Characterization of the transcriptional regulator YY1. The bipartite transactivation domain is independent of interaction with the TATA box-binding protein, transcription factor IIB, TAFII55, or cAMP-responsive element-binding protein (CPB)-binding protein.
YY1 is a multifunctional transcription factor implicated in both positive and negative regulation of gene expression as well as in initiation of transcription. We show that YY1 is ubiquitously expressed in growing, differentiated, and growth-arrested cells. The protein is phosphorylated and has a half-life of 3.5 h. To define functional domains, we have generated a large panel of YY1 mutant proteins. These were used to define precisely the DNA-binding domain, the region responsible for nuclear localization, and the transactivation domain. The two acidic domains at the N terminus each provide about half of the transcriptional activating activity. Furthermore, the spacer region between the Gly/Ala-rich and zinc finger domains has accessory function in transactivation. YY1 has been shown previously to bind to TAFII55, TATA box-binding protein, transcription factor IIB, and p300. In addition, we identified cAMP-responsive element-binding protein (CBP)-binding protein as a YY1 binding partner. Surprisingly, these proteins did not bind to the domains involved in transactivation, but rather to the zinc finger and Gly/Ala-rich domains of YY1. Thus, these proteins do not explain the transcriptional activating activity of YY1, but rather may be involved in repression or in initiation.
Austen
M
M
Institut für Molekularbiologie, Medizinische Hochschule Hannover, Carl-Neuberg-Strasse 1, 30623 Hannover, Federal Republic of Germany.
Lüscher
B
B
Lüscher-Firzlaff
J M
JM
D016475:3T3 Cells; D000818:Animals; D002373:Cyclic AMP Receptor Protein / Q000378:metabolism*; D004268:DNA-Binding Proteins / Q000378:metabolism*; D050981:Erythroid-Specific DNA-Binding Factors; D006367:HeLa Cells; D006801:Humans; D051379:Mice; D016716:PC12 Cells; D011485:Protein Binding; D011817:Rabbits; D051381:Rats; D016385:TATA Box; D035381:TATA-Binding Protein Associated Factors; D035181:TATA-Box Binding Protein; D015534:Trans-Activators / Q000378:metabolism*; D035581:Transcription Factor TFIIB; D035362:Transcription Factor TFIID; D014157:Transcription Factors / Q000378:metabolism*; D014158:Transcription, Genetic; D050986:YY1 Transcription Factor
D002373:Cyclic AMP Receptor Protein; D004268:DNA-Binding Proteins; D050981:Erythroid-Specific DNA-Binding Factors; C091537:TAF7 protein, human; D035381:TATA-Binding Protein Associated Factors; D035181:TATA-Box Binding Protein; D015534:Trans-Activators; D035581:Transcription Factor TFIIB; D035362:Transcription Factor TFIID; D014157:Transcription Factors; D050986:YY1 Transcription Factor; C494698:YY1 protein, human; C494699:Yy1 protein, mouse; C494700:Yy1 protein, rat