title: Molecular cloning, characterization, and expression analysis of a novel gene encoding L-cysteine desulfhydrase from Brassica napus.
abstract: L-Cysteine desulfhydrase (DES; EC 4.4.1.1) is the most important enzyme that catalyzes the decomposition of L-cysteine to pyruvate, ammonia, and hydrogen sulfide (H2S), the latter of which has recently been recognized as the third gasotransmitter for multiple signaling events in plants. Previous results showed the existence of DES activity in Brassica napus; however, the gene encoding the true DES protein has not been characterized yet. Here, a rapeseed DES gene was isolated and sequenced. It shared high homology with Arabidopsis DES1, and encodes a polypeptide with 323 amino acids of 34.5 kDa. Subsequently, prokaryotic expression and biochemical analysis demonstrated that this protein predominantly catalyzes the breakdown of L-cysteine with the side reaction of L-cysteine synthesis [O-acetyl-L-serine(thiol)lyase activity], and was designated as BnDES1. Corresponding analysis of structural features was also in agreement with the above proposition. Molecular evidence showed that BnDES1 mRNA was widely expressed, but with the higher expression level in flowers. Further results showed that the BnDES1 transcripts were differentially up-regulated by several plant growth regulators and chemicals. Overall, the above findings provide evidence showing that BnDES1 is a potentially important enzyme responsible for the H2S production, and may play an important role in plant growth regulators and chemical stimuli responses.
authors.affiliation: College of Life Sciences, Nanjing Agricultural University, Nanjing 210095, People's Republic of China.
authors.forename: Yanjie
authors.initials: Y
authors.lastname: Xie
authors.forename: Diwen
authors.initials: D
authors.lastname: Lai
authors.forename: Yu
authors.initials: Y
authors.lastname: Mao
authors.forename: Wei
authors.initials: W
authors.lastname: Zhang
authors.forename: Wenbiao
authors.initials: W
authors.lastname: Shen
authors.forename: Rongzhan
authors.initials: R
authors.lastname: Guan
mesh_terms: D000595:Amino Acid Sequence; D001709:Biotechnology; D001937:Brassica / Q000201:enzymology* / Q000235:genetics*; D003001:Cloning, Molecular; D003542:Cystathionine gamma-Lyase / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D004926:Escherichia coli / Q000201:enzymology / Q000235:genetics; D018506:Gene Expression Regulation, Plant / Q000187:drug effects; D008969:Molecular Sequence Data; D009928:Organ Specificity; D010802:Phylogeny; D010937:Plant Growth Regulators / Q000494:pharmacology; D010940:Plant Proteins / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D011994:Recombinant Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D016415:Sequence Alignment
chemical_list: D010937:Plant Growth Regulators; D010940:Plant Proteins; D011994:Recombinant Proteins; D003542:Cystathionine gamma-Lyase