Regulation of clathrin assembly and trimerization defined using recombinant triskelion hubs.
Clathrin polymerization into a polyhedral vesicle coat drives receptor sorting at cellular membranes during endocytosis and organelle biogenesis. To study clathrin self-assembly, we expressed the C-terminal third of the clathrin heavy chain in bacteria. The recombinant fragment trimerized, bound clathrin light chains, and morphologically resembled the hub domain of the triskelion-shaped clathrin molecule. Self-assembly of recombinant hubs demonstrated a regulatory role for clathrin light chains and for the distal portions of triskelion legs in clathrin coat formation. Deletion mutagenesis of the hub localized a domain mediating light chain binding and clathrin self-assembly and mapped a transferable trimerization domain. These studies define molecular interactions controlling clathrin self-assembly and establish a recombinant system for future analysis.
Liu
S H
SH
Department of Pharmacy, School of Pharmacy, University of California, San Francisco 94143-0552, USA.
Wong
M L
ML
Craik
C S
CS
Brodsky
F M
FM
D000818:Animals; D002417:Cattle; D002966:Clathrin / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism / Q000648:ultrastructure; D004926:Escherichia coli / Q000235:genetics; D005136:Eye Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism / Q000648:ultrastructure; D006801:Humans; D008958:Models, Molecular; D008969:Molecular Sequence Data; D010446:Peptide Fragments / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D011487:Protein Conformation; D017510:Protein Folding; D011994:Recombinant Proteins / Q000737:chemistry / Q000378:metabolism; D013329:Structure-Activity Relationship
D002966:Clathrin; D005136:Eye Proteins; D010446:Peptide Fragments; D011994:Recombinant Proteins