Protein interaction surface of the POU transcription factor UNC-86 selectively used in touch neurons.
The Caenorhabditis elegans POU protein UNC-86 specifies the HSN motor neurons, which are required for egg-laying, and six mechanosensory neurons. To investigate how UNC-86 controls neuronal specification, we characterized two unc-86 mutants that do not respond to touch but show wild-type egg-laying behavior. Residues P145 and L195, which are altered by these mutations, are located in the POU-specific domain and abolish the physical interaction of UNC-86 with the LIM homeodomain protein, MEC-3. This results in a failure to maintain mec-3 expression and in loss of expression of the mechanosensory neuron-specific gene, mec-2. unc-86-dependent expression of genes in other neurons is not impaired. We conclude that distinct residues in the POU domain of UNC-86 are involved in modulating UNC-86 activity during its specification of different neurons. A structural model of the UNC-86 POU domain, including base pairs and amino acid residues required for MEC-3 interaction, revealed that P145 and L195 are part of a hydrophobic pocket which is similar to the OCA-B-binding domain of the mammalian POU protein, Oct-1.
Röhrig
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Laboratorium für Molekulare Biologie-Genzentrum der Ludwig-Maximilians-Universität, München, Germany.
Röckelein
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Donhauser
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Baumeister
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D000595:Amino Acid Sequence; D019943:Amino Acid Substitution; D000818:Animals; D001665:Binding Sites; D017173:Caenorhabditis elegans / Q000196:embryology / Q000235:genetics / Q000378:metabolism*; D029742:Caenorhabditis elegans Proteins; D002454:Cell Differentiation; D019070:Cell Lineage; D018509:DNA, Helminth / Q000235:genetics / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000737:chemistry / Q000378:metabolism; D005260:Female; D018507:Gene Expression Regulation, Developmental; D015801:Helminth Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D018398:Homeodomain Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D051863:Host Cell Factor C1; D060850:LIM-Homeodomain Proteins; D008565:Membrane Proteins / Q000235:genetics / Q000378:metabolism; D008958:Models, Molecular; D008969:Molecular Sequence Data; D020125:Mutation, Missense; D009475:Neurons, Afferent / Q000378:metabolism*; D050811:Octamer Transcription Factor-1; D010058:Oviposition / Q000502:physiology; D050809:POU Domain Factors; D011401:Promoter Regions, Genetic / Q000235:genetics; D011485:Protein Binding; D017434:Protein Structure, Tertiary; D012441:Saccharomyces cerevisiae / Q000235:genetics; D014110:Touch / Q000502:physiology*; D014157:Transcription Factors / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*
D029742:Caenorhabditis elegans Proteins; D018509:DNA, Helminth; D004268:DNA-Binding Proteins; D015801:Helminth Proteins; D018398:Homeodomain Proteins; D051863:Host Cell Factor C1; D060850:LIM-Homeodomain Proteins; C096705:MEC-2 protein, C elegans; D008565:Membrane Proteins; D050811:Octamer Transcription Factor-1; D050809:POU Domain Factors; D014157:Transcription Factors; C497691:hcf-1 protein, C elegans; C072005:mec-3 protein, C elegans; C081539:unc-86 protein, C elegans