Ultrastructural organization of recombinant Marburg virus nucleoprotein: Comparison with Marburg virus inclusions

HeLa cells expressing the recombinant Marburg virus (MBGV) nucleoprotein (N P) have been studied by immunoelectron microscopy. It was found that MBGV N Ps assembled into large aggregates which were in close association with mem branes of the rough endoplasmic reticulum. Further analysis of these aggreg ates revealed that NPs formed tubule-like structures which were arranged in a hexagonal pattern, A similar pattern of preformed nucleocapsids was dete cted in intracellular inclusions induced by MBGV infection. Our data indica ted that MBGV NP is able to form nucleocapsid-like structures in the absenc e of the authentic viral genome and other nucleocapsid-associated proteins.