title: EOR-2 is an obligate binding partner of the BTB-zinc finger protein EOR-1 in Caenorhabditis elegans.
abstract: BTB-zinc finger transcription factors play many important roles in metazoan development. In these proteins, the BTB domain is critical for dimerization and for recruiting cofactors to target genes. Identification of these cofactors is important for understanding how BTB-zinc finger proteins influence transcription. Here we show that the novel but conserved protein EOR-2 is an obligate binding partner of the BTB-zinc finger protein EOR-1 in Caenorhabditis elegans. EOR-1 and EOR-2 function together to promote multiple Ras/ERK-dependent cell fates during development, and we show that EOR-1 is a robust substrate of ERK in vitro. A point mutation (L81F) in the EOR-1 BTB domain reduces both ERK phosphorylation and EOR-2 binding and eliminates all detectable biological function without affecting EOR-1 expression levels, localization, or dimerization. This point mutation lies near the predicted charged pocket region of the EOR-1 BTB dimer, a region that, in other BTB-zinc finger proteins, has been proposed to interact with corepressors or coactivators. We also show that a conserved zinc finger-like motif in EOR-2 is required for binding to EOR-1, that the interaction between EOR-1 and EOR-2 is direct, and that EOR-2 can bind to the human BTB-zinc finger protein PLZF. We propose that EOR-2 defines a new family of cofactors for BTB-zinc finger transcription factors that may have conserved roles in other organisms.
authors.affiliation: Department of Genetics, University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania 19104, USA.
authors.forename: Kelly
authors.initials: K
authors.lastname: Howell
authors.forename: Swathi
authors.initials: S
authors.lastname: Arur
authors.forename: Tim
authors.initials: T
authors.lastname: Schedl
authors.forename: Meera V
authors.initials: MV
authors.lastname: Sundaram
mesh_terms: D000483:Alleles; D000595:Amino Acid Sequence; D000818:Animals; D001665:Binding Sites; D017173:Caenorhabditis elegans / Q000378:metabolism*; D029742:Caenorhabditis elegans Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D017124:Conserved Sequence; D048049:Extracellular Signal-Regulated MAP Kinases / Q000378:metabolism; D006801:Humans; D020935:MAP Kinase Signaling System; D008969:Molecular Sequence Data; D009687:Nuclear Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D011485:Protein Binding; D017434:Protein Structure, Tertiary; D017384:Sequence Deletion; D016335:Zinc Fingers; D018631:ras Proteins / Q000378:metabolism
chemical_list: D029742:Caenorhabditis elegans Proteins; C463999:EOR-1 protein, C elegans; C464000:EOR-2 protein, C elegans; D009687:Nuclear Proteins; D048049:Extracellular Signal-Regulated MAP Kinases; D018631:ras Proteins