Remodeling of host membranes during herpesvirus assembly and egress

Abstract

Many viruses, enveloped or non-enveloped, remodel host membrane structures for their replication, assembly and escape from host cells. Herpesviruses are important human pathogens and cause many diseases. As large enveloped DNA viruses, herpesviruses undergo several complex steps to complete their life cycles and produce infectious progenies. Firstly, herpesvirus assembly initiates in the nucleus, producing nucleocapsids that are too large to cross through the nuclear pores. Nascent nucleocapsids instead bud at the inner nuclear membrane to form primary enveloped virions in the perinuclear space followed by fusion of the primary envelopes with the outer nuclear membrane, to translocate the nucleocapsids into the cytoplasm. Secondly, nucleocapsids obtain a series of tegument proteins in the cytoplasm and bud into vesicles derived from host organelles to acquire viral envelopes. The vesicles are then transported to and fuse with the plasma membrane to release the mature virions to the extracellular space. Therefore, at least two budding and fusion events take place at cellular membrane structures during herpesviruses assembly and egress, which induce membrane deformations. In this review, we describe and discuss how herpesviruses exploit and remodel host membrane structures to assemble and escape from the host cell.

HSV Forms an HCMV-like Viral Assembly Center in Neuronal Cells

“…The organization of host membranes. The identity of the membrane at which HSV 449 cytoplasmic envelopment occurs in epithelial cells is currently controversial, with evidence 450 supporting both trans Golgi and endosomal membranes, but not ER (Lv et al, 2019). The 451 arrangement of host Golgi, ER, and some endosomal membranes in the HSV neuronal cVAC is 452 broadly consistent with previous results derived from epithelial cell studies.…”

Duck plague virus gE serves essential functions during the virion final envelopment through influence capsids budding into the cytoplasmic vesicles

“…Deleting PRV gE cytoplasmic tail and gM inhibited nucleocapsids to bind onto TGN 25 . The molecular basis for final envelopment was implicated in the interactions of capsid proteins, tegument proteins and glycoproteins 28 . Tegument proteins served as a bridge to interact with capsids on one side and the glycoproteins Table 1.…”

“…At present, the molecular basis of virus budding into the TGN membrane to acquire the final envelopment was unclear at exactly. Some papers speculated that the cytoplasmic tails of glycoproteins may make contact with tegument proteins for driving the final budding process, but others believed that the stability protein networks constructed by glycoproteins and tegument proteins on the surface of TGN membrane may allow the budding process to occur 20,28,31 .…”

Mass Spectrometric Characterization of HSV-1 L-Particles From Human Dendritic Cells and BHK21 Cells and Analysis of Their Functional Role

“…Having passed the nuclear membrane, capsids get coated with tegument proteins by a step called tegumentation (Vittone et al, 2005;Henaff et al, 2013). In a last step, virions bud of cytoplasmic membranes, such as derived from the trans-Golgi network or endosomes, providing the lipid envelope of mature virions (secondary envelopment) for the subsequent release (Lv et al, 2019). Apart from mature infectious virions, so-called heavy (H-) particles, a lytic HSV-1 infection will also give rise to the production of light (L-) particles, which are void of the capsid and thus are not infectious (Hogue et al, 2016).…”