Expression data from knockdown of IARS2 in A549 cells
Ontology highlight
ABSTRACT: Isoleucyl-tRNA synthetase 2, mitochondrial (IARS2) is a nuclear gene encoding a mitochondrial ARS. We used microarray analysis to identify the genes that are regulated by IARS2 in A549 cells.
Project description:Nicotine and nicotinic acetylcholine receptors (nAChRs) are considred to be involved in the progression of lung carcinomas. α5-nAChR is believed to be associated with lung cancer risk and onset, however its function and physiologic roles is far from clear. We use microarry to detail the global programme of gene expression underlying knockdown CHRNA5, encoding α5-nAChR, in human lung cancer A549 cells compared with control.
Project description:The Synthetase Sequestration Model (SSM) is a simplified translation model that considers explicitly two main steps in the process of tRNA aminoacylation: first, the tRNA is bound by the aminoacyl tRNA synthetase, and in a second step, the amino acid is attached to the tRNA. The tRNA then participates in the translation reaction, becoming deacylated as a result. The tRNA exists in states bound, charged and uncharged. In the bound state, the tRNA is bound to the synthetase but uncharged, i.e., the tRNA is sequestered by the synthetase. The model predicts how the balance between the three different tRNA states (empty, bound and charged) changes depending on aminoacyl tRNA synthetase availability.
Project description:rs12-04_rnanonpolya - nad9 knockdown 1 - Mitochondrial transcriptome regulation and coordination with the nucleus - Following a previously established strategy (Val et al., 2011, Nucleic Acids Res. 39, 9262–9274), we express, from an estradiol-inducible nuclear transgene, a trans-cleaving ribozyme directed against the nad9 mitochondrial mRNA and associated as a trailor sequence to a tRNA mimic. The latter serves as a shuttle and ensures mitochondrial uptake of the chimeric RNA through the natural tRNA import pathway. In mitochondria, the ribozyme triggers cleavage and degradation of the target mRNA. The impact of the nad9 mRNA knockdown on the overall plant transcriptome. Control samples correspond to plants not induced with estradiol.
Project description:Interactions between the gene products encoded by the mitochondrial and nuclear genomes play critical roles in normal eukaryotic cellular function. Here, we characterized the metabolic and transcriptional properties of A549 lung cancer cells and their isogenic mitochondrial DNA (mtDNA)-depleted rho zero counterparts grown in cell culture and as tumor xenografts in immune-deficient mice. A manuscript summarizing our conclusions is under review. Experiment Overall Design: A549 rho zero and their parental A549 cells were grown in culture and as xenografts in nude mice. All experiments conducted in culture were performed in triplicate (6 experiments total) and all experiments conducted in xenografts were performed in quadruplicate (8 experiments total). A manuscript summarizing our experimental design is under review.
Project description:HSPD1 knockdown was established in A549 cells using an shRNA approach. Secretomes from both shHSPD1-A549 and shControl-A549 cells were collected and subjected to label-free comparative proteome analysis using SWATH-MS.
Project description:rs12-06_a9-mrnonpolya - matr knockdown 1 - Mitochondrial transcriptome regulation and coordination with the nucleus - Following a previously established strategy (Val et al., 2011, Nucleic Acids Res. 39, 9262–9274), we express, from an estradiol-inducible nuclear transgene, a trans-cleaving ribozyme directed against the matR mitochondrial mRNA and associated as a trailor sequence to a tRNA mimic. The latter serves as a shuttle and ensures mitochondrial uptake of the chimeric RNA through the natural tRNA import pathway. In mitochondria, the ribozyme triggers cleavage and degradation of the target mRNA. The impact of the matR mRNA knockdown on the overall plant transcriptome. Control plants express either no ribozyme (C0a and C0b) or the shuttle RNA combined with a ribozyme that has no specific target in A. thaliana (SD).
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.
Project description:A subset of eukaryotic tRNAs is methylated in the anticodon loop to form the 3-methylcytosine (m3C) modification. In mammals, the number of tRNAs containing m3C has expanded to include mitochondrial (mt) tRNA-Ser-UGA and mt-tRNA-Thr-UGU. Whereas the enzymes catalyzing m3C formation in nuclear-encoded cytoplasmic tRNAs have been identified, the proteins responsible for m3C modification in mt-tRNAs are unknown. Here, we show that m3C formation in human mt-tRNAs is dependent upon the Methyltransferase-Like 8 (METTL8) enzyme. We find that METTL8 is a mitochondria-associated protein that interacts with mitochondrial seryl-tRNA synthetase along with mt-tRNAs containing m3C. Human cells deficient in METTL8 exhibit loss of m3C modification in mt-tRNAs but not nuclear-encoded tRNAs. Consistent with the mitochondrial import of METTL8, the formation of m3C in METTL8-deficient cells can be rescued by re-expression of wildtype METTL8 but not by a METTL8 variant lacking the N-terminal mitochondrial localization signal. Notably, METTL8-deficiency in human cells causes alterations in the native migration pattern of mt-tRNA-Ser-UGA suggesting a role for m3C in tRNA folding. Altogether, these findings demonstrate that METTL8 is required for m3C formation in mitochondrial tRNAs and uncover a potential role for m3C modification in mitochondrial tRNA structure.