TY - JOUR
T1 - Multisubunit assembly of an integral plasma membrane channel protein, gap junction connexin43, occurs after exit from the ER
AU - Musil, Linda S.
AU - Goodenough, Daniel A.
PY - 1993/9/24
Y1 - 1993/9/24
N2 - Connexin43 (Cx43) is an integral plasma membrane protein that forms gap junctions between vertebrate cells. We have used sucrose gradient fractionation and chemical cross-linking to study the first step in gap junction assembly, oligomerization of Cx43 monomers into connexon channels. In contrast with other plasma membrane proteins, multisubunit assembly of Cx43 was specifically and completely blocked when endoplasmic reticulum (ER)-to-Golgi transport was inhibited by 15°C incubation, carbonyl cyanide m-chlorophenylhydrazone, or brefeldin A or in CHO cell mutants with temperature-sensitive defects in secretion. Additional experiments indicated that connexon assembly occurred intracellularly, most likely in the trans-Golgi network. These results describe a post-ER assembly pathway for integral membrane proteins and have implications for the relationship between membrane protein oligomerization and intracellular transport.
AB - Connexin43 (Cx43) is an integral plasma membrane protein that forms gap junctions between vertebrate cells. We have used sucrose gradient fractionation and chemical cross-linking to study the first step in gap junction assembly, oligomerization of Cx43 monomers into connexon channels. In contrast with other plasma membrane proteins, multisubunit assembly of Cx43 was specifically and completely blocked when endoplasmic reticulum (ER)-to-Golgi transport was inhibited by 15°C incubation, carbonyl cyanide m-chlorophenylhydrazone, or brefeldin A or in CHO cell mutants with temperature-sensitive defects in secretion. Additional experiments indicated that connexon assembly occurred intracellularly, most likely in the trans-Golgi network. These results describe a post-ER assembly pathway for integral membrane proteins and have implications for the relationship between membrane protein oligomerization and intracellular transport.
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U2 - 10.1016/0092-8674(93)90728-9
DO - 10.1016/0092-8674(93)90728-9
M3 - Article
C2 - 7691412
AN - SCOPUS:0027364529
VL - 74
SP - 1065
EP - 1077
JO - Cell
JF - Cell
SN - 0092-8674
IS - 6
ER -