Exploration of new players in FtsZ-based cell DiVision in Archaea (DiVA)

在过去的几十年里，我们对古生代的多样性、进化和新陈代谢和运动性等过程的了解显著增加。然而，关于细菌，许多其他基本的细胞过程在很大程度上仍然没有得到充分的研究。近几年来，人们对古生界的分裂过程进行了较为详细的研究。大多数古生代通过使用细菌微管蛋白同系物FtsZ的同系物进行二次分裂来分裂。有趣的是，古生菌可能有一个或两个FtsZ蛋白，这表明古生菌内细胞质分裂的多样性。最近的研究发现了古生菌细胞分裂的更多关键元件，例如锚定Z环的SepF蛋白。此外，细菌分裂体的大部分成分在古菌中都不存在。在本项目中，史密斯甲烷短杆菌和火山嗜盐杆菌将分别作为由一个或两个FtsZ驱动的细胞质分裂的古生菌模型，以研究古生菌细胞分裂中的新角色。我们将研究PRC-Barrel蛋白的作用，这是一个在古生菌中广泛分布的未知家族，可能参与火山杆菌的细胞分裂。同时，我们将通过鉴定FtsZ和SepF的伴侣并分析他们特定的MreB同源基因的作用来表征史密斯分枝杆菌分裂体的其他成分。我们将应用一种跨学科的方法，包括突变体的表征、高分辨率荧光显微镜、结构生物学和生物信息学。综上所述，本项目取得的成果将从根本上提高我们对古生物细胞分裂过程的认识，有助于我们理解它们的起源和进化。

In the last decades, our knowledge about the diversity, evolution, and processes like for example metabolism and motility, in Archaea has increased significantly. Yet, with respect to Bacteria, many other fundamental cellular processes remain largely understudied. The process how Archaea divide has been studied in more detail in recent years. Most Archaea divide by binary fission using homologs of the bacterial tubulin homolog FtsZ. Intriguingly, archaea can have either one or two FtsZ proteins, suggesting a diversity in cytokinesis within Archaea. Recent studies have identified further key elements in archaeal cell division, such as the SepF protein that anchors the Z-ring. Moreover, most components of the bacterial divisome are absent in archaea. In this project, Methanobrevibacter smithii and Haloferax volcanii, will be used as archaeal models for cytokinesis driven by one or two FtsZs respectively, to study new players in archaeal cell division. We will study the role of PRC-barrel proteins, an uncharacterized family widely distributed in archaea and likely involved in cell division in H. volcanii. In parallel, we will characterize additional components of the M. smithii divisome by identifying the partners of FtsZ and SepF and analysing the role of their specific MreB homolog. We will apply an interdisciplinary approach involving the characterization of mutants, high-resolution fluorescent microscopy, structural biology, and bioinformatics. Together, the results obtained in this project will fundamentally advance our knowledge of the archaeal cell division processes, contributing to our understanding on their origin and evolution.