Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
9
pubmed:dateCreated
2010-9-2
pubmed:abstractText
When vertebrate cells exit mitosis various cellular structures are re-organized to build functional interphase cells. This depends on Cdk1 (cyclin dependent kinase 1) inactivation and subsequent dephosphorylation of its substrates. Members of the protein phosphatase 1 and 2A (PP1 and PP2A) families can dephosphorylate Cdk1 substrates in biochemical extracts during mitotic exit, but how this relates to postmitotic reassembly of interphase structures in intact cells is not known. Here, we use a live-cell imaging assay and RNAi knockdown to screen a genome-wide library of protein phosphatases for mitotic exit functions in human cells. We identify a trimeric PP2A-B55alpha complex as a key factor in mitotic spindle breakdown and postmitotic reassembly of the nuclear envelope, Golgi apparatus and decondensed chromatin. Using a chemically induced mitotic exit assay, we find that PP2A-B55alpha functions downstream of Cdk1 inactivation. PP2A-B55alpha isolated from mitotic cells had reduced phosphatase activity towards the Cdk1 substrate, histone H1, and was hyper-phosphorylated on all subunits. Mitotic PP2A complexes co-purified with the nuclear transport factor importin-beta1, and RNAi depletion of importin-beta1 delayed mitotic exit synergistically with PP2A-B55alpha. This demonstrates that PP2A-B55alpha and importin-beta1 cooperate in the regulation of postmitotic assembly mechanisms in human cells.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
http://linkedlifedata.com/resource/pubmed/chemical/Cyclin-Dependent Kinases, http://linkedlifedata.com/resource/pubmed/chemical/Flavonoids, http://linkedlifedata.com/resource/pubmed/chemical/Histones, http://linkedlifedata.com/resource/pubmed/chemical/KPNB1 protein, human, http://linkedlifedata.com/resource/pubmed/chemical/Leupeptins, http://linkedlifedata.com/resource/pubmed/chemical/PPP2CA protein, human, http://linkedlifedata.com/resource/pubmed/chemical/PPP2R1A protein, human, http://linkedlifedata.com/resource/pubmed/chemical/PPP2R2A protein, human, http://linkedlifedata.com/resource/pubmed/chemical/Piperidines, http://linkedlifedata.com/resource/pubmed/chemical/Protein Phosphatase 2, http://linkedlifedata.com/resource/pubmed/chemical/RNA, Small Interfering, http://linkedlifedata.com/resource/pubmed/chemical/benzyloxycarbonylleucyl-leucyl-leuci..., http://linkedlifedata.com/resource/pubmed/chemical/beta Karyopherins, http://linkedlifedata.com/resource/pubmed/chemical/flavopiridol
pubmed:status
MEDLINE
pubmed:month
Sep
pubmed:issn
1476-4679
pubmed:author
pubmed:issnType
Electronic
pubmed:volume
12
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
886-93
pubmed:meshHeading
pubmed-meshheading:20711181-Cell Nucleus Division, pubmed-meshheading:20711181-Chromosomes, pubmed-meshheading:20711181-Cyclin-Dependent Kinases, pubmed-meshheading:20711181-Flavonoids, pubmed-meshheading:20711181-Golgi Apparatus, pubmed-meshheading:20711181-HeLa Cells, pubmed-meshheading:20711181-Histones, pubmed-meshheading:20711181-Humans, pubmed-meshheading:20711181-Image Processing, Computer-Assisted, pubmed-meshheading:20711181-Interphase, pubmed-meshheading:20711181-Leupeptins, pubmed-meshheading:20711181-Microscopy, Confocal, pubmed-meshheading:20711181-Microscopy, Fluorescence, pubmed-meshheading:20711181-Mitosis, pubmed-meshheading:20711181-Mitotic Spindle Apparatus, pubmed-meshheading:20711181-Models, Biological, pubmed-meshheading:20711181-Phosphorylation, pubmed-meshheading:20711181-Piperidines, pubmed-meshheading:20711181-Protein Binding, pubmed-meshheading:20711181-Protein Phosphatase 2, pubmed-meshheading:20711181-RNA, Small Interfering, pubmed-meshheading:20711181-RNA Interference, pubmed-meshheading:20711181-Transfection, pubmed-meshheading:20711181-beta Karyopherins
pubmed:year
2010
pubmed:articleTitle
Live-cell imaging RNAi screen identifies PP2A-B55alpha and importin-beta1 as key mitotic exit regulators in human cells.
pubmed:affiliation
Institute of Biochemistry, Swiss Federal Institute of Technology Zurich (ETHZ), Schafmattstrasse 18, CH-8093 Zurich, Switzerland.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't