The seminars take place on the Montpellier Institut Agro/INRAE Campus of La Gaillarde (2, place P. Viala Montpellier)

Thursday  may 21 2026 à 14h, Amphi 208

Christophe Ritzenthaler
IBMP (Institut de biologie moléculaire des plantes), Strasbourg

RNA viruses establish membrane-bound replication factories in host cells, generating double-stranded RNA (dsRNA) intermediates that act as danger signals triggering both sequence-specific and broad-spectrum antiviral defenses.In plants, dsRNA is primarily detected by the RNA interference (RNAi) pathway. Dicer enzymes process long dsRNA into small interfering RNAs (siRNAs), which guide the RNA-induced silencing complex (RISC) to degrade complementary viral RNA. In virus-infected Arabidopsis and N. benthamiana plants, we identified a novel dsRNA-binding protein of unknown function. Through extensive biochemical investigations, we determined its binding affinity for dsRNA and resolved its high-resolution structure in complex with dsRNA, revealing critical residues involved in binding. We further characterized the protein’s subcellular localization in healthy and virus-infected plants, identifying residues responsible for its compartment targeting. CRISPR/Cas9-generated Arabidopsis knockout lines are currently being used to investigate the protein’s interplay with the RNAi machinery. Beyond its biological significance, this protein holds biotechnological potential for improving dsRNA detection and viral surveillance.

Contact : Alexandre Martinière