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Sample records for mori cadherin receptor

  1. Binding specificity of Bacillus thuringiensis Cry1Aa for purified, native Bombyx mori aminopeptidase N and cadherin-like receptors

    PubMed Central

    Jenkins, Jeremy L; Dean, Donald H

    2001-01-01

    Background To better understand the molecular interactions of Bt toxins with non-target insects, we have examined the real-time binding specificity and affinity of Cry1 toxins to native silkworm (Bombyx mori) midgut receptors. Previous studies on B. mori receptors utilized brush border membrane vesicles or purifed receptors in blot-type assays. Results The Bombyx mori (silkworm) aminopeptidase N (APN) and cadherin-like receptors for Bacillus thuringiensis insecticidal Cry1Aa toxin were purified and their real-time binding affinities for Cry toxins were examined by surface plasmon resonance. Cry1Ab and Cry1Ac toxins did not bind to the immobilized native receptors, correlating with their low toxicities. Cry1Aa displayed moderate affinity for B. mori APN (75 nM), and unusually tight binding to the cadherin-like receptor (2.6 nM), which results from slow dissociation rates. The binding of a hybrid toxin (Aa/Aa/Ac) was identical to Cry1Aa. Conclusions These results indicate domain II of Cry1Aa is essential for binding to native B. mori receptors and for toxicity. Moreover, the high-affinity binding of Cry1Aa to native cadherin-like receptor emphasizes the importance of this receptor class for Bt toxin research. PMID:11722800

  2. Blocking binding of Bacillus thuringiensis Cry1Aa to Bombyx mori cadherin receptor results in only a minor reduction of toxicity

    PubMed Central

    You, Taek H; Lee, Mi K; Jenkins, Jeremy L; Alzate, Oscar; Dean, Donald H

    2008-01-01

    Background Bacillus thuringiensis Cry1Aa insecticidal protein is the most active known B. thuringiensis toxin against the forest insect pest Lymantria dispar (gypsy moth), unfortunately it is also highly toxic against the non-target insect Bombyx mori (silk worm). Results Surface exposed hydrophobic residues over domains II and III were targeted for site-directed mutagenesis. Substitution of a phenylalanine residue (F328) by alanine reduced binding to the Bombyx mori cadherin by 23-fold, reduced biological activity against B. mori by 4-fold, while retaining activity against Lymantria dispar. Conclusion The results identify a novel receptor-binding epitope and demonstrate that virtual elimination of binding to cadherin BR-175 does not completely remove toxicity in the case of B. mori. PMID:18218126

  3. A cadherin-like protein functions as a receptor for Bacillus thuringiensis Cry1Aa and Cry1Ac toxins on midgut epithelial cells of Bombyx mori larvae.

    PubMed

    Hara, Hirotaka; Atsumi, Shogo; Yaoi, Katsuro; Nakanishi, Kazuko; Higurashi, Satoshi; Miura, Nami; Tabunoki, Hiroko; Sato, Ryoichi

    2003-03-13

    Aminopeptidase N (APN) and cadherin-like protein (BtR175) from Bombyx mori larvae were examined for their roles in Cry1Aa- and Cry1Ac-induced lysis of B. mori midgut epithelial cells (MECs). APNs and BtR175 were present in all areas of the midgut, were particularly abundant in the posterior region, and were found only on columnar cell microvilli and not on the lateral membrane that makes cell-cell contacts. This distribution was in accordance with the distribution of Cry1A-susceptible MECs in the midgut. The lytic activity of Cry1Aa and Cry1Ac on collagenase-dissociated MECs was linearly dependent on toxin concentration. Although pre-treatment of MECs with anti-BtR175 antibody was observed to partially inhibit the lytic activity exerted by 0.1-1 nM Cry1Aa toxin or 5 nM Cry1Ac toxin, no significant inhibition was observed when MECs were pre-treated with anti-APN antibody. These results suggest that BtR175 functions as a major receptor for Cry1A toxins in the midgut of B. mori larvae. PMID:12633848

  4. Cytotoxic activity of Bacillus thuringiensis Cry proteins on mammalian cells transfected with cadherin-like Cry receptor gene of Bombyx mori (silkworm).

    PubMed Central

    Tsuda, Yoko; Nakatani, Fumiki; Hashimoto, Keiko; Ikawa, Satoshi; Matsuura, Chikako; Fukada, Takashi; Sugimoto, Kenji; Himeno, Michio

    2003-01-01

    Cry1Aa, an insecticidal protein produced by Bacillus thuringiensis, has been shown to bind to cadherin-like protein, BtR175, in Bombyx mori (silkworm) midgut. We previously reported three variant alleles of BtR175 (BtR175a, b and c). When transiently expressed in COS7 cells, all the three BtR175 variants bound to Cry1Aa. We stably expressed BtR175b in HEK293 cells. These BtR175b-expressing cells swelled and died in the presence of activated Cry1Aa in a dose- and time-dependent manner, showing that BtR175b itself can impart Cry1Aa-susceptibility to mammalian cells. These cells were more susceptible to Cry1Aa than to Cry1Ab and Cry1Ac. Since dispersed B. mori midgut cells were reported to be highly susceptible to Cry1Ac, this result suggested that other Cry1Ac-specific receptor(s) were simultaneously working with BtR175 in the midgut cells. Advantages are also discussed of applying these transfected mammalian cells to toxicity assays of mutant Cry proteins. PMID:12403648

  5. Flamingo cadherin: a putative host receptor for Streptococcus pneumoniae.

    PubMed

    Blau, Karin; Portnoi, Maxim; Shagan, Marilou; Kaganovich, Antonina; Rom, Slava; Kafka, Daniel; Chalifa Caspi, Vered; Porgador, Angel; Givon-Lavi, Noga; Gershoni, Jonathan M; Dagan, Ron; Mizrachi Nebenzahl, Yaffa

    2007-06-15

    Streptococcus pneumoniae fructose bisphosphate aldolase (FBA) is a cell wall-localized lectin. We demonstrate that recombinant (r) FBA and anti-rFBA antibodies inhibit encapsulated and unencapsulated S. pneumoniae serotype 3 adherence to A549 type II lung carcinoma epithelial cells. A random combinatorial peptide library expressed by filamentous phage was screened with rFBA. Eleven of 30 rFBA-binding phages inhibited 90% of S. pneumoniae adhesion to A549 cells. The insert peptide sequence of 9 of these phages matched the Flamingo cadherin receptor (FCR) when aligned against the human genome. A peptide comprising a putative FBA-binding region of FCR (FCRP) inhibited 2 genetically and capsularly unrelated pairs of encapsulated and unencapsulated S. pneumoniae strains from binding to A549 cells. Moreover, FCRP inhibited S. pneumoniae nasopharyngeal and lung colonization and, possibly, pneumonia development in the mouse intranasal inoculation model system. These data indicate that FBA is an S. pneumoniae adhesin and that FCR is its host receptor. PMID:17492599

  6. Sphingosine 1-phosphate receptor regulation of N-cadherin mediates vascular stabilization

    PubMed Central

    Paik, Ji-Hye; Skoura, Athanasia; Chae, Sung-Suk; Cowan, Ann E.; Han, David K.; Proia, Richard L.; Hla, Timothy

    2004-01-01

    Vascular stabilization, a process by which nascent vessels are invested with mural cells, is important in angiogenesis. Here we describe the molecular basis of vascular stabilization regulated by sphingosine 1-phosphate (S1P), a platelet-derived lipid mediator. S1P1 receptor-dependent cell-surface trafficking and activation of the cell-cell adhesion molecule N-cadherin is essential for interactions between endothelial and mural cells. Endothelial cell S1P1/Gi/Rac pathway induces microtubule polymerization, resulting in trafficking of N-cadherin to polarized plasma membrane domains. S1P treatment modulated the phosphorylation of N-cadherin as well as p120-catenin and induced the formation of cadherin/catenin/actin complexes containing novel regulatory and trafficking factors. The net result of endothelial cell S1P1 receptor activation is the proper trafficking and strengthening of N-cadherin-dependent cell-cell adhesion with mural cells. Perturbation of N-cadherin expression with small interfering RNA profoundly attenuated vascular stabilization in vitro and in vivo. S1P-induced trafficking and activation of N-cadherin provides a novel mechanism for the stabilization of nascent blood vessels by mural cells and may be exploited to control angiogenesis and vascular diseases. PMID:15371328

  7. A novel Tenebrio molitor cadherin is a functional receptor for Bacillus thuringiensis Cry3Aa toxin.

    PubMed

    Fabrick, Jeff; Oppert, Cris; Lorenzen, Marcé D; Morris, Kaley; Oppert, Brenda; Jurat-Fuentes, Juan Luis

    2009-07-01

    Cry toxins produced by the bacterium Bacillus thuringiensis are effective biological insecticides. Cadherin-like proteins have been reported as functional Cry1A toxin receptors in Lepidoptera. Here we present data that demonstrate that a coleopteran cadherin is a functional Cry3Aa toxin receptor. The Cry3Aa receptor cadherin was cloned from Tenebrio molitor larval midgut mRNA, and the predicted protein, TmCad1, has domain structure and a putative toxin binding region similar to those in lepidopteran cadherin B. thuringiensis receptors. A peptide containing the putative toxin binding region from TmCad1 bound specifically to Cry3Aa and promoted the formation of Cry3Aa toxin oligomers, proposed to be mediators of toxicity in lepidopterans. Injection of TmCad1-specific double-stranded RNA into T. molitor larvae resulted in knockdown of the TmCad1 transcript and conferred resistance to Cry3Aa toxicity. These data demonstrate the functional role of TmCad1 as a Cry3Aa receptor in T. molitor and reveal similarities between the mode of action of Cry toxins in Lepidoptera and Coleoptera. PMID:19416969

  8. A Novel Tenebrio molitor Cadherin is a Functional Receptor for Bacillus thuringiensis Toxin Cry3Aa

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Cry toxins produced by the bacterium Bacillus thuringiensis (Bt) are effective biological insecticides. Cadherin-like proteins have been reported as functional Cry1A toxin receptors in Lepidoptera. We present the first report demonstrating a functional interaction between the coleopteran-specific ...

  9. Gene expression and localization analysis of Bombyx mori bidensovirus and its putative receptor in B. mori midgut.

    PubMed

    Ito, Katsuhiko; Shimura, Sachiko; Katsuma, Susumu; Tsuda, Yasuhiro; Kobayashi, Jun; Tabunoki, Hiroko; Yokoyama, Takeshi; Shimada, Toru; Kadono-Okuda, Keiko

    2016-05-01

    Bombyx mori bidensovirus (BmBDV), which causes fatal flacherie disease in the silkworm, replicates only in midgut columnar cells. The viral resistance expressed by some silkworm strains, which is characterized as non-susceptibility irrespective of the viral dose, is determined by a single gene, nsd-2. We previously identified nsd-2 by positional cloning and found that this gene encodes a putative amino acid transporter that might function as a receptor for BmBDV. In this study, we investigated the relationship between the part of the midgut expressing nsd-2 (resistance gene), +(nsd-2) (susceptibility gene) and BmBDV propagation. Quantitative RT-PCR (qRT-PCR) analysis using total RNA isolated from the anterior, middle, and posterior parts of the midgut showed that nsd-2 and +(nsd-2) were strongly expressed in the posterior part of the midgut. The expression levels of both genes were very low in the anterior and middle parts. The qRT-PCR analysis showed that the expression levels of BmBDV-derived transcripts were correlated with the levels of +(nsd-2) expression. However, BmBDV-derived transcripts were clearly detected in all parts of the midgut. These results suggest that the infectivity of BmBDV depends mainly on the expression level of +(nsd-2) in the midgut and that viral infection is supported even by very faint expression of +(nsd-2). By contrast, the expression levels of +(nsd-2) were exceedingly low or undetectable in the middle part of the midgut, indicating that BmBDV infection might occur via another mechanism, independent of +(nsd-2), in the middle part of the midgut. PMID:26953258

  10. Orthologs of Human Disease Associated Genes and RNAi Analysis of Silencing Insulin Receptor Gene in Bombyx mori

    PubMed Central

    Zhang, Zan; Teng, Xiaolu; Chen, Maohua; Li, Fei

    2014-01-01

    The silkworm, Bombyx mori L., is an important economic insect that has been domesticated for thousands of years to produce silk. It is our great interest to investigate the possibility of developing the B. mori as human disease model. We searched the orthologs of human disease associated genes in the B. mori by bi-directional best hits of BLAST and confirmed by searching the OrthoDB. In total, 5006 genes corresponding to 1612 kinds of human diseases had orthologs in the B. mori, among which, there are 25 genes associated with diabetes mellitus. Of these, we selected the insulin receptor gene of the B. mori (Bm-INSR) to study its expression in different tissues and at different developmental stages and tissues. Quantitative PCR showed that Bm-INSR was highly expressed in the Malpighian tubules but expressed at low levels in the testis. It was highly expressed in the 3rd and 4th instar larvae, and adult. We knocked down Bm-INSR expression using RNA interference. The abundance of Bm-INSR transcripts were dramatically reduced to ~4% of the control level at 6 days after dsRNA injection and the RNAi-treated B. mori individuals showed apparent growth inhibition and malformation such as abnormal body color in black, which is the typical symptom of diabetic patients. Our results demonstrate that B. mori has potential use as an animal model for diabetic mellitus research. PMID:25302617

  11. In situ phosphorylation of immobilized receptors on biosensor surfaces: application to E-cadherin/beta-catenin interactions.

    PubMed

    Catimel, Bruno; Layton, Meredith; Church, Nicole; Ross, Janine; Condron, Melanie; Faux, Maree; Simpson, Richard J; Burgess, Antony W; Nice, Edouard C

    2006-10-15

    Phosphorylation is a key posttranslational modification for modulating biological interactions. Biosensor technology is ideally suited for examining in real time the role of phosphorylation on protein-protein interactions in signaling pathways. We have developed processes for on-chip phosphorylation of immobilized receptors on biosensor surfaces. These processes have been used to analyze E-cadherin/beta-catenin interactions. Phosphorylation of the intracellular domain (ICD) of E-cadherin modulates its affinity to beta-catenin and consequently the strength of cell-cell adhesion. We have phosphorylated immobilized E-cadherin ICD in situ using casein kinase 1 (CK1), casein kinase 2 (CK2), and src. On-chip phosphorylation of E-cadherin was confirmed using anti-phosphoserine and anti-phosphotyrosine antibodies. The binding of beta-catenin to E-cadherin was analyzed quantitatively. CK1 phosphorylation of E-cadherin increased the binding affinity to beta-catenin from approximately 230 to 4 nM. A similar increase in affinity, from 260 to 4 nM, was obtained with CK2 phosphorylation of E-cadherin. However, phosphorylation by src kinase decreased the affinity constant from approximately 260 nM to 4 microM. Interestingly, phosphorylation of E-cadherin by CK1 or CK2 prevented the inhibition of beta-catenin binding by src phosphorylation. PMID:16945320

  12. The ionotropic γ-aminobutyric acid receptor gene family of the silkworm, Bombyx mori.

    PubMed

    Yu, Lin-Lin; Cui, Ying-Jun; Lang, Guo-Jun; Zhang, Ming-Yan; Zhang, Chuan-Xi

    2010-09-01

    γ-Aminobutyric acid (GABA) is a very important inhibitory neurotransmitter in both vertebrate and invertebrate nervous systems. GABA receptors (GABARs) are known to be the molecular targets of a class of insecticides. Members of the GABAR gene family of the silkworm, Bombyx mori, a model insect of Lepidoptera, have been identified and characterized in this study. All putative silkworm GABAR cDNAs were cloned using the reverse transcriptase polymerase chain reaction (RT-PCR) and rapid amplification of cDNA ends (RACE). Bombyx mori appears to have the largest insect GABAR gene family known to date, including three RDL, one LCCH3, and one GRD subunit. The silkworm RDL1 gene has RNA-editing sites, and the RDL1 and RDL3 genes possess alternative splicing. These mRNA modifications enhance the diversity of the silkworm's GABAR gene family. In addition, truncated transcripts were found for the RDL1 and LCCH3 genes. In particular, the three RDL subunits may have arisen from two duplication events. PMID:20924418

  13. Understanding cadherin EGF LAG seven-pass G-type receptors.

    PubMed

    Wang, Xiao-Jing; Zhang, Dao-Lai; Xu, Zhi-Gang; Ma, Ming-Liang; Wang, Wen-Bo; Li, Lin-Lin; Han, Xiao-Lin; Huo, Yuqing; Yu, Xiao; Sun, Jin-Peng

    2014-12-01

    The cadherin epidermal growth factor (EGF) laminin G (LAG) seven-pass G-type receptors (CELSRs) are a special subgroup of adhesion G protein-coupled receptors, which are pivotal regulators of many biologic processes such as neuronal/endocrine cell differentiation, vessel valve formation, and the control of planar cell polarity during embryonic development. All three members of the CELSR family (CELSR1-3) have large ecto-domains that form homophilic interactions and encompass more than 2000 amino acids. Mutations in the ecto-domain or other gene locations of CELSRs are associated with neural tube defects and other diseases in humans. Celsr knockout (KO) animals have many developmental defects. Therefore, specific agonists or antagonists of CELSR members may have therapeutic potential. Although significant progress has been made regarding the functions and biochemical properties of CELSRs, our knowledge of these receptors is still lacking, especially considering that they are broadly distributed but have few characterized functions in a limited number of tissues. The dynamic activation and inactivation of CELSRs and the presence of endogenous ligands beyond homophilic interactions remain elusive, as do the regulatory mechanisms and downstream signaling of these receptors. Given this motivation, future studies with more advanced cell biology or biochemical tools, such as conditional KO mice, may provide further insights into the mechanisms underlying CELSR function, laying the foundation for the design of new CELSR-targeted therapeutic reagents. The cadherin EGF LAG seven-pass G-type receptors (CELSRs) are a special subgroup of adhesion G protein-coupled receptors (GPCRs), which have large ecto-domains that form homophilic interactions and encompass more than 2000 amino acids. Recent studies have revealed that CELSRs are pivotal regulators of many biological processes, such as neuronal/endocrine cell differentiation, vessel valve formation and the control of planar

  14. The P2Y2 Receptor Interacts with VE-Cadherin and VEGF Receptor-2 to Regulate Rac1 Activity in Endothelial Cells

    PubMed Central

    Liao, Zhongji; Cao, Chen; Wang, Jianjie; Huxley, Virginia H.; Baker, Olga; Weisman, Gary A.

    2015-01-01

    Vascular endothelial cadherin (VE-cadherin) mediates homophylic adhesion between endothelial cells and is an important regulator of angiogenesis, blood vessel permeability and leukocyte trafficking. Rac1, a member of the Rho family of GTPases, controls VE-cadherin adhesion by acting downstream of several growth factors, including angiopoietin-1 and vascular endothelial growth factor (VEGF). Here we show that UTP-induced activation of the Gq protein-coupled P2Y2 nucleotide receptor (P2Y2R) in human coronary artery endothelial cells (HCAECs) activated Rac1 and caused a transient complex to form between P2Y2R, VE-cadherin and VEGF receptor-2 (VEGFR-2). Knockdown of VE-cadherin expression with siRNA did not affect UTP-induced activation of extracellular signal-regulated kinases 1/2 (ERK1/2) but led to a loss of UTP-induced Rac1 activation and tyrosine phosphorylation of p120 catenin, a cytoplasmic protein known to interact with VE-cadherin. Activation of the P2Y2R by UTP also caused a prolonged interaction between p120 catenin and vav2 (a guanine nucleotide exchange factor for Rac) that correlated with the kinetics of UTP-induced tyrosine phosphorylation of p120 catenin and VE-cadherin. Inhibitors of VEGFR-2 (SU1498) or Src (PP2) significantly diminished UTP-induced Rac1 activation, tyrosine phosphorylation of p120 catenin and VE-cadherin, and association of the P2Y2R with VE-cadherin and p120 catenin with vav2. These findings suggest that the P2Y2R uses Src and VEGFR-2 to mediate association of the P2Y2R with VE-cadherin complexes in endothelial adherens junctions to activate Rac1. PMID:25657827

  15. Combinatory annotation of cell membrane receptors and signalling pathways of Bombyx mori prothoracic glands.

    PubMed

    Moulos, Panagiotis; Samiotaki, Martina; Panayotou, George; Dedos, Skarlatos G

    2016-01-01

    The cells of prothoracic glands (PG) are the main site of synthesis and secretion of ecdysteroids, the biochemical products of cholesterol conversion to steroids that shape the morphogenic development of insects. Despite the availability of genome sequences from several insect species and the extensive knowledge of certain signalling pathways that underpin ecdysteroidogenesis, the spectrum of signalling molecules and ecdysteroidogenic cascades is still not fully comprehensive. To fill this gap and obtain the complete list of cell membrane receptors expressed in PG cells, we used combinatory bioinformatic, proteomic and transcriptomic analysis and quantitative PCR to annotate and determine the expression profiles of genes identified as putative cell membrane receptors of the model insect species, Bombyx mori, and subsequently enrich the repertoire of signalling pathways that are present in its PG cells. The genome annotation dataset we report here highlights modules and pathways that may be directly involved in ecdysteroidogenesis and aims to disseminate data and assist other researchers in the discovery of the role of such receptors and their ligands. PMID:27576083

  16. Combinatory annotation of cell membrane receptors and signalling pathways of Bombyx mori prothoracic glands

    PubMed Central

    Moulos, Panagiotis; Samiotaki, Martina; Panayotou, George; Dedos, Skarlatos G.

    2016-01-01

    The cells of prothoracic glands (PG) are the main site of synthesis and secretion of ecdysteroids, the biochemical products of cholesterol conversion to steroids that shape the morphogenic development of insects. Despite the availability of genome sequences from several insect species and the extensive knowledge of certain signalling pathways that underpin ecdysteroidogenesis, the spectrum of signalling molecules and ecdysteroidogenic cascades is still not fully comprehensive. To fill this gap and obtain the complete list of cell membrane receptors expressed in PG cells, we used combinatory bioinformatic, proteomic and transcriptomic analysis and quantitative PCR to annotate and determine the expression profiles of genes identified as putative cell membrane receptors of the model insect species, Bombyx mori, and subsequently enrich the repertoire of signalling pathways that are present in its PG cells. The genome annotation dataset we report here highlights modules and pathways that may be directly involved in ecdysteroidogenesis and aims to disseminate data and assist other researchers in the discovery of the role of such receptors and their ligands. PMID:27576083

  17. Efficient silkworm expression of human GPCR (nociceptin receptor) by a Bombyx mori bacmid DNA system

    SciTech Connect

    Kajikawa, Mizuho; Sasaki, Kaori; Wakimoto, Yoshitaro; Toyooka, Masaru; Motohashi, Tomoko; Shimojima, Tsukasa; Takeda, Shigeki; Park, Enoch Y.; Maenaka, Katsumi

    2009-07-31

    Guanine nucleotide-binding protein (G protein) coupled receptors (GPCRs) are frequently expressed by a baculovirus expression vector system (BEVS). We recently established a novel BEVS using the bacmid system of Bombyx mori nucleopolyhedrovirus (BmNPV), which is directly applicable for protein expression in silkworms. Here, we report the first example of GPCR expression in silkworms by the simple injection of BmNPV bacmid DNA. Human nociceptin receptor, an inhibitory GPCR, and its fusion protein with inhibitory G protein alpha subunit (G{sub i}{alpha}) were both successfully expressed in the fat bodies of silkworm larvae as well as in the BmNPV viral fraction. Its yield was much higher than that from Sf9 cells. The microsomal fractions including the nociceptin receptor fusion, which are easily prepared by only centrifugation steps, exhibited [{sup 35}S]GTP{gamma}S-binding activity upon specific stimulation by nociceptin. Therefore, this rapid method is easy-to-use and has a high expression level, and thus will be an important tool for human GPCR production.

  18. Identification of Bombyx mori midgut receptor for Bacillus thuringiensis insecticidal CryIA(a) toxin.

    PubMed

    Nagamatsu, Y; Toda, S; Yamaguchi, F; Ogo, M; Kogure, M; Nakamura, M; Shibata, Y; Katsumoto, T

    1998-04-01

    As part of a study of the mechanism by which Bacillus thuringiensis insecticidal crystal protein acts, a Bombyx mori receptor to the CryIA(a) toxin specific for lepidopterans was examined. Histological examination showed that the toxin acted on the brush-border membrane of the midgut columnar cells and broke its infolding structure, causing cell lysis. The membrane vesicles were purified, and a 175-kDa protein binding the toxin was found that accounted for some 0.015% of membrane proteins. The protein, designated BtR175, was a glycoprotein that reacted with concanavalin A. Anti-BtR antibodies inhibited the binding of toxin to membrane vesicles in vitro and decreased the effect of the toxin to silkworms in vivo. BtR175, although found in the gut, was not found in fat bodies, integument, or silk glands. These results indicated that BtR175 was the receptor protein for the insecticidal toxin. Proteins (137 and 107 kDa) binding the CryIA(a) toxin also were found in the gut membranes of Tenebrio moritor larvae, a coleopteran not sensitive to the toxin. The specificity of the toxin could not be explained only in term of the existence of its binding protein. PMID:9614702

  19. Understanding CELSRs - Cadherin EGF LAG seven-pass G-type receptors

    PubMed Central

    Wang, Xiao-Jing; Zhang, Dao-Lai; Xu, Zhi-Gang; Ma, Ming-Liang; Wang, Wen-Bo; Li, Lin-Lin; Han, Xiao-Lin; Huo, Yuqing; Yu, Xiao; Sun, Jin-Peng

    2014-01-01

    The cadherin EGF LAG seven-pass G-type receptors (CELSRs) are a special subgroup of adhesion G protein-coupled receptors (GPCRs), which are pivotal regulators of many biological processes such as neuronal/endocrine cell differentiation, vessel valve formation and the control of planar cell polarity during embryonic development. All three members of the CELSR family (CELSR1-3) have large ecto-domains that form homophilic interactions and encompass more than 2,000 amino acids. Mutations in the ecto-domain or other gene locations of CELSRs are associated with neural tube defects (NTDs) and other diseases in humans. Celsr knockout (KO) animals have many developmental defects. Therefore, specific agonists or antagonists of CELSR members may have therapeutic potential. Although significant progress has been made regarding the functions and biochemical properties of CELSRs, our knowledge of these receptors is still lacking, especially considering that they are broadly distributed but have few characterized functions in a limited number of tissues. The dynamic activation and inactivation of CELSRs and the presence of endogenous ligands beyond homophilic interactions remain elusive, as do the regulatory mechanisms and downstream signaling of these receptors. Given this motivation, future studies with more advanced cell biology or biochemical tools, such as conditional KO mice, may provide further insights into the mechanisms underlying CELSR function, laying the foundation for the design of new CELSR-targeted therapeutic reagents. PMID:25280249

  20. Characterization of a ligand-gated cation channel based on an inositol receptor in the silkworm, Bombyx mori.

    PubMed

    Kikuta, Shingo; Endo, Haruka; Tomita, Natsuo; Takada, Tomoyuki; Morita, Chiharu; Asaoka, Kiyoshi; Sato, Ryoichi

    2016-07-01

    Insect herbivores recognize non-volatile compounds in plants to direct their feeding behavior. Gustatory receptors (Gr) appear to be required for nutrient recognition by gustatory organs in the mouthparts of insects. Gr10 is expressed in Bombyx mori (BmGr10) mouthparts such as maxillary galea, maxillary palp, and labrum. BmGr10 is predicted to function in sugar recognition; however, the precise biochemical function remains obscure. Larvae of B. mori are monophagous feeders able to find and feed on mulberry leaves. Soluble mulberry leaf extract contains sucrose, glucose, fructose, and myo-inositol. In this study, we identified BmGr10 as an inositol receptor using electrophysiological analysis with the Xenopus oocyte expression system and Ca(2+) imaging techniques using mammalian cells. These results demonstrated that Xenopus oocytes or HEK293T cells expressing BmGr10 specifically respond to myo-inositol and epi-inositol but do not respond to any mono-, di-, or tri-saccharides or to some sugar alcohols. These inositols caused Ca(2+) and Na(+) influxes into the cytoplasm independently of a G protein-mediated signaling cascade, indicating that BmGr10 is a ligand-gated cation channel. Overall, BmGr10 plays an important role in the myo-inositol recognition required for B. mori larval feeding behavior. PMID:27132146

  1. Vitellogenin Receptor Mutation Leads to the Oogenesis Mutant Phenotype “scanty vitellin” of the Silkworm, Bombyx mori*

    PubMed Central

    Lin, Ying; Meng, Yan; Wang, Yan-Xia; Luo, Juan; Katsuma, Susumu; Yang, Cong-Wen; Banno, Yutaka; Kusakabe, Takahiro; Shimada, Toru; Xia, Qing-You

    2013-01-01

    In insects, the vitellogenin receptor (VgR) mediates the uptake of vitellogenin (Vg) from the hemolymph by developing oocytes. The oogenesis mutant scanty vitellin (vit) of Bombyx mori (Bm) lacks vitellin and 30-kDa proteins, but B. mori egg-specific protein and BmVg are normal. The vit eggs are white and smaller compared with the pale yellow eggs of the wild type and are embryonic lethal. This study found that a mutation in the B. mori VgR gene (BmVgR) is responsible for the vit phenotype. We cloned the cDNA sequences encoding WT and vit BmVgR. The functional domains of BmVgR are similar to those of other low-density lipoprotein receptors. When compared with the wild type, a 235-bp genomic sequence in vit BmVgR is substituted for a 7-bp sequence. This mutation has resulted in a 50-amino acid deletion in the third Class B region of the first epidermal growth factor (EGF1) domain. BmVgR is expressed specifically in oocytes, and the transcriptional level is changed dramatically and consistently with maturation of oocytes during the previtellogenic periods. Linkage analysis confirmed that BmVgR is mutated in the vit mutant. The coimmunoprecipitation assay confirmed that mutated BmVgR is able to bind BmVg but that BmVg cannot be dissociated under acidic conditions. The WT phenotype determined by RNA interference was similar to that of the vit phenotype for nutritional deficiency, such as BmVg and 30-kDa proteins. These results showed that BmVgR has an important role in transporting proteins for egg formation and embryonic development in B. mori. PMID:23515308

  2. Identification of specific sites in the third intracellular loop and carboxyl terminus of the Bombyx mori PBAN receptor crucial for ligand-induced internalization

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Sex pheromone production in most moths is mediated by the pheromone biosynthesis activating neuropeptide receptor (PBANR). Similar to other rhodopsin-like G protein-coupled receptors, the silkmoth Bombyx mori PBANR (BmPBANR) undergoes agonist-induced internalization. Despite interest in developing...

  3. Epidermal Growth Factor Receptor Mutation Enhances Expression of Cadherin-5 in Lung Cancer Cells

    PubMed Central

    Hung, Ming-Szu; Chen, I-Chuan; Lung, Jr-Hau; Lin, Paul-Yann; Li, Ya-Chin; Tsai, Ying-Huang

    2016-01-01

    Epidermal growth factor receptor (EGFR) activation has been shown to play a critical role in tumor angiogenesis. In this study, we investigate the correlation between EGFR mutations and cadherin-5 (CDH5), which is an angiogenic factor, in lung cancer cells. Increased expression CDH5 is observed in lung cancer cells with EGFR mutations. Stable lung cancer cell lines expressing mutant (exon 19 deletion E746-A750, and exon 21 missense mutation L858R) and wild type EGFR genes are established. A significantly higher expression of CDH5 is observed in exon 19 deletion stable lung cancer cells and mouse xenografts. Further studies show that expression of CDH5 is decreased after the inhibition of EGFR and downstream Akt pathways in lung cancer cells with EGFR mutation. In addition, mutant EGFR genes potentiates angiogenesis in lung cancer cells, which is inhibited by CDH5 siRNA, and potentiates migration and invasion in lung cancer cells. Our study shows that mutant EGFR genes are associated with overexpression of CDH5 through increased phosphorylation of EGFR and downstream Akt pathways. Our result may provide an insight into the association of mutant EGFR and CDH5 expression in lung cancer and aid further development of target therapy for NSCLC in the future. PMID:27362942

  4. Expression of functional human (pro)renin receptor in silkworm (Bombyx mori) larvae using BmMNPV bacmid.

    PubMed

    Du, Dongning; Kato, Tatsuya; Nabi, A H M Nurun; Suzuki, Fumiaki; Park, Enoch Y

    2008-03-01

    The circulating RA (renin-angiotensin) system is essential for the regulation of blood pressure and electrolyte balance. Recently, plasma prorenin has been reported to significantly increase its level in diabetes and to be possibly non-proteolytically activated by binding to the PRR [(pro)renin receptor] on the cell membrane reported in several tissues during circulation. Although many pathological aspects have been researched, there is a lack of sufficient information on the biochemical structure and biological function of this hPRR (human PRR) because of the difficulty in increasing hPRR expression. In the present study, GFP(uv)-hPRR (hPRR fused with green fluorescence protein when excited with long-wave UV light) was successfully expressed by using BmMNPV (Bombyx mori multiple nucleopolyhedrovirus) bacmid DNA in silkworm (Bombyx mori) larvae. Some of the hPRR was expressed in the haemolymph of silkworm larvae and some of the hPRR was located in the fat body of silkworm larvae. The binding ability of hPRR expressed in the haemolymph and fat body with renin or prorenin was analysed by ELISA and surface plasmon resonance using a biosensor respectively. These binding assays suggest that the expressed hPRR has a functional bioactivity. hPRR preparation in silkworm larvae would, therefore, be useful for biochemical and biomedical researches related to PRR. PMID:17705788

  5. Agonist-mediated activation of Bombyx mori diapause hormone receptor signals to extracellular signal-regulated kinases 1 and 2 through Gq-PLC-PKC-dependent cascade.

    PubMed

    Jiang, Xue; Yang, Jingwen; Shen, Zhangfei; Chen, Yajie; Shi, Liangen; Zhou, Naiming

    2016-08-01

    Diapause is a developmental strategy adopted by insects to survive in challenging environments such as the low temperatures of a winter. This unique process is regulated by diapause hormone (DH), which is a neuropeptide hormone that induces egg diapause in Bombyx mori and is involved in terminating pupal diapause in heliothis moths. An G protein-coupled receptor from the silkworm, B. mori, has been identified as a specific cell surface receptor for DH. However, the detailed information on the DH-DHR system and its mechanism(s) involved in the induction of embryonic diapause remains unknown. Here, we combined functional assays with various specific inhibitors to elucidate the DHR-mediated signaling pathways. Upon activation by DH, B. mori DHR is coupled to the Gq protein, leading to a significant increase of intracellular Ca(2+) and cAMP response element-driven luciferase activity in an UBO-QIC, a specific Gq inhibitor, sensitive manner. B. mori DHR elicited ERK1/2 phosphorylation in a dose- and time-dependent manner in response to DH. This effect was almost completely inhibited by co-incubation with UBO-QIC and was also significantly suppressed by PLC inhibitor U73122, PKC inhibitors Gö6983 and the Ca(2+) chelator EGTA. Moreover, DHR-induced activation of ERK1/2 was significantly attenuated by treatment with the Gβγ specific inhibitors gallein and M119K and the PI3K specific inhibitor Wortmannin, but not by the Src specific inhibitor PP2. Our data also demonstrates that the EGFR-transactivation pathway is not involved in the DHR-mediated ERK1/2 phosphorylation. Future efforts are needed to clarify the role of the ERK1/2 signaling pathway in the DH-mediated induction of B. mori embryonic diapause. PMID:27318251

  6. Phosphatidylinositol 5-phosphate 4-kinase type II beta is required for vitamin D receptor-dependent E-cadherin expression in SW480 cells

    SciTech Connect

    Kouchi, Zen; Fujiwara, Yuki; Yamaguchi, Hideki; Nakamura, Yoshikazu; Fukami, Kiyoko

    2011-05-20

    Highlights: {yields} We analyzed Phosphatidylinositol 5-phosphate kinase II{beta} (PIPKII{beta}) function in cancer. {yields} PIPKII{beta} is required for vitamin D receptor-mediated E-cadherin upregulation in SW480. {yields} PIPKII{beta} suppresses cellular motility through E-cadherin induction in SW480 cells. {yields} Nuclear PIP{sub 2} but not plasma membrane-localized PIP{sub 2} mediates E-cadherin upregulation. -- Abstract: Numerous epidemiological data indicate that vitamin D receptor (VDR) signaling induced by its ligand or active metabolite 1{alpha},25-dihydroxyvitamin D{sub 3} (1{alpha},25(OH){sub 2}D{sub 3}) has anti-cancer activity in several colon cancers. 1{alpha},25(OH){sub 2}D{sub 3} induces the epithelial differentiation of SW480 colon cancer cells expressing VDR (SW480-ADH) by upregulating E-cadherin expression; however, its precise mechanism remains unknown. We found that phosphatidylinositol-5-phosphate 4-kinase type II beta (PIPKII{beta}) but not PIPKII{alpha} is required for VDR-mediated E-cadherin induction in SW480-ADH cells. The syntenin-2 postsynaptic density protein/disc large/zona occludens (PDZ) domain and pleckstrin homology domain of phospholipase C-delta1 (PLC{delta}1 PHD) possess high affinity for phosphatidylinositol-4,5-bisphosphate (PI(4,5)P{sub 2}) mainly localized to the nucleus and plasma membrane, respectively. The expression of syntenin-2 PDZ but not PLC{delta}1 PHD inhibited 1{alpha},25(OH){sub 2}D{sub 3}-induced E-cadherin upregulation, suggesting that nuclear PI(4,5)P{sub 2} production mediates E-cadherin expression through PIPKII{beta} in a VDR-dependent manner. PIPKII{beta} is also involved in the suppression of the cell motility induced by 1{alpha},25(OH){sub 2}D{sub 3}. These results indicate that PIPKII{beta}-mediated PI(4,5)P{sub 2} signaling is important for E-cadherin upregulation and inhibition of cellular motility induced by VDR activation.

  7. Endothelial tyrosine kinase receptor B prevents VE-cadherin cleavage and protects against atherosclerotic lesion development in ApoE−/− mice

    PubMed Central

    Jiang, Hong; Huang, Shuhong; Li, Xinyun; Li, Xian; Huang, Shanying; Zhang, Yun; Chen, Zhe-Yu

    2015-01-01

    Tyrosine kinase receptor B (TrkB) is a high-affinity receptor for brain-derived neurotrophic factor (BDNF). In addition to its nervous system functions, TrkB is also expressed in the aortic endothelium. However, the effects of endothelial TrkB signaling on atherosclerosis remained unknown. Immunofluorescence analysis revealed that TrkB expression is downregulated in the endothelium of atherosclerotic lesions from ApoE−/− mice compared with the atheroma-free aorta of WT mice. Endothelial TrkB knockdown led to increased lesion size, lipid deposition and inflammatory responses in the atherosclerotic lesions of the ApoE−/− mice compared with the control mice. Mechanistic studies showed that TrkB activation prevented VE-cadherin shedding by enhancing the interaction between vascular endothelial protein tyrosine phosphatase and VE-cadherin, maintaining VE-cadherin in a dephosphorylated state. Our data demonstrate that TrkB is an endothelial injury-response molecule in atherogenesis. Endothelial BDNF/TrkB signaling reduces VE-cadherin shedding and protects against atherosclerotic lesion development in ApoE−/− mice. PMID:26431274

  8. Female-biased expression of odourant receptor genes in the adult antennae of the silkworm, Bombyx mori.

    PubMed

    Wanner, K W; Anderson, A R; Trowell, S C; Theilmann, D A; Robertson, H M; Newcomb, R D

    2007-02-01

    Olfaction plays an important role in the life history of insects, including key behaviours such as host selection, oviposition and mate recognition. Odour perception by insects is primarily mediated by the large diverse family of odourant receptors (Ors) that are expressed on the dendrites of olfactory neurones housed within chemosensilla. However, few Or sequences have been identified from the Lepidoptera, an insect order that includes some of the most important pest species worldwide. We have identified 41 Or gene sequences from the silkworm (Bombyx mori) genome, more than double the number of published Or sequences from the Lepidoptera. Many silkworm Ors appear to be orthologs of the 17 published tobacco budworm (Heliothis virescens) Ors indicating that many Or lineages may be conserved within the Lepidoptera. The majority of the Or genes are expressed in adult female and male antennae (determined by quantitative real-time PCR analysis), supporting their probable roles in adult olfaction. Several Or genes are expressed at high levels in both male and female antennae, suggesting they mediate the perception of common host or conspecific volatiles important to both sexes. BmOrs 45-47 group together in the same phylogenetic branch and all three are expressed at moderate female-biased ratios, six to eight times higher in female compared to male moth antennae. Interestingly, BmOrs19 and 30 appear to be expressed predominantly in female antennae, opposite to that of the published silkworm pheromone receptors BmOrs 1 and 3 that are specific to male antennae. These results suggest that BmOr19 and 30 may detect odours critical to female behaviour, such as oviposition cues or male-produced courtship pheromones. PMID:17257213

  9. Tachykinin-Related Peptides Share a G Protein-Coupled Receptor with Ion Transport Peptide-Like in the Silkworm Bombyx mori

    PubMed Central

    Nagai-Okatani, Chiaki; Nagasawa, Hiromichi

    2016-01-01

    Recently, we identified an orphan Bombyx mori neuropeptide G protein-coupled receptor (BNGR)-A24 as an ion transport peptide-like (ITPL) receptor. BNGR-A24 belongs to the same clade as BNGR-A32 and -A33, which were recently identified as natalisin receptors. Since these three BNGRs share high similarities with known receptors for tachykinin-related peptides (TRPs), we examined whether these BNGRs can function as physiological receptors for five endogenous B. mori TRPs (TK-1–5). In a heterologous expression system, BNGR-A24 acted as a receptor for all five TRPs. In contrast, BNGR-A32 responded only to TK-5, and BNGR-A33 did not respond to any of the TRPs. These findings are consistent with recent studies on the ligand preferences for B. mori natalisins. Furthermore, we evaluated whether the binding of ITPL and TRPs to BNGR-A24 is competitive by using a Ca2+ imaging assay. Concomitant addition of a TRP receptor antagonist, spantide I, reduced the responses of BNGR-A24 not only to TK-4 but also to ITPL. The results of a binding assay using fluorescent-labeled BNGR-A24 and ligands demonstrated that the binding of ITPL to BNGR-A24 was inhibited by TK-4 as well as by spantide I, and vice versa. In addition, the ITPL-induced increase in cGMP levels of BNGR-A24-expressing BmN cells was suppressed by the addition of excess TK-4 or spantide I. The intracellular levels of cAMP and cGMP, as second messenger candidates of the TRP signaling, were not altered by the five TRPs, suggesting that these peptides act via different signaling pathways from cAMP and cGMP signaling at least in BmN cells. Taken together, the present findings suggest that ITPL and TRPs are endogenous orthosteric ligands of BNGR-A24 that may activate discrete signaling pathways. This receptor, which shares orthosteric ligands, may constitute an important model for studying ligand-biased signaling. PMID:27248837

  10. Tachykinin-Related Peptides Share a G Protein-Coupled Receptor with Ion Transport Peptide-Like in the Silkworm Bombyx mori.

    PubMed

    Nagai-Okatani, Chiaki; Nagasawa, Hiromichi; Nagata, Shinji

    2016-01-01

    Recently, we identified an orphan Bombyx mori neuropeptide G protein-coupled receptor (BNGR)-A24 as an ion transport peptide-like (ITPL) receptor. BNGR-A24 belongs to the same clade as BNGR-A32 and -A33, which were recently identified as natalisin receptors. Since these three BNGRs share high similarities with known receptors for tachykinin-related peptides (TRPs), we examined whether these BNGRs can function as physiological receptors for five endogenous B. mori TRPs (TK-1-5). In a heterologous expression system, BNGR-A24 acted as a receptor for all five TRPs. In contrast, BNGR-A32 responded only to TK-5, and BNGR-A33 did not respond to any of the TRPs. These findings are consistent with recent studies on the ligand preferences for B. mori natalisins. Furthermore, we evaluated whether the binding of ITPL and TRPs to BNGR-A24 is competitive by using a Ca2+ imaging assay. Concomitant addition of a TRP receptor antagonist, spantide I, reduced the responses of BNGR-A24 not only to TK-4 but also to ITPL. The results of a binding assay using fluorescent-labeled BNGR-A24 and ligands demonstrated that the binding of ITPL to BNGR-A24 was inhibited by TK-4 as well as by spantide I, and vice versa. In addition, the ITPL-induced increase in cGMP levels of BNGR-A24-expressing BmN cells was suppressed by the addition of excess TK-4 or spantide I. The intracellular levels of cAMP and cGMP, as second messenger candidates of the TRP signaling, were not altered by the five TRPs, suggesting that these peptides act via different signaling pathways from cAMP and cGMP signaling at least in BmN cells. Taken together, the present findings suggest that ITPL and TRPs are endogenous orthosteric ligands of BNGR-A24 that may activate discrete signaling pathways. This receptor, which shares orthosteric ligands, may constitute an important model for studying ligand-biased signaling. PMID:27248837

  11. Effects of Starvation on Brain Short Neuropeptide F-1, -2, and -3 Levels and Short Neuropeptide F Receptor Expression Levels of the Silkworm, Bombyx mori

    PubMed Central

    Nagata, Shinji; Matsumoto, Sumihiro; Nakane, Tomohiro; Ohara, Ayako; Morooka, Nobukatsu; Konuma, Takahiro; Nagai, Chiaki; Nagasawa, Hiromichi

    2012-01-01

    In our previous report, we demonstrated the possibility that various regulatory neuropeptides influence feeding behavior in the silkworm, Bombyx mori. Among these feeding-related neuropeptides, short neuropeptide F (sNPF) exhibited feeding-accelerating activity when injected into B. mori larvae. Like other insect sNPFs, the deduced amino acid sequence of the cDNA encoding the sNPF precursor appears to produce multiple sNPF and sNPF-related peptides in B. mori. The presence of three sNPFs, sNPF-1, sNPF-2, and sNPF-3, in the brain of B. mori larvae was confirmed by direct MALDI-TOF mass spectrometric profiling. In addition, all three sNPFs are present in other larval ganglia. The presence of sNPF mRNA in the central nervous system (CNS) was also confirmed by Reverse transcription-polymerase chain reaction. Semi-quantitative analyses of sNPFs in the larval brain using matrix-assisted laser desorption ionization time-of-flight mass spectrometry further revealed that brain sNPF levels decrease in response to starvation, and that they recover with the resumption of feeding. These data suggest that sNPFs were depleted by the starvation process. Furthermore, food deprivation decreased the transcriptional levels of the sNPF receptor (BNGR-A10) in the brain and CNS, suggesting that the sNPF system is dependent on the feeding state of the insect and that the sNPF system may be linked to locomotor activity associated with foraging behavior. Since the injection of sNPFs accelerated the onset of feeding in B. mori larvae, we concluded that sNPFs are strongly related to feeding behavior. In addition, semi-quantitative MS analyses revealed that allatostatin, which is present in the larval brain, is also reduced in response to starvation, whereas the peptide level of Bommyosuppressin was not affected by different feeding states. PMID:22649403

  12. MicroRNA-281 regulates the expression of ecdysone receptor (EcR) isoform B in the silkworm, Bombyx mori

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Hundreds of Bombyx mori miRNAs had been identified in recent years, but their function in vivo remains poorly understood. The silkworm EcR gene (BmEcR) has three transcriptional isoforms, A, B1 and B2. Isoform sequences are different in the 3’UTR region of the gene, which is the case only in insects...

