In vitro and in vivo characterization of Caenorhabditis elegans PHA-4/FoxA response elements.
Caenorhabditis elegans PHA-4 is a member of the FoxA group of transcription factors. PHA-4 is critical for development of the C. elegans pharynx and directly regulates most or all pharyngeal genes. The consensus binding site of PHA-4 has not been identified, with previous analysis of PHA-4 targets relying on the mammalian FoxA consensus. Here, we use in vitro and in vivo analyses to demonstrate three features of PHA-4 response elements. First, the PHA-4 consensus matches that of other FoxA proteins, but only a subset of possible sites is active in an in vivo assay. Second, sequence flanking the core PHA-4 site can influence the strength of reporter expression in vivo, as seen for other Fox proteins. Third, in the context of some pharyngeal promoters, PHA-4 response elements are flanked by distinct cis-regulatory elements that modulate response to PHA-4, generating gene expression in specific pharyngeal cell types.
Raharjo
Wahyu Hendrati
WH
Genes and Development Research Group, Department of Molecular Biology and Biochemistry, Department of Medical Genetics, Alberta Children's Hospital Research Institute, for Child and Maternal Health, University of Calgary, Calgary, Alberta, Canada.
Logan
Brittany C
BC
Wen
Shoubin
S
Kalb
John M
JM
Gaudet
Jeb
J
D000818:Animals; D017173:Caenorhabditis elegans / Q000235:genetics*; D029742:Caenorhabditis elegans Proteins / Q000235:genetics*; D018507:Gene Expression Regulation, Developmental; D017238:Genes, Helminth; D010614:Pharynx; D012045:Regulatory Sequences, Nucleic Acid; D020218:Response Elements; D015534:Trans-Activators / Q000235:genetics*
D029742:Caenorhabditis elegans Proteins; C113277:Pha-4 protein, C elegans; D015534:Trans-Activators