Mechanism of recruiting Sec6/8 (exocyst) complex to the apical junctional complex during polarization of epithelial cells.
Sec6/8 (exocyst) complex regulates vesicle delivery and polarized membrane growth in a variety of cells, but mechanisms regulating Sec6/8 localization are unknown. In epithelial cells, Sec6/8 complex is recruited to cell-cell contacts with a mixture of junctional proteins, but then sorts out to the apex of the lateral membrane with components of tight junction and nectin complexes. Sec6/8 complex fractionates in a high molecular mass complex with tight junction proteins and a portion of E-cadherin, and co-immunoprecipitates with cell surface-labeled E-cadherin and nectin-2alpha. Recruitment of Sec6/8 complex to cell-cell contacts can be achieved in fibroblasts when E-cadherin and nectin-2alpha are co-expressed. These results support a model in which localized recruitment of Sec6/8 complex to the plasma membrane by specific cell-cell adhesion complexes defines a site for vesicle delivery and polarized membrane growth during development of epithelial cell polarity.
Yeaman
Charles
C
Department of Molecular and Cellular Physiology, Beckman Center for Molecular and Genetic Medicine, Stanford University School of Medicine, Stanford, CA 94305-5345, USA. charles-yeaman@uiowa.edu
Grindstaff
Kent K
KK
Nelson
W James
WJ
D000818:Animals; D002352:Carrier Proteins / Q000378:metabolism*; D002448:Cell Adhesion / Q000502:physiology; D015815:Cell Adhesion Molecules / Q000302:isolation & purification / Q000502:physiology*; D002460:Cell Line; D016764:Cell Polarity / Q000502:physiology*; D004285:Dogs; D004847:Epithelial Cells / Q000502:physiology*; D007425:Intracellular Membranes / Q000502:physiology; D007668:Kidney / Q000166:cytology; D046911:Macromolecular Substances
D002352:Carrier Proteins; D015815:Cell Adhesion Molecules; D046911:Macromolecular Substances