Molecular Virology

Group leader

Since their discovery, viruses have constantly attracted attention, firstly because they are infectious agents, but also because they can be used as small-scale models for the study of more complex cells. Viruses compensate for the limited amount of information in their small genome by using a number of sophisticated strategies that enable them to multipy by diverting cellular components for their own benefit.

Many important animal, plant, bacterial and fungal viruses have genomes of positive-stranded RNA. It has become increasingly clear, from the sequencing of these genomes, that, at the molecular level, the viruses have many features in common. Such broad sequence conservation among positive strand RNA viruses therefore suggests that they use similar replication strategies and mechanisms.

The aim of our group is to elucidate the molecular basis of viral replication. We are currently studying TYMV (turnip yellow mosaic virus), a plant virus that is extremely well characterized at the molecular level and is one of the few viruses able to infect the model plant Arabidopsis thaliana.

The replication of the viral RNA genome is an intricate process that involves a replication complex formed of not only partners of both viral and cellular origin, but also the viral RNA template. Replication complexes are embedded within particular virus-induced membrane vesicles. The replication process is particularly efficient since a single infected cell is capable of producing millions of viral particles within a few hours.

Using a combination of molecular, cellular, biochemical and genetic approaches, we are currently studying the molecular mechanisms controlling the assembly, membrane targetting and regulation of TYMV replication complexes. We are particularly interested in the viral RNA-dependent RNA polymerase (RdRp), a protein that is essential for the replication cycle. Our projects aim at&nbs

  • understanding the molecular mechanisms that regulate RdRp function
  • identifying how viral replication complexes are targetted to viral-induced cellular membrane structures
  • studying the assembly of the viral replication complexes
  • identifying the cellular proteins participating in viral replication.

This should give us a better understanding of the molecular basis of viral replication, a prerequisite for the development of new antiviral strategies.

photo jupin web 2005 14034

 TYMV replication complexes are localized at the periphery of chloroplasts within an infected cell. The viral RNA-dependent RNA polymerase is detected by indirect immunofluorescence (green), while chloroplastic and nuclear DNA are visualized by DAPI counterstaining (blue).
Copyright CNRS/IJM Prod'homme

Selection of publications

A viral deubiquitylating enzyme targets viral RNA-dependent RNA polymerase
and affects viral infectivity.
Chenon M, Camborde L, Cheminant S, Jupin I.
EMBO J. (2012), 31,741-753.
Abstract

The ubiquitin-proteasome system regulates the accumulation of Turnip
yellow mosaic virus
RNA-dependent RNA polymerase during viral infection.
Camborde L, Planchais S, Tournier V, Jakubiec A, Drugeon G, Lacassagne E,
Pflieger S, Chenon M, Jupin I.
Plant Cell. 2010 Sep;22(9):3142-52.
Abstract & full text

Efficient virus-induced gene silencing in Arabidopsis using a 'one-step'
TYMV-derived vector.
Pflieger S, Blanchet S, Camborde L, Drugeon G, Rousseau A, Noizet M,
Planchais S, Jupin I.
Plant J. 2008 Nov;56(4):678-90.
Abstract & full text

Proteolytic processing of turnip yellow mosaic virus replication proteins
and functional impact on infectivity.
Jakubiec A, Drugeon G, Camborde L, Jupin I.
J Virol. 2007 Oct;81(20):11402-12.
Abstract & full text

Phosphorylation of viral RNA-dependent RNA polymerase and its role in
replication of a plus-strand RNA virus.
Jakubiec A, Tournier V, Drugeon G, Pflieger S, Camborde L, Vinh J,
Héricourt F, Redeker V, Jupin I.
J Biol Chem. 2006 Jul 28;281(30):21236-49.
Abstract & full text

Last modified 31 August 2017

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