The Endosomes and the Golgi complex are involved in the Infectious Bursal Disease Virus life cycle

DELGUI, L.R.; RODRÍGUEZ, J.F; COLOMBO, M.I.

Mendoza

Congreso; XLVII Reunión Anual de la Sociedad Argentina de Investigaciones en Bioquímica y Biología Molecular; 2012

Infectious bursal disease virus (IBDV) is a dsRNA virus that causes severe disease in chickens. We have defined the cellular localization of replication complexes of IBDV based on colocalization analysis of two main viral components, the proteins VP3 and VP1. Our results indicate that VP3 and VP1 localized to vesicular structures with features of early and late/lysosomal endocytic compartments located in the juxtanuclear region of infected cells. Employing well-established Golgi complex markers we found that VP3-containing vesicles were closely associated to the Golgi apparatus. Depolymerizing the microtubule network with nocodazole, which reorganizes the Golgi complex into mini-stacks, and Brefeldin A-treatment, that causes the dispersion of the Golgi complex, caused a profound change in the VP3 localization depicting a punctate distribution scattered throughout the cytoplasm, remaining strongly associated to the Golgi mini-stacks. Analysis of intracellular viral protein levels and viral infective particles in BfA-treated infected cells indicates that these parameters were markedly affected, suggesting a role for the Golgi complex in the replication of IBDV. These results constitute the first study toward elucidating the subcellular localization of IBDV replication complexes and in establishing a link between the endo/lysosomal and the secretory pathways with the process.