Spatially regulated recruitment of clathrin to the plasma membrane during capping and cell translocation.
Clathrin-coated vesicles bud from selected cellular membranes to traffic-specific intracellular proteins. To study the dynamic properties of clathrin-coated membranes, we expressed clathrin heavy chain tagged with green fluorescent protein (GFP) in Dictyostelium cells. GFP-clathrin was functional and retained the native properties of clathrin: the chimeric protein formed classic clathrin lattices on cellular membranes and also rescued phenotypic defects of clathrin null cells. GFP-clathrin distributed into punctate loci found throughout the cytoplasm, on the plasma membrane, and concentrated to a perinuclear location. These clathrin-coated structures were remarkably motile and capable of rapid and bidirectional transport across the cell. We identified two local domains of the plasma membrane as sites for clathrin recruitment in motile cells. First, as cells translocated or changed shape and retracted their tails, clathrin was transiently concentrated on the membrane at the back of the cell tail. Second, as cells capped their cell surface receptors, clathrin was recruited locally to the membrane under the tight cap of cross-linked receptors. This suggests that local sites for clathrin polymerization on specific domains of the plasma membrane undergo rapid and dynamic regulation in motile cells.
Damer
C K
CK
Department of Biology, Vassar College, Poughkeepsie, New York 12604, USA.
O'Halloran
T J
TJ
D000818:Animals; D001692:Biological Transport / Q000502:physiology; D002455:Cell Division; D002462:Cell Membrane / Q000378:metabolism; D002966:Clathrin / Q000235:genetics / Q000378:metabolism* / Q000502:physiology; D033922:Clathrin Heavy Chains; D004023:Dictyostelium / Q000378:metabolism / Q000502:physiology; D015870:Gene Expression; D049452:Green Fluorescent Proteins; D008164:Luminescent Proteins / Q000235:genetics / Q000378:metabolism; D010587:Phagocytosis / Q000502:physiology; D011956:Receptors, Cell Surface / Q000378:metabolism; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000378:metabolism / Q000502:physiology
D002966:Clathrin; D008164:Luminescent Proteins; D011956:Receptors, Cell Surface; D011993:Recombinant Fusion Proteins; D033922:Clathrin Heavy Chains; D049452:Green Fluorescent Proteins