1
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Zhang L, Lin J, Weng M, Wen Y, Zhang Y, Deng W. RPLP1, an NS4B-interacting protein, enhances production of CSFV through promoting translation of viral genome. Virulence 2022; 13:370-386. [PMID: 35129423 PMCID: PMC8824197 DOI: 10.1080/21505594.2022.2033500] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
Abstract
Classical swine fever virus (CSFV), the etiological agent of classical swine fever (CSF), causes serious financial losses to the pig industry. Using yeast two-hybrid screening, we have previously identified ribosomal protein RPLP1 as a potential binding partner of CSFV NS4B. In this study, the interaction between host RPLP1 and CSFV NS4B was further characterized by co-immunoprecipitation (co-IP), glutathione S-transferase (GST) pulldown, and confocal microscopy. In addition, lentivirus-mediated shRNA knockdown of RPLP1 drastically attenuated CSFV growth, while stable overexpression of RPLP1 markedly enhanced CSFV production. Moreover, cellular RPLP1 expression was found to be significantly up-regulated along with CSFV infection. Dual-luciferase reporter assay showed that depletion of RPLP1 had no effects on the activity of CSFV internal ribosome entry site (IRES). In the first life cycle of CSFV, further studies revealed that RPLP1 depletion did not influence the intracellular viral RNA abundance but diminished the intracellular and extracellular progeny virus titers as well as the viral E2 protein expression, which indicates that RPLP1 is crucial for CSFV genome translation. In summary, this study demonstrated that RPLP1 interacts with CSFV NS4B and enhances virus production via promoting translation of viral genome.
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Affiliation(s)
- Longxiang Zhang
- College of Veterinary Medicine, Northwest A&F University, Yangling, Shaanxi, China
| | - Jihui Lin
- School of Nursing, Southwest Medical University, Luzhou, Sichuan, China
| | - Maoyang Weng
- College of Veterinary Medicine, Northwest A&F University, Yangling, Shaanxi, China
| | - Ying Wen
- College of Veterinary Medicine, Northwest A&F University, Yangling, Shaanxi, China
| | - Yanming Zhang
- College of Veterinary Medicine, Northwest A&F University, Yangling, Shaanxi, China
| | - Wen Deng
- College of Veterinary Medicine, Northwest A&F University, Yangling, Shaanxi, China
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2
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Campos RK, Wijeratne HRS, Shah P, Garcia-Blanco MA, Bradrick SS. Ribosomal stalk proteins RPLP1 and RPLP2 promote biogenesis of flaviviral and cellular multi-pass transmembrane proteins. Nucleic Acids Res 2020; 48:9872-9885. [PMID: 32890404 PMCID: PMC7515724 DOI: 10.1093/nar/gkaa717] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2020] [Revised: 07/05/2020] [Accepted: 08/31/2020] [Indexed: 12/14/2022] Open
Abstract
The ribosomal stalk proteins, RPLP1 and RPLP2 (RPLP1/2), which form the ancient ribosomal stalk, were discovered decades ago but their functions remain mysterious. We had previously shown that RPLP1/2 are exquisitely required for replication of dengue virus (DENV) and other mosquito-borne flaviviruses. Here, we show that RPLP1/2 function to relieve ribosome pausing within the DENV envelope coding sequence, leading to enhanced protein stability. We evaluated viral and cellular translation in RPLP1/2-depleted cells using ribosome profiling and found that ribosomes pause in the sequence coding for the N-terminus of the envelope protein, immediately downstream of sequences encoding two adjacent transmembrane domains (TMDs). We also find that RPLP1/2 depletion impacts a ribosome density for a small subset of cellular mRNAs. Importantly, the polarity of ribosomes on mRNAs encoding multiple TMDs was disproportionately affected by RPLP1/2 knockdown, implying a role for RPLP1/2 in multi-pass transmembrane protein biogenesis. These analyses of viral and host RNAs converge to implicate RPLP1/2 as functionally important for ribosomes to elongate through ORFs encoding multiple TMDs. We suggest that the effect of RPLP1/2 at TMD associated pauses is mediated by improving the efficiency of co-translational folding and subsequent protein stability.
