Cold shock domains (CSD) (PF00313) are proteins that help acclimate cells to colder growth conditions. The CSD is among the most ancient and well conserved nucleic acid binding domains, shown in prokaryotes, higher plants, and animals. The major cold shock protein of Escherichia coli, CspA, produced upon a rapid downshift in growth temperature, is involved in the transcriptional regulation of at least two genes. The protein shares high homology with the nucleic acid-binding domain of the Y-box factors, a family of eukaryotic proteins involved in transcriptional and translational regulation (Schindelin et al., 1994).

Plant CSD homologues typically contain two distinct nucleic acid-binding modules, a single N-terminal CSD and variable quantities of C-terminal CCHC zinc fingers, which are interspersed by glycine-rich regions, and have been shown to bind ssDNA, dsDNA, and ssRNA. Functionally, CSPs are generally considered to help cell survival at low temperatures by destabilizing RNA secondary structures (Sasaki et al., 2012, Yan et al., 2022). Wheat cold shock protein 1 (WCSP1) has been shown to suppress transcription termination at low temperatures, as well as melt DNA to ensure efficient transcription at low temperatures (PMID:16788067; PMID:20060550). OsCSP1 and OsCSP2 (Oryza sativa CSD protein) encode putative proteins consisting of an N-terminal CSD and glycine-rich regions that are interspersed by 4 and 2 CX(2)CX(4)HX(4)C (CCHC) retroviral-like zinc fingers, respectively. Both OsCSP transcripts are transiently up-regulated in response to low-temperature stress and rapidly return to a basal level of gene expression (Chaikham et al., 2008).

There are at least 4 CSD domain proteins in maize. A commercial transgenic variety of maize named “DroughtGard” maize was developed through constitutive expression of the cold shock protein B (CSPB) from Bacillus subtilis to improve performance of maize (Zea mays) under water-limited conditions (Wang et al., 2015). In cotton, overexpression of DgCspC from Deinococcus gobiensis, promoted plant growth, as exhibited by larger leaf size and higher plant height than the wild-type plants and transgenic cotton lines showed higher tolerance to drought and salts stresses than wild-type plants (Xia et al., 2022).

Last updated June 2023 by John Gray

References:

Chaikam V, Karlson D. Functional characterization of two cold shock domain proteins from Oryza sativa. Plant Cell Environ. 2008 Jul;31(7):995-1006. doi: 10.1111/j.1365-3040.2008.01811.x. Epub 2008 Apr 7. PMID: 18397370.

Schindelin H, Jiang W, Inouye M, Heinemann U. Crystal structure of CspA, the major cold shock protein of Escherichia coli. Proceedings of the National Academy of Sciences of the United States of America. 1994 May;91(11):5119-5123. DOI: 10.1073/pnas.91.11.5119. PMID: 8197194; PMCID: PMC43943

Wang C, Burzio LA, Koch MS, Silvanovich A, Bell E. Purification, characterization and safety assessment of the introduced cold shock protein B in DroughtGard maize. Regul Toxicol Pharmacol. 2015 Mar;71(2):164-73. doi: 10.1016/j.yrtph.2014.12.014. Epub 2014 Dec 27. PMID: 25545317.

Yan Y, Gan J, Tao Y, Okita TW, Tian L. RNA-Binding Proteins: The Key Modulator in Stress Granule Formation and Abiotic Stress Response. Front Plant Sci. 2022 Jun 15;13:882596. doi: 10.3389/fpls.2022.882596. PMID: 35783947; PMCID: PMC9240754.

Sasaki K, Imai R. Pleiotropic roles of cold shock domain proteins in plants. Front Plant Sci. 2012 Jan 19;2:116. doi: 10.3389/fpls.2011.00116. PMID: 22639630; PMCID: PMC3355641.

Xia W, Zong J, Zheng K, Wang Y, Zhang D, Guo S, Sun G. DgCspC gene overexpression improves cotton yield and tolerance to drought and salt stress comparison with wild-type plants. Front Plant Sci. 2022 Sep 6;13:985900. doi: 10.3389/fpls.2022.985900. PMID: 36147229; PMCID: PMC9485673.