Ras/mitogen-activated protein kinase signaling activates Ets-1 and Ets-2 by CBP/p300 recruitment.
Cell signaling affects gene expression by regulating the activity of transcription factors. Here, we report that mitogen-activated protein kinase (MAPK) phosphorylation of Ets-1 and Ets-2, at a conserved site N terminal to their Pointed (PNT) domains, resulted in enhanced transactivation by preferential recruitment of the coactivators CREB binding protein (CBP) and p300. We discovered this phosphorylation-augmented interaction in an unbiased affinity chromatography screen of HeLa nuclear extracts by using either mock-treated or ERK2-phosphorylated ETS proteins as ligands. Binding between purified proteins demonstrated a direct interaction. Both the phosphoacceptor site, which lies in an unstructured region, and the PNT domain were required for the interaction. Minimal regions that were competent for induced CBP/p300 binding in vitro also supported MAPK-enhanced transcription in vivo. CBP coexpression potentiated MEK1-stimulated Ets-2 transactivation of promoters with Ras-responsive elements. Furthermore, CBP and Ets-2 interacted in a phosphorylation-enhanced manner in vivo. This study describes a distinctive interface for a transcription factor-coactivator complex and demonstrates a functional role for inducible CBP/p300 binding. In addition, our findings decipher the mechanistic link between Ras/MAPK signaling and two specific transcription factors that are relevant to both normal development and tumorigenesis.
Foulds
Charles E
CE
Huntsman Cancer Institute, 2000 Circle of Hope, University of Utah, Salt Lake City, UT 84112-5550, USA.
Nelson
Mary L
ML
Blaszczak
Adam G
AG
Graves
Barbara J
BJ
D000123:Acetyltransferases / Q000378:metabolism; D000595:Amino Acid Sequence; D016367:Baculoviridae / Q000235:genetics; D015153:Blotting, Western; D050882:CREB-Binding Protein; D018797:Cell Cycle Proteins / Q000378:metabolism; D002846:Chromatography, Affinity; D017930:Genes, Reporter; D011905:Genes, ras; D006367:HeLa Cells; D051548:Histone Acetyltransferases; D006801:Humans; D008156:Luciferases / Q000378:metabolism; D020928:Mitogen-Activated Protein Kinases / Q000378:metabolism*; D008954:Models, Biological; D008958:Models, Molecular; D019906:Nuclear Magnetic Resonance, Biomolecular; D009687:Nuclear Proteins / Q000378:metabolism*; D010766:Phosphorylation; D017434:Protein Structure, Tertiary; D050784:Proto-Oncogene Protein c-ets-1; D050787:Proto-Oncogene Protein c-ets-2; D011518:Proto-Oncogene Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D050783:Proto-Oncogene Proteins c-ets; D011994:Recombinant Proteins / Q000378:metabolism; D015398:Signal Transduction; D016622:Silver Staining; D015534:Trans-Activators / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D014157:Transcription Factors / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D015533:Transcriptional Activation; D050880:p300-CBP Transcription Factors; D000099224:p300-CBP-Associated Factor
D000123:Acetyltransferases; D050882:CREB-Binding Protein; D018797:Cell Cycle Proteins; D051548:Histone Acetyltransferases; D008156:Luciferases; D020928:Mitogen-Activated Protein Kinases; D009687:Nuclear Proteins; D050784:Proto-Oncogene Protein c-ets-1; D050787:Proto-Oncogene Protein c-ets-2; D011518:Proto-Oncogene Proteins; D050783:Proto-Oncogene Proteins c-ets; D011994:Recombinant Proteins; D015534:Trans-Activators; D014157:Transcription Factors; D050880:p300-CBP Transcription Factors; D000099224:p300-CBP-Associated Factor; C494041:ETS1 protein, human; C494069:ETS2 protein, human; C494363:CREBBP protein, human