Project description:RNA quality control pathways serve to get rid of faulty RNAs and therefore must be able to discriminate these RNAs from those that are normal. Here we present evidence that the ATPase cycle of SF1 Helicase Upf1 is required for mRNA discrimination during Nonsense-Mediated Decay (NMD). Mutations affecting the Upf1 ATPase cycle disrupt the mRNA selectivity of Upf1, leading to indiscriminate accumulation of NMD complexes on both NMD target and non-target mRNAs. In addition, two modulators of NMD - translation and termination codon-proximal poly(A) binding protein - depend on Upf1 ATPase to limit Upf1-non-target association. Preferential ATPase-dependent dissociation of Upf1 from non-target mRNAs in vitro suggests that selective release of Upf1 contributes to the ATPase-dependence of Upf1 target discrimination. Given the prevalence of helicases in RNA regulation, ATP hydrolysis may be an underappreciated, yet widely employed, activity in target RNA discrimination. CLIP and RIP-seq against Wild Type and Mutant Upf1 in HEK293-T cell lines
Project description:RNA quality control pathways serve to get rid of faulty RNAs and therefore must be able to discriminate these RNAs from those that are normal. Here we present evidence that the ATPase cycle of SF1 Helicase Upf1 is required for mRNA discrimination during Nonsense-Mediated Decay (NMD). Mutations affecting the Upf1 ATPase cycle disrupt the mRNA selectivity of Upf1, leading to indiscriminate accumulation of NMD complexes on both NMD target and non-target mRNAs. In addition, two modulators of NMD - translation and termination codon-proximal poly(A) binding protein - depend on Upf1 ATPase to limit Upf1-non-target association. Preferential ATPase-dependent dissociation of Upf1 from non-target mRNAs in vitro suggests that selective release of Upf1 contributes to the ATPase-dependence of Upf1 target discrimination. Given the prevalence of helicases in RNA regulation, ATP hydrolysis may be an underappreciated, yet widely employed, activity in target RNA discrimination. CLIP and RIP-seq against Wild Type and Mutant Upf1 in HEK293-T cell lines
Project description:RNA quality control pathways serve to get rid of faulty RNAs and therefore must be able to discriminate these RNAs from those that are normal. Here we present evidence that the ATPase cycle of SF1 Helicase Upf1 is required for mRNA discrimination during Nonsense-Mediated Decay (NMD). Mutations affecting the Upf1 ATPase cycle disrupt the mRNA selectivity of Upf1, leading to indiscriminate accumulation of NMD complexes on both NMD target and non-target mRNAs. In addition, two modulators of NMD - translation and termination codon-proximal poly(A) binding protein - depend on Upf1 ATPase to limit Upf1-non-target association. Preferential ATPase-dependent dissociation of Upf1 from non-target mRNAs in vitro suggests that selective release of Upf1 contributes to the ATPase-dependence of Upf1 target discrimination. Given the prevalence of helicases in RNA regulation, ATP hydrolysis may be an underappreciated, yet widely employed, activity in target RNA discrimination.
Project description:RNA quality control pathways serve to get rid of faulty RNAs and therefore must be able to discriminate these RNAs from those that are normal. Here we present evidence that the ATPase cycle of SF1 Helicase Upf1 is required for mRNA discrimination during Nonsense-Mediated Decay (NMD). Mutations affecting the Upf1 ATPase cycle disrupt the mRNA selectivity of Upf1, leading to indiscriminate accumulation of NMD complexes on both NMD target and non-target mRNAs. In addition, two modulators of NMD - translation and termination codon-proximal poly(A) binding protein - depend on Upf1 ATPase to limit Upf1-non-target association. Preferential ATPase-dependent dissociation of Upf1 from non-target mRNAs in vitro suggests that selective release of Upf1 contributes to the ATPase-dependence of Upf1 target discrimination. Given the prevalence of helicases in RNA regulation, ATP hydrolysis may be an underappreciated, yet widely employed, activity in target RNA discrimination.
