Profilin promotes formin-mediated actin filament assembly and vesicle transport during polarity formation in pollen
Profilin promotes formin-mediated actin filament assembly and vesicle transport during polarity formation in pollen
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Profilin 在花粉极性形成过程中促进福尔明介导的肌动蛋白丝组装和囊泡运输
DOI：
10.1093/plcell/koab027
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发表时间：
2021-02-08
期刊：
影响因子：
11.6
通讯作者：
Ren, Haiyun
中科院分区：
文献类型：
--
作者：
Liu, Chang;Zhang, Yi;Ren, Haiyun
花粉萌发对开花植物的繁殖至关重要。形成蛋白依赖的肌动蛋白聚合在囊泡运输和极性建立过程中起着至关重要的作用。然而，如何在体内调节formin介导的肌动蛋白组装仍然知之甚少。在这里，我们研究了生殖profilin 4和5（PRF4和PRF5）的极性建立在拟南芥花粉萌发过程中的功能。我们的数据表明，肌动蛋白丝含量减少prf4 prf5双突变体和显着增加PRF4和PRF5过表达的花粉粒。相比之下，profilin在促进肌动蛋白聚合的积极作用被废除在一个cytokine突变体，atfh5。此外，拟南芥同源5（AtFH 5）和肌动蛋白丝之间的相互作用减弱和AtFH 5标记的小泡的运输减慢prf 4 prf 5花粉粒。prf4、prf5花粉粒萌发孔处的领状结构的形成也有缺陷，这是由于肌动蛋白丝的快速组装受损。总之，我们的研究结果表明，PRF4和PRF5调节囊泡运输和极性建立花粉萌发过程中，通过促进AtFH 5介导的肌动蛋白聚合和增强AtFH 5和肌动蛋白丝之间的相互作用。
Pollen germination is critical for the reproduction of flowering plants. Formin-dependent actin polymerization plays vital roles in vesicle trafficking and polarity establishment during this process. However, how formin-mediated actin assembly is regulated in vivo remains poorly understood. Here, we investigated the function of reproductive profilin 4 and 5 (PRF4 and PRF5) in polarity establishment during pollen germination in Arabidopsis thaliana. Our data showed that the actin filament content was reduced in the prf4 prf5 double mutant and substantially increased in both PRF4- and PRF5-overexpressing pollen grains. By contrast, the positive effect of profilin in promoting actin polymerization was abolished in a formin mutant, atfh5. In addition, the interaction between Arabidopsis formin homology 5 (AtFH5) and actin filaments was attenuated and the trafficking of AtFH5-labeled vesicles was slowed in prf4 prf5 pollen grains. Formation of the collar-like structure at the germination pore was also defective in prf4 prf5 pollen grains as the fast assembly of actin filaments was impaired. Together, our results suggest that PRF4 and PRF5 regulate vesicle trafficking and polarity establishment during pollen germination by promoting AtFH5-mediated actin polymerization and enhancing the interaction between AtFH5 and actin filaments.