Connexin and gap junction degradation.
Many of the subunit proteins (connexins) that form gap junctions are rather dynamic, with half-lives of only a few hours. Thus, alterations in connexin turnover and degradation may represent significant mechanisms for the regulation of intercellular communication. We describe a pharmacological approach to determining pathways of connexin degradation. Cell cultures are left untreated or treated with inhibitors of lysosomal or proteasomal proteolysis. Changes in connexin levels, localization, or decay curves (derived from pulse-chase experiments) are assessed by immunoblotting, immunofluorescence, and immunoprecipitation, respectively. Such experiments have provided evidence that connexin43 degradation involves both the lysosome and the proteasome.
Berthoud
V M
VM
Department of Pediatrics, University of Chicago, Chicago, Illinois 60637-1470, USA.
Tadros
P N
PN
Beyer
E C
EC
D000818:Animals; D002450:Cell Communication; D002478:Cells, Cultured; D017630:Connexins / Q000032:analysis / Q000378:metabolism*; D003546:Cysteine Endopeptidases / Q000378:metabolism; D004591:Electrophoresis, Polyacrylamide Gel / Q000379:methods; D017629:Gap Junctions / Q000502:physiology* / Q000648:ultrastructure; D006706:Homeostasis; D007118:Immunoassay / Q000379:methods; D008854:Microscopy, Electron / Q000379:methods; D009097:Multienzyme Complexes / Q000378:metabolism; D046988:Proteasome Endopeptidase Complex; D011865:Radioisotope Dilution Technique
D017630:Connexins; D009097:Multienzyme Complexes; D003546:Cysteine Endopeptidases; D046988:Proteasome Endopeptidase Complex