Project description:RNA helicases are important regulators of gene expression that act by remodeling RNA secondary structures and as RNA-protein interactions. Here, we demonstrate that MOV10 has an ATP-dependent 5' to 3' in vitro RNA unwinding activity and determine the RNA-binding sites of MOV10 and its helicase mutants using PAR-CLIP. We find that MOV10 predominantly binds to 3' UTRs upstream of regions predicted to form local secondary structures and provide evidence that MOV10 helicase mutants are impaired in their ability to translocate 5' to 3' on their mRNA targets. MOV10 interacts with UPF1, the key component of the nonsense-mediated mRNA decay pathway. PAR-CLIP of UPF1 reveals that MOV10 and UPF1 bind to RNA in close proximity. Knockdown of MOV10 resulted in increased mRNA half-lives of MOV10-bound as well as UPF1-regulated transcripts, suggesting that MOV10 functions in UPF1-mediated mRNA degradation as an RNA clearance factor to resolve structures and displace proteins from 3' UTRs. Flp-In T-REx HEK293 cells expressing FLAG/HA-tagged MOV10 WT, MOV10 K530A, MOV10 D645N and UPF1 were sequenced. mRNA half-life data under GSE56751.
Project description:A majority of metazoan mRNAs are under microRNA (miRNA)/Argonaute (Ago)-mediated control of RNA stability at the post-transcriptional level. Although the molecular mechanism of the miRNA-mediated repression of target mRNAs through Ago/TNRC6 pathway have been largely elucidated, however, the existence of alternative TNRC6-independent miRNA-mediated post-transcriptional gene regulation pathway remains unknown. Here, we suggest that endogenous miRNAs (endo-miRNAs) can downregulate the target mRNAs via the alternative molecular pathway, Ago-associated UPF1/SMG7, core mediators of nonsense-mediated mRNA decay. Global analyses of mRNAs in a response to UPF1 RNA interference in miRNA-deficient cells reveal that 3’UTR-length-dependent mRNA decay by UPF1 requires endo-miRNA targeting via CUG motif. The repression of miRNA targets is more additively or synergistically accomplished by combination of Ago2 and UPF1 through UPF1-associated SMG7, recruiting CCR4-NOT deadenylase complex, in TNRC6-independent manner. We expect that the new miRNA-mediated mRNA decay pathway enables the miRNA targeting to become more predictable and expand the miRNA-mRNA regulatory network.
Project description:RNA helicases are important regulators of gene expression that act by remodeling RNA secondary structures and as RNA-protein interactions. Here, we demonstrate that MOV10 has an ATP-dependent 5' to 3' in vitro RNA unwinding activity and determine the RNA-binding sites of MOV10 and its helicase mutants using PAR-CLIP. We find that MOV10 predominantly binds to 3' UTRs upstream of regions predicted to form local secondary structures and provide evidence that MOV10 helicase mutants are impaired in their ability to translocate 5' to 3' on their mRNA targets. MOV10 interacts with UPF1, the key component of the nonsense-mediated mRNA decay pathway. PAR-CLIP of UPF1 reveals that MOV10 and UPF1 bind to RNA in close proximity. Knockdown of MOV10 resulted in increased mRNA half-lives of MOV10-bound as well as UPF1-regulated transcripts, suggesting that MOV10 functions in UPF1-mediated mRNA degradation as an RNA clearance factor to resolve structures and displace proteins from 3' UTRs. Flp-In T-REx HEK293 cells expressing FLAG/HA-tagged MOV10 WT, MOV10 K530A, MOV10 D645N and UPF1 were used to determine the protein-RNA interaction sites of RNA helicases MOV10 and UPF1 as well as MOV10 inactive variants using PAR-CLIP in combination with next generation sequencing. mRNA half-life changes of MOV10-targeted mRNA were determined by measuring mRNA half-lives by mRNA sequencing of mock and MOV10-depleted HEK293 cells.
Project description:RNA helicases are important regulators of gene expression that act by remodeling RNA secondary structures and as RNA-protein interactions. Here, we demonstrate that MOV10 has an ATP-dependent 5' to 3' in vitro RNA unwinding activity and determine the RNA-binding sites of MOV10 and its helicase mutants using PAR-CLIP. We find that MOV10 predominantly binds to 3' UTRs upstream of regions predicted to form local secondary structures and provide evidence that MOV10 helicase mutants are impaired in their ability to translocate 5' to 3' on their mRNA targets. MOV10 interacts with UPF1, the key component of the nonsense-mediated mRNA decay pathway. PAR-CLIP of UPF1 reveals that MOV10 and UPF1 bind to RNA in close proximity. Knockdown of MOV10 resulted in increased mRNA half-lives of MOV10-bound as well as UPF1-regulated transcripts, suggesting that MOV10 functions in UPF1-mediated mRNA degradation as an RNA clearance factor to resolve structures and displace proteins from 3' UTRs.