  13. Bombyx mori prothoracicostatic peptide receptor is allosterically activated via a Gα(i/o)-protein-biased signalling cascade by Drosophila sex peptide.

    PubMed

    He, Xiaobai; Zang, Jiashu; Yang, Huipeng; Huang, Haishan; Shi, Ying; Zhu, Chenggang; Zhou, Naiming

    2015-03-01

    In insects, molting and metamorphosis are strictly regulated by ecdysteroids. Ecdysteroid synthesis is positively or negatively controlled by several neuropeptides. The prothoracicostatic peptide (PTSP) BmPTSP (Bombyx mori prothoracicostatic peptide), isolated from the larval brain of B. mori, has been demonstrated to inhibit ecdysteroid synthesis in the prothoracic glands (PGs) [Hua et al. (1999) J. Biol. Chem. 274, 31169-31173]. More recently, the newly recognized B. mori receptor for Drosophila melanogaster sex peptide (DmSP) has been identified as a receptor for BmPTSP. However, details on the signalling pathways and physiological functions of this receptor have remained elusive. In the present paper, we report the functional characterization of the BmPTSP receptor (BmPTSPR)/sex peptide (SP) receptor (SPR) using both mammalian and insect cells. Synthetic DmSP shows the potential to inhibit forskolin (FSK) or adipokinetic hormone (AKH)-induced cAMP-response element (CRE)-driven luciferase (Luc) activity in a manner comparable with synthetic BmPTSP1. However, DmSP displayed a much lower activity in triggering Ca²⁺ mobilization and internalization than did BmPTSP1. Additionally, 6-carboxy-fluorescein fluorophore (FAM)-labelled DmSP and BmPTSP3 were found to bind specifically to BmPTSPR/SPR. The binding of FAM-DmSP was displaced by unlabelled DmSP, but not by unlabelled BmPTSP1 and, vice versa, the binding of FAM-BmPTSP3 was blocked by unlabelled BmPTSP3, but not by unlabelled DmSP. Moreover, internalization assays demonstrated that BmPTSP1, but not DmSP, evoked recruitment of the Bombyx non-visual arrestin, Kurtz, to the activated BmPTSPR/SPR in the plasma membrane. This was followed by induction of internalization. This suggests that BmPTSP1 is probably an endogenous ligand specific for BmPTSPR/SPR. We therefore designate this receptor BmPTSPR. In contrast, DmSP is an allosteric agonist that is biased towards Gα(i/o)-dependent cAMP production and away from Ca

  14. Nuclear Signaling from Cadherin Adhesion Complexes

    PubMed Central

    McCrea, Pierre D.; Maher, Meghan T.; Gottardi, Cara J.

    2015-01-01

    The arrival of multicellularity in evolution facilitated cell–cell signaling in conjunction with adhesion. As the ectodomains of cadherins interact with each other directly in trans (as well as in cis), spanning the plasma membrane and associating with multiple other entities, cadherins enable the transduction of “outside-in” or “inside-out” signals. We focus this review on signals that originate from the larger family of cadherins that are inwardly directed to the nucleus, and thus have roles in gene control or nuclear structure–function. The nature of cadherin complexes varies considerably depending on the type of cadherin and its context, and we will address some of these variables for classical cadherins versus other family members. Substantial but still fragmentary progress has been made in understanding the signaling mediators used by varied cadherin complexes to coordinate the state of cell–cell adhesion with gene expression. Evidence that cadherin intracellular binding partners also localize to the nucleus is a major point of interest. In some models, catenins show reduced binding to cadherin cytoplasmic tails favoring their engagement in gene control. When bound, cadherins may serve as stoichiometric competitors of nuclear signals. Cadherins also directly or indirectly affect numerous signaling pathways (e.g., Wnt, receptor tyrosine kinase, Hippo, NFκB, and JAK/STAT), enabling cell–cell contacts to touch upon multiple biological outcomes in embryonic development and tissue homeostasis. PMID:25733140

  15. Nuclear signaling from cadherin adhesion complexes.

    PubMed

    McCrea, Pierre D; Maher, Meghan T; Gottardi, Cara J

    2015-01-01

    The arrival of multicellularity in evolution facilitated cell-cell signaling in conjunction with adhesion. As the ectodomains of cadherins interact with each other directly in trans (as well as in cis), spanning the plasma membrane and associating with multiple other entities, cadherins enable the transduction of "outside-in" or "inside-out" signals. We focus this review on signals that originate from the larger family of cadherins that are inwardly directed to the nucleus, and thus have roles in gene control or nuclear structure-function. The nature of cadherin complexes varies considerably depending on the type of cadherin and its context, and we will address some of these variables for classical cadherins versus other family members. Substantial but still fragmentary progress has been made in understanding the signaling mediators used by varied cadherin complexes to coordinate the state of cell-cell adhesion with gene expression. Evidence that cadherin intracellular binding partners also localize to the nucleus is a major point of interest. In some models, catenins show reduced binding to cadherin cytoplasmic tails favoring their engagement in gene control. When bound, cadherins may serve as stoichiometric competitors of nuclear signals. Cadherins also directly or indirectly affect numerous signaling pathways (e.g., Wnt, receptor tyrosine kinase, Hippo, NFκB, and JAK/STAT), enabling cell-cell contacts to touch upon multiple biological outcomes in embryonic development and tissue homeostasis. PMID:25733140

  16. Expression of a sugar clade gustatory receptor, BmGr6, in the oral sensory organs, midgut, and central nervous system of larvae of the silkworm Bombyx mori.

    PubMed

    Mang, Dingze; Shu, Min; Endo, Haruka; Yoshizawa, Yasutaka; Nagata, Shinji; Kikuta, Shingo; Sato, Ryoichi

    2016-03-01

    Insects taste nonvolatile chemicals through gustatory receptors (Grs) and make choices for feeding, mating, and oviposition. To date, genome projects have identified 69 Gr genes in the silkworm, Bombyx mori; however, the expression sites of these Grs remain to be explored. In this study, we used reverse transcription (RT)-PCR to investigate expression of the B. mori Gr-6 (BmGr6) gene, a member of the putative sugar clade gene family in various tissues. BmGr6 is expressed in the midgut, central nervous system (CNS), and oral sensory organs. Moreover, immunohistochemistry using an anti-BmGr6 antiserum demonstrated that BmGr6 is expressed in cells by oral sensory organs, midgut and nervous system. Furthermore, double-immunohistochemistry indicated that BmGr6 is expressed in midgut enteroendocrine cells, also in CNS neurosecretory cells. In particular, a portion of BmGr6-expressing cells, in both midgut and CNS, secretes FMRFamide-related peptides (FaRPs). These results suggest that BmGr6 functions not only as a taste receptor, but also as a chemical sensor such as for the regulation of gut movement, physiological conditions, and feeding behavior of larvae. PMID:26721200

  17. Functional validation of cadherin as a receptor of Bt toxin Cry1Ac in Helicoverpa armigera utilizing the CRISPR/Cas9 system.

    PubMed

    Wang, Jing; Zhang, Haonan; Wang, Huidong; Zhao, Shan; Zuo, Yayun; Yang, Yihua; Wu, Yidong

    2016-09-01

    Cadherins have been identified as receptors of Bacillus thuringiensis (Bt) Cry1A toxins in several lepidopteran insects including the cotton bollworm, Helicoverpa armigera. Disruption of the cadherin gene HaCad has been genetically linked to resistance to Bt toxin Cry1Ac in H. armigera. By using the CRISPR/Cas9 genome editing system (Clustered Regularly Interspaced Short Palindromic Repeats/CRISPR-associated protein 9), HaCad from the Cry1Ac-susceptible SCD strain of H. armigera was successfully knocked out. A single positive CRISPR event with a frame shift deletion of 4 nucleotides was identified and made homozygous to create a knockout line named SCD-Cad. Western blotting confirmed that HaCad was no longer expressed in the SCD-Cad line while an intact HaCad of 210 kDa was present in the parental SCD strain. Insecticide bioassays were used to show that SCD-Cad exhibited 549-fold resistance to Cry1Ac compared with SCD, but no significant change in susceptibility to Cry2Ab. Our results not only provide strong reverse genetics evidence for HaCad as a functional receptor of Cry1Ac, but also demonstrate that the CRISPR/Cas9 technique can act as a powerful and efficient genome editing tool to study gene function in a global agricultural pest, H. armigera. PMID:27343383

  18. Hyaluronan suppresses prostate tumor cell proliferation through diminished expression of N-cadherin and aberrant growth factor receptor signaling

    SciTech Connect

    Bharadwaj, Alamelu G.; Goodrich, Nathaniel P.; McAtee, Caitlin O.; Haferbier, Katie; Oakley, Gregory G.; Wahl, James K.; Simpson, Melanie A.

    2011-05-01

    Hyaluronan (HA) production has been functionally implicated in prostate tumorigenesis and metastasis. We previously used prostate tumor cells overexpressing the HA synthesizing enzyme HAS3 or the clinically relevant hyaluronidase Hyal1 to show that excess HA production suppresses tumor growth, while HA turnover accelerates spontaneous metastasis from the prostate. Here, we examined pathways responsible for effects of HAS3 and Hyal1 on tumor cell phenotype. Detailed characterization of cell cycle progression revealed that expression of Hyal1 accelerated cell cycle re-entry following synchronization, whereas HAS3 alone delayed entry. Hyal1 expressing cells exhibited a significant reduction in their ability to sustain ERK phosphorylation upon stimulation by growth factors, and in their expression of the cyclin-dependent kinase inhibitor p21. In contrast, HAS3 expressing cells showed prolonged ERK phosphorylation and increased expression of both p21 and p27, in asynchronous and synchronized cultures. Changes in cell cycle regulatory proteins were accompanied by HA-induced suppression of N-cadherin, while E-cadherin expression and {beta}-catenin expression and distribution remained unchanged. Our results are consistent with a model in which excess HA synthesis suppresses cell proliferation by promoting homotypic E-cadherin mediated cell-cell adhesion, consequently signaling to elevate cell cycle inhibitor expression and suppress G1- to S-phase transition.

  19. Gene cloning and expression of cadherin in midgut of Helicoverpa armigera and its Cry1A binding region.

    PubMed

    Wang, Guirong; Wu, Kongming; Liang, Gemei; Guo, Yuyuan

    2005-08-01

    Cadherins belong to one of the families of animal glycoproteins responsible for calcium-dependent cell-cell adhesion. Recent literatures showed that the cadherin-like in midgut of several insects served as the receptor of Bt toxin Cry1A and the variation of cadherin-like is related to insect's resistance to Cry1A. The full-length cDNA encoding cadherin-like of Helicoverpa armigera is cloned by degenerate PCR and RACE techniques and the gene was designated as BtR-harm, which is 5581 bp in full-length, encoding 1730 amino acid residues (BtR-harm was deposited in GenBank and the accession number is AF519180). Its predicted molecular weight and isoelectric point were 195.39 kDa and 4.23, respectively. The inferred amino acid sequence includes a signal sequence, 11 cadherin repeats, a membrane-proximal region, a transmembrane region and a cytoplasmic region. Sequence analysis indicated that the deduced protein sequence was most similar to the cadherin-like from Heliothis virescens with 84.2% identity and highly similar to three other lepidopteran cadherin from Bombyx mori, Manduca sexta and Pectinophora gossypiella, with the sequence identities of 60.3.6%, 57.5% and 51.0%, respectively. The cDNA encoding cadherin gene was expressed successfully in E. coli and the recombinant proteins can bind with Cry1Ac. Truncation analysis and binding experiment of BtR-harm revealed that the Cry1A binding region was a contiguous 244-amino acid sequence, which located between amino acid 1217 and 1461. Semi-quantitative RT-PCR analysis showed that BtR-harm was highly expressed in midgut of H. armigera, very low expressed in foregut and hindgut and was not expressed in other tissues. After H. armigera producing resistance to Cry1Ac, the expression quantity of BtR-harm significantly decreased in midgut of H. armigera. It is the first confirmation that BtR-harm can function as receptor of Cry1Ac in H. armigera and the binding region was located on a contiguous 244 amino acid sequence

  20. Identification of specific sites in the third intracellular loop and carboxyl terminus of the Bombyx mori pheromone biosynthesis activating neuropeptide receptor crucial for ligand-induced internalization.

    PubMed

    Hull, J J; Lee, J M; Matsumoto, S

    2011-12-01

    Sex pheromone production in most moths is mediated by the pheromone biosynthesis activating neuropeptide receptor (PBANR). Using fluorescent Bombyx mori PBANR (BmPBANR) chimeras to study PBANR regulation, we previously showed that BmPBANR undergoes rapid ligand-induced internalization, that the endocytotic motif resides between residues 358-367 of the BmPBANR C terminus, and that the internalization pathway is clathrin-dependent. Here, we sought to expand our understanding of the molecular mechanisms underlying BmPBANR function and regulation by transiently expressing a series of fluorescent BmPBANR chimeric constructs in cultured Spodoptera frugiperda (Sf9) cells and assaying for internalization of a fluorescently labelled ligand. Pharmacological inhibition of phospholipase C significantly reduced internalization, suggesting that BmPBANR regulation proceeds via a conventional G-protein-dependent pathway. This was further supported by impaired internalization following site-directed mutagenesis of R263 and R264, two basic residues at the transmembrane 6 intracellular junction that are thought to stabilize G-protein coupling via electrostatic interactions. Ala substitution of S333 and S366, two consensus protein kinase C sites in the C terminus, likewise impaired internalization, as did RNA interference-mediated knockdown of Sf9 protein kinase C. N-terminal truncations of BmPBANR indicate that the first 27 residues are not necessary for cell surface trafficking or receptor functionality. PMID:21955122

  1. Stimulation of orphan nuclear receptor HR38 gene expression by PTTH in prothoracic glands of the silkworm, Bombyx mori.

    PubMed

    Gu, Shi-Hong; Hsieh, Yun-Chih; Lin, Pei-Ling

    2016-07-01

    A complex signaling network appears to be involved in prothoracicotropic hormone (PTTH)-stimulated ecdysteroidogenesis in insect prothoracic glands (PGs). Less is known about the genomic action of PTTH signaling. In the present study, we investigated the effect of PTTH on the expression of Bombyx mori HR38, an immediate early gene (IEG) identified in insect systems. Our results showed that treatment of B. mori PGs with PTTH in vitro resulted in a rapid increase in HR38 expression. Injection of PTTH into day-5 last instar larvae also greatly increased HR38 expression, verifying the in vitro effect. Cycloheximide did not affect induction of HR38 expression, suggesting that protein synthesis is not required for PTTH's effect. A mitogen-activated protein kinase (MAPK)/extracellular signal-regulated kinase (ERK) kinase (MEK) inhibitor (U0126), and a phosphoinositide 3-kinase (PI3K) inhibitor (LY294002), partially inhibited PTTH-stimulated HR38 expression, implying the involvement of both the ERK and PI3K signaling pathways. When PGs were treated with agents that directly elevate the intracellular Ca(2+) concentration (either A23187 or thapsigargin), an increase in HR38 expression was also detected, indicating that Ca(2+) is involved in PTTH-stimulated HR38 gene expression. A Western blot analysis showed that PTTH treatment increased the HR38 protein level, and protein levels showed a dramatic increase during the later stages of the last larval instar. Expression of HR38 transcription in response to PTTH appeared to undergo development-specific changes. Treatment with ecdysone in vitro did not affect HR38 expression. However, 20-hydroxyecdysone treatment decreased HR38 expression. Taken together, these results demonstrate that HR38 is a PTTH-stimulated IEG that is, at least in part, induced through Ca(2+)/ERK and PI3K signaling. The present study proposes a potential cross talk mechanism between PTTH and ecdysone signaling to regulate insect development and lays a

  2. E-cadherin expression on human carcinoma cell affects trastuzumab-mediated antibody-dependent cellular cytotoxicity through killer cell lectin-like receptor G1 on natural killer cells.

    PubMed

    Yamauchi, Chisako; Fujii, Satoshi; Kimura, Taichi; Kuwata, Takeshi; Wada, Noriaki; Mukai, Hirofumi; Matsumoto, Naoki; Fukayama, Masashi; Ochiai, Atsushi

    2011-05-01

    Trastuzumab is a recombinant antibody drug that is widely used for the treatment of HER2-overexpressing breast carcinoma. Despite encouraging clinical results, many HER2-overexpressing carcinomas are primarily resistant to trastuzumab. We attempted to explain trastuzumab resistance and search for solutions. Since the killer cell lectin-like receptor G1 (KLRG1), an inhibitory receptor expressed on subsets of natural killer (NK) cells recognizes E-cadherin as ligands and may inhibit immune responses by regulating the effector function of NK cells, we used HER2-overexpressing carcinoma cells which were expressing E-cadherin to investigate the role of antibody-dependent cellular cytotoxicity (ADCC) through KLRG1 on NK cells in vitro and vivo. The results indicated that HER2-overexpressing carcinoma cells were killed by trastuzumab-mediated ADCC and the ADCC activity was reflected the degree of E-cadherin expression on carcinoma cells. We found that expression of E-cadherin was shown to be a predictor of response to trastuzumab-based treatment for HER2-overexpressing carcinomas, furthermore, trastuzumab-mediated ADCC was markedly enhanced by KLRG1-negative peripheral blood mononuclear cells (PBMCs(KLRG1(-))). PMID:21387286

  3. Resistance of Trichoplusia ni to Bacillus thuringiensis Toxin Cry1Ac Is Independent of Alteration of the Cadherin-Like Receptor for Cry Toxins

    PubMed Central

    Zhang, Xin; Tiewsiri, Kasorn; Kain, Wendy; Huang, Lihua; Wang, Ping

    2012-01-01

    Alteration of binding sites for Bacillus thuringiensis (Bt) toxins in insect midgut is the major mechanism of high-level resistance to Bt toxins in insects. The midgut cadherin is known to be a major binding protein for Bt Cry1A toxins and linkage of Bt-resistance to cadherin gene mutations has been identified in lepidopterans. The resistance to Bt toxin Cry1Ac evolved in greenhouse populations of Trichoplusia ni has been identified to be associated with the down-regulation of an aminopeptidase N (APN1) gene by a trans-regulatory mechanism and the resistance gene has been mapped to the locus of an ABC transporter (ABCC2) gene. However, whether cadherin is also involved with Cry1Ac-resistance in T. ni requires to be understood. Here we report that the Cry1Ac-resistance in T. ni is independent of alteration of the cadherin. The T. ni cadherin cDNA was cloned and the cadherin sequence showed characteristic features known to cadherins from Lepidoptera. Various T. ni cadherin gene alleles were identified and genetic linkage analysis of the cadherin alleles with Cry1Ac-resistance showed no association of the cadherin gene with the Cry1Ac-resistance in T. ni. Analysis of cadherin transcripts showed no quantitative difference between the susceptible and Cry1Ac-resistant T. ni larvae. Quantitative proteomic analysis of midgut BBMV proteins by iTRAQ-2D-LC-MS/MS determined that there was no quantitative difference in cadherin content between the susceptible and the resistant larvae and the cadherin only accounted for 0.0014% (mol%) of the midgut BBMV proteins, which is 1/300 of APN1 in molar ratio. The cadherin from both the susceptible and resistant larvae showed as a 200-kDa Cry1Ac-binding protein by toxin overlay binding analysis, and nano-LC-MS/MS analysis of the 200-kDa cadherin determined that there is no quantitative difference between the susceptible and resistant larvae. Results from this study indicate that the Cry1Ac-resistance in T. ni is independent of cadherin

  4. Resistance of Trichoplusia ni to Bacillus thuringiensis toxin Cry1Ac is independent of alteration of the cadherin-like receptor for Cry toxins.

    PubMed

    Zhang, Xin; Tiewsiri, Kasorn; Kain, Wendy; Huang, Lihua; Wang, Ping

    2012-01-01

    Alteration of binding sites for Bacillus thuringiensis (Bt) toxins in insect midgut is the major mechanism of high-level resistance to Bt toxins in insects. The midgut cadherin is known to be a major binding protein for Bt Cry1A toxins and linkage of Bt-resistance to cadherin gene mutations has been identified in lepidopterans. The resistance to Bt toxin Cry1Ac evolved in greenhouse populations of Trichoplusia ni has been identified to be associated with the down-regulation of an aminopeptidase N (APN1) gene by a trans-regulatory mechanism and the resistance gene has been mapped to the locus of an ABC transporter (ABCC2) gene. However, whether cadherin is also involved with Cry1Ac-resistance in T. ni requires to be understood. Here we report that the Cry1Ac-resistance in T. ni is independent of alteration of the cadherin. The T. ni cadherin cDNA was cloned and the cadherin sequence showed characteristic features known to cadherins from Lepidoptera. Various T. ni cadherin gene alleles were identified and genetic linkage analysis of the cadherin alleles with Cry1Ac-resistance showed no association of the cadherin gene with the Cry1Ac-resistance in T. ni. Analysis of cadherin transcripts showed no quantitative difference between the susceptible and Cry1Ac-resistant T. ni larvae. Quantitative proteomic analysis of midgut BBMV proteins by iTRAQ-2D-LC-MS/MS determined that there was no quantitative difference in cadherin content between the susceptible and the resistant larvae and the cadherin only accounted for 0.0014% (mol%) of the midgut BBMV proteins, which is 1/300 of APN1 in molar ratio. The cadherin from both the susceptible and resistant larvae showed as a 200-kDa Cry1Ac-binding protein by toxin overlay binding analysis, and nano-LC-MS/MS analysis of the 200-kDa cadherin determined that there is no quantitative difference between the susceptible and resistant larvae. Results from this study indicate that the Cry1Ac-resistance in T. ni is independent of cadherin

  5. The Heliothis virescens cadherin protein expressed in Drosophila S2 cells functions as a receptor for Bacillus thuringiensis Cry1A but not Cry1Fa toxins.

    PubMed

    Jurat-Fuentes, Juan Luis; Adang, Michael J

    2006-08-15

    Genetic knockout of the BtR4 gene encoding the Heliothis virescens cadherin-like protein (HevCaLP) is linked to resistance against Cry1Ac toxin from Bacillus thuringiensis. However, the functional Cry1Ac receptor role of this protein has not been established. We previously proposed HevCaLP as a shared binding site for B. thuringiensis (Bt) Cry1A and Cry1Fa toxins in the midgut epithelium of H. virescens larvae. Considering that Cry1Ac and Cry1Fa are coexpressed in second-generation transgenic cotton for enhanced control of Heliothine and Spodoptera species, our model suggests the possibility of evolution of cross resistance via alteration of HevCaLP. To test whether HevCaLP is a Cry1Ac and Cry1Fa receptor, HevCaLP was transiently expressed on the surface of Drosophila melanogaster Schneider 2 (S2) cells. Expressed HevCaLP bound [(125)I]Cry1A toxins under native (dot blot) and denaturing (ligand blot) conditions. Affinity pull-down assays demonstrated that Cry1Fa does not bind to HevCaLP expressed in S2 cells or in solubilized brush border membrane proteins. Using a fluorescence-based approach, we tested the ability of expressed HevCaLP to mediate toxicity of Cry1A and Cry1Fa toxins. Cry1A toxins killed S2 cells expressing HevCaLP, whereas Cry1Fa toxin did not. Our results demonstrate that HevCaLP is a functional Cry1A but not Cry1Fa receptor. PMID:16893170

  6. Cadherin-5: a biomarker for metastatic breast cancer with optimum efficacy in oestrogen receptor-positive breast cancers with vascular invasion

    PubMed Central

    Fry, Simon A; Robertson, Claire E; Swann, Ruth; Dwek, Miriam V

    2016-01-01

    Background: A glycoproteomic study has previously shown cadherin-5 (CDH5) to be a serological marker of metastatic breast cancer when both protein levels and glycosylation status were assessed. In this study we aimed to further validate the utility of CDH5 as a biomarker for breast cancer progression. Methods: A nested case–control study of serum samples from breast cancer patients, of which n=52 had developed a distant metastatic recurrence within 5 years post-diagnosis and n=60 had remained recurrence-free. ELISAs were used to quantify patient serum CDH5 levels and assess glycosylation by Helix pomatia agglutinin (HPA) binding. Clinicopathological, treatment and lifestyle factors associated with metastasis and elevated biomarker levels were identified. Results: Elevated CDH5 levels (P=0.028) and ratios of CDH5:HPA binding (P=0.007) distinguished patients with metastatic disease from those that remained metastasis-free. Multivariate analysis showed that the association between CDH5:HPA ratio and the formation of distant metastases was driven by patients with oestrogen receptor (ER+) positive cancer with vascular invasion (VI+). Conclusions: CDH5 levels and the CDH5 glycosylation represent biomarker tests that distinguish patients with metastatic breast cancer from those that remain metastasis-free. The test reached optimal sensitivity and specificity in ER-positive cancers with vascular invasion. PMID:27010749

  7. The Arginine Residue within the C-Terminal Active Core of Bombyx mori Pheromone Biosynthesis-Activating Neuropeptide is Essential for Receptor Binding and Activation

    PubMed Central

    Kawai, Takeshi; Lee, Jae Min; Nagata, Koji; Matsumoto, Shogo; Tanokura, Masaru; Nagasawa, Hiromichi

    2012-01-01

    In most lepidopteran insects, the biosynthesis of sex pheromones is regulated by pheromone biosynthesis-activating neuropeptide (PBAN). Bombyx mori PBAN (BomPBAN) consists of 33 amino acid residues and contains a C-terminus FSPRLamide motif as the active core. Among neuropeptides containing the FXPRLamide motif, the arginine (Arg, R) residue at the second position from the C-terminus is highly conserved across several neuropeptides, which can be designated as RXamide peptides. The purpose of this study was to clarify the role of the Arg residue in the BomPBAN active core. We synthesized 10-residue peptides corresponding to the C-terminal part of BomPBAN with a series of replacements at the second position from the C-terminus, termed the C2 position, and measured their efficacy in stimulating Ca2+ influx in insect cells expressing a fluorescent PBAN receptor chimera (PBANR–EGFP) using the fluorescent Ca2+ indicator, Fura Red–AM. The PBAN analogs with the C2 position replaced with alanine (Ala, A), aspartic acid (Asp, D), serine (Ser, S), or l-2-aminooctanoic acid (Aoc) decreased PBAN-like activity. RC2A (SKTRYFSPALamide) and RC2D (SKTRYFSPDLamide) had the lowest activity and could not inhibit the activity of PBAN C10 (SKTRYFSPRLamide). We also prepared Rhodamine Red-labeled peptides of the PBAN analogs and examined their ability to bind PBANR. In contrast to Rhodamine Red-PBAN C10 at 100 nM, none of the synthetic analogs exhibited PBANR binding at the same concentration. Taken together, our results demonstrate that the C2 Arg residue in BomPBAN is essential for PBANR binding and activation. PMID:22654866

  8. Intermittent expression of BmFTZ-F1, a member of the nuclear hormone receptor superfamily during development of the silkworm Bombyx mori.

    PubMed

    Sun, G C; Hirose, S; Ueda, H

    1994-04-01

    BmFTZ-F1 is a sequence-specific DNA-binding factor in the silkworm Bombyx mori sharing similar biochemical characteristics with Drosophila FTZ-F1, a member of the nuclear hormone receptor superfamily. Using DNA sequence homology with FTZ-F1 and information on tryptic peptide sequences of BmFTZ-F1, we isolated a cDNA encoding for BmFTZ-F1. Amino acid sequences in the zinc finger DNA-binding region and the putative ligand-binding domain of BmFTZ-F1 showed strong similarity to not only FTZ-F1 but also its mammalian homologues, LRH-1, ELP, and Ad4BP, suggesting the importance of each region for the function of these proteins. Northern blot analyses of RNA isolated from the middle and posterior silk glands and fat bodies showed that a 6.1-kb BmFTZ-F1 mRNA is present in all tissues so far examined. Expression of BmFTZ-F1 mRNA is intermittent, being high during larval molting and both the larval-pupal and the pupal-adult transformations. Injection of 20-hydroxyecdysone at the third day of the 5th instar larvae induced BmFTZ-F1 mRNA in the posterior silk gland after 24 hr. When 5th instar silk glands were cultured in vitro, BmFTZ-F1 mRNA was induced by a 6-hr exposure to 20-hydroxyecdysone followed by 6 hr in hormone-free medium. These results suggest that BmFTZ-F1 is inducible by decline in the ecdysteroid titer and may play an important role in the development of the silkworm as a transcription factor. PMID:8150206

  9. Cadherins in cancer.

    PubMed

    Strumane, K; Berx, G; Van Roy, F

    2004-01-01

    The presence of a functional E-cadherin/catenin cell-cell adhesion complex is a prerequisite for normal development and maintenance of epithelial structures in the mammalian body. This implies that the acquisition of molecular abnormalities that disturb the expression or function of this complex is related to the development and progression of most, if not all, epithelial cell-derived tumors, i.e. carcinomas. E-cadherin downregulation is indeed correlated with malignancy parameters such as tumor progression, loss of differentiation, invasion and metastasis, and hence poor prognosis. Moreover, E-cadherin has been shown to be a potent invasion suppressor as well as a tumor suppressor. Disturbed expression profiles of the E-cadherin/catenin complex have been demonstrated in histological sections of many human tumor types. In different kinds of carcinomas, biallelic downregulation of the E-cadherin gene, resulting in tumor-restricted decrease or even complete loss of E-cadherin expression, appears to be caused by a variety of inactivation mechanisms. Gene deletion due to loss of heterozygosity of the CDH1 locus on 16q22.1 frequently occurs in many carcinoma types. However, somatic inactivating mutations resulting in aberrant E-cadherin expression by loss of both wild-type alleles is rare and restricted to only a few cancer types. A majority of carcinomas thus seems to show deregulated E-cadherin expression by other mechanisms. The present evidence proposes transcriptional repression as a powerful and recurrent molecular mechanism for silencing E-cadherin expression. The predominant mechanisms emerging in most carcinomas are hypermethylation of the E-cadherin promoter and expression of transrepressor molecules such as SIP1, Snail, and Slug that bind sequence elements in the proximal E-cadherin promoter. Interestingly, complex differential expression of other cadherins seems to be associated with loss of E-cadherin and to reinforce effects of this loss on tumor

  10. Anomalous expression of P-cadherin in breast carcinoma. Correlation with E-cadherin expression and pathological features.

    PubMed Central

    Palacios, J.; Benito, N.; Pizarro, A.; Suárez, A.; Espada, J.; Cano, A.; Gamallo, C.

    1995-01-01

    Previous studies on the cell-cell adhesion molecules P- and E-cadherin have shown that P-cadherin is not expressed in breast cancer. In contrast, the expression of E-cadherin is a normal event in these tumors, but a reduction in the levels of this molecule in neoplastic cells is associated with the histological type, high histological grade, greater tumor size, and metastasis. The expression pattern of P- and E-cadherin were immunohistochemically studied in tissue sections from normal breast tissue, benign breast lesions, and 57 infiltrating breast carcinomas. Cadherin expression was analyzed in parallel with pathological features and the immunohistochemical expression of estrogen and progesterone receptors in breast carcinomas. P-cadherin was detected in the myoepithelial cells and E-cadherin in luminal epithelial cells from normal breast and benign breast lesions. P-cadherin expression was detected in 9 of 45 cases (20%) of infiltrating ductal carcinomas of no special type; none of the special histological types that were analyzed (7 infiltrating lobular carcinomas, 3 colloid carcinomas, and 2 infiltrating papillary carcinomas) expressed P-cadherin. In infiltrating ductal carcinomas, P-cadherin expression correlated significantly with a reduction in E-cadherin expression, histological grade (all cases were grade III tumors), and hormone receptor content (8 of 9 cases were estrogen and progesterone receptor negative). Although E-cadherin was not found in the 7 infiltrating lobular carcinomas, it was present in the remaining histological types and was preserved in 15 infiltrating ductal and 3 colloid and 2 papillary carcinomas and was reduced in 30 infiltrating ductal carcinomas. In addition, a reduction in E-cadherin expression was significantly associated with high histological grade and a lack of steroid hormone receptors in infiltrating ductal carcinomas. No apparent relationship was found between P- and E-cadherin expression and tumor size and axillary lymph

  11. Expression of the fructose receptor BmGr9 and its involvement in the promotion of feeding, suggested by its co-expression with neuropeptide F1 in Bombyx mori.

    PubMed

    Mang, Dingze; Shu, Min; Tanaka, Shiho; Nagata, Shinji; Takada, Tomoyuki; Endo, Haruka; Kikuta, Shingo; Tabunoki, Hiroko; Iwabuchi, Kikuo; Sato, Ryoichi

    2016-08-01

    Insect gustatory receptors (Grs) are members of a large family of proteins with seven transmembrane domains that provide insects with the ability to detect chemical signals critical for feeding, mating, and oviposition. To date, 69 Bombyx mori Grs (BmGrs) genes have been identified via genome studies. BmGr9 has been shown to respond specifically to fructose and to function as a ligand-gated ion channel selectively activated by fructose. However, the sites where this Gr are expressed remain unclear. We demonstrated using reverse transcription (RT)-PCR that BmGr9 is widely expressed in the central nervous system (CNS), as well as oral sensory organs. Additionally, immunohistochemistry was performed using anti-BmGr9 antiserum to show that BmGr9 is expressed in cells of the oral sensory organs, including the maxillary galea, maxillary palps, labrum, and labium, as well as in putative neurosecretory cells of the CNS. Furthermore, double immunohistochemical analysis showed that most BmGr9-expressing cells co-localized with putative neuropeptide F1-expressing cells in the brain, suggesting that BmGr9 is involved in the promotion of feeding behaviors. In addition, a portion of BmGr9-expressing cells in the brain co-localized with cells expressing BmGr6, a molecule of the sugar receptor clade, suggesting that sugars other than fructose are involved in the regulation of feeding behaviors in B. mori larvae. PMID:27288056

  12. Cadherin controls nectin recruitment into adherens junctions by remodeling the actin cytoskeleton

    PubMed Central

    Troyanovsky, Regina B.; Indra, Indrajyoti; Chen, Chi-Shuo; Hong, Soonjin; Troyanovsky, Sergey M.

    2015-01-01

    ABSTRACT The mechanism that coordinates activities of different adhesion receptors is poorly understood. We investigated this mechanism by focusing on the nectin-2 and E-cadherin adherens junction receptors. We found that, cadherin was not required for the basic process of nectin junction formation because nectin-2 formed junctions in cadherin-deficient A431D cells. Formation of nectin-2 junctions in these cells, however, became regulated by cadherin as soon as E-cadherin was re-expressed. E-cadherin recruited nectin-2 into adherens junctions, where both proteins formed distinct but tightly associated clusters. Live-cell imaging showed that the appearance of E-cadherin clusters often preceded that of nectin-2 clusters at sites of junction assembly. Inactivation of E-cadherin clustering by different strategies concomitantly suppressed the formation of nectin clusters. Furthermore, cadherin significantly increased the stability of nectin clusters, thereby making them resistant to the BC-12 antibody, which targets the nectin-2 adhesion interface. By testing different E-cadherin–α-catenin chimeras, we showed that the recruitment of nectin into chimera junctions is mediated by the actin-binding domain of α-catenin. Our data suggests that E-cadherin regulates assembly of nectin junctions through α-catenin-induced remodeling of the actin cytoskeleton around the cadherin clusters. PMID:25395582

  13. Cadherins: The Superfamily Critically Involved in Breast Cancer.

    PubMed

    Ashaie, Maeirah Afzal; Chowdhury, Ezharul Hoque

    2016-01-01

    Breast cancer, one of the leading causes of mortality and morbidity among females, is regulated in part by diverse classes of adhesion molecules one of which is known as cadherins. Located at adherens junctions, the members of this superfamily are responsible for upholding proper cell-cell adhesion. Cadherins possess diverse structures and functions and any alteration in their structures or functions causes impeding of normal mammary cells development and maintenance, thus leading to breast malignancy. E-, N-, P-, VE-, Proto-, desmosomal and FAT cadherins have been found to regulate breast cancer in positive as well as negative fashion, whereby both Ecadherin (CDH1) and N-cadherin (CDH2) contribute significantly towards transitioning from epithelial state to mesenchymal state (EMT) and enacting the abnormal cells to invade and metastasize nearby and distant tissues. Aberration in gene expression of cadherins can be either due to somatic or epigenetic silencing or via transcriptional factors. Besides other cadherins, E-cadherin which serves as hallmark of EMT is associated with several regulatory factors such as Snail, Slug, Twist, Zeb, KLF4, NFI, TBX2, SIX, b-Myb, COX-2, Arf6, FOXA2, GATA3 and SMAR1, which modulate E-cadherin gene transcription to promote or represses tumor invasion and colonization. Signaling molecules such as Notch, TGF-β, estrogen receptors, EGF and Wnt initiate numerous signaling cascades via these vital factors of cell programming, controlling expression of E-cadherin at transcriptional (mRNA) and protein level. Thus, interactions of cadherins with their roles in tumor suppression and oncogenic transformation can be beneficial in providing valuable insights for breast cancer diagnosis and therapeutics development. PMID:26825466

  14. Single amino acid insertions in extracellular loop 2 of Bombyx mori ABCC2 disrupt its receptor function for Bacillus thuringiensis Cry1Ab and Cry1Ac but not Cry1Aa toxins.

    PubMed

    Tanaka, Shiho; Miyamoto, Kazuhisa; Noda, Hiroaki; Endo, Haruka; Kikuta, Shingo; Sato, Ryoichi

    2016-04-01

    In a previous report, seven Cry1Ab-resistant strains were identified in the silkworm, Bombyx mori; these strains were shown to have a tyrosine insertion at position 234 in extracellular loop 2 of the ABC transporter C2 (BmABCC2). This insertion was confirmed to destroy the receptor function of BmABCC2 and confer the strains resistance against Cry1Ab and Cry1Ac. However, these strains were susceptible to Cry1Aa. In this report, we examined the mechanisms of the loss of receptor function of the transporter by expressing mutations in Sf9 cells. After replacement of one or two of the five amino acid residues in loop 2 of the susceptible BmABCC2 gene [BmABCC2_S] with alanine, cells still showed susceptibility, retaining the receptor function. Five mutants with single amino acid insertions at position 234 in BmABCC2 were also generated, resulting in loop 2 having six amino acids, which corresponds to replacing the tyrosine insertion in the resistant BmABCC2 gene [BmABCC2_R(+(234)Y)] with another amino acid. All five mutants exhibited loss of function against Cry1Ab and Cry1Ac. These results suggest that the amino acid sequence in loop 2 is less important than the loop size (five vs. six amino acids) or loop structure for Cry1Ab and Cry1Ac activity. Several domain-swapped mutant toxins were then generated among Cry1Aa, Cry1Ab, and Cry1Ac, which are composed of three domains. Swapped mutants containing domain II of Cry1Ab or Cry1Ac did not kill Sf9 cells expressing BmABCC2_R(+(234)Y), suggesting that domain II of the Cry toxin is related to the interaction with the receptor function of BmABCC2. This also suggests that different reactions against Bt-toxins in some B. mori strains, that is, Cry1Ab resistance or Cry1Aa susceptibility, are attributable to structural differences in domain II of Cry1A toxins. PMID:26928903

  15. Sequence variation and differential splicing of the midgut cadherin gene in Trichoplusia ni.

    PubMed

    Zhang, Xin; Kain, Wendy; Wang, Ping

    2013-08-01

    The insect midgut cadherin serves as an important receptor for the Cry toxins from Bacillus thuringiensis (Bt). Variation of the cadherin in insect populations provides a genetic potential for development of cadherin-based Bt resistance in insect populations. Sequence analysis of the cadherin from the cabbage looper, Trichoplusia ni, together with cadherins from 18 other lepidopterans showed a similar phylogenetic relationship of the cadherins to the phylogeny of Lepidoptera. The midgut cadherin in three laboratory populations of T. ni exhibited high variability, although the resistance to Bt toxin Cry1Ac in the T. ni strain is not genetically associated with cadherin gene mutations. A total of 142 single nucleotide polymorphisms (SNPs) were identified in the cadherin cDNAs from the T. ni strains, including 20 missense mutations. In addition, insertion and deletion polymorphisms (indels) were also identified in the cadherin alleles in T. ni. More interestingly, the results from this study reveal that differential splicing of mRNA also occurs in the cadherin gene expression. Therefore, variation of the midgut cadherin in insects may not only be caused by cadherin gene mutations, but could also result from alternative splicing of its mRNA regulated by factors acting in trans. Analysis of cadherin gene alleles in F2, F3 and F4 progenies from the cross between the Cry1Ac resistant and the susceptible strain after consecutive selections with Cry1Ac for three generations showed that selection with Cry1Ac did not result in an increase of frequencies of the cadherin alleles originated from the resistant strain. PMID:23743444

  16. Cadherin-11 localizes to focal adhesions and promotes cell–substrate adhesion

    PubMed Central

    Langhe, Rahul P.; Gudzenko, Tetyana; Bachmann, Michael; Becker, Sarah F.; Gonnermann, Carina; Winter, Claudia; Abbruzzese, Genevieve; Alfandari, Dominique; Kratzer, Marie-Claire; Franz, Clemens M.; Kashef, Jubin

    2016-01-01

    Cadherin receptors have a well-established role in cell–cell adhesion, cell polarization and differentiation. However, some cadherins also promote cell and tissue movement during embryonic development and tumour progression. In particular, cadherin-11 is upregulated during tumour and inflammatory cell invasion, but the mechanisms underlying cadherin-11 stimulated cell migration are still incompletely understood. Here, we show that cadherin-11 localizes to focal adhesions and promotes adhesion to fibronectin in Xenopus neural crest, a highly migratory embryonic cell population. Transfected cadherin-11 also localizes to focal adhesions in different mammalian cell lines, while endogenous cadherin-11 shows focal adhesion localization in primary human fibroblasts. In focal adhesions, cadherin-11 co-localizes with β1-integrin and paxillin and physically interacts with the fibronectin-binding proteoglycan syndecan-4. Adhesion to fibronectin mediated by cadherin-11/syndecan-4 complexes requires both the extracellular domain of syndecan-4, and the transmembrane and cytoplasmic domains of cadherin-11. These results reveal an unexpected role of a classical cadherin in cell–matrix adhesion during cell migration. PMID:26952325

  17. Important factors mediates the adhesion of aspergillus fumigatus to alveolar epithelial cells with E-cadherin

    PubMed Central

    Xu, Xiao-Yong; Chen, Fei; Sun, He; Chen, Chen; Zhao, Bei-Lei

    2016-01-01

    Aspergillus is widely distributed in the Earth’s biosphere. It has strong adaptive capacity, and lives as saprophytic or parasitic life. This study aims to investigate the role of E-cadherin for adhesion of Aspergillus fumigatus blastospores in a human epithelial cell line (A549) and search the correlated molecule in aspergillus. A. fumigatus blastospores were incubated with the total protein of A549 to investigate the binding of E-cadherin and blastospores followed by an affinity purification procedure. After establishing the adhesion model, the adhesion of A. fumigatus blastospores by A549 cells was evaluated by down-regulating E-cadherin of A549 cells with small interfering RNA (siRNA). FVB mice constructed with E-cadherin down-regulation were infected with aspergillus fumigatus. Preliminary exploration of E-cadherin interacting protein on the surface of aspergillus fumigates by immunoprecipitation and mass spectrometry analysis. E-cadherin was adhered to the surface of A. fumigatus blastospore. Adhesion of the blastospores was reduced by blocking or down-regulating E-cadherin in A549 cells. E-cadherin showed limited significance in the process of mice against aspergillus fumigates. Mass spectrometry (MS) analysis indicated the following proteins AFUA_8G07080, AfA24A6.130c, XP_747789 can bind to E-cadherin. In conclusion, E-cadherin is a receptor for adhesion of A. fumigatus blastospores in epithelial cells. This may open a new approach to treat this fungal infection. PMID:27347350

  18. Important factors mediates the adhesion of aspergillus fumigatus to alveolar epithelial cells with E-cadherin.

    PubMed

    Xu, Xiao-Yong; Chen, Fei; Sun, He; Chen, Chen; Zhao, Bei-Lei

    2016-01-01

    Aspergillus is widely distributed in the Earth's biosphere. It has strong adaptive capacity, and lives as saprophytic or parasitic life. This study aims to investigate the role of E-cadherin for adhesion of Aspergillus fumigatus blastospores in a human epithelial cell line (A549) and search the correlated molecule in aspergillus. A. fumigatus blastospores were incubated with the total protein of A549 to investigate the binding of E-cadherin and blastospores followed by an affinity purification procedure. After establishing the adhesion model, the adhesion of A. fumigatus blastospores by A549 cells was evaluated by down-regulating E-cadherin of A549 cells with small interfering RNA (siRNA). FVB mice constructed with E-cadherin down-regulation were infected with aspergillus fumigatus. Preliminary exploration of E-cadherin interacting protein on the surface of aspergillus fumigates by immunoprecipitation and mass spectrometry analysis. E-cadherin was adhered to the surface of A. fumigatus blastospore. Adhesion of the blastospores was reduced by blocking or down-regulating E-cadherin in A549 cells. E-cadherin showed limited significance in the process of mice against aspergillus fumigates. Mass spectrometry (MS) analysis indicated the following proteins AFUA_8G07080, AfA24A6.130c, XP_747789 can bind to E-cadherin. In conclusion, E-cadherin is a receptor for adhesion of A. fumigatus blastospores in epithelial cells. This may open a new approach to treat this fungal infection. PMID:27347350

  19. E-cadherin is important for cell differentiation during osteoclastogenesis.

    PubMed

    Fiorino, Cara; Harrison, Rene E

    2016-05-01

    E-cadherin, a protein responsible for intercellular adhesion between epithelial cells, is also expressed in the monocyte/macrophage lineage. In this study we have explored the involvement of E-cadherin during receptor activator of nuclear factor-κB ligand (RANKL)-stimulated osteoclast differentiation. Osteoclastogenesis involves a period of precursor expansion followed by multiple fusion events to generate a multinuclear osteoclast that is capable of bone resorption. We asked whether E-cadherin participated in early precursor interactions and recognition or was a component of the osteoclast fusion machinery. Here, we show that endogenous E-cadherin expression is the highest during early stages of osteoclast differentiation, with surface expression visible on small precursor cells (fewer than four nuclei per cell) in both RAW 264.7 cells and primary macrophages. Blocking E-cadherin function with neutralizing antibodies prior to the onset of fusion delayed the expression of TRAP, Cathepsin K, DC-STAMP and NFATc1 and significantly diminished multinucleated osteoclast formation. Conversely, E-cadherin-GFP overexpressing macrophages displayed earlier NFATc1 nuclear translocation along with faster formation of multinucleated osteoclasts compared to control macrophages. Through live imaging we identified that disrupting E-cadherin function prolonged the proliferative phase of the precursor population while concomitantly decreasing the proportion of migrating precursors. The lamellipodium and polarized membrane extensions appeared to be the principal sites of fusion, indicating precursor migration was a critical factor contributing to osteoclast fusion. These findings demonstrate that E-cadherin-mediated cell-cell contacts can modulate osteoclast-specific gene expression and prompt differentiating osteoclast precursors toward migratory and fusion activities. PMID:26959175

  20. E-cadherin Surface Levels in Epithelial Growth Factor-stimulated Cells Depend on Adherens Junction Protein Shrew-1

    PubMed Central

    Gross, Julia Christina; Schreiner, Alexander; Engels, Knut

    2009-01-01

    Gain- and loss-of-function studies indicate that the adherens junction protein shrew-1 acts as a novel modulator of E-cadherin internalization induced by epithelial growth factor (EGF) or E-cadherin function-blocking antibody during epithelial cell dynamics. Knocking down shrew-1 in MCF-7 carcinoma cells preserves E-cadherin surface levels upon EGF stimulation. Overexpression of shrew-1 leads to preformation of an E-cadherin/EGF receptor (EGFR) HER2/src-kinase/shrew-1 signaling complex and accelerated E-cadherin internalization. Shrew-1 is not sufficient to stimulate E-cadherin internalization, but facilitates the actions of EGFR and thus may promote malignant progression in breast cancer cells with constitutive EGFR stimulation by reducing surface E-cadherin expression. PMID:19515834

  1. Nucleation and growth of cadherin adhesions

    SciTech Connect

    Lambert, Mireille; Thoumine, Olivier; Brevier, Julien; Choquet, Daniel; Riveline, Daniel; Mege, Rene-Marc

    2007-11-15

    Cell-cell contact formation relies on the recruitment of cadherin molecules and their anchoring to actin. However, the precise chronology of events from initial cadherin trans-interactions to adhesion strengthening is unclear, in part due to the lack of access to the distribution of cadherins within adhesion zones. Using N-cadherin expressing cells interacting with N-cadherin coated surfaces, we characterized the formation of cadherin adhesions at the ventral cell surface. TIRF and RIC microscopies revealed streak-like accumulations of cadherin along actin fibers. FRAP analysis indicated that engaged cadherins display a slow turnover at equilibrium, compatible with a continuous addition and removal of cadherin molecules within the adhesive contact. Association of cadherin cytoplasmic tail to actin as well as actin cables and myosin II activity are required for the formation and maintenance of cadherin adhesions. Using time lapse microscopy we deciphered how cadherin adhesions form and grow. As lamellipodia protrude, cadherin foci stochastically formed a few microns away from the cell margin. Neo-formed foci coalesced aligned and coalesced with preformed foci either by rearward sliding or gap filling to form cadherin adhesions. Foci experienced collapse at the rear of cadherin adhesions. Based on these results, we present a model for the nucleation, directional growth and shrinkage of cadherin adhesions.

