TopBP1 localises to centrosomes in mitosis and to chromosome cores in meiosis.
Topoisomerase IIbeta binding protein 1 (TopBP1), previously shown to localise to sites of DNA damage and to stalled replication forks, has been implicated in DNA replication and in DNA damage response. In this work we showed that TopBP1 was localised in structures other than stalled replication forks. In late mitosis TopBP1 localises to centrosomes in a manner similar to other DNA damage response proteins such as BRCA1 and p53. Spindle checkpoint activation does not affect this centrosomal localisation. Moreover, in the testis, we detected high levels of TopBP1 associated with meiotic prophase chromosome cores and the X-Y pair. Together, these data suggest a direct role of TopBP1 during both mitosis and meiotic prophase I.
Reini
Kaarina
K
Biocenter Oulu and Department of Biochemistry, P.O. Box 3000, 90014, University of Oulu, Finland.
Uitto
Lahja
L
Perera
David
D
Moens
Peter B
PB
Freire
Raimundo
R
Syväoja
Juhani E
JE
D000705:Anaphase; D019313:BRCA1 Protein / Q000032:analysis / Q000235:genetics; D002352:Carrier Proteins / Q000032:analysis* / Q000235:genetics / Q000502:physiology; D045744:Cell Line, Tumor; D018385:Centrosome / Q000737:chemistry*; D002875:Chromosomes / Q000737:chemistry* / Q000648:ultrastructure; D004268:DNA-Binding Proteins; D004789:Enzyme Activation; D005260:Female; D006367:HeLa Cells; D006801:Humans; D008297:Male; D049469:Meiotic Prophase I; D008677:Metaphase; D008938:Mitosis; D015739:Nocodazole / Q000494:pharmacology; D009687:Nuclear Proteins; D011743:Pyrimidines / Q000494:pharmacology; D013091:Spermatogenesis; D013737:Testis / Q000737:chemistry / Q000166:cytology; D013871:Thiones / Q000494:pharmacology; D013997:Time Factors
D019313:BRCA1 Protein; D002352:Carrier Proteins; D004268:DNA-Binding Proteins; D009687:Nuclear Proteins; D011743:Pyrimidines; C110513:TOPBP1 protein, human; D013871:Thiones; C400223:monastrol; D015739:Nocodazole