title: Conserved SAMS function in regulating egg-laying in C. elegans.
abstract: S-adenosyl-L-methionine (SAM) is an intermediate metabolite of methionine and serves as the methyl donor for many biological methylation reactions. The synthesis of SAM is catalyzed by SAM synthetase (SAMS), which transfers the adenosyl moiety of adenosine-5'-triphosphate to methionine. In the nematode Caenorhabditis elegans, four sams family genes, sams-1, -3, -4 and -5, are predicted to encode SAMS proteins. However, their physiological roles remain unclear. Here we show that the four predicted SAMS proteins in fact have the ability to catalyze the formation of SAM in vitro, and revealed that only sams-1 mutant animals among the family genes exhibited a significant reduction in egg-laying. Using transgenic animals carrying a transcriptional reporter for each sams gene promoter, we observed that each sams promoter confers a distinct expression pattern with respect to tissue, time of expression and expression level (i.e. promoter specificity). Promoter-swap experiments revealed that the ectopic expression of SAMS-3, -4 or -5 driven by the sams-1 promoter completely rescued egg-laying in sams-1 mutants. These data indicate that SAMS protein function is conserved throughout the entire family.
authors: Life Science Center, Tsukuba Advanced Research Alliance, Graduate School of Life and Environmental Sciences, University of Tsukuba, 1-1-1 Tennoudai, Tsukuba, Ibaraki, Japan.
authors: Hiroko
authors: H
authors: Tamiya
authors: Keiko
authors: K
authors: Hirota
authors: Yuta
authors: Y
authors: Takahashi
authors: Hiroaki
authors: H
authors: Daitoku
authors: Yuta
authors: Y
authors: Kaneko
authors: Genki
authors: G
authors: Sakuta
authors: Kei
authors: K
authors: Iizuka
authors: Satoshi
authors: S
authors: Watanabe
authors: Naoaki
authors: N
authors: Ishii
authors: Akiyoshi
authors: A
authors: Fukamizu
mesh_terms: D000818:Animals; D030801:Animals, Genetically Modified / Q000502:physiology*; D017173:Caenorhabditis elegans / Q000502:physiology*; D005260:Female; D008715:Methionine / Q000378:metabolism*; D008716:Methionine Adenosyltransferase / Q000378:metabolism*; D010058:Oviposition / Q000502:physiology*
chemical_list: D008715:Methionine; D008716:Methionine Adenosyltransferase