ArgRS, MetRS, and SRRM2 dependent changes in mRNA splicing and exon usage
Ontology highlight
ABSTRACT:
ORGANISM(S): Homo sapiens
PROVIDER: GSE165513 | GEO | 2023/04/03
REPOSITORIES: GEO
Similar Datasets
Project description:Arginine is associated with inflammation, cancer, and amino acid signaling, in part through the mTORC1 pathway. In cell-based assays and in the mouse, we found that arginine regulates nuclear levels of arginyl-tRNA synthetase (ArgRS), and that arginine depletion and inflammation reduced nuclear ArgRS in vivo. In the nucleus, ArgRS interacted and co-localized with the spliceosomal Serine/Arginine Repetitive Matrix Protein 2 (SRRM2) that is crucial for the formation of nuclear speckle condensates. ArgRS mRNA silencing changed specific splice junction usages, and these inversely correlated with SRRM2-induced usage changes of the same junctions. The prominently affected genes encompassed components of the mTORC1 pathway and showed ArgRS, arginine, and SRRM2 are tied together as upstream regulators of nuclear condensate trafficking related to the physiological response to inflammatory injury. This study is the first to demonstrate a regulatory role for an aaRS in shaping nuclear condensate dynamics and RNA splicing.
2023-04-14 | PXD024091 | Pride
Project description:Cells respond to perturbations like inflammation by sensing changes in metabolite levels. Especially prominent is arginine, which has known connections to the inflammatory response. Here, we found that depletion of arginine during inflammation decreased levels of a nuclear form of arginyl-tRNA synthetase (ArgRS). Surprisingly, we found that nuclear ArgRS interacts and co-localizes with serine/arginine repetitive matrix protein 2 (SRRM2), a spliceosomal and nuclear speckle protein, and that decreased levels of nuclear ArgRS correlated with changes in condensate-like nuclear trafficking of SRRM2 and splice-site usage in certain genes. These splice-site usage changes cumulated in the synthesis of different protein isoforms that altered cellular metabolism and peptide presentation to immune cells. Our findings uncover a novel mechanism whereby a tRNA synthetase cognate to a key amino acid that is metabolically controlled during inflammation modulates the splicing machinery.
2023-04-14 | PXD036232 | Pride
Project description:Prior work revealed nuclear-localized aminoacyl-tRNA synthetases (aaRSs) that checked newly synthesized tRNAs for charging before export to the cytoplasm. To reveal other functions, we sought to identify nuclear proteins that interact with arginyl-tRNA synthetase (ArgRS) in the nucleus. Serine/Arginine Repetitive Matrix Protein 2 (SRRM2), which is stored with RNA splicing apparatus components in nuclear speckle condensates, was found as a consistent interaction partner that co localized with SRRM2 ArgRS in nuclear speckles. Dynamic photo-bleaching experiments showed that, consistent with condensate properties, SRRM2 has a fluctuating appearance in speckles. Knock down of ArgRS impeded SRRM2 speckle trafficking and, coincidently, altered splicing processing of pre-mRNA transcripts. Among the altered spliced variants, those of tRNA synthetase family members were prominent. Thus, nuclear ArgRS shapes the dynamics of a protein in class of nuclear condensates. Also, the work expands the repertoire of nuclear tRNA synthetase roles to include regulation of RNA splicing, including of aaRS family member transcripts.
2023-04-14 | PXD015692 | Pride
Project description:Nuclear speckles (NSs) are nuclear biomolecular condensates that are postulated to arise through liquid-liquid phase separation (LLPS), although the detailed underlying forces driving NS formation remain elusive. SRRM2 and SON are 2 non-redundant scaffold proteins for NSs. How each individual protein governs assembly of NS protein network and the functional relationship between SRRM2 and SON are largely unknown. Here, we uncover immiscible multiphase of SRRM2 and SON within NSs. SRRM2 and SON are functionally independent, specifically regulating alternative splicing of subsets of mRNA targets, respectively. We further uncover that SRRM2 forms multicomponent liquid phase in cells to drive NS subcompartmentalization, which is reliant on homotypic interaction and heterotypic non-selective protein-RNA complex coacervation-driven multicomponent LLPS. SRRM2 RS domains form high-order oligomers, and can be replaced by oligomerizable synthetic modules, the serine residues within the RS domains, however, play an irreplaceable role in fine-tuning the liquidity of NSs.
2024-01-31 | GSE242898 | GEO
Project description:We reported the joint SRRM1/2 regulation is not the major mechanism of SRRM2-mediated alternative splicing, and that maintenance of splicing condensates by SRRM2 is important for proper alternative splicing. We knocked SRRM1/2 down with three different shRNAs, performed RNA-seq and derived the differential alternative splicing events (DASEs) using rMATS. DASEs of SRRM1/2 were largely different with little overlap, and displayed a different splicing pattern. SRRM2 deficiency induces skipping of cassette exons with short introns and weak 5’ splice. Nearly 25% of the skipped events upon SRRM2 knockdown were unannotated. More than 40% of validated DASEs upon SRRM2 suppression were associated with protein domain change (>50% domain removed by splicing). Domain changes, and especially large region removal by multiple exon skipping is a significant mechanism for protein dysfunction. Thus, alternative splicing is the major mechanism for the maintenance of protein function and cell homeostasis by SRRM2.
