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Vertebrate Claudin/PMP22/EMP22/MP20 family protein TMEM47 regulates epithelial cell junction maturation and morphogenesis
Author(s) -
Dong Yi,
Simske Jeffrey S.
Publication year - 2016
Publication title -
developmental dynamics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.634
H-Index - 141
eISSN - 1097-0177
pISSN - 1058-8388
DOI - 10.1002/dvdy.24404
Subject(s) - adherens junction , tight junction , microbiology and biotechnology , claudin , biology , cadherin , cell junction , septate junctions , cell polarity , immunoprecipitation , fyn , cell adhesion , cell , gap junction , signal transduction , cell culture , genetics , proto oncogene tyrosine protein kinase src , intracellular
Background: TMEM47 is the vertebrate orthologue of C. elegans VAB‐9, a tetraspan adherens junction protein in the PMP22/EMP/Claudin family of proteins. VAB‐9 regulates cell morphology and adhesion in C. elegan s and TMEM47 is expressed during kidney development and regulates the activity of Fyn. The conserved functions of VAB‐9 and TMEM47 are not well understood. Results: expression of TMEM47 in C. elegans functionally rescues vab‐9 mutations. Unlike Claudins, expression of TMEM47 in L fibroblasts does not generate tight junction strands; instead, membrane localization requires E‐cadherin expression. Temporally, TMEM47 localizes at cell junctions first with E‐cadherin before ZO‐1 colocalization and in polarized epithelia, TMEM47 colocalizes with adherens junction proteins. By immunoprecipitation, TMEM47 associates with classical adherens junction proteins, but also with tight junction proteins Par6B and aPKCλ. Over‐expression of TMEM47 in MDCK cells decreases apical surface area, increases activated myosin light chain at cell–cell contacts, disrupts cell polarity and morphology, delays cell junction reassembly following calcium switch, and selectively interferes with tight junction assembly. Reduced TMEM47 expression results in opposite phenotypes. Conclusions: TMEM47 regulates the localization of a subset of tight junction proteins, associated actomyosin structures, cell morphology, and participates in developmental transitions from adherens to tight junctions. Developmental Dynamics 245:653–666, 2016 . © 2016 Wiley Periodicals, Inc.