Project description:The mRNA cap structure consists of the m7G "cap0" linked to the 5'-most nucleotide of the initial mRNA. The first two nucleotides of mRNA can be 2'-O-Ribose modified to form cap1 or cap2 structures. Here, mRNA was sequenced after CLIP with tagged recombinant CMTR1 and compared to input RNA.
Project description:The mRNA cap structure consists of the m7G "cap0" linked to the 5'-most nucleotide of the initial mRNA. The first two nucleotides of mRNA can be 2'-O-Ribose modified to form cap1 or cap2 structures. Here, mRNA was sequenced after CLIP with tagged recombinant CMTR2 enzyme and compared to input RNA.
Project description:The analysis of capped RNAs by massively parallel sequencing has identified a large number of previously unknown transcripts, some of which are small RNAs and others are 5M-bM-^@M-^Y truncated forms of RefSeq genes. The latter may be generated by endonuclease cleavage or by stalling of Xrn1 at defined sites. With the exception of promoter-proximal transcripts the caps on all of these are added post-transcriptionally by a cytoplasmic capping enzyme complex that includes capping enzyme and a kinase that converts 5M-bM-^@M-^Y-monophosphate ends to a diphosphate capping substrate. We previously described a modified form of capping enzyme with dominant negative activity against cytoplasmic capping (DN-cCE). A tet-inducible form of this was used to identify substrates for cytoplasmic capping by treating cytoplasmic RNA from control and induced cells with and without Xrn1. Surviving RNA was analyzed on Affymetrix Human Exon 1.0 arrays and scored for changes in probe intensity as a function of its position on each RefSeq gene to derive a factor (alpha) that could be compared between sets. Notably, transcriptome-wide changes were not evident unless RNA was treated with Xrn1. This analysis identified 2,666 uncapped mRNAs in uninduced cells, 672 mRNAs that appeared in the uncapped pool in cells expressing DN-cCE, and 835 mRNAs that were in both populations. Changes in cap status of 10 re-capping targets and 5 controls were assessed by 3 independent measures; susceptibility to Xrn1, recovery with a biotin-tagged DNA primer after ligating a complementary RNA oligonucleotide to uncapped 5M-bM-^@M-^Y ends, and binding or exclusion from a high affinity cap-binding matrix comprised of immobilized eIF4E and the corresponding binding domain of eIF4G. 3 biological replicates of 4 different samples comparing XRN1 treatment/non-treatment and Dox induction/non-induction of K294A
Project description:The analysis of capped RNAs by massively parallel sequencing has identified a large number of previously unknown transcripts, some of which are small RNAs and others are 5’ truncated forms of RefSeq genes. The latter may be generated by endonuclease cleavage or by stalling of Xrn1 at defined sites. With the exception of promoter-proximal transcripts the caps on all of these are added post-transcriptionally by a cytoplasmic capping enzyme complex that includes capping enzyme and a kinase that converts 5’-monophosphate ends to a diphosphate capping substrate. We previously described a modified form of capping enzyme with dominant negative activity against cytoplasmic capping (DN-cCE). A tet-inducible form of this was used to identify substrates for cytoplasmic capping by treating cytoplasmic RNA from control and induced cells with and without Xrn1. Surviving RNA was analyzed on Affymetrix Human Exon 1.0 arrays and scored for changes in probe intensity as a function of its position on each RefSeq gene to derive a factor (alpha) that could be compared between sets. Notably, transcriptome-wide changes were not evident unless RNA was treated with Xrn1. This analysis identified 2,666 uncapped mRNAs in uninduced cells, 672 mRNAs that appeared in the uncapped pool in cells expressing DN-cCE, and 835 mRNAs that were in both populations. Changes in cap status of 10 re-capping targets and 5 controls were assessed by 3 independent measures; susceptibility to Xrn1, recovery with a biotin-tagged DNA primer after ligating a complementary RNA oligonucleotide to uncapped 5’ ends, and binding or exclusion from a high affinity cap-binding matrix comprised of immobilized eIF4E and the corresponding binding domain of eIF4G.
Project description:Measurement of capping efficiency (by 5'CAP and 5'noCAP sequencing) in male (S2) and female (Kc) Drosophila melanogaster cells upon depletion of MSL1 by dsRNA compared to the eGFP RNAi control. The measurement of capping efficiency was combined with gene expression measurement by strand specific RNA-Seq in female (Kc) Drosophila melanogaster cells
Project description:We discovered that the RNA helicase DHX15 is a regulator of the methyltransferase CMTR1. To determine the biological consequences of this interaction we overexpressed CMTR1 or a mutated CMTR1 (2LA)that does not bind DHX15, in the human breast cancer cell line HCC1806. To assess the effects of the DHX15-CMTR1 interaction on translation, polysomes were separated on a sucrose gradient and sequencing libraries generated from the polysomal and input RNA. We found that the DHX15-CMTR1 interaction controls ribosome loading of a subset of mRNAs and impacts on cell proliferation.
Project description:Formaldehyde crosslinking and Proximity-dependent biotinylation methods were applied to study the cytoplasmic capping enzyme interactome via 1D-LC-MS/MS. The raw data were searched against Uniprot human database modified to contain our designed protein sequences using the Thermo Proteome Discoverer software (v 1.4.1.14).
Project description:CMTR1, also called IFN-stimulated gene 95 kDa protein (ISG95), is elevated by viral infection in a variety of cells. However, the function of CMTR1 in colorectal cancer (CRC), especially its role in tumorigenesis and immune regulation, remains unclear. Here, we first identified CMTR1 as a novel oncogene in colorectal cancer. Based on The Cancer Genome Atlas (TCGA) database exploration and human tissue microarray (TMA) analysis, we found that CMTR1 expression was markedly higher in colorectal cancer tissues compared to that in adjacent normal tissues. High CMTR1 was correlated with poor prognosis of colorectal cancer patients. Knockdown (KD) of CMTR1 significantly suppressed cell proliferation and tumorigenicity both in vitro and in vivo, whereas overexpression of CMTR1 exhibited the opposite effects. KEGG analysis revealed that the JAK/STAT signaling pathway was differentially enriched in colorectal cancer cells with CMTR1 KD. Mechanistically, repression of CMTR1 influenced RNAPII recruitment to the TSS and repression of STAT3 expression and activation. Furthermore, PD1 blockade immunotherapy was prominently enhanced with CMTR1 KD by increased infiltration of CD8+ T cells into tumor microenvironment. Overall, it appears that CMTR1 plays a key role in regulating tumor cell proliferation and antitumor immunity.