: The final rule published on October 3, 2013, at 78 FR 61153 is withdrawn, effective November 25... in the Federal Register, at 78 FR 61153, concerning the revocation of certain regulatory...

  19. Aurora A kinase regulates proper spindle positioning in C. elegans and in human cells.

    PubMed

    Kotak, Sachin; Afshar, Katayon; Busso, Coralie; Gönczy, Pierre

    2016-08-01

    Accurate spindle positioning is essential for error-free cell division. The one-cell Caenorhabditis elegans embryo has proven instrumental for dissecting mechanisms governing spindle positioning. Despite important progress, how the cortical forces that act on astral microtubules to properly position the spindle are modulated is incompletely understood. Here, we report that the PP6 phosphatase PPH-6 and its associated subunit SAPS-1, which positively regulate pulling forces acting on spindle poles, associate with the Aurora A kinase AIR-1 in C. elegans embryos. We show that acute inactivation of AIR-1 during mitosis results in excess pulling forces on astral microtubules. Furthermore, we uncover that AIR-1 acts downstream of PPH-6-SAPS-1 in modulating spindle positioning, and that PPH-6-SAPS-1 negatively regulates AIR-1 localization at the cell cortex. Moreover, we show that Aurora A and the PP6 phosphatase subunit PPP6C are also necessary for spindle positioning in human cells. There, Aurora A is needed for the cortical localization of NuMA and dynein during mitosis. Overall, our work demonstrates that Aurora A kinases and PP6 phosphatases have an ancient function in modulating spindle positioning, thus contributing to faithful cell division. PMID:27335426

  20. Positive feedback regulation of type I interferon by the interferon-stimulated gene STING

    PubMed Central

    Ma, Feng; Li, Bing; Yu, Yongxin; Iyer, Shankar S; Sun, Mingyu; Cheng, Genhong

    2015-01-01

    Stimulator of interferon genes (STING) is an important regulator of the innate immune response to cytoplasmic DNA. However, regulation of STING itself is largely unknown. Here, we show that STING transcription is induced by innate immune activators, such as cyclic dinucleotides (CDNs), through an IFNAR1- and STAT1-dependent pathway. We also identify a STAT1 binding site in the STING promoter that contributes to the activation of STING transcription. Furthermore, we show that induction of STING mediates the positive feedback regulation of CDN-triggered IFN-I. Thus, our study demonstrates that STING is an interferon-stimulated gene (ISG) and its induction is crucial for the IFN-I positive feedback loop. PMID:25572843

  1. New insights into regulation of the tryptophan biosynthetic operon in Gram-positive bacteria.

    PubMed

    Gutierrez-Preciado, A; Jensen, R A; Yanofsky, C; Merino, E

    2005-08-01

    The tryptophan operon of Bacillus subtilis serves as an excellent model for investigating transcription regulation in Gram-positive bacteria. In this article, we extend this knowledge by analyzing the predicted regulatory regions in the trp operons of other fully sequenced Gram-positive bacteria. Interestingly, it appears that in eight of the organisms examined, transcription of the trp operon appears to be regulated by tandem T-box elements. These regulatory elements have recently been described in the trp operons of two bacterial species. Single T-box elements are commonly found in Gram-positive bacteria in operons encoding aminoacyl tRNA synthetases and proteins performing other functions. Different regulatory mechanisms appear to be associated with variations of trp gene organization within the trp operon. PMID:15953653

  2. Expansion of a 12-kb VNTR containing the REXO1L1 gene cluster underlies the microscopically visible euchromatic variant of 8q21.2

    PubMed Central

    Tyson, Christine; Sharp, Andrew J; Hrynchak, Monica; Yong, Siu L; Hollox, Edward J; Warburton, Peter; Barber, John CK

    2014-01-01

    Copy number variants visible with the light microscope have been described as euchromatic variants (EVs) and EVs with extra G-light material at 8q21.2 have been reported only once before. We report four further patients with EVs of 8q21.2 ascertained for clinical (3) or reproductive reasons (1). Enhanced signal strength from two overlapping bacterial artificial chromosomes (BACs) and microarray analysis mapped the EV to a 284-kb interval in the reference genome. This interval consists of a sequence gap flanked by segmental duplications that contain the 12-kb components of one of the largest Variable Number Tandem Repeat arrays in the human genome. Using digital NanoString technology with a custom probe for the RNA exonuclease 1 homologue (S. cerevisiae)-like 1 (REXO1L1) gene within each 12-kb repeat, significantly enhanced diploid copy numbers of 270 and 265 were found in an EV family and a median diploid copy number of 166 copies in 216 controls. These 8q21.2 EVs are not thought to have clinical consequences as the phenotypes of the probands were inconsistent, those referred for reproductive reasons were otherwise phenotypically normal and the REXO1L1 gene has no known disease association. This EV was found in 4/3078 (1 in 770) consecutive referrals for chromosome analysis and needs to be distinguished from pathogenic imbalances of medial 8q. The REXO1L1 gene product is a marker of hepatitis C virus (HCV) infection and a possible association between REXO1L1 copy number and susceptibility to HCV infection, progression or response to treatment has not yet been excluded. PMID:24045839

  3. Social anxiety and emotion regulation in daily life: spillover effects on positive and negative social events.

    PubMed

    Farmer, Antonina Savostyanova; Kashdan, Todd B

    2012-01-01

    To minimize the possibility of scrutiny, people with social anxiety difficulties exert great effort to manage their emotions, particularly during social interactions. We examined how the use of two emotion regulation strategies, emotion suppression and cognitive reappraisal, predict the generation of emotions and social events in daily life. Over 14 consecutive days, 89 participants completed daily diary entries on emotions, positive and negative social events, and their regulation of emotions. Using multilevel modeling, we found that when people high in social anxiety relied more on positive emotion suppression, they reported fewer positive social events and less positive emotion on the subsequent day. In contrast, people low in social anxiety reported fewer negative social events on days subsequent to using cognitive reappraisal to reduce distress; the use of cognitive reappraisal did not influence the daily lives of people high in social anxiety. Our findings support theories of emotion regulation difficulties associated with social anxiety. In particular, for people high in social anxiety, maladaptive strategy use contributed to diminished reward responsiveness. PMID:22428662

  4. The Mechanisms of Virulence Regulation by Small Noncoding RNAs in Low GC Gram-Positive Pathogens

    PubMed Central

    Pitman, Stephanie; Cho, Kyu Hong

    2015-01-01

    The discovery of small noncoding regulatory RNAs (sRNAs) in bacteria has grown tremendously recently, giving new insights into gene regulation. The implementation of computational analysis and RNA sequencing has provided new tools to discover and analyze potential sRNAs. Small regulatory RNAs that act by base-pairing to target mRNAs have been found to be ubiquitous and are the most abundant class of post-transcriptional regulators in bacteria. The majority of sRNA studies has been limited to E. coli and other gram-negative bacteria. However, examples of sRNAs in gram-positive bacteria are still plentiful although the detailed gene regulation mechanisms behind them are not as well understood. Strict virulence control is critical for a pathogen’s survival and many sRNAs have been found to be involved in that process. This review outlines the targets and currently known mechanisms of trans-acting sRNAs involved in virulence regulation in various gram-positive pathogens. In addition, their shared characteristics such as CU interaction motifs, the role of Hfq, and involvement in two-component regulators, riboswitches, quorum sensing, or toxin/antitoxin systems are described. PMID:26694351

  5. Interaction with the Yes-associated protein (YAP) allows TEAD1 to positively regulate NAIP expression.

    PubMed

    Landin Malt, André; Georges, Adrien; Silber, Joël; Zider, Alain; Flagiello, Domenico

    2013-10-01

    Although the expression of the neuronal apoptosis inhibitory protein (NAIP) gene is considered involved in apoptosis suppression as well as in inflammatory response, the molecular basis of the NAIP gene expression is poorly understood. Here we show that the TEA domain protein 1 (TEAD1) is able to positively activate the transcription of NAIP. We further demonstrate that this regulation is mediated by the presence of the endogenous Yes associated protein (YAP) cofactor, and requires the interaction with YAP. We finally identified an intronic region of the NAIP gene responding to TEAD1/YAP activity, suggesting that regulation of NAIP by TEAD1/YAP is at the transcriptional level. PMID:23994529

  6. Fresh layers of RNA-mediated regulation in Gram-positive bacteria.

    PubMed

    Bouloc, Philippe; Repoila, Francis

    2016-04-01

    Bacterial regulatory RNAs have been defined as diverse classes of cis and trans elements that may intervene at each step of gene expression, from RNA and protein synthesis to degradation. Here, we report on a few examples from Gram-positive bacteria that extend the definition of regulatory RNAs to include 5' and 3' UTRs that also act as cis and trans regulators. New examples unveil the existence of cis and trans acting regulatory RNAs on a single molecule. Also, we highlight data showing that a key RNA chaperone in Enterobacteriaceae, Hfq, does not fulfill the same role in Gram-positive Firmicutes. PMID:26773797

  7. China's position in negotiating the Framework Convention on Tobacco Control and the revised International Health Regulations.

    PubMed

    Huang, Y

    2014-02-01

    This paper examines China's position in the negotiations of the Framework Convention on Tobacco Control and the revised International Health Regulations. In particular, it explores three sets of factors shaping China's attitudes and actions in the negotiations: the aspiration to be a responsible power; concerns about sovereignty; and domestic political economy. In both cases, China demonstrated strong incentives to participate in the negotiation of legally binding international rules. Still, the sovereignty issue was a major, if not the biggest, concern for China when engaging in global health rule making. The two cases also reveal domestic political economy as an important factor in shaping China's position in international health negotiations. PMID:24370173

  8. Intracellular osteopontin stabilizes TRAF3 to positively regulate innate antiviral response

    PubMed Central

    Zhao, Kai; Zhang, Meng; Zhang, Lei; Wang, Peng; Song, Guanhua; Liu, Bingyu; Wu, Haifeng; Yin, Zhinan; Gao, Chengjiang

    2016-01-01

    Osteopontin (OPN) is a multifunctional protein involved in both innate immunity and adaptive immunity. However, the function of OPN, especially the intracellular form OPN (iOPN) on innate antiviral immune response remains elusive. Here, we demonstrated that iOPN is an essential positive regulator to protect the host from virus infection. OPN deficiency or knockdown significantly attenuated virus-induced IRF3 activation, IFN-β production and antiviral response. Consistently, OPN-deficient mice were more susceptible to VSV infection than WT mice. Mechanistically, iOPN was found to interact with tumor necrosis factor receptor (TNFR)-associated factor 3 (TRAF3) and inhibit Triad3A-mediated K48-linked polyubiquitination and degradation of TRAF3 through the C-terminal fragment of iOPN. Therefore, our findings delineated a new function for iOPN to act as a positive regulator in innate antiviral immunity through stabilization of TRAF3. PMID:27026194

  9. Microbe–Host Interactions are Positively and Negatively Regulated by Galectin–Glycan Interactions

    PubMed Central

    Baum, Linda G.; Garner, Omai B.; Schaefer, Katrin; Lee, Benhur

    2014-01-01

    Microbe–host interactions are complex processes that are directly and indirectly regulated by a variety of factors, including microbe presentation of specific molecular signatures on the microbial surface, as well as host cell presentation of receptors that recognize these pathogen signatures. Cell surface glycans are one important class of microbial signatures that are recognized by a variety of host cell lectins. Host cell lectins that recognize microbial glycans include members of the galectin family of lectins that recognize specific glycan ligands on viruses, bacteria, fungi, and parasites. In this review, we will discuss the ways that the interactions of microbial glycans with host cell galectins positively and negatively regulate pathogen attachment, invasion, and survival, as well as regulate host responses that mitigate microbial pathogenesis. PMID:24995007

  10. A balance of positive and negative regulators determines the pace of the segmentation clock

    PubMed Central

    Wiedermann, Guy; Bone, Robert Alexander; Silva, Joana Clara; Bjorklund, Mia

    2015-01-01

    Somitogenesis is regulated by a molecular oscillator that drives dynamic gene expression within the pre-somitic mesoderm. Previous mathematical models of the somitogenesis clock that invoke the mechanism of delayed negative feedback predict that its oscillation period depends on the sum of delays inherent to negative-feedback loops and inhibitor half-lives. We develop a mathematical model that explores the possibility that positive feedback also plays a role in determining the period of clock oscillations. The model predicts that increasing the half-life of the positive regulator, Notch intracellular domain (NICD), can lead to elevated NICD levels and an increase in the oscillation period. To test this hypothesis, we investigate a phenotype induced by various small molecule inhibitors in which the clock is slowed. We observe elevated levels and a prolonged half-life of NICD. Reducing NICD production rescues these effects. These data provide the first indication that tight control of the turnover of positive as well as negative regulators of the clock determines its periodicity. DOI: http://dx.doi.org/10.7554/eLife.05842.001 PMID:26357015

  11. OsGF14b Positively Regulates Panicle Blast Resistance but Negatively Regulates Leaf Blast Resistance in Rice.

    PubMed

    Liu, Qing; Yang, Jianyuan; Zhang, Shaohong; Zhao, Junliang; Feng, Aiqing; Yang, Tifeng; Wang, Xiaofei; Mao, Xinxue; Dong, Jingfang; Zhu, Xiaoyuan; Leung, Hei; Leach, Jan E; Liu, Bin

    2016-01-01

    Although 14-3-3 proteins have been reported to be involved in responses to biotic stresses in plants, their functions in rice blast, the most destructive disease in rice, are largely unknown. Only GF14e has been confirmed to negatively regulate leaf blast. We report that GF14b is highly expressed in seedlings and panicles during blast infection. Rice plants overexpressing GF14b show enhanced resistance to panicle blast but are susceptible to leaf blast. In contrast, GF14b-silenced plants show increased susceptibility to panicle blast but enhanced resistance to leaf blast. Yeast one-hybrid assays demonstrate that WRKY71 binds to the promoter of GF14b and modulates its expression. Overexpression of GF14b induces expression of jasmonic acid (JA) synthesis-related genes but suppresses expression of salicylic acid (SA) synthesis-related genes. In contrast, suppressed GF14b expression causes decreased expression of JA synthesis-related genes but activation of SA synthesis-related genes. These results suggest that GF14b positively regulates panicle blast resistance but negatively regulates leaf blast resistance, and that GF14b-mediated disease resistance is associated with the JA- and SA-dependent pathway. The different functions for 14-3-3 proteins in leaf and panicle blast provide new evidence that leaf and panicle blast resistance are controlled by different mechanisms. PMID:26467468

  12. Nitric Oxide Acts as a Positive Regulator to Induce Metamorphosis of the Ascidian Herdmania momus

    PubMed Central

    Ueda, Nobuo; Degnan, Sandie M.

    2013-01-01

    Marine invertebrates commonly have a biphasic life cycle in which the metamorphic transition from a pelagic larva to a benthic post-larva is mediated by the nitric oxide signalling pathway. Nitric oxide (NO) is synthesised by nitric oxide synthase (NOS), which is a client protein of the molecular chaperon heat shock protein 90 (HSP90). It is notable, then, that both NO and HSP90 have been implicated in regulating metamorphosis in marine invertebrates as diverse as urochordates, echinoderms, molluscs, annelids, and crustaceans. Specifically, the suppression of NOS activity by the application of either NOS- or HSP90-inhibiting pharmacological agents has been shown consistently to induce the initiation of metamorphosis, leading to the hypothesis that a negative regulatory role of NO is widely conserved in biphasic life cycles. Further, the induction of metamorphosis by heat-shock has been demonstrated for multiple species. Here, we investigate the regulatory role of NO in induction of metamorphosis of the solitary tropical ascidian, Herdmania momus. By coupling pharmacological treatments with analysis of HmNOS and HmHSP90 gene expression, we present compelling evidence of a positive regulatory role for NO in metamorphosis of this species, in contrast to all existing ascidian data that supports the hypothesis of NO as a conserved negative regulator of metamorphosis. The exposure of competent H. momus larvae to a NOS inhibitor or an NO donor results in an up-regulation of NOS and HSP90 genes. Heat shock of competent larvae induces metamorphosis in a temperature dependent manner, up to a thermal tolerance that approaches 35°C. Both larval/post-larval survival and the appearance of abnormal morphologies in H. momus post-larvae reflect the magnitude of up-regulation of the HSP90 gene in response to heat-shock. The demonstrated role of NO as a positive metamorphic regulator in H. momus suggests the existence of inter-specific adaptations of NO regulation in ascidian

  13. Spatial organization of the extracellular matrix regulates cell–cell junction positioning

    PubMed Central

    Tseng, Qingzong; Duchemin-Pelletier, Eve; Deshiere, Alexandre; Balland, Martial; Guillou, Hervé; Filhol, Odile; Théry, Manuel

    2012-01-01

    The organization of cells into epithelium depends on cell interaction with both the extracellular matrix (ECM) and adjacent cells. The role of cell–cell adhesion in the regulation of epithelial topology is well-described. ECM is better known to promote cell migration and provide a structural scaffold for cell anchoring, but its contribution to multicellular morphogenesis is less well-understood. We developed a minimal model system to investigate how ECM affects the spatial organization of intercellular junctions. Fibronectin micropatterns were used to constrain the location of cell–ECM adhesion. We found that ECM affects the degree of stability of intercellular junction positioning and the magnitude of intra- and intercellular forces. Intercellular junctions were permanently displaced, and experienced large perpendicular tensional forces as long as they were positioned close to ECM. They remained stable solely in regions deprived of ECM, where they were submitted to lower tensional forces. The heterogeneity of the spatial organization of ECM induced anisotropic distribution of mechanical constraints in cells, which seemed to adapt their position to minimize both intra- and intercellular forces. These results uncover a morphogenetic role for ECM in the mechanical regulation of cells and intercellular junction positioning. PMID:22307605

  14. Positive and negative regulation of the human heme oxygenase-1 gene expression in cultured cells.

    PubMed

    Takahashi, S; Takahashi, Y; Ito, K; Nagano, T; Shibahara, S; Miura, T

    1999-10-28

    To elucidate the regulation of the human heme oxygenase-1 (hHO-1) gene expression, we assessed approximately 4 kb of the 5'-flanking region of the hHO-1 gene for basal promoter activity and sequenced approximately 2 kb of the 5'-flanking region. A series of deletion mutants of the 5'-flanking region linked to the luciferase gene was constructed. Basal level expression of these constructs was tested in HepG2 human hepatoma cells and HeLa cervical cancer cells. By measuring luciferase activity, which was transiently expressed in the transfected cells, we found a positive regulatory region at position -1976 to -1655 bp. This region functions in HepG2 cells but not in HeLa cells. A negative regulatory region was also found at position -981 to -412 bp that functions in both HepG2 cells and HeLa cells. PMID:10542320

  15. Soybean Homologs of MPK4 Negatively Regulate Defense Responses and Positively Regulate Growth and Development1[W][OA

    PubMed Central

    Liu, Jian-Zhong; Horstman, Heidi D.; Braun, Edward; Graham, Michelle A.; Zhang, Chunquan; Navarre, Duroy; Qiu, Wen-Li; Lee, Yeunsook; Nettleton, Dan; Hill, John H.; Whitham, Steven A.

    2011-01-01

    Mitogen-activated protein kinase (MAPK) cascades play important roles in disease resistance in model plant species such as Arabidopsis (Arabidopsis thaliana) and tobacco (Nicotiana tabacum). However, the importance of MAPK signaling pathways in the disease resistance of crops is still largely uninvestigated. To better understand the role of MAPK signaling pathways in disease resistance in soybean (Glycine max), 13, nine, and 10 genes encoding distinct MAPKs, MAPKKs, and MAPKKKs, respectively, were silenced using virus-induced gene silencing mediated by Bean pod mottle virus. Among the plants silenced for various MAPKs, MAPKKs, and MAPKKKs, those in which GmMAPK4 homologs (GmMPK4s) were silenced displayed strong phenotypes including stunted stature and spontaneous cell death on the leaves and stems, the characteristic hallmarks of activated defense responses. Microarray analysis showed that genes involved in defense responses, such as those in salicylic acid (SA) signaling pathways, were significantly up-regulated in GmMPK4-silenced plants, whereas genes involved in growth and development, such as those in auxin signaling pathways and in cell cycle and proliferation, were significantly down-regulated. As expected, SA and hydrogen peroxide accumulation was significantly increased in GmMPK4-silenced plants. Accordingly, GmMPK4-silenced plants were more resistant to downy mildew and Soybean mosaic virus compared with vector control plants. Using bimolecular fluorescence complementation analysis and in vitro kinase assays, we determined that GmMKK1 and GmMKK2 might function upstream of GmMPK4. Taken together, our results indicate that GmMPK4s negatively regulate SA accumulation and defense response but positively regulate plant growth and development, and their functions are conserved across plant species. PMID:21878550

  16. Expression of POEM, a positive regulator of osteoblast differentiation, is suppressed by TNF-{alpha}

    SciTech Connect

    Tsukasaki, Masayuki; Yamada, Atsushi; Suzuki, Dai; Aizawa, Ryo; Miyazono, Agasa; Miyamoto, Yoichi; Suzawa, Tetsuo; Takami, Masamichi; Yoshimura, Kentaro; Morimura, Naoko; Yamamoto, Matsuo; Kamijo, Ryutaro

    2011-07-15

    Highlights: {yields} TNF-{alpha} inhibits POEM gene expression. {yields} Inhibition of POEM gene expression is caused by NF-{kappa}B activation by TNF-{alpha}. {yields} Over-expression of POEM recovers inhibition of osteoblast differentiation by TNF-{alpha}. -- Abstract: POEM, also known as nephronectin, is an extracellular matrix protein considered to be a positive regulator of osteoblast differentiation. In the present study, we found that tumor necrosis factor-{alpha} (TNF-{alpha}), a key regulator of bone matrix properties and composition that also inhibits terminal osteoblast differentiation, strongly inhibited POEM expression in the mouse osteoblastic cell line MC3T3-E1. TNF-{alpha}-induced down-regulation of POEM gene expression occurred in both time- and dose-dependent manners through the nuclear factor kappa B (NF-{kappa}B) pathway. In addition, expressions of marker genes in differentiated osteoblasts were down-regulated by TNF-{alpha} in a manner consistent with our findings for POEM, while over-expression of POEM recovered TNF-{alpha}-induced inhibition of osteoblast differentiation. These results suggest that TNF-{alpha} inhibits POEM expression through the NF-{kappa}B signaling pathway and down-regulation of POEM influences the inhibition of osteoblast differentiation by TNF-{alpha}.

  17. Identification of E2F1 as a positive transcriptional regulator for {delta}-catenin

    SciTech Connect

    Kim, Kwonseop; Oh, Minsoo; Ki, Hyunkyoung; Wang Tao; Bareiss, Sonja; Fini, M. Elizabeth.; Li Dawei; Lu Qun

    2008-05-02

    {delta}-Catenin is upregulated in human carcinomas. However, little is known about the potential transcriptional factors that regulate {delta}-catenin expression in cancer. Using a human {delta}-catenin reporter system, we have screened several nuclear signaling modulators to test whether they can affect {delta}-catenin transcription. Among {beta}-catenin/LEF-1, Notch1, and E2F1, E2F1 dramatically increased {delta}-catenin-luciferase activities while {beta}-catenin/LEF-1 induced only a marginal increase. Rb suppressed the upregulation of {delta}-catenin-luciferase activities induced by E2F1 but did not interact with {delta}-catenin. RT-PCR and Western blot analyses in 4 different prostate cancer cell lines revealed that regulation of {delta}-catenin expression is controlled mainly at the transcriptional level. Interestingly, the effects of E2F1 on {delta}-catenin expression were observed only in human cancer cells expressing abundant endogenous {delta}-catenin. These studies identify E2F1 as a positive transcriptional regulator for {delta}-catenin, but further suggest the presence of strong negative regulator(s) for {delta}-catenin in prostate cancer cells with minimal endogenous {delta}-catenin expression.

  18. A positive feedback regulation of ISL-1 in DLBCL but not in pancreatic β-cells

    SciTech Connect

    Zhang, Qiao; Yang, Zhe; Wang, Weiping; Guo, Ting; Jia, Zhuqing; Ma, Kangtao; Zhou, Chunyan

    2014-07-04

    Highlights: • ISL-1 is highly expressed in human pancreatic β-cells and DLBCL. • ISL-1 accelerates the tumorigenesis of DLBCL in vivo. • c-Myc positively regulates ISL-1 expression in DLBCL but not in pancreatic β-cells. • ISL-1 and c-Myc forms an ISL-1/c-Myc transcriptional complex only in DLBCL. • Positive feedback regulation of ISL-1 does not exist in normal pancreatic β-cell. - Abstract: Insulin enhancer binding protein-1 (ISL-1), a LIM-homeodomain transcription factor, has been reported to play essential roles in promoting adult pancreatic β-cells proliferation. Recent studies indicate that ISL-1 may also involve in the occurrence of a variety of tumors. However, whether ISL-1 has any functional effect on tumorigenesis, and what are the differences on ISL-1 function in distinct conditions, are completely unknown. In this study, we found that ISL-1 was highly expressed in human pancreatic β-cells, as well as in diffuse large B cell lymphoma (DLBCL), but to a much less extent in other normal tissues or tumor specimens. Further study revealed that ISL-1 promoted the proliferation of pancreatic β-cells and DLBCL cells, and also accelerated the tumorigenesis of DLBCL in vivo. We also found that ISL-1 could activate c-Myc transcription not only in pancreatic β-cells but also in DLBCL cells. However, a cell-specific feedback regulation was detectable only in DLBCL cells. This auto-regulatory loop was established by the interaction of ISL-1 and c-Myc to form an ISL-1/c-Myc transcriptional complex, and synergistically to promote ISL-1 transcription through binding on the ISL-1 promoter. Taken together, our results demonstrate a positive feedback regulation of ISL-1 in DLBCL but not in pancreatic β-cells, which might result in the functional diversities of ISL-1 in different physiological and pathological processes.

  19. The unique regulation of iron-sulfur cluster biogenesis in a Gram-positive bacterium

    PubMed Central

    Santos, Joana A.; Alonso-García, Noelia; Macedo-Ribeiro, Sandra; Pereira, Pedro José Barbosa

    2014-01-01

    Iron-sulfur clusters function as cofactors of a wide range of proteins, with diverse molecular roles in both prokaryotic and eukaryotic cells. Dedicated machineries assemble the clusters and deliver them to the final acceptor molecules in a tightly regulated process. In the prototypical Gram-negative bacterium Escherichia coli, the two existing iron-sulfur cluster assembly systems, iron-sulfur cluster (ISC) and sulfur assimilation (SUF) pathways, are closely interconnected. The ISC pathway regulator, IscR, is a transcription factor of the helix-turn-helix type that can coordinate a [2Fe-2S] cluster. Redox conditions and iron or sulfur availability modulate the ligation status of the labile IscR cluster, which in turn determines a switch in DNA sequence specificity of the regulator: cluster-containing IscR can bind to a family of gene promoters (type-1) whereas the clusterless form recognizes only a second group of sequences (type-2). However, iron-sulfur cluster biogenesis in Gram-positive bacteria is not so well characterized, and most organisms of this group display only one of the iron-sulfur cluster assembly systems. A notable exception is the unique Gram-positive dissimilatory metal reducing bacterium Thermincola potens, where genes from both systems could be identified, albeit with a diverging organization from that of Gram-negative bacteria. We demonstrated that one of these genes encodes a functional IscR homolog and is likely involved in the regulation of iron-sulfur cluster biogenesis in T. potens. Structural and biochemical characterization of T. potens and E. coli IscR revealed a strikingly similar architecture and unveiled an unforeseen conservation of the unique mechanism of sequence discrimination characteristic of this distinctive group of transcription regulators. PMID:24847070

  20. The Role of Positive Personality Traits in Emotion Regulation of Patients with Irritable Bowel Syndrome (IBS)

    PubMed Central

    MAZAHERI, Mina; NIKNESHAN, Shekoufeh; DAGHAGHZADEH, Hamed; AFSHAR, Hamid

    2015-01-01

    Background: Personality traits and emotion regulation processes play an important role in human health. The purpose of this study was to investigate the role of positive personality traits (psychological hardiness and interpersonal forgiveness) in emotion regulation of patients with Irritable Bowel Syndrome. Methods: The research was a cross-sectional study. Statistical population included all of IBS patients referred to the Subspecialty Center of Psychiatry in Isfahan in 2013. Overall, 123 subjects (100 women, 83.3%, and 30 men, 16.7%) were selected by census method, according to criteria of research and during a particular period. To collect data, the Difficulties in Emotion Regulation Scale (DERS), Lang and Goulet Hardiness Scale (LGHS) and Interpersonal forgiveness Inventory (IFI) were used. Data was analyzed using Pearson’s correlation coefficient and Multivariate and Binary Logistic regression analyses. Results: Mean age of patients was 33.82±10.45 years and 83.3% (100) of them were female. Regression analyses showed that both personality traits of hardiness and forgiveness were as protective factors for emotional dysregulation with OR, 95% CI: 0.93 and 0.96 sequentially, with adjusting demographic variables (age, gender, and education level and disease duration). Conclusion: Patients who are more hardy and forgiving toward others, are likely more successful at adaptive emotion regulation. It emphasizes the positive and beneficial role of the personality traits in regulating of emotional problems of IBS patients. Hence, these variables should be considered as effective factors in the treatment process of the patients. PMID:26056675

  1. KCTD20, a relative of BTBD10, is a positive regulator of Akt

    PubMed Central

    2013-01-01

    Background BTBD10 binds to Akt and protein phosphatase 2A (PP2A) and inhibits the PP2A-mediated dephosphorylation of Akt, thereby keeping Akt activated. Previous studies have suggested that BTBD10 plays an important role in preventing motor neuronal death and accelerating the growth of pancreatic beta cells. Because levels of BTBD10 expression are much lower in many non-nervous tissues than nervous tissues, there may be a relative of BTBD10 that has BTBD10-like function in non-neuronal cells. Results A 419-amino-acid BTBD10-like protein, named KCTD20 (potassium channel tetramerization protein domain containing 20), was to found to bind to all Akt isoforms and PP2A. Overexpression of KCTD20 increased Akt phosphorylation at Thr308, as BTBD10 did, which suggests that KCTD20 as well as BTBD10 positively regulates the function of Akt. KCTD20 was ubiquitously expressed in non-nervous as well as nervous tissues. Conclusions KCTD20 is a positive regulator of Akt and may play an important role in regulating the death and growth of some non-nervous and nervous cells. PMID:24156551

  2. [Regulation of Positive and Negative Emotions as Mediator between Maternal Emotion Socialization and Child Problem Behavior].

    PubMed

    Fäsche, Anika; Gunzenhauser, Catherine; Friedlmeier, Wolfgang; von Suchodoletz, Antje

    2015-01-01

    The present study investigated five to six year old children's ability to regulate negative and positive emotions in relation to psychosocial problem behavior (N=53). It was explored, whether mothers' supportive and nonsupportive strategies of emotion socialization influence children's problem behavior by shaping their emotion regulation ability. Mothers reported on children's emotion regulation and internalizing and externalizing problem behavior via questionnaire, and were interviewed about their preferences for socialization strategies in response to children's expression of negative affect. Results showed that children with more adaptive expression of adequate positive emotions had less internalizing behavior problems. When children showed more control of inadequate negative emotions, children were less internalizing as well as externalizing in their behavior. Furthermore, results indicated indirect relations of mothers' socialization strategies with children's problem behavior. Control of inadequate negative emotions mediated the link between non-supportive strategies on externalizing problem behavior. Results suggest that emotion regulatory processes should be part of interventions to reduce the development of problematic behavior in young children. Parents should be trained in dealing with children's emotions in a constructive way. PMID:26032031

  3. Positive Feedback Regulation of stgR Expression for Secondary Metabolism in Streptomyces coelicolor

    PubMed Central

    Mao, Xu-Ming; Sun, Zhi-Hao; Liang, Bi-Rong; Wang, Zhi-Bin; Feng, Wei-Hong; Huang, Fang-Liang

    2013-01-01

    LysR-type transcriptional regulators (LTTRs) compose a large family and are responsible for various physiological functions in bacteria, while little is understood about their regulatory mechanism on secondary metabolism in Streptomyces. Here we reported that StgR, a typical LTTR in Streptomyces coelicolor, was a negative regulator of undecylprodigiosin (Red) and γ-actinorhodin (Act) production in the early developmental phase of secondary metabolism by suppressing the expression of two pathway-specific regulator genes, redD and actII-orf4, respectively. Meanwhile, stgR expression was downregulated during secondary metabolism to remove its repressive effects on antibiotic production. Moreover, stgR expression was positively autoregulated by direct binding of StgR to its own promoter (stgRp), and the binding site adjacent to translation start codon was determined by a DNase I footprinting assay. Furthermore, the StgR-stgRp interaction could be destroyed by the antibiotic γ-actinorhodin produced from S. coelicolor. Thus, our results suggested a positive feedback regulatory mechanism of stgR expression and antibiotic production for the rapid and irreversible development of secondary metabolism in Streptomyces. PMID:23457252

  4. Flattop regulates basal body docking and positioning in mono- and multiciliated cells

    PubMed Central

    Gegg, Moritz; Böttcher, Anika; Burtscher, Ingo; Hasenoeder, Stefan; Van Campenhout, Claude; Aichler, Michaela; Walch, Axel; Grant, Seth G N; Lickert, Heiko

    2014-01-01

    Planar cell polarity (PCP) regulates basal body (BB) docking and positioning during cilia formation, but the underlying mechanisms remain elusive. In this study, we investigate the uncharacterized gene Flattop (Fltp) that is transcriptionally activated during PCP acquisition in ciliated tissues. Fltp knock-out mice show BB docking and ciliogenesis defects in multiciliated lung cells. Furthermore, Fltp is necessary for kinocilium positioning in monociliated inner ear hair cells. In these cells, the core PCP molecule Dishevelled 2, the BB/spindle positioning protein Dlg3, and Fltp localize directly adjacent to the apical plasma membrane, physically interact and surround the BB at the interface of the microtubule and actin cytoskeleton. Dlg3 and Fltp knock-outs suggest that both cooperatively translate PCP cues for BB positioning in the inner ear. Taken together, the identification of novel BB/spindle positioning components as potential mediators of PCP signaling might have broader implications for other cell types, ciliary disease, and asymmetric cell division. DOI: http://dx.doi.org/10.7554/eLife.03842.001 PMID:25296022

  5. Regulation of a Spindle Positioning Factor at Kinetochores by SUMO-Targeted Ubiquitin Ligases.

    PubMed

    Schweiggert, Jörg; Stevermann, Lea; Panigada, Davide; Kammerer, Daniel; Liakopoulos, Dimitris

    2016-02-22

    Correct function of the mitotic spindle requires balanced interplay of kinetochore and astral microtubules that mediate chromosome segregation and spindle positioning, respectively. Errors therein can cause severe defects ranging from aneuploidy to developmental disorders. Here, we describe a protein degradation pathway that functionally links astral microtubules to kinetochores via regulation of a microtubule-associated factor. We show that the yeast spindle positioning protein Kar9 localizes not only to astral but also to kinetochore microtubules, where it becomes targeted for proteasomal degradation by the SUMO-targeted ubiquitin ligases (STUbLs) Slx5-Slx8. Intriguingly, this process does not depend on preceding sumoylation of Kar9 but rather requires SUMO-dependent recruitment of STUbLs to kinetochores. Failure to degrade Kar9 leads to defects in both chromosome segregation and spindle positioning. We propose that kinetochores serve as platforms to recruit STUbLs in a SUMO-dependent manner in order to ensure correct spindle function by regulating levels of microtubule-associated proteins. PMID:26906737

  6. microRNAs are differentially regulated between MDM2-positive and negative malignant pleural mesothelioma

    PubMed Central

    Walter, Robert Fred Henry; Vollbrecht, Claudia; Werner, Robert; Wohlschlaeger, Jeremias; Christoph, Daniel Christian; Schmid, Kurt Werner; Mairinger, Fabian Dominik

    2016-01-01

    Background Malignant pleural mesothelioma (MPM) is a highly aggressive tumour first-line treated with a combination of cisplatin and pemetrexed. MDM2 and P14/ARF (CDKN2A) are upstream regulators of TP53 and may contribute to its inactivation. In the present study, we now aimed to define the impact of miRNA expression on this mechanism. Material and Methods 24 formalin-fixed paraffin-embedded (FFPE) tumour specimens were used for miRNA expression analysis of the 800 most important miRNAs using the nCounter technique (NanoString). Significantly deregulated miRNAs were identified before a KEGG-pathway analysis was performed. Results 17 miRNAs regulating TP53, 18 miRNAs regulating MDM2, and 11 miRNAs directly regulating CDKN2A are significantly downregulated in MDM2-expressing mesotheliomas. TP53 is downregulated in MDM2-negative tumours through miRNAs with a miSVR prediction score of 11.67, RB1 with a prediction score of 8.02, MDM2 with a prediction score of 4.50 and CDKN2A with a prediction score of 1.27. Conclusion MDM2 expression seems to impact miRNA expression levels in MPM. Especially, miRNAs involved in TP53-signaling are strongly decreased in MDM2-positive mesotheliomas. A better understanding of its tumour biology may open the chance for new therapeutic approaches and thereby augment patients' outcome. PMID:26918730

  7. Positive regulation of c-Myc by cohesin is direct, and evolutionarily conserved

    PubMed Central

    Rhodes, Jenny M.; Bentley, Fiona K.; Print, Cristin G.; Dorsett, Dale; Misulovin, Ziva; Dickinson, Emma J.; Crosier, Kathryn E.; Crosier, Philip S.; Horsfield, Julia A.

