Reviewed, UniProtKB/Swiss-Prot P53680 (AP2S1_HUMAN)

Names and origin

Protein names

Recommended name:
    AP-2 complex subunit sigma
Alternative name(s):
    Adapter-related protein complex 2 sigma subunit
    Adaptor protein complex AP-2 subunit sigma
    Sigma2-adaptin
    Plasma membrane adaptor AP-2 17 kDa protein
    HA2 17 kDa subunit
    Clathrin assembly protein 2 small chain
    Clathrin coat assembly protein AP17
    Clathrin coat-associated protein AP17

Gene names

Name:	AP2S1
Synonyms:	AP17, CLAPS2

Organism

Homo sapiens (Human) [Complete proteome]

Taxonomic identifier

9606 [NCBI]

Taxonomic lineage

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

Protein attributes

Sequence length	142 AA.
Sequence status	Complete.
Sequence processing	The displayed sequence is not processed.
Protein existence	Evidence at protein level.

General annotation (Comments)

Function	Component of the adaptor protein complex 2 (AP-2). Adaptor protein complexes function in protein Transport via Transport vesicles in different membrane traffic pathways. Adaptor protein complexes are vesicle coat components and appear to be involved in cargo selection and vesicle formation. AP-2 is involved in clathrin-dependent endocytosis in which cargo proteins are incorporated into vesicles surrrounded by clathrin (clathrin-coated vesicles, CCVs) which are destined for fusion with the early endosome. The clathrin lattice serves as a mechanical scaffold but is itself unable to bind directly to membrane components. Clathrin-associated adaptor protein (AP) complexes which can bind directly to both the clathrin lattice and to the lipid and protein components of membranes are considered to be the major clathrin adaptors contributing the CCV formation. AP-2 also serves as a cargo receptor to selectively sort the membrane proteins involved in receptor-mediated endocytosis. AP-2 seems to play a role in the recycling of synaptic vesicle membranes from the presynaptic surface. AP-2 recognizes Y-X-X-[FILMV] (Y-X-X-Phi) and [ED]-X-X-X-L-[LI] endocytosis signal motifs within the cytosolic tails of transmembrane cargo molecules. AP-2 may also play a role in maintaining normal post-endocytic trafficking through the ARF6-regulated, non-clathrin pathway. The AP-2 alpha and AP-2 sigma subunits are thought to contribute to the recognition of the [ED]-X-X-X-L-[LI] motif By similarity.
Subunit structure	Adaptor protein complex 2 (AP-2) is an heterotetramer composed of two large adaptins (alpha-type subunit AP2A1 or AP2A2 and beta-type subunit AP2B1), a medium adaptin (mu-type subunit AP2M1) and a small adaptin (sigma-type subunit AP2S1).
Subcellular location	Cell membrane. Membrane › coated pit; Peripheral membrane protein; Cytoplasmic side. Note: AP-2 appears to be excluded from internalizing CCVs and to disengage from sites of endocytosis seconds before internalization of the nascent CCV By similarity.
Sequence similarities	Belongs to the adaptor complexes small subunit family.

Ontologies

Keywords
Biological process	Protein transport Transport
Cellular component	Cell membrane Coated pit Membrane
Coding sequence diversity	Alternative splicing
PTM	Phosphoprotein
Technical term	Complete proteome
Gene Ontology (GO)
Biological process	clathrin coat assembly Traceable author statement. Source: UniProtKB intracellular protein transport Inferred from electronic annotation. Source: InterPro regulation of defense response to virus by virus Inferred from Experiment. Source: Reactome regulation of endocytosis Traceable author statement. Source: UniProtKB
Cellular component	AP-2 adaptor complex Traceable author statement. Source: UniProtKB cytosol Inferred from Experiment. Source: Reactome
Molecular function	protein binding Inferred from electronic annotation. Source: InterPro protein transporter activity Non-traceable author statement. Source: UniProtKB
Complete GO annotation...

