School of Life Sciences, Sichuan University, 24 South Section 1, 1st Ring Road, Chengdu, 610065, People's Republic of China.
Mol Biol Rep. 2012 Apr;39(4):3443-52. doi: 10.1007/s11033-011-1116-4. Epub 2011 Jun 26.
A PAL gene designated as JcPAL1 was cloned from J. curcas L. The full-length is 2336 bp in size with one intron and two exons, encoding a polypeptide of 713 amino acids. Its 5'-upstream region is rich in putative cis-elements including not only PAL typical TATA box, L-box and transcriptional initiation site (TIS) but also light responding motifs. Expression pattern analysis indicated that JcPAL1 were expressed in all tissues, most highly in flowers. When Treated with ABA, GA3, high and low temperature, expression of JcPAL1 were induced. Recombinant JcPAL1 has a pH optimum at 8.7 and a temperature optimum at 60°C in 100 mM Tris-HCl buffer. The Km and Kcat values are 0.125 mM and 1.73 S(-1) for L: -phenylalanine, and 1.312 mM and 0.109 S(-1) for L: -tyrosine, respectively. These findings suggested that JcPAL1 might involve in the J. curcas responding to various stresses and L: -Phe should be its true physiological substrate. This study is essential prior to uncover whether and how the PAL initiated phenylpropanoid metabolic networks functioning in the defense responses of J. curcas.
从麻疯树（Jatropha curcas L.）中克隆出一个 PAL 基因，命名为 JcPAL1。其全长为 2336bp，包含一个内含子和两个外显子，编码一个 713 个氨基酸的多肽。其 5'上游区域富含假定的顺式作用元件，不仅包括 PAL 典型的 TATA 盒、L 盒和转录起始位点（TIS），还包括光响应元件。表达模式分析表明，JcPAL1 在所有组织中均有表达，在花中表达量最高。用 ABA、GA3、高低温处理后，JcPAL1 的表达被诱导。重组 JcPAL1 在 100mM Tris-HCl 缓冲液中的最适 pH 为 8.7，最适温度为 60°C。Km 和 Kcat 值分别为 0.125mM 和 1.73S(-1)，L: -苯丙氨酸的 Km 和 Kcat 值分别为 1.312mM 和 0.109S(-1)，L: -酪氨酸。这些发现表明 JcPAL1 可能参与了麻疯树对各种胁迫的响应，L: -苯丙氨酸应该是其真正的生理底物。本研究对于揭示 PAL 是否以及如何在麻疯树的防御反应中启动苯丙烷代谢网络的功能具有重要意义。
