Enzymatic features of serotonin biosynthetic enzymes and serotonin biosynthesis in plants

被引：46

作者：

Kang, Kiyoon ^{[1
]}

Kang, Sei ^{[1
]}

Lee, Kyungjin ^{[1
]}

Park, Munyoung ^{[1
]}

Back, Kyoungwhan ^{[1
]}

机构：

[1] Chonnam Natl Univ, Biotechnol Res Inst, Agr Plant Stress Res Ctr, Dept Mol Biotechnol, Gwangju, South Korea

来源：

PLANT SIGNALING & BEHAVIOR | 2008年 / 3卷 / 06期

关键词：

feruloylserotonin; serotonin; tryptamine; 5-hydroxylase; tryptophan; tryptophan biosynthesis; tryptophan decarboxylase;

D O I：

10.4161/psb.3.6.5401

中图分类号：

Q5 [生物化学]; Q7 [分子生物学];

学科分类号：

071010 ; 081704 ;

摘要：

Serotonin, a pineal hormone in mammals, is found in a wide range of plant species at detection levels from a few nanograms to a few milligrams, and has been implicated in several physiological roles, such as flowering, morphogenesis and adaptation to environmental changes. Serotonin synthesis requires two enzymes, tryptophan decarboxylase (TDC) and tryptamine 5-hydroxylase (T5H), with TDC serving as a rate-limiting step because of its high K-m in relation to the substrate tryptophan (690 mu M) and its undetectable expression level in control plants. However, T5H and downstream enzymes, such as serotonin N-hydroxycinnamoyl transferase (SHT), have low K-m values with corresponding substrates. This suggests that the biosynthesis of serotonin or serotonin-derived secondary metabolites is restricted to cellular stages when high tryptophan levels are present.

引用

页码：389 / 390

页数：2

共 16 条

[1] Anthranilate synthase from Ruta graveolens - Duplicated AS alpha genes encode tryptophan-sensitive and tryptophan-insensitive isoenzymes specific to amino acid and alkaloid biosynthesis [J].