title: Identification and characterization of a pyridoxal 5'-phosphate phosphatase in the silkworm (Bombyx mori).
abstract: Vitamin B6comprises six interconvertible pyridine compounds, among which pyridoxal 5'-phosphate (PLP) is a coenzyme for over 140 enzymes. PLP is also a very reactive aldehyde. The most well established mechanism for maintaining low levels of free PLP is its dephosphorylation by phosphatases. A human PLP-specific phosphatase has been identified and characterized. However, very little is known about the phosphatase in other living organisms. In this study, a cDNA clone of putative PLP phosphatase was identified from B. mori and characterized. The cDNA encodes a polypeptide of 343 amino acid residues, and the recombinant enzyme purified from E. coli exhibited properties similar to that of human PLP phosphatase. B. mori has a single copy of the PLPP gene, which is located on 11th chromosome, spans a 5.7kb region and contains five exons and four introns. PLP phosphatase transcript was detected in every larva tissue except hemolymph, and was most highly represented in Malpighian tube. We further down-regulated the gene expression of the PLP phosphatase in 5th instar larvae with the RNA interference. However, no significant changes in the gene expression of PLP biosynthetic enzymes and composition of B6vitamers were detected as compared with the control.
authors.affiliation: School of Tea and Food Science & Technology, Anhui Agricultural University, Hefei 230036, People's Republic of China.
authors.forename: ShuoHao
authors.initials: S
authors.lastname: Huang
authors.affiliation: School of Tea and Food Science & Technology, Anhui Agricultural University, Hefei 230036, People's Republic of China.
authors.forename: CaiYun
authors.initials: C
authors.lastname: Han
authors.affiliation: School of Tea and Food Science & Technology, Anhui Agricultural University, Hefei 230036, People's Republic of China.
authors.forename: ZhenQiao
authors.initials: Z
authors.lastname: Ma
authors.affiliation: School of Tea and Food Science & Technology, Anhui Agricultural University, Hefei 230036, People's Republic of China.
authors.forename: Jie
authors.initials: J
authors.lastname: Zhou
authors.affiliation: School of Foreign Languages, Anhui Agricultural University, Hefei 230036, People's Republic of China. Electronic address: jianyun218@aliyun.com.
authors.forename: JianYun
authors.initials: J
authors.lastname: Zhang
authors.affiliation: School of Tea and Food Science & Technology, Anhui Agricultural University, Hefei 230036, People's Republic of China. Electronic address: lqhuang218@aliyun.com.
authors.forename: LongQuan
authors.initials: L
authors.lastname: Huang
mesh_terms: D000818:Animals; D055162:Biocatalysis; D012831:Bombyx / Q000166:cytology / Q000201:enzymology* / Q000235:genetics* / Q000378:metabolism; D002875:Chromosomes / Q000378:metabolism; D003001:Cloning, Molecular; D015536:Down-Regulation / Q000235:genetics; D023281:Genomics; D006801:Humans; D007814:Larva / Q000235:genetics; D010744:Phosphoric Monoester Hydrolases / Q000737:chemistry / Q000172:deficiency / Q000235:genetics* / Q000378:metabolism*; D021381:Protein Transport; D011732:Pyridoxal Phosphate / Q000378:metabolism; D034741:RNA, Small Interfering / Q000235:genetics
chemical_list: D034741:RNA, Small Interfering; D011732:Pyridoxal Phosphate; C027138:pyridoxine phosphate phosphatase; D010744:Phosphoric Monoester Hydrolases
keywords: Bombyx mori; Characterization; Identification; Pyridoxal 5′-phosphate phosphatase