Department of Plant and Environmental Sciences, Weizmann Institute of Science, Rehovot, Israel.
J Exp Bot. 2019 Apr 12;70(7):2077-2085. doi: 10.1093/jxb/ery460.
The serpins are a family of structurally conserved protease inhibitors found in all animal and plant kingdoms. After interaction with their cognate substrate(s), their native energetically stressed state is relaxed by hydrolysis, resulting in a semi-stable covalent bond that disables the protease. The inherent flexible serpin structure supports additional non-inhibitory functions. This review will focus on several biological functions attributed to plant serpins, ranging from specific cell death protease inhibitors to a stabilizing role for β-amylase in seeds. Functional conservation of a particular serpin type, the LR serpins, is suggested by its compelling ubiquity throughout the plant kingdom. The multiple target specificity of plant serpins including the LR serpins enables them to perform dual functions that are not mutually exclusive both as a regulator of cell death and as a protective anti-pathogenic protein.
丝氨酸蛋白酶抑制剂是一类结构保守的蛋白酶抑制剂，存在于所有的动物和植物界中。与它们的同源底物相互作用后，通过水解使它们原本能量紧张的状态得到松弛，从而形成一个半稳定的共价键，使蛋白酶失活。丝氨酸蛋白酶抑制剂固有的灵活结构支持额外的非抑制性功能。这篇综述将集中讨论几种归因于植物丝氨酸蛋白酶抑制剂的生物学功能，范围从特定的细胞死亡蛋白酶抑制剂到种子中β-淀粉酶的稳定作用。特定丝氨酸蛋白酶抑制剂类型（LR 丝氨酸蛋白酶抑制剂）的功能保守性，通过其在植物界中的广泛存在得到了强烈的支持。植物丝氨酸蛋白酶抑制剂，包括 LR 丝氨酸蛋白酶抑制剂，具有多种靶标特异性，使它们能够发挥双重功能，既是细胞死亡的调节剂，也是保护性的抗病原蛋白。
