Physical and functional interactions between the transcription factor PU.1 and the coactivator CBP.
Yeast two-hybrid system was employed to isolate novel proteins that physically interact with PU.1, a member of Ets family transcription factors. Sequence analyses of several isolated clones positive for beta-galactosidase activity revealed that one of these clones was confirmed to encode a transcriptional coactivator, CREB binding protein (CBP). GST binding assay showed that the interacting sites were located at the transcriptional activation domain of PU.1 through 74-122 and the region spanning residues 1283-1915 of CBP. CBP potentiated PU.1-mediated transcription of the reporter gene driven by the multimerized PU.1-binding sites, suggesting that CBP functions as a coactivator for PU.1. Considering that CBP is a limited cellular component to function as a coactivator for several transcription factors, CBP may mediate synergistic and antagonistic interactions between PU.1 and other transcription factors during the process of hematopoietic cell differentiation.
Department of Cell Genetics, Sasaki Institute, Tokyo, Japan.
H
H
Yamamoto
F
F
Kihara-Negishi
T
T
Yamada
Y
Y
Hashimoto
T
T
Oikawa
D000818:Animals; D050882:CREB-Binding Protein; D051379:Mice; D009687:Nuclear Proteins / Q000235:genetics / Q000378:metabolism*; D011518:Proto-Oncogene Proteins / Q000235:genetics / Q000378:metabolism*; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000378:metabolism; D015534:Trans-Activators / Q000235:genetics / Q000378:metabolism*; D000099232:Proto-Oncogene Protein Spi-1
D050882:CREB-Binding Protein; D009687:Nuclear Proteins; D011518:Proto-Oncogene Proteins; D011993:Recombinant Fusion Proteins; D015534:Trans-Activators; D000099232:Proto-Oncogene Protein Spi-1; C494364:Crebbp protein, mouse