title: PICH promotes mitotic chromosome segregation: Identification of a novel role in rDNA disjunction.
abstract: PICH is an SNF2-family DNA translocase that appears to play a role specifically in mitosis. Characterization of PICH in human cells led to the initial discovery of "ultra-fine DNA bridges" (UFBs) that connect the 2 segregating DNA masses in the anaphase of mitosis. These bridge structures, which arise from specific regions of the genome, are a normal feature of anaphase but had escaped detection previously because they do not stain with commonly used DNA dyes. Nevertheless, UFBs are important for genome maintenance because defects in UFB resolution can lead to cytokinesis failure. We reported recently that PICH stimulates the unlinking (decatenation) of entangled DNA by Topoisomerase IIα (Topo IIα), and is important for the resolution of UFBs. We also demonstrated that PICH and Topo IIα co-localize at the rDNA (rDNA). In this Extra View article, we discuss the mitotic roles of PICH and explore further the role of PICH in the timely segregation of the rDNA locus.
authors: a Center for Chromosome Stability , Department of Cellular and Molecular Medicine , University of Copenhagen , Copenhagen , Denmark.|b Chromosome Research, Murdoch Children's Research Institute, Royal Children's Hospital , Parkville , VIC , Australia.
authors: Christian F
authors: CF
authors: Nielsen
authors: a Center for Chromosome Stability , Department of Cellular and Molecular Medicine , University of Copenhagen , Copenhagen , Denmark.
authors: Ian D
authors: ID
authors: Hickson
mesh_terms: D000818:Animals; D002460:Cell Line; D002645:Chickens; D020090:Chromosome Segregation / Q000235:genetics*; D004265:DNA Helicases / Q000378:metabolism*; D004275:DNA, Ribosomal / Q000235:genetics*; D006801:Humans; D008938:Mitosis / Q000235:genetics*; D008954:Models, Biological; D009630:Nondisjunction, Genetic; D014158:Transcription, Genetic
chemical_list: D004275:DNA, Ribosomal; D004265:DNA Helicases; C516980:ERCC6L protein, human
keywords: Chromosome condensation; DNA translocases; mitosis; topoisomerase II; ultra-fine bridges