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Affiliation(s)
- Rafael K Campos
- Department of Biochemistry and Molecular Biology, University of Texas Medical Branch, Galveston, TX, USA.,Department of Molecular Genetics and Microbiology, Duke University, Durham, NC, USA
| | | | - Premal Shah
- Department of Genetics, Rutgers University, NJ, USA
| | - Mariano A Garcia-Blanco
- Department of Biochemistry and Molecular Biology, University of Texas Medical Branch, Galveston, TX, USA.,Programme of Emerging Infectious Diseases, Duke-NUS Medical School, Singapore
| | - Shelton S Bradrick
- Department of Biochemistry and Molecular Biology, University of Texas Medical Branch, Galveston, TX, USA
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3
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Mazón-Cabrera R, Vandormael P, Somers V. Antigenic Targets of Patient and Maternal Autoantibodies in Autism Spectrum Disorder. Front Immunol 2019; 10:1474. [PMID: 31379804 PMCID: PMC6659315 DOI: 10.3389/fimmu.2019.01474] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2019] [Accepted: 06/13/2019] [Indexed: 12/13/2022] Open
Abstract
Autism spectrum disorder (ASD) is a neurodevelopmental disorder whose behavioral symptoms become apparent in early childhood. The underlying pathophysiological mechanisms are only partially understood and the clinical manifestations are heterogeneous in nature, which poses a major challenge for diagnosis, prognosis and intervention. In the last years, an important role of a dysregulated immune system in ASD has emerged, but the mechanisms connecting this to a disruption of brain development are still largely unknown. Although ASD is not considered as a typical autoimmune disease, self-reactive antibodies or autoantibodies against a wide variety of targets have been found in a subset of ASD patients. In addition, autoantibodies reactive to fetal brain proteins have also been described in the prenatal stage of neurodevelopment, where they can be transferred from the mother to the fetus by transplacental transport. In this review, we give an extensive overview of the antibodies described in ASD according to their target antigens, their different origins, and timing of exposure during neurodevelopment.
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Affiliation(s)
| | | | - Veerle Somers
- Biomedical Research Institute, Faculty of Medicine and Life Science, Hasselt University, Diepenbeek, Belgium
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4
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Sekiba K, Otsuka M, Ohno M, Kishikawa T, Yamagami M, Suzuki T, Ishibashi R, Seimiya T, Tanaka E, Koike K. DHX9 regulates production of hepatitis B virus-derived circular RNA and viral protein levels. Oncotarget 2018; 9:20953-20964. [PMID: 29765512 PMCID: PMC5940377 DOI: 10.18632/oncotarget.25104] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2018] [Accepted: 03/24/2018] [Indexed: 12/22/2022] Open
Abstract
Hepatitis B virus (HBV) infection, which is a major health concern worldwide, can lead to liver cirrhosis and hepatocellular carcinoma. Although current nucleos(t)ide analogs efficiently inhibit viral reverse transcription and viral DNA load clinically, episomal viral covalently closed circular DNA (cccDNA) minichromosomes and transcripts from cccDNA continue to be expressed over the long term. We hypothesized that, under these conditions, viral transcripts may have biological functions involved in pathogenesis. Here, we show that the host protein DExH-box helicase 9 (DXH9) is associated with viral RNAs. We also show that viral-derived circular RNA is produced during HBV replication, and the amount is increased by knockdown of the DHX9 protein, which, in turn, results in decreased viral protein levels but does not affect the levels of HBV DNA. These phenomena were observed in the HBV-producing cell culture model and HBV mini-circle model mimicking HBV cccDNA, as well as in human primary hepatocytes infected with HBV. Based on these results, we conclude that, in HBV infection, the RNA binding factor DHX9 is a novel regulator of viral circular RNA and viral protein levels.