    2010-01-01

    Contact between sister chromatids from S phase to anaphase depends on cohesin, a large multi-subunit protein complex. Mutations in sister chromatid cohesion proteins underlie the human developmental condition, Cornelia de Lange Syndrome. Roles for cohesin in regulating gene expression, sometimes in combination with CCCTC-binding factor (CTCF), have emerged. We analyzed zebrafish embryos null for cohesin subunit rad21 using microarrays to determine global effects of cohesin on gene expression during embryogenesis. This identified Rad21-associated gene networks that included myca (zebrafish c-myc), p53 and mdm2. In zebrafish, cohesin binds to the transcription start sites of p53 and mdm2, and depletion of either Rad21 or CTCF increased their transcription. In contrast, myca expression was strongly downregulated upon loss of Rad21 while depletion of CTCF had little effect. Depletion of Rad21 or the cohesin-loading factor Nipped-B in Drosophila cells also reduced expression of myc and Myc target genes. Cohesin bound the transcription start site plus an upstream predicted CTCF binding site at zebrafish myca. Binding and positive regulation of the c-Myc gene by cohesin is conserved through evolution, indicating this regulation is likely to be direct. The exact mechanism of regulation is unknown, but local changes in histone modification associated with transcription repression at the myca gene were observed in rad21 mutants. PMID:20553708

  8. S-Nitrosylation Positively Regulates Ascorbate Peroxidase Activity during Plant Stress Responses1

    PubMed Central

    Yang, Huanjie; Mu, Jinye; Chen, Lichao; Feng, Jian; Hu, Jiliang; Li, Lei; Zhou, Jian-Min; Zuo, Jianru

    2015-01-01

    Nitric oxide (NO) and reactive oxygen species (ROS) are two classes of key signaling molecules involved in various developmental processes and stress responses in plants. The burst of NO and ROS triggered by various stimuli activates downstream signaling pathways to cope with abiotic and biotic stresses. Emerging evidence suggests that the interplay of NO and ROS plays a critical role in regulating stress responses. However, the underpinning molecular mechanism remains poorly understood. Here, we show that NO positively regulates the activity of the Arabidopsis (Arabidopsis thaliana) cytosolic ascorbate peroxidase1 (APX1). We found that S-nitrosylation of APX1 at cysteine (Cys)-32 enhances its enzymatic activity of scavenging hydrogen peroxide, leading to the increased resistance to oxidative stress, whereas a substitution mutation at Cys-32 causes the reduction of ascorbate peroxidase activity and abolishes its responsiveness to the NO-enhanced enzymatic activity. Moreover, S-nitrosylation of APX1 at Cys-32 also plays an important role in regulating immune responses. These findings illustrate a unique mechanism by which NO regulates hydrogen peroxide homeostasis in plants, thereby establishing a molecular link between NO and ROS signaling pathways. PMID:25667317

  9. msaABCR operon positively regulates biofilm development by repressing proteases and autolysis in Staphylococcus aureus

    PubMed Central

    Sahukhal, Gyan S.; Batte, Justin L.; Elasri, Mohamed O.

    2015-01-01

    Staphylococcus aureus is an important human pathogen that causes nosocomial and community-acquired infections. One of the most important aspects of staphylococcal infections is biofilm development within the host, which renders the bacterium resistant to the host's immune response and antimicrobial agents. Biofilm development is very complex and involves several regulators that ensure cell survival on surfaces within the extracellular polymeric matrix. Previously, we identified the msaABCR operon as an additional positive regulator of biofilm formation. In this study, we define the regulatory pathway by which msaABCR controls biofilm formation. We demonstrate that the msaABCR operon is a negative regulator of proteases. The control of protease production mediates the processing of the major autolysin, Atl, and thus regulates the rate of autolysis. In the absence of the msaABCR operon, Atl is processed by proteases at a high rate, leading to increased cell death and a defect in biofilm maturation. We conclude that the msaABCR operon plays a key role in maintaining the balance between autolysis and growth within the staphylococcal biofilm. PMID:25724778

  10. Regulating and facilitating: the role of emotional intelligence in maintaining and using positive affect for creativity.

    PubMed

    Parke, Michael R; Seo, Myeong-Gu; Sherf, Elad N

    2015-05-01

    Although past research has identified the effects of emotional intelligence on numerous employee outcomes, the relationship between emotional intelligence and creativity has not been well established. We draw upon affective information processing theory to explain how two facets of emotional intelligence-emotion regulation and emotion facilitation-shape employee creativity. Specifically, we propose that emotion regulation ability enables employees to maintain higher positive affect (PA) when faced with unique knowledge processing requirements, while emotion facilitation ability enables employees to use their PA to enhance their creativity. We find support for our hypotheses using a multimethod (ability test, experience sampling, survey) and multisource (archival, self-reported, supervisor-reported) research design of early career managers across a wide range of jobs. PMID:25528247

  11. Positive Regulation of TRAF6-Dependent Innate Immune Responses by Protein Phosphatase PP1-γ

    PubMed Central

    Chiang, Chih-yuan; Nguyen, Quy T.; Maestre, Ana M.; Mulder, Lubbertus C. F.; Secundino, Ismael; De Jesus, Paul D.; König, Renate; Simon, Viviana; Nizet, Victor; MacLeod, Graham; Varmuza, Susannah; Fernandez-Sesma, Ana; Chanda, Sumit K.

    2014-01-01

    Innate immune sensors such as Toll-like receptors (TLRs) differentially utilize adaptor proteins and additional molecular mediators to ensure robust and precise immune responses to pathogen challenge. Through a gain-of-function genetic screen, we identified the gamma catalytic subunit of protein phosphatase 1 (PP1-γ) as a positive regulator of MyD88-dependent proinflammatory innate immune activation. PP1-γ physically interacts with the E3 ubiquitin ligase TRAF6, and enhances the activity of TRAF6 towards itself and substrates such as IKKγ, whereas enzymatically inactive PP1-γ represses these events. Importantly, these activities were found to be critical for cellular innate responses to pathogen challenge and microbial clearance in both mouse macrophages and human monocyte lines. These data indicate that PP1-γ phosphatase activity regulates overall TRAF6 E3 ubiquitin ligase function and promotes NF-κB-mediated innate signaling responses. PMID:24586659

  12. OsGF14e positively regulates panicle blast resistance in rice.

    PubMed

    Liu, Qing; Yang, Jianyuan; Zhang, Shaohong; Zhao, Junliang; Feng, Aiqing; Yang, Tifeng; Wang, Xiaofei; Mao, Xingxue; Dong, Jingfang; Zhu, Xiaoyuan; Leung, Hei; Leach, Jan E; Liu, Bin

    2016-02-26

    Though GF14e has been reported to negatively regulate bacterial blight and sheath blight resistance in rice, its effect on panicle blast, the most destructive disease in rice is still unknown. In the present study, we identified that GF14e was highly expressed in panicles and was induced in panicles infected by blast pathogen. Overexpression of GF14e enhances resistance to panicle blast whereas silencing GF14e results in increased susceptibility to panicle blast, suggesting that GF14e plays a positive role in quantitative panicle blast resistance in rice. Our results also demonstrate that GF14e is regulated by WRKY71 and GF14e-mediated panicle blast resistance is related to activation of SA-dependent pathway and suppression of JA-dependent pathway. The functional confirmation of GF14e in panicle blast resistance makes it to be a promising target in molecular rice breeding. PMID:26851365

  13. Crystallographic characterization of the DIX domain of the Wnt signalling positive regulator Ccd1

    PubMed Central

    Terawaki, Shin-ichi; Yano, Koumei; Katsutani, Takuya; Shiomi, Kensuke; Keino-Masu, Kazuko; Masu, Masayuki; Shomura, Yasuhito; Komori, Hirofumi; Shibata, Naoki; Higuchi, Yoshiki

    2011-01-01

    Coiled-coil DIX1 (Ccd1) is a positive regulator that activates the canonical Wnt signalling pathway by inhibiting the degradation of the key signal transducer β-­catenin. The C-terminal DIX domain of Ccd1 plays an important role in the regulation of signal transduction through homo-oligomerization and protein complex formation with other DIX domain-containing proteins, i.e. axin and dishevelled proteins. Here, the expression, purification, crystallization and X-ray data collection of the Ccd1 DIX domain are reported. The crystals of the Ccd1 DIX domain belonged to space group P212121, with unit-cell parameters a = 72.9, b = 75.7, c = 125.6 Å. An X-ray diffraction data set was collected at 3.0 Å resolution. PMID:21795788

  14. TCP2 positively regulates HY5/HYH and photomorphogenesis in Arabidopsis

    PubMed Central

    He, Zhimin; Zhao, Xiaoying; Kong, Fanna; Zuo, Zecheng; Liu, Xuanming

    2016-01-01

    Light regulates plant growth and development via multiple photoreceptors including phytochromes and cryptochromes. Although the functions of photoreceptors have been studied extensively, questions remain regarding the involvement of cryptochromes in photomorphogenesis. In this study, we identified a protein, TEOSINTE-LIKE1, CYCLOIDEA, and PROLIFERATING CELL FACTOR 2 (TCP2), which interacts with the cryptochrome 1 (CRY1) protein in yeast and plant cells via the N-terminal domains of both proteins. Transgenic plants overexpressing TCP2 displayed a light-dependent short hypocotyl phenotype, especially in response to blue light. Moreover, light affected TCP2 expression in a wavelength-dependent manner and TCP2 positively regulates mRNA expression of HYH and HY5. These results support the hypothesis that TCP2 is a transcription activator which acts downstream of multiple photoreceptors, including CRY1. PMID:26596765

  15. Regulation of dynein localization and centrosome positioning by Lis-1 and asunder during Drosophila spermatogenesis

    PubMed Central

    Sitaram, Poojitha; Anderson, Michael A.; Jodoin, Jeanne N.; Lee, Ethan; Lee, Laura A.

    2012-01-01

    Dynein, a microtubule motor complex, plays crucial roles in cell-cycle progression in many systems. The LIS1 accessory protein directly binds dynein, although its precise role in regulating dynein remains unclear. Mutation of human LIS1 causes lissencephaly, a developmental brain disorder. To gain insight into the in vivo functions of LIS1, we characterized a male-sterile allele of the Drosophila homolog of human LIS1. We found that centrosomes do not properly detach from the cell cortex at the onset of meiosis in most Lis-1 spermatocytes; centrosomes that do break cortical associations fail to attach to the nucleus. In Lis-1 spermatids, we observed loss of attachments between the nucleus, basal body and mitochondria. The localization pattern of LIS-1 protein throughout Drosophila spermatogenesis mirrors that of dynein. We show that dynein recruitment to the nuclear surface and spindle poles is severely reduced in Lis-1 male germ cells. We propose that Lis-1 spermatogenesis phenotypes are due to loss of dynein regulation, as we observed similar phenotypes in flies null for Tctex-1, a dynein light chain. We have previously identified asunder (asun) as another regulator of dynein localization and centrosome positioning during Drosophila spermatogenesis. We now report that Lis-1 is a strong dominant enhancer of asun and that localization of LIS-1 in male germ cells is ASUN dependent. We found that Drosophila LIS-1 and ASUN colocalize and coimmunoprecipitate from transfected cells, suggesting that they function within a common complex. We present a model in which Lis-1 and asun cooperate to regulate dynein localization and centrosome positioning during Drosophila spermatogenesis. PMID:22764052

  16. [Position of French transfusion operator in the regulation of territorial care in a changing context].

    PubMed

    Thibert, J-B

    2015-01-01

    Since the first law regarding the French transfusion, the public service of blood transfusion has always evolved. Today, different factors are changing: consequences of combination of French laws and European rules, new regulations and required levels of blood products. Moreover, those changes lead us to look at the position of the EFS in his health's territory which is actually changing too. The study of the context and actual laws could draw a first picture of the opportunities available for the EFS to face those new challenges. PMID:26603288

  17. Clathrin regulates centrosome positioning by promoting acto-myosin cortical tension in C. elegans embryos.

    PubMed

    Spiró, Zoltán; Thyagarajan, Kalyani; De Simone, Alessandro; Träger, Sylvain; Afshar, Katayoun; Gönczy, Pierre

    2014-07-01

    Regulation of centrosome and spindle positioning is crucial for spatial cell division control. The one-cell Caenorhabditis elegans embryo has proven attractive for dissecting the mechanisms underlying centrosome and spindle positioning in a metazoan organism. Previous work revealed that these processes rely on an evolutionarily conserved force generator complex located at the cell cortex. This complex anchors the motor protein dynein, thus allowing cortical pulling forces to be exerted on astral microtubules emanating from microtubule organizing centers (MTOCs). Here, we report that the clathrin heavy chain CHC-1 negatively regulates pulling forces acting on centrosomes during interphase and on spindle poles during mitosis in one-cell C. elegans embryos. We establish a similar role for the cytokinesis/apoptosis/RNA-binding protein CAR-1 and uncover that CAR-1 is needed to maintain proper levels of CHC-1. We demonstrate that CHC-1 is necessary for normal organization of the cortical acto-myosin network and for full cortical tension. Furthermore, we establish that the centrosome positioning phenotype of embryos depleted of CHC-1 is alleviated by stabilizing the acto-myosin network. Conversely, we demonstrate that slight perturbations of the acto-myosin network in otherwise wild-type embryos results in excess centrosome movements resembling those in chc-1(RNAi) embryos. We developed a 2D computational model to simulate cortical rigidity-dependent pulling forces, which recapitulates the experimental data and further demonstrates that excess centrosome movements are produced at medium cortical rigidity values. Overall, our findings lead us to propose that clathrin plays a critical role in centrosome positioning by promoting acto-myosin cortical tension. PMID:24961801

  18. Patterned Contractile Forces Promote Epidermal Spreading and Regulate Segment Positioning during Drosophila Head Involution.

    PubMed

    Czerniak, Natalia Dorota; Dierkes, Kai; D'Angelo, Arturo; Colombelli, Julien; Solon, Jérôme

    2016-07-25

    Epithelial spreading is a fundamental mode of tissue rearrangement occurring during animal development and wound closure. It has been associated either with the collective migration of cells [1, 2] or with actomyosin-generated forces acting at the leading edge (LE) and pulling the epithelial tissue [3, 4]. During the process of Drosophila head involution (HI), the epidermis spreads anteriorly to envelope the head tissues and fully cover the embryo [5]. This results in epidermal segments of equal width that will give rise to the different organs of the fly [6]. Here we perform a quantitative analysis of tissue spreading during HI. Combining high-resolution live microscopy with laser microsurgery and genetic perturbations, we show that epidermal movement is in part, but not solely, driven by a contractile actomyosin cable at the LE. Additional driving forces are generated within each segment by a gradient of actomyosin-based circumferential tension. Interfering with Hedgehog (Hh) signaling can modulate this gradient, thus suggesting the involvement of polarity genes in the regulation of HI. In particular, we show that disruption of these contractile forces alters segment widths and leads to a mispositioning of segments. Within the framework of a physical description, we confirm that given the geometry of the embryo, a patterned profile of active circumferential tensions can indeed generate propelling forces and control final segment position. Our study thus unravels a mechanism by which patterned tensile forces can regulate spreading and positioning of epithelial tissues. PMID:27397891

  19. Positive feedback regulation between IL10 and EGFR promotes lung cancer formation.

    PubMed

    Hsu, Tsung-I; Wang, Yi-Chang; Hung, Chia-Yang; Yu, Chun-Hui; Su, Wu-Chou; Chang, Wen-Chang; Hung, Jan-Jong

    2016-04-12

    The role of IL10 in the tumorigenesis of various cancer types is still controversial. Here, we found that increased IL10 levels are correlated with a poor prognosis in lung cancer patients. Moreover, IL10 levels were significantly increased in the lungs and serum of EGFRL858R- and Kras4bG12D-induced lung cancer mice, indicating that IL10 might facilitate lung cancer tumorigenesis. IL10 knockout in EGFRL858R and Kras4bG12D mice inhibited the development of lung tumors and decreased the levels of infiltrating M2 macrophages and tumor-promoting Treg lymphocytes. We also showed that EGF increases IL10 expression by enhancing IL10 mRNA stability, and IL10 subsequently activates JAK1/STAT3, Src, PI3K/Akt, and Erk signaling pathways. Interestingly, the IL10-induced recruitment of phosphorylated Src was critical for inducing EGFR through the activation of the JAK1/STAT3 pathway, suggesting that Src and JAK1 positively regulate each other to enhance STAT3 activity. Doxycycline-induced EGFRL858R mice treated with gefitinib and anti-IL10 antibodies exhibited poor tumor formation. In conclusion, IL10 and EGFR regulate each other through positive feedback, which leads to lung cancer formation. PMID:26956044

  20. Positioning advanced practice registered nurses for health care reform: consensus on APRN regulation.

    PubMed

    Stanley, Joan M; Werner, Kathryn E; Apple, Kathy

    2009-01-01

    Advanced practice registered nurses (APRNs) have positioned themselves to serve an integral role in national health care reform. This article addresses both the policy and the process to develop this policy that has placed them in a strategic position. A successful transformation of the nation's health system will require utilization of all clinicians, particularly primary care providers, to the full extent of their education and scope of practice. APRNs are highly qualified clinicians who provide cost-effective, accessible, patient-centered care and have the education to provide the range of services at the heart of the reform movement, including care coordination, chronic care management, and wellness and preventive care. The APRN community faces many challenges amidst the opportunities of health reform. However, the APRN community's triumph in reaching consensus on APRN regulation signifies a cohesive approach to overcoming the obstacles. The consensus model for APRN regulation, endorsed by 44 national nursing organizations, will serve as a beacon for nursing, as well as a guidepost for consumers and policymakers, on titling, education, certification, accreditation, and licensing for all four APRN roles. PMID:19942200

  1. Reciprocal positive regulation between TRPV6 and NUMB in PTEN-deficient prostate cancer cells

    SciTech Connect

    Kim, Sung-Young; Hong, Chansik; Wie, Jinhong; Kim, Euiyong; Kim, Byung Joo; Ha, Kotdaji; Cho, Nam-Hyuk; Kim, In-Gyu; Jeon, Ju-Hong; So, Insuk

    2014-04-25

    Highlights: • TRPV6 interacts with tumor suppressor proteins. • Numb has a selective effect on TRPV6, depending on the prostate cancer cell line. • PTEN is a novel regulator of TRPV6–Numb complex. - Abstract: Calcium acts as a second messenger and plays a crucial role in signaling pathways involved in cell proliferation. Recently, calcium channels related to calcium influx into the cytosol of epithelial cells have attracted attention as a cancer therapy target. Of these calcium channels, TRPV6 is overexpressed in prostate cancer and is considered an important molecule in the process of metastasis. However, its exact role and mechanism is unclear. NUMB, well-known tumor suppressor gene, is a novel interacting partner of TRPV6. We show that NUMB and TRPV6 have a reciprocal positive regulatory relationship in PC-3 cells. We repeated this experiment in two other prostate cancer cell lines, DU145 and LNCaP. Interestingly, there were no significant changes in TRPV6 expression following NUMB knockdown in DU145. We revealed that the presence or absence of PTEN was the cause of NUMB–TRPV6 function. Loss of PTEN caused a positive correlation of TRPV6–NUMB expression. Collectively, we determined that PTEN is a novel interacting partner of TRPV6 and NUMB. These results demonstrated a novel relationship of NUMB–TRPV6 in prostate cancer cells, and show that PTEN is a novel regulator of this complex.

  2. Positive feedback regulation between IL10 and EGFR promotes lung cancer formation

    PubMed Central

    Hsu, Tsung-I; Wang, Yi-Chang; Hung, Chia-Yang; Yu, Chun-Hui; Su, Wu-Chou; Chang, Wen-Chang; Hung, Jan-Jong

    2016-01-01

    The role of IL10 in the tumorigenesis of various cancer types is still controversial. Here, we found that increased IL10 levels are correlated with a poor prognosis in lung cancer patients. Moreover, IL10 levels were significantly increased in the lungs and serum of EGFRL858R- and Kras4bG12D-induced lung cancer mice, indicating that IL10 might facilitate lung cancer tumorigenesis. IL10 knockout in EGFRL858R and Kras4bG12D mice inhibited the development of lung tumors and decreased the levels of infiltrating M2 macrophages and tumor-promoting Treg lymphocytes. We also showed that EGF increases IL10 expression by enhancing IL10 mRNA stability, and IL10 subsequently activates JAK1/STAT3, Src, PI3K/Akt, and Erk signaling pathways. Interestingly, the IL10-induced recruitment of phosphorylated Src was critical for inducing EGFR through the activation of the JAK1/STAT3 pathway, suggesting that Src and JAK1 positively regulate each other to enhance STAT3 activity. Doxycycline-induced EGFRL858R mice treated with gefitinib and anti-IL10 antibodies exhibited poor tumor formation. In conclusion, IL10 and EGFR regulate each other through positive feedback, which leads to lung cancer formation. PMID:26956044

  3. Ethylene positively regulates cold tolerance in grapevine by modulating the expression of ETHYLENE RESPONSE FACTOR 057

    PubMed Central

    Sun, Xiaoming; Zhao, Tingting; Gan, Shuheng; Ren, Xiaodie; Fang, Linchuan; Karungo, Sospeter Karanja; Wang, Yi; Chen, Liang; Li, Shaohua; Xin, Haiping

    2016-01-01

    Ethylene (ET) is a gaseous plant hormone that plays essential roles in biotic and abiotic stress responses in plants. However, the role of ET in cold tolerance varies in different species. This study revealed that low temperature promotes the release of ET in grapevine. The treatment of exogenous 1-aminocyclopropane-1-carboxylate increased the cold tolerance of grapevine. By contrast, the application of the ET biosynthesis inhibitor aminoethoxyvinylglycine reduced the cold tolerance of grapevine. This finding suggested that ET positively affected cold stress responses in grapevine. The expression of VaERF057, an ET signaling downstream gene, was strongly induced by low temperature. The overexpression of VaERF057 also enhanced the cold tolerance of Arabidopsis. Under cold treatment, malondialdehyde content was lower and superoxide dismutase, peroxidase, and catalase activities were higher in transgenic lines than in wild-type plants. RNA-Seq results showed that 32 stress-related genes, such as CBF1-3, were upregulated in VaERF057-overexpressing transgenic line. Yeast one-hybrid results further demonstrated that VaERF057 specifically binds to GCC-box and DRE motifs. Thus, VaERF057 may directly regulate the expression of its target stress-responsive genes by interacting with a GCC-box or a DRE element. Our work confirmed that ET positively regulates cold tolerance in grapevine by modulating the expression of VaERF057. PMID:27039848

  4. Ethylene positively regulates cold tolerance in grapevine by modulating the expression of ETHYLENE RESPONSE FACTOR 057.

    PubMed

    Sun, Xiaoming; Zhao, Tingting; Gan, Shuheng; Ren, Xiaodie; Fang, Linchuan; Karungo, Sospeter Karanja; Wang, Yi; Chen, Liang; Li, Shaohua; Xin, Haiping

    2016-01-01

    Ethylene (ET) is a gaseous plant hormone that plays essential roles in biotic and abiotic stress responses in plants. However, the role of ET in cold tolerance varies in different species. This study revealed that low temperature promotes the release of ET in grapevine. The treatment of exogenous 1-aminocyclopropane-1-carboxylate increased the cold tolerance of grapevine. By contrast, the application of the ET biosynthesis inhibitor aminoethoxyvinylglycine reduced the cold tolerance of grapevine. This finding suggested that ET positively affected cold stress responses in grapevine. The expression of VaERF057, an ET signaling downstream gene, was strongly induced by low temperature. The overexpression of VaERF057 also enhanced the cold tolerance of Arabidopsis. Under cold treatment, malondialdehyde content was lower and superoxide dismutase, peroxidase, and catalase activities were higher in transgenic lines than in wild-type plants. RNA-Seq results showed that 32 stress-related genes, such as CBF1-3, were upregulated in VaERF057-overexpressing transgenic line. Yeast one-hybrid results further demonstrated that VaERF057 specifically binds to GCC-box and DRE motifs. Thus, VaERF057 may directly regulate the expression of its target stress-responsive genes by interacting with a GCC-box or a DRE element. Our work confirmed that ET positively regulates cold tolerance in grapevine by modulating the expression of VaERF057. PMID:27039848

  5. Position-specific binding of FUS to nascent RNA regulates mRNA length

    PubMed Central

    Masuda, Akio; Takeda, Jun-ichi; Okuno, Tatsuya; Okamoto, Takaaki; Ohkawara, Bisei; Ito, Mikako; Ishigaki, Shinsuke; Sobue, Gen

    2015-01-01

    More than half of all human genes produce prematurely terminated polyadenylated short mRNAs. However, the underlying mechanisms remain largely elusive. CLIP-seq (cross-linking immunoprecipitation [CLIP] combined with deep sequencing) of FUS (fused in sarcoma) in neuronal cells showed that FUS is frequently clustered around an alternative polyadenylation (APA) site of nascent RNA. ChIP-seq (chromatin immunoprecipitation [ChIP] combined with deep sequencing) of RNA polymerase II (RNAP II) demonstrated that FUS stalls RNAP II and prematurely terminates transcription. When an APA site is located upstream of an FUS cluster, FUS enhances polyadenylation by recruiting CPSF160 and up-regulates the alternative short transcript. In contrast, when an APA site is located downstream from an FUS cluster, polyadenylation is not activated, and the RNAP II-suppressing effect of FUS leads to down-regulation of the alternative short transcript. CAGE-seq (cap analysis of gene expression [CAGE] combined with deep sequencing) and PolyA-seq (a strand-specific and quantitative method for high-throughput sequencing of 3' ends of polyadenylated transcripts) revealed that position-specific regulation of mRNA lengths by FUS is operational in two-thirds of transcripts in neuronal cells, with enrichment in genes involved in synaptic activities. PMID:25995189

  6. eEF1Bγ is a positive regulator of NF-кB signaling pathway.

    PubMed

    Liu, Dong; Sheng, Chunjie; Gao, Shijuan; Jiang, Wei; Li, Jiandong; Yao, Chen; Chen, Huiming; Wu, Jiaoxiang; Chen, Shuai; Huang, Wenlin

    2014-04-01

    Mitochondrial antiviral-signaling protein (MAVS), as a critical adaptor of RIG-I signaling, bridges viral RNA recognition and downstream signal activation. However, the regulating mechanisms of MAVS are not well understood. In this study, we demonstrated that eukaryotic elongation factor 1B gamma (eEF1Bγ) activates NF-кB signaling pathway through targeting MAVS. GST-pull down and mass spectrometric analysis suggested that eEF1Bγ binds to the CARD domain of MAVS. The interaction and mitochondrial colocalization of eEF1Bγ and MAVS were further verified by co-immunoprecipitation (co-IP) and immunofluorescence microscopy assays. The dual-luciferase assays showed that ectopic expression of eEF1Bγ significantly promotes the activities of transcription factor NF-кB and promoters of downstream proinflammatory cytokines Interleukin-8 (IL-8) and Interleukin-6 (IL-6). eEF1Bγ increases the abundance of MAVS by promoting its K63-linked polyubiquitination and attenuating its K48-linked polyubiquitination. Besides, proline-rich (Pro) region and CARD domain of MAVS are indispensable for the process of eEF1Bγ mediated ubiquitination. Collectively, these results demonstrated that eEF1Bγ functions as a positive regulator of NF-кB signal by targeting MAVS for activation, which provides a new regulating mechanism of antiviral responses. PMID:24613846

  7. p73: a Positive or Negative Regulator of Angiogenesis, or Both?

    PubMed

    Sabapathy, Kanaga

    2016-03-01

    The role of p73, the homologue of the tumor suppressor p53, in regulating angiogenesis has recently been extensively investigated, resulting in the publication of five articles. Of these, two studies suggested a suppressive role, while the others implied a stimulatory role for the p73 isoforms in regulating angiogenesis. A negative role for TAp73, the full-length form that is often associated with tumor suppression, in blood vessel formation, is consistent with its general attributes and was proposed to be effected indirectly through the degradation of hypoxia-inducible factor 1α (HIF1-α), the master angiogenic regulator. In contrast, a positive role for TAp73 coincides with its recently understood role in supporting cellular survival and thus tumorigenesis, consistent with TAp73 being not-mutated but rather often overexpressed in clinical contexts. In the latter case, TAp73 expression was induced by hypoxia via HIF1-α, and it appears to directly promote angiogenic target gene activation and blood vessel formation independent of HIF1-α. This mini review will provide an overview of these seemingly opposite recent findings as well as earlier data, which collectively establish the definite possibility that TAp73 is indeed capable of both promoting and inhibiting angiogenesis, depending on the cellular context. PMID:26711266

  8. Phosphorylation acts positively and negatively to regulate MRTF-A subcellular localisation and activity.

    PubMed

    Panayiotou, Richard; Miralles, Francesc; Pawlowski, Rafal; Diring, Jessica; Flynn, Helen R; Skehel, Mark; Treisman, Richard

    2016-01-01

    The myocardin-related transcription factors (MRTF-A and MRTF-B) regulate cytoskeletal genes through their partner transcription factor SRF. The MRTFs bind G-actin, and signal-regulated changes in cellular G-actin concentration control their nuclear accumulation. The MRTFs also undergo Rho- and ERK-dependent phosphorylation, but the function of MRTF phosphorylation, and the elements and signals involved in MRTF-A nuclear export are largely unexplored. We show that Rho-dependent MRTF-A phosphorylation reflects relief from an inhibitory function of nuclear actin. We map multiple sites of serum-induced phosphorylation, most of which are S/T-P motifs and show that S/T-P phosphorylation is required for transcriptional activation. ERK-mediated S98 phosphorylation inhibits assembly of G-actin complexes on the MRTF-A regulatory RPEL domain, promoting nuclear import. In contrast, S33 phosphorylation potentiates the activity of an autonomous Crm1-dependent N-terminal NES, which cooperates with five other NES elements to exclude MRTF-A from the nucleus. Phosphorylation thus plays positive and negative roles in the regulation of MRTF-A. PMID:27304076

  9. Phosphorylation acts positively and negatively to regulate MRTF-A subcellular localisation and activity

    PubMed Central

    Panayiotou, Richard; Miralles, Francesc; Pawlowski, Rafal; Diring, Jessica; Flynn, Helen R; Skehel, Mark; Treisman, Richard

    2016-01-01

    The myocardin-related transcription factors (MRTF-A and MRTF-B) regulate cytoskeletal genes through their partner transcription factor SRF. The MRTFs bind G-actin, and signal-regulated changes in cellular G-actin concentration control their nuclear accumulation. The MRTFs also undergo Rho- and ERK-dependent phosphorylation, but the function of MRTF phosphorylation, and the elements and signals involved in MRTF-A nuclear export are largely unexplored. We show that Rho-dependent MRTF-A phosphorylation reflects relief from an inhibitory function of nuclear actin. We map multiple sites of serum-induced phosphorylation, most of which are S/T-P motifs and show that S/T-P phosphorylation is required for transcriptional activation. ERK-mediated S98 phosphorylation inhibits assembly of G-actin complexes on the MRTF-A regulatory RPEL domain, promoting nuclear import. In contrast, S33 phosphorylation potentiates the activity of an autonomous Crm1-dependent N-terminal NES, which cooperates with five other NES elements to exclude MRTF-A from the nucleus. Phosphorylation thus plays positive and negative roles in the regulation of MRTF-A. DOI: http://dx.doi.org/10.7554/eLife.15460.001 PMID:27304076

  10. p73: a Positive or Negative Regulator of Angiogenesis, or Both?

