Project description:Here, we report the genome-wide analysis of snRNAs that are bound to Gemin5 upon protein synthesis inhibition. Upon protein synthesis inhibition, the SMN complex that has a crucial role in the biogenesis of snRNPs dissociates into its subunits, leaving Gemin5 alone. The existence of these subunits was confirmed using a proteomics approach. As Gemin5 has been previously reported to be the RNA-binding protein of the SMN complex, we obtained the sequence of all Gemin5 immunoprecipitated snRNAs. We found that snRNAs that were accumulated on Gemin5 contained extra genomic sequences at the 3'-end. We were thus able to identify novel precursors of all the snRNAs that have not been identified previously. This study also provides a detailed method for the characterization of in vivo captured RNPs using a ribo-proteomics approach. Investigation of snRNAs specifically associated with Gemin5 upon protein synthesis inhibition
Project description:Here, we report the genome-wide analysis of snRNAs that are bound to Gemin5 upon protein synthesis inhibition. Upon protein synthesis inhibition, the SMN complex that has a crucial role in the biogenesis of snRNPs dissociates into its subunits, leaving Gemin5 alone. The existence of these subunits was confirmed using a proteomics approach. As Gemin5 has been previously reported to be the RNA-binding protein of the SMN complex, we obtained the sequence of all Gemin5 immunoprecipitated snRNAs. We found that snRNAs that were accumulated on Gemin5 contained extra genomic sequences at the 3'-end. We were thus able to identify novel precursors of all the snRNAs that have not been identified previously. This study also provides a detailed method for the characterization of in vivo captured RNPs using a ribo-proteomics approach.
Project description:We report the CLIP-seq data of the non-canonical RNA-binding site of Gemin5. This region consists of two domains, RBS1 and RBS2, differing in their RNA-interaction features. Interestingly, the most abundant RNA target of the RBS1 polypeptide was the Gemin5 mRNA. Biochemical and functional characterization of this target demonstrated that RBS1 domain physically interacts with a stem-loop upregulating mRNA translation by counteracting the negative effect of Gemin5 protein on global protein synthesis. We propose that the RBS1 domain of Gemin5 performs a dual role on translation control, which depends on the target RNA, allowing fine-tune the availability of Gemin5 to play its multiple roles in gene expression control
Project description:Translation is a tightly regulated and is predominantly controlled at the level of its initiation. Initiation occurs in a cap-dependent manner. Under stress conditions when cap-dependent translation is hampered, internal ribosome entry sites (IRESes) allow for cap-independent translation of certain mRNAs. IRES-dependent translation is commonly regulated by RNA-interacting proteins, known as IRES trans-acting factors (ITAFs). In the present study, we searched for new IRESes by identifying 5’ untranslated regions (UTRs) bound by the ITAF hnRNPA1. Using a PAR-iCLIP approach, we found the mRNA of thioredoxin interacting protein (TXNIP) bound by hnRNPA1. Upon verification of an IRES element within the 5’UTR of TXNIP, we determined additional interacting proteins, which predominantly appeared to interact with the IRES-regulatory second half of the 5’UTR. Amongst these PTB, FBP3, and GEMIN5 emerged as functional ITAFs. Finally, we found that the TXNIP IRES-inhibitory effect of PTB was dominant over the activating effect of FBP3, while it succumbed to the stimulatory function of GEMIN5. In summary, we identified and characterized a novel IRES within the 5’UTR of TXNIP, which is regulated by the ITAFs PTB, FBP3, and GEMIN5.
Project description:Here we report the identification at a genome-wide scale of the mRNAs associated to polysomes in Gemin5-depleted cells relative to control cells. Among the polysomal Gemin5-enhanced mRNAs, we identified numerous transcripts belonging to two distinct families, which encode ribosomal proteins and histones.