Caveolin-1 and -2 interact with connexin43 and regulate gap junctional intercellular communication in keratinocytes.
Connexin43 (Cx43) has been reported to interact with caveolin (Cav)-1, but the role of this association and whether other members of the caveolin family bind Cx43 had yet to be established. In this study, we show that Cx43 coimmunoprecipitates and colocalizes with Cav-1 and Cav-2 in rat epidermal keratinocytes. The colocalization of Cx43 with Cav-1 was confirmed in keratinocytes from human epidermis in vivo. Our mutation and Far Western analyses revealed that the C-terminal tail of Cx43 is required for its association with Cavs and that the Cx43/Cav-1 interaction is direct. Our results indicate that newly synthesized Cx43 interacts with Cavs in the Golgi apparatus and that the Cx43/Cavs complex also exists at the plasma membrane in lipid rafts. Using overexpression and small interfering RNA approaches, we demonstrated that caveolins regulate gap junctional intercellular communication (GJIC) and that the presence of Cx43 in lipid raft domains may contribute to the mechanism modulating GJIC. Our results suggest that the Cx43/Cavs association occurs during exocytic transport, and they clearly indicate that caveolin regulates GJIC.
Langlois
Stéphanie
S
Department of Anatomy and Cell Biology, University of Western Ontario, London, ON N6A 5C1, Canada.
Cowan
Kyle N
KN
Shao
Qing
Q
Cowan
Bryce J
BJ
Laird
Dale W
DW
D000818:Animals; D051242:Caveolin 1 / Q000378:metabolism*; D051243:Caveolin 2 / Q000378:metabolism*; D002450:Cell Communication; D002451:Cell Compartmentation; D002478:Cells, Cultured; D018031:Connexin 43 / Q000737:chemistry / Q000378:metabolism*; D000078404:Epidermal Cells; D017629:Gap Junctions / Q000378:metabolism*; D006056:Golgi Apparatus / Q000378:metabolism; D006801:Humans; D047468:Immunoprecipitation; D042541:Intracellular Space / Q000378:metabolism; D015603:Keratinocytes / Q000166:cytology* / Q000378:metabolism*; D021962:Membrane Microdomains / Q000378:metabolism; D011485:Protein Binding; D021381:Protein Transport; D034741:RNA, Small Interfering / Q000378:metabolism; D051381:Rats; D013329:Structure-Activity Relationship
D051242:Caveolin 1; D051243:Caveolin 2; D018031:Connexin 43; D034741:RNA, Small Interfering