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Affiliation(s)
- Kazuma Sekiba
- Department of Gastroenterology, Graduate School of Medicine, The University of Tokyo, Tokyo 113-8655, Japan
| | - Motoyuki Otsuka
- Department of Gastroenterology, Graduate School of Medicine, The University of Tokyo, Tokyo 113-8655, Japan
| | - Motoko Ohno
- Department of Gastroenterology, Graduate School of Medicine, The University of Tokyo, Tokyo 113-8655, Japan
| | - Takahiro Kishikawa
- Department of Gastroenterology, Graduate School of Medicine, The University of Tokyo, Tokyo 113-8655, Japan
| | - Mari Yamagami
- Department of Gastroenterology, Graduate School of Medicine, The University of Tokyo, Tokyo 113-8655, Japan
| | - Tatsunori Suzuki
- Department of Gastroenterology, Graduate School of Medicine, The University of Tokyo, Tokyo 113-8655, Japan
| | - Rei Ishibashi
- Department of Gastroenterology, Graduate School of Medicine, The University of Tokyo, Tokyo 113-8655, Japan
| | - Takahiro Seimiya
- Department of Gastroenterology, Graduate School of Medicine, The University of Tokyo, Tokyo 113-8655, Japan
| | - Eri Tanaka
- Department of Gastroenterology, Graduate School of Medicine, The University of Tokyo, Tokyo 113-8655, Japan
| | - Kazuhiko Koike
- Department of Gastroenterology, Graduate School of Medicine, The University of Tokyo, Tokyo 113-8655, Japan
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5
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Baumann A, Lehmann R, Beckert A, Vilcinskas A, Franta Z. Selection and Evaluation of Tissue Specific Reference Genes in Lucilia sericata during an Immune Challenge. PLoS One 2015; 10:e0135093. [PMID: 26252388 PMCID: PMC4529112 DOI: 10.1371/journal.pone.0135093] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2015] [Accepted: 07/16/2015] [Indexed: 11/30/2022] Open
Abstract
The larvae of the common green bottle fly Lucilia sericata (Diptera: Calliphoridae) have been used for centuries to promote wound healing, but the molecular basis of their antimicrobial, debridement and healing functions remains largely unknown. The analysis of differential gene expression in specific larval tissues before and after immune challenge could be used to identify key molecular factors, but the most sensitive and reproducible method qRT-PCR requires validated reference genes. We therefore selected 10 candidate reference genes encoding products from different functional classes (18S rRNA, 28S rRNA, actin, β-tubulin, RPS3, RPLP0, EF1α, PKA, GAPDH and GST1). Two widely applied algorithms (GeNorm and Normfinder) were used to analyze reference gene candidates in different larval tissues associated with secretion, digestion, and antimicrobial activity (midgut, hindgut, salivary glands, crop and fat body). The Gram-negative bacterium Pseudomonas aeruginosa was then used to boost the larval immune system and the stability of reference gene expression was tested in comparison to three immune genes (lucimycin, defensin-1 and attacin-2), which target different pathogen classes. We observed no differential expression of the antifungal peptide lucimycin, whereas the representative targeting Gram-positive bacteria (defensin-1) was upregulated in salivary glands, crop, nerve ganglion and reached its maximum in fat body (up to 300-fold). The strongest upregulation in all immune challenged tissues (over 50,000-fold induction in the fat body) was monitored for attacin-2, the representative targeting Gram-negative bacteria. Here we identified and validated a set of reference genes that allows the accurate normalization of gene expression in specific tissues of L. sericata after immune challenge.
