Cell cycle-specific association of E2F with the p130 E1A-binding protein.
Association of the E2F transcription factor with the pRb and p107 proteins appears to regulate the activity of E2F and, in turn, affect cell cycle progression. We found, however, that pRb and p107 are only minor E2F-associated proteins in G0/G1 mouse fibroblasts, and we sought to identify the major E2F partner protein in these cells. Because the adenovirus E1A oncoprotein seemed able to bind to the G0 E2F partner, we enriched for proteins that associated both with an E2F-binding site DNA column and with E1A. The major species in G0 and early G1 fibroblasts detected with this approach had properties identical to the pRb- and p107-related p130 protein. In serum-stimulated cells, p107 replaced p130 as the major E2F-associated protein near the G1/S border, concomitant with an increase in p107 protein levels. p130-E2F complexes resembled p107-E2F complexes in their ability to bind to cyclin-cdk kinases, and they appeared to be associated with the cyclin E-cdk2 kinase in late G1 cells. These observations indicate that E2F transcription factors are regulated by a succession of partner proteins with which they associate during defined stages of the cell cycle.
Cobrinik
D
D
Whitehead Institute for Biomedical Research, Cambridge Massachusetts 02142.
Whyte
P
P
Peeper
D S
DS
Jacks
T
T
Weinberg
R A
RA
D016475:3T3 Cells; D017500:Adenovirus E1A Proteins / Q000378:metabolism*; D000818:Animals; D000911:Antibodies, Monoclonal; D001483:Base Sequence; D002352:Carrier Proteins; D002453:Cell Cycle / Q000502:physiology*; D018797:Cell Cycle Proteins; D002478:Cells, Cultured; D016213:Cyclins / Q000378:metabolism; D004268:DNA-Binding Proteins; D050684:E2F Transcription Factors; D016193:G1 Phase / Q000502:physiology; D051379:Mice; D008807:Mice, Inbred BALB C; D008969:Molecular Sequence Data; D009687:Nuclear Proteins; D010750:Phosphoproteins; D011485:Protein Binding; D011494:Protein Kinases / Q000378:metabolism; D011506:Proteins / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D016192:Resting Phase, Cell Cycle / Q000502:physiology; D016160:Retinoblastoma Protein / Q000378:metabolism; D056465:Retinoblastoma-Binding Protein 1; D050720:Retinoblastoma-Like Protein p107; D050717:Retinoblastoma-Like Protein p130; D050680:Transcription Factor DP1; D014157:Transcription Factors / Q000378:metabolism / Q000502:physiology*
D017500:Adenovirus E1A Proteins; D000911:Antibodies, Monoclonal; C533431:Arid4a protein, mouse; D002352:Carrier Proteins; D018797:Cell Cycle Proteins; D016213:Cyclins; D004268:DNA-Binding Proteins; D050684:E2F Transcription Factors; D009687:Nuclear Proteins; D010750:Phosphoproteins; D011506:Proteins; C489485:Rbl1 protein, mouse; C493838:Rbl2 protein, mouse; D016160:Retinoblastoma Protein; D056465:Retinoblastoma-Binding Protein 1; D050720:Retinoblastoma-Like Protein p107; D050717:Retinoblastoma-Like Protein p130; D050680:Transcription Factor DP1; D014157:Transcription Factors; D011494:Protein Kinases