title: The Groucho ortholog UNC-37 interacts with the short Groucho-like protein LSY-22 to control developmental decisions in C. elegans.
abstract: Transcriptional co-repressors of the Groucho/TLE family are important regulators of development in many species. A subset of Groucho/TLE family members that lack the C-terminal WD40 domains have been proposed to act as dominant-negative regulators of Groucho/TLE proteins, yet such a role has not been conclusively proven. Through a mutant screen for genes controlling a left/right asymmetric cell fate decision in the nervous system of the nematode C. elegans, we have retrieved loss-of-function alleles in two distinct loci that display identical phenotypes in neuronal fate specification and in other developmental contexts. Using the novel technology of whole-genome sequencing, we find that these loci encode the C. elegans ortholog of Groucho, UNC-37, and, surprisingly, a short Groucho-like protein, LSY-22, that is similar to truncated Groucho proteins in other species. Besides their phenotypic similarities, unc-37 and lsy-22 show genetic interactions and UNC-37 and LSY-22 proteins also physically bind to each other in vivo. Our findings suggest that rather than acting as negative regulators of Groucho, small Groucho-like proteins may promote Groucho function. We propose that Groucho-mediated gene regulatory events involve heteromeric complexes of distinct Groucho-like proteins.
authors.affiliation: Department of Biochemistry and Molecular Biophysics, Howard Hughes Medical Institute, Columbia University Medical Center, Columbia University, New York, NY 10032, USA.
authors.forename: Eileen B
authors.initials: EB
authors.lastname: Flowers
authors.forename: Richard J
authors.initials: RJ
authors.lastname: Poole
authors.forename: Baris
authors.initials: B
authors.lastname: Tursun
authors.forename: Enkelejda
authors.initials: E
authors.lastname: Bashllari
authors.forename: Itsik
authors.initials: I
authors.lastname: Pe'er
authors.forename: Oliver
authors.initials: O
authors.lastname: Hobert
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D030801:Animals, Genetically Modified; D017173:Caenorhabditis elegans / Q000235:genetics / Q000254:growth & development* / Q000378:metabolism*; D029742:Caenorhabditis elegans Proteins / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism*; D004843:Epistasis, Genetic; D018507:Gene Expression Regulation, Developmental; D008954:Models, Biological; D008969:Molecular Sequence Data; D009154:Mutation; D055495:Neurogenesis / Q000235:genetics / Q000502:physiology; D012097:Repressor Proteins / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism*; D017386:Sequence Homology, Amino Acid; D014157:Transcription Factors / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism*; D020798:Two-Hybrid System Techniques
chemical_list: D029742:Caenorhabditis elegans Proteins; D012097:Repressor Proteins; D014157:Transcription Factors; C106184:unc-37 protein, C elegans