PC4 & SFRS1-interacting protein; CLL-associated antigen KW-7; dense fine speckles 70 kD protein; DFS 70; Lens epithelium-derived growth factor; transcriptional coactivator p75/p52 (PSIP1, DFS70, LEDGF, PSIP2)

Function

• transcriptional coactivator
• neuroepithelial stem cell differentiation & neurogenesis
• lens epithelial cell gene regulation & stress responses
• role in lens epithelial to fiber cell terminal differentiation
• protective role during stress-induced apoptosis (putative)
• interacts with IFRD1
• isoform 1
  • interacts POGZ & CDCA7L
  • interacts with lentiviral & HIV-1 integrase & acts as a chromatin tethering factor to the chromosomal DNA
  • interacts also with HIV-2 integrase
• isoform 2
  • more general & stronger transcriptional coactivator.
  • may also act as an adapter to coordinate pre-mRNA splicing
  • interacts with SFRS1
• cellular cofactor for lentiviral integration
• phosphorylated upon DNA damage, probably by ATM or ATR
• interacts with IFRD1/PC4

Structure

• monomer
• residues 340-417 are necessary & sufficient for the interaction with HIV-1 IN (IBD domain)
• belongs to the HDGF family
• contains 1 PWWP domain

Compartment

• nucleus
• chromatin-associated throughout the cell cycle

Alternative splicing

named isoforms=2

Expression

• widely expressed
• expressed in neurons, but not astrocytes
• elevated in fetal compared to adult brain
• in the adult brain, expressed in the subventricular zone, hippocampus, & undetectable elsewhere

Pathology

• chromosomal translocation t(9;11)(p22;p15) involving PSIP1 with NUP98 is associated with childhood acute myeloid leukemia

More general terms

• transcriptional adaptor protein; transcriptional coactivator
• phosphoprotein

Database

• Entrez gene: http://www.ncbi.nlm.nih.gov/sites/entrez?db=gene&cmd=Retrieve&dopt=Graphics&list_uids=11168
• Kegg: http://www.genome.jp/dbget-bin/www_bget?hsa:11168
• OMIM: https://mirror.omim.org/entry/603620
• UniProt: http://www.uniprot.org/uniprot/O75475.html