Linked Life Data

11152455

Source:http://linkedlifedata.com/resource/pubmed/id/11152455

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
14
pubmed:dateCreated
2001-4-3
pubmed:abstractText
The activity of the retinoblastoma protein pRB is regulated by phosphorylation that is mediated by G(1) cyclin-associated cyclin-dependent kinases (CDKs). Since the pRB-related pocket proteins p107 and p130 share general structures and biological functions with pRB, their activity is also considered to be regulated by phosphorylation. In this work, we generated phosphorylation-resistant p107 and p130 molecules by replacing potential cyclin-CDK phosphorylation sites with non-phosphorylatable alanine residues. These phosphorylation-resistant mutants retained the ability to bind E2F and cyclin. Upon introduction into p16(INK4a)-deficient U2-OS osteosarcoma cells, in which cyclin D-CDK4/6 is dysregulated, the phosphorylation-resistant mutants, but not wild-type p107 or p130, were capable of inhibiting cell proliferation. Furthermore, when ectopically expressed in pRB-deficient SAOS-2 osteosarcoma cells, the wild-type as well as the phosphorylation-resistant pRB family proteins were capable of inducing large flat cells. The flat cell-inducing activity of the wild-type proteins, but not that of the phosphorylation-resistant mutants, was abolished by coexpressing cyclin E. Our results indicate that the elevated cyclin D- or cyclin E-associated kinase leads to systemic inactivation of the pRB family proteins and suggest that dysregulation of the pRB kinase provokes an aberrant cell cycle in a broader range of cell types than those induced by genetic inactivation of the RB gene.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Apr
pubmed:issn
0021-9258
pubmed:author
pubmed:issnType
Print
pubmed:day
6
pubmed:volume
276
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
11362-70
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
2001
pubmed:articleTitle
Collective inhibition of pRB family proteins by phosphorylation in cells with p16INK4a loss or cyclin E overexpression.
pubmed:affiliation
Division of Molecular Oncology, Institute for Genetic Medicine, Hokkaido University, Kita-ku, Sapporo 060-0815, Japan.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't