InterPro domain: IPR037992

Trs33 (corresponding to human homologues TRAPPC6A and TRAPPC6B) is a subunit of the trafficking protein particle complex (TRAPP). Transport protein particle (TRAPP) complexes are multimeric guanine nucleotide-exchange factors for the GTPase Ypt1. Trs33 is one of the core subunits of TRAPP complexes which play a key role in the regulation of ER-to-Golgi and intra-Golgi transport by tethering the vesicle membrane to the target membrane [ 1 ]. In yeast, it is a core component of TRAPP complexes I, II and IV. Complex IV is thought to be involved in autophagy [ 2 ]. In mammals, mutations in TRAPPC6a cause mosaic loss of coat pigment [ 3 ].

1. TRAPP complexes in membrane traffic: convergence through a common Rab. Nat. Rev. Mol. Cell Biol. 11, 759-63
2. Trs33-Containing TRAPP IV: A Novel Autophagy-Specific Ypt1 GEF. Genetics 204, 1117-1128
3. A mouse TRAPP-related protein is involved in pigmentation. Genomics 88, 196-203