  2. Eshelby-Mori-Tanaka Approach

    Energy Science and Technology Software Center (ESTSC)

    2009-10-14

    EMTA is a stand-alone computer program that has been developed for the computation of elastic properties and thermal expansion coefficients (thermoelastic properties) of discontinuous fiber composites. EMTA stands for the Eshelby-Mori-Tanaka approach. It implements the standard and modified Mori-Tanaka models that use the Eshelby's equivalent inclusion method. EMTA carries out the Eshelby-Mori-Tanaka homogenization procedure accounting for the constituents (fiber and matrix) properties such as the elastic properties and thermal expansion coefficients (CTEs) of the fibersmore » and of the matrix. It also accounts for the constituents features such as fiber length and orientation distributions, fiber curvature, and imperfect fiber/matrix interfaces. The outputs of an EMTA execution are the elastic properties (engineering constants) and CTEs of the as-formed composite in the defined material coordinate system. These results can readily be used in engineering applications and designs that require these properties.« less

  3. Binding of phylogenetically distant Bacillus thuringiensis cry toxins to a Bombyx mori aminopeptidase N suggests importance of Cry toxin's conserved structure in receptor binding.

    PubMed

    Shinkawa, A; Yaoi, K; Kadotani, T; Imamura, M; Koizumi, N; Iwahana, H; Sato, R

    1999-07-01

    We investigated the binding proteins for three Cry toxins, Cry1Aa, Cry1Ac, and the phylogenetically distant Cry9Da, in the midgut cell membrane of the silkworm. In a ligand blot experiment, Cry1Ac and Cry9Da bound to the same 120-kDa aminopeptidase N (APN) as Cry1Aa. A competition experiment with the ligand blot indicated that the three toxins share the same binding site on several proteins. The values of the dissociation constants of the three Cry toxins and 120-kDa APN are as low as the case of other Cry toxins and receptors. These results suggest that distantly related Cry toxins bind to the same site on the same proteins, especially with APN. We propose that the conserved structure in these three toxins includes the receptor-binding site. PMID:10387111

  4. Reduction of Bacillus thuringiensis Cry1Ac Toxicity Against Helicoverpa armigera by a Soluble Toxin-Binding Cadherin Fragment

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A cadherin-like protein has been identified as a putative receptor for Bacillus thuringiensis (Bt) Cry1Ac toxin in Helicoverpa armigera and plays a key role in Bt insecticidal action. In this study, we produced a fragment from this H. armigera Cry1Ac toxin-binding cadherin that included the predict...

  5. Atypical cadherin negotiates a turn.

    PubMed

    Shi, Dongbo; Fujimori, Toshihiko; Uemura, Tadashi

    2013-07-15

    Planar cell polarity (PCP) signaling is involved in many polarized cell behaviors. In this issue of Developmental Cell, Tatin et al. (2013) show that the atypical cadherin Celsr1 is transiently localized to cellular protrusions in lymphatic endothelial cells and acts to orient valve-forming cells perpendicular to the vessel axis. PMID:23867224

  6. Structure and Binding Mechanism of Vascular Endothelial Cadherin: A Divergent Classical Cadherin

    SciTech Connect

    J Brasch; O Harrison; G Ahlsen; S Carnally; R Henderson; B Honig; L Shapiro

    2011-12-31

    Vascular endothelial cadherin (VE-cadherin), a divergent member of the type II classical cadherin family of cell adhesion proteins, mediates homophilic adhesion in the vascular endothelium. Previous investigations with a bacterially produced protein suggested that VE-cadherin forms cell surface trimers that bind between apposed cells to form hexamers. Here we report studies of mammalian-produced VE-cadherin ectodomains suggesting that, like other classical cadherins, VE-cadherin forms adhesive trans dimers between monomers located on opposing cell surfaces. Trimerization of the bacterially produced protein appears to be an artifact that arises from a lack of glycosylation. We also present the 2.1-{angstrom}-resolution crystal structure of the VE-cadherin EC1-2 adhesive region, which reveals homodimerization via the strand-swap mechanism common to classical cadherins. In common with type II cadherins, strand-swap binding involves two tryptophan anchor residues, but the adhesive interface resembles type I cadherins in that VE-cadherin does not form a large nonswapped hydrophobic surface. Thus, VE-cadherin is an outlier among classical cadherins, with characteristics of both type I and type II subfamilies.

  7. RPTPα controls epithelial adherens junctions, linking E-cadherin engagement to c-Src-mediated phosphorylation of cortactin.

    PubMed

    Truffi, Marta; Dubreuil, Véronique; Liang, Xuan; Vacaresse, Nathalie; Nigon, Fabienne; Han, Siew Ping; Yap, Alpha S; Gomez, Guillermo A; Sap, Jan

    2014-06-01

    Epithelial junctions are fundamental determinants of tissue organization, subject to regulation by tyrosine phosphorylation. Homophilic binding of E-cadherin activates tyrosine kinases, such as Src, that control junctional integrity. Protein tyrosine phosphatases (PTPs) also contribute to cadherin-based adhesion and signaling, but little is known about their specific identity or functions at epithelial junctions. Here, we report that the receptor PTP RPTPα (human gene name PTPRA) is recruited to epithelial adherens junctions at the time of cell-cell contact, where it is in molecular proximity to E-cadherin. RPTPα is required for appropriate cadherin-dependent adhesion and for cyst architecture in three-dimensional culture. Loss of RPTPα impairs adherens junction integrity, as manifested by defective E-cadherin accumulation and peri-junctional F-actin density. These effects correlate with a role for RPTPα in cellular (c)-Src activation at sites of E-cadherin engagement. Mechanistically, RPTPα is required for appropriate tyrosine phosphorylation of cortactin, a major Src substrate and a cytoskeletal actin organizer. Expression of a phosphomimetic cortactin mutant in RPTPα-depleted cells partially rescues F-actin and E-cadherin accumulation at intercellular contacts. These findings indicate that RPTPα controls cadherin-mediated signaling by linking homophilic E-cadherin engagement to cortactin tyrosine phosphorylation through c-Src. PMID:24652832

  8. N-cadherin expression is regulated by UTP in schwannoma cells.

    PubMed

    Martiáñez, Tania; Lamarca, Aloa; Casals, Nuria; Gella, Alejandro

    2013-06-01

    Schwann cells (SCs) are peripheral myelinating glial cells that express the neuronal Ca(2+)-dependent cell adhesion molecule, neural cadherin (N-cadherin). N-cadherin is involved in glia-glia and axon-glia interactions and participates in many key events, which range from the control of axonal growth and guidance to synapse formation and plasticity. Extracellular UTP activates P2Y purinergic receptors and exerts short- and long-term effects on several tissues to promote wound healing. Nevertheless, the contribution of P2Y receptors in peripheral nervous system functions is not completely understood. The current study demonstrated that UTP induced a dose- and time-dependent increase in N-cadherin expression in SCs. Furthermore, N-cadherin expression was blocked by the P2 purinoceptor antagonist suramin. The increased N-cadherin expression induced by UTP was mediated by phosphorylation of mitogen-activated protein kinases (MAPKs), such as Jun N-terminal kinase, extracellular-regulated kinase and p38 kinase. Moreover, the Rho kinase inhibitor Y27632, the phospholipase C inhibitor U73122 and the protein kinase C inhibitor calphostin C attenuated the UTP-induced activation of MAPKs significantly. Extracellular UTP also modulated increased in the expression of the early transcription factors c-Fos and c-Jun. We also demonstrated that the region of the N-cadherin promoter between nucleotide positions -3698 and -2620, which contained one activator protein-1-binding site, was necessary for UTP-induced gene expression. These results suggest a novel role for P2Y purinergic receptors in the regulation of N-cadherin expression in SCs. PMID:23271561

  9. Paranuaclear E-cadherin in gastric adenocarcinoma.

    PubMed

    Carpenter, Philip M; Al-Kuran, Rasha A; Theuer, Charles P

    2002-12-01

    Decreased E-cadherin expression permits dissociation and widespread dissemination of gastric adenocarcinoma cells. We studied the relationship between paranuclear E-cadherin distribution and the histopathologic characteristics of gastric adenocarcinomas. E-cadherin immunostains of 173 gastric adenocarcinoma sections revealed paranuclear; punctate to vesicular staining in 18% (16/87) of the intestinal-type adenocarcinomas, 30% (17/56) of the diffuse-type adenocarcinomas, and 30% (9/30) of the mired adenocarcinomas. These data suggest that in some gastric adenocarcinomas, there is a defect in transport of E-cadherin to the cell surface, which may prevent intercellular adhesion and encourage dissemination. Of 34 cancers with paranuclear E-cadherin staining, 20 (59%) had paranuclear staining within the nonneoplastic epithelium, but only 22.0% of 100 carcinomas with absent or membranous E-cadherin staining were accompanied by morphologically benign epithelium with paranuclear E-cadherin. In surface epithelium, paranuclear E-cadherin staining colocalized with Griffonia simplicifolia lectin II in the Golgi apparatus. The presence of paranuclear E-cadherin in cancer-associated benign epithelium suggests that the alteration in the E-cadherin molecule responsible for the paranuclear distribution may be an early change in gastric adenocarcinoma progression. PMID:12472282

  10. Design of a Photoswitchable Cadherin

    PubMed Central

    2013-01-01

    There is a growing interest in engineering proteins whose function can be controlled with the spatial and temporal precision of light. Here, we present a novel example of a functional light-triggered switch in the Ca-dependent cell–cell adhesion protein E-cadherin, created using a mechanism-based design strategy. We report an 18-fold change in apparent Ca2+ binding affinity upon illumination. Our results include a detailed examination of functional switching via linked changes in Ca2+ binding and cadherin dimerization. This design opens avenues toward controllable tools that could be applied to many long-standing questions about cadherin’s biological function in cell–cell adhesion and downstream signaling. PMID:23923816

  11. Adrenomedullin blockade induces regression of tumor neovessels through interference with vascular endothelial-cadherin signalling

    PubMed Central

    Fernandez-Sauze, Samantha; Berenguer-Daizé, Caroline; Sigaud, Romain; Delfino, Christine; Cayol, Mylène; Metellus, Philippe; Chinot, Olivier; Mabrouk, Kamel; Martin, Pierre-Marie; Ouafik, L'Houcine

    2015-01-01

    The cellular and molecular mechanisms by which adrenomedullin (AM) blockade suppresses tumor neovessels are not well defined. Herein, we show that AM blockade using anti-AM and anti-AM receptors antibodies targets vascular endothelial cells (ECs) and vascular smooth muscle cells (VSMCs), and induces regression of unstable nascent tumor neovessels. The underlying mechanism involved, and shown in vitro and in vivo in mice, is the disruption of the molecular engagement of the endothelial cell-specific junctional molecules vascular endothelial-cadherin (VE-cadherin)/β-catenin complex. AM blockade increases endothelial cell permeability by inhibiting cell-cell contacts predominantly through disruption of VE-cadherin/β-catenin/Akt signalling pathway, thereby leading to vascular collapse and regression of tumor neovessels. At a molecular level, we show that AM blockade induces tyrosine phosphorylation of VE-cadherin at a critical tyrosine, Tyr731, which is sufficient to prevent the binding of β-catenin to the cytoplasmic tail of VE-cadherin leading to the inhibition of cell barrier function. Furthermore, we demonstrate activation of Src kinase by phosphorylation on Tyr416, supporting a role of Src to phosphorylate Tyr731-VE-cadherin. In this model, Src inhibition impairs αAM and αAMR-induced Tyr731-VE-cadherin phosphorylation in a dose-dependent manner, indicating that Tyr731-VE-cadherin phosphorylation state is dependent on Src activation. We found that AM blockade induces β-catenin phosphorylation on Ser33/Ser37/Thr41 sites in both ECs and VSMCs both in vitro and in vivo in mice. These data suggest that AM blockade selectively induces regression of unstable tumor neovessels, through disruption of VE-cadherin signalling. Targeting AM system may present a novel therapeutic target to selectively disrupt assembly and induce regression of nascent tumor neovessels, without affecting normal stabilized vasculature. PMID:25924235

  12. Adrenomedullin blockade induces regression of tumor neovessels through interference with vascular endothelial-cadherin signalling.

    PubMed

    Khalfaoui-Bendriss, Ghizlane; Dussault, Nadège; Fernandez-Sauze, Samantha; Berenguer-Daizé, Caroline; Sigaud, Romain; Delfino, Christine; Cayol, Mylène; Metellus, Philippe; Chinot, Olivier; Mabrouk, Kamel; Martin, Pierre-Marie; Ouafik, L'Houcine

    2015-04-10

    The cellular and molecular mechanisms by which adrenomedullin (AM) blockade suppresses tumor neovessels are not well defined. Herein, we show that AM blockade using anti-AM and anti-AM receptors antibodies targets vascular endothelial cells (ECs) and vascular smooth muscle cells (VSMCs), and induces regression of unstable nascent tumor neovessels. The underlying mechanism involved, and shown in vitro and in vivo in mice, is the disruption of the molecular engagement of the endothelial cell-specific junctional molecules vascular endothelial-cadherin (VE-cadherin)/β-catenin complex. AM blockade increases endothelial cell permeability by inhibiting cell-cell contacts predominantly through disruption of VE-cadherin/β-catenin/Akt signalling pathway, thereby leading to vascular collapse and regression of tumor neovessels. At a molecular level, we show that AM blockade induces tyrosine phosphorylation of VE-cadherin at a critical tyrosine, Tyr731, which is sufficient to prevent the binding of β-catenin to the cytoplasmic tail of VE-cadherin leading to the inhibition of cell barrier function. Furthermore, we demonstrate activation of Src kinase by phosphorylation on Tyr416, supporting a role of Src to phosphorylate Tyr731-VE-cadherin. In this model, Src inhibition impairs αAM and αAMR-induced Tyr731-VE-cadherin phosphorylation in a dose-dependent manner, indicating that Tyr731-VE-cadherin phosphorylation state is dependent on Src activation. We found that AM blockade induces β-catenin phosphorylation on Ser33/Ser37/Thr41 sites in both ECs and VSMCs both in vitro and in vivo in mice. These data suggest that AM blockade selectively induces regression of unstable tumor neovessels, through disruption of VE-cadherin signalling. Targeting AM system may present a novel therapeutic target to selectively disrupt assembly and induce regression of nascent tumor neovessels, without affecting normal stabilized vasculature. PMID:25924235

  13. E-cadherin is required for intestinal morphogenesis in the mouse

    PubMed Central

    Bondow, Benjamin J.; Faber, Mary L.; Wojta, Kevin J.; Walker, Emily; Battle, Michele A.

    2012-01-01

    E-cadherin, the primary epithelial adherens junction protein, has been implicated as playing a critical role in nucleating formation of adherens junctions, tight junctions, and desmosomes. In addition to its role in maintaining structural tissue integrity, E-cadherin has also been suggested as an important modulator of cell signaling via interactions with its cytoplasmic binding partners, catenins, as well as with growth factor receptors. Therefore, we proposed that loss of E-cadherin from the developing mouse intestinal epithelium would disrupt intestinal epithelial morphogenesis and function. To test this hypothesis, we used a conditional knockout approach to eliminate E-cadherin specifically in the intestinal epithelium during embryonic development. We found that E-cadherin conditional knockout mice failed to survive, dying within the first 24 hours of birth. Examination of intestinal architecture at E18.5 demonstrated severe disruption to intestinal morphogenesis in animals lacking E-cadherin in the epithelium of the small intestine. We observed changes in epithelial cell shape as well as in the morphology of villi. Although junctional complexes were evident, junctions were abnormal, and barrier function was compromised in E-cadherin mutant intestine. We also identified changes in the epithelial cell populations present in E-cadherin conditional knockout animals. The number of proliferating cells was increased, whereas the number of enterocytes was decreased. Although Wnt/β-catenin target mRNAs were more abundant in mutants compared with controls, the amount of nuclear activated β-catenin protein was dramatically lower in mutants compared with controls. In summary, our data demonstrate that E-cadherin is essential for intestinal epithelial morphogenesis and homeostasis during embryonic development. PMID:22766025

  14. Mucinous Colorectal Adenocarcinoma: Influence of EGFR and E-Cadherin Expression on Clinicopathologic Features and Prognosis.

    PubMed

    Foda, Abd AlRahman M; AbdelAziz, Azza; El-Hawary, Amira K; Hosni, Ali; Zalata, Khalid R; Gado, Asmaa I

    2015-08-01

    Previous studies have shown conflicting results on epidermal growth factor receptor (EGFR) and E-cadherin expression in colorectal carcinoma and their prognostic significance. To the best of our knowledge, this study is the first to investigate EGFR and E-cadherin expression, interrelation and relation to clinicopathologic, histologic parameters, and survival in rare colorectal mucinous adenocarcinoma (MA). In this study, we studied tumor tissue specimens from 150 patients with colorectal MA and nonmucinous adenocarcinoma (NMA). High-density manual tissue microarrays were constructed using modified mechanical pencil tips technique, and immunohistochemistry for EGFR and E-cadherin was performed. All relations were analyzed using established statistical methodologies. NMA expressed EGFR and E-cadherin in significantly higher rates with significant heterogenous pattern than MA. EGFR and E-cadherin positivity rates were significantly interrelated in both NMA and MA groups. In the NMA group, high EGFR expression was associated with old age, male sex, multiplicity of tumors, lack of mucinous component, and association with schistosomiasis. However, in the MA group, high EGFR expression was associated only with old age and MA subtype rather than signet ring carcinoma subtype. Conversely, high E-cadherin expression in MA cases was associated with old age, fungating tumor configuration, MA subtype, and negative intratumoral lymphocytic response. However, in the NMA cases, none of these factors was statistically significant. In a univariate analysis, neither EGFR nor E-cadherin expression showed a significant impact on disease-free or overall survival. Targeted therapy against EGFR and E-cadherin may not be useful in patients with MA. Neither EGFR nor E-cadherin is an independent prognostic factor in NMA or MA. PMID:26262813

  15. Intestine-specific transcription factor Cdx2 induces E-cadherin function by enhancing the trafficking of E-cadherin to the cell membrane

    PubMed Central

    Funakoshi, Shinsuke; Kong, Jianping; Crissey, Mary Ann; Dang, Long; Dang, Duyen

    2010-01-01

    Cdx2 is an intestine-specific transcription factor required for normal intestinal epithelium development. Cdx2 regulates the expression of intestine-specific genes and induces cell adhesion and columnar morphogenesis. Cdx2 also has tumor-suppressor properties, including the reduction of colon cancer cell proliferation and cell invasion, the latter due to its effects on cell adhesion. E-cadherin is a cell adhesion protein required for adherens junction formation and the establishment of intestinal cell polarity. The objective of this study was to elucidate the mechanism by which Cdx2 regulates E-cadherin function. Two colon cancer cell lines were identified in which Cdx2 expression was associated with increased cell-cell adhesion and diminished cell migration. In both cell lines, Cdx2 did not directly alter E-cadherin levels but increased its trafficking to the cell membrane compartment. Cdx2 enhanced this trafficking by altering receptor tyrosine kinase (RTK) activity. Cdx2 expression diminished phosphorylated Abl and phosphorylated Rac levels, which are downstream effectors of RTKs. Specific chemical inhibition or short interfering RNA (shRNA) knockdown of c-Abl kinase phenocopied Cdx2's cell-cell adhesion effects. In Colo 205 cells, Cdx2 reduced PDGF receptor and IGF-I receptor activation. This was mediated by caveolin-1, which was induced by Cdx2. Targeted shRNA knockdown of caveolin-1 restored PDGF receptor and reversed E-cadherin membrane trafficking, despite Cdx2 expression. We conclude that Cdx2 regulates E-cadherin function indirectly by disrupting RTK activity and enhancing E-cadherin trafficking to the cell membrane compartment. This novel mechanism advances Cdx2's prodifferentiation and antitumor properties and suggests that Cdx2 may broadly regulate RTK activity in normal intestinal epithelium by modulating membrane trafficking of proteins. PMID:20671195

  16. Celsr1-3 cadherins in PCP and brain development.

    PubMed

    Boutin, Camille; Goffinet, André M; Tissir, Fadel

    2012-01-01

    Cadherin EGF LAG seven-pass G-type receptors 1, 2, and 3 (Celsr1-3) form a family of three atypical cadherins with multiple functions in epithelia and in the nervous system. During the past decade, evidence has accumulated for important and distinct roles of Celsr1-3 in planar cell polarity (PCP) and brain development and maintenance. Although the role of Celsr in PCP is conserved from flies to mammals, other functions may be more distantly related, with Celsr working only with one or a subset of the classical PCP partners. Here, we review the literature on Celsr in PCP and neural development, point to several remaining questions, and consider future challenges and possible research trends. PMID:23140629

  17. Cadherins as regulators of neuronal polarity

    PubMed Central

    Gärtner, Annette; Fornasiero, Eugenio F; Dotti, Carlos G

    2015-01-01

    A compelling amount of data is accumulating about the polyphonic role of neuronal cadherins during brain development throughout all developmental stages, starting from the involvement of cadherins in the organization of neurulation up to synapse development and plasticity. Recent work has confirmed that specifically N-cadherins play an important role in asymmetrical cellular processes in developing neurons that are at the basis of polarity. In this review we will summarize recent data, which demonstrate how N-cadherin orchestrates distinct processes of polarity establishment in neurons. PMID:25482615

  18. T-cadherin structures reveal a novel adhesive binding mechanism

    SciTech Connect

    Ciatto, Carlo; Bahna, Fabiana; Zampieri, Niccolò; VanSteenhouse, Harper C.; Katsamba, Phini S; Ahlsen, Goran; Harrison, Oliver J.; Brasch, Julia; Jin, Xiangshu; Posy, Shoshana; Vendome, Jeremie; Ranscht, Barbara; Jessell, Thomas M.; Honig, Barry; Shapiro, Lawrence

    2010-03-30

    Vertebrate genomes encode 19 classical cadherins and about 100 nonclassical cadherins. Adhesion by classical cadherins depends on binding interactions in their N-terminal EC1 domains, which swap N-terminal {beta}-strands between partner molecules from apposing cells. However, strand-swapping sequence signatures are absent from nonclassical cadherins, raising the question of how these proteins function in adhesion. Here, we show that T-cadherin, a glycosylphosphatidylinositol (GPI)-anchored cadherin, forms dimers through an alternative nonswapped interface near the EC1-EC2 calcium-binding sites. Mutations within this interface ablate the adhesive capacity of T-cadherin. These nonadhesive T-cadherin mutants also lose the ability to regulate neurite outgrowth from T-cadherin-expressing neurons. Our findings reveal the likely molecular architecture of the T-cadherin homophilic interface and its requirement for axon outgrowth regulation. The adhesive binding mode used by T-cadherin may also be used by other nonclassical cadherins

  19. Evidence of a common mechanism of disassembly of adherens junctions through Gα13 targeting of VE-cadherin

    PubMed Central

    Gong, Haixia; Gao, Xiaopei; Feng, Shaoting; Siddiqui, M. Rizwan; Garcia, Alexander; Bonini, Marcelo G.; Komarova, Yulia; Vogel, Stephen M.; Mehta, Dolly

    2014-01-01

    The heterotrimeric G protein Gα13 transduces signals from G protein–coupled receptors (GPCRs) to induce cell spreading, differentiation, migration, and cell polarity. Here, we describe a novel GPCR-independent function of Gα13 in regulating the stability of endothelial cell adherens junctions (AJs). We observed that the oxidant H2O2, which is released in response to multiple proinflammatory mediators, induced the interaction of Gα13 with VE-cadherin. Gα13 binding to VE-cadherin in turn induced Src activation and VE-cadherin phosphorylation at Tyr 658, the p120-catenin binding site thought to be responsible for VE-cadherin internalization. Inhibition of Gα13–VE-cadherin interaction using an interfering peptide derived from the Gα13 binding motif on VE-cadherin abrogated the disruption of AJs in response to inflammatory mediators. These studies identify a unique role of Gα13 binding to VE-cadherin in mediating VE-cadherin internalization and endothelial barrier disruption and inflammation. PMID:24590762

  20. The midgut cadherin-like gene is not associated with resistance to Bacillus thuringiensis toxin Cry1Ac in Plutella xylostella (L.).

    PubMed

    Guo, Zhaojiang; Kang, Shi; Zhu, Xun; Wu, Qingjun; Wang, Shaoli; Xie, Wen; Zhang, Youjun

    2015-03-01

    The Gram-positive bacterium Bacillus thuringiensis (Bt) produces Cry toxins that have been used to control important agricultural pests. Evolution of resistance in target pests threatens the effectiveness of these toxins when used either in sprayed biopesticides or in Bt transgenic crops. Although alterations of the midgut cadherin-like receptor can lead to Bt Cry toxin resistance in many insects, whether the cadherin gene is involved in Cry1Ac resistance of Plutella xylostella (L.) remains unclear. Here, we present experimental evidence that resistance to Cry1Ac or Bt var. kurstaki (Btk) in P. xylostella is not due to alterations of the cadherin gene. The bona fide P. xylostella cadherin cDNA sequence was cloned and analyzed, and comparisons of the cadherin cDNA sequence among susceptible and resistant P. xylostella strains confirmed that Cry1Ac resistance was independent of mutations in this gene. In addition, real-time quantitative PCR (qPCR) indicated that cadherin transcript levels did not significantly differ among susceptible and resistant P. xylostella strains. RNA interference (RNAi)-mediated suppression of cadherin gene expression did not affect larval susceptibility to Cry1Ac toxin. Furthermore, genetic linkage assays using four cadherin gDNA allelic biomarkers confirmed that the cadherin gene is not linked to resistance against Cry1Ac in P. xylostella. Taken together, our findings demonstrate that Cry1Ac resistance of P. xylostella is independent of the cadherin gene. PMID:25595643

  1. N-cadherin regulates molecular organization of excitatory and inhibitory synaptic circuits in adult hippocampus in vivo

    PubMed Central

    Nikitczuk, Jessica S.; Patil, Shekhar B.; Matikainen-Ankney, Bridget A.; Scarpa, Joseph; Shapiro, Matthew L.

    2016-01-01

    N-cadherin and β-catenin form a transsynaptic adhesion complex required for spine and synapse development. In adulthood, N-cadherin mediates persistent synaptic plasticity, but whether the role of N-cadherin at mature synapses is similar to that at developing synapses is unclear. To address this, we conditionally ablated N-cadherin from excitatory forebrain synapses in mice starting in late postnatal life and examined hippocampal structure and function in adulthood. In the absence of N-cadherin, β-catenin levels were reduced, but numbers of excitatory synapses were unchanged, and there was no impact on number or shape of dendrites or spines. However, the composition of synaptic molecules was altered. Levels of GluA1 and its scaffolding protein PSD95 were diminished and the density of immunolabeled puncta was decreased, without effects on other glutamate receptors and their scaffolding proteins. Additionally, loss of N-cadherin at excitatory synapses triggered increases in the density of markers for inhibitory synapses and decreased severity of hippocampal seizures. Finally, adult mutant mice were profoundly impaired in hippocampal-dependent memory for spatial episodes. These results demonstrate a novel function for the N-cadherin/β-catenin complex in regulating ionotropic receptor composition of excitatory synapses, an appropriate balance of excitatory and inhibitory synaptic proteins and the maintenance of neural circuitry necessary to generate flexible yet persistent cognitive and synaptic function. PMID:24753442

  2. Molecular Mechanics of Tip-Link Cadherins

    NASA Astrophysics Data System (ADS)

    Sotomayor, Marcos; Weihofen, Wilhelm A.; Gaudet, Rachelle; Corey, David P.

    2011-11-01

    The hair-cell tip link, a fine filament directly conveying force to mechanosensitive transduction channels, is likely composed of two proteins, protocadherin-15 and cadherin-23, whose mutation causes deafness. However, their complete molecular structure, elasticity, and deafness-related structural defects remain largely unknown. We present crystal structures of extracellular (EC) tip-link cadherin repeats involved in hereditary deafness and tip link formation. In addition, we show that the deafness mutation D101G, in the linker region between the repeats EC1 and EC2 of cadherin-23, causes a slight bend between repeats and decreases Ca2+ affinity. Molecular dynamics simulations suggest that tip-link cadherin repeats are stiff and that either removing Ca2+ or mutating Ca2+-binding residues reduces rigidity and unfolding strength. The structures and simulations also suggest mechanisms underlying inherited deafness and how cadherin-23 may bind with protocadherin-15 to form the tip link.

  3. Functional loss of E-cadherin and cadherin-11 alleles on chromosome 16q22 in colonic cancer.

    PubMed

    Braungart, E; Schumacher, C; Hartmann, E; Nekarda, H; Becker, K F; Höfler, H; Atkinson, M J

    1999-04-01

    Proteins of the cadherin family regulate cellular adhesion and motility and are believed to act as tumour suppressors. Previous studies have identified frequent mutation and allelic inactivation of the E-cadherin (cadherin-1) locus in diffuse gastric cancer. At least two other cadherin genes, P-cadherin (cadherin-3) and OB-cadherin (cadherin-11), have been mapped close to the E-cadherin gene on chromosome 16q22. As this region of the genome is frequently deleted in malignancy, multiple cadherin loci may be affected by losses of chromosome 16q22. The expression of mRNA transcripts from polymorphic alleles of the E-cadherin and cadherin-11 genes was examined in 30 cases of colonic, gastric, and renal carcinoma. In gastric cancer, loss of expression of one allele was restricted to the E-cadherin locus, whilst in renal carcinoma neither locus was affected. In colonic cancers, loss of expression of one E-cadherin allele was detected in 5 of 22 cases, whilst loss of a cadherin-11 allele was seen in 5 of 23 cases. This functional loss of cadherin gene expression may be due to gene deletion, inactivation or recombination. As no evidence of cadherin gene mutation was observed in the remaining transcripts, we can conclude that these two genes are only indirectly involved in the pathogenesis of colorectal cancer. PMID:10398117

  4. An ileal endometrioma: of carcinoids and cadherin.

    PubMed

    Pannala, Rahul; Gafni-Kane, Adam; Kidd, Mark; Modlin, Irvin M

    2007-02-01

    A 38-year-old woman with history of prior adrenalectomy for Cushing's syndrome presented with intermittent right lower quadrant (RLQ) abdominal pain, nausea, bloating, and non-bloody diarrhea for 2 months. Symptoms were not related to her menstrual periods. Examination revealed only an ill-defined mass in the RLQ. Investigations for infectious causes, inflammatory bowel disease, and carcinoid tumor were negative. Computed tomography (CT) demonstrated a terminal ileal mass with mesenteric stranding and dilatation of the proximal bowel. At laparotomy, a fibrotic, terminal ileal mass with matted adhesions involving the mesentery and retroperitoneum was resected. Histopathological examination identified multiple foci of endometriosis extending from the serosal surface into the mucosa of the terminal ileum. Immunostaining revealed E- and P-cadherin, but not N-cadherin immuno-positivity. Mucosal involvement without cyclical menstrual symptoms and intestinal obstruction is an unusual presentation of intestinal endometriosis. Although the mechanism of endometriosis is not clear, the role of cell adhesion molecules such as cadherins has received attention. Increased expression of E- and P-cadherin and decreased N-cadherin expression in our patient demonstrates differential expression of these cadherins in endometriotic tissue. Future studies may investigate patterns of differential expression of these cadherins in a series of cases to elucidate the mechanisms of migration of endometriotic tissue. PMID:17390177

  5. Vinculin potentiates E-cadherin mechanosensing and is recruited to actin-anchored sites within adherens junctions in a myosin II–dependent manner

    PubMed Central

    le Duc, Quint; Shi, Quanming; Blonk, Iris; Sonnenberg, Arnoud

    2010-01-01

    Cell surface receptors integrate chemical and mechanical cues to regulate a wide range of biological processes. Integrin complexes are the mechanotransducers between the extracellular matrix and the actomyosin cytoskeleton. By analogy, cadherin complexes may function as mechanosensors at cell–cell junctions, but this capacity of cadherins has not been directly demonstrated. Furthermore, the molecular composition of the link between E-cadherin and actin, which is needed to sustain such a function, is unresolved. In this study, we describe nanomechanical measurements demonstrating that E-cadherin complexes are functional mechanosensors that transmit force between F-actin and E-cadherin. Imaging experiments reveal that intercellular forces coincide with vinculin accumulation at actin-anchored cadherin adhesions, and nanomechanical measurements show that vinculin potentiates the E-cadherin mechanosensory response. These investigations directly demonstrate the mechanosensory capacity of the E-cadherin complex and identify a novel function for vinculin at cell–cell junctions. These findings have implications for barrier function, morphogenesis, cell migration, and invasion and may extend to all soft tissues in which classical cadherins regulate cell–cell adhesion. PMID:20584916

  6. E-cadherin Is Critical for Collective Sheet Migration and Is Regulated by the Chemokine CXCL12 Protein During Restitution*

    PubMed Central

    Hwang, Soonyean; Zimmerman, Noah P.; Agle, Kimberle A.; Turner, Jerrold R.; Kumar, Suresh N.; Dwinell, Michael B.

    2012-01-01

    Chemokines and other immune mediators enhance epithelial barrier repair. The intestinal barrier is established by highly regulated cell-cell contacts between epithelial cells. The goal of these studies was to define the role for the chemokine CXCL12 in regulating E-cadherin during collective sheet migration during epithelial restitution. Mechanisms regulating E-cadherin were investigated using Caco2BBE and IEC-6 model epithelia. Genetic knockdown confirmed a critical role for E-cadherin in in vitro restitution and in vivo wound repair. During restitution, both CXCL12 and TGF-β1 tightened the monolayer by decreasing the paracellular space between migrating epithelial cells. However, CXCL12 differed from TGF-β1 by stimulating the significant increase in E-cadherin membrane localization during restitution. Chemokine-stimulated relocalization of E-cadherin was paralleled by an increase in barrier integrity of polarized epithelium during restitution. CXCL12 activation of its cognate receptor CXCR4 stimulated E-cadherin localization and monolayer tightening through Rho-associated protein kinase activation and F-actin reorganization. These data demonstrate a key role for E-cadherin in intestinal epithelial restitution. PMID:22549778

  7. Anti-inflammatory action of ethanolic extract of Ramulus mori on the BLT2-linked cascade

    PubMed Central

    Park, Geun-Soo; Kim, Jeong-Keun; Kim, Jae-Hong

    2016-01-01

    Mulberry tree twigs (Ramulus mori) contain large amounts of oxyresveratrols and have traditionally been used as herbal medicines because of their anti-inflammatory properties. However, the signaling mechanism by which R. mori exerts its anti-inflammatory action remains to be elucidated. In this study, we observed that R. mori ethanol extracts (RME) exerted an inhibitory effect on the lipopolysaccharide (LPS)-induced production of the pro-inflammatory cytokine interleukin-6 (IL-6) in Raw264.7 macrophage cells. Additionally, RME inhibited IL-6 production by blocking the leukotriene B4 receptor-2 (BLT2)-dependent-NADPH oxidase 1 (NOX1)-reactive oxygen species (ROS) cascade, leading to anti-inflammatory activity. Finally, RME suppressed the production of the BLT2 ligands LTB4 and 12(S)-HETE by inhibiting the p38 kinase-cytosolic phospholipase A2-5-/12-lipoxygenase cascade in LPS-stimulated Raw264.7 cells. Overall, our results suggest that RME inhibits the ‘BLT2 ligand-BLT2’-linked autocrine inflammatory axis, and that this BLT2-linked cascade is one of the targets of the anti-inflammatory action of R. mori. [BMB Reports 2016; 49(4): 232-237] PMID:26879317

  8. Anti-inflammatory action of ethanolic extract of Ramulus mori on the BLT2-linked cascade.

    PubMed

    Park, Geun-Soo; Kim, Jeong-Keun; Kim, Jae-Hong

    2016-04-01

    Mulberry tree twigs (Ramulus mori) contain large amounts of oxyresveratrols and have traditionally been used as herbal medicines because of their anti-inflammatory properties. However, the signaling mechanism by which R. mori exerts its anti-inflammatory action remains to be elucidated. In this study, we observed that R. mori ethanol extracts (RME) exerted an inhibitory effect on the lipopolysaccharide (LPS)-induced production of the pro-inflammatory cytokine interleukin-6 (IL-6) in Raw264.7 macrophage cells. Additionally, RME inhibited IL-6 production by blocking the leukotriene B4 receptor- 2 (BLT2)-dependent-NADPH oxidase 1 (NOX1)-reactive oxygen species (ROS) cascade, leading to anti-inflammatory activity. Finally, RME suppressed the production of the BLT2 ligands LTB4 and 12(S)-HETE by inhibiting the p38 kinase- cytosolic phospholipase A2-5-/12-lipoxygenase cascade in LPS-stimulated Raw264.7 cells. Overall, our results suggest that RME inhibits the 'BLT2 ligand-BLT2'-linked autocrine inflammatory axis, and that this BLT2-linked cascade is one of the targets of the anti-inflammatory action of R. mori. [BMB Reports 2016; 49(4): 232-237]. PMID:26879317

  9. Cadherin-Based Transsynaptic Networks in Establishing and Modifying Neural Connectivity

    PubMed Central

    Friedman, Lauren G.; Benson, Deanna L.; Huntley, George W.

    2015-01-01

    It is tacitly understood that cell adhesion molecules (CAMs) are critically important for the development of cells, circuits, and synapses in the brain. What is less clear is what CAMs continue to contribute to brain structure and function after the early period of development. Here, we focus on the cadherin family of CAMs to first briefly recap their multidimensional roles in neural development and then to highlight emerging data showing that with maturity, cadherins become largely dispensible for maintaining neuronal and synaptic structure, instead displaying new and narrower roles at mature synapses where they critically regulate dynamic aspects of synaptic signaling, structural plasticity, and cognitive function. At mature synapses, cadherins are an integral component of multiprotein networks, modifying synaptic signaling, morphology, and plasticity through collaborative interactions with other CAM family members as well as a variety of neurotransmitter receptors, scaffolding proteins, and other effector molecules. Such recognition of the ever-evolving functions of synaptic cadherins may yield insight into the pathophysiology of brain disorders in which cadherins have been implicated and that manifest at different times of life. PMID:25733148

  10. Cadherin-11 Promotes Invasive Behavior of Fibroblast-like Synoviocytes

    PubMed Central

    Kiener, Hans P.; Niederreiter, Birgit; Lee, David M.; Jimenez-Boj, Esther; Smolen, Josef S.; Brenner, Michael B.