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Affiliation(s)
- Andre Baumann
- Department of Bioresources, Fraunhofer Institute for Molecular Biology and Applied Ecology, Giessen, Germany
| | - Rüdiger Lehmann
- Department of Bioresources, Fraunhofer Institute for Molecular Biology and Applied Ecology, Giessen, Germany
| | - Annika Beckert
- Department of Bioresources, Fraunhofer Institute for Molecular Biology and Applied Ecology, Giessen, Germany
| | - Andreas Vilcinskas
- Department of Bioresources, Fraunhofer Institute for Molecular Biology and Applied Ecology, Giessen, Germany
- Institute of Phytopathology and Applied Zoology, Justus-Liebig-University of Giessen, Giessen, Germany
| | - Zdeněk Franta
- Department of Bioresources, Fraunhofer Institute for Molecular Biology and Applied Ecology, Giessen, Germany
- * E-mail:
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6
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Ohmayer U, Gamalinda M, Sauert M, Ossowski J, Pöll G, Linnemann J, Hierlmeier T, Perez-Fernandez J, Kumcuoglu B, Leger-Silvestre I, Faubladier M, Griesenbeck J, Woolford J, Tschochner H, Milkereit P. Studies on the assembly characteristics of large subunit ribosomal proteins in S. cerevisae. PLoS One 2013; 8:e68412. [PMID: 23874617 PMCID: PMC3707915 DOI: 10.1371/journal.pone.0068412] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2013] [Accepted: 05/29/2013] [Indexed: 11/18/2022] Open
Abstract
During the assembly process of ribosomal subunits, their structural components, the ribosomal RNAs (rRNAs) and the ribosomal proteins (r-proteins) have to join together in a highly dynamic and defined manner to enable the efficient formation of functional ribosomes. In this work, the assembly of large ribosomal subunit (LSU) r-proteins from the eukaryote S. cerevisiae was systematically investigated. Groups of LSU r-proteins with specific assembly characteristics were detected by comparing the protein composition of affinity purified early, middle, late or mature LSU (precursor) particles by semi-quantitative mass spectrometry. The impact of yeast LSU r-proteins rpL25, rpL2, rpL43, and rpL21 on the composition of intermediate to late nuclear LSU precursors was analyzed in more detail. Effects of these proteins on the assembly states of other r-proteins and on the transient LSU precursor association of several ribosome biogenesis factors, including Nog2, Rsa4 and Nop53, are discussed.
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Affiliation(s)
- Uli Ohmayer
- Lehrstuhl für Biochemie III, Universität Regensburg, Regensburg, Germany
| | - Michael Gamalinda
- Department of Biological Sciences, Carnegie Mellon University, Pittsburgh, Pennsylvania, United States of America
| | - Martina Sauert
- Lehrstuhl für Biochemie III, Universität Regensburg, Regensburg, Germany
| | - Julius Ossowski
- Lehrstuhl für Biochemie III, Universität Regensburg, Regensburg, Germany
| | - Gisela Pöll
- Lehrstuhl für Biochemie III, Universität Regensburg, Regensburg, Germany
| | - Jan Linnemann
- Lehrstuhl für Biochemie III, Universität Regensburg, Regensburg, Germany
| | - Thomas Hierlmeier
- Lehrstuhl für Biochemie III, Universität Regensburg, Regensburg, Germany
| | | | - Beril Kumcuoglu
- Department of Biological Sciences, Carnegie Mellon University, Pittsburgh, Pennsylvania, United States of America
| | - Isabelle Leger-Silvestre
- Laboratoire de Biologie Moléculaire Eucaryote, UMR 5099, Universite Paul Sabatier, Toulouse, France
| | - Marlène Faubladier
- Laboratoire de Biologie Moléculaire Eucaryote, UMR 5099, Universite Paul Sabatier, Toulouse, France
| | | | - John Woolford
- Department of Biological Sciences, Carnegie Mellon University, Pittsburgh, Pennsylvania, United States of America
| | - Herbert Tschochner
- Lehrstuhl für Biochemie III, Universität Regensburg, Regensburg, Germany
| | - Philipp Milkereit
- Lehrstuhl für Biochemie III, Universität Regensburg, Regensburg, Germany
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7
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Baba K, Tumuraya K, Tanaka I, Yao M, Uchiumi T. Molecular dissection of the silkworm ribosomal stalk complex: the role of multiple copies of the stalk proteins. Nucleic Acids Res 2013; 41:3635-43. [PMID: 23376928 PMCID: PMC3616719 DOI: 10.1093/nar/gkt044] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
In animal ribosomes, two stalk proteins P1 and P2 form a heterodimer, and the two dimers, with the anchor protein P0, constitute a pentameric complex crucial for recruitment of translational GTPase factors to the ribosome. To investigate the functional contribution of each copy of the stalk proteins, we constructed P0 mutants, in which one of the two C-terminal helices, namely helix I (N-terminal side) or helix II (C-terminal side) were unable to bind the P1–P2 dimer. We also constructed ‘one-C-terminal domain (CTD) stalk dimers’, P1–P2ΔC and P1ΔC–P2, composed of intact P1/P2 monomer and a CTD-truncated partner. Through combinations of P0 and P1–P2 variants, various complexes were reconstituted and their function tested in eEF-2-dependent GTPase and eEF-1α/eEF-2-dependent polyphenylalanine synthesis assays in vitro. Double/single-CTD dimers bound to helix I showed higher activity than that bound to helix II. Despite low polypeptide synthetic activity by a single one-CTD dimer, its binding to both helices considerably increased activity, suggesting that two stalk dimers cooperate, particularly in polypeptide synthesis. This promotion of activity by two stalk dimers was lost upon mutation of the conserved YPT sequence connecting the two helices of P0, suggesting a role for this sequence in cooperativity of two stalk dimers.