    PubMed Central

    2015-01-01

    The role of p73, the homologue of the tumor suppressor p53, in regulating angiogenesis has recently been extensively investigated, resulting in the publication of five articles. Of these, two studies suggested a suppressive role, while the others implied a stimulatory role for the p73 isoforms in regulating angiogenesis. A negative role for TAp73, the full-length form that is often associated with tumor suppression, in blood vessel formation, is consistent with its general attributes and was proposed to be effected indirectly through the degradation of hypoxia-inducible factor 1α (HIF1-α), the master angiogenic regulator. In contrast, a positive role for TAp73 coincides with its recently understood role in supporting cellular survival and thus tumorigenesis, consistent with TAp73 being not-mutated but rather often overexpressed in clinical contexts. In the latter case, TAp73 expression was induced by hypoxia via HIF1-α, and it appears to directly promote angiogenic target gene activation and blood vessel formation independent of HIF1-α. This mini review will provide an overview of these seemingly opposite recent findings as well as earlier data, which collectively establish the definite possibility that TAp73 is indeed capable of both promoting and inhibiting angiogenesis, depending on the cellular context. PMID:26711266

  11. Dab2IP Regulates Neuronal Positioning, Rap1 Activity and Integrin Signaling in the Developing Cortex.

    PubMed

    Qiao, Shuhong; Homayouni, Ramin

    2015-01-01

    Dab2IP (DOC-2/DAB2 interacting protein) is a GTPase-activating protein which is involved in various aspects of brain development in addition to its roles in tumor formation and apoptosis in other systems. In this study, we carefully examined the expression profile of Dab2IP and investigated its physiological role during brain development using a Dab2IP-knockdown (KD) mouse model created by retroviral insertion of a LacZ-encoding gene-trapping cassette. LacZ staining revealed that Dab2IP is expressed in the ventricular zone as well as the cortical plate and the intermediate zone. Immunohistochemical analysis showed that Dab2IP protein is localized in the leading process and proximal cytoplasmic regions of migrating neurons in the intermediate zone. Bromodeoxyuridine birth dating experiments in combination with immunohistochemical analysis using layer-specific markers showed that Dab2IP is important for proper positioning of a subset of layer II-IV neurons in the developing cortex. Notably, neuronal migration was not completely disrupted in the cerebral cortex of Dab2IP-KD mice and disruption of migration was not strictly layer specific. Previously, we found that Dab2IP regulates multipolar transition in cortical neurons. Others have shown that Rap1 regulates the transition from multipolar to bipolar morphology in migrating postmitotic neurons through N-cadherin signaling and somal translocation in the superficial layer of the cortical plate through integrin signaling. Therefore, we examined whether Rap1 and integrin signaling were affected in Dab2IP-KD brains. We found that Dab2IP-KD resulted in higher levels of activated Rap1 and integrin in the developing cortex. Taken together, our results suggest that Dab2IP plays an important role in the migration and positioning of a subpopulation of later-born (layers II-IV) neurons, likely through the regulation of Rap1 and integrin signaling. PMID:25721469

  12. PAR-4 and anillin regulate myosin to coordinate spindle and furrow position during asymmetric division

    PubMed Central

    Uhart, Perrine; Tassan, Jean-Pierre; Michaux, Grégoire

    2015-01-01

    During asymmetric cell division, the mitotic spindle and polarized myosin can both determine the position of the cytokinetic furrow. However, how cells coordinate signals from the spindle and myosin to ensure that cleavage occurs through the spindle midzone is unknown. Here, we identify a novel pathway that is essential to inhibit myosin and coordinate furrow and spindle positions during asymmetric division. In Caenorhabditis elegans one-cell embryos, myosin localizes at the anterior cortex whereas the mitotic spindle localizes toward the posterior. We find that PAR-4/LKB1 impinges on myosin via two pathways, an anillin-dependent pathway that also responds to the cullin CUL-5 and an anillin-independent pathway involving the kinase PIG-1/MELK. In the absence of both PIG-1/MELK and the anillin ANI-1, myosin accumulates at the anterior cortex and induces a strong displacement of the furrow toward the anterior, which can lead to DNA segregation defects. Regulation of asymmetrically localized myosin is thus critical to ensure that furrow and spindle midzone positions coincide throughout cytokinesis. PMID:26416962

  13. PAR-4 and anillin regulate myosin to coordinate spindle and furrow position during asymmetric division.

    PubMed

    Pacquelet, Anne; Uhart, Perrine; Tassan, Jean-Pierre; Michaux, Grégoire

    2015-09-28

    During asymmetric cell division, the mitotic spindle and polarized myosin can both determine the position of the cytokinetic furrow. However, how cells coordinate signals from the spindle and myosin to ensure that cleavage occurs through the spindle midzone is unknown. Here, we identify a novel pathway that is essential to inhibit myosin and coordinate furrow and spindle positions during asymmetric division. In Caenorhabditis elegans one-cell embryos, myosin localizes at the anterior cortex whereas the mitotic spindle localizes toward the posterior. We find that PAR-4/LKB1 impinges on myosin via two pathways, an anillin-dependent pathway that also responds to the cullin CUL-5 and an anillin-independent pathway involving the kinase PIG-1/MELK. In the absence of both PIG-1/MELK and the anillin ANI-1, myosin accumulates at the anterior cortex and induces a strong displacement of the furrow toward the anterior, which can lead to DNA segregation defects. Regulation of asymmetrically localized myosin is thus critical to ensure that furrow and spindle midzone positions coincide throughout cytokinesis. PMID:26416962

  14. CELSR1 Is a Positive Regulator of Endothelial Cell Migration and Angiogenesis.

    PubMed

    Zhan, Yi-Hong; Luo, Qi-Cong; Zhang, Xiao-Rong; Xiao, Nai-An; Lu, Cong-Xia; Yue, Cen; Wang, Ning; Ma, Qi-Lin

    2016-06-01

    Cadherin is an epidermal growth factor and laminin-G seven-pass G-type receptor 1 (CELSR1) is a key component of the noncanonical Wnt/planar cell polarity (PCP) pathway that critically regulates endothelial cell proliferation and angiogenesis. In this study, we examined the biological significance of CELSR1 in endothelial cell migration and angiogenesis. For this, we applied both gain-of-function and loss-of-function approaches. To increase the endogenous expression of CELSR1, we used the transcription activator-like effector (TALE) technology and constructed an artificial TALE-VP64 activator. To knock down the expression of CELSR1, we generated lentivirus containing short hairpin RNA sequences targeting different regions of CELSR1 mRNA. Following up- or down-regulation of CELSR1 in human aortic endothelial cells (HAEC), we assessed in vitro cell proliferation by MTT assay, migration by scratch and transwell migration assays, and angiogenesis by tube formation analysis. We found that CELSR1 was endogenously expressed in human umbilical vein endothelial cells (HUVEC) and HAEC. When focusing on HAEC, we found that upregulating CELSR1 expression significantly promoted cell growth, while knocking down CELSR1 inhibited the growth (p < 0.05). Using both scratch and transwell migration assays, we observed a positive correlation between CELSR1 expression and cell migratory capability. In addition, CELSR1 upregulation led to higher levels of tube formation in HAEC, while downregulating CELSR1 expression decreased tube formation (p < 0.05). Mechanistically, CELSR1-regulated migration and tube formation was mediated through disheveled segment polarity protein 3 (Dvl3). In conclusion, CELSR1 plays an important role in regulating multiple phenotypes of endothelial cells, including proliferation, migration, and formation of capillary-like structures. PMID:27301287

  15. Ly49Q, an ITIM-bearing NK receptor, positively regulates osteoclast differentiation

    SciTech Connect

    Hayashi, Mikihito; Nakashima, Tomoki; Kodama, Tatsuhiko; Makrigiannis, Andrew P.; Toyama-Sorimachi, Noriko; Takayanagi, Hiroshi

    2010-03-12

    Osteoclasts, multinucleated cells that resorb bone, play a key role in bone remodeling. Although immunoreceptor tyrosine-based activation motif (ITAM)-mediated signaling is critical for osteoclast differentiation, the significance of immunoreceptor tyrosine-based inhibitory motif (ITIM) has not been well understood. Here we report the function of Ly49Q, an Ly49 family member possessing an ITIM motif, in osteoclastogenesis. Ly49Q is selectively induced by receptor activator of nuclear factor-{kappa}B (NF-{kappa}B) ligand (RANKL) stimulation in bone marrow-derived monocyte/macrophage precursor cells (BMMs) among the Ly49 family of NK receptors. The knockdown of Ly49Q resulted in a significant reduction in the RANKL-induced formation of tartrate-resistance acid phosphatase (TRAP)-positive multinucleated cells, accompanied by a decreased expression of osteoclast-specific genes such as Nfatc1, Tm7sf4, Oscar, Ctsk, and Acp5. Osteoclastogenesis was also significantly impaired in Ly49Q-deficient cells in vitro. The inhibitory effect of Ly49Q-deficiency may be explained by the finding that Ly49Q competed for the association of Src-homology domain-2 phosphatase-1 (SHP-1) with paired immunoglobulin-like receptor-B (PIR-B), an ITIM-bearing receptor which negatively regulates osteoclast differentiation. Unexpectedly, Ly49Q deficiency did not lead to impaired osteoclast formation in vivo, suggesting the existence of a compensatory mechanism. This study provides an example in which an ITIM-bearing receptor functions as a positive regulator of osteoclast differentiation.

  16. cAMP-response-element-binding protein positively regulates breast cancer metastasis and subsequent bone destruction

    SciTech Connect

    Son, Jieun; Lee, Jong-Ho; Kim, Ha-Neui; Ha, Hyunil Lee, Zang Hee

    2010-07-23

    Research highlights: {yields} CREB is highly expressed in advanced breast cancer cells. {yields} Tumor-related factors such as TGF-{beta} further elevate CREB expression. {yields} CREB upregulation stimulates metastatic potential of breast cancer cells. {yields} CREB signaling is required for breast cancer-induced bone destruction. -- Abstract: cAMP-response-element-binding protein (CREB) signaling has been reported to be associated with cancer development and poor clinical outcome in various types of cancer. However, it remains to be elucidated whether CREB is involved in breast cancer development and osteotropism. Here, we found that metastatic MDA-MB-231 breast cancer cells exhibited higher CREB expression than did non-metastatic MCF-7 cells and that CREB expression was further increased by several soluble factors linked to cancer progression, such as IL-1, IGF-1, and TGF-{beta}. Using wild-type CREB and a dominant-negative form (K-CREB), we found that CREB signaling positively regulated the proliferation, migration, and invasion of MDA-MB-231 cells. In addition, K-CREB prevented MDA-MB-231 cell-induced osteolytic lesions in a mouse model of cancer metastasis. Furthermore, CREB signaling in cancer cells regulated the gene expression of PTHrP, MMPs, and OPG, which are closely involved in cancer metastasis and bone destruction. These results indicate that breast cancer cells acquire CREB overexpression during their development and that this CREB upregulation plays an important role in multiple steps of breast cancer bone metastasis.

  17. Heparan sulfate regulates the number and centrosome positioning of Drosophila male germline stem cells

    PubMed Central

    Levings, Daniel C.; Arashiro, Takeshi; Nakato, Hiroshi

    2016-01-01

    Stem cell division is tightly controlled via secreted signaling factors and cell adhesion molecules provided from local niche structures. Molecular mechanisms by which each niche component regulates stem cell behaviors remain to be elucidated. Here we show that heparan sulfate (HS), a class of glycosaminoglycan chains, regulates the number and asymmetric division of germline stem cells (GSCs) in the Drosophila testis. We found that GSC number is sensitive to the levels of 6-O sulfate groups on HS. Loss of 6-O sulfation also disrupted normal positioning of centrosomes, a process required for asymmetric division of GSCs. Blocking HS sulfation specifically in the niche, termed the hub, led to increased GSC numbers and mispositioning of centrosomes. The same treatment also perturbed the enrichment of Apc2, a component of the centrosome-anchoring machinery, at the hub–GSC interface. This perturbation of the centrosome-anchoring process ultimately led to an increase in the rate of spindle misorientation and symmetric GSC division. This study shows that specific HS modifications provide a novel regulatory mechanism for stem cell asymmetric division. The results also suggest that HS-mediated niche signaling acts upstream of GSC division orientation control. PMID:26792837

  18. PKCβ Positively Regulates RANKL-Induced Osteoclastogenesis by Inactivating GSK-3β

    PubMed Central

    Shin, Jihye; Jang, Hyunduk; Lin, Jingjing; Lee, Soo Young

    2014-01-01

    Protein kinase C (PKC) family members phosphorylate a wide variety of protein targets and are known to be involved in diverse cellular signaling pathways. However, the role of PKC in receptor activator of NF-κB ligand (RANKL) signaling has remained elusive. We now demonstrate that PKCβ acts as a positive regulator which inactivates glycogen synthase kinase-3β (GSK-3β) and promotes NFATc1 induction during RANKL-induced osteoclastogenesis. Among PKCs, PKCβ expression is increased by RANKL. Pharmacological inhibition of PKCβ decreased the formation of osteoclasts which was caused by the inhibition of NFATc1 induction. Importantly, the phosphorylation of GSK-3β was decreased by PKCβ inhibition. Likewise, down-regulation of PKCβ by RNA interference suppressed osteoclast differentiation, NFATc1 induction, and GSK-3β phosphorylation. The administration of PKC inhibitor to the RANKL-injected mouse calvaria efficiently protected RANKL-induced bone destruction. Thus, the PKCβ pathway, leading to GSK-3β inactivation and NFATc1 induction, has a key role in the differentiation of osteoclasts. Our results also provide a further rationale for PKCβ’s therapeutic targeting to treat inflammation-related bone diseases. PMID:25256217

  19. Notch and TGFβ form a positive regulatory loop and regulate EMT in epithelial ovarian cancer cells.

    PubMed

    Zhou, Jiesi; Jain, Saket; Azad, Abul K; Xu, Xia; Yu, Hai Chuan; Xu, Zhihua; Godbout, Roseline; Fu, YangXin

    2016-08-01

    Epithelial-mesenchymal transition (EMT) plays a critical role in the progression of epithelial ovarian cancer (EOC). However, the mechanisms that regulate EMT in EOC are not fully understood. Here, we report that activation of Notch1 induces EMT in EOC cells as evidenced by downregulation of E-cadherin and cytokeratins, upregulation of Slug and Snail, as well as morphological changes. Interestingly, activation of Notch1 increases TGFβ/Smad signaling by upregulating the expression of TGFβ and TGFβ type 1 receptor. Time course experiments demonstrate that inhibition of Notch by DAPT (a γ-secretase inhibitor) decreases TGFβ-induced phosphorylation of receptor Smads at late, but not at early, timepoints. These results suggest that Notch activation plays a role in sustaining TGFβ/Smad signaling in EOC cells. Furthermore, inhibition of Notch by DAPT decreases TGFβ induction of Slug and repression of E-cadherin and knockdown of Notch1 decreases TGFβ-induced repression of E-cadherin, indicating that Notch is required, at least in part, for TGFβ-induced EMT in EOC cells. On the other hand, TGFβ treatment increases the expression of Notch ligand Jagged1 and Notch target gene HES1 in EOC cells. Functionally, the combination of Notch1 activation and TGFβ treatment is more potent in promoting motility and migration of EOC cells than either stimulation alone. Taken together, our results indicate that Notch and TGFβ form a reciprocal positive regulatory loop and cooperatively regulate EMT and promote EOC cell motility and migration. PMID:27075926

  20. Positive and negative regulation of odor receptor gene choice in Drosophila by acj6.

    PubMed

    Bai, Lei; Goldman, Aaron L; Carlson, John R

    2009-10-14

    Little is known about how individual olfactory receptor neurons (ORNs) select, from among many odor receptor genes, which genes to express. Abnormal chemosensory jump 6 (Acj6) is a POU domain transcription factor essential for the specification of ORN identity and odor receptor (Or) gene expression in the Drosophila maxillary palp, one of the two adult olfactory organs. However, the mechanism by which Acj6 functions in this process has not been investigated. Here, we systematically examine the role of Acj6 in the maxillary palp and in a major subset of antennal ORNs. We define an Acj6 binding site by a reiterative in vitro selection process. The site is found upstream of Or genes regulated by Acj6, and Acj6 binds to the site in Or promoters. Mutational analysis shows that the site is essential for Or regulation in vivo. Surprisingly, a novel ORN class in acj6 adults is found to arise from ectopic expression of a larval Or gene, which is repressed in wild type via an Acj6 binding site. Thus, Acj6 acts directly in the process of receptor gene choice; it plays a dual role, positive and negative, in the logic of the process, and acts in partitioning the larval and adult receptor repertoires. PMID:19828808

  1. A Position Paper on the Roles of Federal, State and Local Governments on Standards, Regulations and Laws for Day Care.

    ERIC Educational Resources Information Center

    Zaccaria, Michael A.; Hollomon, John W.

    The goals of this position paper are: (1) to describe some specific roles the federal state and local governments can play in regard to child care standards and regulations and (2) to make some straightforward and down-to-earth suggestions, which should undergird national child care standards and regulations, as these relate to day care. Some of…

  2. Transcription factor interactions: Selectors of positive or negative regulation from a single DNA element

    SciTech Connect

    Diamond, M.I.; Miner, J.N.; Yoshinaga, S.K.; Yamamoto, K.R. )

    1990-09-14

    The mechanism by which a single factor evokes opposite regulatory effects from a specific DNA sequence is not well understood. In this study, a 25-base pair element that resides upstream of the mouse proliferin gene was examined; it conferred on linked promoters either positive or negative glucocorticoid regulation, depending upon physiological context. This sequence, denoted a composite glucocorticoid response element (GRE), was bound selective in vitro both by the glucocorticoid receptor and by c-Jun and c-Fos, components of the phorbol ester-activated AP-1 transcription factor. Indeed, c-Jun and c-Fos served as selectors of hormone responsiveness: the composite GRE was inactive in the absence of c-Jun, whereas it conferred a positive glucocorticoid effect in the presence of c-Jun, and a negative glucocorticoid effect in the presence of c-Jun and relatively high levels of c-Fos. The receptor also interacted selectively with c-Jun in vitro. A general model for composite GRE action is proposed that invokes both DNA binding and protein-protein interactions by receptor and nonreceptor factors.

  3. Arabidopsis COP1-interacting protein 1 is a positive regulator of ABA response.

    PubMed

    Ren, Chenxia; Zhu, Xili; Zhang, Pingping; Gong, Qingqiu

    2016-09-01

    COP1-interacting protein 1 (CIP1, At5g41790) was the first reported interacting protein for CONSTITUTIVE PHOTOMORPHOGENIC 1 (COP1) of Arabidopsis; however its physiological function has remained unknown for two decades. Here we show that CIP1 is a positive regulator of abscisic acid (ABA) response. CIP1 is mainly expressed in the photosynthetic cells and the vascular tissue, and its promoter activity can be induced by osmotic stress and ABA. The CIP1 protein is localized to the plasma membrane. A T-DNA insertion mutant cip1-1 was then characterized. The mutant is sensitive to osmotic stress and has ABA insensitive phenotypes. RNA sequencing showed that cip1-1 has lower levels of gene expression in abiotic stress response compared with the wild-type. Meanwhile, transcript levels of ABA biosynthesis genes are higher in cip1-1 than in the wild-type. These results suggested that CIP1 is positively involved in ABA response. PMID:27372427

  4. Quantitative trait gene Slit2 positively regulates murine hematopoietic stem cell numbers.

    PubMed

    Waterstrat, Amanda; Rector, Kyle; Geiger, Hartmut; Liang, Ying

    2016-01-01

    Hematopoietic stem cells (HSC) demonstrate natural variation in number and function. The genetic factors responsible for the variations (or quantitative traits) are largely unknown. We previously identified a gene whose differential expression underlies the natural variation of HSC numbers in C57BL/6 (B6) and DBA/2 (D2) mice. We now report the finding of another gene, Slit2, on chromosome 5 that also accounts for variation in HSC number. In reciprocal chromosome 5 congenic mice, introgressed D2 alleles increased HSC numbers, whereas B6 alleles had the opposite effect. Using gene array and quantitative polymerase chain reaction, we identified Slit2 as a quantitative trait gene whose expression was positively correlated with the number of HSCs. Ectopic expression of Slit2 not only increased the number of the long-term colony forming HSCs, but also enhanced their repopulation capacity upon transplantation. Therefore, Slit2 is a novel quantitative trait gene and a positive regulator of the number and function of murine HSCs. This finding suggests that Slit2 may be a potential therapeutic target for the effective in vitro and in vivo expansion of HSCs without compromising normal hematopoiesis. PMID:27503415

  5. Quantitative trait gene Slit2 positively regulates murine hematopoietic stem cell numbers

    PubMed Central

    Waterstrat, Amanda; Rector, Kyle; Geiger, Hartmut; Liang, Ying

    2016-01-01

    Hematopoietic stem cells (HSC) demonstrate natural variation in number and function. The genetic factors responsible for the variations (or quantitative traits) are largely unknown. We previously identified a gene whose differential expression underlies the natural variation of HSC numbers in C57BL/6 (B6) and DBA/2 (D2) mice. We now report the finding of another gene, Slit2, on chromosome 5 that also accounts for variation in HSC number. In reciprocal chromosome 5 congenic mice, introgressed D2 alleles increased HSC numbers, whereas B6 alleles had the opposite effect. Using gene array and quantitative polymerase chain reaction, we identified Slit2 as a quantitative trait gene whose expression was positively correlated with the number of HSCs. Ectopic expression of Slit2 not only increased the number of the long-term colony forming HSCs, but also enhanced their repopulation capacity upon transplantation. Therefore, Slit2 is a novel quantitative trait gene and a positive regulator of the number and function of murine HSCs. This finding suggests that Slit2 may be a potential therapeutic target for the effective in vitro and in vivo expansion of HSCs without compromising normal hematopoiesis. PMID:27503415

  6. Making an effort to feel positive: insecure attachment in infancy predicts the neural underpinnings of emotion regulation in adulthood

    PubMed Central

    Moutsiana, Christina; Fearon, Pasco; Murray, Lynne; Cooper, Peter; Goodyer, Ian; Johnstone, Tom; Halligan, Sarah

    2014-01-01

    Background Animal research indicates that the neural substrates of emotion regulation may be persistently altered by early environmental exposures. If similar processes operate in human development then this is significant, as the capacity to regulate emotional states is fundamental to human adaptation. Methods We utilised a 22-year longitudinal study to examine the influence of early infant attachment to the mother, a key marker of early experience, on neural regulation of emotional states in young adults. Infant attachment status was measured via objective assessment at 18-months, and the neural underpinnings of the active regulation of affect were studied using fMRI at age 22 years. Results Infant attachment status at 18-months predicted neural responding during the regulation of positive affect 20-years later. Specifically, while attempting to up-regulate positive emotions, adults who had been insecurely versus securely attached as infants showed greater activation in prefrontal regions involved in cognitive control and reduced co-activation of nucleus accumbens with prefrontal cortex, consistent with relative inefficiency in the neural regulation of positive affect. Conclusions Disturbances in the mother–infant relationship may persistently alter the neural circuitry of emotion regulation, with potential implications for adjustment in adulthood. PMID:24397574

  7. Telomere position effect: regulation of gene expression with progressive telomere shortening over long distances.

    PubMed

    Robin, Jérôme D; Ludlow, Andrew T; Batten, Kimberly; Magdinier, Frédérique; Stadler, Guido; Wagner, Kathyrin R; Shay, Jerry W; Wright, Woodring E

    2014-11-15

    While global chromatin conformation studies are emerging, very little is known about the chromatin conformation of human telomeres. Most studies have focused on the role of telomeres as a tumor suppressor mechanism. Here we describe how telomere length regulates gene expression long before telomeres become short enough to produce a DNA damage response (senescence). We directly mapped the interactions adjacent to specific telomere ends using a Hi-C (chromosome capture followed by high-throughput sequencing) technique modified to enrich for specific genomic regions. We demonstrate that chromosome looping brings the telomere close to genes up to 10 Mb away from the telomere when telomeres are long and that the same loci become separated when telomeres are short. Furthermore, expression array analysis reveals that many loci, including noncoding RNAs, may be regulated by telomere length. We report three genes (ISG15 [interferon-stimulated gene 15 kd], DSP [Desmoplakin], and C1S [complement component 1s subcomplement]) located at three different subtelomeric ends (1p, 6p, and 12p) whose expressions are altered with telomere length. Additionally, we confirmed by in situ analysis (3D-FISH [three-dimensional fluorescence in situ hybridization]) that chromosomal looping occurs between the loci of those genes and their respective telomere ends. We term this process TPE-OLD for "telomere position effect over long distances." Our results suggest a potential novel mechanism for how telomere shortening could contribute to aging and disease initiation/progression in human cells long before the induction of a critical DNA damage response. PMID:25403178

  8. Crystal Structure of Human Cyclin K, A Positive Regulator of Cyclin-Dependent Kinase 9

    SciTech Connect

    Baek,K.; Brown, R.; Birrane, G.; Ladias, J.

    2007-01-01

    K and the closely related cyclins T1, T2a, and T2b interact with cyclin-dependent kinase 9 (CDK9) forming multiple nuclear complexes, referred to collectively as positive transcription elongation factor b (P-TEFb). Through phosphorylation of the C-terminal domain of the RNA polymerase II largest subunit, distinct P-TEFb species regulate the transcriptional elongation of specific genes that play central roles in human physiology and disease development, including cardiac hypertrophy and human immunodeficiency virus-1 pathogenesis. We have determined the crystal structure of human cyclin K (residues 11-267) at 1.5 {angstrom} resolution, which represents the first atomic structure of a P-TEFb subunit. The cyclin K fold comprises two typical cyclin boxes with two short helices preceding the N-terminal box. A prominent feature of cyclin K is an additional helix (H4a) in the first cyclin box that obstructs the binding pocket for the cell-cycle inhibitor p27{sup Kip1}. Modeling of CDK9 bound to cyclin K provides insights into the structural determinants underlying the formation and regulation of this complex. A homology model of human cyclin T1 generated using the cyclin K structure as a template reveals that the two proteins have similar structures, as expected from their high level of sequence identity. Nevertheless, their CDK9-interacting surfaces display significant structural differences, which could potentially be exploited for the design of cyclin-targeted inhibitors of the CDK9-cyclin K and CDK9-cyclin T1 complexes.

  9. Crystal structure of human cyclin K, a positive regulator of cyclin-dependent kinase 9.

    PubMed

    Baek, Kyuwon; Brown, Raymond S; Birrane, Gabriel; Ladias, John A A

    2007-02-16

    Cyclin K and the closely related cyclins T1, T2a, and T2b interact with cyclin-dependent kinase 9 (CDK9) forming multiple nuclear complexes, referred to collectively as positive transcription elongation factor b (P-TEFb). Through phosphorylation of the C-terminal domain of the RNA polymerase II largest subunit, distinct P-TEFb species regulate the transcriptional elongation of specific genes that play central roles in human physiology and disease development, including cardiac hypertrophy and human immunodeficiency virus-1 pathogenesis. We have determined the crystal structure of human cyclin K (residues 11-267) at 1.5 A resolution, which represents the first atomic structure of a P-TEFb subunit. The cyclin K fold comprises two typical cyclin boxes with two short helices preceding the N-terminal box. A prominent feature of cyclin K is an additional helix (H4a) in the first cyclin box that obstructs the binding pocket for the cell-cycle inhibitor p27(Kip1). Modeling of CDK9 bound to cyclin K provides insights into the structural determinants underlying the formation and regulation of this complex. A homology model of human cyclin T1 generated using the cyclin K structure as a template reveals that the two proteins have similar structures, as expected from their high level of sequence identity. Nevertheless, their CDK9-interacting surfaces display significant structural differences, which could potentially be exploited for the design of cyclin-targeted inhibitors of the CDK9-cyclin K and CDK9-cyclin T1 complexes. PMID:17169370

  10. Crystal Structure of Human Cyclin K, a Positive Regulator of Cyclin-dependent Kinase 9

    PubMed Central

    Baek, Kyuwon; Brown, Raymond S.; Birrane, Gabriel; Ladias, John A.A.

    2007-01-01

    Summary Cyclin K and the closely related cyclins T1, T2a, and T2b interact with cyclin-dependent kinase 9 (CDK9) forming multiple nuclear complexes, collectively referred to as positive transcription elongation factor b (P-TEFb). Through phosphorylation of the C-terminal domain of the RNA polymerase II largest subunit, distinct P-TEFb species regulate the transcriptional elongation of specific genes that play central roles in human physiology and disease development, including cardiac hypertrophy and human immunodeficiency virus-1 pathogenesis. We have determined the crystal structure of human cyclin K (residues 11-267) at 1.5 Å resolution, which represents the first atomic structure of a P-TEFb subunit. The cyclin K fold comprises two typical cyclin boxes with two short helices preceding the N-terminal box. A prominent feature of cyclin K is an additional helix (H4a) in the first cyclin box that obstructs the binding pocket for the cell cycle inhibitor p27Kip1. Modeling of CDK9 bound to cyclin K provides insights into the structural determinants underlying the formation and regulation of this complex. A homology model of human cyclin T1 generated using the cyclin K as a template reveals that the two proteins have similar structures, as expected from their high sequence identity. Nevertheless, their CDK9-interacting surfaces display significant structural differences, which could potentially be exploited for the design of cyclin-targeted inhibitors of the CDK9–cyclin K and CDK9–cyclin T1 complexes. PMID:17169370

  11. A Positive Role of microRNA-15b on Regulation of Osteoblast Differentiation

    PubMed Central

    Vimalraj, S.; Partridge, Nicola C.; Selvamurugan, N.

    2014-01-01

    Osteoblast differentiation is tightly regulated by several factors including microRNAs (miRNAs). In this paper we report that pre-mir-15b is highly expressed in differentiated osteoblasts. The functional role of miR-15b in osteoblast differentiation was determined using miR-15b mimic/inhibitor and the expression of osteoblast differentiation marker genes such as alkaline phosphatase (ALP), type I collagen genes was decreased by miR-15b inhibitor. Runx2, a bone specific transcription factor is generally required for expression of osteoblast differentiation marker genes and in response to miR-15b inhibitor treatment, Runx2 mRNA expression was not changed; whereas its protein expression was decreased. Even though Smurf1 (SMAD specific E3 ubiquitin protein ligase 1), HDAC4 (histone deacetylase 4), Smad7, and Crim1 were found to be few of miR-15b’s putative target genes, there was increased expression of only Smurf1 gene at mRNA and protein levels by miR-15b inhibitor. miR-15b mimic treatment significantly increased and decreased expressions of Runx2 and Smurf1 proteins, respectively. We further identified that the Smurf1 3’UTR is directly targeted by miR-15b using the luciferase reporter gene system. This is well documented that Smurf1 interacts with Runx2 and degrades it by proteasomal pathway. Hence, based on our results we suggest that miR-15b promotes osteoblast differentiation by indirectly protecting Runx2 protein from Smurf1 mediated degradation. Thus, this study identified that miR-15b can act as a positive regulator for osteoblast differentiation. PMID:24435757

  12. Positioning of extracellular loop 1 affects pore gating of the cystic fibrosis transmembrane conductance regulator.

    PubMed

    Infield, Daniel T; Cui, Guiying; Kuang, Christopher; McCarty, Nael A

    2016-03-01

    The cystic fibrosis (CF) transmembrane conductance regulator (CFTR) is a chloride ion channel, the dysfunction of which directly leads to the life-shortening disease CF. Extracellular loop 1 (ECL1) of CFTR contains several residues involved in stabilizing the open state of the channel; some, including D110, are sites of disease-associated gating mutations. Structures from related proteins suggest that the position of CFTR's extracellular loops may change considerably during gating. To better understand the roles of ECL1 in CFTR function, we utilized functional cysteine cross-linking to determine the effects of modulation of D110C-CFTR and of a double mutant of D110C with K892C in extracellular loop 4 (ECL4). The reducing agent DTT elicited a large potentiation of the macroscopic conductance of D110C/K892C-CFTR, likely due to breakage of a spontaneous disulfide bond between C110 and C892. DTT-reduced D110C/K892C-CFTR was rapidly inhibited by binding cadmium ions with high affinity, suggesting that these residues frequently come in close proximity in actively gating channels. Effects of DTT and cadmium on modulation of pore gating were demonstrated at the single-channel level. Finally, disulfided D110C/K892C-CFTR channels were found to be less sensitive than wild-type or DTT-treated D110C/K892C-CFTR channels to stimulation by IBMX, suggesting an impact of this conformational restriction on channel activation by phosphorylation. The results are best explained in the context of a model of CFTR gating wherein stable channel opening requires correct positioning of functional elements structurally influenced by ECL1. PMID:26684250

  13. The ilvIH operon of Escherichia coli is positively regulated.

    PubMed Central

    Platko, J V; Willins, D A; Calvo, J M

    1990-01-01

    The ilvIH operon of Escherichia coli (located near min 2) encodes acetohydroxyacid synthase III, an isozyme involved in branched-chain amino acid biosynthesis. A strain with lacZ fused to the ilvIH promoter was constructed. Transposon Tn10 was introduced into this strain, and tetracycline-resistant derivatives were screened for those in which ilvIH promoter expression was markedly reduced. In one such derivative, strain CV1008, beta-galactosidase expression was reduced more than 30-fold. The transposon giving rise to this phenotype inserted near min 20 on the E. coli chromosome. Extract from a wild-type strain contains a protein, the IHB protein, that binds to two sites upstream of the ilvIH promoter (E. Ricca, D. A. Aker, and J. M. Calvo, J. Bacteriol. 171:1658-1664, 1989). Extract from strain CV1008 lacks IHB-binding activity. These results indicate that the IHB protein is a positive regulator of ilvIH operon expression. The gene that encodes the IHB protein, ihb, was cloned by complementing the transposon-induced mutation. Definitive evidence that the cloned DNA encodes the IHB protein was provided by determining the sequence of more than 17 amino acids at the N terminus of the IHB protein and comparing it with the nucleotide sequence. A mutation that prevents repression of the ilvIH operon by leucine in vivo and that alters the DNA-binding characteristics of the IHB protein in vitro was shown to be an allele of the ihb gene. The ihb gene is identical to oppI, a gene that regulates the oppABCDF operon (E. A. Austin, J. C. Andrews, and S. A. Short, Abstr. Mol. Genet. Bacteria Phages, p. 153, 1989). Thus, oppI/ihb encodes a protein that regulates both ilvIH, an operon that is repressed by leucine, and oppABCDF, an operon involved in peptide transport that is induced by leucine. We propose that the designation lrp be used in the future instead of oppI or ihb and that Lrp (leucine-responsive regulatory protein) be used in place of IHB. Images PMID:2115869

