Oecking C, Eckerskorn C, Weiler E W
Lehrstuhl für Pflanzenphysiologie, Ruhr-Universität, Bochum, Germany.
FEBS Lett. 1994 Sep 26;352(2):163-6. doi: 10.1016/0014-5793(94)00949-x.
The receptor for the wilt-inducing phytotoxin fusicoccin was purified to homogeneity from plasma membranes of Commelina communis as a complex with the radioligand [3H]9'-nor-8'-hydroxyfusicoccin. The preparation consisted of two polypeptides with apparent molecular masses of 30.5 kDa and 31.5 kDa and with isoelectric points of around pH 5.2 and 5.3, respectively. The proteins were N-terminally blocked. Internal amino acid sequences were obtained for both polypeptides of the fusicoccin-binding complex. Sequence information, as well as subsequent immunological analysis, proved that both polypeptides are members of the eukaryotic 14-3-3 family, which comprises structurally conserved regulatory proteins of widespread occurrence and a wide range of functions. 14-3-3 isoform(s) constituting the fusicoccin receptor are distinguishable from other cellular 14-3-3 proteins by their tight association with the plasma membrane. Applying temperature-induced Triton X-114 phase separation experiments, they, as well as the target enzyme of fusicoccin action, the H(+)-ATPase, partitioned into the phospholipid-rich fraction which contains the most hydrophobic proteins. The results discussed herein provide a basis for the elucidation of the molecular mechanism of fusicoccin action.
从鸭跖草的质膜中，以与放射性配体[3H]9'-去甲-8'-羟基藤霉素形成的复合物形式，将诱导枯萎的植物毒素藤霉素的受体纯化至同质。该制剂由两条多肽组成，表观分子量分别为30.5 kDa和31.5 kDa，等电点分别约为pH 5.2和5.3。这些蛋白质的N端被封闭。获得了藤霉素结合复合物两条多肽的内部氨基酸序列。序列信息以及随后的免疫学分析证明，这两条多肽都是真核14-3-3家族的成员，该家族由广泛存在且具有多种功能的结构保守的调节蛋白组成。构成藤霉素受体的14-3-3同工型与其他细胞14-3-3蛋白的区别在于它们与质膜紧密结合。通过温度诱导的Triton X-114相分离实验，它们以及藤霉素作用的靶酶H(+)-ATPase都分配到了富含磷脂的部分，该部分包含最疏水的蛋白质。本文讨论的结果为阐明藤霉素作用的分子机制提供了基础。
