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Vous êtes ici : Accueil / Équipes / Régulation Post-transcriptionnelle dans l'Infection et l'Oncogenèse - Jalinot/Mocquet / Thèmes de recherche / Effects of DHX36 on RNA G4 quadruplexes (Stéphane Réty- projet 2)

Effects of DHX36 on RNA G4 quadruplexes (Stéphane Réty- projet 2)

G-quadruplexes (G4s) are four-stranded secondary structures held together by layers of four Guanines (G) interacting by non-canonical G-G base pairs. Once formed, G4s are highly stable and can act as barriers blocking replication, transcription and translation.

G-quadruplexes (G4s) are four-stranded secondary structures held together by layers of four Guanines (G) interacting by non-canonical G-G base pairs. Once formed, G4s are highly stable and can act as barriers blocking replication, transcription and translation. In contrast to DNA G4s, RNA G4s (rG4s) importance has been controversial. 13000 RNA Potential G-Quadruplex forming Sequences (PQS) have been identified by bioinformatics in the transcriptome but very few are folded as rG4 in cellular context, though they are predicted to be more stable than DNA G4s. Several helicases have been identified to resolve rG4s as the DEAD-box helicases DDX5, DDX17, DDX21 and MOV10L1 but the major activity is held by specific RNA helicases from the DEAH family DHX9 (also named RHA) and DHX36 (also named RHAU or G4R1). DHX36 is responsible for the major rG4 resolving activity in HeLa cells. and is of particular importance for regulation of translation initiation by resolving specific rG4 in the 5' UTR. Though rG4s in the 5' UTR have carried out much attention, less is known about rG4s in the 3' UTR of mRNA. rG4 in the 3'-UTR have been involved in translation initiation inhibition, increase of alternative polyadenylation site and miRNA binding inhibition, showing that these rG4s are potential cis-regulating element of mRNA. 

Our project here is to assess the importance of rG4 for mRNA stability.