Analysis of the pH requirement for membrane fusion of different isolates of the paramyxovirus parainfluenza virus 5.
Paramyxoviruses enter cells by fusing their envelopes with the plasma membrane, a process that occurs at neutral pH. Recently, it has been found that there is an exception to this dogma in that a porcine isolate of the paramyxovirus parainfluenza virus 5 (PIV5), known as SER, requires a low-pH step for fusion (S. Seth, A. Vincent, and R. W. Compans, J. Virol. 77: 6520-6527, 2003). As a low-pH activation mechanism for fusion would greatly facilitate biophysical studies of paramyxovirus-mediated membrane fusion, we have reexamined the triggering of the PIV5 SER fusion protein. Using multiple assays, we could not find a requirement for low-pH triggering of PIV5 SER fusion. The challenge of discovering how the paramyxovirus receptor binding protein (HN, H, or G) activates the metastable fusion protein to cause membrane fusion at neutral pH remains.
Bissonnette
Mei Lin Z
ML
Department of Biochemistry, Molecular Biology, and Cell Biology, Northwestern University, 2205 Tech Drive, Evanston, Illinois 60208-3500, USA.
Connolly
Sarah A
SA
Young
Daniel F
DF
Randall
Richard E
RE
Paterson
Reay G
RG
Lamb
Robert A
RA
D000818:Animals; D002459:Cell Fusion; D002460:Cell Line; D004910:Erythrocyte Membrane / Q000821:virology; D015726:Giant Cells / Q000502:physiology; D006863:Hydrogen-Ion Concentration; D008561:Membrane Fusion / Q000502:physiology*; D018098:Paramyxovirinae / Q000302:isolation & purification / Q000472:pathogenicity* / Q000502:physiology; D013552:Swine / Q000821:virology; D014760:Viral Fusion Proteins / Q000378:metabolism; D010948:Viral Plaque Assay; D014764:Viral Proteins / Q000378:metabolism; D014779:Virus Replication
D014760:Viral Fusion Proteins; D014764:Viral Proteins