Yunyun Cheng1, Songcai Liu1,2, Chao Lu1, Qingyan Wu1, Siming Li1, Haoyu Fu1, Gang Wang1, Chen Lv1, Linyan Nie1, Yu Zhang1, Hao Yu1, Linlin Hao3. 1. College of Animal Science, Jilin University, 5333 Xi'an Road, Changchun, 130062, Jilin, China. 2. Five-Star Animal Health Pharmaceutical Factory of Jilin Province, 5333 Xi'an Road, Changchun, 130062, Jilin, China. 3. College of Animal Science, Jilin University, 5333 Xi'an Road, Changchun, 130062, Jilin, China. haolinlin@jlu.edu.cn.
Abstract
CONTEXT: In previous investigations, we have demonstrated the mutations in the signal peptide of porcine GH gene were associated with the body size. METHODS: In this study, the fusion gene expression vectors which consisted of eight signal peptide mutants of GH gene and EGFP gene were constructed according to three missense mutations (p.Val9Ala, p.Gln22Arg and p.Asp25Gly), and they were transfected into the GH3 cell line. RESULTS: The inhibition levels of EGFP gene transcriptions with different signal peptide mutants were significantly different. Typically, the allelic variants carrying Val in codon nine showed higher protein synthesis (P < 0.05), and the allelic variants carrying neutral Gln in codon 22 and Gly in codon 25 showed higher secretion proportion (P < 0.05) compared with the other groups as assessed by western blotting. In silico RNA folding prediction indicated that the mutations gave rise to different RNA secondary structures, suggesting that they might affect translation and protein synthesis. CONCLUSION: We conclude that the missense mutations within the signal sequence influence the expression and the secretion of the protein. To the best of our knowledge, this is the first report addressing the functional consequences of the mutations in the signal peptide of porcine GH gene.
CONTEXT: In previous investigations, we have demonstrated the mutations in the signal peptide of porcine GH gene were associated with the body size. METHODS: In this study, the fusion gene expression vectors which consisted of eight signal peptide mutants of GH gene and EGFP gene were constructed according to three missense mutations (p.Val9Ala, p.Gln22Arg and p.Asp25Gly), and they were transfected into the GH3 cell line. RESULTS: The inhibition levels of EGFP gene transcriptions with different signal peptide mutants were significantly different. Typically, the allelic variants carrying Val in codon nine showed higher protein synthesis (P < 0.05), and the allelic variants carrying neutral Gln in codon 22 and Gly in codon 25 showed higher secretion proportion (P < 0.05) compared with the other groups as assessed by western blotting. In silico RNA folding prediction indicated that the mutations gave rise to different RNA secondary structures, suggesting that they might affect translation and protein synthesis. CONCLUSION: We conclude that the missense mutations within the signal sequence influence the expression and the secretion of the protein. To the best of our knowledge, this is the first report addressing the functional consequences of the mutations in the signal peptide of porcine GH gene.
Entities:
Keywords:
Cellular secretion; GH gene; RNA fold; Signal peptide