Arginine methylation is required for remodelling pre-mRNA splicing and induction of autophagy in rice blast fungus
Arginine methylation is required for remodelling pre-mRNA splicing and induction of autophagy in rice blast fungus
复制标题
稻瘟病菌中前体 mRNA 剪接的重塑和自噬的诱导需要精氨酸甲基化
DOI：
10.1111/nph.16156
复制
发表时间：
2019-09-30
期刊：
影响因子：
9.4
通讯作者：
Liu, Wende
中科院分区：
文献类型：
--
作者：
Li, Zhiqiang;Wu, Liye;Liu, Wende
蛋白质精氨酸甲基转移酶（PRMT）调节许多生理过程，包括自噬。然而，各种PRMT在自噬体形成过程中的直接作用仍不清楚。在这里，我们的特点MoHMT 1在稻瘟病菌，Magnaporthe稻瘟病菌的功能。MoHMT 1基因的敲除导致水稻幼苗生长受到抑制，引起病害的能力降低。MoHMT 1催化MoSNP 1（一种U1小核核糖核蛋白（snRNP）组分）的精氨酸247、251、261和271残基的二甲基化，可能以依赖于直接相互作用的方式进行。RNA-seq分析显示，与正常生长条件下的野生型菌株相比，MoHMT 1缺失突变体中558个基因（包括自噬相关（ATG）基因MoATG 4）的前mRNA的选择性剪接发生了改变。在光照或氮饥饿期间，MoHMT 1定位于自噬体，MoHMT 1突变体在自噬诱导中显示缺陷。氮饥饿下，6个额外的MoATG基因被确定保留在其mRNA转录的内含子，相应的内含子剪接的异构体在MoHMT 1突变株的转录显着减少。我们的研究表明，精氨酸甲基化在一系列发育过程（包括自噬体形成）所必需的精确前mRNA剪接中起着至关重要的作用。
Protein arginine methyltransferases (PRMTs) regulate many physiological processes, including autophagy. However, the direct roles of the various PRMTs during autophagosome formation remain unclear. Here, we characterised the function of MoHMT1 in the rice blast fungus, Magnaporthe oryzae. Knockout of MoHMT1 results in inhibited growth and a decreased ability to cause disease lesions on rice seedlings. MoHMT1 catalyses the di-methylation of arginine 247, 251, 261 and 271 residues of MoSNP1, a U1 small nuclear ribonucleoprotein (snRNP) component, likely in a manner dependent on direct interaction. RNA-seq analysis revealed that alternative splicing of pre-mRNAs of 558 genes, including the autophagy-related (ATG) gene MoATG4, was altered in MoHMT1 deletion mutants, compared with wild-type strains under normal growth conditions. During light exposure or nitrogen starvation, MoHMT1 localises to autophagosomes and MoHMT1 mutants display defects in autophagy induction. Under nitrogen starvation, six additional MoATG genes were identified with retained introns in their mRNA transcripts, corresponding with a significant reduction in transcripts of intron-spliced isoforms in the MoHMT1 mutant strain. Our study shows that arginine methylation plays an essential role in accurate pre-mRNA splicing necessary for a range of developmental processes, including autophagosome formation.