Molecular characterization of a fungal gasdermin-like protein
Molecular characterization of a fungal gasdermin-like protein
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DOI：
10.1073/pnas.2004876117
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发表时间：
2020-08-04
影响因子：
11.1
通讯作者：
Glass, N. Louise
中科院分区：
文献类型：
--
作者：
Daskalov, Asen;Mitchell, Patrick S.;Glass, N. Louise
丝状真菌中的程序性细胞死亡（PCD）防止同种遗传上不同的个体之间融合后的细胞质混合（异源识别），并用作对抗真菌寄生、基因组利用和有害细胞质元件（即，衰老质粒）。最近，我们发现了细胞死亡调节因子-1（rcd-1），这是一种控制丝状真菌粗糙脉孢菌萌发无性孢子中细胞程序死亡的基因。rcd-1等位基因在N. crassa种群。来自两个单倍型群rcd-1-1和rcd-1-2的等位基因的共表达对于触发细胞死亡反应是必要且充分的。在这里，我们研究了rcd-1依赖性细胞死亡的分子基础。基于计算机模拟分析，我们发现RCD-1是gasdermin的N-末端成孔结构域的远程同源物，gasdermin是高度炎症性细胞死亡反应（称为pyroptosis）的执行蛋白，在哺乳动物先天免疫中起关键作用。我们发现，RCD-1定位于细胞周边，RCD-1的细胞定位与预测的两亲性α-螺旋上的保守的带正电荷的残基相关，如鼠gasdermin-D所示。与gasdermin类似，RCD-1在体外结合酸性磷脂，特别是心磷脂和磷脂酰丝氨酸，并与含有此类脂质的脂质体相互作用。在人293 T细胞中重建了RCD-1不相容系统，其中不相容rcd-1-1/rcd-1-2等位基因的共表达触发了pyroptotic样细胞死亡。RCD-1的寡聚体与细胞死亡反应相关，进一步支持gasdermin和rcd-1之间的进化关系。这份报告记录了一个古老的跨王国关系的细胞死亡执行模块参与有机体防御。
Programmed cell death (PCD) in filamentous fungi prevents cytoplasmic mixing following fusion between conspecific genetically distinct individuals (allorecognition) and serves as a defense mechanism against mycoparasitism, genome exploitation, and deleterious cytoplasmic elements (i.e., senescence plasmids). Recently, we identified regulator of cell death-1 (rcd-1), a gene controlling PCD in germinated asexual spores in the filamentous fungus Neurospora crassa. rcd-1 alleles are highly polymorphic and fall into two haplogroups in N. crassa populations. Coexpression of alleles from the two haplogroups, rcd-1-1 and rcd-1-2, is necessary and sufficient to trigger a cell death reaction. Here, we investigated the molecular bases of rcd-1-dependent cell death. Based on in silico analyses, we found that RCD-1 is a remote homolog of the N-terminal pore-forming domain of gasdermin, the executioner protein of a highly inflammatory cell death reaction termed pyroptosis, which plays a key role in mammalian innate immunity. We show that RCD-1 localizes to the cell periphery and that cellular localization of RCD-1 was correlated with conserved positively charged residues on predicted amphipathic alpha-helices, as shown for murine gasdermin-D. Similar to gasdermin, RCD-1 binds acidic phospholipids in vitro, notably, cardiolipin and phosphatidylserine, and interacts with liposomes containing such lipids. The RCD-1 incompatibility system was reconstituted in human 293T cells, where coexpression of incompatible rcd-1-1/rcd-1-2 alleles triggered pyroptotic-like cell death. Oligomers of RCD-1 were associated with the cell death reaction, further supporting the evolutionary relationship between gasdermin and rcd-1. This report documents an ancient transkingdom relationship of cell death execution modules involved in organismal defense.