Translation elongation factors (EFs) are proteins that play important roles during the elongation stage of protein synthesis. In prokaryotes, at least four EFs function in repetitive reactions (EF-Tu, EF-Ts, EF-G, and EF-P). EF-P plays a vital role in the specialized translation of consecutive proline amino acid motifs. It was also recently recognized that EF-P acts throughout translation elongation. Here, we demonstrated for the first time that cell division and morphology are intimately linked to the control of EF-P in the model cyanobacterium Synechococcus elongatus PCC7942. We constructed the overexpression of a wild-type gene product for EF-P (Synpcc7942_2565) as a tool to identify EF-P functionality. The overexpression of EF-P resulted in the morphological plasticity of hyperelongated cells. During the stationary phase, EF-P overexpressors displayed cell lengths of 150 μm or longer, approximately 35 times longer than the control. Total cellular protein and amino acid content were also increased in overexpressors. To explore the molecular mechanisms underlying hyperelongation, gene expression analysis was performed. The results revealed that cell division genes, including ftn6, minD, mreB, mreC, and ftsZ, were modulated in overexpressors. Strikingly, ftn6 was severely down-regulated. Little is known regarding EF-P in prokaryotic photosynthetic organisms. Our results suggest that cyanobacterial EF-P participates in the acceleration of protein synthesis and also regulates cell division processes. These findings suggest new ways to modify translation and metabolism in cyanobacteria. Phenotypic and metabolic alterations caused by overexpressing EF-P may also be beneficial for applications such as low-cost, green molecular factories. KEY POINTS: • Cell division and cell morphology in the cyanobacterium Synechococcus elongatus PCC7942 are closely linked with the control of translation elongation factor P (EF-P). • Overexpression of EF-P leads to morphological plasticity in hyperelongated cells. • Cyanobacterial EF-P is involved in the acceleration of protein synthesis and the regulation of cell division processes.

中文翻译：

---

在延伸的Synchococcus elongatus PCC7942中翻译延伸因子P的过表达引起的超延伸细胞的形态可塑性。

翻译延伸因子（EFs）是在蛋白质合成的延伸阶段起重要作用的蛋白质。在原核生物中，至少有四个EF在重复反应中起作用（EF-Tu，EF-T，EF-G和EF-P）。EF-P在连续脯氨酸氨基酸基序的专业翻译中起着至关重要的作用。最近还认识到，EF-P在翻译延伸过程中始终起作用。在这里，我们首次证明了细胞分裂和形态与模型蓝藻Synchococcus elongatus PCC7942中EF-P的控制密切相关。我们构建了针对EF-P的野生型基因产物（Synpcc7942_2565）的过表达，作为鉴定EF-P功能的工具。EF-P的过度表达导致超伸长细胞的形态可塑性。在固定阶段，EF-P过表达细胞显示的细胞长度为150μm或更长，约为对照的35倍。在过表达者中，总细胞蛋白和氨基酸含量也增加。为了探索潜在的过度伸长的分子机制，进行了基因表达分析。结果表明，细胞分裂基因，包括ftn6，minD，mreB，mreC和ftsZ，在过表达基因中得到调节。令人惊讶的是，ftn6被严重下调。关于原核生物光合生物中的EF-P知之甚少。我们的结果表明，蓝细菌EF-P参与蛋白质合成的加速，并调节细胞分裂过程。这些发现提示了在蓝细菌中修饰翻译和代谢的新方法。由过表达EF-P引起的表型和代谢变化也可能有益于低成本绿色分子工厂等应用。要点：•蓝藻延伸乳突球菌PCC7942中的细胞分裂和细胞形态与翻译延伸因子P（EF-P）的控制密切相关。•EF-P的过表达导致超伸长细胞的形态可塑性。•蓝细菌EF-P参与蛋白质合成的加速和细胞分裂过程的调节。•EF-P的过表达导致超伸长细胞的形态可塑性。•蓝细菌EF-P参与蛋白质合成的加速和细胞分裂过程的调节。•EF-P的过表达导致超伸长细胞的形态可塑性。•蓝细菌EF-P参与蛋白质合成的加速和细胞分裂过程的调节。