  14. Chromatin regulates DNA torsional energy via topoisomerase II-mediated relaxation of positive supercoils

    PubMed Central

    Fernández, Xavier; Díaz-Ingelmo, Ofelia; Martínez-García, Belén; Roca, Joaquim

    2014-01-01

    Eukaryotic topoisomerases I (topo I) and II (topo II) relax the positive (+) and negative (−) DNA torsional stress (TS) generated ahead and behind the transcription machinery. It is unknown how this DNA relaxation activity is regulated and whether (+) and (−)TS are reduced at similar rates. Here, we used yeast circular minichromosomes to conduct the first comparative analysis of topo I and topo II activities in relaxing chromatin under (+) and (−)TS. We observed that, while topo I relaxed (+) and (−)TS with similar efficiency, topo II was more proficient and relaxed (+)TS more quickly than (−)TS. Accordingly, we found that the relaxation rate of (+)TS by endogenous topoisomerases largely surpassed that of (−)TS. We propose a model of how distinct conformations of chromatin under (+) and (−)TS may produce this unbalanced relaxation of DNA. We postulate that, while quick relaxation of (+)TS may facilitate the progression of RNA and DNA polymerases, slow relaxation of (−)TS may serve to favor DNA unwinding and other structural transitions at specific regions often required for genomic transactions. PMID:24859967

  15. Positive feedback regulation of p53 transactivity by DNA damage-induced ISG15 modification

    PubMed Central

    Park, Jong Ho; Yang, Seung Wook; Park, Jung Mi; Ka, Seung Hyeun; Kim, Ji-Hoon; Kong, Young-Yun; Jeon, Young Joo; Seol, Jae Hong; Chung, Chin Ha

    2016-01-01

    p53 plays a pivotal role in tumour suppression under stresses, such as DNA damage. ISG15 has been implicated in the control of tumorigenesis. Intriguingly, the expression of ISG15, UBE1L and UBCH8 is induced by DNA-damaging agents, such as ultraviolet and doxorubicin, which are known to induce p53. Here, we show that the genes encoding ISG15, UBE1L, UBCH8 and EFP, have the p53-responsive elements and their expression is induced in a p53-dependent fashion under DNA damage conditions. Furthermore, DNA damage induces ISG15 conjugation to p53 and this modification markedly enhances the binding of p53 to the promoters of its target genes (for example, CDKN1 and BAX) as well as of its own gene by promoting phosphorylation and acetylation, leading to suppression of cell growth and tumorigenesis. These findings establish a novel feedback circuit between p53 and ISG15-conjugating system for positive regulation of the tumour suppressive function of p53 under DNA damage conditions. PMID:27545325

  16. Higd1a is a positive regulator of cytochrome c oxidase

    PubMed Central

    Hayashi, Takaharu; Asano, Yoshihiro; Shintani, Yasunori; Aoyama, Hiroshi; Kioka, Hidetaka; Tsukamoto, Osamu; Hikita, Masahide; Shinzawa-Itoh, Kyoko; Takafuji, Kazuaki; Higo, Shuichiro; Kato, Hisakazu; Yamazaki, Satoru; Matsuoka, Ken; Nakano, Atsushi; Asanuma, Hiroshi; Asakura, Masanori; Minamino, Tetsuo; Goto, Yu-ichi; Ogura, Takashi; Kitakaze, Masafumi; Komuro, Issei; Sakata, Yasushi; Tsukihara, Tomitake; Yoshikawa, Shinya; Takashima, Seiji

    2015-01-01

    Cytochrome c oxidase (CcO) is the only enzyme that uses oxygen to produce a proton gradient for ATP production during mitochondrial oxidative phosphorylation. Although CcO activity increases in response to hypoxia, the underlying regulatory mechanism remains elusive. By screening for hypoxia-inducible genes in cardiomyocytes, we identified hypoxia inducible domain family, member 1A (Higd1a) as a positive regulator of CcO. Recombinant Higd1a directly integrated into highly purified CcO and increased its activity. Resonance Raman analysis revealed that Higd1a caused structural changes around heme a, the active center that drives the proton pump. Using a mitochondria-targeted ATP biosensor, we showed that knockdown of endogenous Higd1a reduced oxygen consumption and subsequent mitochondrial ATP synthesis, leading to increased cell death in response to hypoxia; all of these phenotypes were rescued by exogenous Higd1a. These results suggest that Higd1a is a previously unidentified regulatory component of CcO, and represents a therapeutic target for diseases associated with reduced CcO activity. PMID:25605899

  17. A molecular mechanism to regulate lysosome motility for lysosome positioning and tubulation.

    PubMed

    Li, Xinran; Rydzewski, Nicholas; Hider, Ahmad; Zhang, Xiaoli; Yang, Junsheng; Wang, Wuyang; Gao, Qiong; Cheng, Xiping; Xu, Haoxing

    2016-04-01

    To mediate the degradation of biomacromolecules, lysosomes must traffic towards cargo-carrying vesicles for subsequent membrane fusion or fission. Mutations of the lysosomal Ca(2+) channel TRPML1 cause lysosomal storage disease (LSD) characterized by disordered lysosomal membrane trafficking in cells. Here we show that TRPML1 activity is required to promote Ca(2+)-dependent centripetal movement of lysosomes towards the perinuclear region (where autophagosomes accumulate) following autophagy induction. ALG-2, an EF-hand-containing protein, serves as a lysosomal Ca(2+) sensor that associates physically with the minus-end-directed dynactin-dynein motor, while PtdIns(3,5)P(2), a lysosome-localized phosphoinositide, acts upstream of TRPML1. Furthermore, the PtdIns(3,5)P(2)-TRPML1-ALG-2-dynein signalling is necessary for lysosome tubulation and reformation. In contrast, the TRPML1 pathway is not required for the perinuclear accumulation of lysosomes observed in many LSDs, which is instead likely to be caused by secondary cholesterol accumulation that constitutively activates Rab7-RILP-dependent retrograde transport. Ca(2+) release from lysosomes thus provides an on-demand mechanism regulating lysosome motility, positioning and tubulation. PMID:26950892

  18. RNA-mediated regulation in Gram-positive pathogens: an overview punctuated with examples from the group A Streptococcus

    PubMed Central

    Miller, Eric W.; Cao, Tram N.; Pflughoeft, Kathryn J.; Sumby, Paul

    2014-01-01

    RNA-based mechanisms of regulation represent a ubiquitous class of regulators that are associated with diverse processes including nutrient sensing, stress response, modulation of horizontal gene transfer, and virulence factor expression. While better studied in Gram-negative bacteria, the literature is replete with examples of the importance of RNA-mediated regulatory mechanisms to the virulence and fitness of Gram-positives. Regulatory RNAs are classified as cis-acting, e.g. riboswitches, which modulate the transcription, translation, or stability of co-transcribed RNA, or trans-acting, e.g. small regulatory RNAs, which target separate mRNAs or proteins. The group A Streptococcus (GAS, Streptococcus pyogenes) is a Gram-positive bacterial pathogen from which several regulatory RNA mechanisms have been characterized. The study of RNA-mediated regulation in GAS has uncovered novel concepts with respect to how small regulatory RNAs may positively regulate target mRNA stability, and to how CRISPR RNAs are processed from longer precursors. This review provides an overview of RNA-mediated regulation in Gram-positive bacteria, and is highlighted with specific examples from GAS research. The key roles that these systems play in regulating bacterial virulence are discussed and future perspectives outlined. PMID:25091277

  19. Regulation of alkane degradation pathway by a TetR family repressor via an autoregulation positive feedback mechanism in a Gram-positive Dietzia bacterium.

    PubMed

    Liang, Jie-Liang; Nie, Yong; Wang, Miaoxiao; Xiong, Guangming; Wang, Yi-Ping; Maser, Edmund; Wu, Xiao-Lei

    2016-01-01

    n-Alkanes are ubiquitous in nature and serve as important carbon sources for both Gram-positive and Gram-negative bacteria. Hydroxylation of n-alkanes by alkane monooxygenases is the first and most critical step in n-alkane metabolism. However, regulation of alkane degradation genes in Gram-positive bacteria remains poorly characterized. We therefore explored the transcriptional regulation of an alkB-type alkane hydroxylase-rubredoxin fusion gene, alkW1, from Dietzia sp. DQ12-45-1b. The alkW1 promoter was characterized and so was the putative TetR family regulator, AlkX, located downstream of alkW1 gene. We further identified an unusually long 48 bp inverted repeat upstream of alkW1 and demonstrated the binding of AlkX to this operator. Analytical ultracentrifugation and microcalorimetric results indicated that AlkX formed stable dimers in solution and two dimers bound to one operator in a positive cooperative fashion characterized by a Hill coefficient of 1.64 (± 0.03) [k(D)  = 1.06 (± 0.16) μM, k(D) ' = 0.05 (± 0.01) μM]. However, the DNA-binding affinity was disrupted in the presence of long-chain fatty acids (C10-C24), suggesting that AlkX can sense the concentrations of n-alkane degradation metabolites. A model was therefore proposed where AlkX controls alkW1 expression in a metabolite-dependent manner. Bioinformatic analysis revealed that the alkane hydroxylase gene regulation mechanism may be common among Actinobacteria. PMID:26418273

  20. Genes Regulated by Vitamin D in Bone Cells Are Positively Selected in East Asians

    PubMed Central

    Chen, Yuan; Xue, Yali; Luiselli, Donata; Tyler-Smith, Chris; Pagani, Luca; Ayub, Qasim

    2015-01-01

    Vitamin D and folate are activated and degraded by sunlight, respectively, and the physiological processes they control are likely to have been targets of selection as humans expanded from Africa into Eurasia. We investigated signals of positive selection in gene sets involved in the metabolism, regulation and action of these two vitamins in worldwide populations sequenced by Phase I of the 1000 Genomes Project. Comparing allele frequency-spectrum-based summary statistics between these gene sets and matched control genes, we observed a selection signal specific to East Asians for a gene set associated with vitamin D action in bones. The selection signal was mainly driven by three genes CXXC finger protein 1 (CXXC1), low density lipoprotein receptor-related protein 5 (LRP5) and runt-related transcription factor 2 (RUNX2). Examination of population differentiation and haplotypes allowed us to identify several candidate causal regulatory variants in each gene. Four of these candidate variants (one each in CXXC1 and RUNX2 and two in LRP5) had a >70% derived allele frequency in East Asians, but were present at lower (20–60%) frequency in Europeans as well, suggesting that the adaptation might have been part of a common response to climatic and dietary changes as humans expanded out of Africa, with implications for their role in vitamin D-dependent bone mineralization and osteoporosis insurgence. We also observed haplotype sharing between East Asians, Finns and an extinct archaic human (Denisovan) sample at the CXXC1 locus, which is best explained by incomplete lineage sorting. PMID:26719974

  1. Positive regulation of the Egr-1/osteopontin positive feedback loop in rat vascular smooth muscle cells by TGF-{beta}, ERK, JNK, and p38 MAPK signaling

    SciTech Connect

    Yu, Hong-Wei; Liu, Qi-Feng; Liu, Gui-Nan

    2010-05-28

    Previous studies identified a positive feedback loop in rat vascular smooth muscle cells (VSMCs) in which early growth response factor-1 (Egr-1) binds to the osteopontin (OPN) promoter and upregulates OPN expression, and OPN upregulates Egr-1 expression via the extracellular signal-regulated protein kinase (ERK) signaling pathway. The current study examined whether transforming growth factor-{beta} (TGF-{beta}) activity contributes to Egr-1 binding to the OPN promoter, and whether other signaling pathways act downstream of OPN to regulate Egr-1 expression. ChIP assays using an anti-Egr-1 antibody showed that amplification of the OPN promoter sequence decreased in TGF-{beta} DNA enzyme-transfected VSMCs relative to control VSMCs. Treatment of VSMCs with PD98059 (ERK inhibitor), SP600125 (JNK inhibitor), or SB203580 (p38 MAPK inhibitor) significantly inhibited OPN-induced Egr-1 expression, and PD98059 treatment was associated with the most significant decrease in Egr-1 expression. OPN-stimulated VSMC cell migration was inhibited by SP600125 or SB203580, but not by PD98059. Furthermore, MTT assays showed that OPN-mediated cell proliferation was inhibited by PD98059, but not by SP600125 or SB203580. Taken together, the results of the current study show that Egr-1 binding to the OPN promoter is positively regulated by TGF-{beta}, and that the p38 MAPK, JNK, and ERK pathways are involved in OPN-mediated Egr-1 upregulation.

  2. Maternal Positive and Negative Interaction Behaviors and Early Adolescents' Depressive Symptoms: Adolescent Emotion Regulation as a Mediator

    ERIC Educational Resources Information Center

    Yap, Marie B. H.; Schwartz, Orli S.; Byrne, Michelle L.; Simmons, Julian G.; Allen, Nicholas B.

    2010-01-01

    This study examined the relation between mothers' positive and negative interaction behaviors during mother-child interactions and the emotion regulation (ER) and depressive symptoms of their adolescent offspring. Event-planning (EPI) and problem-solving interactions (PSI) were observed in 163 mother-adolescent dyads, and adolescents also provided…

  3. Causal Judgments of Positive Mood in Relation to Self-Regulation: A Case Study with Flemish Students

    ERIC Educational Resources Information Center

    Human-Vogel, Salome; van Petegem, Peter

    2008-01-01

    To examine students' causal judgements of positive mood in relation to self-regulation, 128 participants from two different schools representing two distinct educational environments (Technical/Vocational School (TSO/BSO): N = 63; General Secondary School (ASO): N = 65) were asked to judge 45 statements containing three possible relationships (A…

  4. Longitudinal Study of Self-Regulation, Positive Parenting, and Adjustment Problems among Physically Abused Children

    ERIC Educational Resources Information Center

    Kim-Spoon, Jungmeen.; Haskett, Mary E.; Longo, Gregory S.; Nice, Rachel.

    2012-01-01

    Objective: Research using normative and high-risk samples indicates a significant link between problems with self-regulation and child maladjustment. Nevertheless, little is known about the processes that may modify the link between self-regulation and maladjustment. This longitudinal study examined the joint contributions of child self-regulation…

  5. Interleukin 17 Regulates Mer Tyrosine Kinase–Positive Cells in Pseudomonas aeruginosa Keratitis

    PubMed Central

    Li, Cui; McClellan, Sharon A.; Barrett, Ronald; Hazlett, Linda D.

    2014-01-01

    Purpose. To determine if IL-17 regulates Mer tyrosine kinase–positive (MerTK+) cells in Pseudomonas aeruginosa keratitis. Methods. Interleukin 17 was tested in normal and infected cornea of susceptible C57BL/6 and resistant BALB/c mice. The latter were treated with recombinant mouse (rm) IL-17; both groups were treated with IL-17 neutralizing antibody. Mice were infected, and clinical score, PCR, ELISA, and myeloperoxidase (MPO) assays tested expression of proinflammatory and anti-inflammatory mediators and polymorphonuclear neutrophilic leukocyte (PMN) infiltrate. Fas and Fas ligand (FasL) protein levels were assessed in both mouse strains, while MerTK+ cells were examined by immunostaining and cell sorting before and after IL-17 neutralization. Results. The IL-17 mRNA and protein were higher in C57BL/6 versus BALB/c cornea after infection. The rmIL-17 treatment of BALB/c mice modified proinflammatory and anti-inflammatory mediators, but clinical score and MPO assay revealed no differences. However, only BALB/c mice treated with IL-17 neutralizing antibody showed increased disease, macrophage inflammatory protein (MIP) 2, and MPO levels. Fas and FasL protein levels, elevated earlier in BALB/c versus C57BL/6 mice, correlated with significantly more MerTK+ cells in BALB/c cornea at 3 days after infection. Neutralization of IL-17 in C57BL/6 mice elevated MerTK+ cells, while similar treatment of BALB/c mice significantly decreased them. Conclusions. These data provide evidence that IL-17 expression is higher in C57BL/6 versus BALB/c cornea after infection and that the latter group has more MerTK+ cells. Exogenous rmIL-17 failed to shift the disease response in resistant mice, but its neutralization resulted in worsened disease and reduced MerTK+ cells. Neutralization of IL-17 in C57BL/6 mice increased MerTK+ cells but did not dramatically shift the disease response. PMID:25298414

  6. Mothers' attachment styles and their children's self-reported security, as related to maternal socialization of children's positive affect regulation.

    PubMed

    Gentzler, Amy L; Ramsey, Meagan A; Black, Katelyn R

    2015-01-01

    This study investigated how mothers' attachment was related to their responses to their own and their children's positive events and positive affect (PA). Ninety-seven mothers reported on their attachment and their responses to their own and their 7-12-year-old children's positive events and emotions. Children reported on their mothers' responses to the children's positive events and their attachment security with their mothers. The results indicated that more avoidant mothers reported less intense PA in response to their own and their children's positive events. More avoidant mothers also were less likely to encourage their children to savor positive events (through expressing PA, reflecting on PA or themselves, giving rewards, and affectionate responses). Mothers higher on anxiety reported greater likelihood of dampening (e.g., minimizing the event's importance) their own positive events and reported being more likely to feel discomfort and to reprimand their children for expressing PA. Children's security was predicted by mothers' lower likelihood of encouraging children's dampening and of reprimanding children for PA displays. This study advances the literature on how mothers' attachment is related to the ways in which they regulate their own and their children's PA, which may have implications for children's attachment and developing PA regulation. PMID:26095911

  7. Mycobacterium tuberculosis SigM positively regulates Esx secreted protein and nonribosomal peptide synthetase genes and down regulates virulence-associated surface lipid synthesis.

    PubMed

    Raman, Sahadevan; Puyang, Xiaoling; Cheng, Tan-Yun; Young, David C; Moody, D Branch; Husson, Robert N

    2006-12-01

    The Mycobacterium tuberculosis genome encodes 12 alternative sigma factors, several of which regulate stress responses and are required for virulence in animal models of acute infection. In this work we investigated M. tuberculosis SigM, a member of the extracytoplasmic function subfamily of alternative sigma factors. This sigma factor is expressed at low levels in vitro and does not appear to function in stress response regulation. Instead, SigM positively regulates genes required for the synthesis of surface or secreted molecules. Among these are genes encoding two pairs of Esx secreted proteins, a multisubunit nonribosomal peptide synthetase operon, and genes encoding two members of the proline-proline-glutamate (PPE) family of proteins. Genes up regulated in a sigM mutant strain include a different PPE gene, as well as several genes involved in surface lipid synthesis. Among these are genes involved in synthesis of phthiocerol dimycocerosate (PDIM), a surface lipid critical for virulence during acute infection, and the kasA-kasB operon, which is required for mycolic acid synthesis. Analysis of surface lipids showed that PDIM synthesis is increased in a sigM-disrupted strain and is undetectable in a sigM overexpression strain. These findings demonstrate that SigM positively and negatively regulates cell surface and secreted molecules that are likely to function in host-pathogen interactions. PMID:17028284

  8. Sirt6 cooperates with Blimp1 to positively regulate osteoclast differentiation.

    PubMed

    Park, So Jeong; Huh, Jeong-Eun; Shin, Jihye; Park, Doo Ri; Ko, Ryeojin; Jin, Gyu-Rin; Seo, Dong-Hyun; Kim, Han-Sung; Shin, Hong-In; Oh, Goo Taeg; Kim, Hyun Seok; Lee, Soo Young

    2016-01-01

    Global deletion of the gene encoding a nuclear histone deacetylase sirtuin 6 (Sirt6) in mice leads to osteopenia with a low bone turnover due to impaired bone formation. But whether Sirt6 regulates osteoclast differentiation is less clear. Here we show that Sirt6 functions as a transcriptional regulator to directly repress anti-osteoclastogenic gene expression. Targeted ablation of Sirt6 in hematopoietic cells including osteoclast precursors resulted in increased bone volume caused by a decreased number of osteoclasts. Overexpression of Sirt6 led to an increase in osteoclast formation, and Sirt6-deficient osteoclast precursor cells did not undergo osteoclast differentiation efficiently. Moreover, we showed that Sirt6, induced by RANKL-dependent NFATc1 expression, forms a complex with B lymphocyte-induced maturation protein-1 (Blimp1) to negatively regulate expression of anti-osteoclastogenic gene such as Mafb. These findings identify Sirt6 as a novel regulator of osteoclastogenesis by acting as a transcriptional repressor. PMID:27189179

  9. Sirt6 cooperates with Blimp1 to positively regulate osteoclast differentiation

    PubMed Central

    Park, So Jeong; Huh, Jeong-Eun; Shin, Jihye; Park, Doo Ri; Ko, Ryeojin; Jin, Gyu-Rin; Seo, Dong-Hyun; Kim, Han-Sung; Shin, Hong-In; Oh, Goo Taeg; Kim, Hyun Seok; Lee, Soo Young

    2016-01-01

    Global deletion of the gene encoding a nuclear histone deacetylase sirtuin 6 (Sirt6) in mice leads to osteopenia with a low bone turnover due to impaired bone formation. But whether Sirt6 regulates osteoclast differentiation is less clear. Here we show that Sirt6 functions as a transcriptional regulator to directly repress anti-osteoclastogenic gene expression. Targeted ablation of Sirt6 in hematopoietic cells including osteoclast precursors resulted in increased bone volume caused by a decreased number of osteoclasts. Overexpression of Sirt6 led to an increase in osteoclast formation, and Sirt6-deficient osteoclast precursor cells did not undergo osteoclast differentiation efficiently. Moreover, we showed that Sirt6, induced by RANKL-dependent NFATc1 expression, forms a complex with B lymphocyte-induced maturation protein-1 (Blimp1) to negatively regulate expression of anti-osteoclastogenic gene such as Mafb. These findings identify Sirt6 as a novel regulator of osteoclastogenesis by acting as a transcriptional repressor. PMID:27189179

  10. Two populations of Thy1-positive mesenchymal cells regulate in vitro maturation of hepatic progenitor cells.

    PubMed

    Kamo, Naoko; Yasuchika, Kentaro; Fujii, Hideaki; Hoppo, Toshitaka; Machimoto, Takafumi; Ishii, Takamichi; Fujita, Naoya; Tsuruo, Takashi; Yamashita, Jun K; Kubo, Hajime; Ikai, Iwao

    2007-02-01

    We previously reported that the in vitro maturation of CD49f(+)Thy1(-)CD45(-) (CD49f positive) fetal hepatic progenitor cells (HPCs) is supported by Thy1-positive mesenchymal cells derived from the fetal liver. These mesenchymal cell preparations contain two populations, one of a cuboidal shape and the other spindle shaped in morphology. In this study, we determined that the mucin-type transmembrane glycoprotein gp38 could distinguish cuboidal cells from spindle cells by immunocytochemistry. RT-PCR analysis revealed differences between isolated CD49f(+/-)Thy1(+)gp38(+)CD45(-) (gp38 positive) cells and CD49f(+/-)Thy1(+)gp38(-)CD45(-) (gp38 negative) cells, whereas both cells expressed mesenchymal cell markers. The coculture with gp38-positive cells promoted the maturation of CD49f-positive HPCs, which was estimated by positivity for periodic acid-Schiff (PAS) staining, whereas the coculture with gp38-negative cells maintained CD49f-positive HPCs negative for PAS staining. The expression of mature hepatocyte markers, such as tyrosine aminotransferase, tryptophan-2,3-dioxygenase, and glucose-6-phosphatase, were upregulated on HPCs by coculture with gp38-positive cells. Furthermore, transmission electron microscopy revealed the acquisition of mature hepatocyte features by HPCs cocultured with gp38-positive cells. This effect on maturation of HPCs was inhibited by the addition of conditioned medium derived from gp38-negative cells. By contrast, the upregulation of bromodeoxyuridine incorporation by HPCs demonstrated the proliferative effect of coculture with gp38-negative cells. In conclusion, these results suggest that in vitro maturation of HPCs promoted by gp38-positive cells may be opposed by an inhibitory effect of gp38-negative cells, which likely maintain the immature, proliferative state of HPCs. PMID:16990447

  11. Gem GTPase acts upstream Gmip/RhoA to regulate cortical actin remodeling and spindle positioning during early mitosis.

    PubMed

    Andrieu, Guillaume; Quaranta, Muriel; Leprince, Corinne; Cuvillier, Olivier; Hatzoglou, Anastassia

    2014-11-01

    Gem is a small guanosine triphosphate (GTP)-binding protein within the Ras superfamily, involved in the regulation of voltage-gated calcium channel activity and cytoskeleton reorganization. Gem overexpression leads to stress fiber disruption, actin and cell shape remodeling and neurite elongation in interphase cells. In this study, we show that Gem plays a crucial role in the regulation of cortical actin cytoskeleton that undergoes active remodeling during mitosis. Ectopic expression of Gem leads to cortical actin disruption and spindle mispositioning during metaphase. The regulation of spindle positioning by Gem involves its downstream effector Gmip. Knockdown of Gmip rescued Gem-induced spindle phenotype, although both Gem and Gmip accumulated at the cell cortex. In addition, we implicated RhoA GTPase as an important effector of Gem/Gmip signaling. Inactivation of RhoA by overexpressing dominant-negative mutant prevented normal spindle positioning. Introduction of active RhoA rescued the actin and spindle positioning defects caused by Gem or Gmip overexpression. These findings demonstrate a new role of Gem/Gmip/RhoA signaling in cortical actin regulation during early mitotic stages. PMID:25173885

  12. Positive and negative peer interaction in 3- and 4-year-olds in relation to regulation and dysregulation.

    PubMed

    Ramani, Geetha B; Brownell, Celia A; Campbell, Susan B

    2010-01-01

    Using a sample from the NICHD Study of Early Child Care (N = 435; 219 girls), the authors derived several measures of regulation and dysregulation that predicted, both concurrently and longitudinally, children's positive and negative peer interactions in multiple contexts. Observers rated peer interactions in child care and during dyadic play with a friend, and mothers rated peer behavior. The authors based the derived measures on resistance to temptation (36 months) and delay of gratification (54 months) tasks, as well as observations in child care of children's compliance and defiance with adults at both ages and maternal reports. Preschoolers who had better impulse control and who were more compliant and less defiant with adults engaged more often in friendly, positive, peer play and were less negative in their peer play across contexts. Associations between regulation and dysregulation and peer interaction were broader and more consistent at 54 months than at 36 months. Longitudinally, regulation at 36 months was only modestly associated with more positive and less negative peer play at 54 months. The authors discuss findings in the context of developing self-regulation and its importance for early peer relationships. PMID:20836431

  13. Counter-regulating on the Internet: Threat elicits preferential processing of positive information.

    PubMed

    Greving, Hannah; Sassenberg, Kai; Fetterman, Adam

    2015-09-01

    The Internet is a central source of information. It is increasingly used for information search in self-relevant domains (e.g., health). Self-relevant topics are also associated with specific emotions and motivational states. For example, individuals may fear serious illness and feel threatened. Thus far, the impact of threat has received little attention in Internet-based research. The current studies investigated how threat influences Internet search. Threat is known to elicit the preferential processing of positive information. The self-directed nature of Internet search should particularly provide opportunities for such processing behavior. We predicted that during Internet search, more positive information would be processed (i.e., allocated more attention to) and more positive knowledge would be acquired under threat than in a control condition. Three experiments supported this prediction: Under threat, attention is directed more to positive web pages (Study 1) and positive links (Study 2), and more positive information is acquired (Studies 1 and 3) than in a control condition. Notably, the effect on knowledge acquisition was mediated by the effect on attention allocation during an actual Internet search (Study 1). Thus, Internet search under threat leads to selective processing of positive information and dampens threatened individuals' negative affect. PMID:26098968

  14. Mahogunin-mediated regulation of Gαi localisation during mitosis and its effect on spindle positioning.

    PubMed

    Srivastava, Devika; Mukherjee, Rukmini; Mookherjee, Debdatto; Chakrabarti, Oishee

    2016-08-01

    Mahogunin RING Finger 1 (MGRN1) is a ubiquitin E3 ligase known to affect spindle tilt in mitotic cells by regulating α-tubulin ubiquitination and polymerization. In cell culture systems we have found that expressing truncated mutants of MGRN1 leads to various other mitotic anomalies, such as lateral and angular spindle displacements. This seems to be independent of the MGRN1 ligase activity. Our experiments suggest that MGRN1 regulates the balance between the lower molecular weight monomeric Gαi and larger trimeric G-protein complex, along with its abundance in the ternary complex that regulates spindle positioning. The cytosolic isoforms of MGRN1 lead to the enrichment of monomeric Gαi in the cytosol and its subsequent recruitment at the plasma membrane. Excess Gαi at the cell cortex results in an imbalance in the assembly of the ternary complex regulating spindle positioning during mitosis. These observations seem independent of the ligase activity of MGRN1, although we cannot exclude the involvement of an intermediate player that acts as a substrate for MGRN1, and in turn, regulates Gαi. PMID:27471821

  15. Colorectal cancer-related mutant KRAS alleles function as positive regulators of autophagy

    PubMed Central

    Alves, Sara; Castro, Lisandra; Fernandes, Maria Sofia; Francisco, Rita; Castro, Paula; Priault, Muriel; Chaves, Susana Rodrigues; Moyer, Mary Pat; Oliveira, Carla; Seruca, Raquel; Côrte-Real, Manuela

    2015-01-01

    The recent interest to modulate autophagy in cancer therapy has been hampered by the dual roles of this conserved catabolic process in cancer, highlighting the need for tailored approaches. Since RAS isoforms have been implicated in autophagy regulation and mutation of the KRAS oncogene is highly frequent in colorectal cancer (CRC), we questioned whether/how mutant KRAS alleles regulate autophagy in CRC and its implications. We established two original models, KRAS-humanized yeast and KRAS-non-cancer colon cells and showed that expression of mutated KRAS up-regulates starvation-induced autophagy in both. Accordingly, KRAS down-regulation inhibited autophagy in CRC-derived cells harboring KRAS mutations. We further show that KRAS-induced autophagy proceeds via up-regulation of the MEK/ERK pathway in both colon models and that KRAS and autophagy contribute to CRC cell survival during starvation. Since KRAS inhibitors have proven difficult to develop, our results suggest using autophagy inhibitors as a combined/alternative therapeutic approach in CRCs with mutant KRAS. PMID:26418750

  16. Effete, a Drosophila Chromatin-Associated Ubiquitin-Conjugating Enzyme That Affects Telomeric and Heterochromatic Position Effect Variegation

    PubMed Central

    Cipressa, Francesca; Romano, Sabrina; Centonze, Silvia; zur Lage, Petra I.; Vernì, Fiammetta; Dimitri, Patrizio; Gatti, Maurizio; Cenci, Giovanni

    2013-01-01

    Drosophila telomeres are elongated by the transposition of telomere-specific retrotransposons rather than telomerase activity. Proximal to the terminal transposon array, Drosophila chromosomes contain several kilobases of a complex satellite DNA termed telomere-associated sequences (TASs). Reporter genes inserted into or next to the TAS are silenced through a mechanism called telomere position effect (TPE). TPE is reminiscent of the position effect variegation (PEV) induced by Drosophila constitutive heterochromatin. However, most genes that modulate PEV have no effect on TPE, and systematic searches for TPE modifiers have so far identified only a few dominant suppressors. Surprisingly, only a few of the genes required to prevent telomere fusion have been tested for their effect on TPE. Here, we show that with the exception of the effete (eff; also called UbcD1) mutant alleles, none of the tested mutations at the other telomere fusion genes affects TPE. We also found that mutations in eff, which encodes a class I ubiquitin-conjugating enzyme, act as suppressors of PEV. Thus, eff is one of the rare genes that can modulate both TPE and PEV. Immunolocalization experiments showed that Eff is a major constituent of polytene chromosomes. Eff is enriched at several euchromatic bands and interbands, the TAS regions, and the chromocenter. Our results suggest that Eff associates with different types of chromatin affecting their abilities to regulate gene expression. PMID:23821599

  17. Hope, Self-Esteem, and Self-Regulation: Positive Characteristics among Men and Women in Recovery

    ERIC Educational Resources Information Center

    Ferrari, Joseph R.; Stevens, Edward B.; Legler, Raymond; Jason, Leonard A.

