Recently, Dr. Zikang ZHOU and Prof. Hongzhi TANG from the School of Life Sciences and Biotechnology (SLSB), SJTU published a collaborative research article on Cell Discovery (2021, 7:1-12) online. Titled “A cold shock protein promotes high-temperature microbial growth through binding to diverse RNA species”, the research group revealed the molecular mechanism of the cold shock protein CspL facilitating cells growth in high-temperature environment.

The researchers found the global protective role of the cold chock protein CspL on RNA under cellular high-temperature stress. Microbial cells must maintain stable physiological and biochemical functions under various stress conditions. Elevated temperature disrupts the original intracellular homeostasis, interfering with normal physiological functions and altering cell structure. Improving microbial tolerance to high temperatures has potential applications, such as reducing the risk of contamination in open fermentations, and thus reducing production costs. A novel cold shock protein CspL derived from Bacillus coagulans 2-6 was identified in the excavation of high-temperature tolerant components, and it was confirmed that CspL binds mRNA and protects its conformation, which in turn promotes cell growth.

This research was supported by the National Key R&D Program of China (No. 2018YFA0901200) and the Shanghai Outstanding Academic Leaders Program (No. 20XD1421900). Dr. Zikang ZHOU and Prof. Hongzhi TANG are the co-first authors, and Prof. Hongzhi TANG is also the co-corresponding author of the paper. Several members of Prof. Linquan BAI’s team from SLSB, SJTU and Prof. Yuhui SUN’s team from Wuhan University also participated in the research.

RESEARCH ABSTRACT:

Endowing mesophilic microorganisms with high-temperature resistance is highly desirable for industrial microbial fermentation. Here, we report a cold-shock protein (CspL) that is an RNA chaperone protein from a lactate producing thermophile strain (Bacillus coagulans 2–6), which is able to recombinantly confer strong high-temperature resistance to other microorganisms. Transgenic cspL expression massively enhanced high-temperature growth of Escherichia coli (a 2.4-fold biomass increase at 45 °C) and eukaryote Saccharomyces cerevisiae (a 2.6-fold biomass increase at 36 °C). Importantly, we also found that CspL promotes growth rates at normal temperatures. Mechanistically, bio-layer interferometry characterized CspL’s nucleotide-binding functions in vitro, while in vivo we used RNA-Seq and RIP-Seq to reveal CspL’s global effects on mRNA accumulation and CspL’s direct RNA binding targets, respectively. Thus, beyond establishing how a cold-shock protein chaperone provides high-temperature resistance, our study introduces a strategy that may facilitate industrial thermal fermentation.