Pollen profilin function depends on interaction with proline-rich motifs
Pollen profilin function depends on interaction with proline-rich motifs
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DOI：
10.1105/tpc.10.6.981
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发表时间：
1998-06-01
期刊：
影响因子：
11.6
通讯作者：
Staiger, CJ
中科院分区：
文献类型：
--
作者：
Gibbon, BC;Zonia, LE;Staiger, CJ
肌动蛋白结合蛋白profilin在体外和活细胞中对肌动蛋白聚合有显著影响。植物有大的多基因家族编码profilins，许多细胞或组织可以表达多种profilin异构体，最近，我们的特点是几个profilin异构体从玉米花粉的能力，改变细胞结构时，显微注射到活的植物细胞和他们的协会与聚-L-脯氨酸和单体肌动蛋白从玉米花粉。在这项研究中，我们表征了一种新的profilin异构体从玉米，这已被指定为ZmPRO 4，这是主要在胚乳中表达，但也发现在所有组织检查，包括成熟和萌发的花粉在低水平。通过两种独立的方法测量的ZmPRO 4对单体肌动蛋白的亲和力与先前在花粉中鉴定的三种profilin同种型的亲和力相似。相比之下，ZmPRO 4对聚-L-脯氨酸的亲和力比天然花粉抑制蛋白和其他重组抑制蛋白同种型的亲和力高近两倍。当ZmPRO 4被显微注射到植物细胞中，肌动蛋白依赖的核位置的影响是显着更快的比另一个花粉profilin亚型，ZmPRO 1。创建了功能获得性突变体（ZmPRO 1-Y 6 F），并发现其与ZmPRO 4一样有效地增强聚-L-脯氨酸结合活性并破坏细胞结构。在这项研究中，我们表明，在一个单一的细胞中表达的profilin亚型可以有不同的影响，在活细胞中的肌动蛋白和多聚-L-脯氨酸结合功能的profilin可能有重要的后果，在植物细胞中的肌动蛋白细胞骨架动力学的调节。
The actin binding protein profilin has dramatic effects on actin polymerization in vitro and in living cells. Plants have large multigene families encoding profilins, and many cells or tissues can express multiple profilin isoforms, Recently, we characterized several profilin isoforms from maize pollen for their ability to alter cytoarchitecture when microinjected into living plant cells and for their association with poly-L-proline and monomeric actin from maize pollen. In this study, we characterize a new profilin isoform from maize, which has been designated ZmPRO4, that is expressed predominantly in endosperm but is also found at low levels in all tissues examined, including mature and germinated pollen. The affinity of ZmPRO4 for monomeric actin, which was measured by two independent methods, is similar to that of the three profilin isoforms previously identified in pollen. In contrast, the affinity of ZmPRO4 for poly-L-proline is nearly twofold higher than that of native pollen profilin and the other recombinant profilin isoforms. When ZmPRO4 was microinjected into plant cells, the effect on actin-dependent nuclear position was significantly more rapid than that of another pollen profilin isoform, ZmPRO1. A gain-of-function mutant (ZmPRO1-Y6F) was created and found to enhance poly-L-proline binding activity and to disrupt cytoarchitecture as effectively as ZmPRO4. In this study, we demonstrate that profilin isoforms expressed in a single cell can have different effects on actin in living cells and that the poly-L-proline binding function of profilin may have important consequences for the regulation of actin cytoskeletal dynamics in plant cells.