Elucidating the role of molecular chaperones in extremely thermophilic archaea, including the gamma prefoldin (γPFD) in the deep‐sea methanogen Methanocaldococcus jannaschii, is integral to understanding microbial adaptation to hot environments. This study focuses on genetically engineered knock‐out and overexpression strains to evaluate the importance of γPFD in the growth and thermal tolerance of M. jannaschii. An in‐depth analysis of cell growth, morphology and transcriptional responses to heat stress revealed that although the gene encoding γPFD is substantially upregulated in response to heat shock, the γPFD is not indispensable for high‐temperature survival. Instead, its absence in the knock‐out strain is compensated for by the upregulation of several proteolytic proteins in the absence of heat shock, nearly matching the corresponding transcription profile of selected transcripts for proteins involved in protein synthesis and folding in the wild‐type strain following heat shock, using quantitative reverse‐transcription PCR (RT‐qPCR). These findings bridge environmental adaptation with molecular biology, underscoring the versatility of extremophiles and providing a deeper mechanistic understanding of how they cope with stress.

中文翻译：

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丝状 γ-前折叠蛋白伴侣对于詹氏甲烷球菌的生长和热适应不是必需的


阐明分子伴侣在极端嗜热古菌中的作用，包括深海产甲烷菌詹纳斯基甲烷球菌中的γ前折叠蛋白（γPFD）的作用，对于了解微生物对热环境的适应至关重要。本研究重点关注基因工程敲除和过表达菌株，以评估 γPFD 在 M. jannaschii 生长和耐热性中的重要性。对细胞生长、形态和转录对热应激反应的深入分析表明，虽然编码γPFD的基因在热休克反应中显着上调，但γPFD对于高温生存并不是必不可少的。相反，它在敲除菌株中的缺失是通过在没有热激的情况下几种蛋白水解蛋白的上调来补偿的，几乎与野生型菌株中参与蛋白质合成和折叠的蛋白质的选定转录物的相应转录谱相匹配热休克后，使用定量逆转录 PCR (RT-qPCR)。这些发现将环境适应与分子生物学联系起来，强调了极端微生物的多功能性，并为它们如何应对压力提供了更深入的机制理解。