proteasome assembly chaperone 1; PAC-1; chromosome 21 leucine-rich protein; C21-LRP; Down syndrome critical region protein 2 (PSMG1, C21LRP, DSCR2, PAC1)

Function

• chaperone protein that promotes assembly of the 20S proteasome as part of a heterodimer with PSMG2
• the PSMG1-PSMG2 heterodimer binds to the PSMA5 & PSMA7 proteasome subunits
• promotes assembly of the proteasome alpha subunits into the heteroheptameric alpha ring & prevents alpha ring dimerization
• degraded by the proteasome upon completion of 20S proteasome maturation
• forms a heterodimer with PSMG2
• the PSMG1-PSMG2 heterodimer interacts directly with the PSMA5 & PSMA7 proteasome alpha subunits

Structure

belongs to the PSMG1 family

Compartment

cytoplasm, endoplasmic reticulum

Alternative splicing

named isoforms=2

Expression

• in the adult, detected in brain, colon, leukocytes, breast & testis
• widely expressed in the fetus
• expressed in a variety of proliferating cell lines

More general terms

• Down syndrome critical region protein
• phosphoprotein

Database

• Entrez gene: http://www.ncbi.nlm.nih.gov/sites/entrez?db=gene&cmd=Retrieve&dopt=Graphics&list_uids=8624
• Kegg: http://www.genome.jp/dbget-bin/www_bget?hsa:8624
• OMIM: https://mirror.omim.org/entry/605296
• UniProt: http://www.uniprot.org/uniprot/O95456.html