Pleiotropic Roles of Cold Shock Domain Proteins in Plants

Abstract

The cold shock domain (CSD) is a nucleic acid binding domain that is widely conserved from bacteria to higher plants and animals. In Escherichia coli, cold shock proteins (CSPs) are composed solely of a CSD and function as RNA chaperones that destabilize RNA secondary structures. Cellular RNAs tend to be folded into unfavorable structures under low temperature conditions, and RNA chaperones resolve these structures, recovering functionality of the RNAs. CSP functions are associated mainly with cold adaptation, but they are also involved in other biological processes under normal growth conditions. Eukaryotic CSD proteins contain auxiliary domains in addition to the CSD and regulate many biological processes such as development and stress tolerance. In plants, it has been demonstrated that CSD proteins play essential roles in acquiring freezing tolerance. In addition, it has been suggested that some plant CSD proteins regulate embryo development, flowering time, and fruit development. In this review, we summarize the pleiotropic biological functions of CSP proteins in plants and discuss possible mechanisms by which plant CSD proteins regulate the functions of RNA molecules.

Cold-Induced Cysts of the Photosynthetic DinoflagellateLingulodinium polyedrumHave an Arrested Circadian Bioluminescence Rhythm and Lower Levels of Protein Phosphorylation

“…It is possible, however, that CSPs do not function in cold adaptation in dinoflagellates but act as regulators of gene expression during normal growth. This is supported by the observation that CSPs in plants play a role in many cellular processes under standard growth conditions (Sasaki and Imai, 2012) as well as by the fact that Lingulodinium polyedrum in the cold prefers to slow down global metabolism by encysting rather than trying to maintain normal metabolism.…”

Arabidopsis COLD SHOCK DOMAIN PROTEIN 2 influences ABA accumulation in seed and negatively regulates germination

“…Plant CSD proteins contain an N-terminal CSD and a C-terminal glycine-rich region interspersed with various numbers of retroviral-like CCHC zinc fingers [4]. The first plant CSD protein characterized was wheat cold shock domain protein 1 (WCSP1), which accumulates in crown tissue during cold acclimation [12].…”

“…The cold shock domain (CSD) is a highly conserved nucleic acidbinding domain found in bacteria as well as animals and plants [1][2][3][4]. The CSD contains two consensus RNA binding motifs (RNP-1 and RNP2) that are essential for binding single-stranded DNA/ RNA [5,6].…”

An RNA chaperone, AtCSP2, negatively regulates salt stress tolerance

“…Arabidopsis thaliana has 4 genes that encode CSD proteins (AtCSP1 to AtCSP4). 22,25 Among them, AtCSP3 is the most extensively studied and its function in acquiring abiotic stress tolerance has been demonstrated. Compared with wild type, a knockout mutant of AtCSP3 is more sensitive to freezing, drought, and salt stresses.…”

“…[19][20][21] Plant CSD proteins typically contain a large glycine-rich region interspersed with CCHC zinc fingers as a C-terminal auxiliary domain. 22 The first characterized plant CSD protein was wheat cold shock protein 1 (WCSP1) which was identified as a cold-induced gene in winter wheat. 23 WCSP1 can melt doublestranded RNA/DNA and can complement a cold sensitive phenotype of an E. coli csp quadruple mutant.…”