The structure and function of the beta 2-adaptin appendage domain.
The heterotetrameric AP2 adaptor (alpha, beta 2, mu 2 and sigma 2 subunits) plays a central role in clathrin-mediated endocytosis. We present the protein recruitment function and 1.7 A resolution structure of its beta 2-appendage domain to complement those previously determined for the mu 2 subunit and alpha appendage. Using structure-directed mutagenesis, we demonstrate the ability of the beta 2 appendage alone to bind directly to clathrin and the accessory proteins AP180, epsin and eps15 at the same site. Clathrin polymerization is promoted by binding of clathrin simultaneously to the beta 2-appendage site and to a second site on the adjacent beta 2 hinge. This results in the displacement of the other ligands from the beta 2 appendage. Thus clathrin binding to an AP2-accessory protein complex would cause the controlled release of accessory proteins at sites of vesicle formation.
Owen
D J
DJ
MRC Laboratory of Molecular Biology, Hills Road, Cambridge, CB2 2QH, UK.
Vallis
Y
Y
Pearse
B M
BM
McMahon
H T
HT
Evans
P R
PR
D033966:Adaptor Protein Complex beta Subunits; D033981:Adaptor Protein Complex delta Subunits; D048868:Adaptor Proteins, Signal Transducing; D033942:Adaptor Proteins, Vesicular Transport; D000595:Amino Acid Sequence; D000818:Animals; D001665:Binding Sites; D001923:Brain Chemistry; D019556:COS Cells; D002135:Calcium-Binding Proteins / Q000737:chemistry / Q000378:metabolism; D002352:Carrier Proteins / Q000737:chemistry / Q000378:metabolism; D002942:Circular Dichroism; D002966:Clathrin / Q000737:chemistry / Q000648:ultrastructure; D018360:Crystallography, X-Ray; D018076:DNA, Complementary / Q000378:metabolism; D004705:Endocytosis; D005982:Glutathione Transferase / Q000378:metabolism; D006801:Humans; D007150:Immunohistochemistry; D047908:Intracellular Signaling Peptides and Proteins; D008565:Membrane Proteins / Q000737:chemistry*; D008854:Microscopy, Electron; D008958:Models, Molecular; D008969:Molecular Sequence Data; D016297:Mutagenesis, Site-Directed; D009479:Neuropeptides / Q000737:chemistry / Q000378:metabolism; D010750:Phosphoproteins / Q000737:chemistry / Q000378:metabolism; D017433:Protein Structure, Secondary; D017434:Protein Structure, Tertiary; D011993:Recombinant Fusion Proteins / Q000737:chemistry; D017386:Sequence Homology, Amino Acid; D013329:Structure-Activity Relationship; D013552:Swine; D033921:Vesicular Transport Proteins
D033966:Adaptor Protein Complex beta Subunits; D033981:Adaptor Protein Complex delta Subunits; D048868:Adaptor Proteins, Signal Transducing; D033942:Adaptor Proteins, Vesicular Transport; D002135:Calcium-Binding Proteins; D002352:Carrier Proteins; D002966:Clathrin; D018076:DNA, Complementary; C486206:EPS15 protein, human; D047908:Intracellular Signaling Peptides and Proteins; D008565:Membrane Proteins; D009479:Neuropeptides; D010750:Phosphoproteins; D011993:Recombinant Fusion Proteins; D033921:Vesicular Transport Proteins; C114154:epsin; D005982:Glutathione Transferase