Document Detail


E2F-4 switches from p130 to p107 and pRB in response to cell cycle reentry.
MedLine Citation:
PMID:  8657117     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
The E2F transcription factor couples the coordinate expression of cell cycle proteins to their appropriate transition points. Its activity is controlled by the cell cycle regulators pRB, p107, and p130. These bind to E2F at defined but distinct stages of the cell cycle. Using specific antisera, we have identified the DP and E2F components of each of these species. Although present at very different levels, DP-1 and DP-2 are evenly distributed among each of these complexes. In contrast, the individual E2Fs have distinctly different binding profiles. Consistent with previous studies, E2F-1, E2F-2, and E2F-3 bind specifically to the retinoblastoma protein. In each case, their expression and DNA binding activity are restricted to post-G1/S fractions. Surprisingly, E2F-1 and E2F-3 make unequal contributions to the pRB-associated and free E2F activity, suggesting that these proteins perform different cell cycle functions. Most significantly, this study showed E2F-4 accounts for the vast majority of the endogenous E2F activity. In arrested cells, E2F-4 is sequestered by the p130 protein. However, as the cells pass the G1-to-S transition, the levels of pRB and p107 increase and E2F-4 now associates with both of these regulators. Despite this, a considerable amount of E2F-4 exists as free E2F. In G1 cells, this accounts for almost all of the free activity. Once the cells enter S phase, free E2F is composed of an equal mixture of E2F-4 and E2F-1.
Authors:
K Moberg; M A Starz; J A Lees
Related Documents :
9134027 - Separation by counterflow centrifugal elutriation and analysis of t- and b-lymphocytic ...
16631397 - New insights into the cell cycle profile of paracoccidioides brasiliensis.
20139697 - Role of cell cycle regulators in lung carcinogenesis.
18931307 - Nuclear akt interacts with b23/npm and protects it from proteolytic cleavage, enhancing...
4041887 - Differences in density and distribution of surface glycoconjugates between normal and d...
16944417 - Extracellular matrix of the developing ovarian follicle.
Publication Detail:
Type:  Journal Article; Research Support, U.S. Gov't, P.H.S.    
Journal Detail:
Title:  Molecular and cellular biology     Volume:  16     ISSN:  0270-7306     ISO Abbreviation:  Mol. Cell. Biol.     Publication Date:  1996 Apr 
Date Detail:
Created Date:  1996-07-29     Completed Date:  1996-07-29     Revised Date:  2009-11-19    
Medline Journal Info:
Nlm Unique ID:  8109087     Medline TA:  Mol Cell Biol     Country:  UNITED STATES    
Other Details:
Languages:  eng     Pagination:  1436-49     Citation Subset:  IM    
Affiliation:
Center for Cancer Research, Massachusetts Institute of Technology, Cambridge, 02139, USA.
Export Citation:
APA/MLA Format     Download EndNote     Download BibTex
MeSH Terms
Descriptor/Qualifier:
Antibodies, Monoclonal
Base Sequence
Blotting, Western
Carrier Proteins*
Cell Cycle / genetics*
Cell Cycle Proteins / metabolism*
DNA-Binding Proteins / biosynthesis*
E2F Transcription Factors
E2F1 Transcription Factor
E2F2 Transcription Factor
E2F3 Transcription Factor
E2F4 Transcription Factor
Humans
Molecular Sequence Data
Nuclear Proteins / biosynthesis*
Oligonucleotide Probes
Phosphoproteins / biosynthesis*
Proteins*
Retinoblastoma Protein / biosynthesis*
Retinoblastoma-Binding Protein 1
Retinoblastoma-Like Protein p107
Retinoblastoma-Like Protein p130
Transcription Factor DP1
Transcription Factors / biosynthesis*
Tumor Cells, Cultured
Grant Support
ID/Acronym/Agency:
NIH/NCI S.P30-CA14051-23/CA/NCI NIH HHS
Chemical
Reg. No./Substance:
0/Antibodies, Monoclonal; 0/Carrier Proteins; 0/Cell Cycle Proteins; 0/DNA-Binding Proteins; 0/E2F Transcription Factors; 0/E2F1 Transcription Factor; 0/E2F1 protein, human; 0/E2F2 Transcription Factor; 0/E2F2 protein, human; 0/E2F3 Transcription Factor; 0/E2F3 protein, human; 0/E2F4 Transcription Factor; 0/E2F4 protein, human; 0/Nuclear Proteins; 0/Oligonucleotide Probes; 0/Phosphoproteins; 0/Proteins; 0/RBL1 protein, human; 0/RBL2 protein, human; 0/Retinoblastoma Protein; 0/Retinoblastoma-Binding Protein 1; 0/Retinoblastoma-Like Protein p107; 0/Retinoblastoma-Like Protein p130; 0/TFDP1 protein, human; 0/Transcription Factor DP1; 0/Transcription Factors
Comments/Corrections

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine


Previous Document:  Identification of two RNA-binding proteins in Balbiani ring premessenger ribonucleoprotein granules ...
Next Document:  Functional interactions of phosphatidylinositol 3-kinase with GTPase-activating protein in 3T3-L1 ad...