Actin monomer-binding proteins and the regulation of actin dynamics in plants
Actin monomer-binding proteins and the regulation of actin dynamics in plants
复制标题
DOI：
10.1007/s003440010010
复制
发表时间：
2001-06-01
影响因子：
4.8
通讯作者：
Gibbon, BC
中科院分区：
文献类型：
--
作者：
Gibbon, BC
植物对生存的环境和发育信号有独特的适应能力。许多信号导致依赖于肌动蛋白细胞骨架的细胞形状或细胞质组织的急剧变化。肌动蛋白细胞骨架的动态性质是由多种肌动蛋白结合蛋白决定的。其中一类蛋白质能够与游离的肌动蛋白单体结合，从而调节肌动蛋白细丝的聚合。已在植物中鉴定出两种这样的蛋白质：Profilin和肌动蛋白解聚因子(ADF)。这些蛋白质组成了植物中的多基因家族，每个蛋白质的亚型都有独特的发育和空间调节的表达模式。对植物单体结合蛋白的生化分析表明，它们在体外既能刺激肌动蛋白聚合，也能抑制肌动蛋白聚合。此外，将这些蛋白质微量注射到细胞中表明，单体结合蛋白与肌动蛋白相互作用的简单模型是不充分的。在体外和体内对肌动蛋白的复杂作用是由于Profilin和ADF能够与许多其他配体相互作用，如调节蛋白和多磷肌醇脂类。单体结合蛋白也对胞质呼唤和pH的变化做出反应。通过磷酸化来调节这些蛋白质，为研究它们在植物细胞中协调肌动蛋白重组的作用增加了额外的复杂性。提出了一个在尖端生长细胞中结合Profilin和ADF活性的肌动蛋白细丝组装模型。
Plants are uniquely adapted to respond to environmental and developmental signals for survival. Many signals result in dramatic changes of cell shape or cytoplasmic organization that are dependent on the actin cytoskeleton. The dynamic nature of the actin cytoskeleton is conferred by a wide variety of actin-binding proteins. One class of these proteins is capable of binding to free actin monomers and thereby regulates the polymerization of actin filaments. Two such proteins have been identified in plants: profilin and actin-depolymerizing factor (ADF). These proteins comprise multigene families in plants and the isoforms of each protein have unique developmentally and spatially regulated expression patterns. Biochemical analysis of the plant monomer-binding proteins indicates that they are able to both stimulate and inhibit actin polymerization in vitro. Furthermore, microinjection of these proteins into cells reveals that simple models for the interaction of monomer-binding proteins with actin are inadequate. The complex effects on actin in vitro and in vivo are due to the ability of profilin and ADF to interact with a number of other ligands, such as regulatory proteins and polyphosphoinositide lipids. The monomer-binding proteins also respond to changes in cytosolic Call and pH. Regulation of these proteins by phosphorylation adds an additional level of complexity for the study of their role in coordinating actin reorganization in plant cells. A model of actin filament assembly in tip-growing cells that incorporates the activities of profilin and ADF is presented.