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Affiliation(s)
- Kentaro Baba
- Department of Biology, Faculty of Science, Niigata University, Nishi-ku, Ikarashi-2, Niigata 950-2181, Japan
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8
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Comparative proteomic and phosphoproteomic analysis of the silkworm (Bombyx mori) posterior silk gland under high temperature treatment. Mol Biol Rep 2012; 39:8447-56. [PMID: 22707192 DOI: 10.1007/s11033-012-1698-5] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2012] [Accepted: 06/06/2012] [Indexed: 10/28/2022]
Abstract
The proteins from the posterior silk gland of silkworm hybrids and their parents reared under high temperatures were studied by using comparative proteomic and phosphoproteomic analysis. A total of 82.07, 6.17 and 11.76 % protein spots showed additivity, overdominance and underdominance patterns, respectively. Fifteen differentially expressed protein spots were identified by peptide mass fingerprinting. Among these, four spots, including sHSPs and prohibitin protein that were directly relevant to heat response, were identified. Eleven protein spots were found to play an important role in silk synthesis, and nine protein spots expressed phosphorylation states. According to Gene ontology and KEGG pathway analysis, these nine spots played an important role in stress-induced signal transduction. Expression of most silk synthesis-related proteins was reduced, whereas stress-responsive proteins increased with heat exposure time in three breeds. Furthermore, most proteins showed under- or overdominance in the hybrids compared to the parents. The results suggested that high temperature could alter the expression of proteins related to silk synthesis and heat response in silkworm. Moreover, differentially expressed proteins occurring in the hybrid and its parents may be the main explanation of the observed heterosis.
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9
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NMR insights into folding and self-association of Plasmodium falciparum P2. PLoS One 2012; 7:e36279. [PMID: 22567147 PMCID: PMC3342256 DOI: 10.1371/journal.pone.0036279] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2011] [Accepted: 04/04/2012] [Indexed: 11/19/2022] Open
Abstract
The eukaryotic 60S-ribosomal stalk is composed of acidic ribosomal proteins (P1 and P2) and neutral protein P0, which are thought to be associated as a pentameric structure, [2P1, 2P2, P0]. Plasmodium falciparum P2 (PfP2) appears to play additional non-ribosomal functions associated with its tendency for homo-oligomerization. Recombinant bacterially expressed PfP2 protein also undergoes self-association, as shown by SDS-PAGE analysis and light scattering studies. Secondary structure prediction algorithms predict the native PfP2 protein to be largely helical and this is corroborated by circular dichroism investigation. The 1H-15N HSQC spectrum of native P2 showed only 43 cross peaks compared to the expected 138. The observed peaks were found to belong to the C-terminal region, suggesting that this segment is flexible and solvent exposed. In 9 M urea denaturing conditions the chain exhibited mostly non-native β structural propensity. 15N Relaxation data for the denatured state indicated substantial variation in ms-µs time scale motion along the chain. Average area buried upon folding (AABUF) calculations on the monomer enabled identification of hydrophobic patches along the sequence. Interestingly, the segments of slower motion in the denatured state coincided with these hydrophobic patches, suggesting that in the denatured state the monomeric chain undergoes transient hydrophobic collapse. The implications of these results for the folding mechanism and self-association of PfP2 are discussed.
