MoCAP proteins regulated by MoArk1-mediated phosphorylation coordinate endocytosis and actin dynamics to govern development and virulence of Magnaporthe oryzae.
MoCAP proteins regulated by MoArk1-mediated phosphorylation coordinate endocytosis and actin dynamics to govern development and virulence of Magnaporthe oryzae.
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DOI：
10.1371/journal.pgen.1006814
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发表时间：
2017-05
期刊：
影响因子：
4.5
通讯作者：
Zhang Z
中科院分区：
文献类型：
--
作者：
Li L;Chen X;Zhang S;Yang J;Chen D;Liu M;Zhang H;Zheng X;Wang P;Peng Y;Zhang Z
肌动蛋白组织是一个保守的细胞过程，调节真核细胞的生长和发育。它还控制致病真菌的毒力过程，如稻瘟病菌，其机制尚未完全了解。在以前的研究中，我们发现肌动蛋白调节激酶MoArk 1在内吞和肌动蛋白组织中显示出重要的保守功能，并且MoArk 1是维持M的生长和完整毒力所必需的。米。为了了解MoArk 1的功能，我们从M.在体内与MoArk 1相互作用的MoCAP。MoCAP是由α和β亚基MoCapA和MoCapB组成的异源二聚体。MoCAP亚基的单缺失和双缺失导致菌丝生长和分生孢子形成异常。ΔMocap突变体还表现出减少附着胞穿透和侵入性菌丝生长在宿主细胞内。此外，ΔMocap突变体表现出延迟的内吞作用和异常的细胞骨架组装。与上述研究结果相一致，MoCAP蛋白与MoAct 1相互作用，在菌丝发育过程中与肌动蛋白共定位，并参与附着胞肌动蛋白环的形成。进一步的分析显示，MoCapA的S85残基和MoCapB的S285残基受到MoArk 1的磷酸化，其负调节MoCAP功能。最后，与野生型菌株相比，添加外源性磷脂酰肌醇4，5-二磷酸（PIP 2）未能调节ΔMocap突变体中肌动蛋白环的形成，这表明MoCAP也可能介导磷脂信号转导调节肌动蛋白组织。这些结果共同表明，MoCAP蛋白，其功能由MoArk 1和PIP 2调节是重要的内吞作用和肌动蛋白动力学，直接连接到生长，分生孢子和致病性的M。米。肌动蛋白调节激酶MoArk 1在内吞和肌动蛋白组织中起保守的作用，并且对于稻瘟病菌的生长和完全毒力也是必需的。为了了解MoArk 1的功能，我们鉴定了与MoArk 1相互作用的F-肌动蛋白帽蛋白α（MoCapA）和β（MoCapB）亚基。我们发现MoCAPA和MoCAPB的单缺失和双缺失导致生长减缓，分生孢子产量减少，形态发生异常和毒力减弱。我们发现ΔMocap突变体在胞吞作用和肌动蛋白组织方面存在缺陷，并且MoCAP蛋白通过蛋白磷酸化受到MoArk 1的调节。最后，我们提供的证据表明，MoCAP蛋白调节肌动蛋白动力学响应磷脂酰肌醇4，5-二磷酸（PIP 2）。这些综合结果表明，MoCAP蛋白发挥重要作用的内吞作用，肌动蛋白的组织，和毒力。对MoCAP蛋白的进一步研究将有助于更好地理解肌动蛋白组织与宿主感染之间的关系。米。
Actin organization is a conserved cellular process that regulates the growth and development of eukaryotic cells. It also governs the virulence process of pathogenic fungi, such as the rice blast fungus Magnaporthe oryzae, with mechanisms not yet fully understood. In a previous study, we found that actin-regulating kinase MoArk1 displays conserved functions important in endocytosis and actin organization, and MoArk1 is required for maintaining the growth and full virulence of M. oryzae. To understand how MoArk1 might function, we identified capping protein homologs from M. oryzae (MoCAP) that interact with MoArk1 in vivo. MoCAP is heterodimer consisting of α and β subunits MoCapA and MoCapB. Single and double deletions of MoCAP subunits resulted in abnormal mycelial growth and conidia formation. The ΔMocap mutants also exhibited reduced appressorium penetration and invasive hyphal growth within host cells. Furthermore, the ΔMocap mutants exhibited delayed endocytosis and abnormal cytoskeleton assembly. Consistent with above findings, MoCAP proteins interacted with MoAct1, co-localized with actin during mycelial development, and participated in appressorial actin ring formation. Further analysis revealed that the S85 residue of MoCapA and the S285 residue of MoCapB were subject to phosphorylation by MoArk1 that negatively regulates MoCAP functions. Finally, the addition of exogenous phosphatidylinositol 4,5-bisphosphate (PIP2) failed to modulate actin ring formation in ΔMocap mutants, in contrast to the wild-type strain, suggesting that MoCAP may also mediate phospholipid signaling in the regulation of the actin organization. These results together demonstrate that MoCAP proteins whose functions are regulated by MoArk1 and PIP2 are important for endocytosis and actin dynamics that are directly linked to growth, conidiation and pathogenicity of M. oryzae. The actin-regulating kinase MoArk1 plays a conserved function in endocytosis and actin organization and is also essential for growth and full virulence of the rice blast fungus Magnaporthe oryzae. To understand how MoArk1 functions, we identified the F-actin capping protein α (MoCapA) and β (MoCapB) subunits that interact with MoArk1. We showed that single and double deletions of MoCAPA and MoCAPB result in slowed growth, reduced conidia production, abnormal morphogenesis, and attenuated virulence. We found that ΔMocap mutants are defective in endocytosis and actin organization and that MoCAP proteins are subject to regulation by MoArk1 through protein phosphorylation. Finally, we provided evidence demonstrating that MoCAP proteins modulate actin dynamics in response to phosphatidylinositol 4,5-biphosphate (PIP2). These combined results suggest that MoCAP proteins play an important role in endocytosis, actin organization, and virulence. Further studies of MoCAP proteins could lead to a better understanding of the connections between actin organization and host infection by M. oryzae.