FunctionPlays a role in protein sorting and trafficking between the trans-Golgi network (TGN) and endosomes. Mediates the ARF-dependent recruitment of clathrin to the TGN and binds ubiquitinated proteins and membrane cargo molecules with a cytosolic acidic cluster-dileucine (AC-LL) motif.
Tissue specificityUbiquitously expressed.
Sequence similaritiesBelongs to the GGA protein family. Contains 1 GAE domain. Contains 1 GAT domain. Contains 1 VHS domain.
DomainThe VHS domain functions as a recognition module for sorting signals composed of an acidic cluster followed by two leucines (AC-LL motif). The GAT domain is responsible for interaction with ARF-GTP, UBC and RABEP1. Required for recruitment to the TGN it prevents ARF-GTP hydrolysis. The unstructured hinge region contains clathrin-binding but no autoinhibitory (AC-LL) motifs. The GAE domain binds accessory proteins regulating GGAs function.
Post-translational modificationsPhosphorylated by CK2 and dephosphorylated by PP2A. Phosphorylation of GGA1 allows the internal AC-LL motif to bind the VHS domain and to inhibit the recognition of cargo signals. Phosphorylated upon DNA damage, probably by ATM or ATR. Ubiquitinated.