The UNC-3 Olf/EBF protein represses alternate neuronal programs to specify chemosensory neuron identity

• Published in: Developmental biology 2005-10, Vol.286 (1), p.136-148
• Main Authors: Kim, Kyuhyung, Colosimo, Marc E., Yeung, Helen, Sengupta, Piali
• Format: Article
• Language: English
• Subjects: Animals; Animals, Genetically Modified; ASI; Base Sequence; Binding Sites - genetics; Caenorhabditis elegans; Caenorhabditis elegans - cytology; Caenorhabditis elegans - genetics; Caenorhabditis elegans - growth & development; Caenorhabditis elegans - metabolism; Caenorhabditis elegans Proteins - genetics; Caenorhabditis elegans Proteins - metabolism; Chemoreceptor Cells - metabolism; Chemosensory neuron; DNA, Helminth - genetics; DNA, Helminth - metabolism; Gene Expression Regulation, Developmental; Genes, Helminth; Mutation; Olf/EBF; Promoter Regions, Genetic; Transcription Factors - genetics; Transcription Factors - metabolism; unc-3
• ISSN: 0012-1606; 1095-564X
• DOI: 10.1016/j.ydbio.2005.07.024

Neuronal identities are specified by the combinatorial functions of activators and repressors of gene expression. Members of the well-conserved Olf/EBF (O/E) transcription factor family have been shown to play important roles in neuronal and non-neuronal development and differentiation. O/E proteins are highly expressed in the olfactory epithelium, and O/E binding sites have been identified upstream of olfactory genes. However, the roles of O/E proteins in sensory neuron development are unclear. Here we show that the O/E protein UNC-3 is required for subtype specification of the ASI chemosensory neurons in Caenorhabditis elegans. UNC-3 promotes an ASI identity by directly repressing the expression of alternate neuronal programs and by activating expression of ASI-specific genes including the daf-7 TGF-β gene. Our results indicate that UNC-3 is a critical component of the transcription factor code that integrates cell-intrinsic developmental programs with external signals to specify sensory neuronal identity and suggest models for O/E protein functions in other systems.