    2012-01-01

    Hopefulness remains unclear in relation to aspects of self-control and self-esteem among adults in substance abuse recovery. The present study explored the relationship between dispositional hope (agency and pathway) with self-esteem (self-liking, self-competency, and self-confidence) and self-regulation (impulse control and self-discipline),…

  18. The Pro-apoptotic STK38 Kinase Is a New Beclin1 Partner Positively Regulating Autophagy.

    PubMed

    Joffre, Carine; Dupont, Nicolas; Hoa, Lily; Gomez, Valenti; Pardo, Raul; Gonçalves-Pimentel, Catarina; Achard, Pauline; Bettoun, Audrey; Meunier, Brigitte; Bauvy, Chantal; Cascone, Ilaria; Codogno, Patrice; Fanto, Manolis; Hergovich, Alexander; Camonis, Jacques

    2015-10-01

    Autophagy plays key roles in development, oncogenesis, cardiovascular, metabolic, and neurodegenerative diseases. Hence, understanding how autophagy is regulated can reveal opportunities to modify autophagy in a disease-relevant manner. Ideally, one would want to functionally define autophagy regulators whose enzymatic activity can potentially be modulated. Here, we describe the STK38 protein kinase (also termed NDR1) as a conserved regulator of autophagy. Using STK38 as bait in yeast-two-hybrid screens, we discovered STK38 as a novel binding partner of Beclin1, a key regulator of autophagy. By combining molecular, cell biological, and genetic approaches, we show that STK38 promotes autophagosome formation in human cells and in Drosophila. Upon autophagy induction, STK38-depleted cells display impaired LC3B-II conversion; reduced ATG14L, ATG12, and WIPI-1 puncta formation; and significantly decreased Vps34 activity, as judged by PI3P formation. Furthermore, we observed that STK38 supports the interaction of the exocyst component Exo84 with Beclin1 and RalB, which is required to initiate autophagosome formation. Upon studying the activation of STK38 during autophagy induction, we found that STK38 is stimulated in a MOB1- and exocyst-dependent manner. In contrast, RalB depletion triggers hyperactivation of STK38, resulting in STK38-dependent apoptosis under prolonged autophagy conditions. Together, our data establish STK38 as a conserved regulator of autophagy in human cells and flies. We also provide evidence demonstrating that STK38 and RalB assist the coordination between autophagic and apoptotic events upon autophagy induction, hence further proposing a role for STK38 in determining cellular fate in response to autophagic conditions. PMID:26387716

  19. The Pro-apoptotic STK38 Kinase Is a New Beclin1 Partner Positively Regulating Autophagy

    PubMed Central

    Joffre, Carine; Dupont, Nicolas; Hoa, Lily; Gomez, Valenti; Pardo, Raul; Gonçalves-Pimentel, Catarina; Achard, Pauline; Bettoun, Audrey; Meunier, Brigitte; Bauvy, Chantal; Cascone, Ilaria; Codogno, Patrice; Fanto, Manolis; Hergovich, Alexander; Camonis, Jacques

    2015-01-01

    Summary Autophagy plays key roles in development, oncogenesis, cardiovascular, metabolic, and neurodegenerative diseases. Hence, understanding how autophagy is regulated can reveal opportunities to modify autophagy in a disease-relevant manner. Ideally, one would want to functionally define autophagy regulators whose enzymatic activity can potentially be modulated. Here, we describe the STK38 protein kinase (also termed NDR1) as a conserved regulator of autophagy. Using STK38 as bait in yeast-two-hybrid screens, we discovered STK38 as a novel binding partner of Beclin1, a key regulator of autophagy. By combining molecular, cell biological, and genetic approaches, we show that STK38 promotes autophagosome formation in human cells and in Drosophila. Upon autophagy induction, STK38-depleted cells display impaired LC3B-II conversion; reduced ATG14L, ATG12, and WIPI-1 puncta formation; and significantly decreased Vps34 activity, as judged by PI3P formation. Furthermore, we observed that STK38 supports the interaction of the exocyst component Exo84 with Beclin1 and RalB, which is required to initiate autophagosome formation. Upon studying the activation of STK38 during autophagy induction, we found that STK38 is stimulated in a MOB1- and exocyst-dependent manner. In contrast, RalB depletion triggers hyperactivation of STK38, resulting in STK38-dependent apoptosis under prolonged autophagy conditions. Together, our data establish STK38 as a conserved regulator of autophagy in human cells and flies. We also provide evidence demonstrating that STK38 and RalB assist the coordination between autophagic and apoptotic events upon autophagy induction, hence further proposing a role for STK38 in determining cellular fate in response to autophagic conditions. PMID:26387716

  20. CoREST acts as a positive regulator of Notch signaling in the follicle cells of Drosophila melanogaster

    PubMed Central

    Domanitskaya, Elena; Schüpbach, Trudi

    2012-01-01

    The Notch signaling pathway plays important roles in a variety of developmental events. The context-dependent activities of positive and negative modulators dramatically increase the diversity of cellular responses to Notch signaling. In a screen for mutations affecting the Drosophila melanogaster follicular epithelium, we isolated a mutation in CoREST that disrupts the Notch-dependent mitotic-to-endocycle switch of follicle cells at stage 6 of oogenesis. We show that Drosophila CoREST positively regulates Notch signaling, acting downstream of the proteolytic cleavage of Notch but upstream of Hindsight activity; the Hindsight gene is a Notch target that coordinates responses in the follicle cells. We show that CoREST genetically interacts with components of the Notch repressor complex, Hairless, C-terminal Binding Protein and Groucho. In addition, we demonstrate that levels of H3K27me3 and H4K16 acetylation are dramatically increased in CoREST mutant follicle cells. Our data indicate that CoREST acts as a positive modulator of the Notch pathway in the follicular epithelium as well as in wing tissue, and suggests a previously unidentified role for CoREST in the regulation of Notch signaling. Given its high degree of conservation among species, CoREST probably also functions as a regulator of Notch-dependent cellular events in other organisms. PMID:22331351

  1. Roles of fkbN in Positive Regulation and tcs7 in Negative Regulation of FK506 Biosynthesis in Streptomyces sp. Strain KCTC 11604BP

    PubMed Central

    Mo, SangJoon; Yoo, Young Ji; Ban, Yeon Hee; Lee, Sung-Kwon; Kim, Eunji

    2012-01-01

    FK506 is an important 23-member polyketide macrolide with immunosuppressant activity. Its entire biosynthetic gene cluster was previously cloned from Streptomyces sp. strain KCTC 11604BP, and sequence analysis identified three putative regulatory genes, tcs2, tcs7, and fkbN, which encode proteins with high similarity to the AsnC family transcriptional regulators, LysR-type transcriptional regulators, and LAL family transcriptional regulators, respectively. Overexpression and in-frame deletion of tcs2 did not affect the production of FK506 or co-occurring FK520 compared to results for the wild-type strain, suggesting that tcs2 is not involved in their biosynthesis. fkbN overexpression improved the levels of FK506 and FK520 production by approximately 2.0-fold, and a deletion of fkbN caused the complete loss of FK506 and FK520 production. Although the overexpression of tcs7 decreased the levels of FK506 and FK520 production slightly, a deletion of tcs7 caused 1.9-fold and 1.5-fold increases in FK506 and FK520 production, respectively. Finally, fkbN overexpression in the tcs7 deletion strain resulted in a 4.0-fold (21 mg liter−1) increase in FK506 production compared to that by the wild-type strain. This suggests that fkbN encodes a positive regulatory protein essential for FK506/FK520 biosynthesis and that the gene product of tcs7 negatively regulates their biosynthesis, demonstrating the potential of exploiting this information for strain improvement. Semiquantitative reverse transcription-PCR (RT-PCR) analyses of the transcription levels of the FK506 biosynthetic genes in the wild-type and mutant strains proved that most of the FK506 biosynthetic genes are regulated by fkbN in a positive manner and negatively by tcs7. PMID:22267670

  2. 77 FR 35879 - Defense Federal Acquisition Regulation Supplement: Title 41 Positive Law Codification-Further...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-06-15

    ... Register at 76 FR 78874 on December 20, 2011. The comment period closed on February 21, 2012. One... rule published at 76 FR 78874 on December 20, 2011, invited comments from small businesses and other...: Title 41 Positive Law Codification--Further Implementation (DFARS Case 2012- D003) AGENCY:...

  3. Chitinase Expression in Listeria monocytogenes Is Positively Regulated by the Agr System

    PubMed Central

    Paspaliari, Dafni Katerina; Mollerup, Maria Storm; Kallipolitis, Birgitte H.; Ingmer, Hanne; Larsen, Marianne Halberg

    2014-01-01

    The food-borne pathogen Listeria monocytogenes encodes two chitinases, ChiA and ChiB, which allow the bacterium to hydrolyze chitin, the second most abundant polysaccharide in nature. Intriguingly, despite the absence of chitin in human and mammalian hosts, both of the chitinases have been deemed important for infection, through a mechanism that, at least in the case of ChiA, involves modulation of host immune responses. In this study, we show that the expression of the two chitinases is subject to regulation by the listerial agr system, a homologue of the agr quorum-sensing system of Staphylococcus aureus, that has so far been implicated in virulence and biofilm formation. We demonstrate that in addition to these roles, the listerial agr system is required for efficient chitin hydrolysis, as deletion of agrD, encoding the putative precursor of the agr autoinducer, dramatically decreased chitinolytic activity on agar plates. Agr was specifically induced in response to chitin addition in stationary phase and agrD was found to regulate the amount of chiA, but not chiB, transcripts. Although the transcript levels of chiB did not depend on agrD, the extracellular protein levels of both chitinases were reduced in the ΔagrD mutant. The regulatory effect of agr on chiA is potentially mediated through the small RNA LhrA, which we show here to be negatively regulated by agr. LhrA is in turn known to repress chiA translation by binding to the chiA transcript and interfering with ribosome recruitment. Our results highlight a previously unrecognized role of the agr system and suggest that autoinducer-based regulation of chitinolytic systems may be more commonplace than previously thought. PMID:24752234

  4. TOR complex 2-Ypk1 signaling is an essential positive regulator of the general amino acid control response and autophagy.

    PubMed

    Vlahakis, Ariadne; Graef, Martin; Nunnari, Jodi; Powers, Ted

    2014-07-22

    The highly conserved Target of Rapamycin (TOR) kinase is a central regulator of cell growth and metabolism in response to nutrient availability. TOR functions in two structurally and functionally distinct complexes, TOR Complex 1 (TORC1) and TOR Complex 2 (TORC2). Through TORC1, TOR negatively regulates autophagy, a conserved process that functions in quality control and cellular homeostasis and, in this capacity, is part of an adaptive nutrient deprivation response. Here we demonstrate that during amino acid starvation TOR also operates independently as a positive regulator of autophagy through the conserved TORC2 and its downstream target protein kinase, Ypk1. Under these conditions, TORC2-Ypk1 signaling negatively regulates the Ca(2+)/calmodulin-dependent phosphatase, calcineurin, to enable the activation of the amino acid-sensing eIF2α kinase, Gcn2, and to promote autophagy. Our work reveals that the TORC2 pathway regulates autophagy in an opposing manner to TORC1 to provide a tunable response to cellular metabolic status. PMID:25002487

  5. Auxin Regulates the Initiation and Radial Position of Plant Lateral Organs

    PubMed Central

    Reinhardt, Didier; Mandel, Therese; Kuhlemeier, Cris

    2000-01-01

    Leaves originate from the shoot apical meristem, a small mound of undifferentiated tissue at the tip of the stem. Leaf formation begins with the selection of a group of founder cells in the so-called peripheral zone at the flank of the meristem, followed by the initiation of local growth and finally morphogenesis of the resulting bulge into a differentiated leaf. Whereas the mechanisms controlling the switch between meristem propagation and leaf initiation are being identified by genetic and molecular analyses, the radial positioning of leaves, known as phyllotaxis, remains poorly understood. Hormones, especially auxin and gibberellin, are known to influence phyllotaxis, but their specific role in the determination of organ position is not clear. We show that inhibition of polar auxin transport blocks leaf formation at the vegetative tomato meristem, resulting in pinlike naked stems with an intact meristem at the tip. Microapplication of the natural auxin indole-3-acetic acid (IAA) to the apex of such pins restores leaf formation. Similarly, exogenous IAA induces flower formation on Arabidopsis pin-formed1-1 inflorescence apices, which are blocked in flower formation because of a mutation in a putative auxin transport protein. Our results show that auxin is required for and sufficient to induce organogenesis both in the vegetative tomato meristem and in the Arabidopsis inflorescence meristem. In this study, organogenesis always strictly coincided with the site of IAA application in the radial dimension, whereas in the apical–basal dimension, organ formation always occurred at a fixed distance from the summit of the meristem. We propose that auxin determines the radial position and the size of lateral organs but not the apical–basal position or the identity of the induced structures. PMID:10760240

  6. Cyclin G Functions as a Positive Regulator of Growth and Metabolism in Drosophila.

    PubMed

    Fischer, Patrick; La Rosa, Martina K; Schulz, Adriana; Preiss, Anette; Nagel, Anja C

    2015-08-01

    In multicellular organisms, growth and proliferation is adjusted to nutritional conditions by a complex signaling network. The Insulin receptor/target of rapamycin (InR/TOR) signaling cascade plays a pivotal role in nutrient dependent growth regulation in Drosophila and mammals alike. Here we identify Cyclin G (CycG) as a regulator of growth and metabolism in Drosophila. CycG mutants have a reduced body size and weight and show signs of starvation accompanied by a disturbed fat metabolism. InR/TOR signaling activity is impaired in cycG mutants, combined with a reduced phosphorylation status of the kinase Akt1 and the downstream factors S6-kinase and eukaryotic translation initiation factor 4E binding protein (4E-BP). Moreover, the expression and accumulation of Drosophila insulin like peptides (dILPs) is disturbed in cycG mutant brains. Using a reporter assay, we show that the activity of one of the first effectors of InR signaling, Phosphoinositide 3-kinase (PI3K92E), is unaffected in cycG mutants. However, the metabolic defects and weight loss in cycG mutants were rescued by overexpression of Akt1 specifically in the fat body and by mutants in widerborst (wdb), the B'-subunit of the phosphatase PP2A, known to downregulate Akt1 by dephosphorylation. Together, our data suggest that CycG acts at the level of Akt1 to regulate growth and metabolism via PP2A in Drosophila. PMID:26274446

  7. BMP-2 Induced Expression of PLCβ1 That is a Positive Regulator of Osteoblast Differentiation.

    PubMed

    Ramazzotti, Giulia; Bavelloni, Alberto; Blalock, William; Piazzi, Manuela; Cocco, Lucio; Faenza, Irene

    2016-03-01

    Bone morphogenetic protein 2 (BMP-2) is a critical growth factor that directs osteoblast differentiation and bone formation. Phosphoinositide-phospholipase Cβ 1 (PLCβ1) plays a crucial role in the initiation of the genetic program responsible for muscle differentiation. Differentiation of C2C12 mouse myoblasts in response to insulin stimulation is characterized by a marked increase in nuclear PLCβ1. Here, the function of PLCβ1 in the osteogenic differentiation was investigated. Briefly, in C2C12 cells treated with BMP-2 we assist to a remarkable increase in PLCβ1 protein and mRNA expression. The data regarding the influence on differentiation demonstrated that PLCβ1 promotes osteogenic differentiation by up-regulating alkaline phosphatase (ALP). Moreover, PLCβ1 is present in the nuclear compartment of these cells and overexpression of a cytosolic-PLCβ1mutant (cyt-PLCβ1), which lacks a nuclear localization sequence, prevented the differentiation of C2C12 cells into osteocytes. Recent evidence indicates that miRNAs act as important post transcriptional regulators in a large number of processes, including osteoblast differentiation. Since miR-214 is a regulator of Osterix (Osx) which is an osteoblast-specific transcription factor that is needful for osteoblast differentiation and bone formation, we further investigated whether PLCβ1 could be a potential target of miR-214 in the control of osteogenic differentiation by gain- and loss- of function experiment. The results indicated that inhibition of miR-214 in C2C12 cells significantly enhances the protein level of PLCβ1 and promotes C2C12 BMP-2-induced osteogenesis by targeting PLCβ1. PMID:26217938

  8. Positive correlation between ADAR expression and its targets suggests a complex regulation mediated by RNA editing in the human brain

    PubMed Central

    Liscovitch, Noa; Bazak, Lily; Levanon, Erez Y; Chechik, Gal

    2014-01-01

    A-to-I RNA editing by adenosine deaminases acting on RNA is a post-transcriptional modification that is crucial for normal life and development in vertebrates. RNA editing has been shown to be very abundant in the human transcriptome, specifically at the primate-specific Alu elements. The functional role of this wide-spread effect is still not clear; it is believed that editing of transcripts is a mechanism for their down-regulation via processes such as nuclear retention or RNA degradation. Here we combine 2 neural gene expression datasets with genome-level editing information to examine the relation between the expression of ADAR genes with the expression of their target genes. Specifically, we computed the spatial correlation across structures of post-mortem human brains between ADAR and a large set of targets that were found to be edited in their Alu repeats. Surprisingly, we found that a large fraction of the edited genes are positively correlated with ADAR, opposing the assumption that editing would reduce expression. When considering the correlations between ADAR and its targets over development, 2 gene subsets emerge, positively correlated and negatively correlated with ADAR expression. Specifically, in embryonic time points, ADAR is positively correlated with many genes related to RNA processing and regulation of gene expression. These findings imply that the suggested mechanism of regulation of expression by editing is probably not a global one; ADAR expression does not have a genome wide effect reducing the expression of editing targets. It is possible, however, that RNA editing by ADAR in non-coding regions of the gene might be a part of a more complex expression regulation mechanism. PMID:25692240

  9. Positive correlation between ADAR expression and its targets suggests a complex regulation mediated by RNA editing in the human brain.

    PubMed

    Liscovitch, Noa; Bazak, Lily; Levanon, Erez Y; Chechik, Gal

    2014-01-01

    A-to-I RNA editing by adenosine deaminases acting on RNA is a post-transcriptional modification that is crucial for normal life and development in vertebrates. RNA editing has been shown to be very abundant in the human transcriptome, specifically at the primate-specific Alu elements. The functional role of this wide-spread effect is still not clear; it is believed that editing of transcripts is a mechanism for their down-regulation via processes such as nuclear retention or RNA degradation. Here we combine 2 neural gene expression datasets with genome-level editing information to examine the relation between the expression of ADAR genes with the expression of their target genes. Specifically, we computed the spatial correlation across structures of post-mortem human brains between ADAR and a large set of targets that were found to be edited in their Alu repeats. Surprisingly, we found that a large fraction of the edited genes are positively correlated with ADAR, opposing the assumption that editing would reduce expression. When considering the correlations between ADAR and its targets over development, 2 gene subsets emerge, positively correlated and negatively correlated with ADAR expression. Specifically, in embryonic time points, ADAR is positively correlated with many genes related to RNA processing and regulation of gene expression. These findings imply that the suggested mechanism of regulation of expression by editing is probably not a global one; ADAR expression does not have a genome wide effect reducing the expression of editing targets. It is possible, however, that RNA editing by ADAR in non-coding regions of the gene might be a part of a more complex expression regulation mechanism. PMID:25692240

  10. LPXRFa, the piscine ortholog of GnIH, and LPXRF receptor positively regulate gonadotropin secretion in Tilapia (Oreochromis niloticus).

    PubMed

    Biran, Jakob; Golan, Matan; Mizrahi, Naama; Ogawa, Satoshi; Parhar, Ishwar S; Levavi-Sivan, Berta

    2014-11-01

    LPXRFamide (LPXRFa) peptides have been characterized for their ability to inhibit gonadotropin (GTH) release in birds and stimulate growth hormone (GH) release in frogs. However, their involvement in regulating the reproductive hypothalamo-pituitary-gonadal axis in mammals and fish is inconclusive. To study the role of LPXRFa peptides in the regulation of GTH secretion, we cloned tilapia LPXRFa and LPXRF receptor (LPXRF-R). Processing of the tilapia preproLPXRFa liberated three mature LPXRFa peptides that varied in size and post-translational modifications. Phylogenetic analysis of LPXRFa and the closely related RFamide peptide PQRFa showed clear clustering of each peptide sequence with its orthologs from various vertebrates. Signal-transduction analysis of the tilapia LPXRF-R in COS-7 cells showed clear stimulation of CRE-dependent luciferase activity, whereas the human NPFFR1 showed suppression of forskolin-induced CRE-dependent activity in this system. Administration of the tilapia pyroglutaminated LPXRFa-2 peptide to primary cell culture of tilapia pituitaries, or to reproductive female tilapia by ip injection, positively regulated both LH and FSH release in vivo and in vitro. Using double-labeled fluorescent in-situ hybridization and immunofluorescence, βLH cells were found to co-express both tilapia lpxrf and tilapia lpxrf-r mRNA, whereas some of the βFSH cells coexpressed only lpxrf-r mRNA. No coexpression of tilapia lpxrf-r was identified in GH-positive cells. These findings suggest that the LPXRFa system is a potent positive regulator of the reproductive neuroendocrine axis of tilapia. PMID:25144920

  11. A Review of Selected Blood-Borne Pathogen Position Statements and Federal Regulations

    PubMed Central

    Arnold, Brent L.

    1995-01-01

    One response to the AIDS epidemic has been the formation of blood-borne pathogen policy statements by medical associations, athletic governing bodies, and the federal government. The policy statements by medical associations and athletic governing bodies discuss a wide range of issues, including the eligibility of infected athletes and the right of infected health care workers to practice. In contrast, federal regulations are limited to employees in the work environment. Despite the apparent comprehensiveness of these documents, major deficiencies in the documents do exist. For example, employees exposed to body fluids are entitled to free, employer-provided HIV testing. Similarly, athletes exposed to body fluids also are entitled to voluntary HIV testing. However, it is unclear who should pay for this testing. Furthermore, AIDS testing of student athletic trainers is never discussed. Although there are deficiencies, these documents provide guidelines for resolving the deficiencies. For example, because student athletic trainers act as employees of their institution, it is reasonable to suggest that they receive the same protections that federal regulations provide to employees. Thus, the athletic trainer should find these documents useful for developing policies related to blood-borne pathogens. PMID:16558331

  12. The transcription factor Pitx2 positions the embryonic axis and regulates twinning

    PubMed Central

    Torlopp, Angela; Khan, Mohsin A F; Oliveira, Nidia M M; Lekk, Ingrid; Soto-Jiménez, Luz Mayela; Sosinsky, Alona; Stern, Claudio D

    2014-01-01

    Embryonic polarity of invertebrates, amphibians and fish is specified largely by maternal determinants, which fixes cell fates early in development. In contrast, amniote embryos remain plastic and can form multiple individuals until gastrulation. How is their polarity determined? In the chick embryo, the earliest known factor is cVg1 (homologous to mammalian growth differentiation factor 1, GDF1), a transforming growth factor beta (TGFβ) signal expressed posteriorly before gastrulation. A molecular screen to find upstream regulators of cVg1 in normal embryos and in embryos manipulated to form twins now uncovers the transcription factor Pitx2 as a candidate. We show that Pitx2 is essential for axis formation, and that it acts as a direct regulator of cVg1 expression by binding to enhancers within neighbouring genes. Pitx2, Vg1/GDF1 and Nodal are also key actors in left–right asymmetry, suggesting that the same ancient polarity determination mechanism has been co-opted to different functions during evolution. DOI: http://dx.doi.org/10.7554/eLife.03743.001 PMID:25496870

  13. HOPE, SELF-ESTEEM, AND SELF-REGULATION: POSITIVE CHARACTERISTICS AMONG MEN AND WOMEN IN RECOVERY

    PubMed Central

    Ferrari, Joseph R.; Stevens, Edward B.; Legler, Raymond; Jason, Leonard A.

    2014-01-01

    Hopefulness remains unclear in relation to aspects of self-control and self-esteem among adults in substance abuse recovery. The present study explored the relationship between dispositional hope (agency and pathway) with self-esteem (self-liking, self-competency, and self-confidence) and self-regulation (impulse control and self-discipline), using a latent variable measurement model and structural equation modeling among adults (n = 601) residing in a communal living setting for persons in substance abuse recovery. Results showed that multiple dimensions of these constructs were significant as individual predictors. With persons in recovery, self-regulation included impulsivity control and self-discipline, while self-esteem reflected self-liking, competence, and a sense of self-confidence. Furthermore, both hope-pathways and hope-agency significantly related to self-control/impulse control but not self-control/discipline, and self-esteem/competency was associated with hope-pathways but not hope-agency. PMID:25382880

  14. The transcription factor Pitx2 positions the embryonic axis and regulates twinning.

    PubMed

    Torlopp, Angela; Khan, Mohsin A F; Oliveira, Nidia M M; Lekk, Ingrid; Soto-Jiménez, Luz Mayela; Sosinsky, Alona; Stern, Claudio D

    2014-01-01

    Embryonic polarity of invertebrates, amphibians and fish is specified largely by maternal determinants, which fixes cell fates early in development. In contrast, amniote embryos remain plastic and can form multiple individuals until gastrulation. How is their polarity determined? In the chick embryo, the earliest known factor is cVg1 (homologous to mammalian growth differentiation factor 1, GDF1), a transforming growth factor beta (TGFβ) signal expressed posteriorly before gastrulation. A molecular screen to find upstream regulators of cVg1 in normal embryos and in embryos manipulated to form twins now uncovers the transcription factor Pitx2 as a candidate. We show that Pitx2 is essential for axis formation, and that it acts as a direct regulator of cVg1 expression by binding to enhancers within neighbouring genes. Pitx2, Vg1/GDF1 and Nodal are also key actors in left-right asymmetry, suggesting that the same ancient polarity determination mechanism has been co-opted to different functions during evolution. PMID:25496870

  15. The NAC transcription factor ANAC046 is a positive regulator of chlorophyll degradation and senescence in Arabidopsis leaves

    PubMed Central

    Oda-Yamamizo, Chihiro; Mitsuda, Nobutaka; Sakamoto, Shingo; Ogawa, Daisuke; Ohme-Takagi, Masaru; Ohmiya, Akemi

    2016-01-01

    Chlorophyll (Chl) degradation occurs during leaf senescence, embryo degreening, bud breaking, and fruit ripening. The Chl catabolic pathway has been intensively studied and nearly all the enzymes involved are identified and characterized; however, the molecular regulatory mechanisms of this pathway are largely unknown. In this study, we performed yeast one-hybrid screening using a transcription factor cDNA library to search for factors controlling the expression of Chl catabolic genes. We identified ANAC046 as a common regulator that directly binds to the promoter regions of NON-YELLOW COLORING1, STAY-GREEN1 (SGR1), SGR2, and PHEOPHORBIDE a OXYGENASE. Transgenic plants overexpressing ANAC046 exhibited an early-senescence phenotype and a lower Chl content in comparison with the wild-type plants, whereas loss-of-function mutants exhibited a delayed-senescence phenotype and a higher Chl content. Microarray analysis of ANAC046 transgenic plants showed that not only Chl catabolic genes but also senescence-associated genes were positively regulated by ANAC046. We conclude that ANAC046 is a positive regulator of Arabidopsis leaf senescence and exerts its effect by controlling the expression of Chl catabolic genes and senescence-associated genes. PMID:27021284

  16. Transmembrane Adaptor Protein PAG/CBP Is Involved in both Positive and Negative Regulation of Mast Cell Signaling

    PubMed Central

    Draberova, Lubica; Bugajev, Viktor; Potuckova, Lucie; Halova, Ivana; Bambouskova, Monika; Polakovicova, Iva; Xavier, Ramnik J.; Seed, Brian

    2014-01-01

    The transmembrane adaptor protein PAG/CBP (here, PAG) is expressed in multiple cell types. Tyrosine-phosphorylated PAG serves as an anchor for C-terminal SRC kinase, an inhibitor of SRC-family kinases. The role of PAG as a negative regulator of immunoreceptor signaling has been examined in several model systems, but no functions in vivo have been determined. Here, we examined the activation of bone marrow-derived mast cells (BMMCs) with PAG knockout and PAG knockdown and the corresponding controls. Our data show that PAG-deficient BMMCs exhibit impaired antigen-induced degranulation, extracellular calcium uptake, tyrosine phosphorylation of several key signaling proteins (including the high-affinity IgE receptor subunits, spleen tyrosine kinase, and phospholipase C), production of several cytokines and chemokines, and chemotaxis. The enzymatic activities of the LYN and FYN kinases were increased in nonactivated cells, suggesting the involvement of a LYN- and/or a FYN-dependent negative regulatory loop. When BMMCs from PAG-knockout mice were activated via the KIT receptor, enhanced degranulation and tyrosine phosphorylation of the receptor were observed. In vivo experiments showed that PAG is a positive regulator of passive systemic anaphylaxis. The combined data indicate that PAG can function as both a positive and a negative regulator of mast cell signaling, depending upon the signaling pathway involved. PMID:25246632

  17. The 14-3-3 protein PAR-5 regulates the asymmetric localization of the LET-99 spindle positioning protein.

    PubMed

    Wu, Jui-Ching; Espiritu, Eugenel B; Rose, Lesilee S

    2016-04-15

    PAR proteins play important roles in establishing cytoplasmic polarity as well as regulating spindle positioning during asymmetric division. However, the molecular mechanisms by which the PAR proteins generate asymmetry in different cell types are still being elucidated. Previous studies in Caenorhabditis elegans revealed that PAR-3 and PAR-1 regulate the asymmetric localization of LET-99, which in turn controls spindle positioning by affecting the distribution of the conserved force generating complex. In wild-type embryos, LET-99 is localized in a lateral cortical band pattern, via inhibition at the anterior by PAR-3 and at the posterior by PAR-1. In this report, we show that the 14-3-3 protein PAR-5 is also required for cortical LET-99 asymmetry. PAR-5 associated with LET-99 in pull-down assays, and two PAR-5 binding sites were identified in LET-99 using the yeast two-hybrid assay. Mutation of these sites abolished binding in yeast and altered LET-99 localization in vivo: LET-99 was present at the highest levels at the posterior pole of the embryo instead of a band in par-5 embryos. Together the results indicate that PAR-5 acts in a mechanism with PAR-1 to regulate LET-99 cortical localization. PMID:26921457

  18. The ER membrane-anchored ubiquitin ligase Hrd1 is a positive regulator of T-cell immunity

    PubMed Central

    Xu, Yuanming; Zhao, Fang; Qiu, Quan; Chen, Kun; Wei, Juncheng; Kong, Qingfei; Gao, Beixue; Melo-Cardenas, Johanna; Zhang, Bin; Zhang, Jinping; Song, Jianxun; Zhang, Donna D.; Zhang, Jianing; Fan, Yunping; Li, Huabin; Fang, Deyu

    2016-01-01

    Identification of positive regulators of T-cell immunity induced during autoimmune diseases is critical for developing novel therapies. The endoplasmic reticulum resident ubiquitin ligase Hrd1 has recently emerged as a critical regulator of dendritic cell antigen presentation, but its role in T-cell immunity is unknown. Here we show that genetic deletion of Hrd1 in mice inhibits T-cell proliferation, production of IL-2, and differentiation of Th1 and Th17 cells, and consequently protects mice from experimental autoimmune encephalomyelitis. Hrd1 facilitates T-cell proliferation by the destruction of cyclin-dependent kinase inhibitor p27kip1, and deletion of p27kip1 in Hrd1-null T-cells rescues proliferative capacity but not the production of cytokines, including IL-2, IFN-γ and IL-17. T-cell expression of Hrd1 is higher in patients with multiple sclerosis than in healthy individuals, and knockdown of Hrd1 in human CD4+ T cells inhibits activation and differentiation to Th1 and Th17 cells. Our study identifies Hrd1 as a previously unappreciated positive regulator of T cells and implies that Hrd1 is a potential therapeutic target for autoimmune diseases. PMID:27417417

  19. Applying High-Speed Vision Sensing to an Industrial Robot for High-Performance Position Regulation under Uncertainties.

    PubMed

    Huang, Shouren; Bergström, Niklas; Yamakawa, Yuji; Senoo, Taku; Ishikawa, Masatoshi

    2016-01-01

    It is traditionally difficult to implement fast and accurate position regulation on an industrial robot in the presence of uncertainties. The uncertain factors can be attributed either to the industrial robot itself (e.g., a mismatch of dynamics, mechanical defects such as backlash, etc.) or to the external environment (e.g., calibration errors, misalignment or perturbations of a workpiece, etc.). This paper proposes a systematic approach to implement high-performance position regulation under uncertainties on a general industrial robot (referred to as the main robot) with minimal or no manual teaching. The method is based on a coarse-to-fine strategy that involves configuring an add-on module for the main robot's end effector. The add-on module consists of a 1000 Hz vision sensor and a high-speed actuator to compensate for accumulated uncertainties. The main robot only focuses on fast and coarse motion, with its trajectories automatically planned by image information from a static low-cost camera. Fast and accurate peg-and-hole alignment in one dimension was implemented as an application scenario by using a commercial parallel-link robot and an add-on compensation module with one degree of freedom (DoF). Experimental results yielded an almost 100% success rate for fast peg-in-hole manipulation (with regulation accuracy at about 0.1 mm) when the workpiece was randomly placed. PMID:27483274

  20. The ER membrane-anchored ubiquitin ligase Hrd1 is a positive regulator of T-cell immunity.

    PubMed

    Xu, Yuanming; Zhao, Fang; Qiu, Quan; Chen, Kun; Wei, Juncheng; Kong, Qingfei; Gao, Beixue; Melo-Cardenas, Johanna; Zhang, Bin; Zhang, Jinping; Song, Jianxun; Zhang, Donna D; Zhang, Jianing; Fan, Yunping; Li, Huabin; Fang, Deyu

    2016-01-01

    Identification of positive regulators of T-cell immunity induced during autoimmune diseases is critical for developing novel therapies. The endoplasmic reticulum resident ubiquitin ligase Hrd1 has recently emerged as a critical regulator of dendritic cell antigen presentation, but its role in T-cell immunity is unknown. Here we show that genetic deletion of Hrd1 in mice inhibits T-cell proliferation, production of IL-2, and differentiation of Th1 and Th17 cells, and consequently protects mice from experimental autoimmune encephalomyelitis. Hrd1 facilitates T-cell proliferation by the destruction of cyclin-dependent kinase inhibitor p27(kip1), and deletion of p27(kip1) in Hrd1-null T-cells rescues proliferative capacity but not the production of cytokines, including IL-2, IFN-γ and IL-17. T-cell expression of Hrd1 is higher in patients with multiple sclerosis than in healthy individuals, and knockdown of Hrd1 in human CD4(+) T cells inhibits activation and differentiation to Th1 and Th17 cells. Our study identifies Hrd1 as a previously unappreciated positive regulator of T cells and implies that Hrd1 is a potential therapeutic target for autoimmune diseases. PMID:27417417

  1. m:Explorer: multinomial regression models reveal positive and negative regulators of longevity in yeast quiescence

    PubMed Central

    2012-01-01

    We developed m:Explorer for identifying process-specific transcription factors (TFs) from multiple genome-wide sources, including transcriptome, DNA-binding and chromatin data. m:Explorer robustly outperforms similar techniques in finding cell cycle TFs in Saccharomyces cerevisiae. We predicted and experimentally tested regulators of quiescence (G0), a model of ageing, over a six-week time-course. We validated nine of top-12 predictions as novel G0 TFs, including Δmga2, Δcst6, Δbas1 with higher viability and G0-essential TFs Tup1, Swi3. Pathway analysis associates longevity to reduced growth, reprogrammed metabolism and cell wall remodeling. m:Explorer (http://biit.cs.ut.ee/mexplorer/) is instrumental in interrogating eukaryotic regulatory systems using heterogeneous data. PMID:22720667

  2. The kinases Mst1 and Mst2 positively regulate phagocyte ROS induction and bactericidal activity

    PubMed Central

    Geng, Jing; Sun, Xiufeng; Wang, Ping; Zhang, Shihao; Wang, Xiaozhen; Wu, Hongtan; Hong, Lixin; Xie, Changchuan; Li, Xun; Zhao, Hao; Liu, Qingxu; Jiang, Mingting; Chen, Qinghua; Zhang, Jinjia; Li, Yang; Song, Siyang; Wang, Hong-Rui; Zhou, Rongbin; Johnson, Randy L.; Chien, Kun-Yi; Lin, Sheng-Cai; Han, Jiahuai; Avruch, Joseph; Chen, Lanfen; Zhou, Dawang

    2015-01-01

    Summary Mitochondria need to be juxtaposted to phagosomes to synergistically produce ample reactive oxygen species (ROS) in phagocytes for pathogens killing. However, how phagosomes transmit signal to recruit mitochondria remains unclear. Here, we report that the kinases Mst1 and Mst2 function to control ROS production by regulating mitochondrial trafficking and mitochondrion-phagosome juxtaposition. Mst1 and Mst2 activate Rac GTPase to promote Toll-like receptor (TLR)-triggered assembly of the TRAF6-ECSIT complex that is required for mitochondrial recruitment to phagosomes. Inactive forms of Rac, including the human Rac2D57N mutant, disrupt the TRAF6-ECSIT complex by sequestering TRAF6, and severely dampen ROS production and greatly increase susceptibility to bacterial infection. These findings demonstrate the TLR-Mst1-Mst2-Rac signalling axis to be critical for effective phagosome-mitochondrion function and bactericidal activity. PMID:26414765

  3. Thymine DNA Glycosylase Is a Positive Regulator of Wnt Signaling in Colorectal Cancer*

    PubMed Central

    Xu, Xuehe; Yu, Tianxin; Shi, Jiandang; Chen, Xi; Zhang, Wen; Lin, Ting; Liu, Zhihong; Wang, Yadong; Zeng, Zheng; Wang, Chi; Li, Mingsong; Liu, Chunming

