Lamm-Schmidt Vanessa, Fuchs Manuela, Sulzer Johannes, Gerovac Milan, Hör Jens, Dersch Petra, Vogel Jörg, Faber Franziska
Faculty of Medicine, Institute of Molecular Infection Biology (IMIB), University of Würzburg, Josef-Schneider-Straße 2/D15, 97080 Würzburg, Germany.
Centre for Molecular Biology of Inflammation, Institute for Infectiology, University of Münster, Von-Esmarch-Straße 56, 48149 Münster, Germany.
Microlife. 2021 Apr 22;2:uqab004. doi: 10.1093/femsml/uqab004. eCollection 2021.
Much of our current knowledge about cellular RNA-protein complexes in bacteria is derived from analyses in gram-negative model organisms, with the discovery of RNA-binding proteins (RBPs) generally lagging behind in Gram-positive species. Here, we have applied Grad-seq analysis of native RNA-protein complexes to a major Gram-positive human pathogen, , whose RNA biology remains largely unexplored. Our analysis resolves in-gradient distributions for ∼88% of all annotated transcripts and ∼50% of all proteins, thereby providing a comprehensive resource for the discovery of RNA-protein and protein-protein complexes in and related microbes. The sedimentation profiles together with pulldown approaches identify KhpB, previously identified in , as an uncharacterized, pervasive RBP in . Global RIP-seq analysis establishes a large suite of mRNA and small RNA targets of KhpB, similar to the scope of the Hfq targetome in . The KhpB-bound transcripts include several functionally related mRNAs encoding virulence-associated metabolic pathways and toxin A whose transcript levels are observed to be increased in a deletion strain. Moreover, the production of toxin protein is also increased upon deletion. In summary, this study expands our knowledge of cellular RNA protein interactions in and supports the emerging view that KhpB homologues constitute a new class of globally acting RBPs in Gram-positive bacteria.
我们目前对细菌中细胞RNA-蛋白质复合物的许多认识都来自对革兰氏阴性模式生物的分析,而RNA结合蛋白(RBP)在革兰氏阳性菌中的发现通常滞后。在这里,我们将天然RNA-蛋白质复合物的梯度离心分析应用于一种主要的革兰氏阳性人类病原体,其RNA生物学在很大程度上仍未被探索。我们的分析解析了约88%的所有注释转录本和约50%的所有蛋白质的梯度内分布,从而为发现该病原体及相关微生物中的RNA-蛋白质和蛋白质-蛋白质复合物提供了全面的资源。沉降谱与下拉方法共同确定了先前在其他研究中鉴定出的KhpB,它是该病原体中一种未被表征的普遍存在的RBP。全局RIP-seq分析确定了KhpB的一大组mRNA和小RNA靶标,类似于该病原体中Hfq靶标组的范围。与KhpB结合的转录本包括几个编码与毒力相关代谢途径的功能相关mRNA以及毒素A,在缺失菌株中观察到其转录水平增加。此外,在缺失该病原体时毒素蛋白的产生也会增加。总之,这项研究扩展了我们对该病原体中细胞RNA-蛋白质相互作用的认识,并支持了一种新出现的观点,即KhpB同源物构成了革兰氏阳性菌中一类新的全局作用的RBP。