Seven In Absentia Homolog 3 (SIAH3)

SIAH3 Belongs to the SINA (Seven in absentia) family.Contains 1 SIAH-type zinc finger.The seven in absentia (sina) gene was first identified in Drosophila. The Drosophila Sina protein is essential for the determination of the R7 pathway in photoreceptor cell development: the loss of functional Sina results in the transformation of the R7 precursor cell to a non-neuronal cell type.The Sina protein contains an N-terminal RING finger domain C3HC4-type. Through this domain, Sina binds E2 ubiquitin-conjugating enzymes (UbcD1) Sina also interacts with Tramtrack (TTK88) via PHYL. Tramtrack is a transcriptional repressor that blocks photoreceptor determination, while PHYL down-regulates the activity of TTK88. In turn, the activity of PHYL requires the activation of the Sevenless receptor tyrosine kinase, a process essential for R7 determination.