Characterization of T-complex polypeptide 1 (TCP-1) from the Chilo suppressalis HSP60 family and its expression in response to temperature stress

Many proteins require assistance from molecular chaperones at various stages to attain correctly folded states and functional conformations during protein synthesis. In this study, the gene encoding T-complex polypeptide 1 (TCP-1), which belongs to the heat shock protein 60 (HSP60) family, was isolated and characterized from the rice stem borer, Chilo suppressalis, by RACE and qPCR, respectively. The full-length cDNA of Tcp-1 was 2 144 bp and encoded a 1 635-bp ORF; the deduced translational product contained 545 amino acids with 5'- and 3'-UTRs and an isoelectric point of 5.29. Cluster analysis confirmed that the deduced amino acid sequence shared high identity (60-99%) with TCP-1 from other insects. To investigate Tcp-1 expression in response to abiotic stress, qPCR was used to analyze expression levels of Tcp-1 mRNA in C. suppressalis larvae exposed to temperatures ranging from -11 to 43°C. With respect to heat shock, Tcp-1 expression was higher than the control after a 2-h exposure to 30 and 36°C and declined at 39 and 43°C. Difference in Tcp-1 expression was observed at temperatures ranging from -11 to 27°C. qPCR analyses revealed that Tcp-1 expression was the highest in hindgut tissue as compared to heads, epidermis, fat body, foregut, midgut, and malpighian tubules. Our results indicated that Tcp-1 expression was differentially expressed in C. suppressalis tissues, and was impacted by temperature stress.