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Yoshimi Takai - One of the best experts on this subject based on the ideXlab platform.
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interaction of necl 4 cadm4 with erbb3 and integrin α6β4 and inhibition of erbb2 erbb3 signaling and hemidesmosome disassembly
Genes to Cells, 2013Co-Authors: Hirokazu Sugiyama, Kiyohito Mizutani, Naomasa Okimoto, Yohei Shimono, Souichi Kurita, Yoshimi TakaiAbstract:Nectin-like molecule 4 (Necl-4)/CADM4, a transmembrane cell–cell adhesion molecule with three Ig-like domains, was shown to serve as a tumor suppressor, but its mode of action has not been elucidated. In this study, we showed that Necl-4 interacted in cis with ErbB3 through their extracellular regions, recruited PTPN13 and inhibited the heregulin-induced activation of the ErbB2/ErbB3 signaling. In addition, we extended our previous finding that Necl-4 interacts in cis with integrin α6β4 through their extracellular regions and found that Necl-4 inhibited the phorbol ester-induced disassembly of hemidesmosomes. These results indicate that Necl-4 serves as a tumor suppressor by inhibiting the ErbB2/ErbB3 signaling and hemidesmosome disassembly.
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reduction of the st6 β galactosamide α 2 6 sialyltransferase 1 st6gal1 catalyzed sialylation of nectin like molecule 2 cell adhesion molecule 1 and enhancement of erbb2 erbb3 signaling by microrna 199a
Journal of Biological Chemistry, 2013Co-Authors: Akihiro Minami, Kiyohito Mizutani, Yohei Shimono, Kentaro Nobutani, Kenji Momose, Takeshi Azuma, Yoshimi TakaiAbstract:Nectin-like molecule 2 (Necl-2)/cell adhesion molecule 1 (CADM1) is shown to be down-regulated by the promoter hypermethylation and/or loss of heterozygosity at chromosome 11q23.2 in many types of cancers, including lung and breast cancers, and is proposed to serve as a tumor suppressor. However, the incidence of these epigenetic and genetic abnormalities of Necl-2 is 30–60% in these cancers, and other mechanisms for the suppression of Necl-2 are presumed to be present. We previously showed that Necl-2 interacts in cis with ErbB3 and suppresses the heregulin (HRG)-induced ErbB2/ErbB3 signaling for cell movement and death. We studied here the relationship between Necl-2 and microRNA-199a (miR-199a) that is up-regulated or down-regulated in a variety of cancers. miR-199a did not directly target the Necl-2 mRNA or affect its mRNA level in human lung cancer A549 cells and human embryonic kidney HEK293 cells. Necl-2 was at least sialylated by the sialyltransferase ST6 β-galactosamide α-2,6-sialyltransferase 1 (ST6GAL1). miR-199a targeted ST6GAL1 and reduced both the sialylation and the protein level of Necl-2. In addition, miR-199a enhanced the HRG-induced ErbB2/ErbB3 signaling. These results indicate that the suppressive role of Necl-2 in the HRG-induced ErbB2/ErbB3 signaling is regulated by miR-199a at least through the reduction of the ST6GAL1-catalyzed sialylation of Necl-2 and/or through the reduction of the protein level of Necl-2 presumably by the protein degradation.
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involvement of up regulated necl 5 tage4 pvr cd155 in the loss of contact inhibition in transformed nih3t3 cells
Biochemical and Biophysical Research Communications, 2007Co-Authors: Yukiko Minami, Wataru Ikeda, Morito Monden, Tsutomu Fujito, Mihoko Kajita, Yoshimi TakaiAbstract:Normal cells show contact inhibition of cell movement and proliferation, but this is lost following transformation. We found that Necl-5, originally identified as a poliovirus receptor and up-regulated in many cancer cells, enhances growth factor-induced cell movement and proliferation. We showed that when cells contact other cells, Necl-5 interacts in trans with nectin-3 and is removed by endocytosis from the cell surface, resulting in a reduction of cell movement and proliferation. We show here that up-regulation of the gene encoding Necl-5 by the oncogene V12-Ki-Ras causes enhanced cell movement and proliferation. Upon cell-cell contact, de novo synthesis of Necl-5 exceeds the rate of Necl-5 endocytosis, eventually resulting in a net increase in the amount of Necl-5 at the cell surface. In addition, expression of the gene encoding nectin-3 is markedly reduced in transformed cells. Thus, up-regulation of Necl-5 following transformation contributes to the loss of contact inhibition in transformed cells.
