Varin L, Chamberland H, Lafontaine J G, Richard M
Biology Department, Concordia University, Montréal, Québec, Canada.
Plant J. 1997 Oct;12(4):831-7. doi: 10.1046/j.1365-313x.1997.12040831.x.
A sulfotransferase (ST) which catalyzes the transfer of sulfate from 3'-phosphoadenosine 5'-phosphosulfate (PAPS) to gallic acid glucoside was characterized from microsomal preparations of Mimosa pudica. The product of the reaction was found to co-elute on HPLC with the periodic leaf movement factor 1 (PLMF-1)(gallic acid beta-D-gluco-pyranosyl-6'-sulfate). The distribution of the enzyme activity was restricted to plasma membrane preparations from primary, secondary and tertiary pulvini. The M. pudica ST activity was inhibited in a dose-dependent manner in the presence of an antibody raised against the flavonol 3-sulfotransferase of Flaveria chloraefolia, suggesting structural similarities between the two proteins. Western blot analysis of M. pudica protein extracts using these antibodies indicated the presence of a cross-reactive polypeptide with an apparent molecular mass of 42,000 Da whose distribution correlates with the presence of the gallic acid glucoside ST activity. Indirect immunogold labeling of resin-embedded sections from tertiary pulvini showed a specific localization of gold particles on the sieve-tube plasma membranes. The label distribution was uniform and other cellular organelles and membrane systems displayed little or no labeling. The results of the Western blot and immunocytochemical studies are consistent with the detection of the gallic acid glucoside ST activity in plasma membrane preparations of M. pudica pulvini cells. The specific tissue distribution of the ST in motor organ phloem cells suggests that this is the site of synthesis and/or accumulation of PLMF-1 and supports the proposed hypothesis that PLMF-1 may be acting as a chemical signal during the seismonastic response of M. pudica.
从含羞草的微粒体制剂中鉴定出一种磺基转移酶（ST），它催化硫酸从3'-磷酸腺苷5'-磷酸硫酸酯（PAPS）转移至没食子酸葡萄糖苷。发现该反应产物在高效液相色谱（HPLC）上与周期性叶片运动因子1（PLMF-1）（β-D-吡喃葡萄糖基-6'-硫酸没食子酸）共洗脱。酶活性的分布局限于初生、次生和三生叶枕的质膜制剂。在存在针对绿黄菊黄酮醇3-磺基转移酶产生的抗体的情况下，含羞草ST活性呈剂量依赖性抑制，这表明两种蛋白质之间存在结构相似性。使用这些抗体对含羞草蛋白质提取物进行蛋白质免疫印迹分析表明，存在一种表观分子量为42,000 Da的交叉反应性多肽，其分布与没食子酸葡萄糖苷ST活性的存在相关。对三生叶枕树脂包埋切片的间接免疫金标记显示，金颗粒特异性定位于筛管质膜上。标记分布均匀，其他细胞器和膜系统几乎没有或没有标记。蛋白质免疫印迹和免疫细胞化学研究结果与在含羞草叶枕细胞的质膜制剂中检测到没食子酸葡萄糖苷ST活性一致。ST在运动器官韧皮部细胞中的特定组织分布表明，这是PLMF-1合成和/或积累的部位，并支持了PLMF-1可能在含羞草感震反应期间作为化学信号的假说。