    2009-01-01

    Objective To define the expression pattern of cadherin-11 in destructive pannus tissue of patients with rheumatoid arthritis and to determine if cadherin-11 expression in fibroblast-like synoviocytes controls their invasive capacity. Methods Cadherin-11 expression in rheumatoid synovial tissue was evaluated using immunohistochemistry. To examine the role of cadherin-11 in regulating the invasive behavior of fibroblast-like synoviocytes, we generated L-cell clones expressing wild-type cadherin-11, mutant cadherin-11, and empty vector transfected controls. The invasive capacity of L-cell transfectants and cultured fibroblast-like synoviocytes treated with a blocking cadherin-11-Fc protein or control immunoglobulin was determined in Matrigel invasion assays. Results Immunohistochemistry revealed that cadherin-11 is abundantly expressed in cells at the cartilage-pannus junction in rheumatoid synovitis. Invasion assays demonstrate a twofold increased invasive capacity of cadherin-11 transfected L-cells compared to L-cells transfected with E-cadherin or control vector. The invasive behavior of the L-cells stably transfected with a cadherin-11 construct that lacked the juxta-membrane cytoplasmic domain (cadherin-11 ΔJMD) was diminished to the level of vector control L-cells. Further, treatment with the cadherin-11-Fc fusion protein diminished the invasive capacity of fibroblast-like synoviocytes. Conclusion These in vitro studies implicate a role for cadherin-11 in promoting cell invasion and contribute insight into the invasive nature of fibroblast-like synoviocytes in chronic synovitis and rheumatoid arthritis. PMID:19404963

  11. Cadherin2 (N-cadherin) plays an essential role in zebrafish cardiovascular development

    PubMed Central

    Bagatto, Brian; Francl, Jessie; Liu, Bei; Liu, Qin

    2006-01-01

    Background Cadherins are cell surface adhesion molecules that play important roles in development of vertebrate tissues and organs. We studied cadherin2 expression in developing zebrafish heart using in situ hybridization and immunocytochemical methods, and we found that cadherin2 was strongly expressed by the myocardium of the embryonic zebrafish. To gain insight into cadherin2 role in the formation and function of the heart, we analyzed cardiac differentiation and performance in a cadherin2 mutant, glass onion (glo). Results We found that the cadherin2 mutant had enlarged pericardial cavity, disorganized atrium and ventricle, and reduced expression of a ventricular specific marker vmhc. Individual myocardiocytes in the glo mutant embryos became round shaped and loosely aggregated. In vivo measurements of cardiac performance revealed that the mutant heart had significantly reduced heart rate, stroke volume and cardiac output compared to control embryos. Formation of the embryonic vascular system in the glo mutants was also affected. Conclusion Our results suggest that cadherin2 plays an essential role in zebrafish cardiovascular development. Although the exact mechanisms remain unknown as to the formation of the enlarged pericardium and reduced peripheral blood flow, it is clear that myocardiocyte differentiation and physiological cardiovascular performance is impaired when cadherin2 function is disrupted. PMID:16719917

  12. N-cadherin relocalization during cardiac trabeculation.

    PubMed

    Cherian, Anoop V; Fukuda, Ryuichi; Augustine, Sruthy Maria; Maischein, Hans-Martin; Stainier, Didier Y R

    2016-07-01

    During cardiac trabeculation, cardiomyocytes delaminate from the outermost (compact) layer to form complex muscular structures known as trabeculae. As these cardiomyocytes delaminate, the remodeling of adhesion junctions must be tightly coordinated so cells can extrude from the compact layer while remaining in tight contact with their neighbors. In this study, we examined the distribution of N-cadherin (Cdh2) during cardiac trabeculation in zebrafish. By analyzing the localization of a Cdh2-EGFP fusion protein expressed under the control of the zebrafish cdh2 promoter, we initially observed Cdh2-EGFP expression along the lateral sides of embryonic cardiomyocytes, in an evenly distributed pattern, and with the occasional appearance of punctae. Within a few hours, Cdh2-EGFP distribution on the lateral sides of cardiomyocytes evolves into a clear punctate pattern as Cdh2-EGFP molecules outside the punctae cluster to increase the size of these aggregates. In addition, Cdh2-EGFP molecules also appear on the basal side of cardiomyocytes that remain in the compact layer. Delaminating cardiomyocytes accumulate Cdh2-EGFP on the surface facing the basal side of compact layer cardiomyocytes, thereby allowing tight adhesion between these layers. Importantly, we find that blood flow/cardiac contractility is required for the transition from an even distribution of Cdh2-EGFP to the formation of punctae. Furthermore, using time-lapse imaging of beating hearts in conjunction with a Cdh2 tandem fluorescent protein timer transgenic line, we observed that Cdh2-EGFP molecules appear to move from the lateral to the basal side of cardiomyocytes along the cell membrane, and that Erb-b2 receptor tyrosine kinase 2 (Erbb2) function is required for this relocalization. PMID:27339140

  13. Differential Function of N-Cadherin and Cadherin-7 in the Control of Embryonic Cell Motility

    PubMed Central

    Dufour, Sylvie; Beauvais-Jouneau, Alice; Delouvée, Annie; Thiery, Jean Paul

    1999-01-01

    Similar amounts of N-cadherin and cadherin-7, the prototypes of type I and type II cadherin, induced cell-cell adhesion in murine sarcoma 180 transfectants, Ncad-1 and cad7-29, respectively. However, in the initial phase of aggregation, Ncad-1 cells aggregated more rapidly than cad7-29 cells. Isolated Ncad-1 and cad7-29 cells adhered and spread in a similar manner on fibronectin (FN), whereas aggregated cad7-29 cells were more motile and dispersed than aggregated Ncad-1 cells. cad7-29 cells established transient contacts with their neighbors which were stabilized if FN-cell interactions were perturbed. In contrast, Ncad-1 cells remained in close contact when they migrated on FN. Both β-catenin and cadherin were more rapidly downregulated in cad7-29 than in Ncad-1 cells treated with cycloheximide, suggesting a higher turnover rate for cadherin-7–mediated cell-cell contacts than for those mediated by N-cadherin. The extent of FN-dependent focal adhesion kinase phosphorylation was much lower if the cells had initiated N-cadherin–mediated rather than cadherin-7–mediated cell adhesion before plating. On grafting into the embryo, Ncad-1 cells did not migrate and remained at or close to the graft site, even after 48 h, whereas grafted cad7-29 cells dispersed efficiently into embryonic structures. Thus, the adhesive phenotype of cadherin-7–expressing cells is regulated by the nature of the extracellular matrix environment which also controls the migratory behavior of the cells. In addition, adhesions mediated by different cadherins differentially regulate FN-dependent signaling. The transient contacts specifically observed in cadherin- 7–expressing cells may also be important in the control of cell motility. PMID:10427101

  14. Cadherin selectivity filter regulates endothelial sieving properties

    PubMed Central

    Quadri, Sadiqa K.; Sun, Li; Islam, Mohammad Naimul; Shapiro, Lawrence; Bhattacharya, Jahar

    2013-01-01

    The molecular basis of endothelial protein sieving, the critical vascular barrier function that restricts flow of large plasma proteins into tissues while allowing small molecules and water to pass, is not understood. Here, we address this issue using a novel assay to detect macromolecular penetrance at microdomains of endothelial adherens junctions. Adherens junctions, as detected by cadherin-GFP expression, were distributed in the cell perimeter as high- or low-density segments. Low but not high-density segments permitted penetrance of a 70-kDa fluorescent dextran, a molecule of equivalent size to albumin. Expression of a cadherin mutant that abrogates strand–swap adhesive binding in the cadherin EC1 ectodomain, or alternatively of an α-actinin-1 mutant that inhibits F-actin bundling, increased both cadherin mobility and 70 kDa dextran penetrance at high-density segments. These findings suggest that adhesive interactions in the cadherin EC1 domain, which underlie adherens junction structure, are critical determinants of endothelial macromolecular sieving. PMID:23033075

  15. Hypotonic stress induces E-cadherin expression in cultured human keratinocytes.

    PubMed

    Kippenberger, Stefan; Loitsch, Stefan; Guschel, Maike; Müller, Jutta; Kaufmann, Roland; Bernd, August

    2005-01-01

    Human epidermis marks the interface between internal and external environments with the major task being to maintain body hydration. Alternating exposure of skin to a dry or humid environment is likely to cause changes in the epidermal water gradient resulting in osmotic alterations of epidermal keratinocytes. The present in vitro approach studied the effect of hypotonicity on cell-cell contact. It was demonstrated that hypotonic stress applied to human epithelial cells (HaCaT, A-431) induced upregulation of E-cadherin at both, the protein and mRNA level. 5'-deletional mutants of the E-cadherin promoter identified an element ranging from -53 to +31 that conveyed strong transactivation under hypotonic stress. In order to define relevant upstream regulators members of the MAP kinase family, the epidermal growth factor receptor (EGFR) and protein kinase B/Akt (PKB/Akt) were investigated. Hypotonic conditions led to a fast activation of ERK1/2, SAPK/JNK, p38, EGFR and PKB/Akt with distinct activation patterns. Experiments using specific inhibitors showed that p38 contributes to the E-cadherin transactivation under hypotonic conditions. Further upstream, adhesion was found to be a prerequisite for E-cadherin transactivation in this model. In summary, the present study provides evidence that E-cadherin is an osmo-sensitive gene that responds to hypotonic stress. The function of this regulation may be found in morphological changes induced by cell swelling. It is likely that induction of E-cadherin contributes to the stabilization between adjacent cells in order to withstand the physical forces induced by hypotonicity. PMID:15620715

  16. Materials Fabrication from Bombyx mori Silk Fibroin

    PubMed Central

    Rockwood, Danielle N.; Preda, Rucsanda C.; Yücel, Tuna; Wang, Xiaoqin; Lovett, Michael L.; Kaplan, David L.

    2013-01-01

    Silk fibroin, derived from Bombyx mori cocoons, is a widely used and studied protein polymer for biomaterial applications. Silk fibroin has remarkable mechanical properties when formed into different materials, demonstrates biocompatibility, has controllable degradation rates from hours to years, and it can be chemically modified to alter surface properties or to immobilize growth factors. A variety of aqueous or organic solvent processing methods can be used to generate silk biomaterials for a range of applications. In this protocol we include methods to extract silk from B. mori cocoons in order to fabricate hydrogels, tubes, sponges, composites, fibers, microspheres and thin films. These materials can be used directly as biomaterials for implants, as scaffolding in tissue engineering and in vitro disease models, and for drug delivery. PMID:21959241

  17. BmRobo2/3 is required for axon guidance in the silkworm Bombyx mori.

    PubMed

    Li, Xiao-Tong; Yu, Qi; Zhou, Qi-Sheng; Zhao, Xiao; Liu, Zhao-Yang; Cui, Wei-Zheng; Liu, Qing-Xin

    2016-02-15

    Axon guidance is critical for proper wiring of the nervous system. During the neural development, the axon guidance molecules play a key role and direct axons to choose the correct way to reach the target. Robo, as the receptor of axon guidance molecule Slit, is evolutionarily conserved from planarians to humans. However, the function of Robo in the silkworm, Bombyx mori, remained unknown. In this study, we cloned robo2/3 from B. mori (Bmrobo2/3), a homologue of robo2/3 in Tribolium castaneum. Moreover, BmRobo2/3 was localized in the neuropil, and RNAi-mediated knockdown of Bmrobo2/3 resulted in the longitudinal connectives forming closer to the midline. These data demonstrate that BmRobo2/3 is required for axon guidance in the silkworm. PMID:26625973

  18. Ankyrin-G Inhibits Endocytosis of Cadherin Dimers.

    PubMed

    Cadwell, Chantel M; Jenkins, Paul M; Bennett, Vann; Kowalczyk, Andrew P

    2016-01-01

    Dynamic regulation of endothelial cell adhesion is central to vascular development and maintenance. Furthermore, altered endothelial adhesion is implicated in numerous diseases. Therefore, normal vascular patterning and maintenance require tight regulation of endothelial cell adhesion dynamics. However, the mechanisms that control junctional plasticity are not fully understood. Vascular endothelial cadherin (VE-cadherin) is an adhesive protein found in adherens junctions of endothelial cells. VE-cadherin mediates adhesion through trans interactions formed by its extracellular domain. Trans binding is followed by cis interactions that laterally cluster the cadherin in junctions. VE-cadherin is linked to the actin cytoskeleton through cytoplasmic interactions with β- and α-catenin, which serve to increase adhesive strength. Furthermore, p120-catenin binds to the cytoplasmic tail of cadherin and stabilizes it at the plasma membrane. Here we report that induced cis dimerization of VE-cadherin inhibits endocytosis independent of both p120 binding and trans interactions. However, we find that ankyrin-G, a protein that links membrane proteins to the spectrin-actin cytoskeleton, associates with VE-cadherin and inhibits its endocytosis. Ankyrin-G inhibits VE-cadherin endocytosis independent of p120 binding. We propose a model in which ankyrin-G associates with and inhibits the endocytosis of VE-cadherin cis dimers. Our findings support a novel mechanism for regulation of VE-cadherin endocytosis through ankyrin association with cadherin engaged in lateral interactions. PMID:26574545

  19. Characteristics of bladder transitional cell carcinoma with E-cadherin and N-cadherin double-negative expression

    PubMed Central

    LUO, YANG; ZHU, YONG-TONG; MA, LI-LI; PANG, SHI-YU; WEI, LI-JIE; LEI, CHENG-YONG; HE, CHENG-WU; TAN, WAN-LONG

    2016-01-01

    The aim of the present study was to examine the characteristics of bladder transitional cell carcinoma with E-cadherin and N-cadherin double-negative expression. An immunofluorescence assay was used to detect E-cadherin and N-cadherin expression in infiltrative bladder cancer tissues, and immunofluorescence and western blot analysis were used to detect E-cadherin and N-cadherin expression in human urinary bladder grade II carcinoma 5637, transitional cell carcinoma UMUC-3 and invasive bladder carcinoma EJ cells. Cell proliferation, migration, invasion and plate colony formation assays were used to detect the proliferative, migratory and invasive abilities and the efficiency of plate colony formation of 5637, UMUC3 and EJ cells. A tumor xenograft formation assay was used to evaluate the tumorigenic abilities of 5637, UMUC-3 and EJ cells in vivo. E-cadherin and N-cadherin double-negative expression was identified in various pathological grades of infiltrative bladder cancers. E-cadherin positive and N-cadherin negative expression was exhibited by 5637 cells. By contrast, E-cadherin negative and N-cadherin positive expression was exhibited by EJ cells, and E-cadherin and N-cadherin double-negative expression was exhibited by UMUC-3 cells. The ability of cells to proliferate, migrate, invade, and the efficiency of plate colony formation and tumorigenic abilities of the cells were significantly different among 5637, UMUC-3 and EJ cells. These cell characteristics were significantly increased in UMUC-3 cells compared with 5637 cells; however, the characteristics were significantly decreased compared with EJ cells. The biological characteristics of bladder cancer cells with E-cadherin and N-cadherin double-negative expression was between bladder cancer cells that exhibited a E-cadherin positive and N-cadherin negative expression, and bladder cancer cells that exhibited E-cadherin negative and N-cadherin positive expression. The present study deduces that the status of E-cadherin

  20. E-cadherin, N-cadherin Expression and Histologic Characterization of Canine Choroid Plexus Tumors.

    PubMed

    Reginato, A; Girolami, D; Menchetti, L; Foiani, G; Mandara, M T

    2016-07-01

    Choroid plexus tumors (CPTs) are reported with an increasing incidence in dogs, and they call for a reexamination of histologic features and criteria of classification corresponding to their biological behavior. In this study, the human World Health Organization classification was applied to 16 canine CPTs, and the expression of molecules involved in neoplastic cell adhesion (E-cadherin, N-cadherin), invasion (doublecortin), and proliferation (Ki-67) was investigated. Mitotic index was found to be the main criterion for grading CPTs. Cell density and multilayering of papillae were also statistically associated with histologic grade. Intraventricular spread and parenchymal invasion was observed for tumors showing histologic benign features. E-cadherin was expressed in all CPT grades, independent of tumor invasion. N-cadherin immunolabeling was more expressed in grade I than high-grade CPTs, whereas doublecortin expression was not detected in CPTs. An increasing proliferative activity was observed in relation with histologic grade. PMID:26792846

  1. The classic cadherins in synaptic specificity

    PubMed Central

    Basu, Raunak; Taylor, Matthew R; Williams, Megan E

    2015-01-01

    During brain development, billions of neurons organize into highly specific circuits. To form specific circuits, neurons must build the appropriate types of synapses with appropriate types of synaptic partners while avoiding incorrect partners in a dense cellular environment. Defining the cellular and molecular rules that govern specific circuit formation has significant scientific and clinical relevance because fine scale connectivity defects are thought to underlie many cognitive and psychiatric disorders. Organizing specific neural circuits is an enormously complicated developmental process that requires the concerted action of many molecules, neural activity, and temporal events. This review focuses on one class of molecules postulated to play an important role in target selection and specific synapse formation: the classic cadherins. Cadherins have a well-established role in epithelial cell adhesion, and although it has long been appreciated that most cadherins are expressed in the brain, their role in synaptic specificity is just beginning to be unraveled. Here, we review past and present studies implicating cadherins as active participants in the formation, function, and dysfunction of specific neural circuits and pose some of the major remaining questions. PMID:25837840

  2. Relation of glypican-3 and E-cadherin expressions to clinicopathological features and prognosis of mucinous and non-mucinous colorectal adenocarcinoma.

    PubMed

    Foda, Abd Al-Rahman Mohammad; Mohammad, Mie Ali; Abdel-Aziz, Azza; El-Hawary, Amira Kamal

    2015-06-01

    Glypican-3 (GPC3) is a member of the membrane-bound heparin sulfate proteoglycans. E-cadherin is an adhesive receptor that is believed to act as a tumor suppressor gene. Many studies had investigated E-cadherin expressions in colorectal carcinoma (CRC) while only one study had investigated GPC3 expression in CRC. This study aims to investigate expression of GCP3 and E-cadherin in colorectal mucinous carcinoma (MA) and non-mucinous adenocarcinoma (NMA) using manual tissue microarray technique. Tumor tissue specimens are collected from 75 cases of MC and 75 cases of NMA who underwent radical surgery from Jan 2007 to Jan 2012 at the Gastroenterology Centre, Mansoura University, Egypt. Their clinicopathological parameters and survival data were revised and analyzed using established statistical methodologies. High-density manual tissue microarrays were constructed using modified mechanical pencil tip technique and immunohistochemistry for GPC3 and E-cadherin was done. NMA showed higher expression of GPC3 than MA with no statistically significant relation. NMA showed a significantly higher E-cadherin expression than MA. GPC3 and E-cadherin positivity rates were significantly interrelated in NMA, but not in MA, group. In NMA group, there was no significant relation between either GPC3 or E-cadherin expression and the clinicopathological features. In a univariate analysis, neither GPC3 nor E-cadherin expression showed a significant impact on disease-free survival (DFS) or overall survival (OS). GPC3 and E-cadherin expressions are not independent prognostic factors in CRC. However, expressions of both are significantly interrelated in NMA patients, suggesting an excellent interplay between both, in contrast to MA. Further molecular studies are needed to further explore the relationship between GCP3 and E-cadherin in colorectal carcinogenesis. PMID:25619476

  3. Cadherin Cell Adhesion System in Canine Mammary Cancer: A Review

    PubMed Central

    Gama, Adelina; Schmitt, Fernando

    2012-01-01

    Cadherin-catenin adhesion complexes play important roles by providing cell-cell adhesion and communication in different organ systems. Abnormal expression of cadherin adhesion molecules constitutes a common phenomenon in canine mammary cancer and has been frequently implicated in tumour progression. This paper summarizes the current knowledge on cadherin/catenin adhesion molecules (E-cadherin, β-catenin, and P-cadherin) in canine mammary cancer, focusing on the putative biological functions and clinical significance of these molecules in this disease. This paper highlights the need for further research studies in this setting in order to elucidate the role of these adhesion molecules during tumour progression and metastasis. PMID:22973534

  4. Fusobacterium nucleatum adhesin FadA binds vascular-endothelial cadherin and alters endothelial integrity

    PubMed Central

    Fardini, Yann; Wang, Xiaowei; Témoin, Stéphanie; Nithianantham, Stanley; Lee, David; Shoham, Menachem; Han, Yiping W.

    2011-01-01

    SUMMARY Fusobacterium nucleatum is a gram-negative oral anaerobe, capable of systemic dissemination causing infections and abscesses, often in mixed-species, at different body sites. We have shown previously that F. nucleatum adheres to and invades host epithelial and endothelial cells via a novel FadA adhesin. In this study, vascular endothelial (VE)-cadherin, a member of the cadherin family and a cell-cell junction molecule, was identified as the endothelial receptor for FadA, required for F. nucleatum binding to the cells. FadA co-localized with VE-cadherin on endothelial cells, causing relocation of VE-cadherin away from the cell-cell junctions. As a result, the endothelial permeability was increased, allowing the bacteria to cross the endothelium through loosened junctions. This crossing mechanism may explain why the organism is able to disseminate systemically to colonize in different body sites and even overcome the placental and blood-brain barriers. Co-incubation of F. nucleatum and E. coli enhanced penetration of the endothelial cells by the latter in the transwell assays, suggesting F. nucleatum may serve as an “enabler” for other microorganisms to spread systemically. This may explain why F. nucleatum is often found in mixed infections. This study reveals a possible novel dissemination mechanism utilized by pathogens. PMID:22040113

  5. Variability in the cadherin gene in an Ostrinia nubilalis strain selected for Cry1Ab resistance.

    PubMed

    Bel, Yolanda; Siqueira, Herbert A A; Siegfried, Blair D; Ferré, Juan; Escriche, Baltasar

    2009-03-01

    Transgenic corn expressing Cry1Ab (a Bacillus thuringiensis toxin) is highly effective in the control of Ostrinia nubilalis. For its toxic action, Cry1Ab has to bind to specific insect midgut proteins. To date, in three Lepidoptera species resistance to a Cry1A toxin has been conferred by mutations in cadherin, a protein of the Lepidoptera midgut membrane. The implication of cadherin in the resistance of an Ostrinia nubilalis colony (Europe-R) selected with Bacillus thuringiensis Cry1Ab protoxin was investigated. Several major mutations in the cadherin (cdh) gene were found, which introduced premature termination codons and/or large deletions (ranging from 1383 to 1701bp). The contribution of these major mutations to the resistance was analyzed in resistant individuals that survived exposure to a high concentration of Cry1Ab protoxin. The results indicated that the presence of major mutations was drastically reduced in individuals that survived exposure. Previous inheritance experiments with the Europe-R strain indicated the involvement of more than one genetic locus and reduced amounts of the cadherin receptor. The results of the present work support a polygenic inheritance of resistance in the Europe-R strain, in which mutations in the cdh gene would contribute to resistance by means of an additive effect. PMID:19114103

  6. VE-cadherin facilitates BMP-induced endothelial cell permeability and signaling.

    PubMed

    Benn, Andreas; Bredow, Clara; Casanova, Isabel; Vukičević, Slobodan; Knaus, Petra

    2016-01-01

    Several vascular disorders, such as aberrant angiogenesis, atherosclerosis and pulmonary hypertension, have been linked to dysfunctional BMP signaling. Vascular hyperpermeability via distortion of endothelial cell adherens junctions is a common feature of these diseases, but the role of BMPs in this process has not been investigated. BMP signaling is initiated by binding of ligand to, and activation of, BMP type I (BMPRI) and type II (BMPRII) receptors. Internalization of VE-cadherin as well as c-Src kinase-dependent phosphorylation have been implicated in the loosening of cell-cell contacts, thereby modulating vascular permeability. Here we demonstrate that BMP6 induces hyperpermeabilization of human endothelial cells by inducing internalization and c-Src-dependent phosphorylation of VE-cadherin. Furthermore, we show BMP-dependent physical interaction of VE-cadherin with the BMP receptor ALK2 (BMPRI) and BMPRII, resulting in stabilization of the BMP receptor complex and, thereby, the support of BMP6-Smad signaling. Our results provide first insights into the molecular mechanism of BMP-induced vascular permeability, a hallmark of various vascular diseases, and provide the basis for further investigations of BMPs as regulators of vascular integrity, both under physiological and pathophysiological conditions. PMID:26598555

  7. VE-cadherin facilitates BMP-induced endothelial cell permeability and signaling

    PubMed Central

    Benn, Andreas; Bredow, Clara; Casanova, Isabel; Vukičević, Slobodan; Knaus, Petra

    2016-01-01

    ABSTRACT Several vascular disorders, such as aberrant angiogenesis, atherosclerosis and pulmonary hypertension, have been linked to dysfunctional BMP signaling. Vascular hyperpermeability via distortion of endothelial cell adherens junctions is a common feature of these diseases, but the role of BMPs in this process has not been investigated. BMP signaling is initiated by binding of ligand to, and activation of, BMP type I (BMPRI) and type II (BMPRII) receptors. Internalization of VE-cadherin as well as c-Src kinase-dependent phosphorylation have been implicated in the loosening of cell–cell contacts, thereby modulating vascular permeability. Here we demonstrate that BMP6 induces hyperpermeabilization of human endothelial cells by inducing internalization and c-Src-dependent phosphorylation of VE-cadherin. Furthermore, we show BMP-dependent physical interaction of VE-cadherin with the BMP receptor ALK2 (BMPRI) and BMPRII, resulting in stabilization of the BMP receptor complex and, thereby, the support of BMP6-Smad signaling. Our results provide first insights into the molecular mechanism of BMP-induced vascular permeability, a hallmark of various vascular diseases, and provide the basis for further investigations of BMPs as regulators of vascular integrity, both under physiological and pathophysiological conditions. PMID:26598555

  8. Specific Activation of the G Protein-coupled Receptor BNGR-A21 by the Neuropeptide Corazonin from the Silkworm, Bombyx mori, Dually Couples to the Gq and Gs Signaling Cascades*

    PubMed Central

    Yang, Jingwen; Huang, Haishan; Yang, Huipeng; He, Xiaobai; Jiang, Xue; Shi, Ying; Alatangaole, Damirin; Shi, Liangen; Zhou, Naiming

    2013-01-01

    Corazonin, an undecapeptide neurohormone sharing a highly conserved amino acid sequence across Insecta, plays different physiological roles in the regulation of heart contraction rates, silk spinning rates, the induction of dark color and morphometric phase changes, and ecdysis. Corazonin receptors have been identified in Drosophila melanogaster, Manduca sexta, and Musca domestica. However, detailed information on the signaling and major physiological functions of corazonin and its receptor is largely unknown. In the current study, using both the mammalian cell line HEK293 and insect cell lines BmN and Sf21, we paired the Bombyx corazonin neuropeptide as a specific endogenous ligand for the Bombyx neuropeptide G protein-coupled receptor A21 (BNGR-A21), and we therefore designated this receptor as BmCrzR. Further characterization indicated that synthetic BmCrz demonstrated a high affinity for and activated BmCrzR, resulting in intracellular cAMP accumulation, Ca2+ mobilization, and ERK1/2 phosphorylation via the Gq- and Gs-coupled signaling pathways. The direct interaction of BmCrzR with BmCrz was confirmed by a rhodamine-labeled BmCrz peptide. Moreover, experiments with double-stranded RNA and synthetic peptide injection suggested a possible role of BmCrz/BmCrzR in the regulation of larval growth and spinning rate. Our present results provide the first in-depth information on BmCrzR-mediated signaling for further elucidation of the BmCrz/BmCrzR system in the regulation of fundamental physiological processes. PMID:23457297

  9. Structural, evolutionary and functional analysis of APN genes in the Lepidoptera Bombyx mori.

    PubMed

    Lin, Ping; Cheng, Tingcai; Jin, Shengkai; Jiang, Liang; Wang, Chen; Xia, Qingyou

    2014-02-10

    Aminopeptidases N (APNs), the receptors of Bacillus thuringiensis (Bt) toxin in the lepidopteran midgut, are involved in the Bt pathogen infection mechanism. In the present work, we screened 102 APNs from SilkDB, ButterflyBase and MonarchBase; 16 APNs were identified from the silkworm (Bombyx mori) and 24 from the monarch butterfly (Danaus plexippus). Syntenic and phylogenetic tree analysis showed that APN genes have developed multi-family genes before evolutionary divergence of the Lepidoptera. The tissue-expression pattern shows some BmAPNs are specifically or highly expressed in the midgut. Bacillus bombysepticus (Bb) is a specific pathogen of B. mori, leading to acute fuliginosa septicemia of the larva. BmAPNs were modulated by real time quantitative reverse transcription polymerase chain reaction (qRT-PCR) analysis after Bb or Bt oral infection. There were different patterns of induced expression between Bb and Bt challenges, suggesting that B. mori has different responses to infection by the specific pathogen Bb and the nonspecific pathogen Bt. Research on BmAPNs will help us to better understand the evolutionary conservation and functions in Bb or Bt pathogen interaction with the host and to apply this knowledge in agricultural and forestry pest control. PMID:24286860

  10. Gastrulation EMT Is Independent of P-Cadherin Downregulation

    PubMed Central

    Moly, Pricila K.; Cooley, James R.; Zeltzer, Sebastian L.; Yatskievych, Tatiana A.

    2016-01-01

    Epithelial-mesenchymal transition (EMT) is an evolutionarily conserved process during which cells lose epithelial characteristics and gain a migratory phenotype. Although downregulation of epithelial cadherins by Snail and other transcriptional repressors is generally considered a prerequisite for EMT, recent studies have challenged this view. Here we investigate the relationship between E-cadherin and P-cadherin expression and localization, Snail function and EMT during gastrulation in chicken embryos. Expression analyses show that while E-cadherin transcripts are detected in the epiblast but not in the primitive streak or mesoderm, P-cadherin mRNA and protein are present in the epiblast, primitive and mesoderm. Antibodies that specifically recognize E-cadherin are not presently available. During EMT, P-cadherin relocalizes from the lateral surfaces of epithelial epiblast cells to a circumferential distribution in emerging mesodermal cells. Cells electroporated with an E-cadherin expression construct undergo EMT and migrate into the mesoderm. An examination of Snail function showed that reduction of Slug (SNAI2) protein levels using a morpholino fails to inhibit EMT, and expression of human or chicken Snail in epiblast cells fails to induce EMT. In contrast, cells expressing the Rho inhibitor peptide C3 rapidly exit the epiblast without activating Slug or the mesoderm marker N-cadherin. Together, these experiments show that epiblast cells undergo EMT while retaining P-cadherin, and raise questions about the mechanisms of EMT regulation during avian gastrulation. PMID:27097030

  11. Linkage of N-cadherin to multiple cytoskeletal elements revealed by a proteomic approach in hippocampal neurons.

    PubMed

    Tanaka, Hidekazu; Takafuji, Kazuaki; Taguchi, Akihiko; Wiriyasermkul, Pattama; Ohgaki, Ryuichi; Nagamori, Shushi; Suh, Pann-Ghill; Kanai, Yoshikatsu

    2012-07-01

    The CNS synapse is an adhesive junction differentiated for chemical neurotransmission and is equipped with presynaptic vesicles and postsynaptic neurotransmitter receptors. Cell adhesion molecule cadherins not only maintain connections between pre- and postsynaptic membranes but also modulate the efficacy of synaptic transmission. Although the components of the cadherin-mediated adhesive apparatus have been studied extensively in various cell systems, the complete picture of these components, particularly at the synaptic junction, remains elusive. Here, we describe the proteomic assortment of the N-cadherin-mediated synaptic adhesion apparatus in cultured hippocampal neurons. N-cadherin immunoprecipitated from Triton X-100-solubilized neuronal extract contained equal amounts of β- and α-catenins, as well as F-actin-related membrane anchor proteins such as integrins bridged with α-actinin-4, and Na(+)/K(+)-ATPase bridged with spectrins. A close relative of β-catenin, plakoglobin, and its binding partner, desmoplakin, were also found, suggesting that a subset of the N-cadherin-mediated adhesive apparatus also anchors intermediate filaments. Moreover, dynein heavy chain and LEK1/CENPF/mitosin were found. This suggests that internalized pools of N-cadherin in trafficking vesicles are conveyed by dynein motors on microtubules. In addition, ARVCF and NPRAP/neurojungin/δ2-catenin, but not p120ctn/δ1-catenin or plakophilins-1, -2, -3, -4 (p0071), were found, suggesting other possible bridges to microtubules. Finally, synaptic stimulation by membrane depolarization resulted in an increased 93-kDa band, which corresponded to proteolytically truncated β-catenin. The integration of three different classes of cytoskeletal systems found in the synaptic N-cadherin complex may imply a dynamic switching of adhesive scaffolds in response to synaptic activity. PMID:22609377

  12. E-cadherin mediates contact inhibition of proliferation through Hippo signaling-pathway components

    PubMed Central

    Kim, Nam-Gyun; Koh, Eunjin; Chen, Xiao; Gumbiner, Barry M.

    2011-01-01

    Contact inhibition of cell growth is essential for embryonic development and maintenance of tissue architecture in adult organisms, and the growth of tumors is characterized by a loss of contact inhibition of proliferation. The recently identified Hippo signaling pathway has been implicated in contact inhibition of proliferation as well as organ size control. The modulation of the phosphorylation and nuclear localization of Yes-associated protein (YAP) by the highly conserved kinase cascade of the Hippo signaling pathway has been intensively studied. However, cell-surface receptors regulating the Hippo signaling pathway in mammals are not well understood. In this study, we show that Hippo signaling pathway components are required for E-cadherin–dependent contact inhibition of proliferation. Knockdown of the Hippo signaling components or overexpression of YAP inhibits the decrease in cell proliferation caused by E-cadherin homophilic binding at the cell surface, independent of other cell–cell interactions. We also demonstrate that the E-cadherin/catenin complex functions as an upstream regulator of the Hippo signaling pathway in mammalian cells. Expression of E-cadherin in MDA-MB-231 cells restores the density-dependent regulation of YAP nuclear exclusion. Knockdown of β-catenin in densely cultured MCF10A cells, which mainly depletes E-cadherin–bound β-catenin, induces a decrease in the phosphorylation of S127 residue of YAP and its nuclear accumulation. Moreover, E-cadherin homophilic binding independent of other cell interactions is sufficient to control the subcellular localization of YAP. Therefore, Our results indicate that, in addition to its role in cell–cell adhesion, E-cadherin-mediated cell–cell contact directly regulates the Hippo signaling pathway to control cell proliferation. PMID:21730131

  13. N-cadherin prodomain processing regulates synaptogenesis.

    PubMed

    Reinés, Analía; Bernier, Louis-Philippe; McAdam, Robyn; Belkaid, Wiam; Shan, Weisong; Koch, Alexander W; Séguéla, Philippe; Colman, David R; Dhaunchak, Ajit S

    2012-05-01

    Classical cadherins, which are adhesion molecules functioning at the CNS synapse, are synthesized as adhesively inactive precursor proteins in the endoplasmic reticulum (ER). Signal sequence and prodomain cleavage in the ER and Golgi apparatus, respectively, activates their adhesive properties. Here, we provide the first evidence for sorting of nonadhesive precursor N-cadherin (ProN) to the neuronal surface, where it coexists with adhesively competent mature N-cadherin (N-cad), generating a spectrum of adhesive strengths. In cultured hippocampal neurons, a high ProN/N-cad ratio downregulates synapse formation. Neurons expressing genetically engineered uncleavable ProN make markedly fewer synapses. The synapse number can be rescued to normality by depleting surface ProN levels through prodomain cleavage by an exogenous protease. Finally, prodomain processing is developmentally regulated in the rat hippocampus. We conclude that it is the ProN/N-cad ratio and not mature N-cad alone that is critical for regulation of adhesion during synaptogenesis. PMID:22553038

  14. Slit1b-Robo3 signaling and N-cadherin regulate apical process retraction in developing retinal ganglion cells

    PubMed Central

    Wong, Grace K W; Baudet, Marie-Laure; Norden, Caren; Leung, Louis; Harris, William A.

    2012-01-01

    When neurons exit the cell cycle after their terminal mitosis, they detach from the apical surface of the neuroepithelium. Despite the fact that this detachment is crucial for further neurogenesis and neuronal migration, the underlying mechanisms are still not understood. Here, taking advantage of the genetics and imaging possibilities of the zebrafish retina as a model system, we show by knock down experiments that the guidance molecule Slit1b as well as its receptor Robo3 are required for apical retraction of retinal ganglion cells (RGCs). In contrast, N-cadherin seems to be responsible for maintenance of apical attachment as expression of dominant-negative N-cadherin causes RGCs to lose apical attachments prematurely and rescues retraction in slit1b morphants. These results suggest that Slit-Robo signaling downregulates N-cadherin activity to allow apical retraction in newly generated RGCs. PMID:22219284

  15. Slit1b-Robo3 signaling and N-cadherin regulate apical process retraction in developing retinal ganglion cells.

    PubMed

    Wong, Grace K W; Baudet, Marie-Laure; Norden, Caren; Leung, Louis; Harris, William A

    2012-01-01

    When neurons exit the cell cycle after their terminal mitosis, they detach from the apical surface of the neuroepithelium. Despite the fact that this detachment is crucial for further neurogenesis and neuronal migration, the underlying mechanisms are still not understood. Here, taking advantage of the genetics and imaging possibilities of the zebrafish retina as a model system, we show by knockdown experiments that the guidance molecule Slit1b and its receptor Robo3 are required for apical retraction of retinal ganglion cells (RGCs). In contrast, N-cadherin seems to be responsible for maintenance of apical attachment, as expression of dominant-negative N-cadherin causes RGCs to lose apical attachments prematurely and rescues retraction in slit1b morphants. These results suggest that Slit-Robo signaling downregulates N-cadherin activity to allow apical retraction in newly generated RGCs. PMID:22219284

  16. Cadherins and catenins in dendrite and synapse morphogenesis

    PubMed Central

    Seong, Eunju; Yuan, Li; Arikkath, Jyothi

    2015-01-01

    Neurons are highly polarized specialized cells. Neuronal integrity and functional roles are critically dependent on dendritic architecture and synaptic structure, function and plasticity. The cadherins are glycosylated transmembrane proteins that form cell adhesion complexes in various tissues. They are associated with a group of cytosolic proteins, the catenins. While the functional roles of the complex have been extensively investigates in non-neuronal cells, it is becoming increasingly clear that components of the complex have critical roles in regulating dendritic and synaptic architecture, function and plasticity in neurons. Consistent with these functional roles, aberrations in components of the complex have been implicated in a variety of neurodevelopmental disorders. In this review, we discuss the roles of the classical cadherins and catenins in various aspects of dendrite and synapse architecture and function and their relevance to human neurological disorders. Cadherins are glycosylated transmembrane proteins that were initially identified as Ca2+-dependent cell adhesion molecules. They are present on plasma membrane of a variety of cell types from primitive metazoans to humans. In the past several years, it has become clear that in addition to providing mechanical adhesion between cells, cadherins play integral roles in tissue morphogenesis and homeostasis. The cadherin family is composed of more than 100 members and classified into several subfamilies, including classical cadherins and protocadherins. Several of these cadherin family members have been implicated in various aspects of neuronal development and function.1-3 The classical cadherins are associated with a group of cytosolic proteins, collectively called the catenins. While the functional roles of the cadherin-catenin cell adhesion complex have been extensively investigated in epithelial cells, it is now clear that components of the complex are well expressed in central neurons at different

  17. Hepatitis C virus depends on E-cadherin as an entry factor and regulates its expression in epithelial-to-mesenchymal transition.

    PubMed

    Li, Qisheng; Sodroski, Catherine; Lowey, Brianna; Schweitzer, Cameron J; Cha, Helen; Zhang, Fang; Liang, T Jake

    2016-07-01

    Hepatitis C virus (HCV) enters the host cell through interactions with a cascade of cellular factors. Although significant progress has been made in understanding HCV entry, the precise mechanisms by which HCV exploits the receptor complex and host machinery to enter the cell remain unclear. This intricate process of viral entry likely depends on additional yet-to-be-defined cellular molecules. Recently, by applying integrative functional genomics approaches, we identified and interrogated distinct sets of host dependencies in the complete HCV life cycle. Viral entry assays using HCV pseudoparticles (HCVpps) of various genotypes uncovered multiple previously unappreciated host factors, including E-cadherin, that mediate HCV entry. E-cadherin silencing significantly inhibited HCV infection in Huh7.5.1 cells, HepG2/miR122/CD81 cells, and primary human hepatocytes at a postbinding entry step. Knockdown of E-cadherin, however, had no effect on HCV RNA replication or internal ribosomal entry site (IRES)-mediated translation. In addition, an E-cadherin monoclonal antibody effectively blocked HCV entry and infection in hepatocytes. Mechanistic studies demonstrated that E-cadherin is closely associated with claudin-1 (CLDN1) and occludin (OCLN) on the cell membrane. Depletion of E-cadherin drastically diminished the cell-surface distribution of these two tight junction proteins in various hepatic cell lines, indicating that E-cadherin plays an important regulatory role in CLDN1/OCLN localization on the cell surface. Furthermore, loss of E-cadherin expression in hepatocytes is associated with HCV-induced epithelial-to-mesenchymal transition (EMT), providing an important link between HCV infection and liver cancer. Our data indicate that a dynamic interplay among E-cadherin, tight junctions, and EMT exists and mediates an important function in HCV entry. PMID:27298373

  18. Loss of E-cadherin expression is not a prerequisite for c-erbB2-induced epithelial-mesenchymal transition

    PubMed Central

    NILSSON, GISELA M.A.; AKHTAR, NOREEN; KANNIUS-JANSON, MARIE; BAECKSTRÖM, DAN

    2014-01-01

    Recent research into the mechanisms of tumour cell invasiveness has highlighted the parallels between carcinogenesis and epithelial-mesenchymal transition (EMT), originally described as a developmental transdifferentiation program but also implicated in fibrosis and cancer. In a model system for mammary carcinogenesis, we previously observed that induced signalling from a homodimer of the c-erbB2 (HER2) receptor tyrosine kinase in an initially non-malignant mammary cell line caused EMT where i) cell scattering occurred before downregulation of the cell-cell adhesion molecule E-cadherin and ii) the progress of EMT was dramatically delayed when cells were grown at high density. Here, we have further analysed these phenomena. Ectopic expression of E-cadherin concomitant with c-erbB2 signalling was unable to impede the progression of EMT, suggesting that E-cadherin downregulation is not required for EMT. Furthermore, fibroblast-like cells isolated after EMT induced in the presence or absence of ectopic E-cadherin expression showed highly similar morphology and vimentin expression. E-cadherin expressed in these fibroblastic cells had a subcellular localisation similar to that found in epithelial cells, but it exhibited a much weaker attachment to the cytoskeleton, suggesting cytoskeletal rearrangements as an important mechanism in EMT-associated cell scattering. We also investigated whether density-dependent inhibition of EMT is mediated by E-cadherin as a sensor for cell-cell contact, by expressing dominant-negative E-cadherin. While expression of this mutant weakened cell-cell adhesion, it failed to facilitate EMT at high cell densities. These results indicate that loss of E-cadherin expression is a consequence rather than a cause of c-erbB2-induced EMT and that density-dependent inhibition of EMT is not mediated by E-cadherin signalling. PMID:24807161

  19. Cadherin binding is not a limiting step for Bacillus thuringiensis subsp. israelensis Cry4Ba toxicity to Aedes aegypti larvae.

    PubMed

    Rodríguez-Almazán, Claudia; Reyes, Esmeralda Z; Zúñiga-Navarrete, Fernando; Muñoz-Garay, Carlos; Gómez, Isabel; Evans, Amy M; Likitvivatanavong, Supaporn; Bravo, Alejandra; Gill, Sarjeet S; Soberón, Mario

    2012-05-01

    Bacillus thuringiensis subsp. israelensis produces three Cry toxins (Cry4Aa, Cry4Ba and Cry11Aa) that are active against Aedes aegypti larvae. The identification of the rate-limiting binding steps of Cry toxins that are used for insect control in the field, such as those of B. thuringiensis subsp. israelensis, should provide targets for improving insecticides against important insect pests. Previous studies showed that Cry11Aa binds to cadherin receptor fragment CR7-11 (cadherin repeats 7-11) with high affinity. Binding to cadherin has been proposed to facilitate Cry toxin oligomer formation. In the present study, we show that Cry4Ba binds to CR7-11 with 9-fold lower binding affinity compared with Cry11Aa. Oligomerization assays showed that Cry4Ba is capable of forming oligomers when proteolytically activated in vitro in the absence of the CR7-11 fragment in contrast with Cry11Aa that formed oligomers only in the presence of CR7-11. Pore-formation assays in planar lipid bilayers showed that Cry4Ba oligomers were proficient in opening ion channels. Finally, silencing the cadherin gene by dsRNA (double-stranded RNA) showed that silenced larvae were more tolerant to Cry11Aa in contrast with Cry4Ba, which showed similar toxic levels to those of control larvae. These findings show that cadherin binding is not a limiting step for Cry4Ba toxicity to A. aegypti larvae. PMID:22329749

  20. Cadherin binding is not a limiting step for Bacillus thuringiensis subsp. israelensis Cry4Ba toxicity to Aedes aegypti larvae

    PubMed Central

    Rodríguez-Almazán, Claudia; Reyes, Esmeralda Z.; Zúñiga-Navarrete, Fernando; Muñoz-Garay, Carlos; Gómez, Isabel; Evans, Amy M.; Likitvivatanavong, Supaporn; Bravo, Alejandra; Gill, Sarjeet S.; Soberón, Mario

    2013-01-01

    Bacillus thuringiensis subsp. israelensis produces three Cry toxins (Cry4Aa, Cry4Ba and Cry11Aa) that are active against Aedes aegypti larvae. The identification of the rate-limiting binding steps of Cry toxins that are used for insect control in the field, such as those of B. thuringiensis subsp. israelensis, should provide targets for improving insecticides against important insect pests. Previous studies showed that Cry11Aa binds to cadherin receptor fragment CR7–11 (cadherin repeats 7–11) with high affinity. Binding to cadherin has been proposed to facilitate Cry toxin oligomer formation. In the present study, we show that Cry4Ba binds to CR7–11 with 9-fold lower binding affinity compared with Cry11Aa. Oligomerization assays showed that Cry4Ba is capable of forming oligomers when proteolytically activated in vitro in the absence of the CR7–11 fragment in contrast with Cry11Aa that formed oligomers only in the presence of CR7–11. Pore-formation assays in planar lipid bilayers showed that Cry4Ba oligomers were proficient in opening ion channels. Finally, silencing the cadherin gene by dsRNA (double-stranded RNA) showed that silenced larvae were more tolerant to Cry11Aa in contrast with Cry4Ba, which showed similar toxic levels to those of control larvae. These findings show that cadherin binding is not a limiting step for Cry4Ba toxicity to A. aegypti larvae. PMID:22329749

  1. Regulation of cadherin expression in nervous system development

    PubMed Central

    Paulson, Alicia F; Prasad, Maneeshi S; Thuringer, Amanda Henke; Manzerra, Pasquale

    2014-01-01

    This review addresses our current understanding of the regulatory mechanisms for classical cadherin expression during development of the vertebrate nervous system. The complexity of the spatial and temporal expression patterns is linked to morphogenic and functional roles in the developing nervous system. While the regulatory networks controlling cadherin expression are not well understood, it is likely that the multiple signaling pathways active in the development of particular domains also regulate the specific cadherins expressed at that time and location. With the growing understanding of the broader roles of cadherins in cell–cell adhesion and non-adhesion processes, it is important to understand both the upstream regulation of cadherin expression and the downstream effects of specific cadherins within their cellular context. PMID:24526207

  2. Atypical cadherins Celsr1-3 and planar cell polarity in vertebrates.

    PubMed

    Tissir, Fadel; Goffinet, André M

    2013-01-01

    Cadherin EGF LAG seven-pass G-type receptors 1, 2, and 3 (Celsr1-3) form a family of three atypical cadherins with multiple functions in epithelia and in the nervous system. During the past decade, evidence has accumulated for important and distinct roles of Celsr1-3 in planar cell polarity (PCP) during the development of the brain and some other organs. Although Celsr function in PCP is conserved from flies to mammals, other functions may be more distantly related, with Celsr working only with one or a subset of the classical core PCP partners. Here, we review the literature on Celsr, focusing on PCP and particularly on brain development. PMID:23481196

  3. E-Cadherin and Gastric Cancer: Cause, Consequence, and Applications

    PubMed Central

    Liu, Xin

    2014-01-01

    E-cadherin (epithelial-cadherin), encoded by the CDH1 gene, is a transmembrane glycoprotein playing a crucial role in maintaining cell-cell adhesion. E-cadherin has been reported to be a tumor suppressor and to be down regulated in gastric cancer. Besides genetic mutations in CDH1 gene to induce hereditary diffuse gastric cancer (HDGC), epigenetic factors such as DNA hypermethylation also contribute to the reduction of E-cadherin in gastric carcinogenesis. In addition, expression of E-cadherin could be mediated by infectious agents such as H. pylori (Helicobacter pylori). As E-cadherin is vitally involved in signaling pathways modulating cell proliferation, survival, invasion, and migration, dysregulation of E-cadherin leads to dysfunction of gastric epithelial cells and contributes to gastric cancer development. Moreover, changes in its expression could reflect pathological conditions of gastric mucosa, making its role in gastric cancer complicated. In this review, we summarize the functions of E-cadherin and the signaling pathways it regulates. We aim to provide comprehensive perspectives in the molecular mechanism of E-cadherin and its involvement in gastric cancer initiation and progression. We also focus on its applications for early diagnosis, prognosis, and therapy in gastric cancer in order to open new avenues in this field. PMID:25184143

  4. Genome-wide identification, characterization of sugar transporter genes in the silkworm Bombyx mori and role in Bombyx mori nucleopolyhedrovirus (BmNPV) infection.