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inhibition of cell movement and proliferation by cell cell contact induced interaction of necl 5 with nectin 3
Journal of Cell Biology, 2005Co-Authors: Tsutomu Fujito, Shigeki Kakunaga, Wataru Ikeda, Morito Monden, Yukiko Minami, Mihoko Kajita, Yasuhisa Sakamoto, Yoshimi TakaiAbstract:Immunoglobulin-like Necl-5/Tage4/poliovirus receptor (PVR)/CD155, originally identified as the PVR, has been shown to be up-regulated in cancer cells and to enhance growth factor–induced cell movement and proliferation. In addition, Necl-5 heterophilically trans-interacts with nectin-3, a cell–cell adhesion molecule known to form adherens junctions in cooperation with cadherin. We show here that Necl-5 was down-regulated from cell surface upon cell–cell contacts in NIH3T3 cells. This down-regulation of Necl-5 was initiated by its interaction with nectin-3 and was mainly mediated by clathrin-dependent endocytosis. Then, the down-regulation of Necl-5 induced in this way reduced movement and proliferation of NIH3T3 cells. These results indicate that the down-regulation of Necl-5 induced by its interaction with nectin-3 upon cell–cell contacts may be at least one mechanism underlying contact inhibition of cell movement and proliferation.
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transcriptional activation of the mouse necl 5 tage4 pvr cd155 gene by fibroblast growth factor or oncogenic ras through the raf mek erk ap 1 pathway
Oncogene, 2005Co-Authors: Takeshi Hirota, Kenji Irie, Wataru Ikeda, Ryoko Okamoto, Yoshimi TakaiAbstract:Necl-5/Tage4/poliovirus receptor/CD155 is the poliovirus receptor and upregulated in rodent and human carcinoma. We have recently shown that mouse Necl-5 is upregulated by an oncogenic Ki-Ras (V12Ki-Ras) in NIH3T3 cells and enhances cell movement induced by growth factors, including platelet-derived growth factor and fibroblast growth factor (FGF), in an integrin αvβ3-dependent manner in wild type and V12Ki-Ras-transformed NIH3T3 cells. In addition, it enhances the growth factor-induced cell proliferation. We examined here how mouse Necl-5 was upregulated by V12Ki-Ras in NIH3T3 cells. Expression of the luciferase reporter gene fused to the Necl-5 promoter was induced by V12Ki-Ras in NIH3T3 cells. This induction was mediated through the Raf–MEK–ERK pathway. The Necl-5 promoter has an AP-1-binding site and this site was required for the V12Ki-Ras-induced activation of the Necl-5 promoter. Expression of the luciferase reporter gene fused to the Necl-5 promoter was also induced by FGF through the Raf–MEK–ERK–AP-1 pathway in NIH3T3 cells. These results indicate that the expression of mouse Necl-5 is induced by FGF or V12Ki-Ras through the Raf–MEK–ERK–AP-1 pathway.
Wataru Ikeda - One of the best experts on this subject based on the ideXlab platform.