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10
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Tan SC, Carr CA, Yeoh KK, Schofield CJ, Davies KE, Clarke K. Identification of valid housekeeping genes for quantitative RT-PCR analysis of cardiosphere-derived cells preconditioned under hypoxia or with prolyl-4-hydroxylase inhibitors. Mol Biol Rep 2012; 39:4857-67. [PMID: 22065248 PMCID: PMC3294216 DOI: 10.1007/s11033-011-1281-5] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2011] [Accepted: 10/24/2011] [Indexed: 12/21/2022]
Abstract
Infarction irreversibly damages the heart, with formation of an akinetic scar that may lead to heart failure. Endogenous cardiac stem cells (CSCs) are a promising candidate cell source for restoring lost tissue and thereby preventing heart failure. CSCs may be isolated in vitro, via the formation of cardiospheres, to give cardiosphere-derived cells (CDCs). Although qRT-PCR analyses of CDCs have been performed, no justification for the selection of the housekeeping gene has been published. Here, we evaluated the most suitable housekeeping gene for RNA expression analysis in CDCs cultured under normoxia, hypoxia or with prolyl-4-hydroxylase inhibitors (PHDIs), from both neonatal and adult rats, to determine the effects of ageing and different culture conditions on the stability of the housekeeping gene for CDCs. Six candidate housekeeping genes, [glyceraldehyde-3-phosphate dehydrogenase (GAPDH), beta-actin (Actb), hypoxanthine phosphoribosyltransferase 1 (HPRT-1), beta-2-microtubulin (β2M), 60S acidic ribosomal protein large P1 (RPLP-1) and TATA box binding protein (Tbp)] were evaluated in this study. Analysis using geNorm and NormFinder revealed that GAPDH was the most constant housekeeping gene among all genes tested under normoxia for both neonatal and adult CDCs, whereas Actb was the most stable housekeeping gene under hypoxia. For the PHDI-treated CDCs, overall, GADPH, Actb and β2M were more consistently expressed, whereas HPRT-1, RPLP-1 and Tbp showed unstable expression. The ranking for β2M, HPRT-1 and RPLP-1 stability was different for neonatal and adult cells, indicating that expression of these genes was age-dependent. Lastly, independent of age or culture conditions, Tbp was the least stable housekeeping gene. In conclusion, a combination of Actb and GADPH gave the most reliable normalization for comparative analyses of gene transcription in neonatal and adult rat CDCs preconditioned by hypoxia or PHDIs.
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MESH Headings
- Animals
- Animals, Newborn
- Blotting, Western
- Cell Hypoxia/drug effects
- Cell Hypoxia/genetics
- DNA Primers/metabolism
- DNA, Complementary/genetics
- Enzyme Inhibitors/pharmacology
- Gene Expression Profiling
- Gene Expression Regulation/drug effects
- Genes, Essential/genetics
- Hypoxia-Inducible Factor 1, alpha Subunit/metabolism
- Myocardium/cytology
- Procollagen-Proline Dioxygenase/antagonists & inhibitors
- Procollagen-Proline Dioxygenase/metabolism
- RNA, Messenger/genetics
- RNA, Messenger/metabolism
- Rats
- Rats, Sprague-Dawley
- Reference Standards
- Reproducibility of Results
- Reverse Transcriptase Polymerase Chain Reaction/methods
- Reverse Transcriptase Polymerase Chain Reaction/standards
- Software
- Spheroids, Cellular/cytology
- Spheroids, Cellular/drug effects
- Spheroids, Cellular/metabolism
- Stem Cells/cytology
- Stem Cells/drug effects
- Stem Cells/enzymology
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Affiliation(s)
- Suat Cheng Tan
- Cardiac Metabolism Research Group, Department of Physiology, Anatomy & Genetics, University of Oxford, Sherrington Building, Parks Road, Oxford, OX1 3PT UK
| | - Carolyn A. Carr
- Cardiac Metabolism Research Group, Department of Physiology, Anatomy & Genetics, University of Oxford, Sherrington Building, Parks Road, Oxford, OX1 3PT UK
| | - Kar Kheng Yeoh
- Department of Chemistry, University of Oxford, Chemistry Research Laboratory, Mansfield Road, Oxford, OX1 3TA UK
| | - Christopher J. Schofield
