ubiquitin carboxyl-terminal hydrolase 21; deubiquitinating enzyme 21; ubiquitin thiolesterase 21; ubiquitin-specific-processing protease 21 (USP21, PP1490)

Function

• deubiquitinates histone H2A, a specific tag for epigenetic transcriptional repression, thereby acting as a coactivator
• deubiquitination of histone H2A releaves the repression of di- & trimethylation of histone H3 at Lys-4, resulting in regulation of transcriptional initiation
• regulates gene expression via histone H2A deubiquitination (putative)
• also capable of removing NEDD8 from NEDD8 conjugates but has no effect on sentrin-1 conjugates
• thiol-dependent hydrolysis of ester, thioester, amide, peptide & isopeptide bonds formed by the C-terminal Gly of ubiquitin

Structure

• belongs to the peptidase C19 family, USP21 subfamily

Compartment

nucleus (putative)

Alternative splicing

named isoforms=3

Expression

• highly expressed in heart, pancreas & skeletal muscle
• also expressed in brain, placenta, liver & kidney
• expressed at very low level in lung

More general terms

• ubiquitin C-terminal hydrolase
• nuclear protein

Additional terms

• ubiquitin (UBCEP2, UBB, UBC)

Database

• Entrez gene: http://www.ncbi.nlm.nih.gov/sites/entrez?db=gene&cmd=Retrieve&dopt=Graphics&list_uids=27005
• Kegg: http://www.genome.jp/dbget-bin/www_bget?hsa:27005
• OMIM: https://mirror.omim.org/entry/604729
• UniProt: http://www.uniprot.org/uniprot/Q9UK80.html