Last data update: Apr 29, 2024. (Total: 46658 publications since 2009)
Records 1-3 (of 3 Records) |
Query Trace: Moss KJ[original query] |
---|
Amino acid changes within the E protein hinge region that affect dengue virus type 2 infectivity and fusion
Butrapet S , Childers T , Moss KJ , Erb SM , Luy BE , Calvert AE , Blair CD , Roehrig JT , Huang CY . Virology 2011 413 (1) 118-27 Fifteen mutant dengue viruses were engineered and used to identify AAs in the molecular hinge of the envelope protein that are critical to viral infection. Substitutions at Q52, A54, or E133 reduced infectivity in mammalian cells and altered the pH threshold of fusion. Mutations at F193, G266, I270, or G281 affected viral replication in mammalian and mosquito cells, but only I270W had reduced fusion activity. T280Y affected the pH threshold for fusion and reduced replication in C6/36 cells. Three different mutations at L135 were lethal in mammalian cells. Among them, L135G abrogated fusion and reduced replication in C6/36 cells, but only slightly reduced the mosquito infection rate. Conversely, L135W replicated well in C6/36 cells, but had the lowest mosquito infection rate. Possible interactions between hinge residues 52 and 277, or among 53, 135, 170, 186, 265, and 276 required for hinge function were discovered by sequence analysis to identify compensatory mutations. |
Domain-III FG loop of the dengue virus type 2 envelope protein is important for infection of mammalian cells and Aedes aegypti mosquitoes
Erb SM , Butrapet S , Moss KJ , Luy BE , Childers T , Calvert AE , Silengo SJ , Roehrig JT , Huang CY , Blair CD . Virology 2010 406 (2) 328-35 The FG extended loop in domain III of the dengue virus type 2 (DENV2) envelope protein is postulated to be a molecular determinant for host cell infectivity. To determine the contribution of the FG loop to virus infectivity, an infectious cDNA clone of DENV2 was manipulated by deleting amino acids in the loop (VEPGDelta) to mimic tick-borne flaviviruses or by substituting these AAs with RGD or RGDK/S to mimic motifs present in other mosquito-borne flaviviruses. We found the FG loop to be dispensable for infection of C6/36 cells but critical for infection of Aedes aegypti mosquito midguts and mammalian cells. All the FG loop mutants were able to bind to and enter mammalian cells but replication of VEPGDelta in Vero cells at 37 degrees C was delayed until acquisition of secondary mutations. Reduced binding of DENV2 type-specific monoclonal antibody 3H5 to mutant viruses confirmed the FG loop motif as its target epitope. |
The dengue virus type 2 envelope protein fusion peptide is essential for membrane fusion
Huang CY , Butrapet S , Moss KJ , Childers T , Erb SM , Calvert AE , Silengo SJ , Kinney RM , Blair CD , Roehrig JT . Virology 2009 396 (2) 305-15 The flaviviral envelope (E) protein directs virus-mediated membrane fusion. To investigate membrane fusion as a requirement for virus growth, we introduced 27 unique mutations into the fusion peptide of an infectious cDNA clone of dengue 2 virus and recovered seven stable mutant viruses. The fusion efficiency of the mutants was impaired, demonstrating for the first time the requirement for specific FP AAs in optimal fusion. Mutant viruses exhibited different growth kinetics and/or genetic stabilities in different cell types and adult mosquitoes. Virus particles could be recovered following RNA transfection of cells with four lethal mutants; however, recovered viruses could not re-infect cells. These viruses could enter cells, but internalized virus appeared to be retained in endosomal compartments of infected cells, thus suggesting a fusion blockade. Mutations of the FP also resulted in reduced virus reactivity with flavivirus group-reactive antibodies, confirming earlier reports using virus-like particles. |
- Page last reviewed:Feb 1, 2024
- Page last updated:Apr 29, 2024
- Content source:
- Powered by CDC PHGKB Infrastructure