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Inhibition of ZO‐1 interaction alters the subcellular localization of the endothelial connexins Cx43 and Cx40 but not Cx37 in arterioles of the hamster cheek pouch
Author(s) -
Rivers Richard J,
Wolfle Stephanie
Publication year - 2008
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.22.2_supplement.62
Subject(s) - cheek pouch , connexin , microbiology and biotechnology , hamster , endothelium , endothelial stem cell , chemistry , fluorescence microscope , biology , subcellular localization , chinese hamster ovary cell , gap junction , cytoplasm , biochemistry , intracellular , fluorescence , in vitro , receptor , genetics , physics , quantum mechanics
Connexins (Cx) coordinate vascular behaviour by coupling vascular cells. The extent of coupling is altered by protein turnover or interaction with regulatory proteins. In cell culture, expression of a Cx‐binding ZO‐1 fragment (ZO1‐frag) (aa 4 – 445 of ZO‐1) can displace Cx43 by inhibiting interaction between ZO‐1 scaffold protein and Cx43. We therefore studied the effect of expression of ZO‐1‐frag on the subcellular localization of the vascular connexins Cx40, Cx43 and Cx37 in arteriolar endothelium. ZO1‐frag was expressed in the hamster cheek pouch using an endothelium specific promoter (ICAM2) and adenoviral gene‐transfer. Control experiments were performed with a vector coding for a fluorescent dye. After one day of infection pouches of the anesthetized hamster were excised, prepared for whole mount immunohistochemistry, and studied with fluorescent microscopy. Antibody labelling for Cx37, Cx40 and Cx43 exhibited punctate staining at the cell‐borders of arteriolar EC. Expression of ZO1‐frag protein had a variable effect on connexin distribution. Whereas Cx43 and Cx40 seemed to be reduced below detection level in EC‐membranes, localization of Cx37 to the membrane was unchanged. These novel findings indicate a differential regulation of vascular connexin proteins in vivo. ZO‐1 may therefore be a new and important regulatory protein in vascular gap junctional communication. Supported by NIH R01HL72922