    2014-01-01

    Wnt signaling plays an important role in colorectal cancer (CRC). Although the mechanisms of β-catenin degradation have been well studied, the mechanism by which β-catenin activates transcription is still not fully understood. While screening a panel of DNA demethylases, we found that thymine DNA glycosylase (TDG) up-regulated Wnt signaling. TDG interacts with the transcription factor TCF4 and coactivator CREB-binding protein/p300 in the Wnt pathway. Knocking down TDG by shRNAs inhibited the proliferation of CRC cells in vitro and in vivo. In CRC patients, TDG levels were significantly higher in tumor tissues than in the adjacent normal tissues. These results suggest that TDG warrants consideration as a potential biomarker for CRC and as a target for CRC treatment. PMID:24532795

  4. SUMO-activating SAE1 transcription is positively regulated by Myc

    PubMed Central

    Amente, Stefano; Lavadera, Miriam Lubrano; Palo, Giacomo Di; Majello, Barbara

    2012-01-01

    Myc protein plays a fundamental role in regulation of cell cycle, proliferation, differentiation and apoptosis by modulating the expression of a large number of targets. Here we report the transactivation ability of the human Myc protein to activate the SUMO-activating enzyme SAE1 transcription. We found that Myc activates SAE1 transcription via direct binding to canonical E-Boxes sequences located close to the SAE1 transcription start site. A recent report has highlighted the crucial role of the SAE gene expression in Myc mediated oncogenesis. Our study adds new insight in this context since we show here that Myc directly activates SAE1 transcription, suggesting that Myc oncogenic activity which depends on SAE1 is ensured by Myc itself through direct binding and transcriptional activation of SAE1 expression. PMID:22679563

  5. DDA3 targets Cep290 into the centrosome to regulate spindle positioning.

    PubMed

    Song, Haiyu; Park, Ji Eun; Jang, Chang-Young

    The centrosome is an important cellular organelle which nucleates microtubules (MTs) to form the cytoskeleton during interphase and the mitotic spindle during mitosis. The Cep290 is one of the centrosomal proteins and functions in cilia formation. Even-though it is in the centrosome, the function of Cep290 in mitosis had not yet been evaluated. In this study, we report a novel function of Cep290 that is involved in spindle positioning. Cep290 was identified as an interacting partner of DDA3, and we confirmed that Cep290 specifically localizes in the mitotic centrosome. Depletion of Cep290 caused a reduction of the astral spindle, leading to misorientation of the mitotic spindle. MT polymerization also decreased in Cep290-depleted cells, suggesting that Cep290 is involved in spindle nucleation. Furthermore, DDA3 stabilizes and transports Cep290 to the centrosome. Therefore, we concluded that DDA3 controls astral spindle formation and spindle positioning by targeting Cep290 to the centrosome. PMID:25998387

  6. A mitotic SKAP isoform regulates spindle positioning at astral microtubule plus ends.

    PubMed

    Kern, David M; Nicholls, Peter K; Page, David C; Cheeseman, Iain M

    2016-05-01

    The Astrin/SKAP complex plays important roles in mitotic chromosome alignment and centrosome integrity, but previous work found conflicting results for SKAP function. Here, we demonstrate that SKAP is expressed as two distinct isoforms in mammals: a longer, testis-specific isoform that was used for the previous studies in mitotic cells and a novel, shorter mitotic isoform. Unlike the long isoform, short SKAP rescues SKAP depletion in mitosis and displays robust microtubule plus-end tracking, including localization to astral microtubules. Eliminating SKAP microtubule binding results in severe chromosome segregation defects. In contrast, SKAP mutants specifically defective for plus-end tracking facilitate proper chromosome segregation but display spindle positioning defects. Cells lacking SKAP plus-end tracking have reduced Clasp1 localization at microtubule plus ends and display increased lateral microtubule contacts with the cell cortex, which we propose results in unbalanced dynein-dependent cortical pulling forces. Our work reveals an unappreciated role for the Astrin/SKAP complex as an astral microtubule mediator of mitotic spindle positioning. PMID:27138257

  7. Regulation of Neuronal Morphogenesis and Positioning by Ubiquitin-Specific Proteases in the Cerebellum

    PubMed Central

    Anckar, Julius; Bonni, Azad

    2015-01-01

    Ubiquitin signaling mechanisms play fundamental roles in the cell-intrinsic control of neuronal morphogenesis and connectivity in the brain. However, whereas specific ubiquitin ligases have been implicated in key steps of neural circuit assembly, the roles of ubiquitin-specific proteases (USPs) in the establishment of neuronal connectivity have remained unexplored. Here, we report a comprehensive analysis of USP family members in granule neuron morphogenesis and positioning in the rodent cerebellum. We identify a set of 32 USPs that are expressed in granule neurons. We also characterize the subcellular localization of the 32 USPs in granule neurons using a library of expression plasmids encoding GFP-USPs. In RNAi screens of the 32 neuronally expressed USPs, we uncover novel functions for USP1, USP4, and USP20 in the morphogenesis of granule neuron dendrites and axons and we identify a requirement for USP30 and USP33 in granule neuron migration in the rodent cerebellar cortex in vivo. These studies reveal that specific USPs with distinct spatial localizations harbor key functions in the control of neuronal morphogenesis and positioning in the mammalian cerebellum, with important implications for our understanding of the cell-intrinsic mechanisms that govern neural circuit assembly in the brain. PMID:25607801

  8. Regulating knee joint position by combining electrical stimulation with a controllable friction brake.

    PubMed

    Durfee, W K; Hausdorff, J M

    1990-01-01

    Hybrid FES gait restoration systems which combine stimulation with controllable mechanical damping elements at the joints show promise for providing good control of limb motion despite variations in muscle properties. In this paper we compared three controllers for position tracking of the free swinging shank in able-bodied subjects. The controllers were open-loop (OL), proportional-derivative closed-loop (PD), and bang-bang plus controlled-brake control (CB). Both OL and PD controllers contained a forward path element, which inverted a model of the electrically stimulated muscle and limb system. The CB control was achieved by maximally activating the appropriate muscle group and controlling the brake to be a "moving-wall" against which the limb pushed. The CB control resulted in superior tracking performance for a wide range of position tracking tasks and muscle fatigue states but required no calibration or knowledge of muscle properties. The disadvantages of CB control include excess mechanical power dissipation in the brake and impact forces applied to the skeletal system. PMID:2281882

  9. Smoking, self-regulation and moral positioning: a focus group study with British smokers from a disadvantaged community.

    PubMed

    Gough, Brendan; Antoniak, Marilyn; Docherty, Graeme; Jones, Laura; Stead, Martine; McNeill, Ann

    2013-01-01

    Smoking in many Western societies has become a both moral aand health issue in recent years, but little is known about how smokers position themselves and regulate their behaviour in this context. In this article, we report the findings from a study investigating how smokers from an economically disadvantaged community in the East Midlands (UK) respond to concerns about the health impact of smoking on others. We conducted ten focus group (FG) discussions with mixed groups (by smoking status and gender; N = 58 participants) covering a range of topics, including smoking norms, self-regulation, and smoking in diverse contexts. We transcribed all FG discussions before analysing the data using techniques from discourse analysis. Smokers in general positioned themselves as socially responsible smokers and morally upstanding citizens. This position was bolstered in two main ways: 'everyday accommodation', whereby everyday efforts to accommodate the needs of non-smokers were referenced, and 'taking a stand', whereby proactive interventions to prevent smoking in (young) others were cited. We suggest that smoking cessation campaigns could usefully be informed by this ethic of care for others. PMID:23710702

  10. CaCDPK15 positively regulates pepper responses to Ralstonia solanacearum inoculation and forms a positive-feedback loop with CaWRKY40 to amplify defense signaling.

    PubMed

    Shen, Lei; Yang, Sheng; Yang, Tong; Liang, Jiaqi; Cheng, Wei; Wen, Jiayu; Liu, Yanyan; Li, Jiazhi; Shi, Lanping; Tang, Qian; Shi, Wei; Hu, Jiong; Liu, Cailing; Zhang, Yangwen; Mou, Shaoliang; Liu, Zhiqin; Cai, Hanyang; He, Li; Guan, Deyi; Wu, Yang; He, Shuilin

    2016-01-01

    CaWRKY40 is a positive regulator of pepper (Capsicum annum) response to Ralstonia solanacearum inoculation (RSI), but the underlying mechanism remains largely unknown. Here, we functionally characterize CaCDPK15 in the defense signaling mediated by CaWRKY40. Pathogen-responsive TGA, W, and ERE boxes were identified in the CaCDPK15 promoter (pCaCDPK15), and pCaCDPK15-driven GUS expression was significantly enhanced in response to RSI and exogenously applied salicylic acid, methyl jasmonate, abscisic acid, and ethephon. Virus-induced gene silencing (VIGS) of CaCDPK15 significantly increased the susceptibility of pepper to RSI and downregulated the immunity-associated markers CaNPR1, CaPR1, and CaDEF1. By contrast, transient CaCDPK15 overexpression significantly activated hypersensitive response associated cell death, upregulated the immunity-associated marker genes, upregulated CaWRKY40 expression, and enriched CaWRKY40 at the promoters of its targets genes. Although CaCDPK15 failed to interact with CaWRKY40, the direct binding of CaWRKY40 to pCaCDPK15 was detected by chromatin immunoprecipitation, which was significantly potentiated by RSI in pepper plants. These combined results suggest that RSI in pepper induces CaCDPK15 and indirectly activates downstream CaWRKY40, which in turn potentiates CaCDPK15 expression. This positive-feedback loop would amplify defense signaling against RSI and efficiently activate strong plant immunity. PMID:26928570

  11. CaCDPK15 positively regulates pepper responses to Ralstonia solanacearum inoculation and forms a positive-feedback loop with CaWRKY40 to amplify defense signaling

    PubMed Central

    Shen, Lei; Yang, Sheng; Yang, Tong; Liang, Jiaqi; Cheng, Wei; Wen, Jiayu; Liu, Yanyan; Li, Jiazhi; Shi, Lanping; Tang, Qian; Shi, Wei; Hu, Jiong; Liu, Cailing; Zhang, Yangwen; Mou, Shaoliang; Liu, Zhiqin; Cai, Hanyang; He, Li; Guan, Deyi; Wu, Yang; He, Shuilin

    2016-01-01

    CaWRKY40 is a positive regulator of pepper (Capsicum annum) response to Ralstonia solanacearum inoculation (RSI), but the underlying mechanism remains largely unknown. Here, we functionally characterize CaCDPK15 in the defense signaling mediated by CaWRKY40. Pathogen-responsive TGA, W, and ERE boxes were identified in the CaCDPK15 promoter (pCaCDPK15), and pCaCDPK15-driven GUS expression was significantly enhanced in response to RSI and exogenously applied salicylic acid, methyl jasmonate, abscisic acid, and ethephon. Virus-induced gene silencing (VIGS) of CaCDPK15 significantly increased the susceptibility of pepper to RSI and downregulated the immunity-associated markers CaNPR1, CaPR1, and CaDEF1. By contrast, transient CaCDPK15 overexpression significantly activated hypersensitive response associated cell death, upregulated the immunity-associated marker genes, upregulated CaWRKY40 expression, and enriched CaWRKY40 at the promoters of its targets genes. Although CaCDPK15 failed to interact with CaWRKY40, the direct binding of CaWRKY40 to pCaCDPK15 was detected by chromatin immunoprecipitation, which was significantly potentiated by RSI in pepper plants. These combined results suggest that RSI in pepper induces CaCDPK15 and indirectly activates downstream CaWRKY40, which in turn potentiates CaCDPK15 expression. This positive-feedback loop would amplify defense signaling against RSI and efficiently activate strong plant immunity. PMID:26928570

  12. The regulation of positive and negative social feedback: A psychophysiological study.

    PubMed

    Vanderhasselt, Marie-Anne; Remue, Jonathan; Ng, Kwun Kei; Mueller, Sven C; De Raedt, Rudi

    2015-09-01

    Everyday social evaluations are psychologically potent and trigger self-reflective thoughts and feelings. The present study sought to examine the psychophysiological impact of such evaluations using eye tracking, pupillometry, and heart-rate variability. Fifty-nine healthy adult volunteers received rigged social feedback (criticism and praise) based on their photograph. Gaze data were collected to investigate processes of attentional deployment/allocation toward the self or the evaluator expressing criticism or praise. Whereas voluntary attention was directed to evaluators who expressed praise, attention was drawn to one's own picture after criticism. Pupil dilation and heart-rate variability were larger in response to criticism as compared to praise, suggesting a flexible and adaptive emotion regulatory effort in response to social information that triggers an affective response. Altogether, healthy individuals recruited more regulatory resources to cope with negative (as compared to positive) social feedback, and this processing of social feedback was associated with adjustments in self-focused attention. PMID:25810280

  13. Chromosome position at the spindle equator is regulated by chromokinesin and a bipolar microtubule array.

    PubMed

    Takagi, Jun; Itabashi, Takeshi; Suzuki, Kazuya; Ishiwata, Shin'ichi

    2013-01-01

    The chromosome alignment is mediated by polar ejection and poleward forces acting on the chromosome arm and kinetochores, respectively. Although components of the motile machinery such as chromokinesin have been characterized, their dynamics within the spindle is poorly understood. Here we show that a quantum dot (Qdot) binding up to four Xenopus chromokinesin (Xkid) molecules behaved like a nanosize chromosome arm in the meiotic spindle, which is self-organized in cytoplasmic egg extracts. Xkid-Qdots travelled long distances along microtubules by changing several tracks, resulting in their accumulation toward and distribution around the metaphase plate. The analysis indicated that the direction of motion and velocity depend on the distribution of microtubule polarity within the spindle. Thus, this mechanism is governed by chromokinesin motors, which is dependent on symmetrical microtubule orientation that may allow chromosomes to maintain their position around the spindle equator until correct microtubule-kinetochore attachment is established. PMID:24077015

  14. Multilayered Regulation of Ethylene Induction Plays a Positive Role in Arabidopsis Resistance against Pseudomonas syringae.

    PubMed

    Guan, Rongxia; Su, Jianbin; Meng, Xiangzong; Li, Sen; Liu, Yidong; Xu, Juan; Zhang, Shuqun

    2015-09-01

    Ethylene, a key phytohormone involved in plant-pathogen interaction, plays a positive role in plant resistance against fungal pathogens. However, its function in plant bacterial resistance remains unclear. Here, we report a detailed analysis of ethylene induction in Arabidopsis (Arabidopsis thaliana) in response to Pseudomonas syringae pv tomato DC3000 (Pst). Ethylene biosynthesis is highly induced in both pathogen/microbe-associated molecular pattern (PAMP)-triggered immunity and effector-triggered immunity (ETI), and the induction is potentiated by salicylic acid (SA) pretreatment. In addition, Pst actively suppresses PAMP-triggered ethylene induction in a type III secretion system-dependent manner. SA potentiation of ethylene induction is dependent mostly on MITOGEN-ACTIVATED PROTEIN KINASE6 (MPK6) and MPK3 and their downstream ACS2 and ACS6, two type I isoforms of 1-aminocyclopropane-1-carboxylic acid synthases (ACSs). ACS7, a type III ACS whose expression is enhanced by SA pretreatment, is also involved. Pst expressing the avrRpt2 effector gene (Pst-avrRpt2), which is capable of triggering ETI, induces a higher level of ethylene production, and the elevated portion is dependent on SALICYLIC ACID INDUCTION DEFICIENT2 and NONEXPRESSER OF PATHOGENESIS-RELATED GENE1, two key players in SA biosynthesis and signaling. High-order ACS mutants with reduced ethylene induction are more susceptible to both Pst and Pst-avrRpt2, demonstrating a positive role of ethylene in plant bacterial resistance mediated by both PAMP-triggered immunity and ETI. PMID:26265775

  15. Vps33b regulates Vwf-positive vesicular trafficking in megakaryocytes.

    PubMed

    Dai, Jing; Lu, Yeling; Wang, Conghui; Chen, Xue; Fan, Xuemei; Gu, Hao; Wu, Xiaolin; Wang, Kemin; Gartner, T Kent; Zheng, Junke; Chen, Guoqiang; Wang, Xuefeng; Liu, Junling

    2016-09-01

    Mutations of vacuolar protein sorting-associated protein 33b (VPS33B) cause arthrogryposis, renal dysfunction, and cholestasis syndrome, and a lack of platelet α-granules in the affected patients. Conditional Vps33b knockout mice were developed to investigate the function(s) of Vps33b in platelet α-granule formation. We found that early embryonic deletion of Vps33b was lethal. PF4-Cre-driven megakaryocyte-targeted Vps33b gene deletion greatly diminished Vps33b expression in platelets, but had no effect on platelet α-granule formation and protein content. Tamoxifen-induced, haematopoietic stem cell (HSC)-specific Vps33b deletion completely depleted Vps33b in platelets, caused the absence of α-granules, and increased the number of vacuoles in platelets and megakaryocytes. VPS33B association with VIPAS39, α-tubulin, and SEC22B was identified by co-immunoprecipitation, mass spectra, and immunoblotting in human embryonic kidney 293T (HEK293T) cells. Also, pull-down experiments revealed that VIPAS39 bound to intact VPS33B; in contrast, α-tubulin and SEC22B separately interacted with the sec1-like domains of VPS33B. Vps33b deficiency in megakaryocytes disturbs the redistribution of Vipas39 and Sec22b to proplatelets, and interrupted the co-localization of Sec22b with Vwf-positive vesicles. The data presented in this study suggest that Vps33b is involved in α-granule formation possibly by facilitating the Vwf-positive vesicular trafficking to α-granule-related vacuoles in megakaryocytes. Copyright © 2016 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd. PMID:27319744

  16. PINK1 positively regulates HDAC3 to suppress dopaminergic neuronal cell death.

    PubMed

    Choi, Hyo-Kyoung; Choi, Youngsok; Kang, HeeBum; Lim, Eun-Jin; Park, Soo-Yeon; Lee, Hyun-Seob; Park, Ji-Min; Moon, Jisook; Kim, Yoon-Jung; Choi, Insup; Joe, Eun-Hye; Choi, Kyung-Chul; Yoon, Ho-Geun

    2015-02-15

    Deciphering the molecular basis of neuronal cell death is a central issue in the etiology of neurodegenerative diseases, such as Parkinson's and Alzheimer's. Dysregulation of p53 levels has been implicated in neuronal apoptosis. The role of histone deacetylase 3 (HDAC3) in suppressing p53-dependent apoptosis has been recently emphasized; however, the molecular basis of modulation of p53 function by HDAC3 remains unclear. Here we show that PTEN-induced putative kinase 1 (PINK1), which is linked to autosomal recessive early-onset familial Parkinson's disease, phosphorylates HDAC3 at Ser-424 to enhance its HDAC activity in a neural cell-specific manner. PINK1 prevents H2O2-induced C-terminal cleavage of HDAC3 via phosphorylation of HDAC3 at Ser-424, which is reversed by protein phosphatase 4c. PINK1-mediated phosphorylation of HDAC3 enhances its direct association with p53 and causes subsequent hypoacetylation of p53. Genetic deletion of PINK1 partly impaired the suppressive role of HDAC3 in regulating p53 acetylation and transcriptional activity. However, depletion of HDAC3 fully abolished the PINK1-mediated p53 inhibitory loop. Finally, ectopic expression of phosphomometic-HDAC3(S424E) substantially overcomes the defective action of PINK1 against oxidative stress in dopaminergic neuronal cells. Together, our results uncovered a mechanism by which PINK1-HDAC3 network mediates p53 inhibitory loop in response to oxidative stress-induced damage. PMID:25305081

  17. Positive Regulation of Neocortical Synapse Formation by the Plexin-D1 Receptor

    PubMed Central

    Levitt, P.

    2015-01-01

    Synapse formation is a critical process during neural development and is coordinated by multiple signals. Several lines of evidence implicate the Plexin-D1 receptor in synaptogenesis. Studies have shown that Plexin-D1 signaling is involved in synaptic specificity and synapse formation in spinal cord and striatum. Expression of Plexin-D1 and its principal neural ligand, Sema3E, by neocortical neurons is temporally and spatially regulated, reaching the highest level at the time of synaptogenesis in mice. In this study, we examined the function of Plexin-D1 in synapse formation by primary neocortical neurons in vitro. A novel, automated image analysis method was developed to quantitate synapse formation under baseline conditions and with manipulation of Plexin-D1 levels. shRNA and overexpression manipulations caused opposite changes, with reduction resulting in less synapse formation, an effect distinct from that reported in the striatum. The data indicate that Plexin-D1 operates in a cell context-specific fashion, mediating different synaptogenic outcomes depending upon neuron type. PMID:25976775

  18. The transcription factor CREBZF is a novel positive regulator of p53

    PubMed Central

    López-Mateo, Irene; Villaronga, M. Ángeles; Llanos, Susana; Belandia, Borja

    2012-01-01

    CREBZF is a member of the mammalian ATF/CREB family of transcription factors. Here, we describe a novel functional interaction between CREBZF and the tumor suppressor p53. CREBZF was identified in a yeast two-hybrid screen using HEY1, recently characterized as an indirect p53 activator, as bait. CREBZF interacts in vitro with both HEY1 and p53, and CREBZF expression stabilizes and activates p53. Moreover, CREBZF cooperates synergistically with HEY1 to enhance p53 transcriptional activity. On the other hand, partial depletion of endogenous CREBZF diminishes p53 protein levels and inhibits HEY1-mediated activation of p53. CREBZF-positive effects on p53 signaling may reflect, at least in part, an observed induction of posttranslational modifications in p53 known to prevent its degradation. CREBZF expression protects HCT116 cells from UV radiation-induced cell death. In addition, CREBZF expression confers sensitivity to 5-fluorouracil, a p53-activating chemotherapeutic drug. Our study suggests that CREBZF may participate in the modulation of p53 tumor suppressor function. PMID:22983008

  19. ATG7 regulates energy metabolism, differentiation and survival of Philadelphia-chromosome-positive cells

    PubMed Central

    Karvela, Maria; Baquero, Pablo; Kuntz, Elodie M.; Mukhopadhyay, Arunima; Mitchell, Rebecca; Allan, Elaine K.; Chan, Edmond; Kranc, Kamil R.; Calabretta, Bruno; Salomoni, Paolo; Gottlieb, Eyal; Holyoake, Tessa L.; Helgason, G. Vignir

    2016-01-01

    ABSTRACT A major drawback of tyrosine kinase inhibitor (TKI) treatment in chronic myeloid leukemia (CML) is that primitive CML cells are able to survive TKI-mediated BCR-ABL inhibition, leading to disease persistence in patients. Investigation of strategies aiming to inhibit alternative survival pathways in CML is therefore critical. We have previously shown that a nonspecific pharmacological inhibition of autophagy potentiates TKI-induced death in Philadelphia chromosome-positive cells. Here we provide further understanding of how specific and pharmacological autophagy inhibition affects nonmitochondrial and mitochondrial energy metabolism and reactive oxygen species (ROS)-mediated differentiation of CML cells and highlight ATG7 (a critical component of the LC3 conjugation system) as a potential specific therapeutic target. By combining extra- and intracellular steady state metabolite measurements by liquid chromatography-mass spectrometry with metabolic flux assays using labeled glucose and functional assays, we demonstrate that knockdown of ATG7 results in decreased glycolysis and increased flux of labeled carbons through the mitochondrial tricarboxylic acid cycle. This leads to increased oxidative phosphorylation and mitochondrial ROS accumulation. Furthermore, following ROS accumulation, CML cells, including primary CML CD34+ progenitor cells, differentiate toward the erythroid lineage. Finally, ATG7 knockdown sensitizes CML progenitor cells to TKI-induced death, without affecting survival of normal cells, suggesting that specific inhibitors of ATG7 in combination with TKI would provide a novel therapeutic approach for CML patients exhibiting persistent disease. PMID:27168493

  20. ATG7 regulates energy metabolism, differentiation and survival of Philadelphia-chromosome-positive cells.

    PubMed

    Karvela, Maria; Baquero, Pablo; Kuntz, Elodie M; Mukhopadhyay, Arunima; Mitchell, Rebecca; Allan, Elaine K; Chan, Edmond; Kranc, Kamil R; Calabretta, Bruno; Salomoni, Paolo; Gottlieb, Eyal; Holyoake, Tessa L; Helgason, G Vignir

    2016-06-01

    A major drawback of tyrosine kinase inhibitor (TKI) treatment in chronic myeloid leukemia (CML) is that primitive CML cells are able to survive TKI-mediated BCR-ABL inhibition, leading to disease persistence in patients. Investigation of strategies aiming to inhibit alternative survival pathways in CML is therefore critical. We have previously shown that a nonspecific pharmacological inhibition of autophagy potentiates TKI-induced death in Philadelphia chromosome-positive cells. Here we provide further understanding of how specific and pharmacological autophagy inhibition affects nonmitochondrial and mitochondrial energy metabolism and reactive oxygen species (ROS)-mediated differentiation of CML cells and highlight ATG7 (a critical component of the LC3 conjugation system) as a potential specific therapeutic target. By combining extra- and intracellular steady state metabolite measurements by liquid chromatography-mass spectrometry with metabolic flux assays using labeled glucose and functional assays, we demonstrate that knockdown of ATG7 results in decreased glycolysis and increased flux of labeled carbons through the mitochondrial tricarboxylic acid cycle. This leads to increased oxidative phosphorylation and mitochondrial ROS accumulation. Furthermore, following ROS accumulation, CML cells, including primary CML CD34(+) progenitor cells, differentiate toward the erythroid lineage. Finally, ATG7 knockdown sensitizes CML progenitor cells to TKI-induced death, without affecting survival of normal cells, suggesting that specific inhibitors of ATG7 in combination with TKI would provide a novel therapeutic approach for CML patients exhibiting persistent disease. PMID:27168493

  1. FK506 binding protein 51 positively regulates melanoma stemness and metastatic potential.

    PubMed

    Romano, S; Staibano, S; Greco, A; Brunetti, A; Nappo, G; Ilardi, G; Martinelli, R; Sorrentino, A; Di Pace, A; Mascolo, M; Bisogni, R; Scalvenzi, M; Alfano, B; Romano, M F

    2013-01-01

    Melanoma is the most aggressive skin cancer; there is no cure in advanced stages. Identifying molecular participants in melanoma progression may provide useful diagnostic and therapeutic tools. FK506 binding protein 51 (FKBP51), an immunophilin with a relevant role in developmental stages, is highly expressed in melanoma and correlates with aggressiveness and therapy resistance. We hypothesized a role for FKBP51 in melanoma invasive behaviour. FKBP51 promoted activation of epithelial-to-mesenchymal transition (EMT) genes and improved melanoma cell migration and invasion. In addition, FKBP51 induced some melanoma stem cell (MCSC) genes. Purified MCSCs expressed high EMT genes levels, suggesting that genetic programs of EMT and MCSCs overlap. Immunohistochemistry of samples from patients showed intense FKBP51 nuclear signal and cytoplasmic positivity for the stem cell marker nestin in extravasating melanoma cells and metastatic brains. In addition, FKBP51 targeting by small interfering RNA (siRNA) prevented the massive metastatic substitution of liver and lung in a mouse model of experimental metastasis. The present study provides evidence that the genetic programs of cancer stemness and invasiveness overlap in melanoma, and that FKBP51 plays a pivotal role in sustaining such a program. PMID:23559012

  2. FK506 binding protein 51 positively regulates melanoma stemness and metastatic potential

    PubMed Central

    Romano, S; Staibano, S; Greco, A; Brunetti, A; Nappo, G; Ilardi, G; Martinelli, R; Sorrentino, A; Di Pace, A; Mascolo, M; Bisogni, R; Scalvenzi, M; Alfano, B; Romano, M F

    2013-01-01

    Melanoma is the most aggressive skin cancer; there is no cure in advanced stages. Identifying molecular participants in melanoma progression may provide useful diagnostic and therapeutic tools. FK506 binding protein 51 (FKBP51), an immunophilin with a relevant role in developmental stages, is highly expressed in melanoma and correlates with aggressiveness and therapy resistance. We hypothesized a role for FKBP51 in melanoma invasive behaviour. FKBP51 promoted activation of epithelial-to-mesenchymal transition (EMT) genes and improved melanoma cell migration and invasion. In addition, FKBP51 induced some melanoma stem cell (MCSC) genes. Purified MCSCs expressed high EMT genes levels, suggesting that genetic programs of EMT and MCSCs overlap. Immunohistochemistry of samples from patients showed intense FKBP51 nuclear signal and cytoplasmic positivity for the stem cell marker nestin in extravasating melanoma cells and metastatic brains. In addition, FKBP51 targeting by small interfering RNA (siRNA) prevented the massive metastatic substitution of liver and lung in a mouse model of experimental metastasis. The present study provides evidence that the genetic programs of cancer stemness and invasiveness overlap in melanoma, and that FKBP51 plays a pivotal role in sustaining such a program. PMID:23559012

  3. Protection of Armadillo/β-Catenin by Armless, a Novel Positive Regulator of Wingless Signaling

    PubMed Central

    Reim, Gerlinde; Hruzova, Martina; Goetze, Sandra; Basler, Konrad

    2014-01-01

    The Wingless (Wg/Wnt) signaling pathway is essential for metazoan development, where it is central to tissue growth and cellular differentiation. Deregulated Wg pathway activation underlies severe developmental abnormalities, as well as carcinogenesis. Armadillo/β-Catenin plays a key role in the Wg transduction cascade; its cytoplasmic and nuclear levels directly determine the output activity of Wg signaling and are thus tightly controlled. In all current models, once Arm is targeted for degradation by the Arm/β-Catenin destruction complex, its fate is viewed as set. We identified a novel Wg/Wnt pathway component, Armless (Als), which is required for Wg target gene expression in a cell-autonomous manner. We found by genetic and biochemical analyses that Als functions downstream of the destruction complex, at the level of the SCF/Slimb/βTRCP E3 Ub ligase. In the absence of Als, Arm levels are severely reduced. We show by biochemical and in vivo studies that Als interacts directly with Ter94, an AAA ATPase known to associate with E3 ligases and to drive protein turnover. We suggest that Als antagonizes Ter94's positive effect on E3 ligase function and propose that Als promotes Wg signaling by rescuing Arm from proteolytic degradation, spotlighting an unexpected step where the Wg pathway signal is modulated. PMID:25369031

  4. The transcription factor CREBZF is a novel positive regulator of p53.

    PubMed

    López-Mateo, Irene; Villaronga, M Ángeles; Llanos, Susana; Belandia, Borja

    2012-10-15

    CREBZF is a member of the mammalian ATF/CREB family of transcription factors. Here, we describe a novel functional interaction between CREBZF and the tumor suppressor p53. CREBZF was identified in a yeast two-hybrid screen using HEY1, recently characterized as an indirect p53 activator, as bait. CREBZF interacts in vitro with both HEY1 and p53, and CREBZF expression stabilizes and activates p53. Moreover, CREBZF cooperates synergistically with HEY1 to enhance p53 transcriptional activity. On the other hand, partial depletion of endogenous CREBZF diminishes p53 protein levels and inhibits HEY1-mediated activation of p53. CREBZF-positive effects on p53 signaling may reflect, at least in part, an observed induction of posttranslational modifications in p53 known to prevent its degradation. CREBZF expression protects HCT116 cells from UV radiation-induced cell death. In addition, CREBZF expression confers sensitivity to 5-fluorouracil, a p53-activating chemotherapeutic drug. Our study suggests that CREBZF may participate in the modulation of p53 tumor suppressor function. PMID:22983008

  5. Positive regulation of osteoclastic differentiation by growth differentiation factor 15 upregulated in osteocytic cells under hypoxia.

    PubMed

    Hinoi, Eiichi; Ochi, Hiroki; Takarada, Takeshi; Nakatani, Eri; Iezaki, Takashi; Nakajima, Hiroko; Fujita, Hiroyuki; Takahata, Yoshifumi; Hidano, Shinya; Kobayashi, Takashi; Takeda, Shu; Yoneda, Yukio

    2012-04-01

    Osteocytes are thought to play a role as a mechanical sensor through their communication network in bone. Although osteocytes are the most abundant cells in bone, little attention has been paid to their physiological and pathological functions in skeletogenesis. Here, we have attempted to delineate the pivotal functional role of osteocytes in regulation of bone remodeling under pathological conditions. We first found markedly increased osteoclastic differentiation by conditioned media (CM) from osteocytic MLO-Y4 cells previously exposed to hypoxia in vitro. Using microarray and real-time PCR analyses, we identified growth differentiation factor 15 (GDF15) as a key candidate factor secreted from osteocytes under hypoxia. Recombinant GDF15 significantly promoted osteoclastic differentiation in a concentration-dependent manner, with concomitant facilitation of phosphorylation of both p65 and inhibitory-κB in the presence of receptor activator of nuclear factor-κB ligand. To examine the possible functional significance of GDF15 in vivo, mice were subjected to ligation of the right femoral artery as a hypoxic model. A significant increase in GDF15 expression was specifically observed in tibias of the ligated limb but not in tibias of the normally perfused limb. Under these experimental conditions, in cancellous bone of proximal tibias in the ligated limb, a significant reduction was observed in bone volume, whereas a significant increase was seen in the extent of osteoclast surface/bone surface when determined by bone histomorphometric analysis. Finally, the anti-GDF15 antibody prevented bone loss through inhibiting osteoclastic activation in tibias from mice with femoral artery ligation in vivo, in addition to suppressing osteoclastic activity enhanced by CM from osteocytes exposed to hypoxia in vitro. These findings suggest that GDF15 could play a pivotal role in the pathogenesis of bone loss relevant to hypoxia through promotion of osteoclastogenesis after

  6. Proteasome Modulates Positive and Negative Translational Regulators in Long-Term Synaptic Plasticity

    PubMed Central

    Dong, Chenghai; Bach, Svitlana V.; Haynes, Kathryn A.

