The great nuclear escape: the mechanism of membrane deformation during non-canonical nuclear export in herpesviruses

Katya Heldwein, Tufts University School of Medicine
Herpesviruses are large viruses that infect nearly all vertebrates and some invertebrates and cause lifelong infections in most of the world’s population. During replication, they export their capsids from the nucleus into the cytoplasm by an unusual mechanism termed nuclear egress. Too large to fit through nuclear pores, capsids instead bud at the inner nuclear membrane forming enveloped capsid particles in the perinuclear space. These particles then fuse with the outer nuclear membrane releasing the capsids into the cytoplasm where they mature into infectious virions. The seminar will focus on the nuclear budding step. This process is mediated by the virus-encoded heterodimeric complex termed the nuclear egress complex (NEC). This presentation will describe how the NEC uses lipid ordering and protein oligomerization to deform membranes and cause budding. Similar principles may underlie membrane deformation in other systems.