TY - JOUR
T1 - Transcription Factors GATA/ELT-2 and Forkhead/HNF-3/PHA-4 Regulate the Tropomyosin Gene Expression in the Pharynx and Intestine of Caenorhabditis elegans
AU - Anokye-Danso, Frederick
AU - Anyanful, Akwasi
AU - Sakube, Yasuji
AU - Kagawa, Hiroaki
N1 - Funding Information:
We express our appreciation to J.D. McGhee (University of Calgary, Canada) for scientific comments, for language editing, and for providing elt-2, elt-7, and acn-1 plasmids. We thank J.D. Saba (Children's Hospital Oakland Research Institute, USA) for supplying ELT-2 expression plasmid. We are grateful to A. Fire (Stanford University, USA) for vectors and Y. Kohara (National Institute of Genetics, Japan) for pha-4 and elt-2 cDNAs. We also thank S.E. Mango (University of Utah, USA) for pha-4(zu225);smg-1(cc546ts) and smg-1(cc546ts) mutant worms. Some of the nematodes were provided by the Caenorhabditis Genetics Center, which is funded by the National Institutes of Health National Center for Research and Resources. F.A.-D. is supported by a fellowship grant from the Ministry of Education, Science, Sports, and Culture of Japan. This work was funded by grants from the Ministry of Education, Science, Sports, and Culture of Japan to H.K.
PY - 2008/5/29
Y1 - 2008/5/29
N2 - 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 that contained binding sequences for a GATA factor, for a chicken CdxA homolog, and for a forkhead factor was identified. 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. RNA interference knockdown of elt-2 diminished tmy-1{proportion}gfp expression in the intestine. In contrast to RNA interference knockdown of pha-4, expression of tmy-1{proportion}gfp in pha-4;smg-1 mutants was slightly weaker than that of the wild type. Ectopic expression of PHA-4 and ELT-2 by heat shock was sufficient to elicit widespread expression of tmy-1{proportion}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.
AB - 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 that contained binding sequences for a GATA factor, for a chicken CdxA homolog, and for a forkhead factor was identified. 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. RNA interference knockdown of elt-2 diminished tmy-1{proportion}gfp expression in the intestine. In contrast to RNA interference knockdown of pha-4, expression of tmy-1{proportion}gfp in pha-4;smg-1 mutants was slightly weaker than that of the wild type. Ectopic expression of PHA-4 and ELT-2 by heat shock was sufficient to elicit widespread expression of tmy-1{proportion}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.
KW - Caenorhabditis elegans
KW - GATA/ELT-2
KW - HNF-3/PHA-4
KW - transcription
KW - tropomyosin
UR - http://www.scopus.com/inward/record.url?scp=43049146145&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=43049146145&partnerID=8YFLogxK
U2 - 10.1016/j.jmb.2007.11.103
DO - 10.1016/j.jmb.2007.11.103
M3 - Article
C2 - 18448117
AN - SCOPUS:43049146145
SN - 0022-2836
VL - 379
SP - 201
EP - 211
JO - Journal of molecular biology
JF - Journal of molecular biology
IS - 2
ER -