Shrivastava Alok K, Pandey Sarita, Yadav Shivam, Mishra Yogesh, Singh Prashant K, Rai Ruchi, Singh Shilpi, Rai Snigdha, Rai L C
Molecular Biology Section, Centre of Advanced Study in Botany, Institute of Science, Banaras Hindu University, Varanasi 221005, India.
J Proteomics. 2016 May 17;140:81-99. doi: 10.1016/j.jprot.2016.04.004. Epub 2016 Apr 15.
Alkylhydroperoxide reductase (AhpC), a 1-Cys peroxiredoxin is well known for maintaining the cellular homeostasis. Present study employs proteome approach to analyze and compare alterations in proteome of Anabaena PCC7120 in overexpressing (An+ahpC), deletion (An∆ahpC) and its wild type. 2-DE based analysis revealed that the major portion of identified protein belongs to energy metabolism, protein folding, modification and stress related proteins and carbohydrate metabolism. The two major traits discernible from An+ahpC were (i) augmentation of photosynthesis and nitrogen fixation (ii) modulation of regulatory network of antioxidative proteins. Increased accumulation of proteins of light reaction, dark reaction, pentose phosphate pathway and electron transfer agent FDX for nitrogenase in An+ahpC and their simultaneous downregulation in AnΔahpC demonstrates its role in augmenting photosynthesis and nitrogen fixation. Proteomic data was nicely corroborated with physiological, biochemical parameters displaying upregulation of nitrogenase (1.6 fold) PSI (1.08) and PSII (2.137) in An+ahpC. Furthermore, in silico analysis not only attested association of AhpC with peroxiredoxins but also with other players of antioxidative defense system viz. thioredoxin and thioredoxin reductase. Above mentioned findings are in agreement with 33-40% and 40-60% better growth performance of An+ahpC over wild type and An∆ahpC respectively under abiotic stresses, suggesting its role in maintenance of metabolic machinery under stress.
Present work explores key role of AhpC in mitigating stress in Anabaena PCC7120 through combined proteomic, biochemical and in silico investigations. This study is the first attempt to analyze and compare alterations in proteome of Anabaena PCC7120 following addition (overexpressing strain An+ahpC) and deletion (mutant An∆ahpC) of AhpC against its wild type. The effort resulted in two major traits in An+ahpC as (i) augmentation of photosynthesis and nitrogen fixation (ii) modulation of regulatory network of antioxidative proteins.
烷基过氧化氢还原酶（AhpC）是一种1-半胱氨酸过氧化物酶，以维持细胞内稳态而闻名。本研究采用蛋白质组学方法分析和比较了鱼腥藻PCC7120过表达株（An+ahpC）、缺失株（An∆ahpC）及其野生型的蛋白质组变化。基于双向电泳的分析表明，鉴定出的蛋白质主要属于能量代谢、蛋白质折叠、修饰和应激相关蛋白以及碳水化合物代谢。An+ahpC中可识别的两个主要特征是：（i）光合作用和固氮作用增强；（ii）抗氧化蛋白调控网络的调节。An+ahpC中光反应、暗反应、磷酸戊糖途径和固氮酶电子传递剂FDX的蛋白质积累增加，而在AnΔahpC中它们同时下调，这证明了其在增强光合作用和固氮作用中的作用。蛋白质组学数据与生理生化参数得到了很好的印证，显示An+ahpC中固氮酶（1.6倍）、光系统I（1.08）和光系统II（2.137）上调。此外，计算机分析不仅证实了AhpC与过氧化物酶的关联，还证实了其与抗氧化防御系统的其他成分即硫氧还蛋白和硫氧还蛋白还原酶的关联。上述发现与An+ahpC在非生物胁迫下比野生型和An∆ahpC分别具有33 - 40%和40 - 60%更好的生长性能一致，表明其在胁迫下维持代谢机制中的作用。
本研究通过蛋白质组学、生化和计算机相结合的研究方法，探索了AhpC在减轻鱼腥藻PCC7120胁迫中的关键作用。本研究首次尝试分析和比较了在添加（过表达株An+ahpC）和缺失（突变株An∆ahpC）AhpC后，鱼腥藻PCC7120相对于其野生型的蛋白质组变化。研究结果显示An+ahpC有两个主要特征：（i）光合作用和固氮作用增强；（ii）抗氧化蛋白调控网络的调节。
