title: SUMOylation regulates polo-like kinase 1-interacting checkpoint helicase (PICH) during mitosis.
abstract: Mitotic SUMOylation has an essential role in faithful chromosome segregation in eukaryotes, although its molecular consequences are not yet fully understood. In Xenopus egg extract assays, we showed that poly(ADP-ribose) polymerase 1 (PARP1) is modified by SUMO2/3 at mitotic centromeres and that its enzymatic activity could be regulated by SUMOylation. To determine the molecular consequence of mitotic SUMOylation, we analyzed SUMOylated PARP1-specific binding proteins. We identified Polo-like kinase 1-interacting checkpoint helicase (PICH) as an interaction partner of SUMOylated PARP1 in Xenopus egg extract. Interestingly, PICH also bound to SUMOylated topoisomerase IIα (TopoIIα), a major centromeric small ubiquitin-like modifier (SUMO) substrate. Purified recombinant human PICH interacted with SUMOylated substrates, indicating that PICH directly interacts with SUMO, and this interaction is conserved among species. Further analysis of mitotic chromosomes revealed that PICH localized to the centromere independent of mitotic SUMOylation. Additionally, we found that PICH is modified by SUMO2/3 on mitotic chromosomes and in vitro. PICH SUMOylation is highly dependent on protein inhibitor of activated STAT, PIASy, consistent with other mitotic chromosomal SUMO substrates. Finally, the SUMOylation of PICH significantly reduced its DNA binding capability, indicating that SUMOylation might regulate its DNA-dependent ATPase activity. Collectively, our findings suggest a novel SUMO-mediated regulation of the function of PICH at mitotic centromeres.
authors.affiliation: From the Department of Molecular Biosciences, University of Kansas, Lawrence, Kansas 66045.
authors.forename: Vinidhra
authors.initials: V
authors.lastname: Sridharan
authors.affiliation: From the Department of Molecular Biosciences, University of Kansas, Lawrence, Kansas 66045.
authors.forename: Hyewon
authors.initials: H
authors.lastname: Park
authors.affiliation: From the Department of Molecular Biosciences, University of Kansas, Lawrence, Kansas 66045.
authors.forename: Hyunju
authors.initials: H
authors.lastname: Ryu
authors.affiliation: From the Department of Molecular Biosciences, University of Kansas, Lawrence, Kansas 66045 azumay@ku.edu.
authors.forename: Yoshiaki
authors.initials: Y
authors.lastname: Azuma
mesh_terms: D000818:Animals; D000951:Antigens, Neoplasm / Q000378:metabolism; D002503:Centromere / Q000378:metabolism; D004265:DNA Helicases / Q000378:metabolism*; D004250:DNA Topoisomerases, Type II / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000378:metabolism; D006801:Humans; D008938:Mitosis; D000071137:Poly (ADP-Ribose) Polymerase-1; D011065:Poly(ADP-ribose) Polymerases / Q000378:metabolism; D011485:Protein Binding; D050828:Protein Inhibitors of Activated STAT / Q000378:metabolism; D021381:Protein Transport; D025841:Small Ubiquitin-Related Modifier Proteins / Q000378:metabolism; D058207:Sumoylation; D014452:Ubiquitins / Q000378:metabolism; D014981:Xenopus
chemical_list: D000951:Antigens, Neoplasm; D004268:DNA-Binding Proteins; D050828:Protein Inhibitors of Activated STAT; C117909:SUMO2 protein, human; C492189:SUMO3 protein, human; D025841:Small Ubiquitin-Related Modifier Proteins; D014452:Ubiquitins; C499320:PARP1 protein, human; D000071137:Poly (ADP-Ribose) Polymerase-1; D011065:Poly(ADP-ribose) Polymerases; D004265:DNA Helicases; C587425:ERCC6L2 protein, human; D004250:DNA Topoisomerases, Type II
keywords: Centromere; Mitosis; PICH; SUMO; SUMO-interacting Motif (SIM); Sumoylation; Xenopus