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involvement of up regulated necl 5 tage4 pvr cd155 in the loss of contact inhibition in transformed nih3t3 cells
Biochemical and Biophysical Research Communications, 2007Co-Authors: Yukiko Minami, Wataru Ikeda, Morito Monden, Tsutomu Fujito, Mihoko Kajita, Yoshimi TakaiAbstract:Normal cells show contact inhibition of cell movement and proliferation, but this is lost following transformation. We found that Necl-5, originally identified as a poliovirus receptor and up-regulated in many cancer cells, enhances growth factor-induced cell movement and proliferation. We showed that when cells contact other cells, Necl-5 interacts in trans with nectin-3 and is removed by endocytosis from the cell surface, resulting in a reduction of cell movement and proliferation. We show here that up-regulation of the gene encoding Necl-5 by the oncogene V12-Ki-Ras causes enhanced cell movement and proliferation. Upon cell-cell contact, de novo synthesis of Necl-5 exceeds the rate of Necl-5 endocytosis, eventually resulting in a net increase in the amount of Necl-5 at the cell surface. In addition, expression of the gene encoding nectin-3 is markedly reduced in transformed cells. Thus, up-regulation of Necl-5 following transformation contributes to the loss of contact inhibition in transformed cells.
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inhibition of cell movement and proliferation by cell cell contact induced interaction of necl 5 with nectin 3
Journal of Cell Biology, 2005Co-Authors: Tsutomu Fujito, Shigeki Kakunaga, Wataru Ikeda, Morito Monden, Yukiko Minami, Mihoko Kajita, Yasuhisa Sakamoto, Yoshimi TakaiAbstract:Immunoglobulin-like Necl-5/Tage4/poliovirus receptor (PVR)/CD155, originally identified as the PVR, has been shown to be up-regulated in cancer cells and to enhance growth factor–induced cell movement and proliferation. In addition, Necl-5 heterophilically trans-interacts with nectin-3, a cell–cell adhesion molecule known to form adherens junctions in cooperation with cadherin. We show here that Necl-5 was down-regulated from cell surface upon cell–cell contacts in NIH3T3 cells. This down-regulation of Necl-5 was initiated by its interaction with nectin-3 and was mainly mediated by clathrin-dependent endocytosis. Then, the down-regulation of Necl-5 induced in this way reduced movement and proliferation of NIH3T3 cells. These results indicate that the down-regulation of Necl-5 induced by its interaction with nectin-3 upon cell–cell contacts may be at least one mechanism underlying contact inhibition of cell movement and proliferation.
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transcriptional activation of the mouse necl 5 tage4 pvr cd155 gene by fibroblast growth factor or oncogenic ras through the raf mek erk ap 1 pathway
Oncogene, 2005Co-Authors: Takeshi Hirota, Kenji Irie, Wataru Ikeda, Ryoko Okamoto, Yoshimi TakaiAbstract:Necl-5/Tage4/poliovirus receptor/CD155 is the poliovirus receptor and upregulated in rodent and human carcinoma. We have recently shown that mouse Necl-5 is upregulated by an oncogenic Ki-Ras (V12Ki-Ras) in NIH3T3 cells and enhances cell movement induced by growth factors, including platelet-derived growth factor and fibroblast growth factor (FGF), in an integrin αvβ3-dependent manner in wild type and V12Ki-Ras-transformed NIH3T3 cells. In addition, it enhances the growth factor-induced cell proliferation. We examined here how mouse Necl-5 was upregulated by V12Ki-Ras in NIH3T3 cells. Expression of the luciferase reporter gene fused to the Necl-5 promoter was induced by V12Ki-Ras in NIH3T3 cells. This induction was mediated through the Raf–MEK–ERK pathway. The Necl-5 promoter has an AP-1-binding site and this site was required for the V12Ki-Ras-induced activation of the Necl-5 promoter. Expression of the luciferase reporter gene fused to the Necl-5 promoter was also induced by FGF through the Raf–MEK–ERK–AP-1 pathway in NIH3T3 cells. These results indicate that the expression of mouse Necl-5 is induced by FGF or V12Ki-Ras through the Raf–MEK–ERK–AP-1 pathway.