    2014-01-01

    Proteolysis by the ubiquitin-proteasome pathway appears to have a complex role in synaptic plasticity, but its various functions remain to be elucidated. Using late phase long-term potentiation (L-LTP) in the hippocampus of the mouse as a model for long-term synaptic plasticity, we previously showed that inhibition of the proteasome enhances induction but blocks maintenance of L-LTP. In this study, we investigated the possible mechanisms by which proteasome inhibition has opposite effects on L-LTP induction and maintenance. Our results show that inhibiting phosphatidyl inositol-3 kinase or blocking the interaction between eukaryotic initiation factors 4E (eIF4E) and 4G (eIF4G) reduces the enhancement of L-LTP induction brought about by proteasome inhibition suggesting interplay between proteolysis and the signaling pathway mediated by mammalian target of rapamycin (mTOR). Also, proteasome inhibition leads to accumulation of translational activators in the mTOR pathway such as eIF4E and eukaryotic elongation factor 1A (eEF1A) early during L-LTP causing increased induction. Furthermore, inhibition of the proteasome causes a buildup of translational repressors, such as polyadenylate-binding protein interacting protein 2 (Paip2) and eukaryotic initiation factor 4E-binding protein 2 (4E-BP2), during late stages of L-LTP contributing to the blockade of L-LTP maintenance. Thus, the proteasome plays a critical role in regulating protein synthesis during L-LTP by tightly controlling translation. Our results provide novel mechanistic insights into the interplay between protein degradation and protein synthesis in long-term synaptic plasticity. PMID:24573276

  7. Lysosome-associated membrane proteins (LAMPs) regulate intracellular positioning of mitochondria in MC3T3-E1 cells.

    PubMed

    Rajapakshe, Anupama R; Podyma-Inoue, Katarzyna A; Terasawa, Kazue; Hasegawa, Katsuya; Namba, Toshimitsu; Kumei, Yasuhiro; Yanagishita, Masaki; Hara-Yokoyama, Miki

    2015-02-01

    The intracellular positioning of both lysosomes and mitochondria meets the requirements of degradation and energy supply, which are respectively the two major functions for cellular maintenance. The positioning of both lysosomes and mitochondria is apparently affected by the nutrient status of the cells. However, the mechanism coordinating the positioning of the organelles has not been sufficiently elucidated. Lysosome-associated membrane proteins-1 and -2 (LAMP-1 and LAMP-2) are highly glycosylated proteins that are abundant in lysosomal membranes. In the present study, we demonstrated that the siRNA-mediated downregulation of LAMP-1, LAMP-2 or their combination enhanced the perinuclear localization of mitochondria, in the pre-osteoblastic cell line MC3T3-E1. On the other hand, in the osteocytic cell line MLO-Y4, in which both the lysosomes and mitochondria originally accumulate in the perinuclear region and mitochondria also fill dendrites, the effect of siRNA of LAMP-1 or LAMP-2 was barely observed. LAMPs are not directly associated with mitochondria, and there do not seem to be any accessory molecules commonly required to recruit the motor proteins to lysosomes and mitochondria. Our results suggest that LAMPs may regulate the positioning of lysosomes and mitochondria. A possible mechanism involving the indirect and context-dependent action of LAMPs is discussed. PMID:25246127

  8. Defining a role for Hfq in Gram-positive bacteria: evidence for Hfq-dependent antisense regulation in Listeria monocytogenes

    PubMed Central

    Nielsen, Jesper Sejrup; Lei, Lisbeth Kristensen; Ebersbach, Tine; Olsen, Anders Steno; Klitgaard, Janne Kudsk; Valentin-Hansen, Poul; Kallipolitis, Birgitte Haahr

    2010-01-01

    Small trans-encoded RNAs (sRNAs) modulate the translation and decay of mRNAs in bacteria. In Gram-negative species, antisense regulation by trans-encoded sRNAs relies on the Sm-like protein Hfq. In contrast to this, Hfq is dispensable for sRNA-mediated riboregulation in the Gram-positive species studied thus far. Here, we provide evidence for Hfq-dependent translational repression in the Gram-positive human pathogen Listeria monocytogenes, which is known to encode at least 50 sRNAs. We show that the Hfq-binding sRNA LhrA controls the translation and degradation of its target mRNA by an antisense mechanism, and that Hfq facilitates the binding of LhrA to its target. The work presented here provides the first experimental evidence for Hfq-dependent riboregulation in a Gram-positive bacterium. Our findings indicate that modulation of translation by trans-encoded sRNAs may occur by both Hfq-dependent and -independent mechanisms, thus adding another layer of complexity to sRNA-mediated riboregulation in Gram-positive species. PMID:19942685

  9. Tbx Protein Level Critical for Clock-Mediated Somite Positioning Is Regulated through Interaction between Tbx and Ripply

    PubMed Central

    Wanglar, Chimwar; Takahashi, Jun; Yabe, Taijiro; Takada, Shinji

    2014-01-01

    Somitogenesis in vertebrates is a complex and dynamic process involving many sequences of events generated from the segmentation clock. Previous studies with mouse embryos revealed that the presumptive somite boundary is periodically created at the anterior border of the expression domain of Tbx6 protein. Ripply1 and Ripply2 are required for the determination of the Tbx6 protein border, but the mechanism by which this Tbx6 domain is regulated remains unclear. Furthermore, since zebrafish and frog Ripplys are known to be able to suppress Tbx6 function at the transcription level, it is also unclear whether Ripply-mediated mechanism of Tbx6 regulation is conserved among different species. Here, we tested the generality of Tbx6 protein-mediated process in somite segmentation by using zebrafish and further examined the mechanism of regulation of Tbx6 protein. By utilizing an antibody against zebrafish Tbx6/Fss, previously referred to as Tbx24, we found that the anterior border of Tbx6 domain coincided with the presumptive intersomitic boundary even in the zebrafish and it shifted dynamically during 1 cycle of segmentation. Consistent with the findings in mice, the tbx6 mRNA domain was located far anterior to its protein domain, indicating the possibility of posttranscriptional regulation. When both ripply1/2 were knockdown, the Tbx6 domain was anteriorly expanded. We further directly demonstrated that Ripply could reduce the expression level of Tbx6 protein depending on physical interaction between Ripply and Tbx6. Moreover, the onset of ripply1 and ripply2 expression occurred after reduction of FGF signaling at the anterior PSM, but this expression initiated much earlier on treatment with SU5402, a chemical inhibitor of FGF signaling. These results strongly suggest that Ripply is a direct regulator of the Tbx6 protein level for the establishment of intersomitic boundaries and mediates a reduction in FGF signaling for the positioning of the presumptive intersomitic

  10. Positive Role of Promyelocytic Leukemia Protein in Type I Interferon Response and Its Regulation by Human Cytomegalovirus

    PubMed Central

    Kim, Young-Eui; Ahn, Jin-Hyun

    2015-01-01

    Promyelocytic leukemia protein (PML), a major component of PML nuclear bodies (also known as nuclear domain 10), is involved in diverse cellular processes such as cell proliferation, apoptosis, gene regulation, and DNA damage response. PML also acts as a restriction factor that suppresses incoming viral genomes, therefore playing an important role in intrinsic defense. Here, we show that PML positively regulates type I interferon response by promoting transcription of interferon-stimulated genes (ISGs) and that this regulation by PML is counteracted by human cytomegalovirus (HCMV) IE1 protein. Small hairpin RNA-mediated PML knockdown in human fibroblasts reduced ISG induction by treatment of interferon-β or infection with UV-inactivated HCMV. PML was required for accumulation of activated STAT1 and STAT2, interacted with them and HDAC1 and HDAC2, and was associated with ISG promoters after HCMV infection. During HCMV infection, viral IE1 protein interacted with PML, STAT1, STAT2, and HDACs. Analysis of IE1 mutant viruses revealed that, in addition to the STAT2-binding domain, the PML-binding domain of IE1 was necessary for suppression of interferon-β-mediated ISG transcription, and that IE1 inhibited ISG transcription by sequestering interferon-stimulated gene factor 3 (ISGF3) in a manner requiring its binding of PML and STAT2, but not of HDACs. In conclusion, our results demonstrate that PML participates in type I interferon-induced ISG expression by regulating ISGF3, and that this regulation by PML is counteracted by HCMV IE1, highlighting a widely shared viral strategy targeting PML to evade intrinsic and innate defense mechanisms. PMID:25812002

  11. Sox2 Regulates Cholinergic Amacrine Cell Positioning and Dendritic Stratification in the Retina

    PubMed Central

    Whitney, Irene E.; Keeley, Patrick W.; St. John, Ace J.; Kautzman, Amanda G.; Kay, Jeremy N.

    2014-01-01

    The retina contains two populations of cholinergic amacrine cells, one positioned in the ganglion cell layer (GCL) and the other in the inner nuclear layer (INL), that together comprise ∼1/2 of a percent of all retinal neurons. The present study examined the genetic control of cholinergic amacrine cell number and distribution between these two layers. The total number of cholinergic amacrine cells was quantified in the C57BL/6J and A/J inbred mouse strains, and in 25 recombinant inbred strains derived from them, and variations in their number and ratio (GCL/INL) across these strains were mapped to genomic loci. The total cholinergic amacrine cell number was found to vary across the strains, from 27,000 to 40,000 cells, despite little variation within individual strains. The number of cells was always lower within the GCL relative to the INL, and the sizes of the two populations were strongly correlated, yet there was variation in their ratio between the strains. Approximately 1/3 of that variation in cell ratio was mapped to a locus on chromosome 3, where Sex determining region Y box 2 (Sox2) was identified as a candidate gene due to the presence of a 6-nucleotide insertion in the protein-coding sequence in C57BL/6J and because of robust and selective expression in cholinergic amacrine cells. Conditionally deleting Sox2 from the population of nascent cholinergic amacrine cells perturbed the normal ratio of cells situated in the GCL versus the INL and induced a bistratifying morphology, with dendrites distributed to both ON and OFF strata within the inner plexiform layer. PMID:25057212

  12. A super-family of transcriptional activators regulates bacteriophage packaging and lysis in Gram-positive bacteria.

    PubMed

    Quiles-Puchalt, Nuria; Tormo-Más, María Ángeles; Campoy, Susana; Toledo-Arana, Alejandro; Monedero, Vicente; Lasa, Iñigo; Novick, Richard P; Christie, Gail E; Penadés, José R

    2013-08-01

    The propagation of bacteriophages and other mobile genetic elements requires exploitation of the phage mechanisms involved in virion assembly and DNA packaging. Here, we identified and characterized four different families of phage-encoded proteins that function as activators required for transcription of the late operons (morphogenetic and lysis genes) in a large group of phages infecting Gram-positive bacteria. These regulators constitute a super-family of proteins, here named late transcriptional regulators (Ltr), which share common structural, biochemical and functional characteristics and are unique to this group of phages. They are all small basic proteins, encoded by genes present at the end of the early gene cluster in their respective phage genomes and expressed under cI repressor control. To control expression of the late operon, the Ltr proteins bind to a DNA repeat region situated upstream of the terS gene, activating its transcription. This involves the C-terminal part of the Ltr proteins, which control specificity for the DNA repeat region. Finally, we show that the Ltr proteins are the only phage-encoded proteins required for the activation of the packaging and lysis modules. In summary, we provide evidence that phage packaging and lysis is a conserved mechanism in Siphoviridae infecting a wide variety of Gram-positive bacteria. PMID:23771138

  13. Positive regulation of minichromosome maintenance gene expression, DNA replication, and cell transformation by a plant retinoblastoma gene

    PubMed Central

    Sabelli, Paolo A.; Hoerster, George; Lizarraga, Lucina E.; Brown, Sara W.; Gordon-Kamm, William J.; Larkins, Brian A.

    2009-01-01

    Retinoblastoma-related (RBR) genes inhibit the cell cycle primarily by repressing adenovirus E2 promoter binding factor (E2F) transcription factors, which drive the expression of numerous genes required for DNA synthesis and cell cycle progression. The RBR-E2F pathway is conserved in plants, but cereals such as maize are characterized by having a complex RBR gene family with at least 2 functionally distinct members, RBR1 and RBR3. Although RBR1 has a clear cell cycle inhibitory function, it is not known whether RBR3 has a positive or negative role. By uncoupling RBR3 from the negative regulation of RBR1 in cultured maize embryos through a combination of approaches, we demonstrate that RBR3 has a positive and critical role in the expression of E2F targets required for the initiation of DNA synthesis, DNA replication, and the efficiency with which transformed plants can be obtained. Titration of endogenous RBR3 activity through expression of a dominant-negative allele with a compromised pocket domain suggests that these RBR3 functions require an activity distinct from its pocket domain. Our results indicate a cell cycle pathway in maize, in which 2 RBR genes have specific and opposing functions. Thus, the paradigm that RBR genes are negative cell cycle regulators cannot be considered universal. PMID:19234120

  14. A super-family of transcriptional activators regulates bacteriophage packaging and lysis in Gram-positive bacteria

    PubMed Central

    Quiles-Puchalt, Nuria; Tormo-Más, María Ángeles; Campoy, Susana; Toledo-Arana, Alejandro; Monedero, Vicente; Lasa, Íñigo; Novick, Richard P.; Christie, Gail E.; Penadés, José R.

    2013-01-01

    The propagation of bacteriophages and other mobile genetic elements requires exploitation of the phage mechanisms involved in virion assembly and DNA packaging. Here, we identified and characterized four different families of phage-encoded proteins that function as activators required for transcription of the late operons (morphogenetic and lysis genes) in a large group of phages infecting Gram-positive bacteria. These regulators constitute a super-family of proteins, here named late transcriptional regulators (Ltr), which share common structural, biochemical and functional characteristics and are unique to this group of phages. They are all small basic proteins, encoded by genes present at the end of the early gene cluster in their respective phage genomes and expressed under cI repressor control. To control expression of the late operon, the Ltr proteins bind to a DNA repeat region situated upstream of the terS gene, activating its transcription. This involves the C-terminal part of the Ltr proteins, which control specificity for the DNA repeat region. Finally, we show that the Ltr proteins are the only phage-encoded proteins required for the activation of the packaging and lysis modules. In summary, we provide evidence that phage packaging and lysis is a conserved mechanism in Siphoviridae infecting a wide variety of Gram-positive bacteria. PMID:23771138

  15. Polar Positioning of Phase-Separated Liquid Compartments in Cells Regulated by an mRNA Competition Mechanism.

    PubMed

    Saha, Shambaditya; Weber, Christoph A; Nousch, Marco; Adame-Arana, Omar; Hoege, Carsten; Hein, Marco Y; Osborne-Nishimura, Erin; Mahamid, Julia; Jahnel, Marcus; Jawerth, Louise; Pozniakovski, Andrej; Eckmann, Christian R; Jülicher, Frank; Hyman, Anthony A

    2016-09-01

    P granules are non-membrane-bound RNA-protein compartments that are involved in germline development in C. elegans. They are liquids that condense at one end of the embryo by localized phase separation, driven by gradients of polarity proteins such as the mRNA-binding protein MEX-5. To probe how polarity proteins regulate phase separation, we combined biochemistry and theoretical modeling. We reconstitute P granule-like droplets in vitro using a single protein PGL-3. By combining in vitro reconstitution with measurements of intracellular concentrations, we show that competition between PGL-3 and MEX-5 for mRNA can regulate the formation of PGL-3 droplets. Using theory, we show that, in a MEX-5 gradient, this mRNA competition mechanism can drive a gradient of P granule assembly with similar spatial and temporal characteristics to P granule assembly in vivo. We conclude that gradients of polarity proteins can position RNP granules during development by using RNA competition to regulate local phase separation. PMID:27594427

  16. CytR Is a Global Positive Regulator of Competence, Type VI Secretion, and Chitinases in Vibrio cholerae

    PubMed Central

    Hammer, Brian K.

    2015-01-01

    The facultative pathogen Vibrio cholerae transitions between its human host and aquatic reservoirs where it colonizes chitinous surfaces. Growth on chitin induces expression of chitin utilization genes, genes involved in DNA uptake by natural transformation, and a type VI secretion system that allows contact-dependent killing of neighboring bacteria. We have previously shown that the transcription factor CytR, thought to primarily regulate the pyrimidine nucleoside scavenging response, is required for natural competence in V. cholerae. Through high-throughput RNA sequencing (RNA-seq), we show that CytR positively regulates the majority of competence genes, the three type VI secretion operons, and the four known or predicted chitinases. We used transcriptional reporters and phenotypic analysis to determine the individual contributions of quorum sensing, which is controlled by the transcription factors HapR and QstR; chitin utilization that is mediated by TfoX; and pyrimidine starvation that is orchestrated by CytR, toward each of these processes. We find that in V. cholerae, CytR is a global regulator of multiple behaviors affecting fitness and adaptability in the environment. PMID:26401962

  17. Los1p, Involved in Yeast Pre-Trna Splicing, Positively Regulates Members of the Sol Gene Family

    PubMed Central

    Shen, W. C.; Stanford, D. R.; Hopper, A. K.

    1996-01-01

    To understand the role of Los1p in pre-tRNA splicing, we sought los1 multicopy suppressors. We found SOL1 that suppresses both point and null LOS1 mutations. Since, when fused to the Gal4p DNA-binding domain, Los1p activates transcription, we tested whether Los1p regulates SOL1. We found that los1 mutants have depleted levels of SOL1 mRNA and Sollp. Thus, LOS1 appears to positively regulate SOL1. SOL1 belongs to a multigene family with at least two additional members, SOL2 and SOL3. Sol proteins have extensive similarity to an unusual group of glucose-6-phosphate dehydrogenases. As the similarities are restricted to areas separate from the catalytic domain, these G6PDs may have more than one function. The SOL family appears to be unessential since cells with a triple disruption of all three SOL genes are viable. SOL gene disruptions negatively affect tRNA-mediated nonsense suppression and the severity increases with the number of mutant SOL genes. However, tRNA levels do not vary with either multicopy SOL genes or with SOL disruptions. Therefore, the Sol proteins affect tRNA expression/function at steps other than transcription or splicing. We propose that LOS1 regulates gene products involved in tRNA expression/function as well as pre-tRNA splicing. PMID:8725220

  18. Los1p, involved in yeast pre-tRNA splicing, positively regulates members of the SOL gene family

    SciTech Connect

    Shen, W.C.; Stanford, D.R.; Hopper, A.K.

    1996-06-01

    To understand the role of Los1p in pre-tRNA splicing, we sought los1 multicopy suppressors. We found SOL1 that suppresses both point and null LOS1 mutations. Since, when fused to the Gal4p DNA-binding domain, Los1p activates transcription, we tested whether Los1p regulates SOL1. We found that los1 mutants have depleted levels of SOL1 mRNA and Sol1p. Thus, LOS1 appears to positively regulate SOL1. SOL1 belongs to a multigene family with at least two additional members, SOL2 and SOL3. Sol proteins have extensive similarity to an unusual group of glucose-6-phosphate dehydrogenases (G6PDs). As the similarities are restricted to areas separate from the catalytic domain, these G6PDs may have more than one function. The SOL gene disruptions negatively affect tRNA-mediated nonsense suppression and the severity increases with the number of mutant SOL genes. However, tRNA levels do not vary with either multicopy SOL genes or with SOL disruptions. Therefore, the Sol proteins affect tRNA expression/function at steps other than transcription or splicing. We propose that LOS1 regulates gene products involved in tRNA expression/function as well as pre-tRNA splicing. 64 refs., 6 figs., 6 tabs.

  19. Arabidopsis DE-ETIOLATED1 Represses Photomorphogenesis by Positively Regulating Phytochrome-Interacting Factors in the Dark[C][W

    PubMed Central

    Dong, Jie; Tang, Dafang; Gao, Zhaoxu; Yu, Renbo; Li, Kunlun; He, Hang; Terzaghi, William; Deng, Xing Wang

    2014-01-01

    Arabidopsis thaliana seedlings undergo photomorphogenic development even in darkness when the function of DE-ETIOLATED1 (DET1), a repressor of photomorphogenesis, is disrupted. However, the mechanism by which DET1 represses photomorphogenesis remains unclear. Our results indicate that DET1 directly interacts with a group of transcription factors known as the phytochrome-interacting factors (PIFs). Furthermore, our results suggest that DET1 positively regulates PIF protein levels primarily by stabilizing PIF proteins in the dark. Genetic analysis showed that each pif single mutant could enhance the det1-1 phenotype, and ectopic expression of each PIF in det1-1 partially suppressed the det1-1 phenotype, based on hypocotyl elongation and cotyledon opening angles observed in darkness. Genomic analysis also revealed that DET1 may modulate the expression of light-regulated genes to mediate photomorphogenesis partially through PIFs. The observed interaction and regulation between DET1 and PIFs not only reveal how DET1 represses photomorphogenesis, but also suggest a possible mechanism by which two groups of photomorphogenic repressors, CONSTITUTIVE PHOTOMORPHOGENESIS/DET/FUSCA and PIFs, work in concert to repress photomorphogenesis in darkness. PMID:25248553

  20. Zinc-Finger Transcription Factor ZAT6 Positively Regulates Cadmium Tolerance through the Glutathione-Dependent Pathway in Arabidopsis.

    PubMed

    Chen, Jian; Yang, Libo; Yan, Xingxing; Liu, Yunlei; Wang, Ren; Fan, Tingting; Ren, Yongbing; Tang, Xiaofeng; Xiao, Fangming; Liu, Yongsheng; Cao, Shuqing

    2016-05-01

    Cadmium (Cd) is an environmental pollutant with high toxicity to animals and plants. It has been established that the glutathione (GSH)-dependent phytochelatin (PC) synthesis pathway is one of the most important mechanisms contributing to Cd accumulation and tolerance in plants. However, the transcription factors involved in regulating GSH-dependent PC synthesis pathway remain largely unknown. Here, we identified an Arabidopsis (Arabidopsis thaliana) Cd-resistant mutant xcd2-D (XVE system-induced cadmium-tolerance2) using a forward genetics approach. The mutant gene underlying xcd2-D mutation was revealed to encode a known zinc-finger transcription factor, ZAT6. Transgenic plants overexpressing ZAT6 showed significant increase of Cd tolerance, whereas loss of function of ZAT6 led to decreased Cd tolerance. Increased Cd accumulation and tolerance in ZAT6-overexpressing lines was GSH dependent and associated with Cd-activated synthesis of PC, which was correlated with coordinated activation of PC-synthesis related gene expression. By contrast, loss of function of ZAT6 reduced Cd accumulation and tolerance, which was accompanied by abolished PC synthesis and gene expression. Further analysis revealed that ZAT6 positively regulates the transcription of GSH1, GSH2, PCS1, and PCS2, but ZAT6 is capable of specifically binding to GSH1 promoter in vivo. Consistently, overexpression of GSH1 has been shown to restore Cd sensitivity in the zat6-1 mutant, suggesting that GSH1 is a key target of ZAT6. Taken together, our data provide evidence that ZAT6 coordinately activates PC synthesis-related gene expression and directly targets GSH1 to positively regulate Cd accumulation and tolerance in Arabidopsis. PMID:26983992

  1. Positive feedback regulation between adiponectin and T-cadherin impacts adiponectin levels in tissue and plasma of male mice.

    PubMed

    Matsuda, Keisuke; Fujishima, Yuya; Maeda, Norikazu; Mori, Takuya; Hirata, Ayumu; Sekimoto, Ryohei; Tsushima, Yu; Masuda, Shigeki; Yamaoka, Masaya; Inoue, Kana; Nishizawa, Hitoshi; Kita, Shunbun; Ranscht, Barbara; Funahashi, Tohru; Shimomura, Iichiro

    2015-03-01

    Adiponectin (Adipo), a multimeric adipocyte-secreted protein abundant in the circulation, is implicated in cardiovascular protective functions. Recent work documented that Adipo locally associates with responsive tissues through interactions with T-cadherin (Tcad), an atypical, glycosylphosphatidylinositol (GPI)-anchored cadherin cell surface glycoprotein. Mice deficient for Tcad lack tissue-associated Adipo, accumulate Adipo in the circulation, and mimic the Adipo knockout (KO) cardiovascular phenotype. In reverse, Tcad protein is visibly reduced from cardiac tissue in Adipo-KO mice, suggesting interdependent regulation of the 2 proteins. Here, we evaluate the effect of Adipo on Tcad protein expression. Adipo and Tcad proteins were colocalized in aorta, heart, and skeletal muscle. Adipo positively regulated levels of Tcad protein in vivo and in endothelial cell (EC) cultures. In Tcad-KO mice, binding of endogenous and exogenously administered Adipo to cardiovascular tissues was dramatically reduced. Consistently, knockdown of Tcad in cultured murine vascular ECs significantly diminished Adipo binding. In search for a possible mechanism, we found that enzymatic cleavage of Tcad with phosphatidylinositol-specific phospholipase C increases plasma Adipo while decreasing tissue-bound levels. Similarly, pretreatment of cultured ECs with serum containing Adipo attenuated phosphatidylinositol-specific phospholipase C-mediated Tcad cleavage. In vivo administration of adenovirus producing Adipo suppressed plasma levels of GPI phospholipase D, the endogenous cleavage enzyme for GPI-anchored proteins. In conclusion, our data show that both circulating and tissue-bound Adipo levels are dependent on Tcad and, in reverse, regulate tissue Tcad levels through a positive feedback loop that operates by suppressing phospholipase-mediated Tcad release from the cell surface. PMID:25514086

  2. Transcriptional regulation of E-cadherin and oncoprotein E7 by valproic acid in HPV positive cell lines

    PubMed Central

    Faghihloo, Ebrahim; Akbari, Abolfazl; Adjaminezhad-Fard, Fatemeh; Mokhtari-Azad, Talat

    2016-01-01

    Objective(s): Valproic acid (VPA) has proven to be as one of the most promising useful drug with anticancer properties. In this study, we investigate the VPA effects on E-cadherin expression in HeLa, TC1, MKN45, and HCT116 cell lines. This study assesses the effects of VPA on human papillomavirus E7 expression in HPV positive cell lines. Materials and Methods: Cell lines were treated by 2 mmol/l VPA and expression of E-cadherin and E7 was analyzed by quantitative real-time PCR. Student’s t test and ANOVA were used to determine changes in expression levels. Results: The results revealed that mean of E-cadherin expression is increased by VPA 1.8 times in HCT116 and MKN45 cell lines, also the mean of E-cadherin mRNA levels is up-regulated 2.9 times in HeLa and TC1 cell lines. So, E-cadherin augmentation induced by VPA in HeLa and TC-1, HPV positive cell lines, is higher than HPV negative cell lines MKN45 and HCT116. The mean of HPV E7 expression is decreased by VPA, 4.6 times in in HeLa and TC-1 cell lines. Conclusion: This study demonstrates that re-expression of E-cadherin by VPA in HPV positive cell lines is more than HPV negative cell lines. Whereas, HPV E7 reduces the expression of E-cadherin, reduction of HPV E7 expression by VPA is related to more augmentation of E-cadherin in HPV positive cell lines. So, this study demonstrates that VPA has more anticancer properties in HPV positive cell lines, and could potentially be a promising candidate for cervical cancer treatment. PMID:27482340

  3. Regulation of Nuclear Positioning and Dynamics of the Silent Mating Type Loci by the Yeast Ku70/Ku80 Complex▿

    PubMed Central

    Bystricky, Kerstin; Van Attikum, Haico; Montiel, Maria-Dolores; Dion, Vincent; Gehlen, Lutz; Gasser, Susan M.

    2009-01-01

    We have examined the hypothesis that the highly selective recombination of an active mating type locus (MAT) with either HMLα or HMRa is facilitated by the spatial positioning of relevant sequences within the budding yeast (Saccharomyces cerevisiae) nucleus. However, both position relative to the nuclear envelope (NE) and the subnuclear mobility of fluorescently tagged MAT, HML, or HMR loci are largely identical in haploid a and α cells. Irrespective of mating type, the expressed MAT locus is highly mobile within the nuclear lumen, while silent loci move less and are found preferentially near the NE. The perinuclear positions of HMR and HML are strongly compromised in strains lacking the Silent information regulator, Sir4. However, HMLα, unlike HMRa and most telomeres, shows increased NE association in a strain lacking yeast Ku70 (yKu70). Intriguingly, we find that the yKu complex is associated with HML and HMR sequences in a mating-type-specific manner. Its abundance decreases at the HMLα donor locus and increases transiently at MATa following DSB induction. Our data suggest that mating-type-specific binding of yKu to HMLα creates a local chromatin structure competent for recombination, which cooperates with the recombination enhancer to direct donor choice for gene conversion of the MATa locus. PMID:19047366

  4. Autocrine Positive Feedback Regulation of Prolactin Release From Tilapia Prolactin Cells and Its Modulation by Extracellular Osmolality.

    PubMed

    Yamaguchi, Yoko; Moriyama, Shunsuke; Lerner, Darren T; Grau, E Gordon; Seale, Andre P

    2016-09-01

    Prolactin (PRL) is a vertebrate hormone with diverse actions in osmoregulation, metabolism, reproduction, and in growth and development. Osmoregulation is fundamental to maintaining the functional structure of the macromolecules that conduct the business of life. In teleost fish, PRL plays a critical role in osmoregulation in fresh water. Appropriately, PRL cells of the tilapia are directly osmosensitive, with PRL secretion increasing as extracellular osmolality falls. Using a model system that employs dispersed PRL cells from the euryhaline teleost fish, Oreochromis mossambicus, we investigated the autocrine regulation of PRL cell function. Unknown was whether these PRL cells might also be sensitive to autocrine feedback and whether possible autocrine regulation might interact with the well-established regulation by physiologically relevant changes in extracellular osmolality. In the cell-perfusion system, ovine PRL and two isoforms of tilapia PRL (tPRL), tPRL177 and tPRL188, stimulated the release of tPRLs from the dispersed PRL cells. These effects were significant within 5-10 minutes and lasted the entire course of exposure, ceasing within 5-10 minutes of removal of tested PRLs from the perifusion medium. The magnitude of response varied between tPRL177 and tPRL188 and was modulated by extracellular osmolality. On the other hand, the gene expression of tPRLs was mainly unchanged or suppressed by static incubations of PRL cells with added PRLs. By demonstrating the regulatory complexity driven by positive autocrine feedback and its interaction with osmotic stimuli, these findings expand upon the knowledge that pituitary PRL cells are regulated complexly through multiple factors and interactions. PMID:27379370

  5. Iron-Regulated Protein HupB of Mycobacterium tuberculosis Positively Regulates Siderophore Biosynthesis and Is Essential for Growth in Macrophages

    PubMed Central

    Pandey, Satya Deo; Choudhury, Mitali; Yousuf, Suhail; Wheeler, Paul R.; Gordon, Stephen V.; Ranjan, Akash

    2014-01-01

    Mycobacterium tuberculosis expresses the 28-kDa protein HupB (Rv2986c) and the Fe3+-specific high-affinity siderophores mycobactin and carboxymycobactin upon iron limitation. The objective of this study was to understand the functional role of HupB in iron acquisition. A hupB mutant strain of M. tuberculosis, subjected to growth in low-iron medium (0.02 μg Fe ml−1), showed a marked reduction of both siderophores with low transcript levels of the mbt genes encoding the MB biosynthetic machinery. Complementation of the mutant strain with hupB restored siderophore production to levels comparable to that of the wild type. We demonstrated the binding of HupB to the mbtB promoter by both electrophoretic mobility shift assays and DNA footprinting. The latter revealed the HupB binding site to be a 10-bp AT-rich region. While negative regulation of the mbt machinery by IdeR is known, this is the first report of positive regulation of the mbt operon by HupB. Interestingly, the mutant strain failed to survive inside macrophages, suggesting that HupB plays an important role in vivo. PMID:24610707

  6. The plasma membrane protein Rch1 is a negative regulator of cytosolic calcium homeostasis and positively regulated by the calcium/calcineurin signaling pathway in budding yeast.

    PubMed

    Zhao, Yunying; Yan, Hongbo; Happeck, Ricardo; Peiter-Volk, Tina; Xu, Huihui; Zhang, Yan; Peiter, Edgar; van Oostende Triplet, Chloë; Whiteway, Malcolm; Jiang, Linghuo

    2016-01-01

    Saccharomyces cerevisiae Rch1 is structurally similar to both the vertebrate solute carrier SLC10A7 and Candida albicans Rch1. We show here that ScRCH1 is a functional homolog of CaRCH1. In S. cerevisiae, overexpression of ScRCH1 suppresses, but deletion of ScRCH1 does not affect, the lithium and rapamycin tolerance of pmr1 cells. Overexpression of ScRCH1 reduces expression of ENA1, prevents sustained accumulation of cytosolic calcium and reduces the activation level of calcium/calcineurin signaling in pmr1 cells. Therefore, similar to the situation in the pathogen C. albicans, ScRch1 negatively regulates the cytosolic homeostasis in response to high levels of extracellular calcium. ScRch1 proteins distribute as multiple foci in the plasma membrane prior to cell division, move toward and concentrate at the bud neck as the bud grows in size, and disperse again along the plasma membrane immediately prior to cytokinesis. Furthermore, our genetic and biochemical data also demonstrate that transcriptional expression of RCH1 is positively regulated by calcium/calcineurin signaling through the sole CDRE element in its promoter. PMID:26832117

  7. Position-dependent activity of CELF2 in the regulation of splicing and implications for signal-responsive regulation in T cells

    PubMed Central

    Ajith, Sandya; Gazzara, Matthew R.; Cole, Brian S.; Shankarling, Ganesh; Martinez, Nicole M.; Mallory, Michael J.; Lynch, Kristen W.

