HetF Protein Is a New Divisome Component in a Filamentous and Developmental Cyanobacterium.
HetF Protein Is a New Divisome Component in a Filamentous and Developmental Cyanobacterium.
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HetF 蛋白是丝状和发育蓝藻中的新分裂体成分
DOI：
10.1128/mbio.01382-21
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发表时间：
2021-08-31
期刊：
影响因子：
6.4
通讯作者：
Zhang CC
中科院分区：
文献类型：
--
作者：
Xing WY;Liu J;Wang ZQ;Zhang JY;Zeng X;Yang Y;Zhang CC
细菌细胞分裂，除了少数例外，是由FtsZ通过踩踏机制来重塑和收缩刚性肽聚糖（PG）层。然而，不同的生物体在细胞分裂复合体（分裂体）的组成上可能不同。在丝状蓝藻Anabaena sp.菌株PCC 7120中，hetF是异囊分化的起始条件，异囊是在联合氮剥夺下专门固定N2的细胞。在本研究中，我们证明了hetF在营养细胞中表达，并且在一定条件下是细胞分裂所必需的。在非允许条件下，ΔhetF突变体的细胞停止分裂，这与野生型在类似条件下HetF水平的增加一致。此外，HetF是一种位于细胞中间和细胞间连接处的膜蛋白。在没有HetF的情况下，FtsZ环仍然存在于伸长的细胞中；然而，PG重塑被废除。这种表型与室间隔PG合成酶FtsI的抑制相似。我们进一步揭示了HetF通过与FtsI相互作用被招募到分裂体或稳定在分裂体上，并且这种相互作用对于HetF在细胞分裂中的功能是必要的。我们的研究结果表明，HetF是一个主要依赖于光强的分裂体成员，并揭示了蓝藻中具有高度生态和环境重要性的细胞分裂机制的独特特征。
Bacterial cell division, with a few exceptions, is driven by FtsZ through a treadmilling mechanism to remodel and constrict the rigid peptidoglycan (PG) layer. Yet different organisms may differ in the composition of the cell division complex (divisome). In the filamentous cyanobacterium Anabaena sp. strain PCC 7120, hetF is required for the initiation of the differentiation of heterocysts, cells specialized in N2 fixation under combined-nitrogen deprivation. In this study, we demonstrate that hetF is expressed in vegetative cells and necessary for cell division under certain conditions. Under nonpermissive conditions, cells of a ΔhetF mutant stop dividing, consistent with increased levels of HetF under similar conditions in the wild type. Furthermore, HetF is a membrane protein located at midcell and cell-cell junctions. In the absence of HetF, FtsZ rings are still present in the elongated cells; however, PG remodeling is abolished. This phenotype is similar to that observed with the inhibition of the septal PG synthase FtsI. We further reveal that HetF is recruited to or stabilized at the divisome by interacting with FtsI and that this interaction is necessary for HetF function in cell division. Our results indicate that HetF is a member of the divisome depending mainly on light intensity and reveal distinct features of the cell division machinery in cyanobacteria that are of high ecological and environmental importance.