PIAS1

This gene encodes a member of the protein inhibitor of activated STAT (PIAS) family. PIAS proteins function as SUMO E3 ligases and play important roles in many cellular processes by mediating the sumoylation of target proteins. This protein plays a central role as a transcriptional coregulator of numerous cellular pathways includign the STAT1 and nuclear factor kappaB pathways. Alternate splicing results in multiple transcript variants. [provided by RefSeq, Mar 2016]

Full Name

Protein Inhibitor Of Activated STAT 1

Function

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. Plays a crucial role as a transcriptional coregulation in various cellular pathways, including the STAT pathway, the p53 pathway and the steroid hormone signaling pathway. In vitro, binds A/T-rich DNA. The effects of this transcriptional coregulation, transactivation or silencing, may vary depending upon the biological context. Sumoylates PML (at'Lys-65' and 'Lys-160') and PML-RAR and promotes their ubiquitin-mediated degradation. PIAS1-mediated sumoylation of PML promotes its interaction with CSNK2A1/CK2 which in turn promotes PML phosphorylation and degradation (By similarity).
Enhances the sumoylation of MTA1 and may participate in its paralog-selective sumoylation. Plays a dynamic role in adipogenesis by promoting the SUMOylation and degradation of CEBPB (By similarity).

Biological Process

Fat cell differentiationIEA:Ensembl
Negative regulation of transcription by RNA polymerase IIIEA:Ensembl
Positive regulation of proteasomal ubiquitin-dependent protein catabolic processISS:UniProtKB
Positive regulation of protein sumoylationManual Assertion Based On ExperimentIDA:UniProtKB
Protein sumoylationManual Assertion Based On ExperimentIDA:BHF-UCL
Receptor signaling pathway via JAK-STATManual Assertion Based On ExperimentTAS:ProtInc
Regulation of cell population proliferationISS:UniProtKB
Regulation of transcription by RNA polymerase IIManual Assertion Based On ExperimentIBA:GO_Central

Cellular Location

Nucleus speckle
Nucleus, PML body
Interaction with CSRP2 may induce a partial redistribution along the cytoskeleton.

PTM

Sumoylated.