Alternative products

This entry describes 2 isoforms produced by alternative splicing. [Align] [Select]

Isoform 1 (identifier: P53680-1)

This isoform has been chosen as the 'canonical' sequence. All positional information in this entry refers to it. This is also the sequence that appears in the downloadable versions of the entry.

Isoform 2 (identifier: P53680-2)

The sequence of this isoform differs from the canonical sequence as follows:
     52-89: Missing.

Sequence annotation (Features)

	Feature key	Position(s)	Length	Description	Graphical view	Feature identifier
Molecule processing
	Chain	1 – 142	142	AP-2 complex subunit sigma		PRO_0000193804
Amino acid modifications
	Modified residue	140	1	Phosphoserine Ref.9
Natural variations
	Alternative sequence	52 – 89	38	Missing in isoform 2.		VSP_017352
Experimental info
	Sequence conflict	77	1	N → K in CAA65782. Ref.1
	Sequence conflict	77	1	N → K in CAA09018. Ref.2
	Sequence conflict	83	1	A → G in CAA65782. Ref.1
	Sequence conflict	83	1	A → G in CAA09018. Ref.2

Sequences

	Sequence		Length	Mass (Da)
	Isoform 1 [UniParc]. Last modified August 16, 2004. Version 2. Checksum: CA3FD868C65AEDF6	FASTA	142	17,018
	10 20 30 40 50 60 MIRFILIQNR AGKTRLAKWY MQFDDDEKQK LIEEVHAVVT VRDAKHTNFV EFRNFKIIYR 70 80 90 100 110 120 RYAGLYFCIC VDVNDNNLAY LEAIHNFVEV LNEYFHNVCE LDLVFNFYKV YTVVDEMFLA 130 140 GEIRETSQTK VLKQLLMLQS LE
	Isoform 2. Checksum: 0240F8D55B64095C	FASTA	104	12,417
	10 20 30 40 50 60 MIRFILIQNR AGKTRLAKWY MQFDDDEKQK LIEEVHAVVT VRDAKHTNFV EVLNEYFHNV 70 80 90 100 CELDLVFNFY KVYTVVDEMF LAGEIRETSQ TKVLKQLLML QSLE

