title: Distinct regulatory elements mediate similar expression patterns in the excretory cell of Caenorhabditis elegans.
abstract: Identification of cis-regulatory elements and their binding proteins constitutes an important part of understanding gene function and regulation. It is well accepted that co-expressed genes tend to share transcriptional elements. However, recent findings indicate that co-expression data show poor correlation with co-regulation data even in unicellular yeast. This motivates us to experimentally explore whether it is possible that co-expressed genes are subject to differential regulatory control using the excretory cell of Caenorhabditis elegans as an example. Excretory cell is a functional equivalent of human kidney. Transcriptional regulation of gene expression in the cell is largely unknown. We isolated a 10-bp excretory cell-specific cis-element, Ex-1, from a pgp-12 promoter. The significance of the element has been demonstrated by its capacity of converting an intestine-specific promoter into an excretory cell-specific one. We also isolated a cDNA encoding an Ex-1 binding transcription factor, DCP-66, using a yeast one-hybrid screen. Role of the factor in regulation of pgp-12 expression has been demonstrated both in vitro and in vivo. Search for occurrence of Ex-1 reveals that only a small portion of excretory cell-specific promoters contain Ex-1. Two other distinct cis-elements isolated from two different promoters can also dictate the excretory cell-specific expression but are independent of regulation by DCP-66. The results indicate that distinct regulatory elements are able to mediate the similar expression patterns.
authors.affiliation: Department of Genome Science, University of Washington, Seattle, Washington 98195-7730, USA. zhao@gs.washington.edu
authors.forename: Zhongying
authors.initials: Z
authors.lastname: Zhao
authors.forename: Li
authors.initials: L
authors.lastname: Fang
authors.forename: Nansheng
authors.initials: N
authors.lastname: Chen
authors.forename: Robert C
authors.initials: RC
authors.lastname: Johnsen
authors.forename: Lincoln
authors.initials: L
authors.lastname: Stein
authors.forename: David L
authors.initials: DL
authors.lastname: Baillie
mesh_terms: D018435:ATP Binding Cassette Transporter, Subfamily B / Q000235:genetics*; D000818:Animals; D001483:Base Sequence; D017173:Caenorhabditis elegans; D029742:Caenorhabditis elegans Proteins / Q000737:chemistry* / Q000235:genetics; D019295:Computational Biology; D004247:DNA / Q000737:chemistry / Q000378:metabolism; D018076:DNA, Complementary / Q000378:metabolism; D017353:Gene Deletion; D005786:Gene Expression Regulation; D017930:Genes, Reporter; D005838:Genotype; D049452:Green Fluorescent Proteins / Q000378:metabolism; D008954:Models, Biological; D008969:Molecular Sequence Data; D016297:Mutagenesis, Site-Directed; D011401:Promoter Regions, Genetic; D011485:Protein Binding; D017434:Protein Structure, Tertiary; D034622:RNA Interference; D014157:Transcription Factors / Q000235:genetics*; D014158:Transcription, Genetic; D019076:Transgenes; D020798:Two-Hybrid System Techniques
chemical_list: D018435:ATP Binding Cassette Transporter, Subfamily B; D029742:Caenorhabditis elegans Proteins; C506782:DCP-66 protein, C elegans; D018076:DNA, Complementary; C506781:Pgp-12 protein, C elegans; D014157:Transcription Factors; D049452:Green Fluorescent Proteins; D004247:DNA