Regulation of sphingosine-1-phosphate lyase gene expression by members of the GATA family of transcription factors.
Sphingosine-1-phosphate is a bioactive sphingolipid that regulates proliferation, differentiation, migration, and apoptosis. Sphingosine-1-phosphate is irreversibly degraded by the highly conserved enzyme sphingosine-1-phosphate lyase. Recent studies have suggested that sphingosine-1-phosphate lyase expression affects animal development and cell fate decisions. Despite its crucial role, mechanisms affecting expression of sphingosine-1-phosphate lyase remain poorly understood. In this study, regulation of sphingosine-1-phosphate lyase gene expression was investigated in Caenorhabditis elegans, where lyase expression is spatially restricted to cells of the developing and adult gut and is essential for normal development. Deletion analysis and generation of transgenic worms combined with fluorescence microscopy identified a 350-nucleotide sequence upstream of the ATG start site necessary for maximal lyase expression in adult worms. Site-specific mutagenesis of a GATA transcription factor-binding motif in the promoter led to loss of reporter expression. Knockdown of the gut-specific GATA transcription factor ELT-2 by RNA interference similarly led to loss of reporter expression. ELT-2 interacted with the GATA factor-binding motif in vitro and was also capable of driving expression of a Caenorhabditis elegans lyase promoter-beta-galactosidase reporter in a heterologous yeast system. These studies demonstrate that ELT-2 regulates sphingosine-1-phosphate lyase expression in vivo. Additionally, we demonstrate that the human sphingosine-1-phosphate lyase gene is regulated by a GATA transcription factor. Overexpression of GATA-4 led to both an increase in activity of a reporter gene as well as an increase in endogenous sphingosine-1-phosphate lyase protein.
Oskouian
Babak
B
Children's Hospital Oakland Research Institute, Oakland, California 94609-1673 and California Institute of Technology, Division of Biology, Pasadena, California 91125, USA.
Mendel
Jane
J
Shocron
Ellyn
E
Lee
Michael A
MA
Fyrst
Henrik
H
Saba
Julie D
JD
D000446:Aldehyde-Lyases / Q000096:biosynthesis* / Q000235:genetics* / Q000378:metabolism; D000818:Animals; D017173:Caenorhabditis elegans / Q000201:enzymology / Q000235:genetics; D029742:Caenorhabditis elegans Proteins / Q000096:biosynthesis / Q000235:genetics; D002460:Cell Line; D004268:DNA-Binding Proteins / Q000096:biosynthesis / Q000235:genetics; D050980:GATA Transcription Factors; D050991:GATA4 Transcription Factor; D015971:Gene Expression Regulation, Enzymologic / Q000502:physiology*; D006801:Humans; D014157:Transcription Factors / Q000096:biosynthesis* / Q000235:genetics*
D029742:Caenorhabditis elegans Proteins; D004268:DNA-Binding Proteins; C094134:ELT-2 protein, C elegans; D050980:GATA Transcription Factors; D050991:GATA4 Transcription Factor; D014157:Transcription Factors; D000446:Aldehyde-Lyases; C022649:sphingosine 1-phosphate lyase (aldolase)