PDF(Pubmed)
Abstract：
Mycobacterial membrane proteins play a pivotal role in the bacterial invasion of host cells; however, the precise mechanisms underlying certain membrane proteins remain elusive. Mycolicibacterium smegmatis (Ms) msmeg5257 is a hemolysin III family protein that is homologous to Mycobacterium tuberculosis (Mtb) Rv1085c, but it has an unclear function in growth. To address this issue, we utilized the CRISPR/Cas9 gene editor to construct Δmsmeg5257 strains and combined RNA transcription and LC-MS/MS protein profiling to determine the functional role of msmeg5257 in Ms growth. The correlative analysis showed that the deletion of msmeg5257 inhibits ABC transporters in the cytomembrane and inhibits the biosynthesis of amino acids in the cell wall. Corresponding to these results, we confirmed that MSMEG5257 localizes in the cytomembrane via subcellular fractionation and also plays a role in facilitating the transport of iron ions in environments with low iron levels. Our data provide insights that msmeg5257 plays a role in maintaining Ms metabolic homeostasis, and the deletion of msmeg5257 significantly impacts the growth rate of Ms. Furthermore, msmeg5257, a promising drug target, offers a direction for the development of novel therapeutic strategies against mycobacterial diseases.
摘要：
分枝杆菌膜蛋白在细菌入侵宿主细胞中起着举足轻重的作用;然而,某些膜蛋白的确切机制仍然难以捉摸。耻垢分枝杆菌（Ms）msmg5257是一种溶血素III家族蛋白，与结核分枝杆菌（Mtb）Rv1085c同源，但它在增长中的作用不明确。为了解决这个问题，我们利用CRISPR/Cas9基因编辑器构建Δmsmeg5257菌株，并结合RNA转录和LC-MS/MS蛋白谱分析来确定msmeg5257在Ms生长中的功能作用。相关分析表明，msmeg5257的缺失抑制了细胞膜中的ABC转运蛋白，并抑制了细胞壁中氨基酸的生物合成。与这些结果相对应,我们证实MSMEG5257通过亚细胞分级分离定位在细胞膜中,并且在低铁水平环境中促进铁离子的运输方面也起作用.我们的数据提供了msmeg5257在维持Ms代谢稳态方面发挥作用的见解，msmeg5257的缺失显著影响了Ms的增长率。msmg5257，一个有前途的药物靶标，为开发针对分枝杆菌疾病的新型治疗策略提供了方向。