    PubMed

    Govindaraj, Lekha; Gupta, Tania; Esvaran, Vijaya Gowri; Awasthi, Arvind Kumar; Ponnuvel, Kangayam M

    2016-04-01

    Sugar transporters play an essential role in controlling carbohydrate transport and are responsible for mediating the movement of sugars into cells. These genes exist as large multigene families within the insect genome. In insects, sugar transporters not only have a role in sugar transport, but may also act as receptors for virus entry. Genome-wide annotation of silkworm Bombyx mori (B. mori) revealed 100 putative sugar transporter (BmST) genes exists as a large multigene family and were classified into 11 sub families, through phylogenetic analysis. Chromosomes 27, 26 and 20 were found to possess the highest number of BmST paralogous genes, harboring 22, 7 and 6 genes, respectively. These genes occurred in clusters exhibiting the phenomenon of tandem gene duplication. The ovary, silk gland, hemocytes, midgut and malphigian tubules were the different tissues/cells enriched with BmST gene expression. The BmST gene BGIBMGA001498 had maximum EST transcripts of 134 and expressed exclusively in the malphigian tubule. The expression of EST transcripts of the BmST clustered genes on chromosome 27 was distributed in various tissues like testis, ovary, silk gland, malphigian tubule, maxillary galea, prothoracic gland, epidermis, fat body and midgut. Three sugar transporter genes (BmST) were constitutively expressed in the susceptible race and were down regulated upon BmNPV infection at 12h post infection (hpi). The expression pattern of these three genes was validated through real-time PCR in the midgut tissues at different time intervals from 0 to 30hpi. In the susceptible B. mori race, expression of sugar transporter genes was constitutively expressed making the host succumb to viral infection. PMID:26743125

  5. MORIS: Visible-NIR Instrument Integration at the IRTF

    NASA Astrophysics Data System (ADS)

    Bus, S. J.; Gulbis, A. A. S.; Elliot, J. L.; Denault, A. J.; Rayner, J. T.; Stahlberger, W. E.; Chung, R.; Tokunaga, A. T.

    2011-10-01

    NASA's 3-m Infrared Telescope Facility (IRTF) on Mauna Kea, HI plays a leading role in obtaining ground-based Solar System observations. MORIS (the MIT Optical Rapid Imaging System [1]) was developed to provide high-speed optical imaging capabilities, primarily for stellar occultations and extrasolar planetary transits. To expand the IRTF's capabilities for planetary observations, we have upgraded the MORIS system to significantly improve its photometric capabilities and image quality. Further, we have developed integrated software to allow simultaneous operation of MORIS with SpeX, the low- to mid-resolution near-infrared (NIR) spectrograph and imager [2].

  6. Targeted Mutagenesis in Bombyx mori Using TALENs.

    PubMed

    Takasu, Yoko; Tamura, Toshiki; Goldsmith, Marian; Zurovec, Michal

    2016-01-01

    Bombyx mori is a valuable model organism of high economic importance. Its genome sequence is available, as well as basic genetic and molecular genetic tools and markers. The introduction of genome editing methods based on engineered nucleases enables precise manipulations with genomic DNA, including targeted DNA deletions, insertions, or replacements in the genome allowing gene analysis and various applications. We describe here the use of TALENs which have a simple modular design of their DNA-binding domains, are easy to prepare and proved to be efficient in targeting of a wide range of cleavage sites. Our procedure often allows the production of individuals carrying homozygous mutations as early as in the G1 generation. PMID:26443219

  7. Genomic diversity of Bombyx mori nucleopolyhedrovirus strains.

    PubMed

    Xu, Yi-Peng; Cheng, Ruo-Lin; Xi, Yu; Zhang, Chuan-Xi

    2013-07-01

    Bombyx mori nucleopolyhedrovirus (BmNPV) is a baculovirus that selectively infects the domestic silkworm. In this study, six BmNPV strains were compared at the whole genome level. We found that the number of bro genes and the composition of the homologous regions (hrs) are the two primary areas of divergence within these genomes. When we compared the ORFs of these BmNPV variants, we noticed a high degree of sequence divergence in the ORFs that are not baculovirus core genes. This result is consistent with the results derived from phylogenetic trees and evolutionary pressure analyses of these ORFs, indicating that ORFs that are not core genes likely play important roles in the evolution of BmNPV strains. The evolutionary relationships of these BmNPV strains might be explained by their geographic origins or those of their hosts. In addition, the total number of hr palindromes seems to affect viral DNA replication in Bm5 cells. PMID:23639478

  8. Tobacco plants expressing the Cry1AbMod toxin suppress tolerance to Cry1Ab toxin of Manduca sexta cadherin-silenced larvae.

    PubMed

    Porta, Helena; Jiménez, Gladys; Cordoba, Elizabeth; León, Patricia; Soberón, Mario; Bravo, Alejandra

    2011-07-01

    Cry toxins produced by Bacillus thuringiensis bacteria are insecticidal proteins used worldwide in the control of different insect pests. Alterations in toxin-receptor interaction represent the most common mechanism to induce resistance to Cry toxins in lepidopteran insects. Cry toxins bind with high affinity to the cadherin protein present in the midgut cells and this interaction facilitates the proteolytic removal of helix α-1 and pre-pore oligomer formation. Resistance to Cry toxins has been linked with mutations in the cadherin gene. One strategy effective to overcome larval resistance to Cry1A toxins is the production of Cry1AMod toxins that lack helix α-1. Cry1AMod are able to form oligomeric structures without binding to cadherin receptor and were shown to be toxic to cadherin-silenced Manduca sexta larvae and Pectinophora gossypiella strain with resistance linked to mutations in a cadherin gene. We developed Cry1AbMod tobacco transgenic plants to analyze if Cry1AMod toxins can be expressed in transgenic crops, do not affect plant development and are able to control insect pests. Our results show that production of the Cry1AbMod toxin in transgenic plants does not affect plant development, since these plants exhibited healthy growth, produced abundant seeds, and were virtually undistinguishable from control plants. Most importantly, Cry1AbMod protein produced in tobacco plants retains its functional toxic activity against susceptible and tolerant M. sexta larvae due to the silencing of cadherin receptor by RNAi. These results suggest that CryMod toxins could potentially be expressed in other transgenic crops to protect them against both toxin-susceptible and resistant lepidopteran larvae affected in cadherin gene. PMID:21621616

  9. Crystal Structure of Human E-Cadherin-EC1EC2 in Complex with a Peptidomimetic Competitive Inhibitor of Cadherin Homophilic Interaction.

    PubMed

    Nardone, Valentina; Lucarelli, Anna Paola; Dalle Vedove, Andrea; Fanelli, Roberto; Tomassetti, Antonella; Belvisi, Laura; Civera, Monica; Parisini, Emilio

    2016-05-26

    Cadherins are transmembrane cell adhesion proteins whose aberrant expression often correlates with cancer development and proliferation. We report the crystal structure of an E-cadherin extracellular fragment in complex with a peptidomimetic compound that was previously shown to partially inhibit cadherin homophilic adhesion. The structure reveals an unexpected binding mode and allows the identification of a druggable cadherin interface, thus paving the way to a future structure-guided design of cell adhesion inhibitors against cadherin-expressing solid tumors. PMID:27120112

  10. Structural Determinants of Cadherin-23 Function in Hearing and Deafness

    SciTech Connect

    Sotomayor, Marcos; Weihofen, Wilhelm A.; Gaudet, Rachelle; Corey, David P.

    2010-06-21

    The hair-cell tip link, a fine filament directly conveying force to mechanosensitive transduction channels, is composed of two proteins, protocadherin-15 and cadherin-23, whose mutation causes deafness. However, their molecular structure, elasticity, and deafness-related structural defects are unknown. We present crystal structures of the first and second extracellular cadherin repeats of cadherin-23. Overall, structures show typical cadherin folds, but reveal an elongated N terminus that precludes classical cadherin interactions and contributes to an N-terminal Ca{sup 2+}-binding site. The deafness mutation D101G, in the linker region between the repeats, causes a slight bend between repeats and decreases Ca{sup 2+} affinity. Molecular dynamics simulations suggest that cadherin-23 repeats are stiff and that either removing Ca{sup 2+} or mutating Ca{sup 2+}-binding residues reduces rigidity and unfolding strength. The structures define an uncharacterized cadherin family and, with simulations, suggest mechanisms underlying inherited deafness and how cadherin-23 may bind with itself and with protocadherin-15 to form the tip link.

  11. N-cadherin prodomain cleavage regulates synapse formation in vivo.

    PubMed

    Latefi, Nazlie S; Pedraza, Liliana; Schohl, Anne; Li, Ziwei; Ruthazer, Edward S

    2009-07-01

    Cadherins are initially synthesized bearing a prodomain that is thought to limit adhesion during early stages of biosynthesis. Functional cadherins lack this prodomain, raising the intriguing possibility that cells may utilize prodomain cleavage as a means to temporally or spatially regulate adhesion after delivery of cadherin to the cell surface. In support of this idea, immunostaining for the prodomain of zebrafish N-cadherin revealed enriched labeling at neuronal surfaces at the soma and along axonal processes. To determine whether post-translational cleavage of the prodomain affects synapse formation, we imaged Rohon-Beard cells in zebrafish embryos expressing GFP-tagged wild-type N-cadherin (NCAD-GFP) or a GFP-tagged N-cadherin mutant expressing an uncleavable prodomain (PRON-GFP) rendering it nonadhesive. NCAD-GFP accumulated at synaptic microdomains in a developmentally regulated manner, and its overexpression transiently accelerated synapse formation. PRON-GFP was much more diffusely distributed along the axon and its overexpression delayed synapse formation. Our results support the notion that N-cadherin serves to stabilize pre- to postsynaptic contacts early in synapse development and suggests that regulated cleavage of the N-cadherin prodomain may be a mechanism by which the kinetics of synaptogenesis are regulated. PMID:19365814

  12. ERβ1 inhibits the migration and invasion of breast cancer cells through upregulation of E-cadherin in a Id1-dependent manner

    SciTech Connect

    Zhou, Yan; Ming, Jia; Xu, Yan; Zhang, Yi; Jiang, Jun

    2015-02-06

    Highlights: • Expression of ERβ1 was positively correlated with E-cadherin in breast cancer cell. • ERβ1 upregulates E-cadherin expression in breast cancer cell lines. • ERβ1 upregulates E-cadherin expression in a Id1-dependent manner. - Abstract: ERβ1 is a member of the nuclear receptor superfamily of ligand-regulated transcription factors. It plays an important role in regulating the progression of breast cancer. However, the mechanisms of ERβ1 in tumorigenesis, metastasis and prognosis are still not fully clear. In this study, we showed that the expression of ERβ1 was positively correlated with E-cadherin expression in breast cancer cell lines. In addition, we found that ERβ1 upregulates E-cadherin expression in breast cancer cell lines. Furthermore, we also found that ERβ1 inhibits the migration and invasion of breast cancer cells and upregulated E-cadherin expression in a Id1-dependent manner. Taken together, our study provides further understanding of the molecular mechanism of ERβ1 in tumor metastasis and suggests the feasibility of developing novel therapeutic approaches to target Id1 to inhibit breast cancer metastasis.

  13. Expression of Tenascin C, EGFR, E-Cadherin, and TTF-1 in Medullary Thyroid Carcinoma and the Correlation with RET Mutation Status

    PubMed Central

    Steiner, Florian; Hauser-Kronberger, Cornelia; Rendl, Gundula; Rodrigues, Margarida; Pirich, Christian

    2016-01-01

    Tenascin C expression correlates with tumor grade and indicates worse prognosis in several tumors. Epidermal growth factor receptor (EGFR) plays an important role in driving proliferation in many tumors. Loss of E-cadherin function is associated with tumor invasion and metastasis. Thyroid transcription factor-1 (TTF-1) is involved in rearranged during transfection (RET) transcription in Hirschsprung’s disease. Tenascin C, EGFR, E-cadherin, TTF-1-expression, and their correlations with RET mutation status were investigated in 30 patients with medullary thyroid carcinoma (MTC) (n = 26) or C-cell hyperplasia (n = 4). Tenascin C was found in all, EGFR in 4/26, E-cadherin in 23/26, and TTF-1 in 25/26 MTC. Tenascin C correlated significantly with tumor proliferation (overall, r = 0.61, p < 0.005; RET-mutated, r = 0.81, p < 0.01). E-cadherin showed weak correlation, whereas EGFR and TTF-1 showed no significant correlation with tumor proliferation. EGFR, E-cadherin, and TTF-1 showed weak correlation with proliferation of RET-mutated tumors. Correlation between TTF-1 and tenascin C, E-cadherin, and EGFR was r = −0.10, 0.37, and 0.21, respectively. In conclusion, MTC express tenascin C, E-cadherin, and TTF-1. Tenascin C correlates significantly with tumor proliferation, especially in RET-mutated tumors. EGFR is low, and tumors expressing EGFR do not exhibit higher proliferation. TTF-1 does not correlate with RET mutation status and has a weak correlation with tenascin C, E-cadherin, and EGFR expression. PMID:27409604

  14. Expression of Tenascin C, EGFR, E-Cadherin, and TTF-1 in Medullary Thyroid Carcinoma and the Correlation with RET Mutation Status.

    PubMed

    Steiner, Florian; Hauser-Kronberger, Cornelia; Rendl, Gundula; Rodrigues, Margarida; Pirich, Christian

    2016-01-01

    Tenascin C expression correlates with tumor grade and indicates worse prognosis in several tumors. Epidermal growth factor receptor (EGFR) plays an important role in driving proliferation in many tumors. Loss of E-cadherin function is associated with tumor invasion and metastasis. Thyroid transcription factor-1 (TTF-1) is involved in rearranged during transfection (RET) transcription in Hirschsprung's disease. Tenascin C, EGFR, E-cadherin, TTF-1-expression, and their correlations with RET mutation status were investigated in 30 patients with medullary thyroid carcinoma (MTC) (n = 26) or C-cell hyperplasia (n = 4). Tenascin C was found in all, EGFR in 4/26, E-cadherin in 23/26, and TTF-1 in 25/26 MTC. Tenascin C correlated significantly with tumor proliferation (overall, r = 0.61, p < 0.005; RET-mutated, r = 0.81, p < 0.01). E-cadherin showed weak correlation, whereas EGFR and TTF-1 showed no significant correlation with tumor proliferation. EGFR, E-cadherin, and TTF-1 showed weak correlation with proliferation of RET-mutated tumors. Correlation between TTF-1 and tenascin C, E-cadherin, and EGFR was r = -0.10, 0.37, and 0.21, respectively. In conclusion, MTC express tenascin C, E-cadherin, and TTF-1. Tenascin C correlates significantly with tumor proliferation, especially in RET-mutated tumors. EGFR is low, and tumors expressing EGFR do not exhibit higher proliferation. TTF-1 does not correlate with RET mutation status and has a weak correlation with tenascin C, E-cadherin, and EGFR expression. PMID:27409604

  15. N-Cadherin Expression Is Associated with Acquisition of EMT Phenotype and with Enhanced Invasion in Erlotinib-Resistant Lung Cancer Cell Lines

    PubMed Central

    Zhang, Xiaoju; Liu, Guangzhi; Kang, Yi; Dong, Zhaogang; Qian, Qiyu; Ma, Xitao

    2013-01-01

    Background The epidermal growth-factor receptor tyrosine kinase inhibitors have been effective in non-small cell lung cancer patients. However, acquired resistance eventually develops in most patients despite an initial positive response. Emerging evidence suggests that there is a molecular connection between acquired resistance and the epithelial–mesenchymal transition (EMT). N-cadherin is involved in the EMT and in the metastasis of cancer cells. Here, we analyzed N-cadherin expression and function in erlotinib-resistant lung cancer cell lines. Methods H1650 cell lines were used to establish the subline resistant to erlotinib(H1650ER). Then, induction of the EMT was analyzed using immunostaining and western blots in H1650ER cells. N-cadherin expression in the resistant cells was examined using FACS and western blot. In addition, an invasion assay was performed to characterize the resistant cells. The effects of N-cadherin on cell proliferation and invasion were analyzed. The association of N-cadherin expression with the EMT phenotype was investigated using immunohistochemical analysis of 13 archived, lung adenocarcinoma tissues, before and after treatment with erlotinib. Results In H1650ER cells, N-cadherin expression was upregulated, paralleled by the reduced expression of E-cadherin. The marked histological change and the development of a spindle-like morphology suggest that H1650ER cells underwent an EMT, accompanied by a decrease in E-cadherin and an increase in vimentin. A change in the EMT status between pre-and post-treatment was observed in 11 out of 13 cases (79%). In biopsies of resistant cancers, N-cadherin expression was increased in 10 out of 13 cases. Induction of the EMT was consistent with aggressive characteristics. Inhibition of N-cadherin expression by siRNA was tested to reduce proliferation and invasion of H1650ER cells in vitro. Conclusions Our data provide evidence that induction of the EMT contributes to the acquired resistance to EGFR

  16. Recombinant fragilysin isoforms cause E-cadherin cleavage of intact cells and do not cleave isolated E-cadherin.

    PubMed

    Kharlampieva, Daria; Manuvera, Valentin; Podgorny, Oleg; Grafskaia, Ekaterina; Kovalchuk, Sergey; Pobeguts, Olga; Altukhov, Ilya; Govorun, Vadim; Lazarev, Vassili

    2015-01-01

    The fragilysin (BFT) is a protein secreted by enterotoxigenic Bacteroides fragilis strains. BFT contains zinc-binding motif which was found in the metzincins family of metalloproteinases. In this study, we generated three known recombinant isoforms of BFT using Escherichia coli, tested their activity and examined whether E-cadherin is a substrate for BFTs. BFT treatment of HT-29 cells induced endogenous E-cadherin cleavage, and this BFT activity requires the native structure of zinc-binding motif. At the same time recombinant BFTs did not cleave recombinant E-cadherin or E-cadherin in isolated cell fractions. It indicates that E-cadherin may be not direct substrate for BFT. We also detected and identified proteins released into the cultural medium after HT-29 cells treatment with BFT. The role of these proteins in pathogenesis and cell response to BFT remains to be determined. PMID:25998017

  17. Dipeptidyl Peptidase-4 Inhibitor Increases Vascular Leakage in Retina through VE-cadherin Phosphorylation.

    PubMed

    Lee, Choon-Soo; Kim, Yun Gi; Cho, Hyun-Jai; Park, Jonghanne; Jeong, Heewon; Lee, Sang-Eun; Lee, Seung-Pyo; Kang, Hyun-Jae; Kim, Hyo-Soo

    2016-01-01

    The inhibitors of CD26 (dipeptidyl peptidase-4; DPP4) have been widely prescribed to control glucose level in diabetic patients. DPP4-inhibitors, however, accumulate stromal cell-derived factor-1α (SDF-1α), a well-known inducer of vascular leakage and angiogenesis both of which are fundamental pathophysiology of diabetic retinopathy. The aim of this study was to investigate the effects of DPP4-inhibitors on vascular permeability and diabetic retinopathy. DPP4-inhibitor (diprotin A or sitagliptin) increased the phosphorylation of Src and vascular endothelial-cadherin (VE-cadherin) in human endothelial cells and disrupted endothelial cell-to-cell junctions, which were attenuated by CXCR4 (receptor of SDF-1α)-blocker or Src-inhibitor. Disruption of endothelial cell-to-cell junctions in the immuno-fluorescence images correlated with the actual leakage of the endothelial monolayer in the transwell endothelial permeability assay. In the Miles assay, vascular leakage was observed in the ears into which SDF-1α was injected, and this effect was aggravated by DPP4-inhibitor. In the model of retinopathy of prematurity, DPP4-inhibitor increased not only retinal vascularity but also leakage. Additionally, in the murine diabetic retinopathy model, DPP4-inhibitor increased the phosphorylation of Src and VE-cadherin and aggravated vascular leakage in the retinas. Collectively, DPP4-inhibitor induced vascular leakage by augmenting the SDF-1α/CXCR4/Src/VE-cadherin signaling pathway. These data highlight safety issues associated with the use of DPP4-inhibitors. PMID:27381080

  18. Phospholipase Cδ1 induces E-cadherin expression and suppresses malignancy in colorectal cancer cells

    PubMed Central

    Satow, Reiko; Hirano, Tamaki; Batori, Ryosuke; Nakamura, Tomomi; Murayama, Yumi; Fukami, Kiyoko

    2014-01-01

    Colorectal cancer (CRC) is one of the most common causes of cancer-related deaths worldwide, and Kirsten rat sarcoma viral oncogene homolog (KRAS) mutations in CRC predict the ineffectiveness of EGF receptor-targeted therapy. Previous transcriptional microarray analysis suggests the association between phospholipase Cδ1 (PLCδ1) expression and KRAS mutation status in CRC. However, both the roles and the regulatory mechanisms of PLCδ1 in CRC are not known. Here, we found that the expression of PLCδ1, one of the most basal PLCs, is down-regulated in CRC specimens compared with normal colon epithelium by immunohistochemistry. Furthermore, we examined the roles of PLCδ1 in CRC cell lines that harbor an activating KRAS mutation. Ectopic expression of PLCδ1 in CRC cells induced the expression of E-cadherin, whereas knockdown of PLCδ1 repressed the expression of E-cadherin. Moreover, the overexpression of PLCδ1 suppressed the expression of several mesenchymal genes and reduced cell motility, invasiveness, and in vivo tumorigenicity of SW620 CRC cells. We also showed that PLCδ1 expression is repressed by the KRAS/mitogen-activated protein kinase kinase (MEK) pathway. Furthermore, PLCδ1 suppressed the phosphorylation of extracellular signal-regulated kinase (ERK)1/2 through E-cadherin induction in CRC cells, suggesting the presence of a negative regulatory loop between KRAS/MEK/ERK signaling and PLCδ1. These data indicate that PLCδ1 has tumor-suppressive functions in CRC through E-cadherin induction and KRAS/MEK/ERK signal attenuation. PMID:25197077

  19. Dipeptidyl Peptidase-4 Inhibitor Increases Vascular Leakage in Retina through VE-cadherin Phosphorylation

    PubMed Central

    Lee, Choon-Soo; Kim, Yun Gi; Cho, Hyun-Jai; Park, Jonghanne; Jeong, Heewon; Lee, Sang-Eun; Lee, Seung-Pyo; Kang, Hyun-Jae; Kim, Hyo-Soo

    2016-01-01

    The inhibitors of CD26 (dipeptidyl peptidase-4; DPP4) have been widely prescribed to control glucose level in diabetic patients. DPP4-inhibitors, however, accumulate stromal cell-derived factor-1α (SDF-1α), a well-known inducer of vascular leakage and angiogenesis both of which are fundamental pathophysiology of diabetic retinopathy. The aim of this study was to investigate the effects of DPP4-inhibitors on vascular permeability and diabetic retinopathy. DPP4-inhibitor (diprotin A or sitagliptin) increased the phosphorylation of Src and vascular endothelial-cadherin (VE-cadherin) in human endothelial cells and disrupted endothelial cell-to-cell junctions, which were attenuated by CXCR4 (receptor of SDF-1α)-blocker or Src-inhibitor. Disruption of endothelial cell-to-cell junctions in the immuno-fluorescence images correlated with the actual leakage of the endothelial monolayer in the transwell endothelial permeability assay. In the Miles assay, vascular leakage was observed in the ears into which SDF-1α was injected, and this effect was aggravated by DPP4-inhibitor. In the model of retinopathy of prematurity, DPP4-inhibitor increased not only retinal vascularity but also leakage. Additionally, in the murine diabetic retinopathy model, DPP4-inhibitor increased the phosphorylation of Src and VE-cadherin and aggravated vascular leakage in the retinas. Collectively, DPP4-inhibitor induced vascular leakage by augmenting the SDF-1α/CXCR4/Src/VE-cadherin signaling pathway. These data highlight safety issues associated with the use of DPP4-inhibitors. PMID:27381080

  20. Crossroads of integrins and cadherins in epithelia and stroma remodeling.

    PubMed

    Epifano, Carolina; Perez-Moreno, Mirna

    2012-01-01

    Adhesion events mediated by cadherin and integrin adhesion receptors have fundamental roles in the maintenance of the physiological balance of epithelial tissues, and it is well established that perturbations in their normal functional activity and/or changes in their expression are associated with tumorigenesis. Over the last decades, increasing evidence of a dynamic collaborative interaction between these complexes through their shared interactions with cytoskeletal proteins and common signaling pathways has emerged not only as an important regulator of several aspects of epithelial cell behavior, but also as a coordinated adhesion module that senses and transmits signals from and to the epithelia surrounding microenvironment. The tight regulation of their crosstalk is particularly important during epithelial remodeling events that normally take place during morphogenesis and tissue repair, and when defective it leads to cell transformation and aggravated responses of the tumor microenvironment that contribute to tumorigenesis. In this review we highlight some of the interactions that regulate their crosstalk and how this could be implicated in regulating signals across epithelial tissues to sustain homeostasis. PMID:22568988

  1. Mechanosensitive systems at the cadherin-F-actin interface.

    PubMed

    Huveneers, Stephan; de Rooij, Johan

    2013-01-15

    Cells integrate biochemical and mechanical information to function within multicellular tissue. Within developing and remodeling tissues, mechanical forces contain instructive information that governs important cellular processes that include stem cell maintenance, differentiation and growth. Although the principles of signal transduction (protein phosphorylation, allosteric regulation of enzymatic activity and binding sites) are the same for biochemical and mechanical-induced signaling, the first step of mechanosensing, in which protein complexes under tension transduce changes in physical force into cellular signaling, is very different, and the molecular mechanisms are only beginning to be elucidated. In this Commentary, we focus on mechanotransduction at cell-cell junctions, aiming to comprehend the molecular mechanisms involved. We describe how different junction structures are associated with the actomyosin cytoskeleton and how this relates to the magnitude and direction of forces at cell-cell junctions. We discuss which cell-cell adhesion receptors have been shown to take part in mechanotransduction. Then we outline the force-induced molecular events that might occur within a key mechanosensitive system at cell-cell junctions; the cadherin-F-actin interface, at which α-catenin and vinculin form a central module. Mechanotransduction at cell-cell junctions emerges as an important signaling mechanism, and we present examples of its potential relevance for tissue development and disease. PMID:23524998

  2. Identification of new human cadherin genes using a combination of protein motif search and gene finding methods.

    PubMed

    Hoeng, Julia C; Höng, Julia C; Ivanov, Nikolai V; Hodor, Paul; Xia, Menghang; Wei, Nan; Blevins, Richard; Gerhold, David; Borodovsky, Mark; Liu, Yuan

    2004-03-19

    We have combined protein motif search and gene finding methods to identify genes encoding proteins containing specific domains. Particularly, we have focused on finding new human genes of the cadherin superfamily proteins, which represent a major group of cell-cell adhesion receptors contributing to embryonic neuronal morphogenesis. Models for three cadherin protein motifs were generated from over 100 already annotated cadherin domains and used to search the complete translated human genome. The genomic sequence regions containing motif "hits" were analyzed by eukaryotic GeneMark.hmm to identify the exon-intron structure of new genes. Three new genes CDH-J, PCDH-J and FAT-J were found. The predicted proteins PCDH-J and FAT-J were classified into protocadherin and FAT-like subfamilies, respectively, based on the number and organization of cadherin domains and presence of subfamily-specific conserved amino acid residues. Expression of FAT-J was shown in almost all tested tissues. The exon-intron organization of CDH-J was experimentally verified by PCR with specifically designed primers and its tissue-specific expression was demonstrated. The described methodology can be applied to discover new genes encoding proteins from families with well-characterized structural and functional domains. PMID:15003449

  3. Interfering with VE-PTP stabilizes endothelial junctions in vivo via Tie-2 in the absence of VE-cadherin.

    PubMed

    Frye, Maike; Dierkes, Martina; Küppers, Verena; Vockel, Matthias; Tomm, Janina; Zeuschner, Dagmar; Rossaint, Jan; Zarbock, Alexander; Koh, Gou Young; Peters, Kevin; Nottebaum, Astrid Fee; Vestweber, Dietmar

    2015-12-14

    Vascular endothelial (VE)-protein tyrosine phosphatase (PTP) associates with VE-cadherin, thereby supporting its adhesive activity and endothelial junction integrity. VE-PTP also associates with Tie-2, dampening the tyrosine kinase activity of this receptor that can support stabilization of endothelial junctions. Here, we have analyzed how interference with VE-PTP affects the stability of endothelial junctions in vivo. Blocking VE-PTP by antibodies, a specific pharmacological inhibitor (AKB-9778), and gene ablation counteracted vascular leak induction by inflammatory mediators. In addition, leukocyte transmigration through the endothelial barrier was attenuated. Interference with Tie-2 expression in vivo reversed junction-stabilizing effects of AKB-9778 into junction-destabilizing effects. Furthermore, lack of Tie-2 was sufficient to weaken the vessel barrier. Mechanistically, inhibition of VE-PTP stabilized endothelial junctions via Tie-2, which triggered activation of Rap1, which then caused the dissolution of radial stress fibers via Rac1 and suppression of nonmuscle myosin II. Remarkably, VE-cadherin gene ablation did not abolish the junction-stabilizing effect of the VE-PTP inhibitor. Collectively, we conclude that inhibition of VE-PTP stabilizes challenged endothelial junctions in vivo via Tie-2 by a VE-cadherin-independent mechanism. In the absence of Tie-2, however, VE-PTP inhibition destabilizes endothelial barrier integrity in agreement with the VE-cadherin-supportive effect of VE-PTP. PMID:26642851

  4. Cleavage of E-cadherin by ADAM10 mediates epithelial cell sorting downstream of EphB signalling.

    PubMed

    Solanas, Guiomar; Cortina, Carme; Sevillano, Marta; Batlle, Eduard

    2011-09-01

    The formation and maintenance of complex organs requires segregation of distinct cell populations into defined territories (that is, cell sorting) and the establishment of boundaries between them. Here we have investigated the mechanism by which Eph/ephrin signalling controls the compartmentalization of cells in epithelial tissues. We show that EphB/ephrin-B signalling in epithelial cells regulates the formation of E-cadherin-based adhesions. EphB receptors interact with E-cadherin and with the metalloproteinase ADAM10 at sites of adhesion and their activation induces shedding of E-cadherin by ADAM10 at interfaces with ephrin-B1-expressing cells. This process results in asymmetric localization of E-cadherin and, as a consequence, in differences in cell affinity between EphB-positive and ephrin-B-positive cells. Furthermore, genetic inhibition of ADAM10 activity in the intestine of mice results in a lack of compartmentalization of Paneth cells within the crypt stem cell niche, a defect that phenocopies that of EphB3-null mice. These results provide important insights into the regulation of cell migration in the intestinal epithelium and may help in the understanding of the nature of the cell sorting process in other epithelial tissues where Eph-ephrin interactions play a central role. PMID:21804545

  5. Detection of T-Cadherin Expression in Mouse Embryos

    PubMed Central

    Rubina, K. A.; Smutova, V. A.; Semenova, M. L.; Poliakov, A. A.; Gerety, S.; Wilkinson, D.; Surkova, E. I.; Semina, E. V.; Sysoeva, V. Yu.; Tkachuk, V. A.

    2015-01-01

    The aim of the present study was to evaluate T-cadherin expression at the early developmental stages of the mouse embryo. Using in situ hybridization and immunofluorescent staining of whole embryos in combination with confocal microscopy, we found that T-cadherin expression is detected in the developing brain, starting with the E8.75 stage, and in the heart, starting with the E11.5 stage. These data suggest a possible involvement of T-cadherin in the formation of blood vessels during embryogenesis. PMID:26085949

  6. Connections between cadherin-catenin proteins, spindle misorientation, and cancer

    PubMed Central

    Shahbazi, Marta N; Perez-Moreno, Mirna

    2015-01-01

    Cadherin-catenin mediated adhesion is an important determinant of tissue architecture in multicellular organisms. Cancer progression and maintenance is frequently associated with loss of their expression or functional activity, which not only leads to decreased cell-cell adhesion, but also to enhanced tumor cell proliferation and loss of differentiated characteristics. This review is focused on the emerging implications of cadherin-catenin proteins in the regulation of polarized divisions through their connections with the centrosomes, cytoskeleton, tissue tension and signaling pathways; and illustrates how alterations in cadherin-catenin levels or functional activity may render cells susceptible to transformation through the loss of their proliferation-differentiation balance. PMID:26451345

  7. Mechanisms of nodule-specific melanization in the hemocoel of the silkworm, Bombyx mori.

    PubMed

    Shu, Min; Mang, Dingze; Fu, Gege Sun; Tanaka, Shiho; Endo, Haruka; Kikuta, Shingo; Sato, Ryoichi

    2016-03-01

    In the insect immune system, nodules are known to be a product of the cellular response against microorganisms and may be a preferential target for melanization. However, the mechanism of nodule-preferential melanization remains to be explored. In this study, we identified several mechanisms of nodule-preferential melanization by analyzing congregation and the activation of several factors involved in the prophenoloxidase (proPO)-activating system in the silkworm, Bombyx mori. Microorganism-binding assays revealed that B. mori larval plasma have an effective invading microorganism-surveillance network consisting of at least six pattern-recognition receptors (PRRs). We also found that a hemolymph serine proteinase, BmHP14, can bind to Saccharomyces cerevisiae. Pull-down assays showed that PRR C-type lectins form protein complexes with serine proteinase homologs, BmSPH1 and BmSPH2, which leads to the activated forms of BmSPH1 and BmSPH2 being gathered on microorganisms and trapped in nodules. Immunostaining analysis revealed that most factors in the proPO-activating system and some factors in the triggering system for antimicrobial peptide production exist in the granules of hemocytes which can gather in nodules. Western blot analysis showed that factors in the proPO-activating system are congregated in formed nodules by their concentration in plasma and aggregating hemocytes. PMID:26707571

  8. Characterizing the initial encounter complex in cadherin adhesion

    PubMed Central

    Sivasankar, Sanjeevi; Zhang, Yunxiang; Nelson, W. James; Chu, Steven

    2009-01-01

    Summary Cadherins are Ca2+-dependent cell-cell adhesion proteins with an extracellular region of five domains (EC1 to EC5). Adhesion is mediated by “strand-swapping” of a conserved tryptophan residue in position 2 between EC1 domains of opposing cadherins, but the formation of this structure is not well understood. Using single molecule Fluorescence Resonance Energy Transfer (FRET) and single molecule force measurements with the Atomic Force Microscope (AFM), we demonstrate that cadherins initially interact via EC1 domains without swapping tryptophan-2 to form a weak Ca2+ dependent initial encounter complex that has 25% of the bond strength of a strand-swapped dimer. We suggest that cadherin dimerization proceeds via an induced fit mechanism where the monomers first form a tryptophan-2 independent initial encounter complex and then undergo subsequent conformational changes to form the final strand-swapped dimer. PMID:19646884

  9. Re-evaluation of the PBAN receptor molecule: characterization of PBANR variants expressed in the pheromone glands of moths

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Sex pheromone production in most moths is initiated following pheromone biosynthesis activating neuropeptide receptor (PBANR) activation. PBANR was initially cloned from pheromone glands (PGs) of Helicoverpa zea and Bombyx mori. The B. mori PBANR is characterized by a relatively long C-terminus that...

  10. LI-cadherin: a marker of gastric metaplasia and neoplasia

    PubMed Central

    Grotzinger, C; Kneifel, J; Patschan, D; Schnoy, N; Anagnostopoulos, I; Faiss, S; Tauber, R; Wiedenmann, B; Gessner, R

    2001-01-01

    BACKGROUND—Intestinal metaplasia is considered a risk factor for the development of gastric adenocarcinomas of the intestinal type and is found in approximately 20% of gastric biopsies. Conventional histology only detects advanced stages of intestinal metaplasia.
AIMS—To study expression of the enterocyte specific adhesion molecule liver-intestinal (LI)-cadherin in intestinal metaplasia as well as in gastric cancer, and to evaluate its use as a diagnostic marker molecule.
PATIENTS—Gastric biopsies (n=77) from 30 consecutive patients (n=30; aged 28-90 years) as well as surgically resected tissue samples (n=24) of all types of gastric carcinomas were analysed.
METHODS—Single and double label immunofluorescence detection on cryosections of gastric biopsies; alkaline phosphatase antialkaline phosphatase method on paraffin embedded carcinoma tissue sections.
RESULTS—Of 77 biopsies (from 30 patients), 12 (from 10 patients) stained positive for LI-cadherin. LI-cadherin staining correlated with the presence of intestinal metaplasia. Conventional histological diagnosis however failed to detect subtle gastric intestinal metaplasia (three of 10 patients). In contrast, only LI-cadherin and villin were positive in these cases whereas sucrase-isomaltase also failed to detect intestinal metaplasia in four of 10 patients. Well differentiated gastric carcinomas showed intense staining for LI-cadherin while undifferentiated carcinomas showed only weak diffuse cytoplasmic staining.
CONCLUSIONS—To detect early metaplastic changes in the gastric mucosa, LI-cadherin has a sensitivity superior to sucrase-isomaltase and conventional histology and comparable with that of villin. Its specificity exceeds that of villin. Thus LI-cadherin represents a new, reliable, and powerful marker molecule for early detection of gastric intestinal metaplasia and well differentiated adenocarcinomas.


Keywords: stomach; intestinal metaplasia; cadherins; carcinogenesis

  11. Segregation of European corn borer, Ostrinia nubilalis, aminopeptidase 1, cadherin, and bre5-like alleles, from a colony resistant to Bacillus thuringiensis Cry1Ab toxins, are not associated ...fed a diet containing Cry1Ab

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Peptide receptors may be required for activated Bacillus thuringiensis (Bt) Cry toxins to bind midgut epithelium prior to pore formation. Single nucleotide polymorphism (SNP) markers from two Ostrinia nubilalis midgut peptide receptors, cadherin (OnCad) and aminopeptidase N 1 (OnAPN1), and OnBre5 (...

  12. Epidermal growth factor down-regulates the expression of neutrophil gelatinase-associated lipocalin (NGAL) through E-cadherin in pancreatic cancer cells

    PubMed Central

    Tong, Zhimin; Chakraborty, Subhankar; Sung, Bokyung; Koolwal, Pooja; Kaur, Sukhwinder; Aggarwal, Bharat B.; Mani, Sendurai A.; Bresalier, Robert S.; Batra, Surinder K.; Guha, Sushovan

    2010-01-01

    BACKGROUND Our group previously reported that neutrophil gelatinase-associated lipocalin (NGAL) overexpression significantly blocked invasion and angiogenesis of pancreatic ductal adenocarcinoma (PDAC) and also demonstrated a loss of NGAL expression in the advanced stages of PDAC. However, little is known regarding mechanisms of NGAL regulation in PDAC. As EGF-EGFR axis is significantly upregulated in PDAC, we examined EGF-mediated NGAL regulation in these cells. METHODS NGAL-positive AsPC-1 and BxPC-3 cells were used as model system. Quantitative RT-PCR, western blot analysis, and immunofluorescence studies were used to investigate EGF-mediated effects on NGAL expression. E-cadherin expression was manipulated using lentiviral overexpression or shRNA constructs. NGAL promoter activity was assessed by luciferase-reporter assay and electrophoretic mobility shift assay (EMSA). RESULTS NGAL expression was positively associated with tumor differentiation and was significantly downregulated after EGF treatment along with a concomitant reduction of E-cadherin expression in PDAC cells. E-cadherin downregulation was partly through the EGF receptor (EGFR)-dependent MEK-ERK signaling pathway. In addition, E-cadherin downregulation reduced NGAL expression in PDAC cells, whereas overexpression of E-cadherin led to increased NGAL expression and partly rescued inhibition of NGAL expression by EGF. Furthermore, EGF in part through E-cadherin reduced NGAL promoter activity by blocking NF-κB activation. CONCLUSIONS We demonstrated for the first time that EGF potently blocked NGAL expression in PDAC cells. This effect is partly mediated through activation of the EGFR-MEK-ERK signaling pathway, which in turn downregulated E-cadherin with a subsequent reduction in NF-κB activation. Our findings illustrate a novel mechanism by which EGF regulates NGAL expression in PDAC. PMID:24048788

  13. Vangl2 Regulates E-Cadherin in Epithelial Cells

    PubMed Central

    Nagaoka, Tadahiro; Inutsuka, Ayumu; Begum, Khadiza; hafiz, Khandakar musabbir bin; Kishi, Masashi

    2014-01-01

    E-cadherin belongs to the classic cadherin subfamily of calcium-dependent cell adhesion molecules and is crucial for the formation and function of epithelial adherens junctions. In this study, we demonstrate that Vangl2, a vertebrate regulator of planar cell polarity (PCP), controls E-cadherin in epithelial cells. E-cadherin co-immunoprecipitates with Vangl2 from embryonic kidney extracts, and this association is also observed in transfected fibroblasts. Vangl2 enhances the internalization of E-cadherin when overexpressed. Conversely, the quantitative ratio of E-cadherin exposed to the cell surface is increased in cultured renal epithelial cells derived from Vangl2Lpt/+ mutant mice. Interestingly, Vangl2 is also internalized through protein traffic involving Rab5- and Dynamin-dependent endocytosis. Taken together with recent reports regarding the transport of Frizzled3, MMP14 and nephrin, these results suggest that one of the molecular functions of Vangl2 is to enhance the internalization of specific plasma membrane proteins with broad selectivity. This function may be involved in the control of intercellular PCP signalling or in the PCP-related rearrangement of cell adhesions. PMID:25373475

  14. Force via integrins but not E-cadherin decreases Oct3/4 expression in embryonic stem cells

    SciTech Connect

    Uda, Yuhei; Poh, Yeh-Chuin; Chowdhury, Farhan; Wu, Douglas C.; Tanaka, Tetsuya S.; Sato, Masaaki; Wang, Ning

    2011-11-18

    Highlights: Black-Right-Pointing-Pointer Force via integrins or cadherins induces similar cell stiffening responses. Black-Right-Pointing-Pointer Force via integrins but not cadherins induces cell spreading. Black-Right-Pointing-Pointer Force via integrins but not cadherins induces differentiation of embryonic stem cells. -- Abstract: Increasing evidence suggests that mechanical factors play a critical role in fate decisions of stem cells. Recently we have demonstrated that a local force applied via Arg-Gly-Asp (RGD) peptides coated magnetic beads to mouse embryonic stem (ES) cells increases cell spreading and cell stiffness and decreases Oct3/4 (Pou5f1) gene expression. However, it is not clear whether the effects of the applied stress on these functions of ES cells can be extended to natural extracellular matrix proteins or cell-cell adhesion molecules. Here we show that a local cyclic shear force applied via fibronectin or laminin to integrin receptors increased cell spreading and stiffness, downregulated Oct3/4 gene expression, and decreased cell proliferation rate. In contrast, the same cyclic force applied via cell-cell adhesion molecule E-cadherin (Cdh1) had no effects on cell spreading, Oct3/4 gene expression, and the self-renewal of mouse ES cells, but induced significant cell stiffening. Our findings demonstrate that biological responses of ES cells to force applied via integrins are different from those to force via E-cadherin, suggesting that mechanical forces might play different roles in different force transduction pathways to shape early embryogenesis.

  15. CRH suppressed TGFβ1-induced Epithelial-Mesenchymal Transition via induction of E-cadherin in breast cancer cells.

    PubMed

    Jin, Lai; Chen, Jiandong; Li, Li; Li, Chuanhua; Chen, Cheng; Li, Shengnan

    2014-04-01

    Since its discovery in biopsies from breast cancer patients, the effect of corticotropin-releasing hormone (CRH) on carcinoma progression is still unclear. Transforming growth factorβ1 (TGFβ1) promotes Epithelial-Mesenchymal Transition (EMT) and induces Snail1 and Twist1 expressions. Loss of epithelial cadherin (E-cadherin) mainly repressed by Snail1 and Twist1, has been considered as hallmark of Epithelial-Mesenchymal Transition (EMT). Two breast cancer cell lines, MCF-7 and MDA-MB-231 were used to investigate the effect of CRH on TGFβ1-induced EMT by transwell chamber. And HEK293 cells were transiently transfected with CRHR1 or CRHR2 to explore the definite effects of CRH receptor. We reported that CRH inhibited migration of human breast cancer cells through downregulation of Snail1 and Twist1, and subsequent upregulation of E-cadherin. CRH inhibited TGFβ1-mediated migration of MCF-7 via both CRHR1 and CRHR2 while this inhibition in MDA-MB-231 was mainly via CRHR2. Ectopic re-expression of CRHR1 or CRHR2 respectively in HEK293 cells increased E-cadherin expression after CRH stimulation. Furthermore, CRH repressed expression of mesenchymal marker, N-cadherin and induced expression of Occludin, inhibiting EMT in MCF-7 & MDA-MB-231. Our results suggest that CRH may function as a tumor suppressor, at least partly by regulating TGFβ1-mediated EMT. These results may contribute to uncovering the effect of CRH in breast tumorigenesis and progression. PMID:24412750

  16. cDNA cloning and expression of Bacillus thuringiensis Cry1Aa toxin binding 120 kDa aminopeptidase N from Bombyx mori.

    PubMed

    Yaoi, K; Nakanishi, K; Kadotani, T; Imamura, M; Koizumi, N; Iwahana, H; Sato, R

    1999-01-18

    Bacillus thuringiensis Cry1Aa toxin binds to a 120 kDa putative receptor protein in the Bombyx mori midgut. Recently, this protein was purified and identified as glycosyl-phosphatidylinositol (GPI) anchored aminopeptidase N (APN). In this study, a full-length cDNA thought to encode this 120 kDa APN was isolated and sequenced. It has a 2958 bp ORF encoding 986 amino acids. In the deduced amino acid sequence, we identified GPI-anchor and zinc-metallopeptidase signals, which are the same as those of APNs of other insects that are reported to be putative Cry1 toxin receptors. The B. mori APN amino acid sequence also has a high similarity with those of the other APNs. Subsequently, the recombinant APN was expressed by Escherichia coli and its Cry1Aa toxin binding ability was analyzed. Ligand blotting showed that Cry1Aa toxin bound to the recombinant APN. PMID:9931470

  17. Elevated Src family kinase activity stabilizes E-cadherin-based junctions and collective movement of head and neck squamous cell carcinomas

    PubMed Central

    Veracini, Laurence; Grall, Dominique; Schaub, Sébastien; Divonne, Stéphanie Beghelli-de la Forest; Etienne-Grimaldi, Marie-Christine; Milano, Gérard; Bozec, Alexandre; Babin, Emmanuel; Sudaka, Anne; Thariat, Juliette; Van Obberghen-Schilling, Ellen

    2015-01-01

    EGF receptor (EGFR) overexpression is thought to drive head and neck carcinogenesis however clinical responses to EGFR-targeting agents have been modest and alternate targets are actively sought to improve results. Src family kinases (SFKs), reported to act downstream of EGFR are among the alternative targets for which increased expression or activity in epithelial tumors is commonly associated to the dissolution of E-cadherin-based junctions and acquisition of a mesenchymal-like phenotype. Robust expression of total and activated Src was observed in advanced stage head and neck tumors (N=60) and in head and neck squamous cell carcinoma lines. In cultured cancer cells Src co-localized with E-cadherin in cell-cell junctions and its phosphorylation on Y419 was both constitutive and independent of EGFR activation. Selective inhibition of SFKs with SU6656 delocalized E-cadherin and disrupted cellular junctions without affecting E-cadherin expression and this effect was phenocopied by knockdown of Src or Yes. These findings reveal an EGFR-independent role for SFKs in the maintenance of intercellular junctions, which likely contributes to the cohesive invasion E-cadherin-positive cells in advanced tumors. Further, they highlight the need for a deeper comprehension of molecular pathways that drive collective cell invasion, in absence of mesenchymal transition, in order to combat tumor spread. PMID:25779657

  18. Elevated Src family kinase activity stabilizes E-cadherin-based junctions and collective movement of head and neck squamous cell carcinomas.

