Cerletti Micaela, Paggi Roberto A, Guevara Carina Ramallo, Poetsch Ansgar, De Castro Rosana E
Instituto de Investigaciones Biológicas, Universidad Nacional de Mar del Plata (UNMDP), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Funes 3250 4to nivel, Mar del Plata (7600), Argentina.
Plant Biochemistry, Ruhr University Bochum, 44801 Bochum, Germany.
J Proteomics. 2015 May 21;121:1-14. doi: 10.1016/j.jprot.2015.03.016. Epub 2015 Mar 27.
The membrane-associated LonB protease is essential for viability in Haloferax volcanii, however, the cellular processes affected by this protease in archaea are unknown. In this study, the impact of a lon conditional mutation (down-regulation) on H. volcanii physiology was examined by comparing proteomes of parental and mutant cells using shotgun proteomics. A total of 1778 proteins were identified (44% of H. volcanii predicted proteome) and 142 changed significantly in amount (≥2 fold). Of these, 66 were augmented in response to Lon deficiency suggesting they could be Lon substrates. The "Lon subproteome" included soluble and predicted membrane proteins expected to participate in diverse cellular processes. The dramatic stabilization of phytoene synthase (57 fold) in concert with overpigmentation of lon mutant cells suggests that Lon controls carotenogenesis in H. volcanii. Several hypothetical proteins, which may reveal novel functions and/or be involved in adaptation to extreme environments, were notably increased (300 fold). This study, which represents the first proteome examination of a Lon deficient archaeal cell, shows that Lon has a strong impact on H. volcanii physiology evidencing the cellular processes controlled by this protease in Archaea. Additionally, this work provides a platform for the discovery of novel targets of Lon proteases.
The proteome of a Lon-deficient archaeal cell was examined for the first time showing that Lon has a strong impact on H. volcanii physiology and evidencing the proteins and cellular processes controlled by this protease in Archaea. This work will facilitate future investigations aiming to address Lon function in archaea and provides a platform for the discovery of endogenous targets of the archaeal-type Lon as well as novel targets/processes regulated by Lon proteases. This knowledge will advance the understanding on archaeal physiology and the biological function of membrane proteases in microorganisms.
膜相关的LonB蛋白酶对于嗜盐栖热菌的生存至关重要，然而，古菌中受该蛋白酶影响的细胞过程尚不清楚。在本研究中，通过使用鸟枪法蛋白质组学比较亲本细胞和突变细胞的蛋白质组，研究了lon条件突变（下调）对嗜盐栖热菌生理学的影响。总共鉴定出1778种蛋白质（占嗜盐栖热菌预测蛋白质组的44%），其中142种蛋白质的含量发生了显著变化（≥2倍）。其中，66种蛋白质因Lon缺乏而增加，表明它们可能是Lon的底物。“Lon亚蛋白质组”包括预期参与多种细胞过程的可溶性和预测的膜蛋白。八氢番茄红素合酶的显著稳定（57倍）与lon突变细胞的色素过度沉着一致，表明Lon控制嗜盐栖热菌中的类胡萝卜素合成。几种可能揭示新功能和/或参与适应极端环境的假设蛋白显著增加（300倍）。这项首次对Lon缺陷古菌细胞进行蛋白质组检查的研究表明，Lon对嗜盐栖热菌生理学有强烈影响，证明了古菌中受该蛋白酶控制的细胞过程。此外，这项工作为发现Lon蛋白酶的新靶点提供了一个平台。
首次对Lon缺陷古菌细胞的蛋白质组进行了检查，表明Lon对嗜盐栖热菌生理学有强烈影响，并证明了古菌中受该蛋白酶控制的蛋白质和细胞过程。这项工作将促进未来旨在研究古菌中Lon功能的调查，并为发现古菌型Lon的内源性靶点以及由Lon蛋白酶调节的新靶点/过程提供一个平台。这些知识将推进对古菌生理学和微生物中膜蛋白酶生物学功能的理解。