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nectin like molecule 1 tsll1 syncam3 a neural tissue specific immunoglobulin like cell cell adhesion molecule localizing at non junctional contact sites of presynaptic nerve terminals axons and glia cell processes
Journal of Cell Science, 2005Co-Authors: Shigeki Kakunaga, Akira Mizoguchi, Wataru Ikeda, Shinsuke Itoh, Toshihisa Ohtsuka, Maki Deguchitawarada, Yoshimi TakaiAbstract:Nectins are Ca2+-independent immunoglobulin-like cell-cell adhesion molecules and comprise a family of four members. At the mossy fiber terminals of hippocampus, nectin-1 and nectin-3 localize at the presynaptic and postsynaptic sides of synaptic junctions, respectively, and their trans-interactions play a role in formation of synapses in cooperation with N-cadherin. Nectins are associated with the actin cytoskeleton through afadin, a nectin- and actin-filament-binding protein. Five nectin-like molecules (Necls) which have domain structures similar to those of nectins have been identified and here we characterize Necl-1/TSLL1/SynCAM3, from now on referred to as Necl-1. Tissue distribution analysis showed that Necl-1 was specifically expressed in the neural tissue. Immunofluorescence and immunoelectron microscopy revealed that Necl-1 localized at the contact sites among axons, their terminals, and glia cell processes that cooperatively formed synapses, axon bundles and myelinated axons. Necl-1 showed Ca2+-independent homophilic cell-cell adhesion activity. It furthermore showed Ca2+-independent heterophilic cell-cell adhesion activity with Necl-2/IGSF4/RA175/SgIGSF/TSLC1/SynCAM1 from now on referred to as Necl-2, nectin-1 and nectin-3, but not with Necl-5 or nectin-2. The C-terminal cytoplasmic region of Necl-1 did not bind afadin but bound membrane-associated guanylate kinase subfamily members that contain the L27 domain, including Dlg3, Pals2 and CASK. These results indicate that Necl-1 is a neural-tissue-specific Ca2+-independent immunoglobulin-like cell-cell adhesion molecule which potentially has membrane-associated guanylate kinase subfamily member-binding activity and localizes at the non-junctional cell-cell contact sites.
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involvement of heterophilic trans interaction of necl 5 tage4 pvr cd155 with nectin 3 in formation of nectin and cadherin based adherens junctions
Genes to Cells, 2004Co-Authors: Tatsuhiro Sato, Wataru Ikeda, Kenji Irie, Takako Ooshio, Yoshimi TakaiAbstract:Nectins, Ca2+-independent immunoglobulin (Ig)-like cell–cell adhesion molecules and cadherins, Ca2+-dependent cell–cell adhesion molecules, are associated through their respective cytoplasmic tail-binding proteins, afadin and catenins and play roles in formation of adherens junctions (AJs) in epithelial cells and fibroblasts. Nectin-like molecule-5 (Necl-5) is a Ca2+-independent Ig-like molecule which does not homophilically trans-interact, but heterophilically trans-interacts with nectin-3, one member of the nectin family. Necl-5 does not directly bind afadin and therefore is not associated with cadherins. Necl-5 regulates cell motility and proliferation in cooperation with integrins and growth factor receptors, when it does not interact with nectin-3. We studied here a role of the heterophilic trans-interaction of Necl-5 with nectin-3 in cell–cell adhesion using L cells stably expressing Necl-5, nectin-3 and E-cadherin (Necl-5-nectin-3-EL cells). Afadin, E-cadherin and catenins were recruited to the nectin-3 side, but not to the Necl-5 side, of the contact sites formed by the heterophilic trans-interaction between Necl-5 and nectin-3. The anti-Necl-5 monoclonal antibody, which specifically inhibited the heterophilic trans-interaction of Necl-5 with nectin-3, inhibited the formation of the E-cadherin-based AJs in Necl-5-nectin-3-EL cells. These results indicate that Necl-5 plays roles not only in cell motility and proliferation but also in cell–cell adhesion in cooperation with nectin-3.