    PubMed

    Veracini, Laurence; Grall, Dominique; Schaub, Sébastien; Beghelli-de la Forest Divonne, Stéphanie; Etienne-Grimaldi, Marie-Christine; Milano, Gérard; Bozec, Alexandre; Babin, Emmanuel; Sudaka, Anne; Thariat, Juliette; Van Obberghen-Schilling, Ellen

    2015-04-10

    EGF receptor (EGFR) overexpression is thought to drive head and neck carcinogenesis however clinical responses to EGFR-targeting agents have been modest and alternate targets are actively sought to improve results. Src family kinases (SFKs), reported to act downstream of EGFR are among the alternative targets for which increased expression or activity in epithelial tumors is commonly associated to the dissolution of E-cadherin-based junctions and acquisition of a mesenchymal-like phenotype. Robust expression of total and activated Src was observed in advanced stage head and neck tumors (N=60) and in head and neck squamous cell carcinoma lines. In cultured cancer cells Src co-localized with E-cadherin in cell-cell junctions and its phosphorylation on Y419 was both constitutive and independent of EGFR activation. Selective inhibition of SFKs with SU6656 delocalized E-cadherin and disrupted cellular junctions without affecting E-cadherin expression and this effect was phenocopied by knockdown of Src or Yes. These findings reveal an EGFR-independent role for SFKs in the maintenance of intercellular junctions, which likely contributes to the cohesive invasion E-cadherin-positive cells in advanced tumors. Further, they highlight the need for a deeper comprehension of molecular pathways that drive collective cell invasion, in absence of mesenchymal transition, in order to combat tumor spread. PMID:25779657

  19. IL-8 suppresses E-cadherin expression in nasopharyngeal carcinoma cells by enhancing E-cadherin promoter DNA methylation.

    PubMed

    Zhang, Rui-Li; Peng, Li-Xia; Yang, Jun-Ping; Zheng, Li-Sheng; Xie, Ping; Wang, Meng-Yao; Huang, Bi-Jun; Zhao, Hua-Rong; Bao, Yong-Xing; Qian, Chao-Nan

    2016-01-01

    Nasopharyngeal carcinoma (NPC) has the highest metastasis potential among head and neck cancers. Distant metastasis is the major cause of treatment failure. Recent studies from our laboratory have revealed that IL-8 promotes NPC metastasis via activation of AKT signaling and induction of epithelial-mesenchymal transition (EMT) in the cells. In the present study, we found that IL-8 treatment for NPC cells resulted in an accumulation of DNMT1 protein through activating AKT1 pathway and consequent DNMT1 protein stabilization. Then DNMT1 suppressed E-cadherin expression by increasing the methylation of its promoter region. LY-294002 blocked IL-8-induced p-AKT1 activation resulting in reduction of DNMT1 and increase of E-cadherin expression, whereas forced demethylation using 5-aza-2'-deoxycytidine restored E-cadherin expression. In conclusion, our study, for the first time, shows that the IL-8/AKT1 signaling pathway stabilizes DNMT1 protein, consequently enhancing hypermethylation of E-cadherin promoter regions and downregulating E-cadherin protein level in NPC cells. Upon blockage of the IL-8/AKT pathway and inhibition of DNMT1, E-cadherin expression can be reversed. These data suggest that targeting the IL-8/AKT1 signaling pathway and DNMT1 may provide a potential therapeutic approach for blocking NPC metastasis. PMID:26530812

  20. Giant vesicles functionally expressing membrane receptors for an insect pheromone.

    PubMed

    Hamada, Satoshi; Tabuchi, Masashi; Toyota, Taro; Sakurai, Takeshi; Hosoi, Tomohiro; Nomoto, Tomonori; Nakatani, Kei; Fujinami, Masanori; Kanzaki, Ryohei

    2014-03-18

    To date, biochemical approaches to membrane receptors have been limited to the following methods: knockout or overexpression of membrane receptors by gene introduction and genome engineering or extraction of membrane receptor-surfactant complexes from innate cells and their introduction into model biomembranes. Here, we describe the development of a third method involving gene expression using cell-free in situ protein synthesis inside model biomembrane capsules. We verified this method by synthesizing olfactory receptors from the silkmoth Bombyx mori inside giant vesicles and found that they were excited in the presence of their ligand the Bombyx mori sex pheromone. PMID:24509495

  1. E-cadherin is required for cranial neural crest migration in Xenopus laevis.

    PubMed

    Huang, Chaolie; Kratzer, Marie-Claire; Wedlich, Doris; Kashef, Jubin

    2016-03-15

    The cranial neural crest (CNC) is a highly motile and multipotent embryonic cell population, which migrates directionally on defined routes throughout the embryo, contributing to facial structures including cartilage, bone and ganglia. Cadherin-mediated cell-cell adhesion is known to play a crucial role in the directional migration of CNC cells. However, migrating CNC co-express different cadherin subtypes, and their individual roles have yet to be fully explored. In previous studies, the expression of individual cadherin subtypes has been analysed using different methods with varying sensitivities, preventing the direct comparison of expression levels. Here, we provide the first comprehensive and comparative analysis of the expression of six cadherin superfamily members during different phases of CNC cell migration in Xenopus. By applying a quantitative RT-qPCR approach, we can determine the copy number and abundance of each expressed cadherin through different phases of CNC migration. Using this approach, we show for the first time expression of E-cadherin and XB/C-cadherin in CNC cells, adding them as two new members of cadherins co-expressed during CNC migration. Cadherin co-expression during CNC migration in Xenopus, in particular the constant expression of E-cadherin, contradicts the classical epithelial-mesenchymal transition (EMT) model postulating a switch in cadherin expression. Loss-of-function experiments further show that E-cadherin is required for proper CNC cell migration in vivo and also for cell protrusion formation in vitro. Knockdown of E-cadherin is not rescued by co-injection of other classical cadherins, pointing to a specific function of E-cadherin in mediating CNC cell migration. Finally, through reconstitution experiments with different E-cadherin deletion mutants in E-cadherin morphant embryos, we demonstrate that the extracellular domain, but not the cytoplasmic domain, of E-cadherin is sufficient to rescue CNC cell migration in vivo

  2. Identification of sumoylated proteins in the silkworm Bombyx mori.

    PubMed

    Tang, Xudong; Fu, Xuliang; Hao, Bifang; Zhu, Feng; Xiao, Shengyan; Xu, Li; Shen, Zhongyuan

    2014-01-01

    Small ubiquitin-like modifier (SUMO) modification (SUMOylation) is an important and widely used reversible modification system in eukaryotic cells. It regulates various cell processes, including protein targeting, transcriptional regulation, signal transduction, and cell division. To understand its role in the model lepidoptera insect Bombyx mori, a recombinant baculovirus was constructed to express an enhanced green fluorescent protein (eGFP)-SUMO fusion protein along with ubiquitin carrier protein 9 of Bombyx mori (BmUBC9). SUMOylation substrates from Bombyx mori cells infected with this baculovirus were isolated by immunoprecipitation and identified by LC-ESI-MS/MS. A total of 68 candidate SUMOylated proteins were identified, of which 59 proteins were functionally categorized to gene ontology (GO) terms. Analysis of kyoto encyclopedia of genes and genomes (KEGG) pathways showed that 46 of the identified proteins were involved in 76 pathways that mainly play a role in metabolism, spliceosome and ribosome functions, and in RNA transport. Furthermore, SUMOylation of four candidates (polyubiquitin-C-like isoform X1, 3-hydroxyacyl-CoA dehydrogenase, cyclin-related protein FAM58A-like and GTP-binding nuclear protein Ran) were verified by co-immunoprecipitation in Drosophila schneide 2 cells. In addition, 74% of the identified proteins were predicted to have at least one SUMOylation site. The data presented here shed light on the crucial process of protein sumoylation in Bombyx mori. PMID:25470021

  3. A Pathway for the Control of Anoikis Sensitivity by E-Cadherin and Epithelial-to-Mesenchymal Transition▿‡

    PubMed Central

    Kumar, Sanjeev; Park, Sun Hee; Cieply, Benjamin; Schupp, Jane; Killiam, Elizabeth; Zhang, Fan; Rimm, David L.; Frisch, Steven M.

    2011-01-01

    Detachment of epithelial cells from matrix or attachment to an inappropriate matrix engages an apoptotic response known as anoikis, which prevents metastasis. Cellular sensitivity to anoikis is compromised during the oncogenic epithelial-to-mesenchymal transition (EMT), through unknown mechanisms. We report here a pathway through which EMT confers anoikis resistance. NRAGE (neurotrophin receptor-interacting melanoma antigen) interacted with a component of the E-cadherin complex, ankyrin-G, maintaining NRAGE in the cytoplasm. Oncogenic EMT downregulated ankyrin-G, enhancing the nuclear localization of NRAGE. The oncogenic transcriptional repressor protein TBX2 interacted with NRAGE, repressing the tumor suppressor gene p14ARF. P14ARF sensitized cells to anoikis; conversely, the TBX2/NRAGE complex protected cells against anoikis by downregulating this gene. This represents a novel pathway for the regulation of anoikis by EMT and E-cadherin. PMID:21746881

  4. Characterization of the role of cadherin in regulating cell adhesion during sea urchin development.

    PubMed

    Miller, J R; McClay, D R

    1997-12-15

    During development, the modulation of cadherin adhesive function is proposed to control various morphogenetic events including epithelial-mesenchymal conversions and tubulogenesis, although the mechanisms responsible for regulating cadherin activity during these events remain unclear. In order to gain insights into the regulation of cadherin function during morphogenesis, we utilized the sea urchin embryo as a model system to study the regulation of cadherin localization during epithelial-mesenchymal conversion and convergent-extension movements. Polyclonal antibodies raised against the cytoplasmic domain of a cloned sea urchin cadherin recognize three major polypeptides of M(r) 320, 140, and 125 kDa and specifically stain adherens junctions, and to a lesser extent, lateral membrane domains in all epithelial tissues of the embryo. Analysis of embryos during gastrulation demonstrates that changes in cadherin localization are observed in cells undergoing an epithelial-mesenchymal conversion. Ingression of primary mesenchyme cells is accompanied by the rapid loss of junctional cadherin staining and the coincident accumulation of cadherin in intracellular organelles. These data are consistent with the idea that the deadhesion of mesenchymal cells from neighboring epithelial cells involves the regulated endocytosis of cell surface cadherin molecules. Conversely, neither cadherin abundance nor localization is altered in cells of the gut which undergo convergent-extension movements during the formation of the archenteron. This observation indicates that these movements do not require the loss of junctional cadherin molecules. Instead, the necessary balance between adhesion and motility may be achieved by regulating the expression of different subtypes of cadherin molecules or modifying interactions between cadherins and catenins, proteins that bind the cytoplasmic domain of cadherin and are necessary for cadherin adhesive function. To address cadherin function at the

  5. The genomic underpinnings of apoptosis in the silkworm, Bombyx mori

    PubMed Central

    2010-01-01

    Background Apoptosis is regulated in an orderly fashion by a series of genes, and has a crucial role in important physiological processes such as growth development, immunological response and so on. Recently, substantial studies have been undertaken on apoptosis in model animals including humans, fruit flies, and the nematode. However, the lack of genomic data for silkworms limits their usefulness in apoptosis studies, despite the advantages of silkworm as a representative of Lepidoptera and an effective model system. Herein we have identified apoptosis-related genes in the silkworm Bombyx mori and compared them to those from insects, mammals, and nematodes. Results From the newly assembled genome databases, a genome-wide analysis of apoptosis-related genes in Bombyx mori was performed using both nucleotide and protein Blast searches. Fifty-two apoptosis-related candidate genes were identified, including five caspase family members, two tumor necrosis factor (TNF) superfamily members, one Bcl-2 family member, four baculovirus IAP (inhibitor of apoptosis) repeat (BIR) domain family members and 1 RHG (Reaper, Hid, Grim, and Sickle; Drosophila cell death activators) family member. Moreover, we identified a new caspase family member, BmCaspase-New, two splice variants of BmDronc, and Bm3585, a mammalian TNF superfamily member homolog. Twenty-three of these apoptosis-related genes were cloned and sequenced using cDNA templates isolated from BmE-SWU1 cells. Sequence analyses revealed that these genes could have key roles in apoptosis. Conclusions Bombyx mori possesses potential apoptosis-related genes. We hypothesized that the classic intrinsic and extrinsic apoptotic pathways potentially are active in Bombyx mori. These results lay the foundation for further apoptosis-related study in Bombyx mori. PMID:21040523

  6. Effects of N-Cadherin Disruption on Spine Morphological Dynamics

    PubMed Central

    Mysore, Shreesh P.; Tai, Chin-Yin; Schuman, Erin M.

    2007-01-01

    Structural changes at synapses are thought to be a key mechanism for the encoding of memories in the brain. Recent studies have shown that changes in the dynamic behavior of dendritic spines accompany bidirectional changes in synaptic plasticity, and that the disruption of structural constraints at synapses may play a mechanistic role in spine plasticity. While the prolonged disruption of N-cadherin, a key synaptic adhesion molecule, has been shown to alter spine morphology, little is known about the short-term regulation of spine morphological dynamics by N-cadherin. With time-lapse, confocal imaging in cultured hippocampal neurons, we examined the progression of structural changes in spines following an acute treatment with AHAVD, a peptide known to interfere with the function of N-cadherin. We characterized fast and slow timescale spine dynamics (minutes and hours, respectively) in the same population of spines. We show that N-cadherin disruption leads to enhanced spine motility and reduced length, followed by spine loss. The structural effects are accompanied by a loss of functional connectivity. Further, we demonstrate that early structural changes induced by AHAVD treatment, namely enhanced motility and reduced length, are indicators for later spine fate, i.e., spines with the former changes are more likely to be subsequently lost. Our results thus reveal the short-term regulation of synaptic structure by N-cadherin and suggest that some forms of morphological dynamics may be potential readouts for subsequent, stimulus-induced rewiring in neuronal networks. PMID:18946519

  7. Cadherin Mechanics and Complexation: The Importance of Calcium Binding

    PubMed Central

    Cailliez, Fabien; Lavery, Richard

    2005-01-01

    E-cadherins belong to a family of membrane-bound, cellular adhesion proteins. Their adhesive properties mainly involve the two N-terminal extracellular domains (EC1 and EC2). The junctions between these domains are characterized by calcium ion binding sites, and calcium ions are essential for the correct functioning of E-cadherins. Calcium is believed to rigidify the extracellular portion of the protein, which, when complexed, adopts a rod-like conformation. Here, we use molecular dynamics simulations to investigate the dynamics of the EC1-2 portion of E-cadherin in the presence and in the absence of calcium ions. These simulations confirm that apo-cadherin shows much higher conformational flexibility on a nanosecond timescale than the calcium-bound form. It is also shown that although the apo-cadherin fragment can spontaneously complex potassium, these monovalent ions are incapable of rigidifying the interdomain junctions. In contrast, removal of the most solvent-exposed calcium ion at the EC1-2 junction does not significantly perturb the dynamical behavior of the fragment. We have also extended this study to the cis-dimer formed from two EC1-2 fragments, potentially involved in cellular adhesion. Here again, it is shown that the presence of calcium is an important factor in both rigidifying and stabilizing the complex. PMID:16183887

  8. N-Cadherin in Neuroblastoma Disease: Expression and Clinical Significance

    PubMed Central

    Derycke, Lara; De Craemer, Annemie; De Brouwer, Sara; De Preter, Katleen; Van Roy, Nadine; Vandesompele, Jo; Speleman, Frank; Philippé, Jan; Benoit, Yves; Beiske, Klaus; Bracke, Marc; Laureys, Geneviève

    2012-01-01

    One of the first and most important steps in the metastatic cascade is the loss of cell-cell and cell-matrix interactions. N-cadherin, a crucial mediator of homotypic and heterotypic cell-cell interactions, might play a central role in the metastasis of neuroblastoma (NB), a solid tumor of neuroectodermal origin. Using Reverse Transcription Quantitative PCR (RT-qPCR), Western blot, immunocytochemistry and Tissue MicroArrays (TMA) we demonstrate the expression of N-cadherin in neuroblastoma tumors and cell lines. All neuroblastic tumors (n = 356) and cell lines (n = 10) expressed various levels of the adhesion protein. The N-cadherin mRNA expression was significantly lower in tumor samples from patients suffering metastatic disease. Treatment of NB cell lines with the N-cadherin blocking peptide ADH-1 (Exherin, Adherex Technologies Inc.), strongly inhibited tumor cell proliferation in vitro by inducing apoptosis. Our results suggest that N-cadherin signaling may play a role in neuroblastoma disease, marking involvement of metastasis and determining neuroblastoma cell viability. PMID:22355346

  9. Resolving the molecular mechanism of cadherin catch bond formation

    NASA Astrophysics Data System (ADS)

    Manibog, Kristine; Li, Hui; Rakshit, Sabyasachi; Sivasankar, Sanjeevi

    2014-06-01

    Classical cadherin Ca2+-dependent cell-cell adhesion proteins play key roles in embryogenesis and in maintaining tissue integrity. Cadherins mediate robust adhesion by binding in multiple conformations. One of these adhesive states, called an X-dimer, forms catch bonds that strengthen and become longer lived in the presence of mechanical force. Here we use single-molecule force-clamp spectroscopy with an atomic force microscope along with molecular dynamics and steered molecular dynamics simulations to resolve the molecular mechanisms underlying catch bond formation and the role of Ca2+ ions in this process. Our data suggest that tensile force bends the cadherin extracellular region such that they form long-lived, force-induced hydrogen bonds that lock X-dimers into tighter contact. When Ca2+ concentration is decreased, fewer de novo hydrogen bonds are formed and catch bond formation is eliminated.

  10. ID2 predicts poor prognosis in breast cancer, especially in triple-negative breast cancer, and inhibits E-cadherin expression

    PubMed Central

    Li, Kai; Yao, Ling; Chen, Li; Cao, Zhi-Gang; Yu, San-Jian; Kuang, Xia-Ying; Hu, Xin; Shao, Zhi-Ming

    2014-01-01

    Background Inhibitors of DNA-binding (ID) proteins are known as important modulators in the regulation of cell proliferation and differentiation. This study sought to investigate the prognostic value of ID proteins in breast cancer. Methods The prognostic role of ID proteins in human breast cancer was investigated in 250 breast cancers, via tissue microarrays. The messenger (m)RNA and protein levels of E-cadherin were examined by quantitative reverse-transcription polymerase chain reaction (qRT-PCR) and Western blotting, in cells overexpressing IDs. Dual-luciferase report assay was used to investigate the potential mechanism, and a migration assay was performed to investigate the influence of IDs on cell migratory activity. Results The survival analysis with Kaplan–Meier and Cox regression showed that ID2 expression level, which correlated with estrogen receptor status and E-cadherin abundance, served as an independent prognostic factor for disease-free survival (DFS) (P=0.013). The prognostic value of ID2 for DFS was most significant in triple-negative breast cancer patients (P=0.009). We also found that ID2 was negatively correlated with E-cadherin expression by correlation analysis (P=0.020, Pearson’s R=−0.155). Subsequently, we explored the biological rationale and uncovered that the enforced expression of ID proteins could suppress E-cadherin expression significantly, thus increasing the migration ability of mammary epithelial cells. Then using a combination of ID2 and E-cadherin expression, the patients were classified into four subgroups with different DFS (P=0.023). Conclusion The overexpression of ID2 can be used as a prognostic marker in breast cancer patients, especially in triple-negative breast cancer patients. ID proteins were still, unexpectedly, revealed to inhibit E-cadherin abundance. PMID:24971018

  11. N-Cadherin Aided in Maintaining the Characteristics of Leukemic Stem Cells.

    PubMed

    Zhi, Lei; Gao, Ying; Yu, Chunyan; Zhang, Yi; Zhang, Bo; Yang, Jie; Yao, Zhi

    2016-07-01

    In our previous study, it has been revealed that N-cadherin(+) and leukemic stem cells (LSCs, CD34(+) /CD38(-) /CD123(+) ) could be enriched by chemotherapy because of their resistance to chemotherapy. In this study, we found that N-cadherin mRNA was highly expressed in the bone marrow mononuclear cells (BMMNCs) of patients with t(8;21) translocation. To determine the role of N-cadherin in maintaining LSCs self-renewal and stationary properties, colony-forming assay, cell cycle analysis, and engraftment in nonobese diabetic/severe combined immunodeficiency (NOD/SCID) mice were used to compare N-cadherin(+) and N-cadherin(-) cells. Both leukemic cell lines KG1a and CD34(+) /CD38(-) BMMNCs derived from acute myeloid leukemia patients were used, and cells were divided into N-cadherin(+) and N-cadherin(-) fraction after sorting by FACS. The results showed that N-cadherin(+) cells had remarkable increased numbers of colonies with cytokines stimulation when compared with the negative control, suggesting a higher proliferative capacity of N-cadherin(+) cells with cytokines stimulation. The results also showed that most cells in N-cadherin(+) fraction stayed in the G0 -G1 stage, indicating the involvement of N-cadherin in maintaining the quiescent state of LSCs in niche. The results of engraftment showed that there was a higher proportion of hCD45(+) cells in mice transplanted with N-cadherin(+) cells than N-cadherin(-) cells. In addition, it was obvious that NOD/SCID mice transplanted with N-cadherin(+) cells had a shorter lifetime than the negative control, suggesting that LSCs self-renewal capacity resides predominantly in N-cadherin(+) fraction. In summary, N-cadherin might play an important role in maintaining the self-renewal and stationary properties of LSCs. Anat Rec, 299:990-998, 2016. © 2016 Wiley Periodicals, Inc. PMID:27064800

  12. Effect of Venom from the Jellyfish Nemopilema nomurai on the Silkworm Bombyx mori L

    PubMed Central

    Yu, Huahua; Li, Rongfeng; Chen, Xiaolin; Yue, Yang; Xing, Ronge; Liu, Song; Li, Pengcheng

    2015-01-01

    The silkworm Bombyx mori L. (B. mori) has a significant impact on the economy by producing more than 80% of the globally produced raw silk. The exposure of silkworm to pesticides may cause adverse effects on B. mori, such as a reduction in the production and quality of silk. This study aims to assay the effect of venom from the jellyfish Nemopilema nomurai on growth, cuticle and acetylcholinesterase (AChE) activity of the silkworm B. mori by the leaf dipping method. The experimental results revealed that the four samples caused neither antifeeding nor a lethal effect on B. mori. The sample SFV inhibited B. mori growth after 6 days of treatment in a dose-dependent manner. The samples SFV, DSFV and Fr-1 inhibited the precipitation and synthesis of chitin in the cuticle after 12 and 14 days of treatment. In the case of the four samples, the AChE was significantly improved after 14 days of treatment. PMID:26404374

  13. Effect of Venom from the Jellyfish Nemopilema nomurai on the Silkworm Bombyx mori L.

    PubMed

    Yu, Huahua; Li, Rongfeng; Chen, Xiaolin; Yue, Yang; Xing, Ronge; Liu, Song; Li, Pengcheng

    2015-10-01

    The silkworm Bombyx mori L. (B. mori) has a significant impact on the economy by producing more than 80% of the globally produced raw silk. The exposure of silkworm to pesticides may cause adverse effects on B. mori, such as a reduction in the production and quality of silk. This study aims to assay the effect of venom from the jellyfish Nemopilema nomurai on growth, cuticle and acetylcholinesterase (AChE) activity of the silkworm B. mori by the leaf dipping method. The experimental results revealed that the four samples caused neither antifeeding nor a lethal effect on B. mori. The sample SFV inhibited B. mori growth after 6 days of treatment in a dose-dependent manner. The samples SFV, DSFV and Fr-1 inhibited the precipitation and synthesis of chitin in the cuticle after 12 and 14 days of treatment. In the case of the four samples, the AChE was significantly improved after 14 days of treatment. PMID:26404374

  14. A novel role for p120 catenin in E-cadherin function

    PubMed Central

    Ireton, Reneé C.; Davis, Michael A.; van Hengel, Jolanda; Mariner, Deborah J.; Barnes, Kirk; Thoreson, Molly A.; Anastasiadis, Panos Z.; Matrisian, Linsey; Bundy, Linda M.; Sealy, Linda; Gilbert, Barbara; van Roy, Frans; Reynolds, Albert B.

    2002-01-01

    Îndirect evidence suggests that p120-catenin (p120) can both positively and negatively affect cadherin adhesiveness. Here we show that the p120 gene is mutated in SW48 cells, and that the cadherin adhesion system is impaired as a direct consequence of p120 insufficiency. Restoring normal levels of p120 caused a striking reversion from poorly differentiated to cobblestone-like epithelial morphology, indicating a crucial role for p120 in reactivation of E-cadherin function. The rescue efficiency was enhanced by increased levels of p120, and reduced by the presence of the phosphorylation domain, a region previously postulated to confer negative regulation. Surprisingly, the rescue was associated with substantially increased levels of E-cadherin. E-cadherin mRNA levels were unaffected by p120 expression, but E-cadherin half-life was more than doubled. Direct p120–E-cadherin interaction was crucial, as p120 deletion analysis revealed a perfect correlation between E-cadherin binding and rescue of epithelial morphology. Interestingly, the epithelial morphology could also be rescued by forced expression of either WT E-cadherin or a p120-uncoupled mutant. Thus, the effects of uncoupling p120 from E-cadherin can be at least partially overcome by artificially maintaining high levels of cadherin expression. These data reveal a cooperative interaction between p120 and E-cadherin and a novel role for p120 that is likely indispensable in normal cells. PMID:12427869

  15. Enhanced Biological Functions of Human Mesenchymal Stem-Cell Aggregates Incorporating E-Cadherin-Modified PLGA Microparticles.

    PubMed

    Zhang, Yan; Mao, Hongli; Gao, Chao; Li, Suhua; Shuai, Qizhi; Xu, Jianbin; Xu, Ke; Cao, Lei; Lang, Ren; Gu, Zhongwei; Akaike, Toshihiro; Yang, Jun

    2016-08-01

    Mesenchymal stem cells (MSCs) have emerged as a promising source of multipotent cells for various cell-based therapies due to their unique properties, and formation of 3D MSC aggregates has been explored as a potential strategy to enhance therapeutic efficacy. In this study, poly(lactic-co-glycolic acid) (PLGA) microparticles modified with human E-cadherin fusion protein (hE-cad-PLGA microparticles) have been fabricated and integrated with human MSCs to form 3D cell aggregates. The results show that, compared with the plain PLGA, the hE-cad-PLGA microparticles distribute within the aggregates more evenly and further result in a more significant improvement of cellular proliferation and secretion of a series of bioactive factors due to the synergistic effects from the bioactive E-cadherin fragments and the PLGA microparticles. Meanwhile, the hE-cad-PLGA microparticles incorporated in the aggregates upregulate the phosphorylation of epidermal growth factor receptors and activate the AKT and ERK1/2 signaling pathways in the MSCs. Additionally, the E-cadherin/β-catenin cellular membrane complex in the MSCs is markedly stimulated by the hE-cad-PLGA microparticles. Therefore, engineering 3D cell aggregates with hE-cad-PLGA microparticles can be a promising method for ex vivo multipotent stem-cell expansion with enhanced biological functions and may offer a novel route to expand multipotent stem-cell-based clinical applications. PMID:27245478

  16. Phosphatase activity of Bombyx mori nucleopolyhedrovirus PTP is dispensable for enhanced locomotory activity in B. mori larvae.

    PubMed

    Katsuma, Susumu

    2015-11-01

    Baculovirus-induced enhanced locomotory activity (ELA) is not induced in caterpillars infected with a mutant Bombyx mori nucleopolyhedrovirus (BmNPV) or Autographa californica multiple nucleopolyhedrovirus (AcMNPV) lacking a functional protein tyrosine phosphatase gene (ptp). Previous studies suggest that the PTP proteins from BmNPV and AcMNPV act in different ways to induce ELA, i.e., BmNPV PTP is utilized as a virion structural component, whereas AcMNPV PTP requires its phosphatase activity. Here, I generated and characterized two new BmNPV mutants expressing enzymatically inactive PTP proteins and confirmed that the phosphatase activity of PTP is not required for ELA induction in BmNPV-infected B. mori larvae. PMID:26550695

  17. Two-step adhesive binding by classical cadherins

    PubMed Central

    Harrison, Oliver; Bahna, Fabiana; Katsamba, Phini; Jin, Xiangshu; Brasch, Julia; Vendome, Jeremie; Ahlsen, Goran; Carroll, Kilpatrick; Price, Stephen; Honig, Barry; Shapiro, Lawrence

    2010-01-01

    Crystal structures of classical cadherins have revealed two dimeric configurations: in the first, N-terminal β-strands of EC1 domains “swap” between partner molecules. The second configuration (the “X-dimer”), also observed for T-cadherin, is mediated by residues near the EC1-2 calcium binding sites, and N-terminal β-strands of partner EC1 domains, though held adjacent, do not swap. Here we show that strand swapping mutants of type I and II classical cadherins form X-dimers. Mutant cadherins impaired for X-dimer formation show no binding in short timeframe surface plasmon resonance assays but in long timeframe experiments, have homophilic binding affinities close to wild-type. Further experiments show that exchange between monomers and dimers is slowed in these mutants. These results reconcile apparently disparate results from prior structural studies, and suggest that X-dimers are binding intermediates that facilitate the formation of strand swapped dimers. PMID:20190754

  18. Expression patterns of cadherin genes in Drosophila oogenesis

    PubMed Central

    Zartman, Jeremiah J.; Kanodia, Jitendra S.; Yakoby, Nir; Schafer, Xenia; Watson, Colin; Schlichting, Karin; Dahmann, Christian; Shvartsman, Stanislav Y.

    2014-01-01

    In Drosophila oogenesis, the follicular epithelium that envelops the oocyte is patterned by a small set of inductive signals and gives rise to an elaborate three-dimensional eggshell. Several eggshell structures provide sensitive readouts of the patterning signals, but the formation of these structures is still poorly understood. In other systems, epithelial morphogenesis is guided by the spatial patterning of cell adhesion and cytoskeleton genes. As a step towards developing a comprehensive description of patterning events leading to eggshell morphogenesis, we report the expression of Drosophila cadherins, calcium dependent adhesion molecules that are repeatedly used throughout development. We found that 9/17 of Drosophila cadherins are expressed in the follicular epithelium in dynamic patterns during oogenesis. In late oogenesis, the expression patterns of cadherin genes in the main body follicle cells is summarized using a compact set of simple geometric shapes, reflecting the integration of the EGFR and DPP inductive signals. The multi-layered composite patterning of the cadherins is hypothesized to play a key role in the formation of the eggshell. Of particular note is the complex patterning of the region of the follicular epithelium that gives rise to the dorsal appendages, which are tubular structures that serve as respiratory organs for the developing embryo. PMID:18817893

  19. Two-step Adhesive Binding by Classical Cadherins

    SciTech Connect

    Harrison, O.; Bahna, F; Katsamba, P; Jin, X; Brasch, J; Carroll, K; Price, S; Honig, B; Shapiro, L; et al.

    2010-01-01

    Crystal structures of classical cadherins have revealed two dimeric configurations. In the first, N-terminal {beta}-strands of EC1 domains 'swap' between partner molecules. The second configuration (the 'X dimer'), also observed for T-cadherin, is mediated by residues near the EC1-EC2 calcium binding sites, and N-terminal {beta}-strands of partner EC1 domains, though held adjacent, do not swap. Here we show that strand-swapping mutants of type I and II classical cadherins form X dimers. Mutant cadherins impaired for X-dimer formation show no binding in short-time frame surface plasmon resonance assays, but in long-time frame experiments, they have homophilic binding affinities close to that of wild type. Further experiments show that exchange between monomers and dimers is slowed in these mutants. These results reconcile apparently disparate results from prior structural studies and suggest that X dimers are binding intermediates that facilitate the formation of strand-swapped dimers.

  20. Tuning Molecular Weights of Bombyx mori (B. mori) Silk Sericin to Modify Its Assembly Structures and Materials Formation

    PubMed Central

    2015-01-01

    Bombyx mori (B. mori) silk sericin is a protein with features desirable as a biomaterial, such as increased hydrophilicity and biodegradation, as well as resistance to oxidation, bacteria, and ultraviolet light. In contrast to other widely studied B. mori silk proteins such as fibroin, sericin is still unexplored as a building block for fabricating biomaterial, and thus a facile technique of processing it into a material is needed. Here, electrospinning technology was used to fabricate it into biomaterials from two forms of B. mori silk sericin with different molecular weights, one is a low (12.0 kDa) molecular sericin (LS) form and another is a high (66.0 kDa) molecular weight sericin (HS) form. Circular dichroism (CD) spectra showed that LS in hexafluoroacetone (HFA) solvent adopted a predominantly random coil conformation, whereas HS tended to form a β-sheet structure along with a large content of random coils. In addition, LS and HS in HFA solvent were found to form cylinder-like smaller nanoparticles and larger irregular aggregates before electrospinning, respectively. As a result, biomaterials based on microparticles and nanofibers were successfully fabricated by electrospinning of LS and HS dissolved in HFA, respectively. The cell viability and differentiation assay indicated that nanofibers and microparticles improved cell adhesion, growth, and differentiation, proving that the scaffolds electrospun from sericin are biocompatible regardless of its molecular weight. The microparticles, not common in electrospinning of silk proteins reported previously, were found to promote the osteogenic differentiation of mesenchymal stem cells in comparison to the nanofibers. This study suggested that molecular weight of sericin mediates its secondary structure and assembly structure, which in turn leads to a control of final morphology of the electrospun materials. The microparticles and nanofibers of sericin can be potentially used as building blocks for fabricating

  1. Sialylation potentials of the silkworm, Bombyx mori; B. mori possesses an active α2,6-sialyltransferase.

    PubMed

    Kajiura, Hiroyuki; Hamaguchi, Yuichi; Mizushima, Hiroki; Misaki, Ryo; Fujiyama, Kazuhito

    2015-12-01

    N-Glycosylation is an important post-translational modification in most secreted and membrane-bound proteins in eukaryotic cells. However, the insect N-glycosylation pathway and the potentials contributing to the N-glycan synthesis are still unclear because most of the studies on these subjects have focused on mammals and plants. Here, we identified Bombyx mori sialyltransferase (BmST), which is a Golgi-localized glycosyltransferase and which can modify N-glycans. BmST was ubiquitously expressed in different organs and in various stages of development and localized at the Golgi. Biochemical analysis using Sf9-expressed BmST revealed that BmST encoded α2,6-sialyltransferase and transferred N-acetylneuraminic acid (NeuAc) to the nonreducing terminus of Galβ1-R, but exhibited the highest activity toward GalNAcβ1,4-GlcNAc-R. Unlike human α2,6-sialyltransferase, BmST required the post-translational modification, especially N-glycosylation, for its full activity. N-Glycoprotein analysis of B. mori fifth instar larvae revealed that high-mannose-type structure was predominant and GlcNAc-linked and fucosylated structures were observed but endogenous galactosyl-, N-acetylgalactosaminyl- and sialyl-N-glycoproteins were undetectable under the standard analytical approach. These results indicate that B. mori genome encodes an α2,6-sialyltransferase, but further investigations of the sialylation potentials are necessary. PMID:26306633

  2. E-cadherin interactome complexity and robustness resolved by quantitative proteomics.

    PubMed

    Guo, Zhenhuan; Neilson, Lisa J; Zhong, Hang; Murray, Paul S; Zanivan, Sara; Zaidel-Bar, Ronen

    2014-12-01

    E-cadherin-mediated cell-cell adhesion and signaling plays an essential role in development and maintenance of healthy epithelial tissues. Adhesiveness mediated by E-cadherin is conferred by its extracellular cadherin domains and is regulated by an assembly of intracellular adaptors and enzymes associated with its cytoplasmic tail. We used proximity biotinylation and quantitative proteomics to identify 561 proteins in the vicinity of the cytoplasmic tail of E-cadherin. In addition, we used proteomics to identify proteins associated with E-cadherin-containing adhesion plaques from a cell-glass interface, which enabled the assignment of cellular localization to putative E-cadherin-interacting proteins. Moreover, by tagging identified proteins with GFP (green fluorescent protein), we determined the subcellular localization of 83 putative E-cadherin-proximal proteins and identified 24 proteins that were previously uncharacterized as part of adherens junctions. We constructed and characterized a comprehensive E-cadherin interaction network of 79 published and 394 previously uncharacterized proteins using a structure-informed database of protein-protein interactions. Finally, we found that calcium chelation, which disrupts the interaction of the extracellular E-cadherin domains, did not disrupt most intracellular protein interactions with E-cadherin, suggesting that the E-cadherin intracellular interactome is predominantly independent of cell-cell adhesion. PMID:25468996

  3. Characterization of Ascites-Derived Ovarian Tumor Cells from Spontaneously Occurring Ovarian Tumors of the Chicken: Evidence for E-Cadherin Upregulation

    PubMed Central

    Tiwari, Anupama; Hadley, Jill A.; Hendricks, Gilbert L.; Elkin, Robert G.; Cooper, Timothy; Ramachandran, Ramesh

    2013-01-01

    Ovarian cancer, a highly metastatic disease, is the fifth leading cause of cancer-related deaths in women. Chickens are widely used as a model for human ovarian cancer as they spontaneously develop epithelial ovarian tumors similar to humans. The cellular and molecular biology of chicken ovarian cancer (COVCAR) cells, however, have not been studied. Our objectives were to culture COVCAR cells and to characterize their invasiveness and expression of genes and proteins associated with ovarian cancer. COVCAR cell lines (n = 13) were successfully maintained in culture for up to19 passages, cryopreserved and found to be viable upon thawing and replating. E-cadherin, cytokeratin and α-smooth muscle actin were localized in COVCAR cells by immunostaining. COVCAR cells were found to be invasive in extracellular matrix and exhibited anchorage-independent growth forming colonies, acini and tube-like structures in soft agar. Using RT-PCR, COVCAR cells were found to express E-cadherin, N-cadherin, cytokeratin, vimentin, mesothelin, EpCAM, steroidogenic enzymes/proteins, inhibin subunits-α, βA, βB, anti-müllerian hormone, estrogen receptor [ER]-α, ER-β, progesterone receptor, androgen receptor, and activin receptors. Quantitative PCR analysis revealed greater N-cadherin, vimentin, and VEGF mRNA levels and lesser cytokeratin mRNA levels in COVCAR cells as compared with normal ovarian surface epithelial (NOSE) cells, which was suggestive of epithelial-mesenchymal transformation. Western blotting analyses revealed significantly greater E-cadherin levels in COVCAR cell lines compared with NOSE cells. Furthermore, cancerous ovaries and COVCAR cell lines expressed higher levels of an E-cadherin cleavage product when compared to normal ovaries and NOSE cells, respectively. Cancerous ovaries were found to express significantly higher ovalbumin levels whereas COVCAR cell lines did not express ovalbumin thus suggesting that the latter did not originate from oviduct. Taken

  4. Characterization of ascites-derived ovarian tumor cells from spontaneously occurring ovarian tumors of the chicken: evidence for E-cadherin upregulation.

    PubMed

    Tiwari, Anupama; Hadley, Jill A; Hendricks, Gilbert L; Elkin, Robert G; Cooper, Timothy; Ramachandran, Ramesh

    2013-01-01

    Ovarian cancer, a highly metastatic disease, is the fifth leading cause of cancer-related deaths in women. Chickens are widely used as a model for human ovarian cancer as they spontaneously develop epithelial ovarian tumors similar to humans. The cellular and molecular biology of chicken ovarian cancer (COVCAR) cells, however, have not been studied. Our objectives were to culture COVCAR cells and to characterize their invasiveness and expression of genes and proteins associated with ovarian cancer. COVCAR cell lines (n = 13) were successfully maintained in culture for up to19 passages, cryopreserved and found to be viable upon thawing and replating. E-cadherin, cytokeratin and α-smooth muscle actin were localized in COVCAR cells by immunostaining. COVCAR cells were found to be invasive in extracellular matrix and exhibited anchorage-independent growth forming colonies, acini and tube-like structures in soft agar. Using RT-PCR, COVCAR cells were found to express E-cadherin, N-cadherin, cytokeratin, vimentin, mesothelin, EpCAM, steroidogenic enzymes/proteins, inhibin subunits-α, βA, βB, anti-müllerian hormone, estrogen receptor [ER]-α, ER-β, progesterone receptor, androgen receptor, and activin receptors. Quantitative PCR analysis revealed greater N-cadherin, vimentin, and VEGF mRNA levels and lesser cytokeratin mRNA levels in COVCAR cells as compared with normal ovarian surface epithelial (NOSE) cells, which was suggestive of epithelial-mesenchymal transformation. Western blotting analyses revealed significantly greater E-cadherin levels in COVCAR cell lines compared with NOSE cells. Furthermore, cancerous ovaries and COVCAR cell lines expressed higher levels of an E-cadherin cleavage product when compared to normal ovaries and NOSE cells, respectively. Cancerous ovaries were found to express significantly higher ovalbumin levels whereas COVCAR cell lines did not express ovalbumin thus suggesting that the latter did not originate from oviduct. Taken

  5. PTEN Loss in E-Cadherin-Deficient Mouse Mammary Epithelial Cells Rescues Apoptosis and Results in Development of Classical Invasive Lobular Carcinoma.

    PubMed

    Boelens, Mirjam C; Nethe, Micha; Klarenbeek, Sjoerd; de Ruiter, Julian R; Schut, Eva; Bonzanni, Nicola; Zeeman, Amber L; Wientjens, Ellen; van der Burg, Eline; Wessels, Lodewyk; van Amerongen, Renée; Jonkers, Jos

    2016-08-23

    Invasive lobular carcinoma (ILC) is an aggressive breast cancer subtype with poor response to chemotherapy. Besides loss of E-cadherin, a hallmark of ILC, genetic inactivation of PTEN is frequently observed in patients. Through concomitant Cre-mediated inactivation of E-cadherin and PTEN in mammary epithelium, we generated a mouse model of classical ILC (CLC), the main histological ILC subtype. While loss of E-cadherin induced cell dissemination and apoptosis, additional PTEN inactivation promoted cell survival and rapid formation of invasive mammary tumors that recapitulate the histological and molecular features, estrogen receptor (ER) status, growth kinetics, metastatic behavior, and tumor microenvironment of human CLC. Combined inactivation of E-cadherin and PTEN is sufficient to cause CLC development. These CLCs showed significant tumor regression upon BEZ235-mediated inhibition of PI3K signaling. In summary, this mouse model provides important insights into CLC development and suggests inhibition of phosphatidylinositol 3-kinase (PI3K) signaling as a potential therapeutic strategy for targeting CLC. PMID:27524621

  6. Molecular and neural mechanisms of sex pheromone reception and processing in the silkmoth Bombyx mori

    PubMed Central

    Sakurai, Takeshi; Namiki, Shigehiro; Kanzaki, Ryohei

    2014-01-01

    Male moths locate their mates using species-specific sex pheromones emitted by conspecific females. One striking feature of sex pheromone recognition in males is the high degree of specificity and sensitivity at all levels, from the primary sensory processes to behavior. The silkmoth Bombyx mori is an excellent model insect in which to decipher the underlying mechanisms of sex pheromone recognition due to its simple sex pheromone communication system, where a single pheromone component, bombykol, elicits the full sexual behavior of male moths. Various technical advancements that cover all levels of analysis from molecular to behavioral also allow the systematic analysis of pheromone recognition mechanisms. Sex pheromone signals are detected by pheromone receptors expressed in olfactory receptor neurons in the pheromone-sensitive sensilla trichodea on male antennae. The signals are transmitted to the first olfactory processing center, the antennal lobe (AL), and then are processed further in the higher centers (mushroom body and lateral protocerebrum) to elicit orientation behavior toward females. In recent years, significant progress has been made elucidating the molecular mechanisms underlying the detection of sex pheromones. In addition, extensive studies of the AL and higher centers have provided insights into the neural basis of pheromone processing in the silkmoth brain. This review describes these latest advances, and discusses what these advances have revealed about the mechanisms underlying the specific and sensitive recognition of sex pheromones in the silkmoth. PMID:24744736

  7. Cadherin is involved in the action of Bacillus thuringiensis toxins Cry1Ac and Cry2Aa in the beet armyworm, Spodoptera exigua.

