RRC ID 68509
Author Ishida R, Takashima R, Koujin T, Shibata M, Nozaki N, Seto M, Mori H, Haraguchi T, Hiraoka Y.
Title Mitotic specific phosphorylation of serine-1212 in human DNA topoisomerase IIalpha.
Journal Cell Struct Funct
Abstract It is known that topoisomerase IIalpha is phosphorylated by several kinases. To elucidate the role of phosphorylation of topoisomerase IIalpha in the cell cycle, we have examined the cell cycle behavior of phosphorylated topoisomerase IIalpha in HeLa cells using antibodies against several phospho-oligopeptides of this enzyme. Here we demonstrate that serine1212 in topoisomerase IIalpha is phosphorylated only in the mitotic phase. Using an antibody against an oligopeptide containing phosphoserine-1212 in topoisomerase IIalpha (PS1212), subcellular localization of topoisomerase IIalpha phosphorylated at serine1212 was examined by indirect immunofluorescence staining, and compared with that of overall topoisomerase IIalpha. Serine1212-phosphorylated topoisomerase IIalpha was localized specifically on mitotic chromosomes, but not on interphase chromosomes; this result contrasts with overall topoisomerase IIalpha which was observed on chomosomes in both interphase and mitosis. Serine1212-phosphorylated topoisomerase lIalpha first appeared on chromosome arms in prophase, became concentrated on the centromeres in metaphase, and disappeared in early telophase. In addition, ICRF-193, a catalytic inhibitor of topoisomerase II, prevented accumulation of serine1212-phosphorylated topoisomerase IIalpha at the centromeres. These results indicate that serine1212 of topoisomerase IIalpha is phosphorylated specifically during mitosis, and suggest that the serine1212-phosphorylated topoisomerase IIalpha acts on resolving topological constraint progressively from the chromosome arm to the centromere during metaphase chromosome condensation.
Volume 26(4)
Pages 215-26
Published 2001-8-1
DOI 10.1247/csf.26.215
PMID 11699638
MeSH Antibodies, Monoclonal / immunology Antigens, Neoplasm Cell Cycle Centromere / enzymology Chromosomes / enzymology DNA Topoisomerases, Type II / chemistry* DNA Topoisomerases, Type II / immunology DNA Topoisomerases, Type II / metabolism* DNA-Binding Proteins Diketopiperazines Enzyme Inhibitors / pharmacology Flow Cytometry Fluorescent Antibody Technique, Indirect HeLa Cells Humans Microscopy, Fluorescence Mitosis Phosphorylation Piperazines / pharmacology Serine / metabolism* Topoisomerase II Inhibitors
IF 2.429
Human and Animal Cells HeLa(RCB0007)