title: Involvement of PIAS1 in the sumoylation of tumor suppressor p53.
abstract: Sumoylation of p53 by the ubiquitin-like protein, SUMO-1/sentrin/PIC1, has been shown to stimulate its transcriptional activation activity. The SUMO E3 ligase, a key enzyme in the recognition of substrates to be sumoylated, has not yet been identified. We isolated PIAS1 (protein inhibitor of activated STAT1) as a SUMO-1 binding protein by yeast two-hybrid screening. In addition, PIAS1 bound p53 and Ubc9, the E2 for SUMO. PIAS1 that was mutated in the RING finger-like domain bound p53 and SUMO-1, but not Ubc9. PIAS1 catalyzed the sumoylation of p53 both in U2OS cells and in vitro in a domain-dependent manner. These data suggest that PIAS1 functions as a SUMO ligase, or possibly as a tightly bound regulator of it, toward p53.
authors.affiliation: Tokyo University of Pharmacy and Life Science, School of Life Science, 1432-1 Horinouchi, Hachioji, Tokyo 192-0392, Japan.
authors.forename: T
authors.initials: T
authors.lastname: Kahyo
authors.forename: T
authors.initials: T
authors.lastname: Nishida
authors.forename: H
authors.initials: H
authors.lastname: Yasuda
mesh_terms: D000595:Amino Acid Sequence; D002458:Cell Fractionation; D002460:Cell Line; D017930:Genes, Reporter / Q000235:genetics; D006801:Humans; D015151:Immunoblotting; D008025:Ligases / Q000378:metabolism; D008969:Molecular Sequence Data; D011485:Protein Binding; D050828:Protein Inhibitors of Activated STAT; D017434:Protein Structure, Tertiary; D011506:Proteins / Q000737:chemistry / Q000378:metabolism*; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000378:metabolism; D025842:SUMO-1 Protein; D012441:Saccharomyces cerevisiae / Q000502:physiology; D016415:Sequence Alignment; D016159:Tumor Suppressor Protein p53 / Q000235:genetics / Q000378:metabolism*; D020798:Two-Hybrid System Techniques; D044763:Ubiquitin-Conjugating Enzymes; D014452:Ubiquitins / Q000378:metabolism*; D000098843:Ubiquitin-Conjugating Enzyme UBC9
chemical_list: D050828:Protein Inhibitors of Activated STAT; D011506:Proteins; D011993:Recombinant Fusion Proteins; D025842:SUMO-1 Protein; D016159:Tumor Suppressor Protein p53; D014452:Ubiquitins; D044763:Ubiquitin-Conjugating Enzymes; D008025:Ligases; D000098843:Ubiquitin-Conjugating Enzyme UBC9