696 / 2019-05-01 15:58:38

RNA chaperone function of Universal Stress Protein (AtUSP) is important to cold stress tolerance in Arabidopsis thaliana

DNA and RNA-binding activity,cold stress,RNA chaperone

全体主题 > Abiotic Stress

To clarify the functional roles of universal stress protein in Arabidopsis, AtUSP, we confirmed its mRNA expression under cold stress conditions in wild type. The transcript level of AtUSP is increased. These results suggest that AtUSP has a crucial role in cold stress tolerance. By constructing the T-DNA inserted knock-out mutant (atusp) and its overexpression (AtUSP-OE) plants, we analyzed the physiological responses against environmental stresses. From these comparisons, AtUSP-OE plants tolerance to cold stress in contrast to atusp. And we found that AtUSP is localized in both nucleus and cytoplasm and critically affects RNA metabolism-related functions. From the study, we found that AtUSP can bind nucleic acids including single/double stranded-DNA and luciferase mRNA analyzed in agarose gels. And AtUSP protein also showed a strong nucleic acid-melting activity. The expression of AtUSP in RL211 E. coli containing a hairpin-loop structured RNA at the upstream of chloramphenicol acetyltransferase (CAT) gene exhibited an anti-termination activity for CAT gene expression. Furthermore, expression of AtUSP in cold-sensitive E. coli mutant (BX04) complemented the cold sensitivity of the mutant cells. Since these properties are typical characteristics of RNA chaperones. From all these data, it can be concluded that AtUSP functions as an RNA chaperone in cold stress conditions. Thus, the RNA chaperone functions of AtUSP enhanced tolerance to cold stress.