title: The beta 1 and beta 2 subunits of the AP complexes are the clathrin coat assembly components.
abstract: The beta 1 and beta 2 subunits are the closely-related large chains of the trans-Golgi network AP-1 and the plasma membrane AP-2 clathrin-associated protein complexes, respectively. Recombinant beta 1 and beta 2 subunits have been generated in Escherichia coli. It was found that, in the absence of all the other AP subunits, beta 1 and beta 2 interact with clathrin and drive the efficient assembly of clathrin coats. In addition, beta 2 subunits and AP complexes compete for the same clathrin binding site. The appearance of the clathrin/beta coats is the same as the barrel-shaped structures formed with native AP complexes. It is proposed that the principal function of the beta subunits is to initiate coat formation, while the remaining subunits of the AP complexes have other roles in coated pit and coated vesicle function.
authors.affiliation: Harvard Medical School, Department of Cell Biology, Boston, MA 02115.
authors.forename: A
authors.initials: A
authors.lastname: Gallusser
authors.forename: T
authors.initials: T
authors.lastname: Kirchhausen
mesh_terms: D033942:Adaptor Proteins, Vesicular Transport; D000818:Animals; D001483:Base Sequence; D002966:Clathrin / Q000378:metabolism*; D003001:Cloning, Molecular; D003034:Coated Pits, Cell-Membrane / Q000648:ultrastructure*; D017931:DNA Primers / Q000737:chemistry; D007425:Intracellular Membranes / Q000378:metabolism / Q000648:ultrastructure; D008854:Microscopy, Electron; D008969:Molecular Sequence Data; D009419:Nerve Tissue Proteins / Q000378:metabolism*; D015388:Organelles / Q000378:metabolism / Q000648:ultrastructure; D010750:Phosphoproteins / Q000378:metabolism*; D011485:Protein Binding; D051381:Rats; D011994:Recombinant Proteins; D013329:Structure-Activity Relationship
chemical_list: D033942:Adaptor Proteins, Vesicular Transport; D002966:Clathrin; D017931:DNA Primers; D009419:Nerve Tissue Proteins; D010750:Phosphoproteins; D011994:Recombinant Proteins