Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
3
pubmed:dateCreated
2004-11-4
pubmed:abstractText
To ensure the fidelity of chromosome segregation, the spindle checkpoint blocks the ubiquitin ligase activity of APC/C(Cdc20) in response to a single chromatid not properly attached to the mitotic spindle. Here we show that HeLa cells depleted for Bub1 by RNA interference are defective in checkpoint signaling. Bub1 directly phosphorylates Cdc20 in vitro and inhibits the ubiquitin ligase activity of APC/C(Cdc20) catalytically. A Cdc20 mutant with all six Bub1 phosphorylation sites removed is refractory to Bub1-mediated phosphorylation and inhibition in vitro. Upon checkpoint activation, Bub1 itself is hyperphosphorylated and its kinase activity toward Cdc20 is stimulated. Ectopic expression of the nonphosphorylatable Cdc20 mutant allows HeLa cells to escape from mitosis in the presence of spindle damage. Therefore, Bub1-mediated phosphorylation of Cdc20 is required for proper checkpoint signaling. We speculate that inhibition of APC/C(Cdc20) by Bub1 in a catalytic fashion may partly account for the exquisite sensitivity of the spindle checkpoint.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
http://linkedlifedata.com/resource/pubmed/chemical/Bub1 spindle checkpoint protein, http://linkedlifedata.com/resource/pubmed/chemical/CDC20 protein, human, http://linkedlifedata.com/resource/pubmed/chemical/Cell Cycle Proteins, http://linkedlifedata.com/resource/pubmed/chemical/Protein Kinases, http://linkedlifedata.com/resource/pubmed/chemical/Protein-Serine-Threonine Kinases, http://linkedlifedata.com/resource/pubmed/chemical/Serine, http://linkedlifedata.com/resource/pubmed/chemical/Threonine, http://linkedlifedata.com/resource/pubmed/chemical/Ubiquitin, http://linkedlifedata.com/resource/pubmed/chemical/Ubiquitin-Conjugating Enzymes, http://linkedlifedata.com/resource/pubmed/chemical/Ubiquitin-Protein Ligase Complexes, http://linkedlifedata.com/resource/pubmed/chemical/anaphase-promoting complex
pubmed:status
MEDLINE
pubmed:month
Nov
pubmed:issn
1097-2765
pubmed:author
pubmed:issnType
Print
pubmed:day
5
pubmed:volume
16
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
387-97
pubmed:dateRevised
2009-11-19
pubmed:meshHeading
pubmed:year
2004
pubmed:articleTitle
Phosphorylation of Cdc20 by Bub1 provides a catalytic mechanism for APC/C inhibition by the spindle checkpoint.
pubmed:affiliation
Department of Pharmacology, The University of Texas Southwestern Medical Center at Dallas, 5323 Harry Hines Boulevard, Dallas, TX 75390, USA.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, Non-U.S. Gov't