ubiquitin carboxyl-terminal hydrolase 22; deubiquitinating enzyme 22; ubiquitin thiolesterase 22; ubiquitin-specific-processing protease 22 (USP22, KIAA1063)

Function

• histone deubiquitinating component of the transcription regulatory histone acetylation (HAT) complex SAGA
• catalyzes deubiquitination of both histones H2A & H2B, thereby acting as a coactivator
• recruited to specific gene promoters by activators such as MYC, where it is required for transcription
• required for nuclear receptor-mediated transactivation & cell cycle progression
• thiol-dependent hydrolysis of ester, thioester, amide, peptide & isopeptide bonds formed by the C-terminal Gly of ubiquitin
• component of SAGA transcription coactivator-HAT complex
• within the SAGA complex, ATXN7L3, ENY2 & USP22 form a subcomplex required for histone deubiquitinylation
• interacts directly with ATXN7L3; leading to its recruitment to the SAGA complex

Structure

• belongs to the peptidase C19 family, UBP8 subfamily
• contains 1 UBP-type Zn+2 finger

Compartment

nucleus (probable)

Alternative splicing

named isoforms=2

Expression

• moderately expressed in heart & skeletal muscle,
• weakly expressed in lung & liver

More general terms

• ubiquitin C-terminal hydrolase
• nuclear protein
• zinc finger protein

Additional terms

• ubiquitin (UBCEP2, UBB, UBC)

Component of

• histone acetylation (HAT) complex SAGA

Database

• Entrez gene: http://www.ncbi.nlm.nih.gov/sites/entrez?db=gene&cmd=Retrieve&dopt=Graphics&list_uids=23326
• Kegg: http://www.genome.jp/dbget-bin/www_bget?hsa:23326
• UniProt: http://www.uniprot.org/uniprot/Q9UPT9.html