期刊
出版社
NATL ACAD SCIENCES
DOI: 10.1073/pnas.2211789119
关键词
UV radiation; cyanobacteria; fitness; leucyl aminopeptidase; RB-TnSeq
资金
- National Science Foundation through the University of California, San Diego Materials Research Science and Engineering Center [DMR-2011924]
- Graduate Research Fellowship Program (GRFP) [DGE-1650112]
- National Institute of General Medical Sciences of the NIH [R35GM118290]
This study evaluates the genes that affect the tolerance of cyanobacteria to UV radiation and highlights the importance of genes involved in DNA repair, glutathione synthesis, and the assembly and maintenance of photosystem II. The disruption of a gene encoding leucyl aminopeptidase (LAP) shows the greatest decrease in UV-specific fitness.
UV radiation (UVR) has significant physiological effects on organisms living at or near the Earth's surface, yet the full suite of genes required for fitness of a photosynthetic organism in a UVR-rich environment remains unknown. This study reports a genome-wide fitness assessment of the genes that affect UVR tolerance under environmentally relevant UVR dosages in the model cyanobacterium Synechococcus elongatus PCC 7942. Our results highlight the importance of specific genes that encode proteins involved in DNA repair, glutathione synthesis, and the assembly and maintenance of photosystem II, as well as genes that encode hypothetical proteins and others without an obvious connection to canonical methods of UVR tolerance. Disruption of a gene that encodes a leucyl aminopeptidase (LAP) conferred the greatest UVR-specific decrease in fitness. Enzymatic assays demonstrated a strong pH-dependent affinity of the LAP for the dipeptide cysteinyl-glycine, suggesting an involvement in glutathione catabolism as a function of night-time cytosolic pH level. A low differential expression of the LAP gene under acute UVR exposure suggests that its relative importance would be overlooked in transcript-dependent screens. Subsequent experiments revealed a similar UVR-sensitivity phenotype in LAP knockouts of other organisms, indicating conservation of the functional role of LAPs in UVR tolerance.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据