References

	« Hide 'large scale' referencesShow 'large scale' references »
[1]	"Human CLAPS2 encoding AP17, a small chain of the clathrin-associated protein complex: cDNA cloning and chromosomal assignment to 19q13.2-->q13.3." Winterpacht A., Endele S., Enklaar T., Fuhry M., Zabel B. Cytogenet. Cell Genet. 75:132-135(1996) [PubMed: 9040778] [Abstract] Cited for: NUCLEOTIDE SEQUENCE [MRNA] (ISOFORM 1). Tissue: Kidney.
[2]	"A novel spliced transcript of human CLAPS2 encoding a protein alternative to clathrin adaptor protein AP17." Holzmann K., Poeltl A., Sauermann G. Gene 220:39-44(1998) [PubMed: 9767099] [Abstract] Cited for: NUCLEOTIDE SEQUENCE [MRNA] (ISOFORMS 1 AND 2).
[3]	"Complete sequencing and characterization of 21,243 full-length human cDNAs." Ota T., Suzuki Y., Nishikawa T., Otsuki T., Sugiyama T., Irie R., Wakamatsu A., Hayashi K., Sato H., Nagai K., Kimura K., Makita H., Sekine M., Obayashi M., Nishi T., Shibahara T., Tanaka T., Ishii S. , Yamamoto J., Saito K., Kawai Y., Isono Y., Nakamura Y., Nagahari K., Murakami K., Yasuda T., Iwayanagi T., Wagatsuma M., Shiratori A., Sudo H., Hosoiri T., Kaku Y., Kodaira H., Kondo H., Sugawara M., Takahashi M., Kanda K., Yokoi T., Furuya T., Kikkawa E., Omura Y., Abe K., Kamihara K., Katsuta N., Sato K., Tanikawa M., Yamazaki M., Ninomiya K., Ishibashi T., Yamashita H., Murakawa K., Fujimori K., Tanai H., Kimata M., Watanabe M., Hiraoka S., Chiba Y., Ishida S., Ono Y., Takiguchi S., Watanabe S., Yosida M., Hotuta T., Kusano J., Kanehori K., Takahashi-Fujii A., Hara H., Tanase T.-O., Nomura Y., Togiya S., Komai F., Hara R., Takeuchi K., Arita M., Imose N., Musashino K., Yuuki H., Oshima A., Sasaki N., Aotsuka S., Yoshikawa Y., Matsunawa H., Ichihara T., Shiohata N., Sano S., Moriya S., Momiyama H., Satoh N., Takami S., Terashima Y., Suzuki O., Nakagawa S., Senoh A., Mizoguchi H., Goto Y., Shimizu F., Wakebe H., Hishigaki H., Watanabe T., Sugiyama A., Takemoto M., Kawakami B., Yamazaki M., Watanabe K., Kumagai A., Itakura S., Fukuzumi Y., Fujimori Y., Komiyama M., Tashiro H., Tanigami A., Fujiwara T., Ono T., Yamada K., Fujii Y., Ozaki K., Hirao M., Ohmori Y., Kawabata A., Hikiji T., Kobatake N., Inagaki H., Ikema Y., Okamoto S., Okitani R., Kawakami T., Noguchi S., Itoh T., Shigeta K., Senba T., Matsumura K., Nakajima Y., Mizuno T., Morinaga M., Sasaki M., Togashi T., Oyama M., Hata H., Watanabe M., Komatsu T., Mizushima-Sugano J., Satoh T., Shirai Y., Takahashi Y., Nakagawa K., Okumura K., Nagase T., Nomura N., Kikuchi H., Masuho Y., Yamashita R., Nakai K., Yada T., Nakamura Y., Ohara O., Isogai T., Sugano S. Nat. Genet. 36:40-45(2004) [PubMed: 14702039] [Abstract] Cited for: NUCLEOTIDE SEQUENCE [LARGE SCALE MRNA] (ISOFORM 1). Tissue: Tongue.
[4]	Mural R.J., Istrail S., Sutton G.G., Florea L., Halpern A.L., Mobarry C.M., Lippert R., Walenz B., Shatkay H., Dew I., Miller J.R., Flanigan M.J., Edwards N.J., Bolanos R., Fasulo D., Halldorsson B.V., Hannenhalli S., Turner R. , Yooseph S., Lu F., Nusskern D.R., Shue B.C., Zheng X.H., Zhong F., Delcher A.L., Huson D.H., Kravitz S.A., Mouchard L., Reinert K., Remington K.A., Clark A.G., Waterman M.S., Eichler E.E., Adams M.D., Hunkapiller M.W., Myers E.W., Venter J.C. Submitted (JUL-2005) to the EMBL/GenBank/DDBJ databases Cited for: NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA].
[5]	"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] (ISOFORM 1). Tissue: Uterus.
[6]	"Adaptor protein complexes as the key regulators of protein sorting in the post-Golgi network." Nakatsu F., Ohno H. Cell Struct. Funct. 28:419-429(2003) [PubMed: 14745134] [Abstract] Cited for: FUNCTION OF THE AP-2 COMPLEX IN CLATHRIN-MEDIATED ENDOCYTOSIS.
[7]	"Adaptors for clathrin coats: structure and function." Owen D.J., Collins B.M., Evans P.R. Annu. Rev. Cell Dev. Biol. 20:153-191(2004) [PubMed: 15473838] [Abstract] Cited for: FUNCTION OF THE AP-2 COMPLEX IN CLATHRIN-MEDIATED ENDOCYTOSIS.
[8]	"The adaptor complex AP-2 regulates post-endocytic trafficking through the non-clathrin Arf6-dependent endocytic pathway." Lau A.W., Chou M.M. J. Cell Sci. 121:4008-4017(2008) [PubMed: 19033387] [Abstract] Cited for: FUNCTION OF THE AP-2 COMPLEX IN NON-CLATHRIN-DEPENDENT ENDOCYTOSIS.
[9]	"Kinase-selective enrichment enables quantitative phosphoproteomics of the kinome across the cell cycle." Daub H., Olsen J.V., Bairlein M., Gnad F., Oppermann F.S., Korner R., Greff Z., Keri G., Stemmann O., Mann M. Mol. Cell 31:438-448(2008) [PubMed: 18691976] [Abstract] Cited for: PHOSPHORYLATION [LARGE SCALE ANALYSIS] AT SER-140, MASS SPECTROMETRY.
[10]	Colinge J., Superti-Furga G., Bennett K.L. Submitted (OCT-2008) to UniProtKB Cited for: IDENTIFICATION [LARGE SCALE ANALYSIS], MASS SPECTROMETRY.
+	Additional computationally mapped references.