Shigeki Kakunaga - One of the best experts on this subject based on the ideXlab platform.
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inhibition of cell movement and proliferation by cell cell contact induced interaction of necl 5 with nectin 3
Journal of Cell Biology, 2005Co-Authors: Tsutomu Fujito, Shigeki Kakunaga, Wataru Ikeda, Morito Monden, Yukiko Minami, Mihoko Kajita, Yasuhisa Sakamoto, Yoshimi TakaiAbstract:Immunoglobulin-like Necl-5/Tage4/poliovirus receptor (PVR)/CD155, originally identified as the PVR, has been shown to be up-regulated in cancer cells and to enhance growth factor–induced cell movement and proliferation. In addition, Necl-5 heterophilically trans-interacts with nectin-3, a cell–cell adhesion molecule known to form adherens junctions in cooperation with cadherin. We show here that Necl-5 was down-regulated from cell surface upon cell–cell contacts in NIH3T3 cells. This down-regulation of Necl-5 was initiated by its interaction with nectin-3 and was mainly mediated by clathrin-dependent endocytosis. Then, the down-regulation of Necl-5 induced in this way reduced movement and proliferation of NIH3T3 cells. These results indicate that the down-regulation of Necl-5 induced by its interaction with nectin-3 upon cell–cell contacts may be at least one mechanism underlying contact inhibition of cell movement and proliferation.
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nectin like molecule 1 tsll1 syncam3 a neural tissue specific immunoglobulin like cell cell adhesion molecule localizing at non junctional contact sites of presynaptic nerve terminals axons and glia cell processes
Journal of Cell Science, 2005Co-Authors: Shigeki Kakunaga, Akira Mizoguchi, Wataru Ikeda, Shinsuke Itoh, Toshihisa Ohtsuka, Maki Deguchitawarada, Yoshimi TakaiAbstract:Nectins are Ca2+-independent immunoglobulin-like cell-cell adhesion molecules and comprise a family of four members. At the mossy fiber terminals of hippocampus, nectin-1 and nectin-3 localize at the presynaptic and postsynaptic sides of synaptic junctions, respectively, and their trans-interactions play a role in formation of synapses in cooperation with N-cadherin. Nectins are associated with the actin cytoskeleton through afadin, a nectin- and actin-filament-binding protein. Five nectin-like molecules (Necls) which have domain structures similar to those of nectins have been identified and here we characterize Necl-1/TSLL1/SynCAM3, from now on referred to as Necl-1. Tissue distribution analysis showed that Necl-1 was specifically expressed in the neural tissue. Immunofluorescence and immunoelectron microscopy revealed that Necl-1 localized at the contact sites among axons, their terminals, and glia cell processes that cooperatively formed synapses, axon bundles and myelinated axons. Necl-1 showed Ca2+-independent homophilic cell-cell adhesion activity. It furthermore showed Ca2+-independent heterophilic cell-cell adhesion activity with Necl-2/IGSF4/RA175/SgIGSF/TSLC1/SynCAM1 from now on referred to as Necl-2, nectin-1 and nectin-3, but not with Necl-5 or nectin-2. The C-terminal cytoplasmic region of Necl-1 did not bind afadin but bound membrane-associated guanylate kinase subfamily members that contain the L27 domain, including Dlg3, Pals2 and CASK. These results indicate that Necl-1 is a neural-tissue-specific Ca2+-independent immunoglobulin-like cell-cell adhesion molecule which potentially has membrane-associated guanylate kinase subfamily member-binding activity and localizes at the non-junctional cell-cell contact sites.
