The Cyanobacterial Ribosomal-Associated Protein LrtA Is Involved in Post-Stress Survival in Synechocystis sp PCC 6803
The Cyanobacterial Ribosomal-Associated Protein LrtA Is Involved in Post-Stress Survival in Synechocystis sp PCC 6803
复制标题
DOI：
10.1371/journal.pone.0159346
复制
发表时间：
2016-07-21
期刊：
影响因子：
3.7
通讯作者：
Muro-Pastor, M. Isabel
中科院分区：
文献类型：
--
作者：
Galmozzi, Carla V.;Florencio, Francisco J.;Muro-Pastor, M. Isabel
光抑制转录本编码蓝藻中的LrtA蛋白。我们发现，半衰期lrtA转录集胞藻属PCC 6803是更高的黑暗处理的细胞相比，光生长的细胞，这表明转录后控制lrtA的表达。lrtA 5非翻译前导区参与了这种黑暗依赖性调节。我们还发现集胞藻PCC 6803 LrtA是一种核糖体相关蛋白，存在于30S和70S核糖体颗粒中。为了研究该蛋白的功能，我们构建了lrtA基因的缺失突变体。缺乏LrtA（lrtA）的细胞具有显著较低量的70S颗粒和较大量的30S和50S颗粒，表明LrtA在稳定70S颗粒中的作用。具有不同量LrtA蛋白的集胞藻菌株：野生型、。lrtA和LrtAS（过表达lrtA）在标准实验室条件下的生长速率没有差异。然而，在抗生素泰乐菌素存在下观察到明显的LrtA剂量依赖性效应，LrtAS菌株最敏感。在山梨醇引起的高渗胁迫下也得到了类似的结果。相反，在长时间的饥饿之后，相对于野生型和LrtAS菌株，lrtA菌株的生长延迟。提出了LrtA蛋白在应激后存活中的积极作用。
A light-repressed transcript encodes the LrtA protein in cyanobacteria. We show that half-life of lrtA transcript from Synechocystis sp. PCC 6803 is higher in dark-treated cells as compared to light-grown cells, suggesting post-transcriptional control of lrtA expression. The lrtA 5 untranslated leader region is involved in that darkness-dependent regulation. We also found that Synechocystis sp. PCC 6803 LrtA is a ribosome-associated protein present in both 30S and 70S ribosomal particles. In order to investigate the function of this protein we have constructed a deletion mutant of the lrtA gene. Cells lacking LrtA (lrtA) had significantly lower amount of 70S particles and a greater amount of 30S and 50S particles, suggesting a role of LrtA in stabilizing 70S particles. Synechocystis strains with different amounts of LrtA protein: wild-type,. lrtA, and LrtAS (overexpressing lrtA) showed no differences in their growth rate under standard laboratory conditions. However, a clear LrtA dose-dependent effect was observed in the presence of the antibiotic tylosin, being the LrtAS strains the most sensitive. Similar results were obtained under hyperosmotic stress caused by sorbitol. Conversely, after prolonged periods of starvation,. lrtA strains were delayed in their growth with respect to the wild-type and the LrtAS strains. A positive role of LrtA protein in post-stress survival is proposed.