baculoviral IAP repeat-containing protein 5; apoptosis inhibitor survivin; apoptosis inhibitor 4 (BIRC5, API4, IAP4)

Function

• peptide inhibitor of apoptosis
• may counteract a default induction of apoptosis in G2/M phase
• interacts with tubulin inhibitor of caspase-3 & caspase-7
• component of the chromosomal passenger complex
• isoforms 2 & 3 do not appear to play vital roles in mitosis
• isoform 3 shows a marked reduction in its anti-apoptotic effects when compared with the displayed wild-type isoform
• when phosphorylated, interacts with HBXIP; the resulting complex binds pro-caspase-9, as well as active caspase-9, but much less efficiently
• interacts with EVI5

Structure

• homodimer
• the BIR repeat is necessary & sufficient for HBXIP binding
• belongs to the IAP family
• contains 1 BIR repeat

Compartment

• cytoplasm, nucleus, centromere
• localizes on chromosome arms & inner centromeres from prophase through metaphase & then transferring to the spindle midzone & midbody from anaphase through cytokinesis
• colocalizes with AURKB at mitotic chromosomes

Alternative splicing

named isoforms=7

Expression

• expressed only in fetal kidney & liver, & to lesser extent, lung & brain

Pathology

• BIRC5 may play a role in neoplasia
• identified in several human cancers
• overproduction may foster survival of neoplastic cells otherwise programmed or targeted for apoptosis
• abundantly expressed in adenocarcinomas
  • lung adenocarcinoma
  • pancreatic carcinoma
  • colorectal carcinoma
  • breast carcinoma
  • prostate carcinoma
• also abundantly expressed in high-grade lymphomas
• also expressed in various renal cell carcinoma cell lines

Laboratory

• urinary survivin (or survivin mRNA) measurements may be useful for identifying new-onset or recurrent bladder cancer

More general terms

• inhibitor of apoptosis protein
• phosphoprotein

Database

• Entrez gene: http://www.ncbi.nlm.nih.gov/sites/entrez?db=gene&cmd=Retrieve&dopt=Graphics&list_uids=332
• Kegg: http://www.genome.jp/dbget-bin/www_bget?hsa:332
• OMIM: https://mirror.omim.org/entry/603352
• UniProt: http://www.uniprot.org/uniprot/O15392.html