start-ver=1.4 cd-journal=joma no-vol=379 cd-vols= no-issue=2 article-no= start-page= end-page= dt-received= dt-revised= dt-accepted= dt-pub-year=2008 dt-pub=20080514 dt-online= en-article= kn-article= en-subject= kn-subject= en-title= kn-title=Transcription Factors GATA/ELT-2 and Forkhead/HNF-3/PHA-4 Regulate the Tropomyosin Gene Expression in the Pharynx and Intestine of Caenorhabditis elegans en-subtitle= kn-subtitle= en-abstract= kn-abstract=

Gene regulation during development is an important biological activity that leads to synthesis of biomolecules at specific locations and specific times. The single tropomyosin gene of Caenorhabditis elegans, tmy-1/lev-11 produces four isoforms of protein: two from the external promoter and two from the internal promoter. We investigated the internal promoter of tropomyosin to identify sequences that regulate expression of tmy-1 in the pharynx and intestine. By promoter deletion of tmy-1 reporters as well as by database analyses, a 100 bp fragment was identified that contained binding sequences for a GATA factor, for a chicken CdxA homolog and for a forkhead factor. Both the forkhead and CdxA binding sequences contributed to pharyngeal and intestinal expression. In addition, the GATA site also influenced intestinal expression of tmy-1 reporter. We showed that ELT-2 and PHA-4 proteins interact directly with the GATA and forkhead binding sequences, respectively, in gel mobility shift assays. RNAi knockdown of elt-2 diminished tmy-1::gfp expression in the intestine. In contrast to RNAi knockdown of pha-4, expression of tmy-1::gfp in pha-4;smg-1 mutants was slightly weaker to that of the wild type. Ectopic expression of PHA-4 and ELT-2 by heat shock were sufficient to elicit widespread expression of tmy- 1::lacZ reporter in embryos. We found no indication of a synergistic relation between ELT-2 and PHA-4. Based on our data, PHA-4 and CdxA function as general transcription factors for pharyngeal and intestinal regulation of tmy-1. We present models by which ELT-2, PHA-4 and CdxA orchestrate expression from the internal promoter of tmy-1.

en-copyright= kn-copyright= en-aut-name=Anokye-DansoFrederick en-aut-sei=Anokye-Danso en-aut-mei=Frederick kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=1 ORCID= en-aut-name=AnyanfulAkwasi en-aut-sei=Anyanful en-aut-mei=Akwasi kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=2 ORCID= en-aut-name=SakubeYasuji en-aut-sei=Sakube en-aut-mei=Yasuji kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=3 ORCID= en-aut-name=KagawaHiroaki en-aut-sei=Kagawa en-aut-mei=Hiroaki kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=4 ORCID= affil-num=1 en-affil= kn-affil=Okayama University affil-num=2 en-affil= kn-affil=Okayama University affil-num=3 en-affil= kn-affil=Okayama University affil-num=4 en-affil= kn-affil=Okayama University en-keyword=Caenorhabditis elegans kn-keyword=Caenorhabditis elegans en-keyword=tropomyosin kn-keyword=tropomyosin en-keyword=HNF-3/PHA-4 kn-keyword=HNF-3/PHA-4 en-keyword=GATA/ELT-2 kn-keyword=GATA/ELT-2 en-keyword=transcription kn-keyword=transcription END