PSME2 (proteasome activator subunit 2)

Gene

• Entrez ID: 5721
• Gene name: Proteasome activator subunit 2
• Gene symbol: PSME2
• Synonyms: PA28B, PA28beta, REGbeta
• Chromosome: 14
• Chromosome location: 14q12
• Summary: The 26S proteasome is a multicatalytic proteinase complex with a highly ordered structure composed of 2 complexes, a 20S core and a 19S regulator. The 20S core is composed of 4 rings of 28 non-identical subunits; 2 rings are composed of 7 alpha subunits and 2 rings are composed of 7 beta subunits. The 19S regulator is composed of a base, which contains 6 ATPase subunits and 2 non-ATPase subunits, and a lid, which contains up to 10 non-ATPase subunits. Proteasomes are distributed throughout eukaryotic cells at a high concentration and cleave peptides in an ATP/ubiquitin-dependent process in a non-lysosomal pathway. An essential function of a modified proteasome, the immunoproteasome, is the processing of class I MHC peptides. The immunoproteasome contains an alternate regulator, referred to as the 11S regulator or PA28, that replaces the 19S regulator. Three subunits (alpha, beta and gamma) of the 11S regulator have been identified. This gene encodes the beta subunit of the 11S regulator, one of the two 11S subunits that is induced by gamma-interferon. Three beta and three alpha subunits combine to form a heterohexameric ring. Six pseudogenes have been identified on chromosomes 4, 5, 8, 10 and 13. [provided by RefSeq, Jul 2008]

Gene ontology (GO)

GO ID	Ontology	Definition	Evidence	Reference
GO:0000165	Process	MAPK cascade	TAS
GO:0000209	Process	Protein polyubiquitination	TAS
GO:0000502	Component	Proteasome complex	TAS	8811196
GO:0002223	Process	Stimulatory C-type lectin receptor signaling pathway	TAS
GO:0002479	Process	Antigen processing and presentation of exogenous peptide antigen via MHC class I, TAP-dependent	TAS
GO:0005515	Function	Protein binding	IPI	16189514, 32296183
GO:0005654	Component	Nucleoplasm	IBA	21873635
GO:0005654	Component	Nucleoplasm	TAS
GO:0005737	Component	Cytoplasm	IBA	21873635
GO:0005829	Component	Cytosol	TAS
GO:0006521	Process	Regulation of cellular amino acid metabolic process	TAS
GO:0008537	Component	Proteasome activator complex	IEA
GO:0010950	Process	Positive regulation of endopeptidase activity	IBA	21873635
GO:0010972	Process	Negative regulation of G2/M transition of mitotic cell cycle	TAS
GO:0016020	Component	Membrane	HDA	19946888
GO:0016579	Process	Protein deubiquitination	TAS
GO:0031145	Process	Anaphase-promoting complex-dependent catabolic process	TAS
GO:0031146	Process	SCF-dependent proteasomal ubiquitin-dependent protein catabolic process	TAS
GO:0033209	Process	Tumor necrosis factor-mediated signaling pathway	TAS
GO:0035722	Process	Interleukin-12-mediated signaling pathway	TAS
GO:0038061	Process	NIK/NF-kappaB signaling	TAS
GO:0038095	Process	Fc-epsilon receptor signaling pathway	TAS
GO:0042802	Function	Identical protein binding	IPI	16189514, 32296183
GO:0043161	Process	Proteasome-mediated ubiquitin-dependent protein catabolic process	TAS
GO:0043488	Process	Regulation of mRNA stability	TAS
GO:0043687	Process	Post-translational protein modification	TAS
GO:0050852	Process	T cell receptor signaling pathway	TAS
GO:0055085	Process	Transmembrane transport	TAS
GO:0060071	Process	Wnt signaling pathway, planar cell polarity pathway	TAS
GO:0061133	Function	Endopeptidase activator activity	IBA	21873635
GO:0061136	Process	Regulation of proteasomal protein catabolic process	IBA	21873635
GO:0061418	Process	Regulation of transcription from RNA polymerase II promoter in response to hypoxia	TAS
GO:0070062	Component	Extracellular exosome	HDA	19056867, 23533145
GO:0070498	Process	Interleukin-1-mediated signaling pathway	TAS
GO:0090090	Process	Negative regulation of canonical Wnt signaling pathway	TAS
GO:0090263	Process	Positive regulation of canonical Wnt signaling pathway	TAS
GO:1901990	Process	Regulation of mitotic cell cycle phase transition	TAS
GO:1902036	Process	Regulation of hematopoietic stem cell differentiation	TAS
GO:2000045	Process	Regulation of G1/S transition of mitotic cell cycle	IBA	21873635

Other IDs

• MIM: 602161
• HGNC: 9569
• e!Ensembl: ENSG00000100911

Protein

• UniProt ID: Q9UL46
• Protein name: Proteasome activator complex subunit 2 (11S regulator complex subunit beta) (REG-beta) (Activator of multicatalytic protease subunit 2) (Proteasome activator 28 subunit beta) (PA28b) (PA28beta)
• Protein function: Implicated in immunoproteasome assembly and required for efficient antigen processing. The PA28 activator complex enhances the generation of class I binding peptides by altering the cleavage pattern of the proteasome.
• PDB: 7DR6, 7DRW
• Family and domains:

  Pfam

  Accession	ID	Position in sequence	Description	Type
  PF02251	PA28_alpha	11 → 71	Proteasome activator pa28 alpha subunit	Family
  PF02252	PA28_beta	93 → 237	Proteasome activator pa28 beta subunit	Family

• Sequence:

  MAKPCGVRLSGEARKQVEVFRQNLFQEAEEFLYRFLPQKIIYLNQLLQEDSLNVADLTSL
  RAPLDIPIPDPPPKDDEMETDKQEKKEVHKCGFLPGNEKVLSLLALVKPEVWTLKEKCIL
  VITWIQHLIPKIEDGNDFGVAIQEKVLERVNAVKTKVEAFQTTISKYFSERGDAVAKASK
  ETHVMDYRALVHERDEAAYGELRAMVLDLRAFYAELYHIISSNLEKIVNPKGEEKPSMY

• Sequence length: 239