PIAS4, PIASG, E3 SUMO-protein ligase PIAS4, PIASy, Protein inhibitor of activated STAT protein 4, Protein inhibitor of activated STAT protein gamma

PIASy1 functions as an E3-type small ubiquitin-like modifier (SUMO) ligase, stabilizing the interaction between UBE2I and the substrate, and as a SUMO-tethering factor. This protein plays a crucial role in transcriptional coregulation of various cellular pathways, including the STAT pathway, the p53 pathway, the wnt pathway and the steroid hormone signaling pathway. PIASy1 is involved in gene silencing, and promotes PARK7 sumoylation.