植物细胞中的前纤维蛋白

肌动蛋白组成的微丝骨架是真核细胞中的重要结构，在体内处于高度动态变化之中，受多种肌动蛋白结合蛋白（actin-binding proteins）的调节。前纤维蛋白（profilin）是一种单体肌动蛋白结合蛋白，存在于所有的真核细胞中，在植物细胞中也得到较多的研究。前纤维蛋白除可以结合单体肌动蛋白之外，还可以与磷脂酰肌醇及富含多聚脯氨酸的蛋白质等多种分子结合，在细胞信号转导中行使着重要的功能。本文结合本实验室的研究结果，概述了前纤维蛋白的最新研究进展。

Profilins in Plant Cells

Actin cytoskeleton is one of the major components of cytoskeleton in eukaryotic cells. In response to endogenous cues or external signals, actin filaments undergo quick polymerization and depolymerization with result in rapid reconstruction of actin cytoskeleton. The dynamic rearrangement of actin filaments in cells are regulated by actin-binding proteins. Profilin is a low-molecular-weight, actin-monomer-binding protein ubiquitously presents in organisms ranging from amoebae and fungi up to higher plants and mammals. Besides binding actin, profilin also binds to phosphatidylinositol 4,5-bisphosphate and poly-Lproline. Recent studies suggest that profilin is a multifunctional protein that has positive and negative regulatory effects on actin polymerization and, in certain case, may be involved in signal transduction. We have long been engaged in the studies on characteristic and function of profilin in plant cells, such as the function analysis ofArabidopsis PRF1 and PRF2, and the effects of profilin on the function of forming in modulating actin cytoskeleton. Here, with the combination of our results, we have reviewed the recent progress in profilin research, including its initial finding, biochemical properties, in vivo distribution and functions, as well as its role in signal transduction.