The Effects of an Amino Acid Substitution in the Envelope Protein of Japanese Encephalitis Virus on PI3K/Akt Signal Transdution and Virus Replication

• Main Authors: CHEN, KE-WEI, 陳科維
• Other Authors: CHEN, SHIH-SHUN
• Format: Others
• Language: zh-TW
• Published: 2016
• Online Access: http://ndltd.ncl.edu.tw/handle/2x2rvh

碩士 === 中臺科技大學 === 醫學檢驗生物技術系碩士班 === 104 === The envelope (E) protein of Japanese encephalitis virus (JEV) plays a central role in receptor binding specificity and in determining the early stages of virus infection. The E protein can induce a phosphatidylinositol 3–kinase (PI3K)/protein kinase B (Akt)-dependent survival signal to protect virus-infected cells from early apoptotic cell death. The effect of specific amino acids in the E protein on PI3K/Akt pathway related to cell survival and early viral replication was not determined. We found that JEV E protein mutant strains E138A, S275P, R387E, D389G, K398Q and R416T, enhanced phosphorylation of Akt and inhibited apoptosis in the early stages. Real-time PCR analysis of viral RNAs showed that mutant viruses S275P, R387E, D389G, D389H, and K398Q exhibited increased synthesis of negative-strand RNA as early as one hour postinfection. Interestingly, mutants D389G and K398Q did not increase the expression levels of Bax in one and six hours postinfection. These results suggest the involvement of residues D389 and K398 of the E protein in modulating PI3K/Akt-dependent survival signaling and early steps of viral RNA replication.