    PubMed

    Qiu, Lin; Hou, Leilei; Zhang, Boyao; Liu, Lang; Li, Bo; Deng, Pan; Ma, Weihua; Wang, Xiaoping; Fabrick, Jeffrey A; Chen, Lizhen; Lei, Chaoliang

    2015-05-01

    Bacillus thuringiensis (Bt) insecticidal crystal (Cry) proteins are effective against some insect pests in sprays and transgenic crops, although the evolution of resistance could threaten the long-term efficacy of such Bt use. One strategy to delay resistance to Bt crops is to "pyramid" two or more Bt proteins that bind to distinct receptor proteins within the insect midgut. The most common Bt pyramid in cotton (Gossypium hirsutum L.) employs Cry1Ac with Cry2Ab to target several key lepidopteran pests, including the beet armyworm, Spodoptera exigua (Hübner), which is a serious migratory pest of many vegetable crops and is increasingly important in cotton in China. While cadherin and aminopeptidase-N are key receptors of Cry1 toxins in many lepidopterans including S. exigua, the receptor for Cry2A toxins remains poorly characterized. Here, we show that a heterologous expressed peptide corresponding to cadherin repeat 7 to the membrane proximal extracellular domain (CR7-MPED) in the S. exigua cadherin 1b (SeCad1b) binds Cry1Ac and Cry2Aa. Moreover, SeCad1b transcription was suppressed in S. exigua larvae by oral RNA interference and susceptibility to Cry1Ac and Cry2Aa was significantly reduced. These results indicate that SeCad1b plays important functional roles of both Cry1Ac and Cry2Aa, having major implications for resistance management for S. exigua in Bt crops. PMID:25754522

  8. Surface display and bioactivity of Bombyx mori acetylcholinesterase on Pichia pastoris

    Technology Transfer Automated Retrieval System (TEKTRAN)

    To construct the Pichia pastoris (P. pastoris) cell surface display system of Bombyx mori acetylcholinesterase (BmAChE), the gene for the anchor protein (AGa1) was obtained from Saccharomyces cerevisiae and was fused with the modified Bombyx mori acetylcholinesterase gene (bmace) and transformed int...

  9. BmRobo1a and BmRobo1b control axon repulsion in the silkworm Bombyx mori.

    PubMed

    Li, Xiao-Tong; Yu, Qi; Zhou, Qi-Sheng; Zhao, Xiao; Liu, Zhao-Yang; Cui, Wei-Zheng; Liu, Qing-Xin

    2016-02-15

    The development of the nervous system is based on the growth and connection of axons, and axon guidance molecules are the dominant regulators during this course. Robo, as the receptor of axon guidance molecule Slit, plays a key role as a conserved repellent cue for axon guidance during the development of the central nervous system. However, the function of Robo in the silkworm Bombyx mori is unknown. In this study, we cloned two novel robo genes in B. mori (Bmrobo1a and Bmrobo1b). BmRobo1a and BmRobo1b lack an Ig and a FNIII domain in the extracellular region and the CC0 and CC2 motifs in the intracellular region. BmRobo1a and BmRobo1b were colocalized with BmSlit in the neuropil. Knock-down of Bmrobo1a and Bmrobo1b by RNA interference (RNAi) resulted in abnormal development of axons. Our results suggest that BmRobo1a and BmRobo1b have repulsive function in axon guidance, even though their structures are different from Robo1 of other species. PMID:26642898

  10. Survey and Analysis of Microsatellites in the Silkworm, Bombyx mori

    PubMed Central

    Prasad, M. Dharma; Muthulakshmi, M.; Madhu, M.; Archak, Sunil; Mita, K.; Nagaraju, J.

    2005-01-01

    We studied microsatellite frequency and distribution in 21.76-Mb random genomic sequences, 0.67-Mb BAC sequences from the Z chromosome, and 6.3-Mb EST sequences of Bombyx mori. We mined microsatellites of ≥15 bases of mononucleotide repeats and ≥5 repeat units of other classes of repeats. We estimated that microsatellites account for 0.31% of the genome of B. mori. Microsatellite tracts of A, AT, and ATT were the most abundant whereas their number drastically decreased as the length of the repeat motif increased. In general, tri- and hexanucleotide repeats were overrepresented in the transcribed sequences except TAA, GTA, and TGA, which were in excess in genomic sequences. The Z chromosome sequences contained shorter repeat types than the rest of the chromosomes in addition to a higher abundance of AT-rich repeats. Our results showed that base composition of the flanking sequence has an influence on the origin and evolution of microsatellites. Transitions/transversions were high in microsatellites of ESTs, whereas the genomic sequence had an equal number of substitutions and indels. The average heterozygosity value for 23 polymorphic microsatellite loci surveyed in 13 diverse silkmoth strains having 2–14 alleles was 0.54. Only 36 (18.2%) of 198 microsatellite loci were polymorphic between the two divergent silkworm populations and 10 (5%) loci revealed null alleles. The microsatellite map generated using these polymorphic markers resulted in 8 linkage groups. B. mori microsatellite loci were the most conserved in its immediate ancestor, B. mandarina, followed by the wild saturniid silkmoth, Antheraea assama. PMID:15371363

  11. Biochemical characterization of rab proteins from Bombyx mori.

    PubMed

    Uno, Tomohide; Moriwaki, Tsubasa; Nakamura, Masahiko; Matsubara, Mamoru; Yamagata, Hiroshi; Kanamaru, Kengo; Takagi, Michihiro

    2009-02-01

    The small GTPases known as Rab proteins are key regulators of membrane trafficking. We used RT-PCR to isolate cDNA clones of insect-specific Rab proteins (BRabN1 and BRabN2) showing low homology with known Rab proteins from other animals, from mRNA of Bombyx mori. These 2 Rabs were produced in Escherichia coli and purified. BRabN1 bound [(3)H]-GDP and [(35)S]-GTPgammaS with dissociation constants of 0.087 x 10(-6) M and 1.02 x 10(-6) M, respectively, whereas those of BRabN2 were 0.546 x 10(-6) M and 1.02 x 10(-6) M, respectively. Binding of [(35)S]-GTPgammaS to BRabN1 and N2 was inhibited by GDP and GTP. The GTP-hydrolysis activities of BRabN1 and N2 were 154 and 35.5 mmol/min/mole, respectively, and bound [(35)S]-GTPgammaS was exchanged efficiently with GTP. BRabN1 also showed ATPase activity and exchange of [(35)S]-GTPgammaS with ATP. Monoclonal antibodies against BRabN1 and N2 did not recognize any other Rab proteins, and Western blotting using the anti-BRabN1 antibody revealed a single band in the testis of B. mori. These results suggest that BRabN1 and N2 of B. mori bind GTP, convert from the GTP-bound state to the GDP-bound state by intrinsic GTP hydrolysis activity, and return to the GTP-bound state with the exchange, and that BRabN1 is specifically expressed in testis. Arch. Insect Biochem. Physiol. 2008. (c) 2008 Wiley-Liss, Inc. PMID:18949803

  12. β-Fructofuranosidase Genes of the Silkworm, Bombyx mori

    PubMed Central

    Daimon, Takaaki; Taguchi, Tomohiro; Meng, Yan; Katsuma, Susumu; Mita, Kazuei; Shimada, Toru

    2008-01-01

    Mulberry latex contains extremely high concentrations of alkaloidal sugar mimic glycosidase inhibitors, such as 1,4-dideoxy-1,4-imino-d-arabinitol (d-AB1) and 1-deoxynojirimycin (DNJ). Although these compounds do not harm the silkworm, Bombyx mori, a mulberry specialist, they are highly toxic to insects that do not normally feed on mulberry leaves. d-AB1 and DNJ are strong inhibitors of α-glucosidases (EC 3.2.1.20); however, they do not affect the activity ofβ-fructofuranosidases (EC 3.2.1.26). Althoughα-glucosidase genes are found in a wide range of organisms, β-fructofuranosidase genes have not been identified in any animals so far. In this study, we report the identification and characterization of β-fructofuranosidase genes (BmSuc1 and BmSuc2) from B. mori. The BmSuc1 gene was highly expressed in the midgut and silk gland, whereas the expression of BmSuc2 gene was not detected. BmSuc1 encodes a functional β-fructofuranosidase, whose enzymatic activity was not inhibited by DNJ or d-AB1. We also showed that BmSUC1 protein localized within the midgut goblet cell cavities. Collectively, our data clearly demonstrated that BmSuc1 serves as a sugar-digesting enzyme in the silkworm physiology. This anomalous presence of the β-fructofuranosidase gene in the B. mori genome may partly explain why the silkworm can circumvent the mulberry's defense system. PMID:18397891

  13. Role of receptors in Bacillus thuringiensis crystal toxin activity.

    PubMed

    Pigott, Craig R; Ellar, David J

    2007-06-01

    Bacillus thuringiensis produces crystalline protein inclusions with insecticidal or nematocidal properties. These crystal (Cry) proteins determine a particular strain's toxicity profile. Transgenic crops expressing one or more recombinant Cry toxins have become agriculturally important. Individual Cry toxins are usually toxic to only a few species within an order, and receptors on midgut epithelial cells have been shown to be critical determinants of Cry specificity. The best characterized of these receptors have been identified for lepidopterans, and two major receptor classes have emerged: the aminopeptidase N (APN) receptors and the cadherin-like receptors. Currently, 38 different APNs have been reported for 12 different lepidopterans. Each APN belongs to one of five groups that have unique structural features and Cry-binding properties. While 17 different APNs have been reported to bind to Cry toxins, only 2 have been shown to mediate toxin susceptibly in vivo. In contrast, several cadherin-like proteins bind to Cry toxins and confer toxin susceptibility in vitro, and disruption of the cadherin gene has been associated with toxin resistance. Nonetheless, only a small subset of the lepidopteran-specific Cry toxins has been shown to interact with cadherin-like proteins. This review analyzes the interactions between Cry toxins and their receptors, focusing on the identification and validation of receptors, the molecular basis for receptor recognition, the role of the receptor in resistant insects, and proposed models to explain the sequence of events at the cell surface by which receptor binding leads to cell death. PMID:17554045

  14. Inhibition of Epithelial to Mesenchymal Transition by E-cadherin Up-regulation via Repression of Slug Transcription and Inhibition of E-cadherin Degradation

    PubMed Central

    Adhikary, Arghya; Chakraborty, Samik; Mazumdar, Minakshi; Ghosh, Swatilekha; Mukherjee, Shravanti; Manna, Argha; Mohanty, Suchismita; Nakka, Kiran Kumar; Joshi, Shruti; De, Abhijit; Chattopadhyay, Samit; Sa, Gaurisankar; Das, Tanya

    2014-01-01

    The evolution of the cancer cell into a metastatic entity is the major cause of death in patients with cancer. It has been acknowledged that aberrant activation of a latent embryonic program, known as the epithelial-mesenchymal transition (EMT), can endow cancer cells with the migratory and invasive capabilities associated with metastatic competence for which E-cadherin switch is a well-established hallmark. Discerning the molecular mechanisms that regulate E-cadherin expression is therefore critical for understanding tumor invasiveness and metastasis. Here we report that SMAR1 overexpression inhibits EMT and decelerates the migratory potential of breast cancer cells by up-regulating E-cadherin in a bidirectional manner. While SMAR1-dependent transcriptional repression of Slug by direct recruitment of SMAR1/HDAC1 complex to the matrix attachment region site present in the Slug promoter restores E-cadherin expression, SMAR1 also hinders E-cadherin-MDM2 interaction thereby reducing ubiquitination and degradation of E-cadherin protein. Consistently, siRNA knockdown of SMAR1 expression in these breast cancer cells results in a coordinative action of Slug-mediated repression of E-cadherin transcription, as well as degradation of E-cadherin protein through MDM2, up-regulating breast cancer cell migration. These results indicate a crucial role for SMAR1 in restraining breast cancer cell migration and suggest the candidature of this scaffold matrix-associated region-binding protein as a tumor suppressor. PMID:25086032

  15. Role of N-cadherin in proliferation, migration, and invasion of germ cell tumours

    PubMed Central

    Jarry, Hubertus; Küffer, Stefan; Kaulfuss, Silke; Burfeind, Peter; Strauβ, Arne; Thelen, Paul; Radzun, Heinz Joachim; Ströbel, Philipp; Honecker, Friedemann; Behnes, Carl Ludwig

    2015-01-01

    Germ cell tumors (GCTs) are the most common malignancies in young men. Most patients with GCT can be cured with cisplatin-based combination chemotherapy, even in metastatic disease. In case of therapy resistance, prognosis is usually poor. We investigated the potential of N-cadherin inhibition as a therapeutic strategy. We analyzed the GCT cell lines NCCIT, NTERA-2, TCam-2, and the cisplatin-resistant sublines NCCIT-R and NTERA-2R. Effects of a blocking antibody or siRNA against N-cadherin on proliferation, migration, and invasion were investigated. Mouse xenografts of GCT cell lines were analyzed by immunohistochemistry for N-cadherin expression. All investigated GCT cell lines were found to express N-cadherin protein in vitro and in vivo. Downregulation of N-cadherin in vitro leads to a significant inhibition of proliferation, migration, and invasion. N-cadherin-downregulation leads to a significantly higher level of pERK. N-cadherin-inhibition resulted in significantly higher rates of apoptotic cells in caspase-3 staining. Expression of N-cadherin is preserved in cisplatin-resistant GCT cells, pointing to an important physiological role in cell survival. N-cadherin-downregulation results in a significant decrease of proliferation, migration, and invasion and stimulates apoptosis in cisplatin-naive and resistant GCT cell lines. Therefore, targeting N-cadherin may be a promising therapeutic approach, particularly in cisplatin-resistant, therapy refractory and metastatic GCT. PMID:26451610

  16. The formation of ordered nanoclusters controls cadherin anchoring to actin and cell–cell contact fluidity

    PubMed Central

    Strale, Pierre-Olivier; Duchesne, Laurence; Peyret, Grégoire; Montel, Lorraine; Nguyen, Thao; Png, Evelyn; Tampé, Robert; Troyanovsky, Sergey; Hénon, Sylvie; Ladoux, Benoit

    2015-01-01

    Oligomerization of cadherins could provide the stability to ensure tissue cohesion. Cadherins mediate cell–cell adhesion by forming trans-interactions. They form cis-interactions whose role could be essential to stabilize intercellular junctions by shifting cadherin clusters from a fluid to an ordered phase. However, no evidence has been provided so far for cadherin oligomerization in cellulo and for its impact on cell–cell contact stability. Visualizing single cadherins within cell membrane at a nanometric resolution, we show that E-cadherins arrange in ordered clusters, providing the first demonstration of the existence of oligomeric cadherins at cell–cell contacts. Studying the consequences of the disruption of the cis-interface, we show that it is not essential for adherens junction formation. Its disruption, however, increased the mobility of junctional E-cadherin. This destabilization strongly affected E-cadherin anchoring to actin and cell–cell rearrangement during collective cell migration, indicating that the formation of oligomeric clusters controls the anchoring of cadherin to actin and cell–cell contact fluidity. PMID:26195669

  17. Insulin-like growth factor I activates the invasion suppressor function of E-cadherin in MCF-7 human mammary carcinoma cells in vitro.

    PubMed Central

    Bracke, M. E.; Vyncke, B. M.; Bruyneel, E. A.; Vermeulen, S. J.; De Bruyne, G. K.; Van Larebeke, N. A.; Vleminckx, K.; Van Roy, F. M.; Mareel, M. M.

    1993-01-01

    The calcium-dependent cell-cell adhesion molecule E-cadherin has been shown to counteract invasion of epithelial neoplastic cells. Using three monoclonal antibodies, we have demonstrated the presence of E-cadherin at the surface of human MCF-7/6 mammary carcinoma cells by indirect immunofluorescence coupled to flow cytometry and by immunocytochemistry. Nevertheless, MCF-7/6 cells failed to aggregate in a medium containing 1.25 mM CaCl2, and they were invasive after confrontation with embryonic chick heart fragments in organ culture. Treatment of MCF-7/6 cells with 0.5 microgram ml-1 insulin-like growth factor I (IGF-I) led to homotypic aggregation within 5 to 10 min and inhibited invasion in vitro during at least 8 days. The effect of IGF-I on cellular aggregation was insensitive to cycloheximide. However, monoclonal antibodies that interfered with the function of either the IGF-I receptor (alpha IR3) or E-cadherin (HECD-1, MB2) blocked the effect of IGF-I on aggregation. The effects of IGF-I on aggregation and on invasion could be mimicked by 1 microgram ml-1 insulin, but not by 0.5 microgram ml-1 IGF-II. The insulin effects were presumably not mediated by the IGF-I receptor, since they could not be blocked by an antibody against this receptor (alpha IR3). Our results indicate that IGF-I activates the invasion suppressor role of E-cadherin in MCF-7/6 cells. Images Figure 1 Figure 3 Figure 4 Figure 7 Figure 8 Figure 10 PMID:8347483

  18. Platelet-activating factor increases VE-cadherin tyrosine phosphorylation in mouse endothelial cells and its association with the PtdIns3'-kinase

    PubMed Central

    Hudry-Clergeon, Hélène; Stengel, Dominique; Ninio, Ewa; Vilgrain, Isabelle

    2005-01-01

    Platelet-activating-Factor (PAF), a potent inflammatory mediator, is involved in endothelial permeability. This study was designed to characterize PAF receptor (PAF-R) expression and its specific contribution to the modifications of adherens junctions in mouse endothelial cells. We demonstrated that PAF-R was expressed in mouse endothelial cells and was functionally active in stimulating p42/p44 MAPK and phosphatidylinositol 3-kinase (PtdIns3′-kinase)/Akt activities. Treatment of cells with PAF induced a rapid, time- and dose-dependent (10−7 to 10−10M) increase in tyrosine phosphorylation of a subset of proteins ranging from 90 kDa to 220 kDa, including the VE-cadherin, the latter effect being prevented by the tyrosine kinase inhibitors, herbimycin A and bis-tyrphostin. Furthermore, we demonstrated that PAF promoted formation of multimeric aggregates of VE-cadherin with PtdIns3′-kinase which was also inhibited by herbimycin and bis-tyrphostin. Finally, we showed by immunostaining of endothelial cells VE-cadherin, that PAF dissociated adherens junctions. The present data provide the first evidence that the treatment of endothelial cells with PAF promoted activation of tyrosine kinases and the VE-cadherin tyrosine phosphorylation and PtdIns3′-kinase association, that ultimately lead to the dissociation of adherens junctions. Physical association between PtdIns3′-kinase, serving as a docking protein, and VE-cadherin may thus provide an efficient mechanism for amplification and perpetuation of PAF-induced cellular activation. PMID:15791001

  19. Mammalian cadherins DCHS1-FAT4 affect functional cerebral architecture.

    PubMed

    Beste, Christian; Ocklenburg, Sebastian; von der Hagen, Maja; Di Donato, Nataliya

    2016-06-01

    Cortical development is a complex process where a multitude of factors, including cadherins, plays an important role and where disruptions are known to have far reaching effects in neural development and cortical patterning. Cadherins play a central role in structural left-right differentiation during brain and body development, but their effect on a functional level remains elusive. We addressed this question by examining functional cerebral asymmetries in a patient with Van Maldergem Syndrome (VMS) (MIM#601390), which is caused by mutations in DCHS1-FAT4 cadherins, using a dichotic listening task. Using neurophysiological (EEG) data, we show that when key regulators during mammalian cerebral cortical development are disrupted due to DCHS1-FAT4 mutations, functional cerebral asymmetries are stronger. Basic perceptual processing of biaurally presented auditory stimuli was unaffected. This suggests that the strength and emergence of functional cerebral asymmetries is a direct function of proliferation and differentiation of neuronal stem cells. Moreover, these results support the recent assumption that the molecular mechanisms establishing early left-right differentiation are an important factor in the ontogenesis of functional lateralization. PMID:25930014

  20. Guidance Receptors in the Nervous and Cardiovascular Systems.

    PubMed

    Rubina, K A; Tkachuk, V A

    2015-10-01

    Blood vessels and nervous fibers grow in parallel, for they express similar receptors for chemokine substances. Recently, much attention is being given to studying guidance receptors and their ligands besides the growth factors, cytokines, and chemokines necessary to form structures in the nervous and vascular systems. Such guidance molecules determine trajectory for growing axons and vessels. Guidance molecules include Ephrins and their receptors, Neuropilins and Plexins as receptors for Semaphorins, Robos as receptors for Slit-proteins, and UNC5B receptors binding Netrins. Apart from these receptors and their ligands, urokinase and its receptor (uPAR) and T-cadherin are also classified as guidance molecules. The urokinase system mediates local proteolysis at the leading edge of cells, thereby providing directed migration. T-cadherin is a repellent molecule that regulates the direction of growing axons and blood vessels. Guidance receptors also play an important role in the diseases of the nervous and cardiovascular systems. PMID:26567567

  1. Hybrid GPCR/cadherin (Celsr) proteins in rat testis are expressed with cell type specificity and exhibit differential Sertoli cell-germ cell adhesion activity.

    PubMed

    Beall, Stephanie A; Boekelheide, Kim; Johnson, Kamin J

    2005-01-01

    Spermatogenesis requires Sertoli cell-germ cell adhesion for germ cell survival and maturation. Cadherins are a diverse superfamily of adhesion proteins; structurally unique members of this superfamily (celsr cadherins) are hybrid molecules containing extracellular cadherin repeats connected to a G protein-coupled receptor transmembrane motif. Here we demonstrate postnatal testicular mRNA expression of the 3 celsr paralogs (celsr1, celsr2, and celsr3), protein localization of celsr2 and celsr3, and functional analysis of celsr2 adhesion activity in primary Sertoli cell-germ cell co-cultures. Evaluation of celsr mRNA levels during a postnatal time course indicated that celsr1 and celsr2 were Sertoli cell and/or early-stage germ cell products, whereas celsr3 was expressed in later-stage germ cells. Cell type-specific expression was verified using the Sertoli cell line 93RS2, where celsr1 and celsr2 mRNA, but not celsr3, were detected. Immunostaining of testicular cryosections resulted in celsr2 protein localization to a spokelike pattern in the basal seminiferous epithelium and punctate figures in the apical epithelium, consistent with both Sertoli cell and germ cell expression. Celsr3 localized to punctate structures in the adluminal epithelium from postnatal day 40, consistent with elongate spermatid expression. The subcellular localization of celsr2 was examined further to define its localization in Sertoli cells and germ cells. Celsr2 localized to the Golgi complex in Sertoli cells and germ cells. In addition, germ cell celsr2 localized to a rab7-positive structure, which may be an endocytic compartment. Neither celsr2 nor celsr3 immunostaining was present at classic cadherin-based adhesion junctions. Nonetheless, the addition of a recombinant celsr2 protein fragment consisting of extracellular cadherin domains 4 through 8 to Sertoli cell-germ cell co-cultures resulted in germ cell detachment from Sertoli cells. Collectively, these data indicate that celsr

  2. The Extracellular Architecture of Adherens Junctions Revealed by Crystal Structures of Type I Cadherins

    SciTech Connect

    O Harrison; X Jin; S Hong; F Bahna; G Ahlsen; J Brasch; Y Wu; J Vendome; K Felsovalyi; et al.

    2011-12-31

    Adherens junctions, which play a central role in intercellular adhesion, comprise clusters of type I classical cadherins that bind via extracellular domains extended from opposing cell surfaces. We show that a molecular layer seen in crystal structures of E- and N-cadherin ectodomains reported here and in a previous C-cadherin structure corresponds to the extracellular architecture of adherens junctions. In all three ectodomain crystals, cadherins dimerize through a trans adhesive interface and are connected by a second, cis, interface. Assemblies formed by E-cadherin ectodomains coated on liposomes also appear to adopt this structure. Fluorescent imaging of junctions formed from wild-type and mutant E-cadherins in cultured cells confirm conclusions derived from structural evidence. Mutations that interfere with the trans interface ablate adhesion, whereas cis interface mutations disrupt stable junction formation. Our observations are consistent with a model for junction assembly involving strong trans and weak cis interactions localized in the ectodomain.

  3. Retrotransposon "Qian" mediated segmental duplication in silkworm, Bombyx mori.

    PubMed

    Xu, Yunmin; Jiang, Ning; Zou, Ziliang; Tu, Zhijian; Chen, Anli; Zhao, Qiaoling; Xiang, Zhonghuai; He, Ningjia

    2014-03-01

    Transposable elements constitute a large fraction of the eukaryotic genomes. They have the potential to alter genome structure and play a major role in genome evolution. Here, we report a segmental duplication mediated by a novel long terminal repeat (LTR) retrotransposon as the cause of an egg-shell recessive lethal mutant (l-em mutant) in silkworm (Bombyx mori). The segmental duplication resulted in the duplication of six genes and the disruption of two genes. Disruption of BmEP80 (B. mori egg protein 80), a gene encoding a major egg-shell structure protein, is likely responsible for the lethal water-loss phenotype in the l-em/l-em mutant. Our data revealed that BmEP80 is present in the inner egg-shell layer and plays important roles in resistance to water efflux form eggs. A novel LTR retrotransposon (named as "Qian") was identified and the model for the Qian-mediated chromosomal segmental duplication was proposed. Detail biochemical and genomic analyses on the l-em mutant offer an opportunity to demonstrate that an LTR retrotransposon could trigger duplication of a chromosomal segment (∼96.3 kb) and confer novel phenotype. PMID:24462715

  4. (1)H, (13)C and (15)N backbone assignment of the EC-1 domain of human E-cadherin.

    PubMed

    Prasasty, Vivitri D; Krause, Mary E; Tambunan, Usman S F; Anbanandam, Asokan; Laurence, Jennifer S; Siahaan, Teruna J

    2015-04-01

    The Extracellular 1 (EC1) domain of E-cadherin has been shown to be important for cadherin-cadherin homophilic interactions. Cadherins are responsible for calcium-mediated cell-cell adhesion located at the adherens junction of the biological barriers (i.e., intestinal mucosa and the blood-brain barrier (BBB)). Cadherin peptides can modulate cadherin interactions to improve drug delivery through the BBB. However, the mechanism of modulating the E-cadherin interactions by cadherin peptides has not been fully elucidated. To provide a basis for subsequent examination of the structure and peptide-binding properties of the EC1 domain of human E-cadherin using solution NMR spectroscopy, the (1)H, (13)C and (15)N backbone resonance of the uniformly labeled-EC1 were assigned and the secondary structure was determined based on the chemical shift values. These resonance assignments are essential for assessing protein-ligand interactions and are reported here. PMID:24510398

  5. Cadherin expression in gastrointestinal tract endometriosis: possible role in deep tissue invasion and development of malignancy.

    PubMed

    Van Patten, Katy; Parkash, Vinita; Jain, Dhanpat

    2010-01-01

    Cadherins are cell surface proteins crucial for cell adhesion and tissue integrity. The mechanism of deep tissue invasion in gastrointestinal endometriosis is unknown and may be related to the altered expression of these cell surface proteins. The goal of this study was to evaluate the expression of N-cadherin, E-cadherin, and beta-catenin in peritoneal endometriotic implants, gastrointestinal endometriosis, and carcinoma arising in gastrointestinal endometriosis. Cases of peritoneal endometriosis, gastrointestinal endometriosis, and carcinoma arising in gastrointestinal endometriosis were identified from our pathology database. Immunohistochemistry was performed using antibodies against N-cadherin, E-cadherin, and beta-catenin on representative tissue sections. Cases of normal proliferative and secretory endometrium and adenomyosis were included in the study for comparison. The intensity and extent of staining for each marker was scored semiquantitatively. Appropriate positive and negative controls were used. A total of 38 cases (peritoneal endometriosis (n=14), gastrointestinal endometriosis (n=21: 11 colon, 8 appendix, 2 small bowel), and 3 cases of endometrioid carcinoma arising in colonic endometriosis (n=3)) were included in the study. Compared with normal proliferative endometrium, N-cadherin expression was decreased in intensity and extent in secretory endometrium. Peritoneal and gastrointestinal endometriosis also showed markedly decreased expression of N-cadherin compared with proliferative endometrium. All three cases of carcinoma arising in colonic endometriosis showed a total loss of N-cadherin in the tumor, but preserved E-cadherin and beta-catenin expression. In these cases, areas of benign endometriotic glands near the tumor showed weak and focal N-cadherin expression that was gradually lost. Moderate-to-strong membranous staining for beta-catenin expression and variable intensity of E-cadherin expression was seen diffusely in normal endometrium and

  6. P120-Catenin Regulates Early Trafficking Stages of the N-Cadherin Precursor Complex

    PubMed Central

    Wehrendt, Diana P.; Carmona, Fernando; González Wusener, Ana E.; González, Ángela; Martínez, Juan M. Lázaro; Arregui, Carlos O.

    2016-01-01

    It is well established that binding of p120 catenin to the cytoplasmic domain of surface cadherin prevents cadherin endocytosis and degradation, contributing to cell-cell adhesion. In the present work we show that p120 catenin bound to the N-cadherin precursor, contributes to its anterograde movement from the endoplasmic reticulum (ER) to the Golgi complex. In HeLa cells, depletion of p120 expression, or blocking its binding to N-cadherin, increased the accumulation of the precursor in the ER, while it decreased the localization of mature N-cadherin at intercellular junctions. Reconstitution experiments in p120-deficient SW48 cells with all three major isoforms of p120 (1, 3 and 4) had similar capacity to promote the processing of the N-cadherin precursor to the mature form, and its localization at cell-cell junctions. P120 catenin and protein tyrosine phosphatase PTP1B facilitated the recruitment of the N-ethylmaleimide sensitive factor (NSF), an ATPase involved in vesicular trafficking, to the N-cadherin precursor complex. Dominant negative NSF E329Q impaired N-cadherin trafficking, maturation and localization at cell-cell junctions. Our results uncover a new role for p120 catenin bound to the N-cadherin precursor ensuring its trafficking through the biosynthetic pathway towards the cell surface. PMID:27254316

  7. There are four dynamically and functionally distinct populations of E-cadherin in cell junctions

    PubMed Central

    Erami, Zahra; Timpson, Paul; Yao, Wu; Zaidel-Bar, Ronen; Anderson, Kurt I.

    2015-01-01

    ABSTRACT E-cadherin is a trans-membrane tumor suppressor responsible for epithelial cell adhesion. E-cadherin forms adhesive clusters through combined extra-cellular cis- and trans-interactions and intracellular interaction with the actin cytoskeleton. Here we identify four populations of E-cadherin within cell junctions based on the molecular interactions which determine their mobility and adhesive properties. Adhesive and non-adhesive populations of E-cadherin each consist of mobile and immobile fractions. Up to half of the E-cadherin immobilized in cell junctions is non-adhesive. Incorporation of E-cadherin into functional adhesions require all three adhesive interactions, with deletion of any one resulting in loss of effective cell-cell adhesion. Interestingly, the only interaction which could independently slow the diffusion of E-cadherin was the tail-mediated intra-cellular interaction. The adhesive and non-adhesive mobile fractions of E-cadherin can be distinguished by their sensitivity to chemical cross-linking with adhesive clusters. Our data define the size, mobility, and adhesive properties of four distinct populations of E-cadherin within cell junctions, and support association with the actin cytoskeleton as the first step in adhesion formation. PMID:26471767

  8. Rac1 functions as a reversible tension modulator to stabilize VE-cadherin trans-interaction.

    PubMed

    Daneshjou, Nazila; Sieracki, Nathan; van Nieuw Amerongen, Geerten P; Schwartz, Martin A; Komarova, Yulia A; Malik, Asrar B; Conway, Daniel E

    2015-01-01

    The role of the RhoGTPase Rac1 in stabilizing mature endothelial adherens junctions (AJs) is not well understood. In this paper, using a photoactivatable probe to control Rac1 activity at AJs, we addressed the relationship between Rac1 and the dynamics of vascular endothelial cadherin (VE-cadherin). We demonstrated that Rac1 activation reduced the rate of VE-cadherin dissociation, leading to increased density of VE-cadherin at AJs. This response was coupled to a reduction in actomyosin-dependent tension across VE-cadherin adhesion sites. We observed that inhibiting myosin II directly or through photo-release of the caged Rho kinase inhibitor also reduced the rate of VE-cadherin dissociation. Thus, Rac1 functions by stabilizing VE-cadherin trans-dimers in mature AJs by counteracting the actomyosin tension. The results suggest a new model of VE-cadherin adhesive interaction mediated by Rac1-induced reduction of mechanical tension at AJs, resulting in the stabilization of VE-cadherin adhesions. PMID:25559184

  9. Transcriptional Repression of E-Cadherin by Human Papillomavirus Type 16 E6

    PubMed Central

    D'Costa, Zarina J.; Jolly, Carol; Androphy, Elliot J.; Mercer, Andrew; Matthews, Charles M.; Hibma, Merilyn H.

    2012-01-01

    There is increasing evidence supporting DNA virus regulation of the cell adhesion and tumour suppressor protein, E-cadherin. We previously reported that loss of E-cadherin in human papillomavirus (HPV) type 16-infected epidermis is contributed to by the major viral proto-oncogene E6 and is associated with reduced Langerhans cells density, potentially regulating the immune response. The focus of this study is determining how the HPV16 E6 protein mediates E-cadherin repression. We found that the E-cadherin promoter is repressed in cells expressing E6, resulting in fewer E-cadherin transcripts. On exploring the mechanism for this, repression by increased histone deacetylase activity or by increased binding of trans-repressors to the E-cadherin promoter Epal element was discounted. In contrast, DNA methyltransferase (DNMT) activity was increased in E6 expressing cells. Upon inhibiting DNMT activity using 5-Aza-2′-deoxycytidine, E-cadherin transcription was restored in the presence of HPV16 E6. The E-cadherin promoter was not directly methylated, however a mutational analysis showed general promoter repression and reduced binding of the transactivators Sp1 and AML1 and the repressor Slug. Expression of E7 with E6 resulted in a further reduction in surface E-cadherin levels. This is the first report of HPV16 E6-mediated transcriptional repression of this adhesion molecule and tumour suppressor protein. PMID:23189137

  10. There are four dynamically and functionally distinct populations of E-cadherin in cell junctions.

    PubMed

    Erami, Zahra; Timpson, Paul; Yao, Wu; Zaidel-Bar, Ronen; Anderson, Kurt I

    2015-01-01

    E-cadherin is a trans-membrane tumor suppressor responsible for epithelial cell adhesion. E-cadherin forms adhesive clusters through combined extra-cellular cis- and trans-interactions and intracellular interaction with the actin cytoskeleton. Here we identify four populations of E-cadherin within cell junctions based on the molecular interactions which determine their mobility and adhesive properties. Adhesive and non-adhesive populations of E-cadherin each consist of mobile and immobile fractions. Up to half of the E-cadherin immobilized in cell junctions is non-adhesive. Incorporation of E-cadherin into functional adhesions require all three adhesive interactions, with deletion of any one resulting in loss of effective cell-cell adhesion. Interestingly, the only interaction which could independently slow the diffusion of E-cadherin was the tail-mediated intra-cellular interaction. The adhesive and non-adhesive mobile fractions of E-cadherin can be distinguished by their sensitivity to chemical cross-linking with adhesive clusters. Our data define the size, mobility, and adhesive properties of four distinct populations of E-cadherin within cell junctions, and support association with the actin cytoskeleton as the first step in adhesion formation. PMID:26471767

  11. Lateral assembly of N-cadherin drives tissue integrity by stabilizing adherens junctions

    PubMed Central

    Garg, S.; Fischer, S. C.; Schuman, E. M.; Stelzer, E. H. K.

    2015-01-01

    Cadherin interactions ensure the correct registry and anchorage of cells during tissue formation. Along the plasma membrane, cadherins form inter-junctional lattices via cis- and trans-dimerization. While structural studies have provided models for cadherin interactions, the molecular nature of cadherin binding in vivo remains unexplored. We undertook a multi-disciplinary approach combining live cell imaging of three-dimensional cell assemblies (spheroids) with a computational model to study the dynamics of N-cadherin interactions. Using a loss-of-function strategy, we demonstrate that each N-cadherin interface plays a distinct role in spheroid formation. We found that cis-dimerization is not a prerequisite for trans-interactions, but rather modulates trans-interfaces to ensure tissue stability. Using a model of N-cadherin junction dynamics, we show that the absence of cis-interactions results in low junction stability and loss of tissue integrity. By quantifying the binding and unbinding dynamics of the N-cadherin binding interfaces, we determined that mutating either interface results in a 10-fold increase in the dissociation constant. These findings provide new quantitative information on the steps driving cadherin intercellular adhesion and demonstrate the role of cis-interactions in junction stability. PMID:25589573

  12. Cadherin adhesion depends on a salt bridge at the N-terminus.

    PubMed

    Harrison, Oliver J; Corps, Elaine M; Kilshaw, Peter J

    2005-09-15

    There is now considerable evidence that cell adhesion by cadherins requires a strand exchange process in which the second amino acid at the N-terminus of the cadherin molecule, Trp2, docks into a hydrophobic pocket in the domain fold of the opposing cadherin. Here we show that strand exchange depends on a salt bridge formed between the N-terminal amino group of one cadherin molecule and the acidic side chain of Glu89 of the other. Prevention of this bond in N-cadherin by introducing the mutation Glu89Ala or by extending the N-terminus with additional amino acids strongly inhibited strand exchange. But when the two modifications were present in opposing cadherin molecules respectively, they acted in a complementary manner, lowering activation energy for strand exchange and greatly increasing the strength of the adhesive interaction. N-cadherin that retained an uncleaved prodomain or lacked Trp2 adhered strongly to the Glu89Ala mutant but not to wild-type molecules. Similarly, N-cadherin in which the hydrophobic acceptor pocket was blocked by an isoleucine side chain adhered to a partner that had an extended N-terminus. We explain these results in terms of the free energy changes that accompany strand exchange. Our findings provide new insight into the mechanism of adhesion and demonstrate the feasibility of greatly increasing cadherin affinity. PMID:16118243

  13. Hypoxia induced E-cadherin involving regulators of Hippo pathway due to HIF-1α stabilization/nuclear translocation in bone metastasis from breast carcinoma

    SciTech Connect

    Maroni, Paola; Matteucci, Emanuela; Drago, Lorenzo; Banfi, Giuseppe; Bendinelli, Paola; Desiderio, Maria Alfonsina

    2015-01-15

    The present study deals with the molecular mechanisms involved in the regulation of E-cadherin expression under hypoxia, because the adjustment of the amount of E-cadherin due to physical stimuli of the microenvironment might influence the colonization of metastasis to skeleton. We analyzed the effect of 1% oxygen tension, that is similar to that encountered in the bone marrow by metastatic cells spreading from breast carcinoma. The purpose was to evaluate the hypoxia-orchestrated control of E-cadherin transactivation via hypoxia inducible factor-1 (HIF-1) and peroxisome proliferator activated receptor-γ (PPARγ), and the involvement of Hippo pathway members, as regulators of transcription factors. To give a translational significance to the study, we took into consideration human pair-matched ductal breast carcinoma and bone metastasis: E-cadherin and Wwox were expressed in bone metastasis but not in breast carcinoma, while HIF-1α and TAZ seemed localized principally in nuclei of metastasis and were found in all cell compartments of breast carcinoma. A close examination of the regulatory mechanisms underlying E-cadherin expression in bone metastasis was done in 1833 clone derived from MDA-MB231 cells. Hypoxia induced E-cadherin only in 1833 clone, but not in parental cells, through HIF-1 and PPARγ activities, while Wwox decreased. Since Wwox was highly expressed in bone metastasis, the effect of ectopic Wwox was evaluated, and we showed E-cadherin transactivation and enhanced invasiveness in WWOX transfected 1833 cells. Also, hypoxia was additive with ectopic Wwox remarkably enhancing HIF-1α nuclear shuttle and accumulation due to the lengthening of the half-life of HIF-1α protein; under this experimental condition HIF-1α appeared as a slower migrated band compared with control, in agreement with the phosphorylation state. The in vitro data strongly supported the almost exclusive presence of HIF-1α in nuclei of human-bone metastasis. Thus, we identified

  14. Mori Folium and Mori Fructus Mixture Attenuates High-Fat Diet-Induced Cognitive Deficits in Mice

    PubMed Central

    Jeong, Hyun Uk; Park, Gunhyuk; Kim, Hocheol; Lim, Yunsook; Oh, Myung Sook

    2015-01-01

    Obesity has become a global health problem, contributing to various diseases including diabetes, hypertension, cancer, and dementia. Increasing evidence suggests that obesity can also cause neuronal damage, long-term memory loss, and cognitive impairment. The leaves and the fruits of Morus alba L., containing active phytochemicals, have been shown to possess antiobesity and hypolipidemic properties. Thus, in the present study, we assessed their effects on cognitive functioning in mice fed a high-fat diet by performing immunohistochemistry, using antibodies against c-Fos, synaptophysin, and postsynaptic density protein 95 and a behavioral test. C57BL/6 mice fed a high-fat diet for 21 weeks exhibited increased body weight, but mice coadministered an optimized Mori Folium and Mori Fructus extract mixture (2 : 1; MFE) for the final 12 weeks exhibited significant body weight loss. Additionally, obese mice exhibited not only reduced neural activity, but also decreased presynaptic and postsynaptic activities, while MFE-treated mice exhibited recovery of these activities. Finally, cognitive deficits induced by the high-fat diet were recovered by cotreatment with MFE in the novel object recognition test. Our findings suggest that the antiobesity effects of MFE resulted in recovery of the cognitive deficits induced by the high-fat diet by regulation of neural and synaptic activities. PMID:25945108

  15. Expression of RYamide in the nervous and endocrine system of Bombyx mori.

    PubMed

    Roller, Ladislav; Čižmár, Daniel; Bednár, Branislav; Žitňan, Dušan

    2016-06-01

    RYamides are neuropeptides encoded by a gene whose precise expression and function have not yet been determined. We identified the RYamide gene transcript (fmgV1g15f, SilkBase database) and predicted two candidates for G-protein coupled RYamide receptors (A19-BAG68418 and A22-BAG68421) in the silkworm Bombyx mori. We cloned the RYamide transcript and described its spatial expression using in situ hybridisation. In the larval central nervous system (CNS) expression of RYamide was restricted to 12-14 small neurons in the brain and two posterior neurons in the terminal abdominal ganglion. During metamorphosis their number decreased to eight protocerebral neurons in the adults. Multiple staining, using various insect neuropeptide antibodies, revealed that neurons expressing RYamide are different from other peptidergic cells in the CNS. We also found RYamide expression in the enteroendocrine cells (EC) of the anterior midgut of larvae, pupae and adults. Two minor subpopulations of these EC were also immunoreactive to antibodies against tachykinin and myosupressin. This expression pattern suggests RYamides may play a role in the regulation of feeding and digestion. PMID:26896568

  16. Adenylate cyclase in prothoracic glands during the last larval instar of the silkworm, Bombyx mori.

    PubMed

    Chen, C H; Gu, S H; Chow, Y S

    2001-04-27

    We have previously reported that the absence of prothoracicotropic hormone (PTTH) signal transduction during the early last larval instar of Bombyx mori plays a role in leading to very low ecdysteroid levels in the hemolymph, inactivation of the corpora allata, as well as larval-pupal transformation. In the present study, adenylate cyclase was characterized in crude preparations of prothoracic gland cell membranes in an effort to localize the cause of refractoriness to PTTH. It was found that cyclase activity of the prothoracic glands from the day 6 last instar showed activation responses to fluoride, a guanine nucleotide analogue, as well as calmodulin (CaM) in dose-dependent fashions. The additive effects of day 5 prothoracic gland adenylate cyclase stimulation by fluoride and CaM imply that there may exist Gs protein-dependent and CaM-dependent forms of adenylate cyclase. For day 1 last instar prothoracic glands, which showed no response to stimulation by PTTH in either cAMP generation or ecdysteroidogenesis, adenylate cyclase activity exhibited far less responsiveness to Ca(2+)/CaM than did that from day 5 glands. These findings suggest that day 1 prothoracic glands may possess some lesions in the receptor-Ca(2+) influx-adenylate cyclase signal transduction pathway and these impairments in PTTH signal transduction may be, at least in part, responsible for decreased ecdysteroidogenesis. PMID:11267904

  17. Characterization of a dual-CRD galectin in the silkworm Bombyx mori.

    PubMed

    Rao, Xiang-Jun; Wu, Peng; Shahzad, Toufeeq; Liu, Su; Chen, Ling; Yang, Yun-Fan; Shi, Qiao; Yu, Xiao-Qiang

    2016-07-01

    Galectins (S-type lectins) are an ancient family of lectins with the β-galactoside binding activity. In mammals, galectins play essential roles in many biological processes, such as development, immune homeostasis and tumor progression. However, few studies have been devoted to their functions in insects. Here, we characterized the only dual-CRD galectin in the silkworm Bombyx mori (BmGalectin-4). BmGalectin-4 cDNA possesses an open reading frame of 1089 bp, which encodes a putative galectin of 363 amino acids containing tandem carbohydrate recognition domains (CRDs). BmGalectin-4 was expressed in various tissues but the protein was most abundant in fertilized eggs. Its transcript level in fertilized eggs was upregulated upon bacterial challenge. Recombinant BmGalectin-4 purified from Escherichia coli bound to bacterial cell wall components and bacterial cells. In addition, the recombinant protein induced bacterial agglutination, but did not have antibacterial activity against selected microorganisms. Taken together, our results suggest that BmGalectin-4 may function as a pattern recognition receptor primarily in silkworm fertilized eggs. PMID:26944801

  18. Control of the collective migration of enteric neural crest cells by the Complement anaphylatoxin C3a and N-cadherin.

    PubMed

    Broders-Bondon, Florence; Paul-Gilloteaux, Perrine; Gazquez, Elodie; Heysch, Julie; Piel, Matthieu; Mayor, Roberto; Lambris, John D; Dufour, Sylvie

    2016-06-01

    We analyzed the cellular and molecular mechanisms governing the adhesive and migratory behavior of enteric neural crest cells (ENCCs) during their collective migration within the developing mouse gut. We aimed to decipher the role of the complement anaphylatoxin C3a during this process, because this well-known immune system attractant has been implicated in cephalic NCC co-attraction, a process controlling directional migration. We used the conditional Ht-PA-cre transgenic mouse model allowing a specific ablation of the N-cadherin gene and the expression of a fluorescent reporter in migratory ENCCs without affecting the central nervous system. We performed time-lapse videomicroscopy of ENCCs from control and N-cadherin mutant gut explants cultured on fibronectin (FN) and micropatterned FN-stripes with C3a or C3aR antagonist, and studied cell migration behavior with the use of triangulation analysis to quantify cell dispersion. We performed ex vivo gut cultures with or without C3aR antagonist to determine the effect on ENCC behavior. Confocal microscopy was used to analyze the cell-matrix adhesion properties. We provide the first demonstration of the localization of the complement anaphylatoxin C3a and its receptor on ENCCs during their migration in the embryonic gut. C3aR receptor inhibition alters ENCC adhesion and migration, perturbing directionality and increasing cell dispersion both in vitro and ex vivo. N-cadherin-null ENCCs do not respond to C3a co-attraction. These findings indicate that C3a regulates cell migration in a N-cadherin-dependent process. Our results shed light on the role of C3a in regulating collective and directional cell migration, and in ganglia network organization during enteric nervous system ontogenesis. The detection of an immune system chemokine in ENCCs during ENS development may also shed light on new mechanisms for gastrointestinal disorders. PMID:27041467

  19. A novel amphioxus cadherin that localizes to epithelial adherens junctions has an unusual domain organization with implications for chordate phylogeny.

