Molecular Biology Division, Bhabha Atomic Research Centre, Mumbai 400085, India; Homi Bhabha National Institute, Training School Complex, Anushakti Nagar, Mumbai 400094, India.
Molecular Biology Division, Bhabha Atomic Research Centre, Mumbai 400085, India.
Biochim Biophys Acta Proteins Proteom. 2019 Feb;1867(2):98-106. doi: 10.1016/j.bbapap.2018.10.015. Epub 2018 Oct 30.
An extremophile D. radiodurans encodes a non-cold shock inducible cold shock protein homolog DR_0907 (also known as PprM). The DR_0907 ORF was deleted by knockout mutagenesis and the resultant deletion mutant (ΔpprM D. radiodurans) displayed growth defect as well as gamma-radiation sensitivity (D values = ΔpprM D. radiodurans: 12.1 kGy versus wild type (WT) D. radiodurans: 14 kGy). 2D gel based comparative proteomics revealed a comparable induction of DNA repair proteins in ΔpprM D. radiodurans and WT D. radiodurans recovering from 5 kGy gamma irradiation (Co gamma source, dose rate: 2 kGy/h), suggesting that pprM does not cause radiation sensitivity through modulation of DdrO-regulated DNA repair genes. However, deletion of pprM did result in repression of several proteins that belonged to vital housekeeping pathways such as metabolism and protein homeostasis that might contribute to slow growth phenotype. These deficiencies intrinsic to ΔpprM D. radiodurans might also contribute to its radiation sensitivity.
一种耐极端环境的 D. radiodurans 编码了一种非冷休克诱导的冷休克蛋白同源物 DR_0907(也称为 PprM)。通过敲除诱变缺失了 DR_0907 ORF,所得缺失突变体(ΔpprM D. radiodurans)表现出生长缺陷和γ辐射敏感性(D 值=ΔpprM D. radiodurans:12.1 kGy,而野生型(WT)D. radiodurans:14 kGy)。基于 2D 凝胶的比较蛋白质组学揭示了在从 5 kGy γ辐射中恢复的ΔpprM D. radiodurans 和 WT D. radiodurans 中,DNA 修复蛋白的诱导相当(Co 伽马源,剂量率:2 kGy/h),这表明 pprM 并未通过调节 DdrO 调节的 DNA 修复基因导致辐射敏感性。然而,pprM 的缺失确实导致了几个属于重要的管家途径的蛋白质的抑制,如代谢和蛋白质稳态,这可能导致生长缓慢的表型。ΔpprM D. radiodurans 固有的这些缺陷也可能导致其对辐射敏感。