Molecular Cloning of the Calcyclin-Binding Protein Gene from the Swimming CrabPortunus trituberculatusand Its Roles in Salinity Stress Adaptation

Abstract

ABSTRACT The swimming crab Portunus trituberculatus is an important fishery and aquaculture species in China, and salinity has a significant effect on its physiological processes. To verify whether the calcyclin-binding protein (CacyBP) gene is related to salinity stress adaptation, a cDNA fragment of P. trituberculatus CacyBP was amplified and cloned. The cloned PtCacyBP fragment contains 702 nucleotides encoding 233 amino acids, with a calculated molecular weight of 26.35 kDa. PtCacyBP has approximately 40% amino acid sequence identity with homologs from other known species. To further validate the salinity tolerance roles of PtCacyBP. this study investigated the prokaryotic and eukaryotic expression of a PtCacyBP recombinant plasmid under a series of salinity stresses. A recombinant pET28(+)-PtCacyBP prokaryotic expression plasmid was constructed and expressed in Escherichia coli DE3 (BL21). Moreover, an EGFP-C2-PtCacyBP eukaryotic expression plasmid was constructed and transfected into 293T cells, whi...