A glycine-rich protein MoGrp1 functions as a novel splicing factor to regulate fungal virulence and growth in Magnaporthe oryzae
A glycine-rich protein MoGrp1 functions as a novel splicing factor to regulate fungal virulence and growth in Magnaporthe oryzae
复制标题
富含甘氨酸的蛋白 MoGrp1 作为一种新型剪接因子来调节稻瘟病菌的真菌毒力和生长
DOI：
10.1186/s42483-018-0007-1
复制
发表时间：
2019-01-01
影响因子：
3.4
通讯作者：
Peng, You-Liang
中科院分区：
文献类型：
--
作者：
Gao, Xusheng;Yin, Changfa;Peng, You-Liang
富含甘氨酸的蛋白质（GRPs）具有多种氨基酸序列，参与多种生物过程。GRPs在植物病原真菌中的作用尚未见报道。在这项研究中，我们鉴定了一个名为MoGRP1的新基因，并对其进行了功能表征，该基因编码一个具有n端RNA识别基序（RRM）和c端富含甘氨酸结构域的蛋白，具有4个Arg-Gly-Gly （RGG）重复序列。MoGRP1的缺失导致真菌毒力、菌丝生长和分生率的显著降低。ΔMogrp1突变体在细胞壁完整性和对不同胁迫的反应方面也存在缺陷。MoGrp1定位于细胞核，并与剪接体的几个组分共免疫沉淀，包括U1 snRNP和U2 snRNP复合物的亚基。此外，MoGrp1对poly(U)具有结合亲和力。重要的是，MoGrp1负责参与感染相关形态发生的基因的正常剪接。结构域缺失分析表明，RRM结构域及其相邻的两个RGG重复序列对于MoGrp1的完整功能都是必不可少的。值得注意的是，第一和第二个RGG重复序列之间的9个氨基酸对于MoGrp1的核定位和生物学功能是必不可少的。综上所述，我们的数据表明MoGrp1是一种具有聚(U)结合活性的新型剪接因子，可调节稻瘟病菌的毒力、发育和胁迫反应。
Glycine-rich proteins (GRPs) have diverse amino acid sequences and are involved in a variety of biological processes. The role of GRPs in plant pathogenic fungi has not been reported. In this study, we identified and functionally characterized a novel gene named MoGRP1 in Magnaporthe oryzae, which encodes a protein that has an N-terminal RNA recognition motif (RRM) and a C-terminal glycine-rich domain with four Arg-Gly-Gly (RGG) repeats. Deletion of MoGRP1 resulted in dramatic reductions in fungal virulence, mycelial growth, and conidiation. The ΔMogrp1 mutants were also defective in cell wall integrity and in their responses to different stresses. MoGrp1 was localized to the nucleus and was co-immunoprecipitated with several components of the spliceosome, including subunits of the U1 snRNP and U2 snRNP complexes. Moreover, MoGrp1 exhibited binding affinity for poly(U). Importantly, MoGrp1 was responsible for the normal splicing of genes involved in infection-related morphogenesis. Domain deletion assays showed that both the RRM domain and its two adjacent RGG repeats were essential to the full function of MoGrp1. Notably, the nine amino acids between the first and the second RGG repeats were indispensable for nuclear localization and for the biological functions of MoGrp1. Taken together, our data suggest that MoGrp1 functions as a novel splicing factor with poly(U) binding activity to regulate fungal virulence, development, and stress responses in the rice blast fungus.