- Department of Chemistry, University of Oxford, Chemistry Research Laboratory, Mansfield Road, Oxford, OX1 3TA UK
| | - Kay E. Davies
- Cardiac Metabolism Research Group, Department of Physiology, Anatomy & Genetics, University of Oxford, Sherrington Building, Parks Road, Oxford, OX1 3PT UK
| | - Kieran Clarke
- Cardiac Metabolism Research Group, Department of Physiology, Anatomy & Genetics, University of Oxford, Sherrington Building, Parks Road, Oxford, OX1 3PT UK
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11
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Casadei L, Vallorani L, Gioacchini AM, Guescini M, Burattini S, D'Emilio A, Biagiotti L, Falcieri E, Stocchi V. Proteomics-based investigation in C2C12 myoblast differentiation. Eur J Histochem 2012; 53:e31. [PMID: 22073363 PMCID: PMC3167332 DOI: 10.4081/ejh.2009.e31] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/02/2009] [Indexed: 11/23/2022] Open
Abstract
Skeletal muscle cell differentiation is a multistage process extensively studied over the years. Even if great improvements have been achieved in defining biological process underlying myogenesis, many molecular mechanisms need still to be clarified. To further highlight this process, we studied cells at undifferentiated, intermediate and highly differentiated stages, and we analyzed, for each condition, morphological and proteomic changes. We also identified the proteins that showed statistical significant changes by a ESI-Q-TOF mass spectrometer. This work provides further evidence of the involvement of particular proteins in skeletal muscle development. Furthermore, the high level of expression of many heat shock proteins, suggests a relationship between differentiation and cellular stress. Intriguingly, the discovery of myogenesis-correlated proteins, known to play a role in apoptosis, suggests a link between differentiation and this type of cell death.
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Affiliation(s)
- L Casadei
- Dipartimento di Scienze Biomolecolari, Università degli Studi di Urbino "Carlo Bo", Italy
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12
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Archaeal ribosomal stalk protein interacts with translation factors in a nucleotide-independent manner via its conserved C terminus. Proc Natl Acad Sci U S A 2012; 109:3748-53. [PMID: 22355137 DOI: 10.1073/pnas.1112934109] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Protein synthesis on the ribosome requires translational GTPase factors to bind to the ribosome in the GTP-bound form, take individual actions that are coupled with GTP hydrolysis, and dissociate, usually in the GDP-bound form. The multiple copies of the flexible ribosomal stalk protein play an important role in these processes. Using biochemical approaches and the stalk protein from a hyperthermophilic archaeon, Pyrococcus horikoshii, we here provide evidence that the conserved C terminus of the stalk protein aP1 binds directly to domain I of the elongation factor aEF-2, irrespective of whether aEF-2 is bound to GTP or GDP. Site-directed mutagenesis revealed that four hydrophobic amino acids at the C terminus of aP1, Leu-100, 103, 106, and Phe-107, are crucial for the direct binding. P1 was also found to bind to the initiation factor aIF5B, as well as aEF-1α, but not aIF2γ, via its C terminus. Moreover, analytical ultracentrifugation and gel mobility shift analyses showed that a heptameric complex of aP1 and aP0, aP0(aP1)(2)(aP1)(2)(aP1)(2), can bind multiple aEF-2 molecules simultaneously, which suggests that individual copies of the stalk protein are accessible to the factor. The functional significance of the C terminus of the stalk protein was also shown using the eukaryotic proteins P1/P2 and P0. It is likely that the conserved C terminus of the stalk proteins of archaea and eukaryotes can bind to translation factors both before and after GTP hydrolysis. This consistent binding ability of the stalk protein may contribute to maintaining high concentrations of translation factors around the ribosome, thus promoting translational efficiency.
