Gamma subunit of the AP-1 adaptor complex binds clathrin: implications for cooperative binding in coated vesicle assembly
- PMID: 11451993
- PMCID: PMC55640
- DOI: 10.1091/mbc.12.7.1925
Gamma subunit of the AP-1 adaptor complex binds clathrin: implications for cooperative binding in coated vesicle assembly
Abstract
The heterotetrameric AP-1 adaptor complex is involved in the assembly of clathrin-coated vesicles originating from the trans-Golgi network (TGN). The beta 1 subunit of AP-1 is known to contain a consensus clathrin binding sequence, LLNLD (the so-called clathrin box motif), in its hinge segment through which the beta chain interacts with the N-terminal domains of clathrin trimers. Here, we report that the hinge region of the gamma subunit of human and mouse AP-1 contains two copies of a new variant, LLDLL, of the clathrin box motif that also bind to the terminal domain of the clathrin heavy chain. High-affinity binding of the gamma hinge to clathrin trimers requires both LLDLL sequences to be present and the spacing between them to be maintained. We also identify an independent clathrin-binding site within the appendage domain of the gamma subunit that interacts with a region of clathrin other than the N-terminal domain. Clathrin polymerization is promoted by glutathione S-transferase (GST)-gamma hinge, but not by GST-gamma appendage. However, the hinge and appendage domains of gamma function in a cooperative manner to recruit and polymerize clathrin, suggesting that clathrin lattice assembly at the TGN involves multivalent binding of clathrin by the gamma and beta1 subunits of AP-1.
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References
-
- Ahle S, Ungewickell E. Identification of a clathrin binding subunit in the HA2 adaptor protein complex. J Biol Chem. 1989;264:20089–20093. - PubMed
-
- Dell'Angelica EC, Klumperman J, Stoorvogel W, Bonifacino JS. Association of the AP-3 adaptor complex with clathrin. Science. 1998;280:431–434. - PubMed
-
- Drake MT, Downs MA, Traub LM. Epsin binds to clathrin by associating directly with the clathrin terminal domain. J Biol Chem. 2000;275:6479–6489. - PubMed
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