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A Conserved α-Helical Motif Mediates the Binding of Diverse Nuclear Proteins to the SRC1 Interaction Domain of CBP
- Source :
- Journal of Biological Chemistry. 279:14055-14064
- Publication Year :
- 2004
- Publisher :
- Elsevier BV, 2004.
-
Abstract
- CREB-binding protein (CBP) and p300 contain modular domains that mediate protein-protein interactions with a wide variety of nuclear factors. A C-terminal domain of CBP (referred to as the SID) is responsible for interaction with the alpha-helical AD1 domain of p160 coactivators such as the steroid receptor coactivator (SRC1), and also other transcriptional regulators such as E1A, Ets-2, IRF3, and p53. Here we show that the pointed (PNT) domain of Ets-2 mediates its interaction with the CBP SID, and describe the effects of mutations in the SID on binding of Ets-2, E1A, and SRC1. In vitro binding studies indicate that SRC1, Ets-2 and E1A display mutually exclusive binding to the CBP SID. Consistent with this, we observed negative cross-talk between ERalpha/SRC1, Ets-2, and E1A proteins in reporter assays in transiently transfected cells. Transcriptional inhibition of Ets-2 or GAL4-AD1 activity by E1A was rescued by co-transfection with a CBP expression plasmid, consistent with the hypothesis that the observed inhibition was due to competition for CBP in vivo. Sequence comparisons revealed that SID-binding proteins contain a leucine-rich motif similar to the alpha-helix Aalpha1 of the SRC1 AD1 domain. Deletion mutants of E1A and Ets-2 lacking the conserved motif were unable to bind the CBP SID. Moreover, a peptide corresponding to this sequence competed the binding of full-length SRC1, Ets-2, and E1A proteins to the CBP SID. Thus, a leucine-rich amphipathic alpha-helix mediates mutually exclusive interactions of functionally diverse nuclear proteins with CBP.
- Subjects :
- Transcriptional Activation
viruses
Molecular Sequence Data
Peptide
In Vitro Techniques
Biology
Kidney
Binding, Competitive
Biochemistry
Protein Structure, Secondary
Proto-Oncogene Protein c-ets-2
Mice
Nuclear Receptor Coactivator 1
Proto-Oncogene Proteins
Two-Hybrid System Techniques
Coactivator
Animals
Humans
Amino Acid Sequence
Nuclear protein
Receptor
Molecular Biology
Conserved Sequence
Histone Acetyltransferases
chemistry.chemical_classification
Expression vector
Nuclear Proteins
Cell Biology
Transfection
CREB-Binding Protein
Molecular biology
Protein Structure, Tertiary
Cell biology
DNA-Binding Proteins
Repressor Proteins
Nuclear receptor coactivator 1
Amino Acid Substitution
chemistry
COS Cells
Trans-Activators
Adenovirus E1A Proteins
IRF3
Transcription Factors
Subjects
Details
- ISSN :
- 00219258
- Volume :
- 279
- Database :
- OpenAIRE
- Journal :
- Journal of Biological Chemistry
- Accession number :
- edsair.doi.dedup.....c0717951e10e28dd6bede20a2c4092ea