Reviewed, UniProtKB/Swiss-Prot P56377 (AP1S2_HUMAN)

Names and origin

Protein names

Recommended name:
    AP-1 complex subunit sigma-2
Alternative name(s):
    Adapter-related protein complex 1 sigma-1B subunit
    Adaptor protein complex AP-1 sigma-1B subunit
    Sigma-adaptin 1B
    Sigma1B-adaptin
    Golgi adaptor HA1/AP1 adaptin sigma-1B subunit
    Clathrin assembly protein complex 1 sigma-1B small chain
    Sigma 1B subunit of AP-1 clathrin

Gene names

Name:	AP1S2
ORF Names:	DC22

Organism

Homo sapiens (Human)

Taxonomic identifier

9606 [NCBI]

Taxonomic lineage

Eukaryota › Metazoa › Chordata › Craniata › Vertebrata › Euteleostomi › Mammalia › Eutheria › Euarchontoglires › Primates › Haplorrhini › Catarrhini › Hominidae › Homo

Protein attributes

Sequence length	157 AA.
Sequence status	Complete.
Sequence processing	The displayed sequence is not processed.
Protein existence	Evidence at protein level.

General annotation (Comments)

Function	Subunit of clathrin-associated adaptor protein complex 1 that plays a role in protein sorting in the late-Golgi/trans-Golgi network (TGN) and/or endosomes. The AP complexes mediate both the recruitment of clathrin to membranes and the recognition of sorting signals within the cytosolic tails of transmembrane cargo molecules.
Subunit structure	Adaptor protein complex 1 (AP-1) is an heterotetramer composed of two large adaptins (gamma-type subunit AP1G1 and beta-type subunit AP1B1), a medium adaptin (mu-type subunit AP1M1 or AP1M2) and a small adaptin (sigma-type subunit AP1S1 or AP1S2 or AP1S3). Binds to MUC1.
Subcellular location	Golgi apparatus. Cytoplasmic vesicle membrane; Peripheral membrane protein; Cytoplasmic side. Membrane › clathrin-coated pit. Note= Component of the coat surrounding the cytoplasmic face of coated vesicles located at the Golgi complex.
Tissue specificity	Widely expressed.
Involvement in disease	Defects in AP1S2 are the cause of X-linked mental retardation 59 (MRX59) [MIM:300630]. Mental retardation has a prevalence of about 2%-3% in developed populations and is more common in males than in females. Mutations in genes on the X chromosome are known to be a major cause of familial X-linked mental retardation. MRX59 consists of a mild-to-profound mental retardation. Other features includes hypotonia early in life and delay in walking.
Sequence similarities	Belongs to the adaptor complexes small subunit family.

Ontologies

Keywords
Biological process	Endocytosis Protein transport Transport
Cellular component	Coated pit Cytoplasmic vesicle Golgi apparatus Membrane
Disease	Mental retardation
Gene Ontology (GO)
Cellular component	AP-type membrane coat adaptor complex Ref.1 Traceable author statement. Source: ProtInc cytosol Inferred from Experiment. Source: Reactome
Complete GO annotation...

Sequence annotation (Features)

	Feature key	Position(s)	Length	Description	Graphical view
Molecule processing
	Chain	1 – 157	157	AP-1 complex subunit sigma-2
Experimental info
	Sequence conflict	1	1	M → L in AAG44595. Ref.2
	Sequence conflict	72 – 74	3	DQD → ESRN in AAC72946. Ref.5
	Sequence conflict	96 – 98	3	SVC → QCL Ref.5
	Sequence conflict	143	1	E → EE in AAG44595. Ref.2

Sequences

	Sequence		Length	Mass (Da)
	P56377-1 [UniParc]. Last modified July 15, 1998. Version 1. Checksum: DD9F59119909D89C	FASTA	157	18,615
	10 20 30 40 50 60 MQFMLLFSRQ GKLRLQKWYV PLSDKEKKKI TRELVQTVLA RKPKMCSFLE WRDLKIVYKR 70 80 90 100 110 120 YASLYFCCAI EDQDNELITL EIIHRYVELL DKYFGSVCEL DIIFNFEKAY FILDEFLLGG 130 140 150 EVQETSKKNV LKAIEQADLL QEEAETPRSV LEEIGLT

