Sec6/8 complex is recruited to cell-cell contacts and specifies transport vesicle delivery to the basal-lateral membrane in epithelial cells.
In budding yeast, the Sec6/8p complex is essential for generating cell polarity by specifying vesicle delivery to the bud tip. We show that Sec6/8 homologs are components of a cytosolic, approximately 17S complex in nonpolarized MDCK epithelial cells. Upon initiation of calcium-dependent cell-cell adhesion, approximately 70% of Sec6/8 is rapidly (t(1/2) approximately 3-6 hr) recruited to sites of cell-cell contact. In streptolysin-O-permeabilized MDCK cells, Sec8 antibodies inhibit delivery of LDL receptor to the basal-lateral membrane, but not p75NTR to the apical membrane. These results indicate that lateral membrane recruitment of the Sec6/8 complex is a consequence of cell-cell adhesion and is essential for the biogenesis of epithelial cell surface polarity.
Grindstaff
K K
KK
Department of Molecular and Cellular Physiology, Stanford University School of Medicine, California 94305-5345, USA.
Yeaman
C
C
Anandasabapathy
N
N
Hsu
S C
SC
Rodriguez-Boulan
E
E
Scheller
R H
RH
Nelson
W J
WJ
D000818:Animals; D001692:Biological Transport; D002352:Carrier Proteins / Q000378:metabolism*; D015815:Cell Adhesion Molecules / Q000378:metabolism*; D002451:Cell Compartmentation; D002462:Cell Membrane / Q000378:metabolism; D016764:Cell Polarity / Q000502:physiology*; D004285:Dogs; D004847:Epithelial Cells / Q000378:metabolism*; D006056:Golgi Apparatus / Q000378:metabolism; D007365:Intercellular Junctions / Q000502:physiology*; D007425:Intracellular Membranes / Q000378:metabolism; D007668:Kidney / Q000166:cytology; D008077:Lipoproteins, LDL / Q000378:metabolism; D008970:Molecular Weight; D009414:Nerve Growth Factors / Q000378:metabolism; D011485:Protein Binding
D002352:Carrier Proteins; D015815:Cell Adhesion Molecules; D008077:Lipoproteins, LDL; D009414:Nerve Growth Factors