长相核心蛋白和A类PBP1a在Streptococcus pneumoniae中细胞中显示区域性,过程性运动
bioRxiv : the preprint server for biology
|February 8, 2024
概括
细菌细胞壁的合成涉及两个关键的蛋白质复合体. 肺炎球菌延长体蛋白质在细胞中间环形移动,由细胞壁合成驱动,其中一些也在细胞表面表现出扩散运动.
科学领域:
- 微生物学和分子生物学
- 细菌细胞分裂和形态发生
背景情况:
- 肺炎 estreptococcus (pneumococcus) 使用不同的糖甘 (PG) 合成纳米机来进行细胞分裂和延长.
- 隔膜PG合成酶 (bPBP2x:FtsW) 关闭细胞隔膜,而延长体合成了外围PG.
- 之前的研究表明,隔膜PG合成酶在PG合成的驱动下,在中细胞环周移动.
研究的目的:
- 为了研究肺炎球菌延长体内蛋白质的动态.
- 了解驱动细胞分裂过程中长相蛋白运动和局部化的机制.
主要方法:
- 使用单分子全内反射光显微镜 (sm-TIRFm) 来追踪蛋白质动态.
- 进行了蛋白质耗尽实验,以评估长相组件的相互依赖性.
- 分析的重点是关键的长相蛋白的运动模式 (环形,扩散,静态).
主要成果:
- 核心延长体蛋白 (bPBP2b,Roda,MreC) 在中细胞表现出环形运动,由PG合成驱动.
- 这些蛋白质还在细胞中间区域外的细胞表面显示扩散运动.
- bPBP2b和Roda在定位和运动方面相互依赖;MreC的耗尽取消了bPBP2b的环形运动.
- 甲类青素结合蛋白1a (aPBP1a) 在中细胞表现出短暂的环周运动,与静态和扩散性群体一起.
- 穆拉米达酶MpgA表现出有限的,亚扩散的运动,主要在中细胞区域.
结论:
- 肺炎球菌延长体蛋白具有动态调节,具有独特的运动模式,有助于细胞壁合成.
- 核心长相组件的周围运动是必不可少的,并且取决于PG合成和蛋白质相互作用.
- aPBP1a和MpgA的不同局部和动态表明它们在分裂过程中在糖体重塑中起着特殊的作用.
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