PSMB8 (proteasome 20S subunit beta 8)

Gene

• Entrez ID: 5696
• Gene name: Proteasome 20S subunit beta 8
• Gene symbol: PSMB8
• Synonyms: ALDD, D6S216, D6S216E, JMP, LMP7, NKJO, PRAAS1, PSMB5i, RING10
• Chromosome: 6
• Chromosome location: 6p21.32
• Summary: The proteasome is a multicatalytic proteinase complex with a highly ordered ring-shaped 20S core structure. The core structure 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. 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. This gene encodes a member of the proteasome B-type family, also known as the T1B family, that is a 20S core beta subunit. This gene is located in the class II region of the MHC (major histocompatibility complex). Expression of this gene is induced by gamma interferon and this gene product replaces catalytic subunit 3 (proteasome beta 5 subunit) in the immunoproteasome. Proteolytic processing is required to generate a mature subunit. Two alternative transcripts encoding two isoforms have been identified; both isoforms are processed to yield the same mature subunit. [provided by RefSeq, Jul 2008]

SNPs

SNP ID	Visualize variation	Clinical significance	Consequence
rs387906680	C>A,T	Pathogenic	Missense variant, coding sequence variant

miRNA

miRTarBase ID	miRNA	Experiments	Reference
MIRT029309	hsa-miR-26b-5p	Microarray	19088304

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	IDA	26524591
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:0004175	Function	Endopeptidase activity	IBA	21873635
GO:0004298	Function	Threonine-type endopeptidase activity	IEA
GO:0005515	Function	Protein binding	IPI	15303969
GO:0005634	Component	Nucleus	IBA	21873635
GO:0005654	Component	Nucleoplasm	TAS
GO:0005737	Component	Cytoplasm	IBA	21873635
GO:0005829	Component	Cytosol	TAS
GO:0005839	Component	Proteasome core complex	IBA	21873635
GO:0005839	Component	Proteasome core complex	ISS
GO:0006521	Process	Regulation of cellular amino acid metabolic process	TAS
GO:0010499	Process	Proteasomal ubiquitin-independent protein catabolic process	IBA	21873635
GO:0010972	Process	Negative regulation of G2/M transition of mitotic cell cycle	TAS
GO:0016032	Process	Viral process	IEA
GO:0016579	Process	Protein deubiquitination	TAS
GO:0019774	Component	Proteasome core complex, beta-subunit complex	ISS
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:0038061	Process	NIK/NF-kappaB signaling	TAS
GO:0038095	Process	Fc-epsilon receptor signaling pathway	TAS
GO:0043161	Process	Proteasome-mediated ubiquitin-dependent protein catabolic process	IBA	21873635
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:0045444	Process	Fat cell differentiation	IMP	21881205
GO:0050852	Process	T cell receptor signaling pathway	TAS
GO:0052548	Process	Regulation of endopeptidase activity	IMP	26524591
GO:0055085	Process	Transmembrane transport	TAS
GO:0060071	Process	Wnt signaling pathway, planar cell polarity pathway	TAS
GO:0060337	Process	Type I interferon signaling pathway	TAS
GO:0061418	Process	Regulation of transcription from RNA polymerase II promoter in response to hypoxia	TAS
GO:0070062	Component	Extracellular exosome	HDA	20458337
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:1990111	Component	Spermatoproteasome complex	ISS

Other IDs

• MIM: 177046
• HGNC: 9545
• e!Ensembl: ENSG00000204264

Protein

• UniProt ID: P28062
• Protein name: Proteasome subunit beta type-8 (EC 3.4.25.1) (Low molecular mass protein 7) (Macropain subunit C13) (Multicatalytic endopeptidase complex subunit C13) (Proteasome component C13) (Proteasome subunit beta-5i) (Really interesting new gene 10 protein)
• Protein function: The proteasome is a multicatalytic proteinase complex which is characterized by its ability to cleave peptides with Arg, Phe, Tyr, Leu, and Glu adjacent to the leaving group at neutral or slightly basic pH. The proteasome has an ATP-dependent proteolytic activity. This subunit is involved in antigen processing to generate class I binding peptides. Replacement of PSMB5 by PSMB8 increases the capacity of the immunoproteasome to cleave model peptides after hydrophobic and basic residues. Involved in the generation of spliced peptides resulting from the ligation of two separate proteasomal cleavage products that are not contiguous in the parental protein (PubMed:27049119). Acts as a major component of interferon gamma-induced sensitivity. Plays a key role in apoptosis via the degradation of the apoptotic inhibitor MCL1. May be involved in the inflammatory response pathway. In cancer cells, substitution of isoform 1 (E2) by isoform 2 (E1) results in immunoproteasome deficiency. Required for the differentiation of preadipocytes into adipocytes.
• PDB: 5L5A, 5L5B, 5L5D, 5L5E, 5L5F, 5L5H, 5L5I, 5L5J, 5L5O, 5L5P, 5L5Q, 5L5R, 5L5S, 5L5T, 5L5U, 5L5V, 5LTT, 5M2B, 6AVO, 6E5B
• Family and domains:

  Pfam

  Accession	ID	Position in sequence	Description	Type
  PF00227	Proteasome	69 → 251	Proteasome subunit	Domain

• Sequence:

  MALLDVCGAPRGQRPESALPVAGSGRRSDPGHYSFSMRSPELALPRGMQPTEFFQSLGGD
  GERNVQIEMAHGTTTLAFKFQHGVIAAVDSRASAGSYISALRVNKVIEINPYLLGTMSGC
  AADCQYWERLLAKECRLYYLRNGERISVSAASKLLSNMMCQYRGMGLSMGSMICGWDKKG
  PGLYYVDEHGTRLSGNMFSTGSGNTYAYGVMDSGYRPNLSPEEAYDLGRRAIAYATHRDS
  YSGGVVNMYHMKEDGWVKVESTDVSDLLHQYREANQ

• Sequence length: 276