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

在过去的几十年里，我们对古生菌的多样性、进化以及新陈代谢和运动等过程的了解大大增加。然而，就细菌而言，许多其他基本的细胞过程在很大程度上仍未得到充分研究。近年来，人们对古细菌的分裂过程进行了更详细的研究。大多数古生菌通过利用细菌微管蛋白同源物FtsZ的同源物进行二元裂变分裂。有趣的是，古生菌可以有一个或两个FtsZ蛋白，这表明古生菌内的细胞分裂存在多样性。最近的研究进一步确定了古细菌细胞分裂的关键因素，如固定z环的SepF蛋白。此外，细菌分裂体的大部分成分在古细菌中是不存在的。本项目将以史密斯甲烷杆菌（Methanobrevibacter smithii）和火山盐铁菌（Haloferax volcanii）分别作为古菌模型，分别在一个或两个ftsz驱动下进行细胞分裂，研究古菌细胞分裂的新参与者。我们将研究PRC-barrel蛋白的作用，这是一个广泛分布于古细菌中的未知家族，可能参与了H. volcanii的细胞分裂。同时，我们将通过识别FtsZ和SepF的伙伴并分析它们特定的MreB同源物的作用来表征M. smithii可分子的其他成分。我们将采用跨学科的方法，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。总之，在这个项目中获得的结果将从根本上推进我们对古细菌细胞分裂过程的认识，有助于我们对它们的起源和进化的理解。

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.