Remodeling the cell surface distribution of membrane proteins during the development of epithelial cell polarity.
The development of polarized epithelial cells from unpolarized precursor cells follows induction of cell-cell contacts and requires resorting of proteins into different membrane domains. We show that in MDCK cells the distributions of two membrane proteins, Dg-1 and E-cadherin, become restricted to the basal-lateral membrane domain within 8 h of cell-cell contact. During this time, however, 60-80% of newly synthesized Dg-1 and E-cadherin is delivered directly to the forming apical membrane and then rapidly removed, while the remainder is delivered to the basal-lateral membrane and has a longer residence time. Direct delivery of greater than 95% of these proteins from the Golgi complex to the basal-lateral membrane occurs greater than 48 h later. In contrast, we show that two apical proteins are efficiently delivered and restricted to the apical cell surface within 2 h after cell-cell contact. These results provide insight into mechanisms involved in the development of epithelial cell surface polarity, and the establishment of protein sorting pathways in polarized cells.
Wollner
D A
DA
Department of Molecular and Cellular Physiology, Stanford University School of Medicine, California 94305-5426.
Krzeminski
K A
KA
Nelson
W J
WJ
D000818:Animals; D001710:Biotin / Q000378:metabolism; D015820:Cadherins / Q000378:metabolism; D015815:Cell Adhesion Molecules / Q000737:chemistry / Q000378:metabolism*; D002450:Cell Communication; D002460:Cell Line; D002462:Cell Membrane / Q000378:metabolism*; D016764:Cell Polarity / Q000502:physiology*; D006056:Golgi Apparatus / Q000378:metabolism; D007700:Kinetics
D015820:Cadherins; D015815:Cell Adhesion Molecules; D001710:Biotin