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enhancement of serum and platelet derived growth factor induced cell proliferation by necl 5 tage4 poliovirus receptor cd155 through the ras raf mek erk signaling
Journal of Biological Chemistry, 2004Co-Authors: Shigeki Kakunaga, Wataru Ikeda, Tatsushi Shingai, Toshio Imai, Tsutomu Fujito, Akio Yamada, Yukiko Minami, Yoshimi TakaiAbstract:Necl-5/Tage4/poliovirus receptor/CD155 has been shown to be the poliovirus receptor and to be up-regulated in rodent and human carcinoma. We have found previously that mouse Necl-5 regulates cell motility. We show here that mouse Necl-5 is furthermore involved in the regulation of cell proliferation. Studies using a specific antibody against Necl-5 and a dominant negative mutant of Necl-5 revealed that Necl-5 enhanced the serum-induced proliferation of NIH3T3, Swiss3T3, and mouse embryonic fibroblast cells. Necl-5 enhanced the serum-induced activation of the Ras-Raf-MEK-ERK signaling, up-regulated cyclins D2 and E, and down-regulated p27(Kip1), eventually shortening the period of the G(0)/G(1) phase of the cell cycle in NIH3T3 cells. Necl-5 similarly enhanced the platelet-derived growth factor-induced activation of the Ras-Raf-MEK-ERK signaling and shortened the period of the G(0)/G(1) phase of the cell cycle in NIH3T3 cells. Necl-5 acted downstream of the platelet-derived growth factor receptor and upstream of Ras. Moreover, up-regulated Necl-5 was involved at least partly in the enhanced proliferation of transformed cells including NIH3T3 cells transformed by an oncogenic Ras or v-Src. These results indicate that Necl-5 plays roles not only in cell motility but also in cell proliferation.
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nectin like molecule 5 tage4 enhances cell migration in an integrin dependent nectin 3 independent manner
Journal of Biological Chemistry, 2004Co-Authors: Wataru Ikeda, Shigeki Kakunaga, Koji Morimoto, Kyoji Takekuni, Masakazu Takeuchi, Tatsushi Shingai, Keiko Satoh, Toshio Imai, Yoshimi TakaiAbstract:Abstract Cell migration plays roles in invasion of transformed cells and scattering of embryonic mesenchymal cells into surrounding tissues. We have found that Ig-like Necl-5/Tage4 is up-regulated in NIH3T3 cells transformed by an oncogenic Ras (V12Ras-NIH3T3 cells) and heterophilically trans-interacts with a Ca2+-independent Ig-like cell adhesion molecule nectin-3, eventually enhancing their intercellular motility. We show here that Necl-5 furthermore enhances cell migration in a nectin-3-independent manner. Studies using L fibroblasts expressing various mutants of Necl-5, NIH3T3 cells, and V12Ras-NIH3T3 cells have revealed that Necl-5 enhances serum- and platelet-derived growth factor-induced cell migration. The extracellular region of Necl-5 is necessary for directional cell migration, but not for random cell motility. The cytoplasmic region of Necl-5 is necessary for both directional and random cell movement. Necl-5 colocalizes with integrin αVβ3 at leading edges of migrating cells. Analyses using an inhibitor or an activator of integrin αVβ3 or a dominant negative mutant of Necl-5 have shown the functional association of Necl-5 with integrin αVβ3 in cell motility. Cdc42 and Rac small G proteins are activated by the action of Necl-5 and required for the serum-induced, Necl-5-enhanced cell motility. These results indicate that Necl-5 regulates serum- and platelet-derived growth factor-induced cell migration in an integrin-dependent, nectin-3-independent manner, when cells do not contact other cells. We furthermore show here that enhanced motility and metastasis of V12Ras-NIH3T3 cells are at least partly the result of up-regulated Necl-5.
