Eukaryotic-Like Virus Budding in Archaea - Institut Pasteur Access content directly
Journal Articles mBio Year : 2016

Eukaryotic-Like Virus Budding in Archaea


Similar to many eukaryotic viruses (and unlike bacteriophages), viruses infecting archaea are often encased in lipid-containing envelopes. However, the mechanisms of their morphogenesis and egress remain unexplored. Here, we used dual-axis electron tomography (ET) to characterize the morphogenesis of Sulfolobus spindle-shaped virus 1 (SSV1), the prototype of the family Fuselloviridae and representative of the most abundant archaea-specific group of viruses. Our results show that SSV1 assembly and egress are concomitant and occur at the cellular cytoplasmic membrane via a process highly reminiscent of the budding of enveloped viruses that infect eukaryotes. The viral nucleoprotein complexes are extruded in the form of previously unknown rod-shaped intermediate structures which have an envelope continuous with the host membrane. Further maturation into characteristic spindle-shaped virions takes place while virions remain attached to the cell surface. Our data also revealed the formation of constricted ring-like structures which resemble the budding necks observed prior to the ESCRT machinery-mediated membrane scission during egress of various enveloped viruses of eukaryotes. Collectively, we provide evidence that archaeal spindle-shaped viruses contain a lipid envelope acquired upon budding of the viral nucleoprotein complex through the host cytoplasmic membrane. The proposed model bears a clear resemblance to the egress strategy employed by enveloped eu-karyotic viruses and raises important questions as to how the archaeal single-layered membrane composed of tetraether lipids can undergo scission. IMPORTANCE The replication of enveloped viruses has been extensively studied in eukaryotes but has remained unexplored for enveloped viruses infecting bacteria and archaea. Here, we provide a sequential view on the assembly and egress of SSV1, a pro-totypic archaeal virus. The observed process is highly similar to the budding of eukaryotic enveloped viruses, including human immunodeficiency virus, influenza virus, and Ebola virus. The present study is the first to characterize such a phenomenon in archaeal cells, showing that membrane budding is not an exclusive feature of eukaryotic viruses. Our results provide significant insights into the biogenesis and architecture of unique, spindle-shaped virions that infect archaea. Furthermore, our findings open doors for future inquiries into (i) the evolution of the virus budding process, (ii) mechanistic details of virus-mediated membrane scission in Archaea, and (iii) elucidation of virus-and host-encoded molecular players responsible for archaeal membrane and surface remodeling.


Fichier principal
Vignette du fichier
mBio-2016-Quemin-.pdf (1.25 Mo) Télécharger le fichier
Origin Publication funded by an institution

Dates and versions

pasteur-01375476 , version 1 (03-10-2016)




Emmanuelle R J Quemin, Petr Chlanda, Mart Sachse, Patrick Forterre, David Prangishvili, et al.. Eukaryotic-Like Virus Budding in Archaea. mBio, 2016, 7, pp.1439 - 1455. ⟨10.1128/mBio.01439-16⟩. ⟨pasteur-01375476⟩
214 View
140 Download



Gmail Mastodon Facebook X LinkedIn More