    PubMed

    Oda, Hiroki; Wada, Hiroshi; Tagawa, Kunifumi; Akiyama-Oda, Yasuko; Satoh, Nori; Humphreys, Tom; Zhang, Shicui; Tsukita, Shoichiro

    2002-01-01

    Although data are available from only vertebrates, urochordates, and three nonchordate animals, there are definite differences in the structures of classic cadherins between vertebrates plus urochordates and nonchordates. In this study we examined structural diversity of classic cadherins among bilaterian animals by obtaining new data from an amphioxus (Cephalochordata, Chordata), an acorn worm (Hemichordata), a sea star (Echinodermata), and an oyster (Mollusca). The structures of newly identified nonchordate cadherins are grouped together with those of the known sea urchin and Drosophila cadherins, whereas the structure of an amphioxus (Branchiostoma belcheri) cadherin, designated BbC, is differently categorized from those of other known chordate cadherins. BbC is identified as a cadherin by its cytoplasmic domain whose sequence is highly related to the cytoplasmic sequences of all known classic cadherins, but it lacks all of the five repeats constituting the extracellular homophilic-binding domain of other chordate cadherins. The ectodomains of BbC match the ectodomains found in nonchordate cadherins but not present in other chordate cadherins. We show that the BbC functions as a cell-cell adhesion molecule when expressed in Drosophila S2 cells and localizes to adherens junctions in the ectodermal epithelia in amphioxus embryos. We argue that BbC is the amphioxus homologue of the classic cadherins involved in the formation of epithelial adherens junctions. The structural relationships of the cadherin molecules allow us to propose a possibility that cephalochordates might be basal to the sister-groups vertebrates and urochordates. PMID:12492143

  20. N-cadherin-catenin complexes form prior to cleavage of the proregion and transport to the plasma membrane.

    PubMed

    Wahl, James K; Kim, Young J; Cullen, Janet M; Johnson, Keith R; Wheelock, Margaret J

    2003-05-01

    Cadherins are calcium-dependent glycoproteins that function as cell-cell adhesion molecules and are linked to the actin cytoskeleton via catenins. Newly synthesized cadherins contain a prosequence that must be proteolytically removed to generate a functional adhesion molecule. The goal of this study was to examine the proteolytic processing of N-cadherin and the assembly of the cadherin-catenin complex in cells that express endogenous N-cadherin. A monoclonal antibody specific for the proregion of human N-cadherin was generated and used to examine N-cadherin processing. Our data show that newly synthesized proN-cadherin is phosphorylated and proteolytically processed prior to transport to the plasma membrane. In addition, we show that beta-catenin and plakoglobin associate only with phosphorylated proN-cadherin, whereas p120(ctn) can associate with both phosphorylated and non-phosphorylated proN-cadherin. Immunoprecipitations using anti-proN-cadherin showed that cadherin-catenin complexes are assembled prior to localization at the plasma membrane. These data suggest that a core N-cadherin-catenin complex assembles in the endoplasmic reticulum or Golgi compartment and is transported to the plasma membrane where linkage to the actin cytoskeleton can be established. PMID:12604612

  1. The clinicopathological significance and potential drug target of E-cadherin in NSCLC.

    PubMed

    Zhong, Kaize; Chen, Weiwen; Xiao, Ning; Zhao, Jian

    2015-08-01

    Human epithelial cadherin (E-cadherin), a member of transmembrane glycoprotein family, encoded by the E-cadherin gene, plays a key role in cell-cell adhesion, adherent junction in normal epithelial tissues, contributing to tissue differentiation and homeostasis. Although previous studies indicated that inactivation of the E-cadherin is mainly induced by hypermethylation of E-cadherin gene, evidence concerning E-cadherin hypermethylation in the carcinogenesis and development of non-small cell lung carcinoma (NSCLC) remains controversial. In this study, we conducted a meta-analysis to quantitatively evaluate the effects of E-cadherin hypermethylation on the incidence and clinicopathological characteristics of NSCLC. A comprehensive search of PubMed and Embase databases was performed up to October 2014. Analyses of pooled data were performed. Odds ratios (ORs) were calculated and summarized. Our meta-analysis combining 18 published articles demonstrated that the hypermethylation frequencies in NSCLC were significantly higher than those in normal control tissues, OR = 3.55, 95 % confidence interval (CI) = 1.98-6.36, p < 0.0001. Further analysis showed that E-cadherin hypermethylation was not strongly associated with the sex or smoking status in NSCLC patients. In addition, E-cadherin hypermethylation was also not strongly associated with pathological types, differentiated status, clinical stages, or metastatic status in NSCLC patients. The results from the current study indicate that the hypermethylation frequency of E-cadherin in NSCLC is strongly associated with NSCLC incidence and it may be an early event in carcinogenesis of NSCLC. We also discussed the potential value of E-cadherin as a drug target that may bring new direction and hope for cancer treatment through gene-targeted therapy. PMID:25758052

  2. E-cadherin and Src associate with extradesmosomal Dsg3 and modulate desmosome assembly and adhesion.

    PubMed

    Rötzer, Vera; Hartlieb, Eva; Vielmuth, Franziska; Gliem, Martin; Spindler, Volker; Waschke, Jens

    2015-12-01

    Desmosomes provide strong intercellular cohesion essential for the integrity of cells and tissues exposed to continuous mechanical stress. For desmosome assembly, constitutively synthesized desmosomal cadherins translocate to the cell-cell border, cluster and mature in the presence of Ca(2+) to stable cell contacts. As adherens junctions precede the formation of desmosomes, we investigated in this study the relationship between the classical cadherin E-cadherin and the desmosomal cadherin Desmoglein 3 (Dsg3), the latter of which is indispensable for cell-cell adhesion in keratinocytes. By using autoantibodies from patients with the blistering skin disease pemphigus vulgaris (PV), we showed in loss of function studies that E-cadherin compensates for effects of desmosomal disassembly. Overexpression of E-cadherin reduced the loss of cell cohesion induced by PV autoantibodies and attenuated activation of p38 MAPK. Silencing of E-cadherin abolished the localization of Dsg3 at the membrane and resulted in a shift of Dsg3 from the cytoskeletal to the non-cytoskeletal protein pool which conforms to the notion that E-cadherin regulates desmosome assembly. Mechanistically, we identified a complex consisting of extradesmosomal Dsg3, E-cadherin, β-catenin and Src and that the stability of this complex is regulated by Src. Moreover, Dsg3 and E-cadherin are phosphorylated on tyrosine residues in a Src-dependent manner and Src activity is required for recruiting Dsg3 to the cytoskeletal pool as well as for desmosome maturation towards a Ca(2+)-insensitive state. Our data provide new insights into the role of E-cadherin and the contribution of Src signaling for formation and maintenance of desmosomal junctions. PMID:26115704

  3. Numerical simulation of the Mori geothermal field, JP

    SciTech Connect

    Yukihiro Sakagawa; Masahiro Takahashi; Mineyuki Hanano; Tsuneo Ishido; Nobuhiro Demboya

    1994-01-20

    A numerical study of the Mori geothermal field which consisted of a series of three-dimensional natural state modeling and history matching was carried out with porous models. Finally satisfactory fits both on temperature and pressure of the natural state and on pressure history caused by exploitation were obtained. The results indicate that the deep hot water ascends mainly through the fractures near the caldera wall and the fractures confined to some lithofaces, and some of the ascending hot water flows to the west from the caldera. A sketch of the geological structure, the way of making up the initial numerical model, the way of concluding free parameters, and results of calculations of natural state modeling and history matching for the best numerical model are presented.

  4. Investigation of Natural Bombyx mori Silk Fibroin Proteins Using INS

    NASA Astrophysics Data System (ADS)

    Crain, Christopher; Strange, Nicholas; Larese, J. Z.

    The mechanical properties of many protein comprised biomaterials are a direct reflection of non-covalent (i.e. weak) interacting ions such as F-actin in muscles, tubulin in the cytoskeleton of cells, viral capsids, and silk. Porter and Vollrath underscored the two main factors that are critical for understanding the high mechanical strength of silks: the nanoscale semi-crystalline folding structure, which gives it exceptional toughness and strength, and the degree of hydration of the disordered fraction, which acts to modify these properties. Understanding and controlling these two principal factors are the key to the functionality of protein elastomers, and render silk an ideal model protein for (bio)material design. We will describe our investigation of electrospun silk of the Bombyx mori (silk worm), using Inelastic Neutron Scattering (INS). These techniques were used to investigate the microscopic dynamics of the dry and hydrated protein.

  5. Immunolocalization of prophenoloxidase among hemocytes of the silkworm, Bombyx mori.

    PubMed

    Ashida, M; Ochiai, M; Niki, T

    1988-01-01

    Silkworm (Bombyx mori) hemocytes were fixed immediately after collection. Thin sections of the hemocytes were stained by an indirect immunogold staining method using rabbit anti-prophenoloxidase/IgG as a primary antibody and colloidal gold coated with goat anti-rabbit/IgG as a secondary antibody. Electron micrographs of the sections revealed that only plasmatocytes and oenocytoids have prophenoloxidase both in cytoplasm and nucleus whereas granulocytes, spherulocytes and prohemocytes do not have appreciable amounts of the proenzyme. Cytoplasmic inclusions of oenocytoids also contain the proenzyme. A wide variety of concentrations of prophenoloxidase was observed among oenocytoids. Plasmatocytes appeared to have less prophenoloxidase than any oenocytoids. Once materials in the granules of granulocyte were discharged into the plasma and formed coagula, they cross-reacted with antiprophenoloxidase/IgG, suggesting that prophenoloxidase was trapped in the coagula by unknown mechanisms. This observation is discussed in relation to the dispute concerning the presence of prophenoloxidase or phenoloxidase in the granulocyte. PMID:18620238

  6. Anti-diabetic effect mediated by Ramulus mori polysaccharides.

    PubMed

    Xu, Lingyuan; Yang, Fenglian; Wang, Junli; Huang, Hao; Huang, Yanqiang

    2015-03-01

    Diabetes mellitus is a complicated metabolic disease, whose pathogenesis is related to apoptosis within pancreatic tissue. In this study, the potential therapeutic benefits of Ramulus mori polysaccharides (RMP) on streptozotocin (STZ)-induced diabetic mice were evaluated. Our experiments indicated that RMP lowered hyperglycemia and increased insulin levels in diabetic mice. Histopathological examination revealed that RMP contributed to the reduction of STZ-lesioned pancreatic cells. In addition, the serum level of HbA1c was decreased. RMP treatment also showed increased Bcl-2 expression and reduced Bax protein level in pancreatic tissue. Furthermore, intrapancreatic expressions of p-JNK, p-p38 and cleaved-caspase-3 were down-regulated by RMP treatment. Collectively, the findings demonstrate that RMP exerts the pronounced hypoglycemic effect via regulation of the intrapancreatic JNK/p38 pathway to protect against STZ-induced apoptosis in pancreatic tissue, eventually ameliorating metabolic function in the pancreas. PMID:25498609

  7. Synergistic action of nectins and cadherins generates the mosaic cellular pattern of the olfactory epithelium

    PubMed Central

    Katsunuma, Sayaka; Honda, Hisao; Shinoda, Tomoyasu; Ishimoto, Yukitaka; Miyata, Takaki; Kiyonari, Hiroshi; Abe, Takaya; Nibu, Ken-ichi; Takai, Yoshimi

    2016-01-01

    In the olfactory epithelium (OE), olfactory cells (OCs) and supporting cells (SCs), which express different cadherins, are arranged in a characteristic mosaic pattern in which OCs are enclosed by SCs. However, the mechanism underlying this cellular patterning is unclear. Here, we show that the cellular pattern of the OE is established by cellular rearrangements during development. In the OE, OCs express nectin-2 and N-cadherin, and SCs express nectin-2, nectin-3, E-cadherin, and N-cadherin. Heterophilic trans-interaction between nectin-2 on OCs and nectin-3 on SCs preferentially recruits cadherin via α-catenin to heterotypic junctions, and the differential distributions of cadherins between junctions promote cellular intercalations, resulting in the formation of the mosaic pattern. These observations are confirmed by model cell systems, and various cellular patterns are generated by the combinatorial expression of nectins and cadherins. Collectively, the synergistic action of nectins and cadherins generates mosaic pattern, which cannot be achieved by a single mechanism. PMID:26929452

  8. Three mechanisms control E-cadherin localization to the zonula adherens.

    PubMed

    Woichansky, Innokenty; Beretta, Carlo Antonio; Berns, Nicola; Riechmann, Veit

    2016-01-01

    E-cadherin localization to the zonula adherens is fundamental for epithelial differentiation but the mechanisms controlling localization are unclear. Using the Drosophila follicular epithelium we genetically dissect E-cadherin transport in an in vivo model. We distinguish three mechanisms mediating E-cadherin accumulation at the zonula adherens. Two membrane trafficking pathways deliver newly synthesized E-cadherin to the plasma membrane. One is Rab11 dependent and targets E-cadherin directly to the zonula adherens, while the other transports E-cadherin to the lateral membrane. Lateral E-cadherin reaches the zonula adherens by endocytosis and targeted recycling. We show that this pathway is dependent on RabX1, which provides a functional link between early and recycling endosomes. Moreover, we show that lateral E-cadherin is transported to the zonula adherens by an apically directed flow within the plasma membrane. Differential activation of these pathways could facilitate cell shape changes during morphogenesis, while their misregulation compromises cell adhesion and tissue architecture in differentiated epithelia. PMID:26960923

  9. Expression of connexin 43 and E-cadherin in choroidal melanoma

    PubMed Central

    Mou, Ying-Ying; Zhao, Gui-Qiu; Lin, Jin-Yong; Zhao, Jie; Lin, Hong; Hu, Li-Ting; Xu, Qiang; Wang 1, Qing; Sun, Wei-Rong

    2011-01-01

    AIM To investigate the expression of connexin 43 and epithelial cadherin (E-cadherin) in choroidal melanoma, to explore the clinical and pathological implications of expression of these proteins, and to determine their relations with malignant features. METHODS The expression of connexin 43 and E-cadherin in choroidal melanoma were detected by immunohistochemistry and correlated with clinicopathological features. RESULTS Positive rates of connexin 43 in choroidal melanomas and benign pigmented nevus tissues were 75% and 40% respectively with significant differences between the two groups (χ2=5.607, P=0.009). Positive rates of E-cadherin in choroidal melanomas and benign pigmented nevus tissues were 40% and 75% respectively with significant differences between the two groups (χ2=5.214, P=0.010). Significant overexpression of connexin 43 and reduction of E-cadherin expression was associated with the invasion to the sclera, and there were respectively significant differences between without and with scleral invasion groups (χ2=2.880, P=0.040; χ2=2.778, P=0.046). Overexpression of connexin 43 were correlated with tumor cell types and the expression of connexin 43 and E-cadherin may be correlated with each other. CONCLUSION The increased expression of connexin 43 and the decreased expression of E-cadherin may be involved in the process of invasion of choroidal melanoma. The overepression of connexin 43 and reduction of E-cadherin may contribute to the development of choroidal melanoma. PMID:22553632

  10. Rab35 regulates cadherin-mediated adherens junction formation and myoblast fusion

    PubMed Central

    Charrasse, Sophie; Comunale, Franck; De Rossi, Sylvain; Echard, Arnaud; Gauthier-Rouvière, Cécile

    2013-01-01

    Cadherins are homophilic cell–cell adhesion molecules implicated in many fundamental processes, such as morphogenesis, cell growth, and differentiation. They accumulate at cell–cell contact sites and assemble into large macromolecular complexes named adherens junctions (AJs). Cadherin targeting and function are regulated by various cellular processes, many players of which remain to be uncovered. Here we identify the small GTPase Rab35 as a new regulator of cadherin trafficking and stabilization at cell–cell contacts in C2C12 myoblasts and HeLa cells. We find that Rab35 accumulates at cell–cell contacts in a cadherin-dependent manner. Knockdown of Rab35 or expression of a dominant-negative form of Rab35 impaired N- and M-cadherin recruitment to cell–cell contacts, their stabilization at the plasma membrane, and association with p120 catenin and led to their accumulation in transferrin-, clathrin-, and AP-2–positive intracellular vesicles. We also find that Rab35 function is required for PIP5KIγ accumulation at cell–cell contacts and phosphatidyl inositol 4,5-bisphosphate production, which is involved in cadherin stabilization at contact sites. Finally, we show that Rab35 regulates myoblast fusion, a major cellular process under the control of cadherin-dependent signaling. Taken together, these results reveal that Rab35 regulates cadherin-dependent AJ formation and myoblast fusion. PMID:23197472

  11. P-cadherin promotes collective cell migration via a Cdc42-mediated increase in mechanical forces.

    PubMed

    Plutoni, Cédric; Bazellieres, Elsa; Le Borgne-Rochet, Maïlys; Comunale, Franck; Brugues, Agusti; Séveno, Martial; Planchon, Damien; Thuault, Sylvie; Morin, Nathalie; Bodin, Stéphane; Trepat, Xavier; Gauthier-Rouvière, Cécile

    2016-01-18

    Collective cell migration (CCM) is essential for organism development, wound healing, and metastatic transition, the primary cause of cancer-related death, and it involves cell-cell adhesion molecules of the cadherin family. Increased P-cadherin expression levels are correlated with tumor aggressiveness in carcinoma and aggressive sarcoma; however, how P-cadherin promotes tumor malignancy remains unknown. Here, using integrated cell biology and biophysical approaches, we determined that P-cadherin specifically induces polarization and CCM through an increase in the strength and anisotropy of mechanical forces. We show that this mechanical regulation is mediated by the P-cadherin/β-PIX/Cdc42 axis; P-cadherin specifically activates Cdc42 through β-PIX, which is specifically recruited at cell-cell contacts upon CCM. This mechanism of cell polarization and migration is absent in cells expressing E- or R-cadherin. Thus, we identify a specific role of P-cadherin through β-PIX-mediated Cdc42 activation in the regulation of cell polarity and force anisotropy that drives CCM. PMID:26783302

  12. P-cadherin promotes collective cell migration via a Cdc42-mediated increase in mechanical forces

    PubMed Central

    Plutoni, Cédric; Bazellieres, Elsa; Le Borgne-Rochet, Maïlys; Comunale, Franck; Brugues, Agusti; Séveno, Martial; Planchon, Damien; Thuault, Sylvie; Morin, Nathalie; Bodin, Stéphane; Trepat, Xavier

    2016-01-01

    Collective cell migration (CCM) is essential for organism development, wound healing, and metastatic transition, the primary cause of cancer-related death, and it involves cell–cell adhesion molecules of the cadherin family. Increased P-cadherin expression levels are correlated with tumor aggressiveness in carcinoma and aggressive sarcoma; however, how P-cadherin promotes tumor malignancy remains unknown. Here, using integrated cell biology and biophysical approaches, we determined that P-cadherin specifically induces polarization and CCM through an increase in the strength and anisotropy of mechanical forces. We show that this mechanical regulation is mediated by the P-cadherin/β-PIX/Cdc42 axis; P-cadherin specifically activates Cdc42 through β-PIX, which is specifically recruited at cell–cell contacts upon CCM. This mechanism of cell polarization and migration is absent in cells expressing E- or R-cadherin. Thus, we identify a specific role of P-cadherin through β-PIX–mediated Cdc42 activation in the regulation of cell polarity and force anisotropy that drives CCM. PMID:26783302

  13. Increased serum levels of soluble vascular endothelial-cadherin in patients with systemic vasculitis.

    PubMed

    Chen, Tao; Guo, Zai-Pei; Cao, Na; Qin, Sha; Li, Meng-Meng; Jia, Rui-Zhen

    2014-08-01

    Henoch-Schönlein purpura (HSP) is a commonest systemic vasculitis (SV) in childhood characterized by an inflammatory reaction directed at vessels. Endothelial damage and perivascular leukocyte infiltrates are vital in the development of HSP. Vascular endothelial (VE)-cadherin is an endothelial cell-specific adhesion molecule, which plays critical roles in angiogenesis and endothelial integrity. Herein, we investigated the serum levels of soluble VE-cadherin (sVE-cadherin) in patients with HSP and other forms of SV. The serum levels of sVE-cadherin in 30 patients with HSP, together with patients with urticarial vasculitis, allergic vasculitis, Behcet disease, psoriasis vulgaris (PV) and atopic dermatitis (AD) and 26 health controls were measured by enzyme-linked immunosorbent assay. Serum levels of sVE-cadherin were significantly increased in patients with HSP in acute stage and patients with other forms of SV but not in patients with PV or AD. Moreover, Serum sVE-cadherin levels in HSP patients were correlated with the severity of this disease and serum concentrations of IgA anticardiolipin antibodies and vascular endothelial growth factor. Taken together, we show firstly that serum sVE-cadherin is abnormally increased in HSP patients. Increased serum levels of sVE-cadherin might be a novel biomarker for evaluating the severity of HSP and useful for identifying the presence of SV in inflammatory skin conditions. PMID:24469639

  14. TGF-β signaling links E-cadherin loss to suppression of nucleotide excision repair.

    PubMed

    Qiang, L; Shah, P; Barcellos-Hoff, M H; He, Y Y

    2016-06-23

    E-cadherin is a cell adhesion molecule best known for its function in suppressing tumor progression and metastasis. Here we show that E-cadherin promotes nucleotide excision repair through positively regulating the expression of xeroderma pigmentosum complementation group C (XPC) and DNA damage-binding protein 1 (DDB1). Loss of E-cadherin activates the E2F4 and p130/107 transcription repressor complexes to suppress the transcription of both XPC and DDB1 through activating the transforming growth factor-β (TGF-β) pathway. Adding XPC or DDB1, or inhibiting the TGF-β pathway, increases the repair of ultraviolet (UV)-induced DNA damage in E-cadherin-inhibited cells. In the mouse skin and skin tumors, UVB radiation downregulates E-cadherin. In sun-associated premalignant and malignant skin neoplasia, E-cadherin is downregulated in association with reduced XPC and DDB1 levels. These findings demonstrate a crucial role of E-cadherin in efficient DNA repair of UV-induced DNA damage, identify a new link between epithelial adhesion and DNA repair and suggest a mechanistic link of early E-cadherin loss in tumor initiation. PMID:26477308

  15. Three mechanisms control E-cadherin localization to the zonula adherens

    PubMed Central

    Woichansky, Innokenty; Beretta, Carlo Antonio; Berns, Nicola; Riechmann, Veit

    2016-01-01

    E-cadherin localization to the zonula adherens is fundamental for epithelial differentiation but the mechanisms controlling localization are unclear. Using the Drosophila follicular epithelium we genetically dissect E-cadherin transport in an in vivo model. We distinguish three mechanisms mediating E-cadherin accumulation at the zonula adherens. Two membrane trafficking pathways deliver newly synthesized E-cadherin to the plasma membrane. One is Rab11 dependent and targets E-cadherin directly to the zonula adherens, while the other transports E-cadherin to the lateral membrane. Lateral E-cadherin reaches the zonula adherens by endocytosis and targeted recycling. We show that this pathway is dependent on RabX1, which provides a functional link between early and recycling endosomes. Moreover, we show that lateral E-cadherin is transported to the zonula adherens by an apically directed flow within the plasma membrane. Differential activation of these pathways could facilitate cell shape changes during morphogenesis, while their misregulation compromises cell adhesion and tissue architecture in differentiated epithelia. PMID:26960923

  16. Interfering with VE-PTP stabilizes endothelial junctions in vivo via Tie-2 in the absence of VE-cadherin

    PubMed Central

    Frye, Maike; Dierkes, Martina; Küppers, Verena; Vockel, Matthias; Tomm, Janina; Zeuschner, Dagmar; Rossaint, Jan; Zarbock, Alexander; Koh, Gou Young; Peters, Kevin; Nottebaum, Astrid Fee

    2015-01-01

    Vascular endothelial (VE)–protein tyrosine phosphatase (PTP) associates with VE-cadherin, thereby supporting its adhesive activity and endothelial junction integrity. VE-PTP also associates with Tie-2, dampening the tyrosine kinase activity of this receptor that can support stabilization of endothelial junctions. Here, we have analyzed how interference with VE-PTP affects the stability of endothelial junctions in vivo. Blocking VE-PTP by antibodies, a specific pharmacological inhibitor (AKB-9778), and gene ablation counteracted vascular leak induction by inflammatory mediators. In addition, leukocyte transmigration through the endothelial barrier was attenuated. Interference with Tie-2 expression in vivo reversed junction-stabilizing effects of AKB-9778 into junction-destabilizing effects. Furthermore, lack of Tie-2 was sufficient to weaken the vessel barrier. Mechanistically, inhibition of VE-PTP stabilized endothelial junctions via Tie-2, which triggered activation of Rap1, which then caused the dissolution of radial stress fibers via Rac1 and suppression of nonmuscle myosin II. Remarkably, VE-cadherin gene ablation did not abolish the junction-stabilizing effect of the VE-PTP inhibitor. Collectively, we conclude that inhibition of VE-PTP stabilizes challenged endothelial junctions in vivo via Tie-2 by a VE-cadherin–independent mechanism. In the absence of Tie-2, however, VE-PTP inhibition destabilizes endothelial barrier integrity in agreement with the VE-cadherin–supportive effect of VE-PTP. PMID:26642851

  17. A cadherin-like protein influences Bacillus thuringiensis Cry1Ab toxicity in the oriental armyworm, Mythimna separata.

    PubMed

    Wang, Ling; Jiang, Xingfu; Luo, Lizhi; Stanley, David; Sappington, Thomas W; Zhang, Lei

    2013-06-01

    Cadherins comprise a family of calcium-dependent cell adhesion proteins that act in cell-cell interactions. Cadherin-like proteins (CADs) in midguts of some insects act as receptors that bind some of the toxins produced by the Bacillus thuringiensis (Bt). We cloned a CAD gene associated with larval midguts prepared from Mythimna separata. The full-length cDNA (MsCAD1, GenBank Accession No. JF951432) is 5642 bp, with an open reading frame encoding a 1757 amino acid and characteristics typical of insect CADs. Expression of MsCAD1 is predominantly in midgut tissue, with highest expression in the 3rd- to 6th-instars and lowest in newly hatched larvae. Knocking-down MsCAD1 decreased Cry1Ab susceptibility, indicated by reduced developmental time, increased larval weight and reduced larval mortality. We expressed MsCAD1 in E. coli and recovered the recombinant protein, rMsCAD1, which binds Cry1Ab toxin. Truncation analysis and binding experiments revealed that a contiguous 209-aa, located in CR11 and CR12, is the minimal Cry1Ab binding region. These results demonstrate that MsCAD1 is associated with Cry1Ab toxicity and is one of the Cry1Ab receptors in this insect. The significance of this work lies in identifying MsCAD1 as a Cry1Ab receptor, which helps understand the mechanism of Cry1Ab toxicity and of potential resistance to Bt in M. separata. PMID:23754724

  18. Decreased expression of VE-cadherin and claudin-5 and increased phosphorylation of VE-cadherin in vascular endothelium in nasal polyps.

    PubMed

    Yukitatsu, Yoriko; Hata, Masaki; Yamanegi, Koji; Yamada, Naoko; Ohyama, Hideki; Nakasho, Keiji; Kojima, Yusuke; Oka, Hideki; Tsuzuki, Kenzo; Sakagami, Masafumi; Terada, Nobuyuki

    2013-06-01

    VE-cadherin and claudin-5 are major components of adherens and tight junctions of vascular endothelial cells and a decrease in their expression and an increase in the tyrosine-phosphorylation of VE-cadherin are associated with an increase in endothelial paracellular permeability. To clarify the mechanism underlying the development of edema in nasal polyps, we studied these molecules in polyp microvessels. Normal inferior turbinate mucosal tissues and nasal polyps from patients treated with or without glucocorticoid were stained for VE-cadherin or claudin-5 and CD31 by a double-immunofluorescence method and the immunofluorescence intensities were graded 1-3 with increasing intensity. To correct for differences in fluorescence intensity attributable to a different endothelial area being exposed in a section or to the thickness of a section, the relative immunofluorescence intensity was estimated by dividing the grade of VE-cadherin or claudin-5 by that of CD31 in each microvessel. Tyrosine-phosphorylation of VE-cadherin was examined by Western blot analysis. The relative intensities of VE-cadherin and claudin-5 in the CD31-positive microvessels significantly decreased in the following order; inferior turbinate mucosa, treated polyps and untreated polyps. The ratio of tyrosine-phosphorylated VE-cadherin to VE-cadherin was significantly higher in untreated polyps than in the inferior turbinate mucosa and treated polyps, between which no significant difference in the ratio was seen. Thus, in nasal polyps, the barrier function of endothelial adherens and tight junctions is weakened, although glucocorticoid treatment improves this weakened barrier function. PMID:23474739

  19. Advanced technologies for genetically manipulating the silkworm Bombyx mori, a model Lepidopteran insect

    PubMed Central

    Xu, Hanfu; O'Brochta, David A.

    2015-01-01

    Genetic technologies based on transposon-mediated transgenesis along with several recently developed genome-editing technologies have become the preferred methods of choice for genetically manipulating many organisms. The silkworm, Bombyx mori, is a Lepidopteran insect of great economic importance because of its use in silk production and because it is a valuable model insect that has greatly enhanced our understanding of the biology of insects, including many agricultural pests. In the past 10 years, great advances have been achieved in the development of genetic technologies in B. mori, including transposon-based technologies that rely on piggyBac-mediated transgenesis and genome-editing technologies that rely on protein- or RNA-guided modification of chromosomes. The successful development and application of these technologies has not only facilitated a better understanding of B. mori and its use as a silk production system, but also provided valuable experiences that have contributed to the development of similar technologies in non-model insects. This review summarizes the technologies currently available for use in B. mori, their application to the study of gene function and their use in genetically modifying B. mori for biotechnology applications. The challenges, solutions and future prospects associated with the development and application of genetic technologies in B. mori are also discussed. PMID:26108630

  20. Molecular Design Principles Underlying beta-strand Swapping in the Adhesive Dimerization of Cadherins

    SciTech Connect

    J Vendome; S Posy; X Jin; F Bahna; G Ahlsen; L Shapiro; B Honig

    2011-12-31

    Cell adhesion by classical cadherins is mediated by dimerization of their EC1 domains through the 'swapping' of N-terminal {beta}-strands. We use molecular simulations, measurements of binding affinities and X-ray crystallography to provide a detailed picture of the structural and energetic factors that control the adhesive dimerization of cadherins. We show that strand swapping in EC1 is driven by conformational strain in cadherin monomers that arises from the anchoring of their short N-terminal strand at one end by the conserved Trp2 and at the other by ligation to Ca{sup 2+} ions. We also demonstrate that a conserved proline-proline motif functions to avoid the formation of an overly tight interface where affinity differences between different cadherins, crucial at the cellular level, are lost. We use these findings to design site-directed mutations that transform a monomeric EC2-EC3 domain cadherin construct into a strand-swapped dimer.

  1. E-cadherin expression in colorectal cancer. An immunocytochemical and in situ hybridization study.

    PubMed Central

    Dorudi, S.; Sheffield, J. P.; Poulsom, R.; Northover, J. M.; Hart, I. R.

    1993-01-01

    Expression of the epithelial-specific adhesion molecule E-cadherin has been assessed in paraffin-embedded tissue from a series of 72 colorectal carcinomas. Using immunocytochemistry and in situ hybridization it was found that E-cadherin expression was related inversely to tumor differentiation. Out of 44 well- and moderately differentiated tumors, 36 expressed good positivity, whereas 24 of 28 poorly differentiated tumors were E-cadherin-negative. Classification by Dukes stage revealed a highly significant difference (P << 0.001) between A and B (32 positive, four negative) and C1 and C2 (seven positive, 29 negative) stages in terms of immunoreactivity. Of the 32 lymph node metastases studied, 20 were negative for E-cadherin expression, as were seven of eight liver metastases. These results indicate that the down-regulation of E-cadherin levels in vivo is associated with the dedifferentiation, progression, and metastasis of colorectal cancer. Images Figure 1 Figure 2 PMID:7682766

  2. Pre-metazoan origins and evolution of the cadherin adhesome

    PubMed Central

    Murray, Paul S.; Zaidel-Bar, Ronen

    2014-01-01

    ABSTRACT Vertebrate adherens junctions mediate cell–cell adhesion via a “classical” cadherin–catenin “core” complex, which is associated with and regulated by a functional network of proteins, collectively named the cadherin adhesome (“cadhesome”). The most basal metazoans have been shown to conserve the cadherin–catenin “core”, but little is known about the evolution of the cadhesome. Using a bioinformatics approach based on both sequence and structural analysis, we have traced the evolution of this larger network in 26 organisms, from the uni-cellular ancestors of metazoans, through basal metazoans, to vertebrates. Surprisingly, we show that approximately 70% of the cadhesome, including proteins with similarity to the catenins, predate metazoans. We found that the transition to multicellularity was accompanied by the appearance of a small number of adaptor proteins, and we show how these proteins may have helped to integrate pre-metazoan sub-networks via PDZ domain–peptide interactions. Finally, we found the increase in network complexity in higher metazoans to have been driven primarily by expansion of paralogs. In summary, our analysis helps to explain how the complex protein network associated with cadherin at adherens junctions first came together in the first metazoan and how it evolved into the even more complex mammalian cadhesome. PMID:25395670

  3. N-cadherin deficiency impairs pericyte recruitment, and not endothelial differentiation or sprouting, in embryonic stem cell-derived angiogenesis

    SciTech Connect

    Tillet, Emmanuelle . E-mail: emmanuelle.tillet@cea.fr; Vittet, Daniel; Feraud, Olivier; Moore, Robert; Kemler, Rolf; Huber, Philippe

    2005-11-01

    Endothelial cells express two classical cadherins, VE-cadherin and N-cadherin. VE-cadherin is absolutely required for vascular morphogenesis, but N-cadherin is thought to participate in vessel stabilization by interacting with periendothelial cells during vessel formation. However, recent data suggest a more critical role for N-cadherin in endothelium that would regulate angiogenesis, in part by controlling VE-cadherin expression. In this study, we have assessed N-cadherin function in vascular development using an in vitro model derived from embryonic stem (ES) cell differentiation. We show that pluripotent ES cells genetically null for N-cadherin can differentiate normally into endothelial cells. In addition, sprouting angiogenesis was unaltered, suggesting that N-cadherin is not essential for the early events of angiogenesis. However, the lack of N-cadherin led to an impairment in pericyte covering of endothelial outgrowths. We conclude that N-cadherin is necessary neither for vasculogenesis nor proliferation and migration of endothelial cells but is required for the subsequent maturation of endothelial sprouts by interacting with pericytes.

  4. Soluble Vascular Endothelial Cadherin as a New Biomarker of Irradiation in Highly Irradiated Baboons with Bone Marrow Protection.

    PubMed

    Hérodin, Francis; Voir, Diane; Vilgrain, Isabelle; Courçon, Marie; Drouet, Michel; Boittin, François-Xavier

    2016-06-01

    Vascular endothelial cadherin is the main component of adherens junctions enabling cohesion of the endothelial monolayer in vessels. The extracellular part of vascular endothelial cadherin (VE-cadherin) can be cleaved, releasing soluble fragments in blood (sVE-cadherin). In some diseases with endothelial dysfunction, a correlation between increased blood sVE-cadherin levels and disease state has been proposed. Irradiation is known to induce endothelial damage, but new serum biomarkers are needed to evaluate endothelial damage after irradiation. Here, the authors investigated whether sVE-cadherin may be an interesting biomarker of irradiation in highly irradiated baboons with bone marrow protection. sVE-cadherin was detected in the plasma of young as well as old baboons. Plasma sVE-cadherin levels significantly decrease a few days after irradiation but recover in the late time after irradiation. Kinetic analysis of plasma sVE-cadherin levels suggests a correlation with white blood cell counts in both the acute phase of irradiation and during hematopoietic recovery, suggesting that plasma sVE-cadherin levels may be partly linked to the disappearance and recovery of white blood cells. Interestingly, after hematopoietic recovery was completed, sVE-cadherin levels were found to exceed control values, suggesting that plasma sVE-cadherin may represent a new biomarker of endothelial damage or neovascularization in the late time after irradiation. PMID:27115227

  5. Antioxidants Maintain E-Cadherin Levels to Limit Drosophila Prohemocyte Differentiation

    PubMed Central

    Gao, Hongjuan; Wu, Xiaorong; Simon, LaTonya; Fossett, Nancy

    2014-01-01

    Mitochondrial reactive oxygen species (ROS) regulate a variety of biological processes by networking with signal transduction pathways to maintain homeostasis and support adaptation to stress. In this capacity, ROS have been shown to promote the differentiation of progenitor cells, including mammalian embryonic and hematopoietic stem cells and Drosophila hematopoietic progenitors (prohemocytes). However, many questions remain about how ROS alter the regulatory machinery to promote progenitor differentiation. Here, we provide evidence for the hypothesis that ROS reduce E-cadherin levels to promote Drosophila prohemocyte differentiation. Specifically, we show that knockdown of the antioxidants, Superoxide dismutatase 2 and Catalase reduce E-cadherin protein levels prior to the loss of Odd-skipped-expressing prohemocytes. Additionally, over-expression of E-cadherin limits prohemocyte differentiation resulting from paraquat-induced oxidative stress. Furthermore, two established targets of ROS, Enhancer of Polycomb and FOS, control the level of E-cadherin protein expression. Finally, we show that knockdown of either Superoxide dismutatase 2 or Catalase leads to an increase in the E-cadherin repressor, Serpent. As a result, antioxidants and targets of ROS can control E-cadherin protein levels, and over-expression of E-cadherin can ameliorate the prohemocyte response to oxidative stress. Collectively, these data strongly suggest that ROS promote differentiation by reducing E-cadherin levels. In mammalian systems, ROS promote embryonic stem cell differentiation, whereas E-cadherin blocks differentiation. However, it is not known if elevated ROS reduce E-cadherin to promote embryonic stem cell differentiation. Thus, our findings may have identified an important mechanism by which ROS promote stem/progenitor cell differentiation. PMID:25226030

  6. N-cadherin haploinsufficiency affects cardiac gap junctions and arrhythmic susceptibility

    PubMed Central

    Li, Jifen; Levin, Mark D; Xiong, Yanming; Petrenko, Nataliya; Patel, Vickas V.; Radice, Glenn L.

    2008-01-01

    Cardiac-specific deletion of the murine gene (Cdh2) encoding the cell adhesion molecule, N-cadherin, results in disassembly of the intercalated disc (ICD) structure and sudden arrhythmic death. Connexin 43 (Cx43)-containing gap junctions are significantly reduced in the heart after depleting N-cadherin, therefore we hypothesized that animals expressing half the normal levels of N-cadherin would exhibit an intermediate phenotype. We examined the effect of N-cadherin haploinsufficiency on Cx43 expression and susceptibility to induced arrhythmias in mice either wild-type or heterozygous for the Cx43 (Gja1)-null allele. An increase in hypophosphorylated Cx43 accompanied by a modest decrease in total Cx43 protein levels was observed in the N-cadherin heterozygous mice. Consistent with these findings N-cadherin heterozygotes exhibited increased susceptibility to ventricular arrhythmias compared to wild-type mice. Quantitative immunofluorescence microscopy revealed a reduction in size of large Cx43-containing plaques in the N-cadherin heterozygous animals compared to wild-type. Gap junctions were further decreased in number and size in the N-cad/Cx43 compound heterozygous mice with increased arrhythmic susceptibility compared to the single mutants. The scaffold protein, ZO-1, was reduced at the ICD in N-cadherin heterozygous cardiomyocytes providing a possible explanation for the reduction in Cx43 plaque size. These data provide further support for the intimate relationship between N-cadherin and Cx43 in the heart, and suggest that germline mutations in the human N-cadherin (Cdh2) gene may predispose patients to increased risk of cardiac arrhythmias. PMID:18201716

  7. A Novel Role of E-Cadherin-Based Adherens Junctions in Neoplastic Cell Dissemination

    PubMed Central

    Gloushankova, Natalya A.

    2015-01-01

    Using confocal microscopy, we analyzed the behavior of IAR-6-1, IAR1170, and IAR1162 transformed epithelial cells seeded onto the confluent monolayer of normal IAR-2 epithelial cells. Live-cell imaging of neoplastic cells stably expressing EGFP and of normal epithelial cells stably expressing mKate2 showed that transformed cells retaining expression of E-cadherin were able to migrate over the IAR-2 epithelial monolayer and invade the monolayer. Transformed IAR cells invaded the IAR-2 monolayer at the boundaries between normal cells. Studying interactions of IAR-6-1 transformed cells stably expressing GFP-E-cadherin with the IAR-2 epithelial monolayer, we found that IAR-6-1 cells established E-cadherin-based adhesions with normal epithelial cells: dot-like dynamic E-cadherin-based adhesions in protrusions and large adherens junctions at the cell sides and rear. A comparative study of a panel of transformed IAR cells that differ by their ability to form E-cadherin-based AJs, either through loss of E-cadherin expression or through expression of a dominant negative E-cadherin mutant, demonstrated that E-cadherin-based AJs are key mediators of the interactions between neoplastic and normal epithelial cells. IAR-6-1DNE cells expressing a dominant-negative mutant form of E-cadherin with the mutation in the first extracellular domain practically lost the ability to adhere to IAR-2 cells and invade the IAR-2 epithelial monolayer. The ability of cancer cells to form E-cadherin-based AJs with the surrounding normal epithelial cells may play an important role in driving cancer cell dissemination in the body. PMID:26207916

  8. Epigenetic regulation of E-cadherin expression by the histone demethylase UTX in colon cancer cells.

    PubMed

    Zha, Lin; Cao, Qiang; Cui, Xin; Li, Fenfen; Liang, Houjie; Xue, Bingzhong; Shi, Hang

    2016-03-01

    Decreased epithelial cadherin (E-cadherin) gene expression, a hallmark of epithelial-mesenchymal transition (EMT), is essential for triggering metastatic advantage of the colon cancer. Genetic mechanisms underlying the regulation of E-cadherin expression in EMT have been extensively investigated; however, much is unknown about the epigenetic mechanism underlying this process. Here, we identified ubiquitously transcribed tetratricopeptide repeat on chromosome X (UTX), a histone demethylase involved in demethylating di- or tri-methylated histone 3 lysine 27 (H3K27me2/3), as a positive regulator for the expression of E-cadherin in the colon cancer cell line HCT-116. We showed that inactivation of UTX down-regulated E-cadherin gene expression, while overexpression of UTX did the opposite. Notably, overexpression of UTX inhibited migration and invasion of HCT-116 cells. Moreover, UTX demethylated H3K27me3, a histone transcriptional repressive mark, leading to decreased H3K27me3 at the E-cadherin promoter. Further, UTX interacted with the histone acetyltransferase (HAT) protein CBP and recruited it to the E-cadherin promoter, resulting in increased H3K27 acetylation (H3K27ac), a histone transcriptional active mark. UTX positively regulates E-cadherin expression through coordinated regulation of H3K27 demethylation and acetylation, switching the transcriptional repressive state to the transcriptional active state at the E-cadherin promoter. We conclude that UTX may play a role in regulation of E-cadherin gene expression in HCT-116 cells and that UTX may serve as a therapeutic target against the metastasis in the treatment of colon cancer. PMID:26819089

  9. Mechanistic Projection of First-in-Human Dose for Bispecific Immunomodulatory P-Cadherin LP-DART: An Integrated PK/PD Modeling Approach.

    PubMed

    Chen, X; Haddish-Berhane, N; Moore, P; Clark, T; Yang, Y; Li, H; Xuan, D; Barton, H A; Betts, A M; Barletta, F

    2016-09-01

    A bispecific immunomodulatory biotherapeutic molecule (P-cadherin LP-DART) based on the Dual Affinity Re-Targeting (DART) scaffold has been developed as a potential antitumor treatment showing efficacy in preclinical testing. A minimal anticipated biological effect level (MABEL) approach was applied to project the first-in-human (FIH) dose, because of its immune agonistic properties following target engagement. The pharmacological activity of P-cadherin LP-DART is driven by binding to both P-cadherin on the tumor cells and CD3 on T cells. Therefore, the concentration of the tri-molecular synapse formed between drug, T cell, and tumor cell, rather than drug concentration, is responsible for efficacy. A mechanistic pharmacokinetic/pharmacodynamic (PK/PD)-driven approach was explored to understand the exposure-response relationship based on the synapse concentration to project the MABEL dose. Orthogonal approaches including PK-driven and receptor occupancy calculations were also investigated. This study showcases the application of PK/PD modeling in immune-oncology, and could potentially be implemented for other bispecific biotherapeutics. PMID:27170541

  10. Correlation of E-cadherin expression with differentiation grade and histological type in breast carcinoma.

    PubMed Central

    Gamallo, C.; Palacios, J.; Suarez, A.; Pizarro, A.; Navarro, P.; Quintanilla, M.; Cano, A.

    1993-01-01

    Recently, a correlation has been suggested between a loss of E-cadherin (E-CD) and increased invasiveness of neoplastic cells. In this study, E-CD expression in breast cancer was investigated using an affinity-purified antibody (ECCD-2) in an immunoenzymatic (avidin-biotin-alkaline phosphatase) test. Intensity and extension of E-CD immunoreactivity were evaluated in 61 breast carcinomas and correlated with their histological type and grade, nodal involvement, and hormonal receptor status. Histological types were infiltrating ductal carcinoma of no special type (n = 54) and infiltrating lobular carcinoma (n = 7). All infiltrating ductal carcinomas of no special type except two grade 3 carcinomas showed positive immunoreactivity that was variable among different cases. Grade 1 breast carcinomas (n = 10) showed greater immunoreactivity than grade 2 (n = 25) and grade 3 (n = 19) carcinomas. E-CD immunoreactivity correlated positively with the degree of tubular formation and inversely with the mitoses number. None of the infiltrating lobular carcinomas expressed E-CD in their infiltrating cells, whereas they showed only weak immunostains in areas of atypical lobular hyperplasia and lobular carcinoma in situ. These results indicate that E-CD expression correlates with histological type and grade in breast carcinomas. Images Figure 1 Figure 2 Figure 3 PMID:7682767