    2016-01-01

    ABSTRACT CELF2 is an RNA binding protein that has been implicated in developmental and signal-dependent splicing in the heart, brain and T cells. In the heart, CELF2 expression decreases during development, while in T cells CELF2 expression increases both during development and in response to antigen-induced signaling events. Although hundreds of CELF2-responsive splicing events have been identified in both heart and T cells, the way in which CELF2 functions has not been broadly investigated. Here we use CLIP-Seq to identified physical targets of CELF2 in a cultured human T cell line. By comparing the results with known functional targets of CELF2 splicing regulation from the same cell line we demonstrate a generalizable position-dependence of CELF2 activity that is consistent with previous mechanistic studies of individual CELF2 target genes in heart and brain. Strikingly, this general position-dependence is sufficient to explain the bi-directional activity of CELF2 on 2 T cell targets recently reported. Therefore, we propose that the location of CELF2 binding around an exon is a primary predictor of CELF2 function in a broad range of cellular contexts. PMID:27096301

  8. Positive Charges at the Intracellular Mouth of the Pore Regulate Anion Conduction in the CFTR Chloride Channel

    PubMed Central

    Aubin, Chantal N. St.; Linsdell, Paul

    2006-01-01

    Many different ion channel pores are thought to have charged amino acid residues clustered around their entrances. The so-called surface charges contributed by these residues can play important roles in attracting oppositely charged ions from the bulk solution on one side of the membrane, increasing effective local counterion concentration and favoring rapid ion movement through the channel. Here we use site-directed mutagenesis to identify arginine residues contributing important surface charges in the intracellular mouth of the cystic fibrosis transmembrane conductance regulator (CFTR) Cl− channel pore. While wild-type CFTR was associated with a linear current–voltage relationship with symmetrical solutions, strong outward rectification was observed after mutagenesis of two arginine residues (R303 and R352) located near the intracellular ends of the fifth and sixth transmembrane regions. Current rectification was dependent on the charge present at these positions, consistent with an electrostatic effect. Furthermore, mutagenesis-induced rectification was more pronounced at lower Cl− concentrations, suggesting that these mutants had a reduced ability to concentrate Cl− ions near the inner pore mouth. R303 and R352 mutants exhibited reduced single channel conductance, especially at negative membrane potentials, that was dependent on the charge of the amino acid residue present at these positions. However, the very low conductance of both R303E and R352E-CFTR could be greatly increased by elevating intracellular Cl− concentration. Modification of an introduced cysteine residue at position 303 by charged methanethiosulfonate reagents reproduced charge-dependent effects on current rectification. Mutagenesis of arginine residues in the second and tenth transmembrane regions also altered channel permeation properties, however these effects were not consistent with changes in channel surface charges. These results suggest that positively charged arginine

  9. Positive charges at the intracellular mouth of the pore regulate anion conduction in the CFTR chloride channel.

    PubMed

    Aubin, Chantal N St; Linsdell, Paul

    2006-11-01

    Many different ion channel pores are thought to have charged amino acid residues clustered around their entrances. The so-called surface charges contributed by these residues can play important roles in attracting oppositely charged ions from the bulk solution on one side of the membrane, increasing effective local counterion concentration and favoring rapid ion movement through the channel. Here we use site-directed mutagenesis to identify arginine residues contributing important surface charges in the intracellular mouth of the cystic fibrosis transmembrane conductance regulator (CFTR) Cl(-) channel pore. While wild-type CFTR was associated with a linear current-voltage relationship with symmetrical solutions, strong outward rectification was observed after mutagenesis of two arginine residues (R303 and R352) located near the intracellular ends of the fifth and sixth transmembrane regions. Current rectification was dependent on the charge present at these positions, consistent with an electrostatic effect. Furthermore, mutagenesis-induced rectification was more pronounced at lower Cl(-) concentrations, suggesting that these mutants had a reduced ability to concentrate Cl(-) ions near the inner pore mouth. R303 and R352 mutants exhibited reduced single channel conductance, especially at negative membrane potentials, that was dependent on the charge of the amino acid residue present at these positions. However, the very low conductance of both R303E and R352E-CFTR could be greatly increased by elevating intracellular Cl(-) concentration. Modification of an introduced cysteine residue at position 303 by charged methanethiosulfonate reagents reproduced charge-dependent effects on current rectification. Mutagenesis of arginine residues in the second and tenth transmembrane regions also altered channel permeation properties, however these effects were not consistent with changes in channel surface charges. These results suggest that positively charged arginine residues

  10. Differential Expression of Claudin Family Members during Osteoblast and Osteoclast Differentiation: Cldn-1 Is a Novel Positive Regulator of Osteoblastogenesis

    PubMed Central

    Alshbool, Fatima Z.; Mohan, Subburaman

    2014-01-01

    involves cell type and differentiation stage-dependent regulation. In addition, Cldn-1 is a positive regulator of osteoblast proliferation and differentiation. PMID:25479235

  11. Characterization of a novel positive transcription regulatory element that differentially regulates the alpha-2-macroglobulin gene in replicative senescence.

    PubMed

    Li, Renzhong; Ma, Liwei; Huang, Yu; Zhang, Zongyu; Tong, Tanjun

    2011-12-01

    Alpha-2-macroglobulin (α2M), a protease inhibitor, is implicated in Alzheimer's disease, atherosclerosis, and other age-related diseases. The elevated level of α2M mRNA has been described in replicative senescence and it could be used as a biomarker of the aging cells. However, the mechanism responsible for the up-regulation of its expression is still unclear. This report identified a novel transcriptional regulatory element, the α2M transcription enhancement element (ATEE), within the α2M promoter. This element differentially activates α2M expression in senescent versus young fibroblasts. Electrophoretic mobility shift assays revealed abundant complexes in senescent cell nuclear extracts compared with young cell nuclear extracts. The DNase I footprint revealed the protein-binding core sequence through which the protein binds the ATEE. Mutation within ATEE selectively abolished α2M promoter activity in senescent (but not young) cells. These results indicated the ATEE, as a positive transcription regulatory element, contributes to the up-regulation of α2M during replicative senescence. PMID:21541797

  12. The Cotton WRKY Gene GhWRKY41 Positively Regulates Salt and Drought Stress Tolerance in Transgenic Nicotiana benthamiana

    PubMed Central

    Chen, Xiaobo; Lu, Wenjing; Li, Han; Wang, Xiuling; Hao, Lili; Guo, Xingqi

    2015-01-01

    WRKY transcription factors constitute a very large family of proteins in plants and participate in modulating plant biological processes, such as growth, development and stress responses. However, the exact roles of WRKY proteins are unclear, particularly in non-model plants. In this study, Gossypium hirsutum WRKY41 (GhWRKY41) was isolated and transformed into Nicotiana benthamiana. Our results showed that overexpression of GhWRKY41 enhanced the drought and salt stress tolerance of transgenic Nicotiana benthamiana. The transgenic plants exhibited lower malondialdehyde content and higher antioxidant enzyme activity, and the expression of antioxidant genes was upregulated in transgenic plants exposed to osmotic stress. A β-glucuronidase (GUS) staining assay showed that GhWRKY41 was highly expressed in the stomata when plants were exposed to osmotic stress, and plants overexpressing GhWRKY41 exhibited enhanced stomatal closure when they were exposed to osmotic stress. Taken together, our findings demonstrate that GhWRKY41 may enhance plant tolerance to stress by functioning as a positive regulator of stoma closure and by regulating reactive oxygen species (ROS) scavenging and the expression of antioxidant genes. PMID:26562293

  13. Characterisation of SalRAB a Salicylic Acid Inducible Positively Regulated Efflux System of Rhizobium leguminosarum bv viciae 3841

    PubMed Central

    Tett, Adrian J.; Karunakaran, Ramakrishnan; Poole, Philip S.

    2014-01-01

    Salicylic acid is an important signalling molecule in plant-microbe defence and symbiosis. We analysed the transcriptional responses of the nitrogen fixing plant symbiont, Rhizobium leguminosarum bv viciae 3841 to salicylic acid. Two MFS-type multicomponent efflux systems were induced in response to salicylic acid, rmrAB and the hitherto undescribed system salRAB. Based on sequence similarity salA and salB encode a membrane fusion and inner membrane protein respectively. salAB are positively regulated by the LysR regulator SalR. Disruption of salA significantly increased the sensitivity of the mutant to salicylic acid, while disruption of rmrA did not. A salA/rmrA double mutation did not have increased sensitivity relative to the salA mutant. Pea plants nodulated by salA or rmrA strains did not have altered nodule number or nitrogen fixation rates, consistent with weak expression of salA in the rhizosphere and in nodule bacteria. However, BLAST analysis revealed seventeen putative efflux systems in Rlv3841 and several of these were highly differentially expressed during rhizosphere colonisation, host infection and bacteroid differentiation. This suggests they have an integral role in symbiosis with host plants. PMID:25133394

  14. CUE1: A Mesophyll Cell-Specific Positive Regulator of Light-Controlled Gene Expression in Arabidopsis.

    PubMed Central

    Li, Hm.; Culligan, K.; Dixon, R. A.; Chory, J.

    1995-01-01

    Light plays a key role in the development and physiology of plants. One of the most profound effects of light on plant development is the derepression of expression of an array of light-responsive genes, including the genes encoding the chlorophyll a/b binding proteins (CAB) of photosystem II. To understand the mechanism by which light signals nuclear gene expression, we developed a genetic selection to identify mutants with reduced CAB transcription. Here, we describe a new Arabidopsis locus, CUE1 (for CAB underexpressed). Mutations at this locus result in defects in expression of several light-regulated genes, specifically in mesophyll but not in bundle-associated or epidermis cells. Reduced accumulation of CAB and other photosynthesis-related mRNAs in the mesophyll was correlated with defects in chloroplast development in these cells, resulting in a reticulate pattern with veins greener than the interveinal regions of leaves. Moreover, chalcone synthase mRNA, although known to be regulated by both phytochrome and a blue light receptor, accumulated normally in the leaf epidermis. Dark basal levels of CAB expression were unaffected in etiolated cue1 seedlings; however, induction of CAB transcription by pulses of red and blue light was reduced, suggesting that CUE1 acts downstream from both phytochrome and blue light photoreceptors. CUE1 appears to play a role in the primary derepression of mesophyll-specific gene expression in response to light, because cue1 mutants are severely deficient at establishing photoautotrophic growth. Based on this characterization, we propose that CUE1 is a cell-specific positive regulator linking light and intrinsic developmental programs in Arabidopsis leaf mesophyll cells. PMID:12242356

  15. Positive feedback regulation of type I IFN production by the IFN-inducible DNA sensor cGAS

    PubMed Central

    Ma, Feng; Li, Bing; Liu, Su-yang; Iyer, Shankar S; Yu, Yongxin; Wu, Aiping; Cheng, Genhong

    2014-01-01

    Rapid and robust induction of type I interferon (IFN-I) is a critical event in host antiviral innate immune response. It has been well demonstrated that cyclic GMP-AMP (cGAMP) synthase (cGAS) plays an important role in sensing cytosolic DNA and triggering stimulator of interferon genes (STING)-dependent signaling to induce IFN-I. However, it is largely unknown how cGAS itself is regulated during pathogen infection and IFN-I production. Here, we show that pattern-recognition receptor (PRR) ligands including lipidA, LPS, polyI:C, polydA:dT, and cGAMP induce cGAS expression in a IFN-I-dependent manner in both mouse and human macrophages. Further experiments indicate that cGAS is an IFN-stimulated gene (ISG), and two adjacent IFN-sensitive response elements (ISREs) in the promoter region of cGAS mediate the induction of cGAS by IFN-I. In addition, we show that optimal production of IFNβ triggered by polydA:dT or HSV-1 requires IFNAR signaling. Knockdown of the constitutively expressed DNA sensor DDX41 attenuates polydA:dT-triggered IFNβ production and cGAS induction. By analyzing the dynamic expression of polydA:dT-induced IFNβ and cGAS transcripts, we have found that induction of IFNβ is earlier than cGAS. Furthermore, we have provided evidence that induction of cGAS by IFN-I meditates the subsequent positive feedback regulation of DNA-triggered IFN-I production. Thus, our study not only provides a novel mechanism of modulating cGAS expression, but also adds another layer of regulation in DNA-triggered IFN-I production by induction of cGAS. PMID:25609843

  16. Arabidopsis AtERF15 positively regulates immunity against Pseudomonas syringae pv. tomato DC3000 and Botrytis cinerea

    PubMed Central

    Zhang, Huijuan; Huang, Lei; Dai, Yi; Liu, Shixia; Hong, Yongbo; Tian, Limei; Huang, Lihong; Cao, Zhongye; Li, Dayong; Song, Fengming

    2015-01-01

    Upon pathogen infection, activation of immune response requires effective transcriptional reprogramming that regulates inducible expression of a large set of defense genes. A number of ethylene-responsive factor transcription factors have been shown to play critical roles in regulating immune responses in plants. In the present study, we explored the functions of Arabidopsis AtERF15 in immune responses against Pseudomonas syringae pv. tomato (Pst) DC3000, a (hemi)biotrophic bacterial pathogen, and Botrytis cinerea, a necrotrophic fungal pathogen. Expression of AtERF15 was induced by infection of Pst DC3000 and B. cinerea and by treatments with salicylic acid (SA) and methyl jasmonate. Biochemical assays demonstrated that AtERF15 is a nucleus-localized transcription activator. The AtERF15-overexpressing (AtERF15-OE) plants displayed enhanced resistance while the AtERF15-RNAi plants exhibited decreased resistance against Pst DC3000 and B. cinerea. Meanwhile, Pst DC3000- or B. cinerea-induced expression of defense genes was upregulated in AtERF15-OE plants but downregulated in AtERF15-RNAi plants, as compared to the expression in wild type plants. In response to infection with B. cinerea, the AtERF15-OE plants accumulated less reactive oxygen species (ROS) while the AtERF15-RNAi plants accumulated more ROS. The flg22- and chitin-induced oxidative burst was abolished and expression levels of the pattern-triggered immunity-responsive genes AtFRK1 and AtWRKY53 were suppressed in AtER15-RNAi plants upon treatment with flg22 or chitin. Furthermore, SA-induced defense response was also partially impaired in the AtERF15-RNAi plants. These data demonstrate that AtERF15 is a positive regulator of multiple layers of the immune responses in Arabidopsis. PMID:26388886

  17. Sphingosine Kinase Regulates Microtubule Dynamics and Organelle Positioning Necessary for Proper G1/S Cell Cycle Transition in Trypanosoma brucei

    PubMed Central

    Pasternack, Deborah A.; Sharma, Aabha I.; Olson, Cheryl L.

    2015-01-01

    ABSTRACT Sphingolipids are important constituents of cell membranes and also serve as mediators of cell signaling and cell recognition. Sphingolipid metabolites such as sphingosine-1-phosphate and ceramide regulate signaling cascades involved in cell proliferation and differentiation, autophagy, inflammation, and apoptosis. Little is known about how sphingolipids and their metabolites function in single-celled eukaryotes. In the present study, we investigated the role of sphingosine kinase (SPHK) in the biology of the protozoan parasite Trypanosoma brucei, the agent of African sleeping sickness. T. brucei SPHK (TbSPHK) is constitutively but differentially expressed during the life cycle of T. brucei. Depletion of TbSPHK in procyclic-form T. brucei causes impaired growth and attenuation in the G1/S phase of the cell cycle. TbSPHK-depleted cells also develop organelle positioning defects and an accumulation of tyrosinated α-tubulin at the elongated posterior end of the cell, known as the “nozzle” phenotype, caused by other molecular perturbations in this organism. Our studies indicate that TbSPHK is involved in G1-to-S cell cycle progression, organelle positioning, and maintenance of cell morphology. Cytotoxicity assays using TbSPHK inhibitors revealed a favorable therapeutic index between T. brucei and human cells, suggesting TbSPHK to be a novel drug target. PMID:26443455

  18. Noncompetitive Counteractions of DNA Polymerase ɛ and ISW2/yCHRAC for Epigenetic Inheritance of Telomere Position Effect in Saccharomyces cerevisiae

    PubMed Central

    Iida, Tetsushi; Araki, Hiroyuki

    2004-01-01

    Relocation of euchromatic genes near the heterochromatin region often results in mosaic gene silencing. In Saccharomyces cerevisiae, cells with the genes inserted at telomeric heterochromatin-like regions show a phenotypic variegation known as the telomere-position effect, and the epigenetic states are stably passed on to following generations. Here we show that the epigenetic states of the telomere gene are not stably inherited in cells either bearing a mutation in a catalytic subunit (Pol2) of replicative DNA polymerase ɛ (Pol ɛ) or lacking one of the nonessential and histone fold motif-containing subunits of Pol ɛ, Dpb3 and Dpb4. We also report a novel and putative chromatin-remodeling complex, ISW2/yCHRAC, that contains Isw2, Itc1, Dpb3-like subunit (Dls1), and Dpb4. Using the single-cell method developed in this study, we demonstrate that without Pol ɛ and ISW2/yCHRAC, the epigenetic states of the telomere are frequently switched. Furthermore, we reveal that Pol ɛ and ISW2/yCHRAC function independently: Pol ɛ operates for the stable inheritance of a silent state, while ISW2/yCHRAC works for that of an expressed state. We therefore propose that inheritance of specific epigenetic states of a telomere requires at least two counteracting regulators. PMID:14673157

  19. Regulation of conductance by the number of fixed positive charges in the intracellular vestibule of the CFTR chloride channel pore

    PubMed Central

    Zhou, Jing-Jun; Li, Man-Song; Qi, Jiansong

    2010-01-01

    Rapid chloride permeation through the cystic fibrosis transmembrane conductance regulator (CFTR) Cl− channel is dependent on the presence of fixed positive charges in the permeation pathway. Here, we use site-directed mutagenesis and patch clamp recording to show that the functional role played by one such positive charge (K95) in the inner vestibule of the pore can be “transplanted” to a residue in a different transmembrane (TM) region (S1141). Thus, the mutant channel K95S/S1141K showed Cl− conductance and open-channel blocker interactions similar to those of wild-type CFTR, thereby “rescuing” the effects of the charge-neutralizing K95S mutation. Furthermore, the function of K95C/S1141C, but not K95C or S1141C, was inhibited by the oxidizing agent copper(II)-o-phenanthroline, and this inhibition was reversed by the reducing agent dithiothreitol, suggesting disulfide bond formation between these two introduced cysteine side chains. These results suggest that the amino acid side chains of K95 (in TM1) and S1141 (in TM12) are functionally interchangeable and located closely together in the inner vestibule of the pore. This allowed us to investigate the functional effects of increasing the number of fixed positive charges in this vestibule from one (in wild type) to two (in the S1141K mutant). The S1141K mutant had similar Cl− conductance as wild type, but increased susceptibility to channel block by cytoplasmic anions including adenosine triphosphate, pyrophosphate, 5-nitro-2-(3-phenylpropylamino)benzoic acid, and Pt(NO2)42− in inside-out membrane patches. Furthermore, in cell-attached patch recordings, apparent voltage-dependent channel block by cytosolic anions was strengthened by the S1141K mutation. Thus, the Cl− channel function of CFTR is maximal with a single fixed positive charge in this part of the inner vestibule of the pore, and increasing the number of such charges to two causes a net decrease in overall Cl− transport through a

  20. Regulation of conductance by the number of fixed positive charges in the intracellular vestibule of the CFTR chloride channel pore.

    PubMed

    Zhou, Jing-Jun; Li, Man-Song; Qi, Jiansong; Linsdell, Paul

    2010-03-01

    Rapid chloride permeation through the cystic fibrosis transmembrane conductance regulator (CFTR) Cl(-) channel is dependent on the presence of fixed positive charges in the permeation pathway. Here, we use site-directed mutagenesis and patch clamp recording to show that the functional role played by one such positive charge (K95) in the inner vestibule of the pore can be "transplanted" to a residue in a different transmembrane (TM) region (S1141). Thus, the mutant channel K95S/S1141K showed Cl(-) conductance and open-channel blocker interactions similar to those of wild-type CFTR, thereby "rescuing" the effects of the charge-neutralizing K95S mutation. Furthermore, the function of K95C/S1141C, but not K95C or S1141C, was inhibited by the oxidizing agent copper(II)-o-phenanthroline, and this inhibition was reversed by the reducing agent dithiothreitol, suggesting disulfide bond formation between these two introduced cysteine side chains. These results suggest that the amino acid side chains of K95 (in TM1) and S1141 (in TM12) are functionally interchangeable and located closely together in the inner vestibule of the pore. This allowed us to investigate the functional effects of increasing the number of fixed positive charges in this vestibule from one (in wild type) to two (in the S1141K mutant). The S1141K mutant had similar Cl(-) conductance as wild type, but increased susceptibility to channel block by cytoplasmic anions including adenosine triphosphate, pyrophosphate, 5-nitro-2-(3-phenylpropylamino)benzoic acid, and Pt(NO(2))(4)(2-) in inside-out membrane patches. Furthermore, in cell-attached patch recordings, apparent voltage-dependent channel block by cytosolic anions was strengthened by the S1141K mutation. Thus, the Cl(-) channel function of CFTR is maximal with a single fixed positive charge in this part of the inner vestibule of the pore, and increasing the number of such charges to two causes a net decrease in overall Cl(-) transport through a

  1. p32, a novel binding partner of Mcl-1, positively regulates mitochondrial Ca{sup 2+} uptake and apoptosis

    SciTech Connect

    Xiao, Kang; Wang, Yinyin; Chang, Zhijie; Lao, Yuanzhi; Chang, Donald C.

    2014-08-22

    Highlights: • p32 binds to Mcl-1. • p32 affects apoptosis. • p32 and Mcl-1 regulate mitochondrial Ca{sup 2+}. - Abstract: Mcl-1 is a major anti-apoptotic Bcl-2 family protein. It is well known that Mcl-1 can interact with certain pro-apoptotic Bcl-2 family proteins in normal cells to neutralize their pro-apoptotic functions, thus prevent apoptosis. In addition, it was recently found that Mcl-1 can also inhibit mitochondrial calcium uptake. The detailed mechanism, however, is still not clear. Based on Yeast Two-Hybrid screening and co-immunoprecipitation, we identified a mitochondrial protein p32 (C1qbp) as a novel binding partner of Mcl-1. We found that p32 had a number of interesting properties: (1) p32 can positively regulate UV-induced apoptosis in HeLa cells. (2) Over-expressing p32 could significantly promote mitochondrial calcium uptake, while silencing p32 by siRNA suppressed it. (3) In p32 knockdown cells, Ruthenium Red treatment (an inhibitor of mitochondrial calcium uniporter) showed no further suppressive effect on mitochondrial calcium uptake. In addition, in Ruthenium Red treated cells, Mcl-1 also failed to suppress mitochondrial calcium uptake. Taken together, our findings suggest that p32 is part of the putative mitochondrial uniporter that facilitates mitochondrial calcium uptake. By binding to p32, Mcl-1 can interfere with the uniporter function, thus inhibit the mitochondrial Ca{sup 2+} uploading. This may provide a novel mechanism to explain the anti-apoptotic function of Mcl-1.

  2. Deciphering the Regulon of Streptomyces coelicolor AbrC3, a Positive Response Regulator of Antibiotic Production

    PubMed Central

    Rico, Sergio; Santamaría, Ramón I.; Yepes, Ana; Rodríguez, Héctor; Laing, Emma; Bucca, Giselda; Smith, Colin P.

    2014-01-01

    The atypical two-component system (TCS) AbrC1/C2/C3 (encoded by SCO4598, SCO4597, and SCO4596), comprising two histidine kinases (HKs) and a response regulator (RR), is crucial for antibiotic production in Streptomyces coelicolor and for morphological differentiation under certain nutritional conditions. In this study, we demonstrate that deletion of the RR-encoding gene, abrC3 (SCO4596), results in a dramatic decrease in actinorhodin (ACT) and undecylprodiginine (RED) production and delays morphological development. In contrast, the overexpression of abrC3 in the parent strain leads to a 33% increase in ACT production in liquid medium. Transcriptomic analysis and chromatin immunoprecipitation with microarray technology (ChIP-chip) analysis of the ΔabrC3 mutant and the parent strain revealed that AbrC3 directly controls ACT production by binding to the actII-ORF4 promoter region; this was independently verified by in vitro DNA-binding assays. This binding is dependent on the sequence 5′-GAASGSGRMS-3′. In contrast, the regulation of RED production is not due to direct binding of AbrC3 to either the redZ or redD promoter region. This study also revealed other members of the AbrC3 regulon: AbrC3 is a positive autoregulator which also binds to the promoter regions of SCO0736, bdtA (SCO3328), absR1 (SCO6992), and SCO6809. The direct targets share the 10-base consensus binding sequence and may be responsible for some of the phenotypes of the ΔabrC3 mutant. The identification of the AbrC3 regulon as part of the complex regulatory network governing antibiotic production widens our knowledge regarding TCS involvement in control of antibiotic synthesis and may contribute to the rational design of new hyperproducer host strains through genetic manipulation of such systems. PMID:24509929

  3. Methionine adenosyltransferase α2 sumoylation positively regulate Bcl-2 expression in human colon and liver cancer cells

    PubMed Central

    Tomasi, Maria Lauda; Ryoo, Minjung; Ramani, Komal; Tomasi, Ivan; Giordano, Pasquale; Mato, José M.; Lu, Shelly C.

    2015-01-01

    Ubiquitin-conjugating enzyme 9 (Ubc9) is required for sumoylation and inhibits apoptosis via Bcl-2 by unknown mechanism. Methionine adenosyltransferase 2A (MAT2A) encodes for MATα2, the catalytic subunit of the MATII isoenzyme that synthesizes S-adenosylmethionine (SAMe). Ubc9, Bcl-2 and MAT2A expression are up-regulated in several malignancies. Exogenous SAMe decreases Ubc9 and MAT2A expression and is pro-apoptotic in liver and colon cancer cells. Here we investigated whether there is interplay between Ubc9, MAT2A and Bcl-2. We used human colon and liver cancer cell lines RKO and HepG2, respectively, and confirmed key finding in colon cancer specimens. We found MATα2 can regulate Bcl-2 expression at multiple levels. MATα2 binds to Bcl-2 promoter to activate its transcription. This effect is independent of SAMe as MATα2 catalytic mutant was also effective. MATα2 also directly interacts with Bcl-2 to enhance its protein stability. MATα2's effect on Bcl-2 requires Ubc9 as MATα2's stability is influenced by sumoylation at K340, K372 and K394. Overexpressing wild type (but not less stable MATα2 sumoylation mutants) protected from 5-fluorouracil-induced apoptosis in both colon and liver cancer cells. Colon cancer have higher levels of sumoylated MATα2, total MATα2, Ubc9 and Bcl-2 and higher MATα2 binding to the Bcl-2 P2 promoter. Taken together, Ubc9's protective effect on apoptosis may be mediated at least in part by sumoylating and stabilizing MATα2 protein, which in turn positively maintains Bcl-2 expression. These interactions feed forward to further enhance growth and survival of the cancer cell. PMID:26416353

  4. Nuclear Protein Sam68 Interacts with the Enterovirus 71 Internal Ribosome Entry Site and Positively Regulates Viral Protein Translation

    PubMed Central

    Zhang, Hua; Song, Lei; Cong, Haolong

    2015-01-01

    ABSTRACT Enterovirus 71 (EV71) recruits various cellular factors to assist in the replication and translation of its genome. Identification of the host factors involved in the EV71 life cycle not only will enable a better understanding of the infection mechanism but also has the potential to be of use in the development of antiviral therapeutics. In this study, we demonstrated that the cellular factor 68-kDa Src-associated protein in mitosis (Sam68) acts as an internal ribosome entry site (IRES) trans-acting factor (ITAF) that binds specifically to the EV71 5′ untranslated region (5′UTR). Interaction sites in both the viral IRES (stem-loops IV and V) and the heterogeneous nuclear ribonucleoprotein K homology (KH) domain of Sam68 protein were further mapped using an electrophoretic mobility shift assay (EMSA) and biotin RNA pulldown assay. More importantly, dual-luciferase (firefly) reporter analysis suggested that overexpression of Sam68 positively regulated IRES-dependent translation of virus proteins. In contrast, both IRES activity and viral protein translation significantly decreased in Sam68 knockdown cells compared with the negative-control cells treated with short hairpin RNA (shRNA). However, downregulation of Sam68 did not have a significant inhibitory effect on the accumulation of the EV71 genome. Moreover, Sam68 was redistributed from the nucleus to the cytoplasm and interacts with cellular factors, such as poly(rC)-binding protein 2 (PCBP2) and poly(A)-binding protein (PABP), during EV71 infection. The cytoplasmic relocalization of Sam68 in EV71-infected cells may be involved in the enhancement of EV71 IRES-mediated translation. Since Sam68 is known to be a RNA-binding protein, these results provide direct evidence that Sam68 is a novel ITAF that interacts with EV71 IRES and positively regulates viral protein translation. IMPORTANCE The nuclear protein Sam68 is found as an additional new host factor that interacts with the EV71 IRES during infection

  5. Intentional Self-Regulation and Positive Youth Development in Early Adolescence: Findings from the 4-H Study of Positive Youth Development

    ERIC Educational Resources Information Center

    Gestsdottir, Steinunn; Lerner, Richard M.

    2007-01-01

    In this research, the authors examined the development of intentional self-regulation in early adolescence, which was operationalized through the use of a measure derived from the model of selection, optimization, and compensation (SOC). This model describes the individual's contributions to mutually influential relations between the person and…

  6. Regulation of glycoprotein D synthesis: does alpha 4, the major regulatory protein of herpes simplex virus 1, regulate late genes both positively and negatively?

    PubMed Central

    Arsenakis, M; Campadelli-Fiume, G; Roizman, B

    1988-01-01

    Earlier studies have described the alpha 4/c113 baby hamster kidney cell line which constitutively expresses the alpha 4 protein, the major regulatory protein of herpes simplex virus 1 (HSV-1). Introduction of the HSV-1 glycoprotein B (gB) gene, regulated as a gamma 1 gene, into these cells yielded a cell line which constitutively expressed both the alpha 4 and gamma 1 gB genes. The expression of the gB gene was dependent on the presence of functional alpha 4 protein. In this article we report that we introduced into the alpha 4/c113 and into the parental BHK cells, the HSV-1 BamHI J fragment, which encodes the domains of four genes, including those of glycoproteins D, G, and I (gD, gG, and gI), and most of the coding sequences of the glycoprotein E (gE) gene. In contrast to the earlier studies, we obtained significant constitutive expression of gD (also a gamma 1 gene) in a cell line (BJ) derived from parental BHK cells, but not in a cell line (alpha 4/BJ) which expresses functional alpha 4 protein. RNA homologous to the gD gene was present in significant amounts in the BJ cell line; smaller amounts of this RNA were detected in the alpha 4/BJ cell line. RNA homologous to gE, presumed to be polyadenylated from signals in the vector sequences, was present in the BJ cells but not in the alpha 4/BJ cells. The expression of the HSV-1 gD and gE genes was readily induced in the alpha 4/BJ cells by superinfection with HSV-2. The BJ cell line was, in contrast, resistant to expression of HSV-1 and HSV-2 genes. The BamHI J DNA fragment copy number was approximately 1 per BJ cell genome equivalent and 30 to 50 per alpha 4/BJ cell genome equivalent. We conclude that (i) the genes specifying gD and gB belong to different viral regulatory gene subsets, (ii) the gD gene is subject to both positive and negative regulation, (iii) both gD and gE mRNAs are subject to translational controls although they may be different, and (iv) the absence of expression of gD in the alpha 4/BJ

  7. A FRET-based study reveals site-specific regulation of spindle position checkpoint proteins at yeast centrosomes.

    PubMed

    Gryaznova, Yuliya; Koca Caydasi, Ayse; Malengo, Gabriele; Sourjik, Victor; Pereira, Gislene

    2016-01-01

    The spindle position checkpoint (SPOC) is a spindle pole body (SPB, equivalent of mammalian centrosome) associated surveillance mechanism that halts mitotic exit upon spindle mis-orientation. Here, we monitored the interaction between SPB proteins and the SPOC component Bfa1 by FRET microscopy. We show that Bfa1 binds to the scaffold-protein Nud1 and the γ-tubulin receptor Spc72. Spindle misalignment specifically disrupts Bfa1-Spc72 interaction by a mechanism that requires the 14-3-3-family protein Bmh1 and the MARK/PAR-kinase Kin4. Dissociation of Bfa1 from Spc72 prevents the inhibitory phosphorylation of Bfa1 by the polo-like kinase Cdc5. We propose Spc72 as a regulatory hub that coordinates the activity of Kin4 and Cdc5 towards Bfa1. In addition, analysis of spc72∆ cells shows that a mitotic-exit-promoting dominant signal, which is triggered upon elongation of the spindle into the bud, overrides the SPOC. Our data reinforce the importance of daughter-cell-associated factors and centrosome-based regulations in mitotic exit and SPOC control. PMID:27159239

  8. Regulation of transcription by eukaryotic-like serine-threonine kinases and phosphatases in Gram-positive bacterial pathogens

    PubMed Central

    Wright, David P; Ulijasz, Andrew T

    2014-01-01

    Bacterial eukaryotic-like serine threonine kinases (eSTKs) and serine threonine phosphatases (eSTPs) have emerged as important signaling elements that are indispensable for pathogenesis. Differing considerably from their histidine kinase counterparts, few eSTK genes are encoded within the average bacterial genome, and their targets are pleiotropic in nature instead of exclusive. The growing list of important eSTK/P substrates includes proteins involved in translation, cell division, peptidoglycan synthesis, antibiotic tolerance, resistance to innate immunity and control of virulence factors. Recently it has come to light that eSTK/Ps also directly modulate transcriptional machinery in many microbial pathogens. This novel form of regulation is now emerging as an additional means by which bacteria can alter their transcriptomes in response to host-specific environmental stimuli. Here we focus on the ability of eSTKs and eSTPs in Gram-positive bacterial pathogens to directly modulate transcription, the known mechanistic outcomes of these modifications, and their roles as an added layer of complexity in controlling targeted RNA synthesis to enhance virulence potential. PMID:25603430

  9. Histone demethylase KDM5A is regulated by its reader domain through a positive-feedback mechanism

    NASA Astrophysics Data System (ADS)

    Torres, Idelisse Ortiz; Kuchenbecker, Kristopher M.; Nnadi, Chimno I.; Fletterick, Robert J.; Kelly, Mark J. S.; Fujimori, Danica Galonić

    2015-02-01

    The retinoblastoma binding protein KDM5A removes methyl marks from lysine 4 of histone H3 (H3K4). Misregulation of KDM5A contributes to the pathogenesis of lung and gastric cancers. In addition to its catalytic jumonji C domain, KDM5A contains three PHD reader domains, commonly recognized as chromatin recruitment modules. It is unknown whether any of these domains in KDM5A have functions beyond recruitment and whether they regulate the catalytic activity of the demethylase. Here using biochemical and nuclear magnetic resonance (NMR)-based structural studies, we show that the PHD1 preferentially recognizes unmethylated H3K4 histone tail, product of KDM5A-mediated demethylation of tri-methylated H3K4 (H3K4me3). Binding of unmodified H3 peptide to the PHD1 stimulates catalytic domain-mediated removal of methyl marks from H3K4me3 peptide and nucleosome substrates. This positive-feedback mechanism—enabled by the functional coupling between a reader and a catalytic domain in KDM5A—suggests a model for the spread of demethylation on chromatin.

  10. Glioma-derived plasminogen activator inhibitor-1 (PAI-1) regulates the recruitment of LRP1 positive mast cells.

    PubMed

    Roy, Ananya; Coum, Antoine; Marinescu, Voichita D; Põlajeva, Jelena; Smits, Anja; Nelander, Sven; Uhrbom, Lene; Westermark, Bengt; Forsberg-Nilsson, Karin; Pontén, Fredrik; Tchougounova, Elena

    2015-09-15

    Glioblastoma (GBM) is a high-grade glioma with a complex microenvironment, including various inflammatory cells and mast cells (MCs) as one of them. Previously we had identified glioma grade-dependent MC recruitment. In the present study we investigated the role of plasminogen activator inhibitor 1 (PAI-1) in MC recruitment.PAI-1, a primary regulator in the fibrinolytic cascade is capable of forming a complex with fibrinolytic system proteins together with low-density lipoprotein receptor-related protein 1 (LRP1). We found that neutralizing PAI-1 attenuated infiltration of MCs. To address the potential implication of LRP1 in this process, we used a LRP1 antagonist, receptor-associated protein (RAP), and demonstrated the attenuation of MC migration. Moreover, a positive correlation between the number of MCs and the level of PAI-1 in a large cohort of human glioma samples was observed. Our study demonstrated the expression of LRP1 in human MC line LAD2 and in MCs in human high-grade glioma. The activation of potential PAI-1/LRP1 axis with purified PAI-1 promoted increased phosphorylation of STAT3 and subsequently exocytosis in MCs.These findings indicate the influence of the PAI-1/LRP1 axis on the recruitment of MCs in glioma. The connection between high-grade glioma and MC infiltration could contribute to patient tailored therapy and improve patient stratification in future therapeutic trials. PMID:26164207