PIAS4
Description
The PIAS4 (protein inhibitor of activated STAT 4) is a protein-coding gene located on chromosome 19.
PIAS4, also known as PIASg or PIASy, is an enzyme that is encoded by the PIAS4 gene in humans. It is a member of the protein inhibitor of activated STAT (PIAS) family and functions as an E3 SUMO-protein ligase. PIAS4 has been shown to interact with Mothers against decapentaplegic homolog 6, Mothers against decapentaplegic homolog 7, and Lymphoid enhancer-binding factor 1.
PIAS4 acts as an E3-type SUMO ligase, promoting the attachment of SUMO (small ubiquitin-like modifier) proteins to other proteins. It stabilizes the interaction between the SUMO-conjugating enzyme UBE2I and the target protein, facilitating the SUMOylation process. PIAS4 also functions as a SUMO-tethering factor, bringing SUMO and its target protein together. It has been shown to mediate the sumoylation of several proteins, including CEBPA, PARK7, HERC2, MYB, TCF4, and RNF168. PIAS4 plays a crucial role in regulating gene expression and cellular processes. It participates in various signaling pathways, including the STAT pathway, the p53/TP53 pathway, the Wnt pathway, and steroid hormone signaling. PIAS4 is involved in gene silencing and has been shown to repress LEF1 and enhance TCF4 transcriptional activities in the Wnt pathway through SUMOylation. It also enhances the sumoylation of MTA1, a protein involved in chromatin remodeling. PIAS4 binds to specific DNA sequences known as matrix or scaffold attachment regions (MARs/SARs). It has been implicated in DNA damage repair by catalyzing the conjugation of SUMO2 to KAT5, which facilitates the repair of double-strand breaks via homologous recombination (HR). PIAS4 also mediates the sumoylation of PARP1 in response to its trapping to chromatin. PIAS4's activity has been linked to various cellular processes, including cell cycle progression, response to reactive oxygen species (ROS), and regulation of gene expression.
PIAS4 is also known as PIAS-gamma, PIASY, Piasg, ZMIZ6.
