activated RNA polymerase 2 transcriptional coactivator p15; positive cofactor 4; activated RNA polymerase 2 transcription cofactor 4 (SUB1, PC4, RPO2TC1, p14)

Function

• general coactivator
• functions cooperatively with TAFs & mediates functional interactions between upstream activators & the general transcriptional machinery
• may be involved in stabilizing the multiprotein transcription complex
• binds single-stranded DNA
• also binds, in vitro, non-specifically to double-stranded DNA (ds DNA)
• activity is controlled by protein kinases that target the regulatory region
• phosphorylation inactivates both ds DNA-binding & cofactor function, but does not affect binding to ssDNA
• seems to be phosphorylated in vivo by CK2 in at least 7 sites in the N-terminal Ser-rich region
• interacts with CSTF2

Structure

• homodimer
• belongs to the transcriptional coactivator PC4 family
• mass spec: mass=14266; mass_error=4; method=MALDI mass spec: mass=14263; method=electrospray

Compartment

nucleus

More general terms

• nuclear protein
• phosphoprotein

Database

• Kegg: http://www.genome.jp/dbget-bin/www_bget?hsa:1092
• OMIM: https://mirror.omim.org/entry/600503
• UniProt: http://www.uniprot.org/uniprot/P53999.html
• Entrez gene: http://www.ncbi.nlm.nih.gov/sites/entrez?db=gene&cmd=Retrieve&dopt=Graphics&list_uids=10923