http://www.bibsonomy.org/burst/user/mikromolbio/MessengerBibSonomy BuRST Feed for /user/mikromolbio/Messenger2008-10-12T19:29:51+02:00http://www.bibsonomy.org/bibtex/27ffd100e93e552721654848a86efd795/mikromolbiomikromolbio2008-05-07T15:52:44+02:00Gene_Expression_Regulation Two-Dimensional Gel Electrophoresis Host_Factor_1_Protein Rhodobacter_sphaeroides Bacterial_Proteins Reactive_Oxygen_Species Catalase Hydrogen_Peroxide Singlet_Oxygen Sigma_Factor Protein_Biosynthesis RNA Cations IFZ Proteome Light Bacterial Mutation Transcription_Factors Divalent Messenger <span style="color:#555555;">Jens <a href="http://www.bibsonomy.org/author/Glaeser">Glaeser</a> und Monica <a href="http://www.bibsonomy.org/author/Zobawa">Zobawa</a> und Friedrich <a href="http://www.bibsonomy.org/author/Lottspeich">Lottspeich</a> und Gabriele <a href="http://www.bibsonomy.org/author/Klug">Klug</a> </span><em>Journal of proteome research</em><em>July2007. </em><em>PMID: 17536848 . </em>Wed May 07 15:52:44 CEST 2008Journal of proteome researchJulyPMID: 175368482460-71Protein synthesis patterns reveal a complex regulatory response to singlet oxygen in Rhodobacter62007Gene_Expression_Regulation Two-Dimensional Gel Electrophoresis Host_Factor_1_Protein Rhodobacter_sphaeroides Bacterial_Proteins Reactive_Oxygen_Species Catalase Hydrogen_Peroxide Singlet_Oxygen Sigma_Factor Protein_Biosynthesis RNA Cations IFZ Proteome Light Bacterial Mutation Transcription_Factors Divalent Messenger Singlet oxygen (1O2) is a stress factor and signal in the facultative phototrophic bacterium Rhodobacter sphaeroides. In vivo protein labeling with L-[35S]-methionine and analysis by two-dimensional gel electrophoresis revealed that the synthesis of 61 proteins was changed in response to 1O2. After 1O2 treatment, protein synthesis patterns were distinct from those after H2O2 treatment but similar to those after high light exposure. This indicates regulatory mechanisms selective for different reactive oxygen species (ROS) and a response to light partly mediated by 1O2. Analysis of mutant strains support that the response to 1O2 is regulated mainly by rpoE (sigma E), but also a modulation of the sigma E dependent response by other factors and the existence of sigma E independent responses. The involvement of the RNA chaperon Hfq in the 1O2 response implies a role of small regulatory RNAs.http://www.bibsonomy.org/bibtex/2dca52bc2607846f74bf0d7984035d738/mikromolbiomikromolbio2008-05-07T15:52:44+02:00Amino_Acid_Sequence Genetic_Vectors Cells Molecular_Sequence_Data Cultured Eukaryotic_Cells Lysine RNA-Binding_Proteins Archaeal Sequence_Homology Nucleic_Acid_Conformation Base_Sequence Halobacterium Archaeal_Proteins RNA IFZ Ribonucleases Protein_Processing Post-Translational Nucleic_Acid Ligands Peptide_Initiation_Factors Messenger <span style="color:#555555;">Steffen <a href="http://www.bibsonomy.org/author/Wagner">Wagner</a> und Gabriele <a href="http://www.bibsonomy.org/author/Klug">Klug</a> </span><em>The Journal of biological chemistry</em><em>May2007. </em><em>PMID: 17369252 . </em>Wed May 07 15:52:44 CEST 2008The Journal of biological chemistryMayPMID: 1736925213966-76An archaeal protein with homology to the eukaryotic translation initiation factor 5A shows ribonucleolytic activity2822007Amino_Acid_Sequence Genetic_Vectors Cells Molecular_Sequence_Data Cultured Eukaryotic_Cells Lysine RNA-Binding_Proteins Archaeal Sequence_Homology Nucleic_Acid_Conformation Base_Sequence Halobacterium Archaeal_Proteins RNA IFZ Ribonucleases Protein_Processing Post-Translational Nucleic_Acid Ligands Peptide_Initiation_Factors Messenger To identify proteins that are involved in RNA degradation and processing in Halobacterium sp. NRC-1, we purified proteins with RNA-degrading activity by classical biochemical techniques. One of these proteins showed strong homology to the eukaryotic initiation factor 5A (eIF-5A) and was accordingly named archaeal