PIAS2: ProductsProtein Inhibitor of Activated STAT, 2 (PIAS2), also known as PIASx, ARIP3, DIP, and MIZ1, is one member of the PIAS family of molecules. At least three isoforms have thus far been described: PIAS2 alpha, PIAS2 beta, and PIAS-NY. PIAS2 beta is the canonical isoform. It is 621 amino acids (aa) in length and has a predicted molecular weight of 68.2 kDa. PIAS2 alpha has a 22 aa substitution at aa 551-572, followed by a truncation after aa 572. PIAS-NY has a 12 aa substitution at aa 1-8 and ends at aa 401. PIAS2 alpha and PIAS-NY have predicted molecular weights of 63.4 and 45.1 kDa, respectively. Human PIAS2 shares 98% aa seqeunce identity with the mouse and rat orthologs. It contains several domains conserved among all PIAS family members. These domains include an N-terminal SAP domain that contains the LXXLL signature motif, which mediates interactions between nuclear receptors and regulatory proteins, a PINIT motif, a RING finger-like zinc binding domain, and a highly acidic region that contains a putative SUMO-interaction motif. PIAS proteins function as RING-type small Ubiquitin-related modifier (SUMO) ligases. They regulate several signal transduction pathways, including the Jak/STAT pathway, p53 pathway, and steroid hormone receptor signaling, by acting as transcriptional coregulators. PIAS2 has been shown to SUMOylate STAT proteins, p53, p73 alpha, c-Jun, MDM2, Oct4, and SOX2. PIAS2 has also been shown to modulate the activities transcription factors by mechanisms other than SUMOylation.