Molecular cloning and expression analysis of receptor for activated C kinase 1 (HcRACK1) from Hyriopsis cumingii

In the present study, full length cDNA sequence of receptor for activated C kinase 1 gene of Hyriopsis cumingii(HcRACK1) was cloned by using 3'RACE and 5'RACE techniques, and the sequence and structural analysis of the HcRACK1 gene was conducted by using bioinformatics method. The results showed that the full-length cDNA of HcRACK1 consisted of 1249 bp in length, containing an open reading frame (ORF) of 957 bp encoding 318 amino acids. Analysis of protein domain features showed that the deduced polypeptide contained seven WD40 domains characteristic of RACK1 protein family. The tissue distribution of HcRACK1 in unchallenged H. cumingii and temporal expression pattern of HcRACK1 challenged with bacteria and exposed to 100 μg/L cadmium were analyzed by quantitative real-time PCR (qRT-PCR). The transcript was detected in all tissues tested, and the expression level was the highest in adductor muscle. After challenge with bacteria, expression level of HcRACK1 in haemocytes was gradually increased and until 24 h post challenge reached the peak. After exposure to cadmium, its expression level in digestive gland gradually increased and reached the peak on 3 d post exposure, and in haemocytes on 2 d post exposure, and then increased over time. It showed no obvious change in gill. These results suggested that HcRACK1 was related to the oxidative stress response caused by bacterial challenge and cadmium exposure, and it also has a potential link with organism's immune response.