2022-08-30 | GSE199720 | GEO
Project description:The nucleus of higher eukaryotes is a highly compartmentalized and dynamic organelle consisting of several biological condensates that regulate gene expression at multiple levels. First reported more than 100 years ago by Ramón y Cajal, nuclear speckles (NS) are among the most prominent of such condensates, which were independently rediscovered multiple times and are also known as interchromatin granule clusters (ICGs), splicing speckles, or SC35 domains. Despite their prevalence, research on the function of NS is virtually restricted to colocalization analyses, since an organizing core, without which NS cannot form, remains unidentified. The monoclonal antibody SC35, which was raised against a spliceosomal extract, is a frequently used reagent to mark NS since its debut in 1990. Despite its prolific use, and the consensus regarding its primary target as SRSF2, clear inconsistencies between observations made with mAb SC35, and transgenic SRSF2 constructs in the same experiment are noted. Intrigued by these disparities, we carried out a systematic re-characterization of this monoclonal antibody and its cellular targets. Unexpectedly, we found no evidence for SC35 mAb recognizing SRSF2 in human cells. In contrast, our results show that the 35 kDa namesake protein recognized by SC35 mAb is SRSF7, a related but distinct SR protein. More importantly, using mass-spectrometry, CRISPR-mediated knock-ins, immunoblotting and fluorescence microscopy, we show that the main target of SC35 mAb is SRRM2, a large (300 kDa), spliceosome-associated protein with prominent intrinsically disordered regions (IDRs) that sharply localizes to NS. Analysis of protein length evolution among metazoa revealed a peculiar IDR extension specifically for SRRM2 and SON in vertebrates, a hallmark of condensate formation. Combining these results, we tested a long-standing question in the study of NS: whether NS are formed around a specific core, or various SR-proteins self-assemble into a phase-separated compartment without the need for a defined core. Here we show that, the elusive core of NS is formed by SON and SRRM2, since depletion of SON leads only to a partial disassembly of NS, while combined depletion of SON together with SRRM2, but not other NS associated factors, or depletion of SON in a cell line where IDRs of SRRM2 are genetically deleted, leads to a near-complete dissolution of NS. This work, therefore, paves the way to study the role of NS under diverse physiological and stress conditions.
2020-10-26 | PXD021814 | Pride
Project description:Srrm2 splicing factor is a novel gene implicated in developmental disorders and diseases. However, the role of Srrm2 in early mammalian development remains unexplored. Here, we show that Srrm2 expression dosage is critical for maintaining embryonic stem cell pluripotency and cell identity. Srrm2 heterozygosity promotes loss of stemness characterized by the coexistence of cells expressing naive and formative markers, together with large gene expression shifts, including in serum-response transcription factor targets and differentiation-related genes. Depletion of Srrm2 by RNA interference in embryonic stem cells identified splicing misregulation of specific genes, often linked to exon skipping. These results show that Srrm2 dosage is key in controlling stemness and cell fate decisions. Our findings unveil Srrm2’s molecular and cellular implications in development, shedding light on the involvement of splicing regulators in early embryogenesis, developmental diseases and tumorigenesis.
2024-04-12 | GSE243431 | GEO
Project description:Srrm2 splicing factor is a novel gene implicated in developmental disorders and diseases. However, the role of Srrm2 in early mammalian development remains unexplored. Here, we show that Srrm2 expression dosage is critical for maintaining embryonic stem cell pluripotency and cell identity. Srrm2 heterozygosity promotes loss of stemness characterized by the coexistence of cells expressing naive and formative markers, together with large gene expression shifts, including in serum-response transcription factor targets and differentiation-related genes. Depletion of Srrm2 by RNA interference in embryonic stem cells identified splicing misregulation of specific genes, often linked to exon skipping. These results show that Srrm2 dosage is key in controlling stemness and cell fate decisions. Our findings unveil Srrm2’s molecular and cellular implications in development, shedding light on the involvement of splicing regulators in early embryogenesis, developmental diseases and tumorigenesis.
2024-04-12 | GSE243429 | GEO
Project description:Srrm2 splicing factor is a novel gene implicated in developmental disorders and diseases. However, the role of Srrm2 in early mammalian development remains unexplored. Here, we show that Srrm2 expression dosage is critical for maintaining embryonic stem cell pluripotency and cell identity. Srrm2 heterozygosity promotes loss of stemness characterized by the coexistence of cells expressing naive and formative markers, together with large gene expression shifts, including in serum-response transcription factor targets and differentiation-related genes. Depletion of Srrm2 by RNA interference in embryonic stem cells identified splicing misregulation of specific genes, often linked to exon skipping. These results show that Srrm2 dosage is key in controlling stemness and cell fate decisions. Our findings unveil Srrm2’s molecular and cellular implications in development, shedding light on the involvement of splicing regulators in early embryogenesis, developmental diseases and tumorigenesis.
2024-04-12 | GSE243432 | GEO
Project description:Papillary thyroid carcinoma (PTC) displays strong but so far largely uncharacterized heritability. Here we studied genetic predisposition in a family with six affected individuals. We genotyped all available family members and conducted whole exome sequencing of blood DNA from two affected individuals. Haplotype analysis and other genetic criteria narrowed our list of candidates to a germline variant in the serine/arginine repetitive matrix 2 gene (SRRM2). This heterozygous variant, c.1037C>T (Ser346Phe or S346F; rs149019598) cosegregated with PTC in the family. It was not found in 138 other PTC families. It was found in 7/1,170 sporadic PTC cases and in 0/1,404 controls (p=0.004). The encoded protein SRRM2 (also called SRm300) is part of the RNA splicing machinery. To evaluate the possibility that the S346F missense mutation affects alternative splicing, we compared RNA-Seq data in leukocytes from three mutation carriers and three controls. Significant differences in alternative splicing were identified for 1,642 exons, of which a subset of 7 exons was verified experimentally. The results confirmed a higher ratio of inclusion of exons in mutation carriers. These data suggest that the S346F mutation in SRRM2 predisposes to PTC by affecting alternative splicing of unidentified downstream target genes.
2017-08-14 | GSE68058 | GEO