<i>Escherichia coli</i>
            CspA-family RNA chaperones are transcription antiterminators

Bae, Weonhye; Xia, Bing; Inouye, Masayori; Severinov, Konstantin

doi:10.1073/pnas.97.14.7784

Cited by 358 publications

(370 citation statements)

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“…That function could be regulation of mt gene expression during plant acclimation to cold, a process that only recently starts to be understood (32). It is for instance possible that, like CspA, the major cold-shock protein of E. coli, mRBP1 proteins function as mRNA chaperones to destabilize secondary structures in mt mRNAs (33,34). Such a function could be crucial for efficient mt transcription or translation at low temperatures.…”

Section: Origin Of the Mrbp Gene Family: Gr Rna-binding Proteins Regumentioning

confidence: 99%

A family of RRM-type RNA-binding proteins specific to plant mitochondria

Vermel

Guermann

Delage

et al. 2002

Proc. Natl. Acad. Sci. U.S.A.

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Expression of higher plant mitochondrial (mt) genes is regulated at the transcriptional, posttranscriptional, and translational levels, but the vast majority of the mtDNA and RNA-binding proteins involved remain to be identified. Plant mt single-stranded nucleic acid-binding proteins were purified by affinity chromatography, and corresponding genes have been identified. A majority of these proteins belong to a family of RNA-binding proteins characterized by the presence of an N-terminal RNA-recognition motif (RRM) sequence. They diverge in their C-terminal sequences, suggesting that they can be involved in different plant mt regulation processes. Mitochondrial localization of the proteins was confirmed both in vitro and in vivo and by immunolocalization. Binding experiments showed that several proteins have a preference for poly(U)-rich sequences. This mt protein family contains the ubiquitous RRM motif and has no known mt counterpart in non-plant species. Phylogenetic and functional analysis suggest a common ancestor with RNA-binding glycine-rich proteins (GRP), a family of developmentally regulated proteins of unknown function. As with several plant, cyanobacteria, and animal proteins that have similar structures, the expression of one of the Arabidopsis thaliana mt RNA-binding protein genes is induced by low temperatures.H igher plants require mitochondrial (mt) function for their survival, which depends on proper mtDNA maintenance and expression (1). At the structural level, the mtDNA of plants is relatively large, and in most species it is constantly reorganized by recombination between repeated sequences (2). Although large portions of mtDNA have been moved around during evolution, the plant mt genome evolves very slowly through nucleotide substitution; plant mt gene sequences have remained remarkably constant, suggesting the existence of very efficient DNA repair systems. On the other hand, the expression of plant mt genes is also complexly regulated, both at the transcriptional, posttranscriptional, and translational levels. For proper maturation of its transcripts, mitochondria puts to play complex processes of intron splicing, 5Ј and 3Ј RNA trimming, extensive RNA editing by C to U conversions, and regulation of transcript stability by secondary structures and polyadenylation (3, 4). Despite the importance of these mt processes in plant development, little is known about the factors involved, but at the core of the protein complexes must be DNA-binding proteins involved in mtDNA replication, recombination, repair and transcription, and RNA-binding proteins involved in posttranscriptional RNA maturation and translation. As a first step in the dissection of these complexes, we undertook to purify and identify nucleic acid-binding proteins from plant mitochondria. Most of the proteins identified are plant-specific, and many belong to a previously undescribed family of mt RNA-binding proteins (mRBP) characterized by the presence of an N-terminal RNA recognition motif (RRM). This family of plant mRBPs is ph...

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Section: Origin Of the Mrbp Gene Family: Gr Rna-binding Proteins Regumentioning

confidence: 99%

A family of RRM-type RNA-binding proteins specific to plant mitochondria

Vermel

Guermann

Delage

et al. 2002

Proc. Natl. Acad. Sci. U.S.A.

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“…by differential mRNA stability (Brandi et al, 1996). CspA acts as transcriptional antiterminator of certain genes that are upregulated in the cold (Bae et al, 2000) as well as an RNA chaperone, which prevents the formation of secondary structures in RNA, and thus ensures efficient translation of mRNA at low temperature . Four hours after a cold shock, the cold-adaptation phase is completed, and regular protein synthesis and growth are resumed.…”

Section: Introductionmentioning

confidence: 99%

Identification and regulation of cold-inducible factors of Bordetella bronchiseptica

et al. 2005

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The expression of bacterial cold-shock proteins (CSPs) is highly induced in response to cold shock, and some CSPs are essential for cells to resume growth at low temperature. Bordetella bronchiseptica encodes five CSPs (named CspA to CspE) with significant amino acid homology to CspA of Escherichia coli. In contrast to E. coli, the insertional knock-out of a single csp gene (cspB) strongly affected growth of B. bronchiseptica independent of temperature. In the case of three of the csp genes (cspA, cspB, cspC) more than one specific transcript could be detected. The net amount of cspA, cspB and cspC transcripts increased strongly after cold shock, while no such effect could be observed for cspD and cspE. The exposure to other stress conditions, including translation inhibitors, heat shock, osmotic stress and nutrient deprivation in the stationary phase, indicated that the csp genes are also responsive to these conditions. The coding regions of all of the cold-shock genes are preceded by a long non-translated upstream region (59-UTR). In the case of the cspB gene, a deletion of parts of this region led to a significant reduction of translation of the resulting truncated transcript, indicating a role of the 59-UTR in translational control. The cold-shock stimulon was investigated by 2D-PAGE and mass spectrometric characterization, leading to the identification of additional cold-inducible proteins (CIPs). Interestingly, two cold-shock genes (cspC and cspD) were found to be under the negative control of the BvgAS system, the main transcriptional regulator of Bordetella virulence genes. Moreover, a negative effect of slight overexpression of CspB, but not of the other CSPs, on the transcription of the adenylate cyclase toxin CyaA of Bordetella pertussis was observed, suggesting cross-talk between the CSP-mediated stress response stimulon and the Bordetella virulence regulon.

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“…RBD proteins are thought to have evolved a similar three-dimensional functional surface for nucleic acid binding through convergent evolution (Graumann and Marahiel, 1996) and may have replaced CSD proteins (Graumann and Marahiel, 1998). Bacterial CSP homologs show high homology to the well-characterized eukaryotic Y-box proteins (Wolffe, 1993;Bae et al, 2000), which contain an N-terminal CSD and C-terminal auxiliary domains that facilitate a broad range of in vivo functions such as RNA masking and transcriptional and translational regulation (Sommerville, 1999). Surprisingly, within the plant kingdom, only four proteins are documented to contain a CSD.…”

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confidence: 99%

“…Prokaryotic response to low temperature has been extensively studied in Escherichia coli and is accompanied by a spectacular accumulation of nucleic acidbinding CSPs (Graumann and Marahiel, 1998;Yamanaka et al, 1998;Bae et al, 2000). CspA, the most prominent of the nine-member E. coli CSP family, accumulates up to 10% of total proteins during cold stress (Jiang et al, 1997).…”

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confidence: 99%