Two class XI myosins function in organelle trafficking and root hair development in Arabidopsis
Two class XI myosins function in organelle trafficking and root hair development in Arabidopsis
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DOI：
10.1104/pp.107.113654
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发表时间：
2008-03-01
期刊：
影响因子：
7.4
通讯作者：
Dolja, Valerian V.
中科院分区：
文献类型：
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作者：
Peremyslov, Valera V.;Prokhnevsky, Alexey I.;Dolja, Valerian V.
编码XI类肌球蛋白的多基因家族在高等植物中是保守的，然而，关于这些普遍存在的分子马达的具体功能的信息很少。我们分离了拟南芥基因组中所有13类XI肌球蛋白的基因敲除突变体。在正常生长条件下，11个肌球蛋白基因失活导致无明显表型。相比之下，其余两个肌球蛋白基因XI-2（以前的MYA2）和XI-K的敲除在根毛伸长方面表现出类似的缺陷，这表明肌球蛋白驱动的运动性在极尖生长中起着重要作用。引人注目的是，这些肌球蛋白的失活也减少了根毛和叶表皮细胞中高尔基堆积、过氧化物酶体和线粒体的运输。这些结果表明，肌凝蛋白XI-K和XI-2在拟南芥细胞动力学中起着重要的重叠作用，并突出了肌凝蛋白在植物中功能的冗余性。
Multigene families encoding class XI myosins are conserved in higher plants, however, little information is available on specific functions of these ubiquitous molecular motors. We isolated gene knockout mutants for all 13 class XI myosins present in Arabidopsis ( Arabidopsis thaliana) genome. Inactivation of 11 myosin genes resulted in no discernible phenotypes under the normal growth conditions. In contrast, the knockouts of the remaining two myosin genes, XI-2 ( formerly MYA2) and XI-K, exhibited similar defects in root hair elongation suggesting that the myosin- driven motility plays a significant role in a polar tip growth. Strikingly, inactivation of each of these myosins also reduced trafficking of Golgi stacks, peroxisomes, and mitochondria in root hairs and in leaf epidermal cells. These results indicate that myosins XI-K and XI-2 play major and overlapping roles in the cell dynamics in Arabidopsis and highlight the redundant nature of myosin function in plants.