The activation domain of transcription factor PU.1 binds the retinoblastoma (RB) protein and the transcription factor TFIID in vitro: RB shows sequence similarity to TFIID and TFIIB.
The retinoblastoma (RB) tumor suppressor protein and the TATA-box-binding protein TFIID form contacts with a number of viral transactivator proteins. One of these, the adenovirus E1A protein, can bind to both proteins. Here we present evidence that the cellular transcription factor PU.1 can bind to both RB and TFIID. Like E1A, PU.1 binds to the conserved C-terminal domain of TFIID and to the RB "pocket" domain. The PU.1 sequences required to bind either protein lie within a 75-amino acid region which functions as an independent activation domain in vivo. The ability of PU.1 to contact directly both RB and TFIID through the same 75-residue domain prompted us to look for sequence similarity between these two proteins. We find that the previously defined domain A of the RB pocket shows sequence similarity to the conserved C terminus of TFIID, whereas domain B shows sequence similarity to a second general transcription factor, TFIIB. The potential for RB to influence transcription by using TFIID- and TFIIB-related functions is discussed.
Hagemeier
C
C
Wellcome/CRC Institute, University of Cambridge, United Kingdom.
Bannister
A J
AJ
Cook
A
A
Kouzarides
T
T
D000595:Amino Acid Sequence; D000818:Animals; D001665:Binding Sites; D015153:Blotting, Western; D002478:Cells, Cultured; D003001:Cloning, Molecular; D004247:DNA / Q000235:genetics; D004268:DNA-Binding Proteins / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D004591:Electrophoresis, Polyacrylamide Gel; D016161:Genes, Retinoblastoma; D005982:Glutathione Transferase / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism; D006801:Humans; D051379:Mice; D008969:Molecular Sequence Data; D011485:Protein Binding; D011993:Recombinant Fusion Proteins / Q000302:isolation & purification / Q000378:metabolism; D015183:Restriction Mapping; D016160:Retinoblastoma Protein / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D015682:Retroviridae Proteins, Oncogenic; D017386:Sequence Homology, Amino Acid; D035581:Transcription Factor TFIIB; D035362:Transcription Factor TFIID; D014157:Transcription Factors / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D014162:Transfection
D004268:DNA-Binding Proteins; D011993:Recombinant Fusion Proteins; D016160:Retinoblastoma Protein; D015682:Retroviridae Proteins, Oncogenic; D035581:Transcription Factor TFIIB; D035362:Transcription Factor TFIID; D014157:Transcription Factors; C062022:v-Spi-1 protein, Friend spleen focus-forming virus; D004247:DNA; D005982:Glutathione Transferase