Ap4s1 - adaptor-related protein complex AP-4, sigma 1

This gene encodes the sigma subunit of the adaptor-related protein complex 4 which mediates intracellular membrane trafficking along the endocytic and secretory transport pathways. This complex contains four subunits, beta, epsilon, mu, and sigma, and belongs to a family of five adapter protein complexes, including three clathrin-associated complexes and two non clathrin-associated complexes, that localize to different intracellular compartments and mediate membrane vesicle trafficking using distinct pathways. In humans, loss-of-function mutations in this gene have been linked to specific adapter complex 4 deficiency disorders including hereditary spastic paraplegia. Alternate splicing results in multiple transcript variants. [provided by RefSeq, Jul 2016]