title: A Role for Autoinhibition in Preventing Dimerization of the Transcription Factor ETS1.
abstract: ETS1 is the archetype of the ETS transcription factor (TF) family. ETS TFs share a DNA-binding domain, the ETS domain. All ETS TFs recognize a core GGA(A/T) binding site, and thus ETS TFs are found to redundantly regulate the same genes. However, each ETS TF has unique targets as well. One prevailing hypotheses explaining this duality is that protein-protein interactions, including homodimerization, allow each ETS TF to display distinct behavior. The behavior of ETS1 is further regulated by autoinhibition. Autoinhibition apparently modulates ETS1 DNA binding affinity, but the mechanism of this inhibition is not completely understood. We sought to characterize the relationship between DNA binding and ETS1 homodimer formation. We find that ETS1 interrogates DNA and forms dimers even when the DNA does not contain an ETS recognition sequence. Mutational studies also link nonspecific DNA backbone contacts with dimer formation, in addition to providing a new role for the recognition helix of ETS1 in maintaining the autoinhibited state. Finally, in showing that residues in the DNA recognition helix affect autoinhibition, we define a new function of ETS1 autoinhibition: maintenance of a monomeric state in the absence of DNA. The conservation of relevant amino acid residues across all ETS TFs indicates that the mechanisms of nonspecific DNA interrogation and protein oligomer formation elucidated here may be common to all ETS proteins that autoinhibit.
authors.affiliation: From the Department of Biological Sciences, University at Buffalo, Buffalo, New York 14260.
authors.forename: Daniel
authors.initials: D
authors.lastname: Samorodnitsky
authors.affiliation: From the Department of Biological Sciences, University at Buffalo, Buffalo, New York 14260.
authors.forename: Courtney
authors.initials: C
authors.lastname: Szyjka
authors.affiliation: From the Department of Biological Sciences, University at Buffalo, Buffalo, New York 14260 koudelka@buffalo.edu.
authors.forename: Gerald B
authors.initials: GB
authors.lastname: Koudelka
mesh_terms: D001665:Binding Sites / Q000235:genetics; D001667:Binding, Competitive; D002942:Circular Dichroism; D004247:DNA / Q000737:chemistry* / Q000378:metabolism; D018983:DNA Footprinting / Q000379:methods; D003850:Deoxyribonuclease I / Q000378:metabolism; D006801:Humans; D050505:Mutant Proteins / Q000737:chemistry / Q000378:metabolism; D009154:Mutation; D009841:Oligonucleotides / Q000737:chemistry / Q000378:metabolism; D011485:Protein Binding; D055503:Protein Multimerization; D050784:Proto-Oncogene Protein c-ets-1 / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D014157:Transcription Factors / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism
chemical_list: C494041:ETS1 protein, human; D050505:Mutant Proteins; D009841:Oligonucleotides; D050784:Proto-Oncogene Protein c-ets-1; D014157:Transcription Factors; D004247:DNA; D003850:Deoxyribonuclease I
keywords: DNA binding protein; DNA-protein interaction; ETS transcription factor family; autoinhibition; circular dichroism (CD); dimerization; protein conformation; protein cross-linking; protein-nucleic acid interaction