Study of Junín arenavirus glycoproteins association to cholesterol enriched membrane domains

MARTINEZ, GUADALUPE; CORDO, SANDRA Y CANDURRA, NÉLIDA.

Mar del Plata, Buenos Aires, Argentina

Congreso; XLIII Reunión Anual de la Sociedad Argentina de Investigación en Bioquímica y Biología Molecular; 2007

SAIB (lSociedad Argentina de Investigación en Bioquímica y Biología Molecular)

Arenavirus morphogenesis and budding occurs at cellular plasma membrane; however, the nature of membrane assembly sites remains poorly understood. In this study we examined the effect of several cholesterol-lowering agents on Junín virus (JUNV) multiplication in Vero cells. We found that cholesterol cell depletion reduced JUNV infectivity and glycoproteins (GPs) localization on the cell surface, while nucleoprotein (NP) and GPs expression remains constant inside. Analysis of NP presence in supernatant of cholesterol depleted cells suggests that a reduced amount of virions are budding from infected cells, instead of non infective ones. Treatment with triton X-100 followed for gradient fractionation demonstrated that JUNV GPs associate with cholesterol enriched membranes microdomains. Membrane raft localization of JUNV GPs was impaired at warm detergent extraction or when cholesterol was removed by methyl-b-cyclodextrin compound. Specific cross-linking studies with anti-GP antibodies demonstrated to improve detergent insolubility at 37ºC by rafts stabilization. On the other hand our findings showed that NP was differentially localized in soluble fractions. These results demonstrate the association of JUNV GPs to cholesterol enriched membranes and suggest a role of rafts microdomains in the process of viral assembly and budding.