National Laboratory of Biomacromolecules, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China.
University of Chinese Academy of Sciences, Beijing 100049, China.
Nat Commun. 2017 Jul 6;8:15979. doi: 10.1038/ncomms15979.
Lipid droplets (LDs) are multi-functional organelles consisting of a neutral lipid core surrounded by a phospholipid monolayer, and exist in organisms ranging from bacteria to humans. Here we study the functions of LDs in the oleaginous bacterium Rhodococcus jostii. We show that these LDs bind to genomic DNA through the major LD protein, MLDS, which increases survival rate of the bacterial cells under nutritional and genotoxic stress. MLDS expression is regulated by a transcriptional regulator, MLDSR, that binds to the operator and promoter of the operon encoding both proteins. LDs sequester MLDSR, controlling its availability for transcriptional regulation. Our findings support the idea that bacterial LDs can regulate nucleic acid function and facilitate bacterial survival under stress.
脂滴(LDs)是由中性脂质核心被磷脂单层包围而成的多功能细胞器,存在于从细菌到人类等各种生物体中。在这里,我们研究了产油细菌 Rhodococcus jostii 中的 LDs 的功能。我们发现,这些 LDs 通过主要的 LD 蛋白 MLDS 与基因组 DNA 结合,这增加了细菌细胞在营养和遗传毒性应激下的存活率。MLDS 的表达受转录调节因子 MLDSR 调控,后者与编码这两种蛋白的操纵子的操纵子和启动子结合。LDs 将 MLDSR 隔离,控制其可用于转录调节。我们的发现支持了这样一种观点,即细菌 LDs 可以调节核酸功能,并促进细菌在应激下的生存。