The dengue virus type 2 envelope protein fusion peptide is essential for membrane fusion.
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.
Huang
Claire Y-H
CY
Division of Vector-Borne Infectious Diseases, Centers for Disease Control and Prevention, Public Health Service, U.S. Department of Health and Human Services, 3150 Rampart Rd., Fort Collins, CO 80521, USA. CHuang1@cdc.gov
Butrapet
Siritorn
S
Moss
Kelly J
KJ
Childers
Thomas
T
Erb
Steven M
SM
Calvert
Amanda E
AE
Silengo
Shawn J
SJ
Kinney
Richard M
RM
Blair
Carol D
CD
Roehrig
John T
JT
D000330:Aedes / Q000821:virology; D000818:Animals; D000956:Antigens, Viral / Q000276:immunology; D002460:Cell Line; D002522:Chlorocebus aethiops; D003715:Dengue / Q000821:virology; D003716:Dengue Virus / Q000235:genetics / Q000502:physiology*; D005260:Female; D008561:Membrane Fusion / Q000502:physiology*; D016297:Mutagenesis, Site-Directed; D014162:Transfection; D014709:Vero Cells; D014760:Viral Fusion Proteins / Q000235:genetics / Q000502:physiology*; D014779:Virus Replication / Q000235:genetics / Q000502:physiology
D000956:Antigens, Viral; D014760:Viral Fusion Proteins