Seven In Absentia Homolog 1 (SIAH1)

SIAH1 is an E3 ligase and is involved in ubiquitination and proteasome-mediated degradation of specific proteins. The activity of this ubiquitin ligase has been implicated in the development of certain forms of Parkinson's disease, the regulation of the cellular response to hypoxia and induction of apoptosis. Alternative splicing results in several additional transcript variants, some encoding different isoforms and others that have not been fully characterized.The deduced 195-amino acid SIAH1S protein is identical to SIAH1 for the first 192 amino acids. PCR analysis detected both SIAH1 and SIAH1S in human heart, lymph node, testis, and fetal brain. PCR and Western blot analysis detected SIAH1 and SIAH1S transcripts and proteins in breast, kidney, and esophagus cancer tissues.