initiation factor 5A (aIF-5A). Eukaryotic IF-5A is known to be involved in mRNA turnover and to bind RNA. Hypusination of eIF-5A is required for sequence-specific binding of RNA. This unique post-translational modification is restricted to Eukarya and Archaea. The exact function of eIF-5A in RNA turnover remained obscure. Here we show for the first time that aIF-5A from Halobacterium sp. NRC-1 exhibits RNA cleavage activity, preferentially cleaving adjacent to A nucleotides. Detectable RNA binding could be shown for aIF-5A purified from Halobacterium sp. NRC-1 but not from Escherichia coli, while both proteins possess RNA cleavage activity, indicating that hypusination of aIF-5A is required for RNA binding but not for its RNA cleavage activity. Furthermore, we show that the hypusinated form of eIF-5A also shows RNase activity while the unmodified protein does not. Charged amino acids in the N-terminal domain of aIF-5A as well as in the C-terminal domain, which is highly similar to the cold shock protein A (CspA), an RNA chaperone of E. coli, are important for RNA cleavage activity. Moreover our results reveal that activity of aIF-5A depends on its oligomeric state.http://www.bibsonomy.org/bibtex/2878c84029d2104ff7f5177044c52c670/mikromolbiomikromolbio2008-05-07T15:52:44+02:00Oligonucleotide_Array_Sequence_Analysis Transcription RNA_Stability Archaeal Genome Genetic Northern Halobacterium_salinarum Half-Life RNA Blotting Dactinomycin IFZ Messenger <span style="color:#555555;">Sonja <a href="http://www.bibsonomy.org/author/Hundt">Hundt</a> und Alexander <a href="http://www.bibsonomy.org/author/Zaigler">Zaigler</a> und Christian <a href="http://www.bibsonomy.org/author/Lange">Lange</a> und J&#246;rg <a href="http://www.bibsonomy.org/author/Soppa">Soppa</a> und Gabriele <a href="http://www.bibsonomy.org/author/Klug">Klug</a> </span><em>Journal of bacteriology</em><em>October2007. </em><em>PMID: 17644597 . </em>Wed May 07 15:52:44 CEST 2008Journal of bacteriologyOctoberPMID: 176445976936-44Global analysis of mRNA decay in Halobacterium salinarum NRC-1 at single-gene resolution using DNA microarrays1892007Oligonucleotide_Array_Sequence_Analysis Transcription RNA_Stability Archaeal Genome Genetic Northern Halobacterium_salinarum Half-Life RNA Blotting Dactinomycin IFZ Messenger RNA degradation is an important factor in the regulation of gene expression. It allows organisms to quickly respond to changing environmental conditions by adapting the expression of individual genes. The stability of individual mRNAs within an organism varies considerably, contributing to differential amounts of proteins expressed. In this study we used DNA microarrays to analyze mRNA degradation in exponentially growing cultures of the extremely halophilic euryarchaeon Halobacterium salinarum NRC-1 on a global level. We determined mRNA half-lives for 1,717 open reading frames, 620 of which are part of known or predicted operons. Under the tested conditions transcript stabilities ranged from 5 min to more than 18 min, with 79\% of the evaluated mRNAs showing half-lives between 8 and 12 min. The overall mean half-life was 10 min, which is considerably longer than the ones found in the other prokaryotes investigated thus far. As previously observed in Escherichia coli and Saccharomyces cerevisiae, we could not detect a significant correlation between transcript length and transcript stability, but there was a relationship between gene function and transcript stability. Genes that are known or predicted to be transcribed in operons exhibited similar mRNA half-lives. These results provide initial insights into mRNA turnover in a euryarchaeon. Moreover, our model organism, H. salinarum NRC-1, is one of just two archaea sequenced to date that are missing the core subunits of the archaeal exosome. This complex orthologous to the RNA degrading exosome of eukarya is found in all other archaeal genomes sequenced thus far.