Steroid receptor coactivator-1 coactivates activating protein-1-mediated transactivations through interaction with the c-Jun and c-Fos subunits.
Steroid receptor coactivator-1 (SRC-1) specifically bound to the transcription factor AP-1 subunits c-Jun and c-Fos, as demonstrated by the yeast two-hybrid tests and glutathione S-transferase pull down assays. The c-Jun and c-Fos binding sites were localized to the C-terminal subregion of SRC-1 (amino acids 1101-1441) that encompasses the previously described histone acetyltransferase and receptor-binding domains. In mammalian cells, SRC-1, similar to the previous results with CBP-p300 (Arias, J., Alberts, A. S., Brindle, P., Claret, F. X., Smeal, T., Karin, M., Feramisco, J., and Montminy, M. (1994) Nature 370, 226-229; Bannister, A. J., and Kouzarides, T. (1995) EMBO J. 14, 4758-4762), potentiated the AP-1-mediated transactivations in a dose-dependent manner and derepressed the mutual inhibitions between nuclear receptors and AP-1. Furthermore, coexpression of p300 further enhanced this SRC-1-potentiated level of transactivations. Thus, we concluded that at least two distinct coactivator molecules may cooperate to regulate AP-1-dependent transactivations and mediate transrepression between AP-1 and nuclear receptors in vivo.
Lee
S K
SK
College of Pharmacy, Chonnam National University, Kwangju 500-757, Korea.
Kim
H J
HJ
Na
S Y
SY
Kim
T S
TS
Choi
H S
HS
Im
S Y
SY
Lee
J W
JW
D000123:Acetyltransferases / Q000378:metabolism; D018797:Cell Cycle Proteins / Q000378:metabolism; D002460:Cell Line; D051548:Histone Acetyltransferases; D056920:Nuclear Receptor Coactivator 1; D011485:Protein Binding; D016760:Proto-Oncogene Proteins c-fos / Q000378:metabolism*; D016755:Proto-Oncogene Proteins c-jun / Q000378:metabolism*; D018160:Receptors, Cytoplasmic and Nuclear / Q000378:metabolism; D018808:Transcription Factor AP-1 / Q000378:metabolism*; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism*; D015533:Transcriptional Activation; D014162:Transfection; D050880:p300-CBP Transcription Factors; D000099224:p300-CBP-Associated Factor
D000123:Acetyltransferases; D018797:Cell Cycle Proteins; D051548:Histone Acetyltransferases; D056920:Nuclear Receptor Coactivator 1; D016760:Proto-Oncogene Proteins c-fos; D016755:Proto-Oncogene Proteins c-jun; D018160:Receptors, Cytoplasmic and Nuclear; D018808:Transcription Factor AP-1; D014157:Transcription Factors; D050880:p300-CBP Transcription Factors; D000099224:p300-CBP-Associated Factor