Auxilin-dynamin interactions link the uncoating ATPase chaperone machinery with vesicle formation.
The large GTPase dynamin is required for budding of clathrin-coated vesicles from the plasma membrane, after which the clathrin coat is removed by the chaperone Hsc70 and its cochaperone auxilin. Recent evidence suggests that the GTP-bound form of dynamin may recruit factors that execute the fission reaction. Here, we show that dynamin:GTP binds to Hsc70 and auxilin. We mapped two domains within auxilin that interact with dynamin, and these domains inhibit endocytosis when overexpressed in HeLa cells or when added in a permeable cell assay. The inhibition is not due to impairment of clathrin uncoating or to altered clathrin distribution in cells. Thus, in addition to its requirement for clathrin uncoating, our results show that auxilin also acts during the early steps of clathrin-coated vesicle formation. The data suggest that dynamin regulates the action of molecular chaperones in vesicle budding during endocytosis.
Newmyer
Sherri L
SL
G.W. Hooper Foundation, The University of California, San Francisco, San Francisco, CA 94143, USA.
Christensen
Arne
A
Sever
Sanja
S
D000251:Adenosine Triphosphatases / Q000378:metabolism*; D000256:Adenoviridae / Q000235:genetics; D034021:Auxilins / Q000737:chemistry / Q000378:metabolism*; D001665:Binding Sites; D002352:Carrier Proteins; D022163:Clathrin-Coated Vesicles / Q000378:metabolism; D034281:Dynamins / Q000378:metabolism*; D004705:Endocytosis; D019204:GTP-Binding Proteins / Q000378:metabolism; D005982:Glutathione Transferase / Q000378:metabolism; D006160:Guanosine Triphosphate / Q000378:metabolism; D050883:HSC70 Heat-Shock Proteins; D018840:HSP70 Heat-Shock Proteins / Q000378:metabolism; D006367:HeLa Cells; D006801:Humans; D007700:Kinetics; D008954:Models, Biological; D017434:Protein Structure, Tertiary; D011994:Recombinant Proteins / Q000378:metabolism
D034021:Auxilins; D002352:Carrier Proteins; D050883:HSC70 Heat-Shock Proteins; D018840:HSP70 Heat-Shock Proteins; C494371:HSPA8 protein, human; D011994:Recombinant Proteins; D006160:Guanosine Triphosphate; D005982:Glutathione Transferase; D000251:Adenosine Triphosphatases; D019204:GTP-Binding Proteins; D034281:Dynamins