Heterologous expression of a rice RNA-recognition motif gene OsCBP20 in Escherichia coli confers abiotic stress tolerance

Diverse RNA-binding proteins (RBPs) have been determined to play a crucial role in post-transcriptional regulation of RNA metabolism during plant response to abiotic stresses. In this report we characterize a rice (Oryza sativa L.) protein, named OsCBP20, which is similar to subunits of a nuclear cap-binding protein 20 (CBP20), it contains a canonical RNA recognition motif (RRM). We compared the survivability of Escherichia coli (BL21) cells transformed with a recombinant plasmid with control E. coli under different concentration NaCl and mannitol. In addition, we also investigated the high temperature (50°C) impact on survival of E. coil. The OsCBP20 gene was isolated from rice (Oryza sativa L.) cDNA, encoding protein of 243 amino acids with a calculated molecular mass of 28.6 KDa and a PI of 5.14. On the basis of multiple sequence alignment and phylogenetic analysis, OsCBP20 is classified in RRM family. Recombinant OsCBP20 protein can be highly expressed in E. coli. The OsCBP20 protein can enhance the tolerance of E. coli recombinant to high salinity, heat, and dehydration, which suggested that OsCBP20 protein, may play a protective role under stressed conditions. Our work provides new evidence on CBP20 response to abiotic stresses.