Cross-references

Sequence databases
EMBLGenBankDDBJ	X97074 mRNA. Translation: CAA65782.1. AJ010148 mRNA. Translation: CAA09018.1. AJ010149 mRNA. Translation: CAA09019.1. AK312003 mRNA. Translation: BAG34941.1. CH471126 Genomic DNA. Translation: EAW57448.1. BC006337 mRNA. Translation: AAH06337.1.
IPI	IPI00183781. IPI00219840.
RefSeq	NP_004060.2. NP_067586.1.
UniGene	Hs.119591
3D structure databases
SMR	P53680. Positions 1-142.
ModBase	Search...
Protein-protein interaction databases
STRING	P53680.
PTM databases
PhosphoSite	P53680.
Proteomic databases
PRIDE	P53680.
Genome annotation databases
Ensembl	ENST00000263270; ENSP00000263270; ENSG00000042753; Homo sapiens. [Genome view]
GeneID	1175.
KEGG	hsa:1175.
UCSC	uc002pft.1. human. uc002pfu.1. human.
Organism-specific databases
CTD	1175.
GeneCards	GC19M052033.
H-InvDB	HIX0015263.
HGNC	HGNC:565. AP2S1.
MIM	602242. gene.
PharmGKB	PA24856.
GenAtlas	Search...
Phylogenomic databases
HOGENOM	HBG333059.
HOVERGEN	P53680.
InParanoid	P53680.
OMA	HRLVAPR.
Enzyme and pathway databases
Reactome	REACT_13685. Synaptic Transmission. REACT_6185. HIV Infection.
Gene expression databases
ArrayExpress	P53680.
Bgee	P53680.
CleanEx	HS_AP2S1.
Genevestigator	P53680.
GermOnline	ENSG00000042753. Homo sapiens.
Family and domain databases
InterPro	IPR016635. AP_complex_ssu. IPR000804. Clathrin_sigma/coatomer_zeta. IPR011012. Longin-like. [Graphical view]
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]
ProtoNet	Search...
Other Resources
NextBio	4856.
SOURCE	Search...

Entry information

Entry name

AP2S1_HUMAN

Accession

Primary (citable) accession number: P53680
Secondary accession number(s): B2R4Z4, O75977, Q6PK67

Entry history

Integrated into UniProtKB/Swiss-Prot:	October 1, 1996
Last sequence update:	August 16, 2004
Last modified:	December 15, 2009
This is version 78 of the entry and version 2 of the sequence. [Complete history]

Entry status

Reviewed (UniProtKB/Swiss-Prot)

Annotation project

HPI (Human Proteome Initiative)

Disclaimer

Any medical or genetic information present in this entry is provided for research, educational and informational purposes only. It is not in any way intended to be used as a substitute for professional medical advice, diagnosis, treatment or care.