Project description:Murine long-term hematopoietic stem cells (HSCs), short-term HSCs and multipotent progenitor cells (MPPs) were isolated from bone marrow and expression profiled on Affy chips. The behavior of maternal-specific imprinting genes, particularly in the H19-Igf2 locus, was focused on, to see if any might be involved in maintaining quiescence of long-term stem cells.
Project description:Long-term hematopoietic stem cells (HSCs), short-term HSCs and multipotent progenitor cells (MPPs) were isolated from bone marrow of four mouse strains (WT, H19-deletion, Igf1r-deletion, and double-deletion) and expression profiled with RNAseq. The behavior of the transcriptomes, and in particular the imprinted genes, was analyzed to see what might be involved in maintaining quiescence of long-term stem cells, and how H19 and Igf1r affected the expression of imprinted genes. Transcriptional profiling data of the same cells have been deposited in ArrayExpress under accession number E-MTAB-1644 (http://wwwdev.ebi.ac.uk/arrayexpress/experiments/E-MTAB-1644/).
Project description:Accurate translation of mRNAs into functional proteins is a fundamental process in all living organisms. In bacteria, in the early stage of translation elongation, peptidyl-tRNAs (pep-tRNAs) with short nascent chains frequently dissociate from the ribosome (pep-tRNA drop-off). The dissociated pep-tRNAs are deacylated and recycled by peptidyl-tRNA hydrolase (PTH), which is an essential enzyme in bacteria. Here, we establish a highly sensitive method for direct profiling of pep-tRNAs using RNA isolation method and mass spectrometry. We isolated each tRNA species with peptide from Escherichia coli pthts cells using reciprocal circulating chromatography and precisely analyzed their nascent peptides. As a result, we successfully detected 703 peptides consisted of 402 cognate peptides and 301 non-cognate peptides with single amino-acid substitution. Detailed analysis of individual pep-tRNAs revealed that most of the substitutions in the miscoded peptides take place at the C-terminal drop-off site. We further examined this observation using a reporter construct and found that the non-cognate pep-tRNAs produced by mistranslation rarely participate in the next round of elongation but dissociate from the ribosome, suggesting that pep-tRNA drop-off is an active mechanism by which the ribosome rejects miscoded pep-tRNAs in the early elongation, thereby contributing to quality control of protein synthesis after peptide bond formation.
Project description:Accurate translation of mRNAs into functional proteins is a fundamental process in all living organisms. In bacteria, in the early stage of translation elongation, peptidyl-tRNAs (pep-tRNAs) with short nascent chains frequently dissociate from the ribosome (pep-tRNA drop-off). The dissociated pep-tRNAs are deacylated and recycled by peptidyl-tRNA hydrolase (PTH), which is an essential enzyme in bacteria. Here, we establish a highly sensitive method for direct profiling of pep-tRNAs using RNA isolation method and mass spectrometry. We isolated each tRNA species with peptide from Escherichia coli pthts cells using reciprocal circulating chromatography and precisely analyzed their nascent peptides. As a result, we successfully detected 703 peptides consisted of 402 cognate peptides and 301 non-cognate peptides with single amino-acid substitution. Detailed analysis of individual pep-tRNAs revealed that most of the substitutions in the miscoded peptides take place at the C-terminal drop-off site. We further examined this observation using a reporter construct and found that the non-cognate pep-tRNAs produced by mistranslation rarely participate in the next round of elongation but dissociate from the ribosome, suggesting that pep-tRNA drop-off is an active mechanism by which the ribosome rejects miscoded pep-tRNAs in the early elongation, thereby contributing to quality control of protein synthesis after peptide bond formation.
Project description:Accurate translation of mRNAs into functional proteins is a fundamental process in all living organisms. In bacteria, in the early stage of translation elongation, peptidyl-tRNAs (pep-tRNAs) with short nascent chains frequently dissociate from the ribosome (pep-tRNA drop-off). The dissociated pep-tRNAs are deacylated and recycled by peptidyl-tRNA hydrolase (PTH), which is an essential enzyme in bacteria. Here, we establish a highly sensitive method for direct profiling of pep-tRNAs using RNA isolation method and mass spectrometry. We isolated each tRNA species with peptide from Escherichia coli pthts cells using reciprocal circulating chromatography and precisely analyzed their nascent peptides. As a result, we successfully detected 703 peptides consisted of 402 cognate peptides and 301 non-cognate peptides with single amino-acid substitution. Detailed analysis of individual pep-tRNAs revealed that most of the substitutions in the miscoded peptides take place at the C-terminal drop-off site. We further examined this observation using a reporter construct and found that the non-cognate pep-tRNAs produced by mistranslation rarely participate in the next round of elongation but dissociate from the ribosome, suggesting that pep-tRNA drop-off is an active mechanism by which the ribosome rejects miscoded pep-tRNAs in the early elongation, thereby contributing to quality control of protein synthesis after peptide bond formation.
Project description:Accurate translation of mRNAs into functional proteins is a fundamental process in all living organisms. In bacteria, in the early stage of translation elongation, peptidyl-tRNAs (pep-tRNAs) with short nascent chains frequently dissociate from the ribosome (pep-tRNA drop-off). The dissociated pep-tRNAs are deacylated and recycled by peptidyl-tRNA hydrolase (PTH), which is an essential enzyme in bacteria. Here, we establish a highly sensitive method for direct profiling of pep-tRNAs using RNA isolation method and mass spectrometry. We isolated each tRNA species with peptide from Escherichia coli pthts cells using reciprocal circulating chromatography and precisely analyzed their nascent peptides. As a result, we successfully detected 703 peptides consisted of 402 cognate peptides and 301 non-cognate peptides with single amino-acid substitution. Detailed analysis of individual pep-tRNAs revealed that most of the substitutions in the miscoded peptides take place at the C-terminal drop-off site. We further examined this observation using a reporter construct and found that the non-cognate pep-tRNAs produced by mistranslation rarely participate in the next round of elongation but dissociate from the ribosome, suggesting that pep-tRNA drop-off is an active mechanism by which the ribosome rejects miscoded pep-tRNAs in the early elongation, thereby contributing to quality control of protein synthesis after peptide bond formation.
Project description:Duck reovirus (DRV) is well-studied aquatic bird virus belonging to the Orthoreovirus genus of the Reoviridae family. The bursa of Fabricius is an immunologically organ against virus invasion. However, the responses of the bursa of Fabricius of Cairna moschata to DRV infection are largely unknown. To investigate the immune responses, the proteomes from the control and two DRV strain infected samples (NH and DJ) were compared. In total, 7075 protein were identified, of which 5625 protein were quantified. A number of differentially expressed proteins (DEPs), including 210 DEPs under the HN10 infection and 55 DEPs under the JD10 infection, were identified. Protein network analysis showed that the DEPs enriched in the serine protease system and the innate immune response clusters. For the serine protease systems, coagulation factor IX, three chains of fibrinogen, and complement C8, C5, and C2s were significantly up-regulated, suggesting that the serine protease-mediated immune might be involved in the responses to the HN10 infection. For the innate and adaptive immune system, RIG-I, MDA5, MAPK20, and IRF3 were significantly up-regulated, indicating their important role in the reorganization of invaded virus. Furthermore, the DEPs among different visceral organs (liver, spleen, and the bursa of Fabricius) were compared. coagulation factor IX was significantly up-regulated in the bursa of fabricius, not in the liver and spleen samples, suggesting an important role of the bursa of fabricius in antivirus. Our data may give a comprehensive resource for investigating the regulation mechanism involved in the responses of the bursa of Fabricius of duck to the DRV infections.