This is specific for human SIAH2 and Drosophila SINA in proliferating cells and stem cells. This does not detect Drosophila SINAH or normal, nondividing cells.
SIAH-2 (seven in absentia homolog 2) is an E3 ligase that catalyzes ubiquitination and proteasome-mediated degradation of protein substrates. SIAH-2 encodes a 324 amino acid protein that shares 77% identity with human SIAH-1 and 68% identity with the Drosophila sina (seven in absentia) gene, on which development of the Drosophila R7 photoreceptor is dependent. SIAH-2 targets TRAF2 (which regulates cell responses to stress and cytokines through the regulation of key stress-signaling cascades) for degradation under stress conditions such as hypoxia. It targets HIF-1 alpha prolyl hydroxylase 3 (PHD3) for degradation upon exposure to hypoxic conditions, which coincides with an increase in SIAH-2 transcription. SIAH-2 can decrease TNF-alpha-dependent induction of JNK activity and transcriptional activation of NFkB. SIAH-2 null mice subjected to hypoxia display an impaired respiratory response and reduced levels of hemoglobin.
Protein Aliases: E3 ubiquitin-protein ligase SIAH2; EC 6.3.2; RING-type E3 ubiquitin transferase SIAH2; Seven in absentia homolog 2; Siah-2
Gene Aliases: hSiah2; SIAH2
UniProt ID: (Human) O43255