《植物生理学报》 2015, 51(10): 1590-1596

植物细胞中磷酸肌醇和磷脂酶C介导的信号转导

李莉, 井文^*, 章文华

南京农业大学生命科学学院, 南京210095

通信作者：井；E-mail: jingwen@njau.edu.cn；Tel: 025-84399786

摘　要：

磷酸肌醇(PIs)是磷脂酰肌醇(PtdIns)单、双、三磷酸化产物的总称。磷脂酶C (PLC)水解磷脂酰肌醇-4,5-二磷酸[PtdIns(4,5)P₂]产生二酰甘油(DAG)和肌醇三磷酸(InsP₃), 此双信使系统的靶蛋白分别是蛋白激酶C (PKC)和InsP₃受体(钙通道蛋白)。此经典的信号途径是从动物细胞中发现的。到目前为止, 植物中没有发现PKC或InsP₃受体, 但有其独特的磷酸肌醇信号组分和途径。与动物不同, 植物PI含量最高的是磷脂酰肌醇-4-磷酸(PtdIns4P), 最多可达PtdIns(4,5)P₂的100倍; 而DAG磷酸化产物磷脂酸(PA)和InsP₃磷酸化产物肌醇六磷酸(InsP₆)也被证明是植物中重要的信号分子。本文通过比较动、植物细胞中PI和PLC信号途径的差异, 综述了植物细胞中PI和PLC途径的独特作用和调控机理。

关键词：磷酸肌醇; 磷脂酶C; 信号转导

收稿：2015-08-17   修定：2015-09-23

资助：国家自然科学基金(31171461和31301294)。

Signal Transduction by Phosphoinositides and Phospholipase C in Plant Cells

LI Li, JING Wen^*, ZHANG Wen-Hua

College of Life Sciences, Nanjing Agricultural University, Nanjing 210095, China

Corresponding author: JING Wen; E-mail: jingwen@njau.edu.cn; Tel: 025-84399786

Abstract:

Phosphoinositides (PIs) are mono-, bis-, or tris-phosphorylated derivatives of phosphatidylinositol (PtdIns). Phosphatidylinositol 4,5-bisphosphate [PtdIns(4,5)P₂] can be hydrolyzed by phospholipase C (PLC) to produce diacylglycerol (DAG) and inositol trisphosphates (InsP₃). In animal cells, DAG and InsP₃ are important second messengers that activate protein kinase C (PKC) and InsP₃ receptor (Ca²⁺ channel), respectively. However, neither PKC nor InsP₃ receptor has been found in plant cells. Instead, there are unique phosphoinositide signaling pathways in plant cells. In plants, PtdIns4P is the most abundant PI, and the ratio of phosphatidylinositol 4-phosphate (PtdIns4P) to PtdIns(4,5)P₂ is as high as 100 to 1. The phosphorylated products of DAG and InsP3, phosphatidic acid (PA) and inositol hexakisphosphate (InsP₆), respectively, are as signaling molecules in plants. This paper compared the PI and PLC signalings between plant and animal cells, and summarized the unique mechanism of PI and PLC pathways in plant cells.

Key words: phosphoinositides; phospholipase C; signal transduction