Understanding Triatoma Virus (TrV) Disassembly and Genome Release

SANCHEZ- EUGENIA, R; AGUIRRE, J; SNIJDER, J; UETRECHT, C; NEUMANN, E; MARTI G. A; GUERIN, D.M.A.; HECK, A; GIJS, J.L; WUITE, G; ROOS, W

Workshop; II International Workshop on Chagas Disease, triatomine vectors, Trypanosoma cruzi, and Triatoma virus.; 2012

TrV is a spherical, non-enveloped, +ssRNA virus that infects the triatomine T. infestans (Hemiptera: Reduviidae) and belongs to the Dicistroviridae family. In the present work we study how viral RNA promotes pH-dependent disassembly into pentamers. These studies have been carried out using Dynamic Light Scattering, Atomic Force Microscopy Nanoindentation, Transmission Electron Microscopy, Cryo-electron microscopy reconstructions and native-PAGE. We also set up a rationale for these experimental data carrying out electrostatic calculations between viral capsid subunits in aqueous solution. These calculations have been performed using the Adaptative Poisson- Boltzman Solver (APBS) software. Given all these experimental and theoretical data we postulate that at neutral pH, the virion protein shell is stabilized by the densely packed single stranded RNA. However, under increasingly alkaline conditions, the RNA starts to destabilize the capsid triggering its disassembly into pentameric subunits and subsequent genome release. Acknowledgments This work was financially supported by FBB (Fundación Biofisica Bizkaia), FOM (Fundamenteel Onderzoek der Materie) through the ?Physics of the genome? programme (to GJLW), by the CYTED programme, by the Netherlands Proteomics Centre and by the Netherlands Organisation for Scientific Research (NWO); ALW-ECHO (819.02.10) to AJRH. R.S.E. acknowledges a predoctoral grant from the Basque Government. JA was supported by a UPV/EHU contract (UPV-IT-461-07).D.M.A.G. was partially supported by Bizkaia:Xede association, UPV/EHU (IT-461-07), CYTED (209RT0364), and MICINN (BFU2007-62062), Spain.