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implications of nectin like molecule 2 igsf4 ra175 sgigsf tslc1 syncam1 in cell cell adhesion and transmembrane protein localization in epithelial cells
Journal of Biological Chemistry, 2003Co-Authors: Tatsushi Shingai, Shigeki Kakunaga, Wataru Ikeda, Shinsuke Itoh, Koji Morimoto, Kyoji Takekuni, Masakazu Takeuchi, Keiko Satoh, Toshio Imai, Morito MondenAbstract:Nectins are Ca2+-independent immunoglobulin-like cell-cell adhesion molecules that play roles in organization of a variety of cell-cell junctions in cooperation with or independently of cadherins. Four nectins have been identified. Five nectin-like molecules, which have domain structures similar to those of nectins, have been identified, and we characterized here nectin-like molecule-2 (Necl-2)/IGSF4/RA175/SgIGSF/TSLC1/SynCAM1. Necl-2 showed Ca2+-independent homophilic cell-cell adhesion activity. It furthermore showed Ca2+-independent heterophilic cell-cell adhesion activity with Necl-1/TSLL1/SynCAM3 and nectin-3. Necl-2 was widely expressed in rat tissues examined. Necl-2 localized at the basolateral plasma membrane in epithelial cells of the mouse gall bladder, but not at specialized cell-cell junctions, such as tight junctions, adherens junctions, and desmosomes. Nectins bind afadin, whereas Necl-2 did not bind afadin but bound Pals2, a membrane-associated guanylate kinase family member known to bind Lin-7, implicated in the proper localization of the Let-23 protein in Caenorhabditis elegans, the homologue of mammalian epidermal growth factor receptor. These results indicate the unique localization of Necl-2 and its possible involvement in localization of a transmembrane protein(s) through Pals2.
Byung-ok Choi - One of the best experts on this subject based on the ideXlab platform.
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NEFL Pro22Arg mutation in Charcot-Marie-Tooth disease type 1
Journal of Human Genetics, 2008Co-Authors: Ji Soo Shin, Ki Wha Chung, Su Jin Hwang, Sung Hee Kang, Byung-ok ChoiAbstract:Charcot-Marie-Tooth disease (CMT) is classified into demyelinating neuropathy (CMT1) and axonal neuropathy (CMT2). Mutations in the neurofilament light chain polypeptide ( NEFL ) gene are present in CMT2E and CMT1F neuropathies. Two types of Pro22 mutations have been previously reported: Pro22Ser in CMT2E with giant axons, and Pro22Thr in CMT1F. In this study, we identified another Pro22 mutation, Pro22Arg, in a Korean CMT1 family. An investigation to identify the clinical and pathological characteristics of the Pro22Arg revealed that it is associated with demyelinating neuropathy features in CMT1F. Histopathological findings showed onion bulb formations but no giant axons. It appears that the Pro22 mutations may influence not only the Thr-Pro phosphorylation site by proline-directed protein kinases but also other structural alteration of the NEFL protein in a different way.
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mutational analysis of the neurofilament light chain NEFL gene in patients with charcot marie tooth disease
Journal of the Korean neurological association, 2005Co-Authors: Hyunji Cho, Ki Wha Chung, Ilnam Sunwoo, Keeduk Park, Bumchun Seo, Misun Lee, Eunkyoung Youn, Byung-ok ChoiAbstract:Background: Charcot-Marie-Tooth (CMT) disease is the most common form of inherited motor and sensory neuropathy. Neurofilament light chain polypeptide (NEFL) is one of the most abundant cytoskeletal components of the neuron. The NEFL gene encoding the neurofilament light chain plays an important role in the axonal structure that includes an extensive fibrous network in the cytoplasm of the neuron. Mutations in the NEFL gene are also present in CMT2E, CMT type 1 and Dejerine-Sottas syndrome. However, there have been no reports to investigate the NEFL genes in Korean CMT patients. Therefore, we investigated to find the clinical characteristics in patients with the NEFL gene mutation. Methods: We examined mutations of the NEFL gene in 125 Korean CMT families. Mutations were confirmed by the sequencing of both strands. Nerve conduction studies were carried out on CMT patients having each mutation. Results: Three pathogenic mutations were found in 3 families, and 2 polymorphisms in 2 families. Two mutations (Leu334Pro, Pro22Arg) were determined too novel, and those were not detected in 105 healthy controls. A de novo missense mutation was found in a CMT family with the NEFL mutation. The frequency of the NEFL mutation was 2.4%, which was similar in Europeans, and lower than those found in Japanese. Pro22Arg and Glu397Lys mutations showed demyelinating neuropathy and Leu334pro mutation showed axonal neuropathy. Conclusions: We found NEFL mutations in patients with sporadic or dominantly inherited CMT. NEFL mutations should be considered in the evaluation of CMT or related neuropathies with various clinical features.
