Promoter sequences for the establishment of mec-3 expression in the nematode Caenorhabditis elegans.
In certain stereotyped lineages of Caenorhabditis elegans, the mec-3 gene is transcribed in neurons that are anterior daughters of cells containing the UNC-86 protein. UNC-86 binds to the mec-3 promoter and is necessary for transcription activation, but this protein is present in many cells that do not transcribe mec-3, including the posterior sister and parent cells of the mec-3 expressing neurons. To understand how the mec-3 promoter directs transcription in only a subset of cells that contain UNC-86, we have compared sequences within the promoter that are bound by UNC-86 in vitro with sequences that are necessary for early transcription of mec-3 in vivo. We find that upstream of the mec-3 start codon are two blocks of sequence that are each sufficient to generate the cellular pattern of mec-3 transcription. The proximal sequence includes three previously identified short regions that have been conserved in nematode evolution and each contains one high-affinity UNC-86 binding site. The recognition consensus sequence for UNC-86 is CATnnnT/AAAT, which is identical to the recognition sequence for the UNC-86-related mammalian transcription factor Brn-3. Adjacent to the UNC-86 recognition site is an additional sequence that is important for establishment of mec-3 expression and is presumably recognized by an unidentified transcription factor.
Wang
L
L
Department of Biology, Nelson Laboratories, Rutgers University, Piscataway, NJ 08855, USA.
Way
J C
JC
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D017173:Caenorhabditis elegans / Q000196:embryology / Q000235:genetics*; D029742:Caenorhabditis elegans Proteins; D019070:Cell Lineage; D004268:DNA-Binding Proteins / Q000737:chemistry; D018507:Gene Expression Regulation, Developmental; D015801:Helminth Proteins / Q000096:biosynthesis / Q000235:genetics*; D018398:Homeodomain Proteins / Q000737:chemistry / Q000502:physiology; D060850:LIM-Homeodomain Proteins; D008969:Molecular Sequence Data; D009419:Nerve Tissue Proteins / Q000096:biosynthesis / Q000235:genetics*; D050809:POU Domain Factors; D011401:Promoter Regions, Genetic; D011993:Recombinant Fusion Proteins / Q000096:biosynthesis; D012045:Regulatory Sequences, Nucleic Acid; D016415:Sequence Alignment; D017384:Sequence Deletion; D017386:Sequence Homology, Amino Acid; D050818:Transcription Factor Brn-3; D014157:Transcription Factors / Q000737:chemistry / Q000502:physiology
D029742:Caenorhabditis elegans Proteins; D004268:DNA-Binding Proteins; D015801:Helminth Proteins; D018398:Homeodomain Proteins; D060850:LIM-Homeodomain Proteins; D009419:Nerve Tissue Proteins; D050809:POU Domain Factors; D011993:Recombinant Fusion Proteins; D050818:Transcription Factor Brn-3; D014157:Transcription Factors; C072005:mec-3 protein, C elegans; C081539:unc-86 protein, C elegans