title: Clone and functional analysis of Seryl-tRNA synthetase and Tyrosyl-tRNA synthetase from silkworm, Bombyx mori.
abstract: Aminoacyl-tRNA synthetases are the key enzymes for protein synthesis. Glycine, alanine, serine and tyrosine are the major amino acids composing fibroin of silkworm. Among them, the genes of alanyl-tRNA synthetase (AlaRS) and glycyl-tRNA synthetase (GlyRS) have been cloned. In this study, the seryl-tRNA synthetase (SerRS) and tyrosyl-tRNA synthetase (TyrRS) genes from silkworm were cloned. Their full length are 1709 bp and 1868 bp and contain open reading frame (ORF) of 1485 bp and 1575 bp, respectively. RT-PCR examination showed that the transcription levels of SerRS, TyrRS, AlaRS and GlyRS are significantly higher in silk gland than in other tissues. In addition, their transcription levels are much higher in middle and posterior silk gland than in anterior silk gland. Moreover, treatment of silkworms with phoxim, an inhibitor of silk protein synthesis, but not TiO2NP, an enhancer of silk protein synthesis, significantly reduced the transcription levels of aaRS and content of free amino acids in posterior silk gland, therefore affecting silk protein synthesis, which may be the mechanism of phoxim-silking disorders. Furthermore, low concentration of TiO2NPs showed no effect on the transcription of aaRS and content of free amino acids, suggesting that TiO2NPs promotes silk protein synthesis possibly by increasing the activity of fibroin synthase in silkworm.
authors.affiliation: School of Basic Medicine and Biological Sciences, Soochow University, Suzhou, Jiangsu 215123, P.R. China.
authors.forename: Jingsheng
authors.initials: J
authors.lastname: Hu
authors.affiliation: School of Basic Medicine and Biological Sciences, Soochow University, Suzhou, Jiangsu 215123, P.R. China.
authors.forename: Jianghai
authors.initials: J
authors.lastname: Tian
authors.affiliation: School of Basic Medicine and Biological Sciences, Soochow University, Suzhou, Jiangsu 215123, P.R. China.
authors.forename: Fanchi
authors.initials: F
authors.lastname: Li
authors.affiliation: School of Basic Medicine and Biological Sciences, Soochow University, Suzhou, Jiangsu 215123, P.R. China.
authors.forename: Bin
authors.initials: B
authors.lastname: Xue
authors.affiliation: School of Basic Medicine and Biological Sciences, Soochow University, Suzhou, Jiangsu 215123, P.R. China.
authors.forename: Jiahuan
authors.initials: J
authors.lastname: Hu
authors.affiliation: School of Basic Medicine and Biological Sciences, Soochow University, Suzhou, Jiangsu 215123, P.R. China.
authors.forename: Xiaoyu
authors.initials: X
authors.lastname: Cheng
authors.affiliation: School of Basic Medicine and Biological Sciences, Soochow University, Suzhou, Jiangsu 215123, P.R. China.
authors.forename: Jinxin
authors.initials: J
authors.lastname: Li
authors.affiliation: School of Basic Medicine and Biological Sciences, Soochow University, Suzhou, Jiangsu 215123, P.R. China.|National Engineering Laboratory for Modern Silk, Soochow University, Suzhou, Jiangsu 215123, P.R. China.
authors.forename: Weide
authors.initials: W
authors.lastname: Shen
authors.affiliation: School of Basic Medicine and Biological Sciences, Soochow University, Suzhou, Jiangsu 215123, P.R. China.|National Engineering Laboratory for Modern Silk, Soochow University, Suzhou, Jiangsu 215123, P.R. China.
authors.forename: Bing
authors.initials: B
authors.lastname: Li
mesh_terms: D000595:Amino Acid Sequence; D000596:Amino Acids / Q000378:metabolism; D000818:Animals; D012831:Bombyx / Q000145:classification / Q000201:enzymology* / Q000235:genetics*; D003001:Cloning, Molecular; D018076:DNA, Complementary; D019143:Evolution, Molecular; D015870:Gene Expression; D053768:Metal Nanoparticles / Q000737:chemistry; D016366:Open Reading Frames; D010802:Phylogeny; D012714:Serine-tRNA Ligase / Q000235:genetics* / Q000378:metabolism*; D014025:Titanium / Q000737:chemistry / Q000494:pharmacology; D014448:Tyrosine-tRNA Ligase / Q000235:genetics* / Q000378:metabolism*
chemical_list: D000596:Amino Acids; D018076:DNA, Complementary; C009495:titanium dioxide; D014025:Titanium; D014448:Tyrosine-tRNA Ligase; D012714:Serine-tRNA Ligase