The role of the cytoskeleton in the formation of gap junctions by Connexin 30.
Mutations in the genes that encode Connexin 26 (GJB2) and Connexin 30 (GJB6) are the most common known cause of hereditary nonsyndromic sensorineural deafness. Cx26 and Cx30 share a similar protein structure, as well as the same expression distribution pattern in the cochlea. Cx26 has different intracellular trafficking properties compared to those of Cx43 and Cx32, whose trafficking manner is consistent with the classical membrane protein secretory pathway. Until now, however, the trafficking patterns of Cx30 have not been studied. By means of an immunofluorescence staining approach, we found that the targeting of Cx30 to gap junctions in transfected HeLa cells is not affected by brefeldin A, suggesting a Golgi-independent feature, similar to Cx26. Nocodazole had a minimal effect on assembly and distribution of Cx30 gap junctions. Cytochalasin B-induced actin filament depolymerization, however, affected both the pattern and the distribution of Cx30 gap junctions. Co-localization with and/or interaction between Cx30 and microtubules and cortical actin filaments, but not with the tight/adherens junction protein ZO-1, was confirmed by immunofluorescence and/or immunoprecipitation methods. The results suggest that the cytoskeleton, and especially actin filaments, are important components in the processes of assembly, trafficking and stabilization of Cx30 gap junctions.
Qu
Chunyan
C
Department of Pathology, Stanford University School of Medicine, Stanford, CA, USA.
Gardner
Phyllis
P
Schrijver
Iris
I
D008841:Actin Cytoskeleton / Q000187:drug effects / Q000378:metabolism; D000199:Actins / Q000378:metabolism; D020126:Brefeldin A / Q000494:pharmacology; D000072259:Connexin 26; D000075302:Connexin 30; D017630:Connexins / Q000378:metabolism*; D003571:Cytochalasin B / Q000494:pharmacology; D003599:Cytoskeleton / Q000187:drug effects / Q000378:metabolism*; D004305:Dose-Response Relationship, Drug; D017629:Gap Junctions / Q000187:drug effects / Q000378:metabolism*; D006367:HeLa Cells; D006801:Humans; D047468:Immunoprecipitation; D008565:Membrane Proteins / Q000378:metabolism; D015739:Nocodazole / Q000494:pharmacology; D010750:Phosphoproteins / Q000378:metabolism; D011485:Protein Binding / Q000187:drug effects; D021381:Protein Transport / Q000187:drug effects; D055571:Secretory Pathway / Q000187:drug effects; D014162:Transfection; D014404:Tubulin / Q000378:metabolism; D062826:Zonula Occludens-1 Protein
D000199:Actins; D000075302:Connexin 30; D017630:Connexins; C000607042:GJB2 protein, human; C491020:GJB6 protein, human; D008565:Membrane Proteins; D010750:Phosphoproteins; C569042:TJP1 protein, human; D014404:Tubulin; D062826:Zonula Occludens-1 Protein; D000072259:Connexin 26; D020126:Brefeldin A; D003571:Cytochalasin B; D015739:Nocodazole