References

	« Hide 'large scale' referencesShow 'large scale' references »
[1]	"Identification and characterization of novel clathrin adaptor-related proteins." Takatsu H., Sakurai M., Shin H.-W., Murakami K., Nakayama K. J. Biol. Chem. 273:24693-24700(1998) [PubMed: 9733768] [Abstract] Cited for: NUCLEOTIDE SEQUENCE [MRNA].
[2]	"Novel genes expressed in human dendritic cell." Xu X., Yang Y., Gao G., Xiao H., Chen Z., Han Z. Submitted (MAY-2000) to the EMBL/GenBank/DDBJ databases Cited for: NUCLEOTIDE SEQUENCE [LARGE SCALE MRNA]. Tissue: Dendritic cell.
[3]	"Cloning of human full-length CDSs in BD Creator(TM) system donor vector." Kalnine N., Chen X., Rolfs A., Halleck A., Hines L., Eisenstein S., Koundinya M., Raphael J., Moreira D., Kelley T., LaBaer J., Lin Y., Phelan M., Farmer A. Submitted (MAY-2003) to the EMBL/GenBank/DDBJ databases Cited for: NUCLEOTIDE SEQUENCE [LARGE SCALE MRNA].
[4]	"The status, quality, and expansion of the NIH full-length cDNA project: the Mammalian Gene Collection (MGC)." The MGC Project Team Genome Res. 14:2121-2127(2004) [PubMed: 15489334] [Abstract] Cited for: NUCLEOTIDE SEQUENCE [LARGE SCALE MRNA]. Tissue: Skin and Uterus.
[5]	"Full-insert sequence of mapped XREF EST." Barrow I.K.-P., Boguski M.S., Touchman J.W., Spencer F. Submitted (AUG-1998) to the EMBL/GenBank/DDBJ databases Cited for: NUCLEOTIDE SEQUENCE [LARGE SCALE MRNA] OF 1-98.
[6]	"MUC1 membrane trafficking is modulated by multiple interactions." Kinlough C.L., Poland P.A., Bruns J.B., Harkleroad K.L., Hughey R.P. J. Biol. Chem. 279:53071-53077(2004) [PubMed: 15471854] [Abstract] Cited for: INTERACTION WITH MUC1.
[7]	"Mutations in the gene encoding the sigma 2 subunit of the adaptor protein 1 complex, AP1S2, cause X-linked mental retardation." Tarpey P.S., Stevens C., Teague J., Edkins S., O'Meara S., Avis T., Barthorpe S., Buck G., Butler A., Cole J., Dicks E., Gray K., Halliday K., Harrison R., Hills K., Hinton J., Jones D., Menzies A. , Mironenko T., Perry J., Raine K., Richardson D., Shepherd R., Small A., Tofts C., Varian J., West S., Widaa S., Yates A., Catford R., Butler J., Mallya U., Moon J., Luo Y., Dorkins H., Thompson D., Easton D.F., Wooster R., Bobrow M., Carpenter N., Simensen R.J., Schwartz C.E., Stevenson R.E., Turner G., Partington M., Gecz J., Stratton M.R., Futreal P.A., Raymond F.L. Am. J. Hum. Genet. 79:1119-1124(2006) [PubMed: 17186471] [Abstract] Cited for: INVOLVEMENT IN MRX59.
+	Additional computationally mapped references.

Cross-references

Sequence databases
EMBLGenBankDDBJ	AB015320 mRNA. Translation: BAA33392.1. AF251295 mRNA. Translation: AAG44595.1. Different initiation. BT006738 mRNA. Translation: AAP35384.1. BC001117 mRNA. Translation: AAH01117.1. BC071867 mRNA. Translation: AAH71867.1. AF091077 mRNA. Translation: AAC72946.1.
RefSeq	NP_003907.3.
UniGene	Hs.653504 Hs.656471
3D structure databases
HSSP	HSSP built from PDB template 1GW5 based on UniProtKB Q00380.
ModBase	Search...
Genome annotation databases
Ensembl	ENSG00000182287. Homo sapiens. [Contig view]
GeneID	8905.
KEGG	hsa:8905.
Organism-specific databases
H-InvDB	HIX0016674. HIX0039592.
HGNC	HGNC:560. AP1S2.
MIM	300629. gene. 300630. phenotype.
Orphanet	85335. Fried syndrome.
PharmGKB	PA24851.
GenAtlas	Search...
GeneCards	Search...
Phylogenomic databases
HOVERGEN	P56377.
Enzyme and pathway databases
Reactome	REACT_6185. HIV Infection.
Gene expression databases
ArrayExpress	P56377.
CleanEx	HS_AP1S2.
GermOnline	ENSG00000182287. Homo sapiens.
Family and domain databases
InterPro	IPR016635. AP_complex_ssu. IPR015604. Clathrin_AP1_sigma. IPR000804. Clathrin_sigma/coatomer_zeta. [Graphical view]
PANTHER	PTHR11753:SF5. Clathrin_coat_assembly_AP19. 1 hit.
Pfam	PF01217. Clat_adaptor_s. 1 hit. [Graphical view]
PIRSF	PIRSF015588. AP_complex_sigma. 1 hit.
PROSITE	PS00989. CLAT_ADAPTOR_S. 1 hit. [Graphical view]
ProDom	P56377. [Graphical view] [Entries sharing at least one domain]
BLOCKS	Search...
Other Resources
LinkHub	P56377.
SOURCE	Search...
ProtoNet	Search...

Entry information

Entry name

AP1S2_HUMAN

Accession

Primary (citable) accession number: P56377
Secondary accession number(s): O95326, Q9H2N6

Entry history

Integrated into UniProtKB/Swiss-Prot:	July 15, 1998
Last sequence update:	July 15, 1998
Last modified:	July 22, 2008
This is version 79 of the entry and version 1 of the sequence. [Complete history]

Entry status

Reviewed (UniProtKB/Swiss-Prot)

Annotation project

HPI (Human Proteome Initiative)