U6 snRNA m6A modification is required for accurate and efficient splicing of C. elegans and human pre-mRNAs
Ontology highlight
ABSTRACT:
PROVIDER: PRJEB65287 | ENA |
REPOSITORIES: ENA
Similar Datasets
Project description:pre-mRNA splicing is a critical feature of eukaryotic gene expression. Both cis- and trans-splicing rely on accurately recognising splice site sequences by spliceosomal U snRNAs and associated proteins. Spliceosomal snRNAs carry multiple RNA modifications with the potential to affect different stages of pre-mRNA splicing. Here, we show that the conserved U6 snRNA m6A methyltransferase METT-10 is required for accurate and efficient cis- and trans-splicing of C. elegans pre-mRNAs. The absence of METT-10 in C. elegans and METTL16 in humans primarily leads to alternative splicing at 5' splice sites with an adenosine at +4 position. In addition, METT-10 is required for splicing of weak 3' cis- and trans-splice sites. We identified a significant overlap between METT-10 and the conserved splicing factor SNRNP27K in regulating 5' splice sites with +4A. Finally, we show that editing endogenous 5' splice site +4A positions to +4U restores splicing to wild-type positions in a mett-10 mutant background, supporting a direct role for U6 snRNA m6A modification in 5' splice site recognition. We conclude that the U6 snRNA m6A modification is important for accurate and efficient pre-mRNA splicing.
| S-EPMC11347140 | biostudies-literature
Project description:Maintenance of the intracellular levels of the methyl donor S-adenosylmethionine (SAM) is essential for a wide variety of biological processes. We demonstrate that the N6-adenosine methyltransferase METTL16 regulates expression of MAT2A, which encodes the only SAM synthetase expressed in most cells. Upon SAM depletion by methionine starvation, cells induce MAT2A expression by enhanced splicing of a retained intron. Induction requires METTL16 and its methylation substrate, a vertebrate conserved hairpin (hp1) in the MAT2A 3´ UTR. Increasing METTL16 occupancy on the MAT2A 3´ UTR is sufficient to induce efficient splicing. We propose that under SAM-limiting conditions, METTL16 occupancy on hp1 increases due to inefficient enzymatic turnover, which in turn promotes MAT2A splicing. Interestingly, human and S. pombe METTL16 methylate the U6 spliceosomal snRNA at a sequence identical to hp1. These observations suggest that the conserved U6 snRNA methyltransferase evolved an additional function in vertebrates to regulate SAM homeostasis.
2017-05-18 | GSE90914 | GEO
Project description:Role of TFIP11 in U6 snRNA modification and splicing efficiency
| PRJNA657749 | ENA
Project description:RNA ligation precedes U6 snRNA/LINE-1 retrotransposition
| PRJNA486226 | ENA
Project description:Mpn1 proteins are evolutionarily conserved exonucleases that modify spliceosomal U6 small nuclear RNAs (snRNAs) post-transcriptionally. Mutations in the human MPN1 gene are associated to the genodermatosis Clericuzio-type poikiloderma with neutropenia (PN). Mpn1 deficiency leads to aberrant U6 3M-bM-^@M-^Y end processing and accelerated U6 decay through unknown molecular mechanisms. Here we show that in mpn1M-NM-^T fission yeast cells U6 is barely bound by the protective Lsm2-8 complex, undergoes extensive oligoadenylation and is degraded by the nuclear RNA exonuclease Rrp6 independently of the poly(A) polymerase Cid14/Trf4. Mpn1 processes U6 in a spliceosome-dependent manner, as mutant U6 molecules that fail to join the spliceosome are not substrates for Mpn1. Moreover, human U6atac, the U6-like snRNA of the minor spliceosome, is a novel substrate for hMpn1. We unveil mechanistic details of a new U6 degradation pathway and further corroborate the notion that inefficient canonical and minor pre-mRNA splicing promotes PN. the 3' termini of U6 or tagged-U6 species from the indicated mutant cells were compared to wt yeast strain
2014-08-08 | E-GEOD-60195 | biostudies-arrayexpress
Project description:Mpn1 proteins are evolutionarily conserved exonucleases that modify spliceosomal U6 small nuclear RNAs (snRNAs) post-transcriptionally. Mutations in the human MPN1 gene are associated to the genodermatosis Clericuzio-type poikiloderma with neutropenia (PN). Mpn1 deficiency leads to aberrant U6 3’ end processing and accelerated U6 decay through unknown molecular mechanisms. Here we show that in mpn1Δ fission yeast cells U6 is barely bound by the protective Lsm2-8 complex, undergoes extensive oligoadenylation and is degraded by the nuclear RNA exonuclease Rrp6 independently of the poly(A) polymerase Cid14/Trf4. Mpn1 processes U6 in a spliceosome-dependent manner, as mutant U6 molecules that fail to join the spliceosome are not substrates for Mpn1. Moreover, human U6atac, the U6-like snRNA of the minor spliceosome, is a novel substrate for hMpn1. We unveil mechanistic details of a new U6 degradation pathway and further corroborate the notion that inefficient canonical and minor pre-mRNA splicing promotes PN.
