AP4S1

Adaptor-related protein complex 4, sigma 1 subunit
Identifiers
Symbols	AP4S1 ; AP47B; CLA20; CLAPS4; CPSQ6; SPG52
External IDs	OMIM: 607243 MGI: 1337065 HomoloGene: 32513 GeneCards: AP4S1 Gene
Gene ontology Molecular function • transporter activity • protein transporter activity Cellular component • coated pit • endosome lumen • trans-Golgi network membrane Biological process • post-Golgi vesicle-mediated transport • protein transport • membrane organization Sources: Amigo / QuickGO
Orthologs
Species	Human	Mouse
Entrez	11154	11782
Ensembl	ENSG00000100478	ENSMUSG00000020955
UniProt	Q9Y587	Q9WVL1
RefSeq (mRNA)	NM_001128126	NM_021710
RefSeq (protein)	NP_001121598	NP_068356
Location (UCSC)	Chr 14: 31.03 – 31.1 Mb	Chr 12: 51.69 – 51.74 Mb
PubMed search

AP-4 complex subunit sigma-1 is a protein that in humans is encoded by the AP4S1 gene.^[1]

Function

The heterotetrameric adaptor protein (AP) complexes sort integral membrane proteins at various stages of the endocytic and secretory pathways. AP4 is composed of 2 large chains, beta-4 (AP4B1) and epsilon-4 (AP4E1), a medium chain, mu-4 (AP4M1), and a small chain, sigma-4 (AP4S1, this gene).^[1]

Clinical relevance

It is currently hypothesized that AP4-complex-mediated trafficking plays a crucial role in brain development and functioning.^[2]

References

1. "Entrez Gene: adaptor-related protein complex 4".
2. Abou Jamra R, Philippe O, Raas-Rothschild A, Eck SH, Graf E, Buchert R, Borck G, Ekici A, Brockschmidt FF, Nöthen MM, Munnich A, Strom TM, Reis A, Colleaux L (May 2011). "Adaptor Protein Complex 4 Deficiency Causes Severe Autosomal-Recessive Intellectual Disability, Progressive Spastic Paraplegia, Shy Character, and Short Stature". Am J Hum Genet 88 (6): 788–95. doi:10.1016/j.ajhg.2011.04.019. PMC 3113253. PMID 21620353.

Further reading

• Dell'Angelica EC, Mullins C, Bonifacino JS (1999). "AP-4, a novel protein complex related to clathrin adaptors.". J. Biol. Chem. 274 (11): 7278–85. doi:10.1074/jbc.274.11.7278. PMID 10066790.
• Hirst J, Bright NA, Rous B, Robinson MS (1999). "Characterization of a fourth adaptor-related protein complex.". Mol. Biol. Cell 10 (8): 2787–802. doi:10.1091/mbc.10.8.2787. PMC 25515. PMID 10436028.