Cloning and prokaryotic expression of HSP90β cDNA sequence of an Antarctic iecfish Chionodraco hamatus

Abstract:

In order to testify the correlations between Antarctic fish HSP90β protein and coldness adaptation, we cloned the complete open reading frame of the HSP90β gene from an Antarctic icefish, Chionodraco hamatus and investigated the prokaryotic expression of C. hamatus-HSP90β protein under cold stresses. As a control, the ORF of Oreochromis niloticus HSP90β was also cloned. Results showed that the coding region of C. hamatus HSP90β gene is 2184 bp in length, encoding 728 amino acids. Multiple sequence alignment results showed that C. hamatus HSP90β shared more than 87% identities with other fishes. Protein domain analysis showed that C. hamatus HSP90β possessed the conserved domain of the HSP90 family, and showed highly conserved in the important functional site. Recombinant pET28-CH-HSP90 and pET28-ON-HSP90 prokaryotic expression plasmids were constructed and expressed in Escherichia coli to testify the function of C. hamatus HSP90β under 4℃ stress. Results showed that the survival rate of C. hamatus-HSP90β group was significantly higher than that of the O.niloticus-HSP90β and the control group. Our results indicated that C. hamatus HSP90β protein possessed more remarkable protective effects against cold stress and HSP90β protein might be involved in cold adaptation physiological process in C. hamatus.