2014-08-08 | GSE60195 | GEO
Project description:The La-related protein LARP7 has been mainly described as a component of the 7SK small nuclear ribonucleoprotein (snRNP) complex, which negatively regulates RNA polymerase II by sequestering the positive transcription elongation factor b (P-TEFb). In our studies, we discovered a novel, 7SK snRNP-independent function of LARP7. We show that LARP7 interacts with the U6 spliceosomal RNA as well as with the small nucleolar RNAs (snoRNAs) directing the 2'-O-methylations of U6. To investigate the relevance of this interaction, U6 or U2 snRNAs were purified from total RNA by pulldown of biotinylated antisense oligonucleotides and the occurence of 2’-O-methylations was investigated by RiboMeth-seq analysis. A comparison between U6 and U2 snRNA isolated from HEK293 wildtype or LARP7 knockout cell lines revealed that 2’-O-methylations of the U6 snRNA are specifically lost in the absence of LARP7. Alazami syndrome is a form of primary dwarfism associated with mutations in the LARP7 gene. RiboMeth-seq analyses performed with RNA isolated from blood samples of two Alazami patients or healthy parents as well as from B-lymphoblastoid cell lines (B-LCLs) derived from an Alazami patient and from a healthy parent confirmed the impact of mutant LARP7 protein variants on the 2’-O-methylation profile of the U6 snRNA.
2020-02-03 | GSE126593 | GEO
Project description:How the relatively evolutionarily conserved spliceosome is able to manage the enormously expanded number of splicing events that occur in humans (~200,000 vs. ~400 reported for yeast) is not well understood. Here, we show deposition of one RNA modification-N2-methylguanosine (m2G)-on the G72 nucleoside of U6 snRNA (known to function as the catalytic center of the spliceosome) results in profoundly increased pre-mRNA splicing activity in human cells. This U6 m2G72 modification is conserved among vertebrates. Further, we demonstrate that THUMPD2 is the methyltransferase responsible for U6 m2G72 and show that it interacts with an auxiliary protein (TRMT112) to specifically recognize both sequence and structural elements of U6. THUMPD2 KO blocks U6 m2G72 and down-regulates the pre-mRNA splicing activity of major spliceosome, yielding thousands of changed alternative splicing events of endogenous pre-mRNAs. Notably, the aberrantly spliced pre-mRNA population of the THUMPD2 KO cells elicits the nonsense-mediated mRNA decay (NMD) pathway and restricts cell proliferation. We also show that THUMPD2-mediated control of the U6 m2G72 modification is associated with age-related macular degeneration and retinal function. Our study thus demonstrates how an RNA epigenetic modification of the major spliceosome differentially regulates global mRNA splicing and impacts physiology and disease.
2024-01-02 | GSE236689 | GEO
Project description:Modified nucleotides in non-coding RNAs, such as tRNAs and snRNAs, represent an important layer of gene expression regulation through their ability to fine-tune mRNA maturation and translation. Dysregulation of such modifications and the enzymes installing them have been linked to various human pathologies including neurodevelopmental disorders and cancers. Several methyltransferases (MTases) are regulated allosterically by human TRMT112 (Trm112 in Saccharomyces cerevisiae), but the interactome of this regulator and targets of its interacting MTases remain incompletely characterized. Here, we have investigated the interaction network of human TRMT112 in intact cells and identify three poorly characterized putative MTases (TRMT11, THUMPD3 and THUMPD2) as direct partners. We demonstrate that these three proteins are active N2-methylguanosine (m2G) MTases and that TRMT11 and THUMPD3 methylate positions 10 and 6 of tRNAs, respectively. For THUMPD2, we discovered that it directly associates with the U6 snRNA, a core component of the catalytic spliceosome, and is required for the formation of m2G, the last “orphan” modification in U6 snRNA. Furthermore, our data reveal the combined importance of TRMT11 and THUMPD3 for optimal protein synthesis and cell proliferation as well as a role for THUMPD2 in fine-tuning pre-mRNA splicing.
2023-05-17 | GSE219260 | GEO
Project description:The N6-methyladenosine modification at position 43 (m6A43) of U6 snRNA is catalyzed by METTL16, and is important for the 5'-splice site recognition by U6 snRNA during pre-mRNA splicing. Human METTL16 consists of the N-terminal methyltransferase domain (MTD) and the C-terminal vertebrate conserved region (VCR). While the MTD has an intrinsic property to recognize a specific sequence in the distinct structural context of RNA, the VCR functions have remained uncharacterized. Here, we present structural and functional analyses of the human METTL16 VCR. The VCR increases the affinity of METTL16 toward U6 snRNA, and the conserved basic region in VCR is important for the METTL16-U6 snRNA interaction. The VCR structure is topologically homologous to the C-terminal RNA binding domain, KA1, in U6 snRNA-specific terminal uridylyl transferase 1 (TUT1). A chimera of the N-terminal MTD of METTL16 and the C-terminal KA1 of TUT1 methylated U6 snRNA more efficiently than the MTD, indicating the functional conservation of the VCR and KA1 for U6 snRNA biogenesis. The VCR interacts with the internal stem-loop (ISL) within U6 snRNA, and this interaction would induce the conformational rearrangement of the A43-containing region of U6 snRNA, thereby modifying the RNA structure to become suitable for productive catalysis by the MTD. Therefore, the MTD and VCR in METTL16 cooperatively facilitate the m6A43 U6 snRNA modification.
| S-EPMC7229813 | biostudies-literature