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mutational analysis of pmp22 mpz gjb1 egr2 and NEFL in korean charcot marie tooth neuropathy patients
Human Mutation, 2004Co-Authors: Byung-ok Choi, Ilnam Sunwoo, Misun Lee, Sang Hee Shin, Jung Hee Hwang, Kyoung Gyu Choi, Won Ki Kim, Nam Keun Kim, Ki Wha ChungAbstract:We examined CMT1A duplication of 17p11.2-p12, mutations of PMP22, MPZ (P0), GJB1 (Cx32), EGR2 and NEFL genes in 57 Korean families with patients diagnosed as having Charcot-Marie-Tooth (CMT) disease. The CMT1A duplication was present in 53.6% of 28 CMT type 1 patients. In the 42 CMT families without CMT1A duplication, 10 pathogenic mutations were found in 9 families. The 10 mutations were not detected in 105 healthy controls. Seven mutations (c.318delT (p.Ala106fs) in PMP22, c.352G>A (p.Asp118Asn), c.449-1G>T (3′-splice site), c.706A>G (p.Lys236Glu) in MPZ, c.408T>C (p.Val136Ala), c.502T>C (p.Cys168Arg) in GJB1, and c.1001T>C (p.Leu334Pro) in NEFL) were determined to be novel. The mutation frequencies of PMP22 and MPZ were similar to those found in several European populations, however, it appeared that mutations in GJB1 are less frequent in East Asian CMT patients than in Eur opean patients. We described the identified mutations and phenotype-genotype correlations based on nerve conduction studies. © 2004 Wiley-Liss, Inc.
Gregory C Shearer - One of the best experts on this subject based on the ideXlab platform.
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trafficking of nonesterified fatty acids in insulin resistance and relationship to dysglycemia
American Journal of Physiology-endocrinology and Metabolism, 2020Co-Authors: Rachel E Walker, Jennifer Lynn Ford, Raymond C Boston, Olga V Savinova, William S Harris, Michael H Green, Gregory C ShearerAbstract:In adipose, insulin functions to suppress intracellular lipolysis and secretion of nonesterified fatty acid (NEFA) into plasma. We applied glucose and NEFA minimal models (MM) following a frequently sampled intravenous glucose tolerance test (FSIVGTT) to assess glucose-specific and NEFA-specific insulin resistance. We used total NEFA and individual fatty acids in the NEFA MM, comparing the model parameters in metabolic syndrome (MetSyn) subjects (n = 52) with optimally healthy controls (OptHC; n = 14). Results are reported as mean difference (95% confidence interval). Using the glucose MM, MetSyn subjects had lower [-73% (-82, -57)] sensitivity to insulin (Si) and higher [138% (44, 293)] acute insulin response to glucose (AIRg). Using the NEFA MM, MetSyn subjects had lower [-24% (-35, -13)] percent suppression, higher [32% (15, 52)] threshold glucose (gs), and a higher [81% (12, 192)] affinity constant altering NEFA secretion (ϕ). Comparing fatty acids, percent suppression was lower in myristic acid (MA) than in all other fatty acids, and the stearic acid (SA) response was so unique that it did not fit the NEFA MM. MA and SA percent of total were increased at 50 min after glucose injection, whereas oleic acid (OA) and palmitic acid (PA) were decreased (P < 0.05). We conclude that the NEFA MM, as well as the response of individual NEFA fatty acids after a FSIVGTT, differ between OptHC and MetSyn subjects and that the NEFA MM parameters differ between individual fatty acids.
