Dengue virus PrM/M proteins fail to show pH-dependent ion channel activity in Xenopus oocytes.
The transmembrane domains (TMDs) of dengue virus type-1 M protein (DENV-1M) were reported to form cation-selective channels in artificial lipid bilayers. We further explored this observation using the two-electrode voltage clamp (TEVC) method on the Xenopus laevis oocytes expressing DENV PrM and M proteins. Using myc epitope tagged M proteins, M was first shown to adopt its predicted native topology in mammalian cells when expressed on its own. The recombinant proteins were then successfully expressed on the surface of Xenopus oocytes. Using influenza A M2 (Inf A/M2) protein as a control, we measured the conductance of oocytes expressing DENV proteins under hyperpolarized or low-pH conditions. Inf A/M2 showed pH-dependent, amantadine-sensitive channel activity that was consistent with previously published reports. However, no activity was detected for DENV proteins. We conclude that DENV PrM and M proteins do not show pH-activated ion channel activity.
Burnet Institute, 85 Commercial Road, Melbourne, Vic. 3004, Australia.
Sook-San
SS
Wong
Mary
M
Chebib
Gholamreza
G
Haqshenas
Bruce
B
Loveland
Eric J
EJ
Gowans
D000818:Animals; D003716:Dengue Virus / Q000472:pathogenicity*; D005260:Female; D006863:Hydrogen-Ion Concentration; D007473:Ion Channels / Q000378:metabolism*; D009865:Oocytes / Q000821:virology*; D018408:Patch-Clamp Techniques / Q000379:methods; D014764:Viral Proteins / Q000378:metabolism*; D014982:Xenopus laevis / Q000821:virology*
D007473:Ion Channels; D014764:Viral Proteins