A functional interaction between ATF7 and TAF12 that is modulated by TAF4.
The ATF7 proteins, which are members of the cyclic AMP responsive binding protein (CREB)/activating transcription factor (ATF) family of transcription factors, display quite versatile properties: they can interact with the adenovirus E1a oncoprotein, mediating part of its transcriptional activity; they heterodimerize with the Jun, Fos or related transcription factors, likely modulating their DNA-binding specificity; they also recruit to the promoter a stress-induced protein kinase (JNK2). In the present study, we investigate the functional relationships of ATF7 with hsTAF12 (formerly hsTAF(II)20/15), which has originally been identified as a component of the general transcription factor TFIID. We show that overexpression of hsTAF12 potentiates ATF7-induced transcriptional activation through direct interaction with ATF7, suggesting that TAF12 is a functional partner of ATF7. In support of this conclusion, chromatin immunoprecipitation experiments confirm the interaction of ATF7 with TAF12 on an ATF7-responsive promoter, in the absence of any artificial overexpression of both proteins. We also show that the TAF12-dependent transcriptional activation is competitively inhibited by TAF4. Although both TAF12 isoforms (TAF12-1 and -2, formerly TAF(II)20 and TAF(II)15) interact with the ATF7 activation region through their histone-fold domain, only the largest, hsTAF12-1, mediates transcriptional activation through its N-terminal region.
Hamard
Pierre-Jacques
PJ
Ecole Supérieure de Biotechnologie de Strasbourg, Université Louis Pasteur, Parc d'innovation, UMR7100 CNRS-ULP, Bd. Sebastien Brant-BP10413, 67412 Strasbourg, Illkirch Cedex, France.
Dalbies-Tran
Rozenn
R
Hauss
Charlotte
C
Davidson
Irwin
I
Kedinger
Claude
C
Chatton
Bruno
B
D051696:Activating Transcription Factors; D000595:Amino Acid Sequence; D000818:Animals; D002460:Cell Line; D002843:Chromatin; D004268:DNA-Binding Proteins / Q000096:biosynthesis / Q000494:pharmacology*; D005786:Gene Expression Regulation; D006801:Humans; D047468:Immunoprecipitation; D007313:Insecta; D016350:Leucine Zippers; D008969:Molecular Sequence Data; D020411:Oligonucleotide Array Sequence Analysis; D020133:Reverse Transcriptase Polymerase Chain Reaction; D035381:TATA-Binding Protein Associated Factors / Q000096:biosynthesis* / Q000494:pharmacology*; D035362:Transcription Factor TFIID / Q000494:pharmacology*; D014157:Transcription Factors / Q000096:biosynthesis / Q000494:pharmacology*; D014158:Transcription, Genetic
C427752:ATF7 protein, human; D051696:Activating Transcription Factors; D002843:Chromatin; D004268:DNA-Binding Proteins; C470012:TAF12 protein, human; C101882:TAF4 protein, human; D035381:TATA-Binding Protein Associated Factors; D035362:Transcription Factor TFIID; D014157:Transcription Factors