Golgi Associated Gamma Adaptin Ear Containing ARF Binding Protein 1 (GgA1)

GGA1 encodes a member of the Golgi-localized, gamma adaptin ear-containing, ARF-binding (GGA) protein family. Members of this family are ubiquitous coat proteins that regulate the trafficking of proteins between the trans-Golgi network and the lysosome. These proteins share an amino-terminal VHS domain which mediates sorting of the mannose 6-phosphate receptors at the trans-Golgi network. They also contain a carboxy-terminal region with homology to the ear domain of gamma-adaptins. Multiple alternatively spliced transcript variants encoding different isoforms have been found for this gene. GGA1 and GGA2 also are not associated with each other, although they colocalize on perinuclear membranes.The GGA1 gene expresses a 70-kD protein that shares 45% sequence identity with GGA2 and GGA3.