Role of auxilin in uncoating clathrin-coated vesicles.
Clathrin-coated vesicles transport selected integral membrane proteins from the cell surface and the trans-Golgi network to the endosomal system. Before fusing with their target the vesicles must be stripped of their coats. This process is effected by the chaperone protein hsp70c together with a 100K cofactor which we here identify as the coat protein auxilin. Auxilin binds with high affinity to assembled clathrin lattices and, in the presence of ATP, recruits hsp70c. Dissociation of the lattice does not depend as previously supposed on clathrin light chains or on the amino-terminal domain of the heavy chain. The presence of a J-domain at its carboxy terminus now defines auxilin as a member of the DnaJ protein family. In conjunction with hsp70, DnaJ proteins catalyse protein folding, protein transport across membranes and the selective disruption of protein-protein interactions. We show that deletion of the J-domain of auxilin results in the loss of cofactor activity.
Ungewickell
E
E
Department of Pathology, Washington University School of Medicine, St Louis, Missouri 63110, USA.
Ungewickell
H
H
Holstein
S E
SE
Lindner
R
R
Prasad
K
K
Barouch
W
W
Martin
B
B
Greene
L E
LE
Eisenberg
E
E
D033942:Adaptor Proteins, Vesicular Transport; D000255:Adenosine Triphosphate / Q000378:metabolism; D000595:Amino Acid Sequence; D000818:Animals; D002417:Cattle; D002966:Clathrin / Q000378:metabolism*; D018699:Coated Vesicles / Q000378:metabolism*; D050956:HSP40 Heat-Shock Proteins; D018840:HSP70 Heat-Shock Proteins / Q000378:metabolism; D006360:Heat-Shock Proteins / Q000378:metabolism; D007700:Kinetics; D008969:Molecular Sequence Data; D009419:Nerve Tissue Proteins / Q000737:chemistry / Q000378:metabolism / Q000502:physiology*; D010750:Phosphoproteins / Q000737:chemistry / Q000378:metabolism / Q000502:physiology*
D033942:Adaptor Proteins, Vesicular Transport; D002966:Clathrin; D050956:HSP40 Heat-Shock Proteins; D018840:HSP70 Heat-Shock Proteins; D006360:Heat-Shock Proteins; D009419:Nerve Tissue Proteins; D010750:Phosphoproteins; D000255:Adenosine Triphosphate