Abstract
Recent experiments have shown that the E2F transcription factor is in a complex with the RB1 gene product. The E2F-pRB complex can be reconstituted in an in vitro assay using a GST-RB fusion protein isolated from Escherichia coli. This interaction is dependent on pRB sequences involved in E1A/T-antigen binding as well as carboxy-terminal pRB sequences that are not necessary for E1A/T binding. Moreover, reconstitution assays reveal a requirement for an accessory factor, in addition to E2F and pRB, for formation of the E2F-pRB complex. Assays of transcription from the adenovirus E2 promoter in transfection experiments demonstrate that formation of the complex containing pRB and E2F coincides with an inhibition of E2F-dependent transcriptional activity. A mutant pRB protein that does not associate with E2F does not inhibit transcription. We conclude that as a consequence of its interaction with E2F, pRB may regulate the transcriptional function of the E2F factor.
Publication types
-
Research Support, Non-U.S. Gov't
MeSH terms
-
Adenovirus Early Proteins
-
Antigens, Viral, Tumor / genetics
-
Antigens, Viral, Tumor / metabolism
-
Carrier Proteins*
-
Cell Cycle Proteins*
-
Chloramphenicol O-Acetyltransferase / genetics
-
Chloramphenicol O-Acetyltransferase / metabolism
-
DNA-Binding Proteins*
-
E2F Transcription Factors
-
Genes, Retinoblastoma
-
HeLa Cells
-
Humans
-
Mutation / genetics
-
Oncogene Proteins, Viral / genetics
-
Oncogene Proteins, Viral / metabolism
-
Precipitin Tests
-
Promoter Regions, Genetic
-
Recombinant Fusion Proteins / genetics
-
Recombinant Fusion Proteins / metabolism
-
Retinoblastoma Protein / genetics
-
Retinoblastoma Protein / metabolism*
-
Retinoblastoma-Binding Protein 1
-
Transcription Factor DP1
-
Transcription Factors / genetics
-
Transcription Factors / metabolism*
-
Transcription, Genetic / physiology*
Substances
-
Adenovirus Early Proteins
-
Antigens, Viral, Tumor
-
Carrier Proteins
-
Cell Cycle Proteins
-
DNA-Binding Proteins
-
E2F Transcription Factors
-
Oncogene Proteins, Viral
-
Recombinant Fusion Proteins
-
Retinoblastoma Protein
-
Retinoblastoma-Binding Protein 1
-
Transcription Factor DP1
-
Transcription Factors
-
Chloramphenicol O-Acetyltransferase