title: Cloning and characterization of a hydroxycinnamoyl-CoA:tyramine N-(hydroxycinnamoyl)transferase induced in response to UV-C and wounding from Capsicum annuum.
abstract: Hydroxycinnamoyl-CoA : tyramine N-(hydroxycinnamoyl) transferase (THT) is a pivotal enzyme in the synthesis of N-(hydroxycinnamoyl)-amines, which are associated with cell wall fortification in plants. The cDNA encoding THT was cloned from the leaves of UV-C treated Capsicum annuum (hot pepper) using a differential screening strategy. The predicted protein encoded by the THT cDNA is 250 amino acids in length and has a relative molecular mass of 28,221. The protein sequence derived from the cDNA shares 76% and 67% identity with the potato and tobacco THT protein sequences, respectively. The recombinant pepper THT enzyme was purified using a bacterial overexpression system. The purified enzyme has a broad substrate specificity including acyl donors such as cinnamoyl-, sinapoyl-, feruloyl-, caffeoyl-, and 4-coumaroyl-CoA and acceptors such as tyramine and octopamine. In UV-C treated plants, the THT mRNA was strongly induced in leaves, and the elevated level of expression was stable for up to 36 h. THT mRNA also increased in leaves that were detached from the plant but not treated with UV-C. THT expression was measured in different plant tissues, and was constitutive at a similar level in leaf, root, stem, flower and fruit. Induction of THT mRNA was correlated with an increase in THT protein.
authors.affiliation: Department of Genetic Engineering, Biotechnology Research Institute, Chonnam National University, Kwangju, 500-757 South Korea. kback@chonnam.ac.kr
authors.forename: K
authors.initials: K
authors.lastname: Back
authors.forename: S M
authors.initials: SM
authors.lastname: Jang
authors.forename: B C
authors.initials: BC
authors.lastname: Lee
authors.forename: A
authors.initials: A
authors.lastname: Schmidt
authors.forename: D
authors.initials: D
authors.lastname: Strack
authors.forename: K M
authors.initials: KM
authors.lastname: Kim
mesh_terms: D000217:Acyltransferases / Q000096:biosynthesis / Q000235:genetics / Q000378:metabolism*; D000595:Amino Acid Sequence; D001483:Base Sequence; D002212:Capsicum / Q000201:enzymology* / Q000235:genetics; D003001:Cloning, Molecular; D003373:Coumaric Acids; D018076:DNA, Complementary / Q000737:chemistry / Q000302:isolation & purification; D018744:DNA, Plant; D004790:Enzyme Induction; D004926:Escherichia coli; D015971:Gene Expression Regulation, Enzymologic / Q000528:radiation effects; D018506:Gene Expression Regulation, Plant / Q000528:radiation effects; D007700:Kinetics; D008969:Molecular Sequence Data; D009655:Octopamine / Q000737:chemistry / Q000378:metabolism; D014466:Ultraviolet Rays
chemical_list: D003373:Coumaric Acids; D018076:DNA, Complementary; D018744:DNA, Plant; C001411:N-(4-hydroxy-beta-phenethyl)-4-hydroxycinnamide; D009655:Octopamine; D000217:Acyltransferases; C108168:hydroxycinnamoyl-CoA-tyramine N-(hydroxycinnamoyl)transferase