Pastor Mar Martinez, Darnell Cynthia L, Vreugdenhil Angie, Schmid Amy K
Department of Biology, Duke University, Durham, NC 27708.
Mol Biol Cell. 2025 Jul 1;36(7):ar86. doi: 10.1091/mbc.E24-11-0505. Epub 2025 May 21.
For microbial cells, an appropriate response to changing environmental conditions is critical for viability. Transcription regulatory proteins, or transcription factors (TF) sense environmental signals to change gene expression. However, it remains unclear how TFs and their corresponding gene regulatory networks are selected over evolutionary time scales. The function of TFs and how they evolve are particularly understudied in archaeal organisms. Here, we identified, characterized, and compared the function of the RosR TF across three related hypersaline-adapted archaeal model species. RosR was previously characterized as a global regulator of gene expression during oxidative stress in the species (RosR). Here, we use functional genomics and quantitative phenotyping to demonstrate that, despite strong sequence conservation of RosR across species, its function diverges substantially. Surprisingly, RosR in (RosR) and (RosR) regulates genes whose products function in motility and the membrane, leading to significant defects in motility when is deleted. Given weak conservation and degeneration in cis-regulatory sequences recognized by the RosR TF across species, we hypothesize that the RosR regulatory network is readily rewired during evolution across related species of archaea.
对于微生物细胞而言，对不断变化的环境条件做出适当反应对其生存能力至关重要。转录调节蛋白，即转录因子（TF），感知环境信号以改变基因表达。然而，目前尚不清楚在进化时间尺度上如何选择转录因子及其相应的基因调控网络。在古生菌中，转录因子的功能及其进化方式尤其未得到充分研究。在此，我们鉴定、表征并比较了三种相关的适应高盐环境的古生菌模型物种中RosR转录因子的功能。RosR先前被表征为该物种（RosR）在氧化应激期间基因表达的全局调节因子。在此，我们使用功能基因组学和定量表型分析来证明，尽管RosR在不同物种间具有很强的序列保守性，但其功能却有很大差异。令人惊讶的是，（RosR）和（RosR）中的RosR调节其产物在运动性和膜功能方面发挥作用的基因，当缺失时会导致运动性出现显著缺陷。鉴于RosR转录因子在不同物种间识别的顺式调控序列的保守性较弱且存在退化现象，我们推测RosR调控网络在相关古生菌物种的进化过程中很容易发生重排。
