National Engineering Research Center of Tree Breeding and Ecological Restoration, State Key Laboratory of Efficient Production of Forest Resources, College of Biological Sciences and Technology, Beijing Forestry University, Beijing 100083, China.
Mol Biol Evol. 2024 Jul 3;41(7). doi: 10.1093/molbev/msae145.
Filamentous temperature-sensitive Z (FtsZ) is a tubulin-like GTPase that is highly conserved in bacteria and plants. It polymerizes into a ring at the division site of bacteria and chloroplasts and serves as the scaffold protein of the division complex. While a single FtsZ is present in bacteria and cyanobacteria, there are two subfamilies, FtsZ1 and FtsZ2 in the green lineage, and FtsZA and FtsZB in red algae. In Arabidopsis thaliana, the C-terminal motifs of AtFtsZ1 (Z1C) and AtFtsZ2-1 (Z2C) display distinct functions in the regulation of chloroplast division. Z1C exhibits weak membrane-binding activity, whereas Z2C engages in the interaction with the membrane protein AtARC6. Here, we provide evidence revealing the distinct traits of the C-terminal motifs of FtsZ1 and FtsZ2 throughout the plant evolutionary process. In a range of plant species, the C-terminal motifs of FtsZ1 exhibit diverse membrane-binding properties critical for regulating chloroplast division. In chlorophytes, the C-terminal motifs of FtsZ1 and FtsZ2 exhibit both membrane-binding and protein interaction functions, which are similar to those of cyanobacterial FtsZ and red algal FtsZA. During the transition from algae to land plants, the functions of the C-terminal motifs of FtsZ1 and FtsZ2 exhibit differentiation. FtsZ1 lost the function of interacting with ARC6 in land plants, and the membrane-binding activity of FtsZ2 was lost in ferns. Our findings reveal the functional differentiation of the C-terminal motifs of FtsZs during plant evolution, which is critical for chloroplast division.
丝状温度敏感 Z（FtsZ）是一种在细菌和植物中高度保守的微管蛋白 GTPase。它在细菌和叶绿体的分裂部位聚合形成环，作为分裂复合物的支架蛋白。虽然单个 FtsZ 存在于细菌和蓝藻中，但在绿色谱系中有两个亚家族，FtsZ1 和 FtsZ2，而在红藻中有 FtsZA 和 FtsZB。在拟南芥中，AtFtsZ1（Z1C）和 AtFtsZ2-1（Z2C）的 C 端基序在调节叶绿体分裂方面显示出不同的功能。Z1C 表现出较弱的膜结合活性，而 Z2C 与膜蛋白 AtARC6 相互作用。在这里，我们提供了证据，揭示了 FtsZ1 和 FtsZ2 的 C 端基序在整个植物进化过程中的不同特征。在一系列植物物种中，FtsZ1 的 C 端基序表现出多样化的膜结合特性，对于调节叶绿体分裂至关重要。在绿藻中，FtsZ1 和 FtsZ2 的 C 端基序既具有膜结合功能，也具有蛋白质相互作用功能，这与蓝藻的 FtsZ 和红藻的 FtsZA 相似。在从藻类到陆生植物的过渡过程中，FtsZ1 和 FtsZ2 的 C 端基序的功能发生了分化。FtsZ1 在陆生植物中失去了与 ARC6 相互作用的功能，而 FtsZ2 的膜结合活性在蕨类植物中丧失。我们的发现揭示了 FtsZs 的 C 端基序在植物进化过程中的功能分化，这对于叶绿体分裂至关重要。