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13
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Knubel CP, Martínez FF, Acosta Rodríguez EV, Altamirano A, Rivarola HW, Diaz Luján C, Fretes RE, Cervi L, Motrán CC. 3-Hydroxy kynurenine treatment controls T. cruzi replication and the inflammatory pathology preventing the clinical symptoms of chronic Chagas disease. PLoS One 2011; 6:e26550. [PMID: 22028903 PMCID: PMC3197528 DOI: 10.1371/journal.pone.0026550] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2011] [Accepted: 09/28/2011] [Indexed: 01/05/2023] Open
Abstract
Background 3-Hydroxy Kynurenine (3-HK) administration during the acute phase of Trypanosoma. cruzi infection decreases the parasitemia of lethally infected mice and improves their survival. However, due to the fact that the treatment with 3-HK is unable to eradicate the parasite, together with the known proapoptotic and immunoregulatory properties of 3-HK and their downstream catabolites, it is possible that the 3-HK treatment is effective during the acute phase of the infection by controlling the parasite replication, but at the same time suppressed the protective T cell response before pathogen clearance worsening the chronic phase of the infection. Therefore, in the present study, we investigated the effect of 3-HK treatment on the development of chronic Chagas’ disease. Principal Findings In the present study, we treated mice infected with T. cruzi with 3-HK at day five post infection during 5 consecutive days and investigated the effect of this treatment on the development of chronic Chagas disease. Cardiac functional (electrocardiogram) and histopathological studies were done at 60 dpi. 3-HK treatment markedly reduced the incidence and the severity of the electrocardiogram alterations and the inflammatory infiltrates and fibrosis in heart and skeletal muscle. 3-HK treatment modulated the immune response at the acute phase of the infection impairing the Th1- and Th2-type specific response and inducing TGF-β-secreting cells promoting the emergence of regulatory T cells and long-term specific IFN-γ secreting cells. 3-HK in vitro induced regulatory phenotype in T cells from T. cruzi acutely infected mice. Conclusions Our results show that the early 3-HK treatment was effective in reducing the cardiac lesions as well as altering the pattern of the immune response in experimental Chagas’ disease. Thus, we propose 3-HK as a novel therapeutic treatment able to control both the parasite replication and the inflammatory response.
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Affiliation(s)
- Carolina P. Knubel
- Departamento de Bioquímica Clínica, Facultad de Ciencias Químicas, Centro de Investigaciones en Bioquímica Clínica e Inmunología (CIBICI-CONICET), Universidad Nacional de Córdoba, Ciudad Universitaria, Córdoba, Argentina
| | - Fernando F. Martínez
- Departamento de Bioquímica Clínica, Facultad de Ciencias Químicas, Centro de Investigaciones en Bioquímica Clínica e Inmunología (CIBICI-CONICET), Universidad Nacional de Córdoba, Ciudad Universitaria, Córdoba, Argentina
| | - Eva V. Acosta Rodríguez
- Departamento de Bioquímica Clínica, Facultad de Ciencias Químicas, Centro de Investigaciones en Bioquímica Clínica e Inmunología (CIBICI-CONICET), Universidad Nacional de Córdoba, Ciudad Universitaria, Córdoba, Argentina
| | - Andrés Altamirano
- Departamento de Bioquímica Clínica, Facultad de Ciencias Químicas, Centro de Investigaciones en Bioquímica Clínica e Inmunología (CIBICI-CONICET), Universidad Nacional de Córdoba, Ciudad Universitaria, Córdoba, Argentina
| | - Héctor W. Rivarola
- Cátedra de Física Biomédica, Facultad de Ciencias Médicas, Universidad Nacional de Córdoba, Santa Rosa, Córdoba, Argentina
| | - Cintia Diaz Luján
- Facultad de Medicina, Instituto de Biología Celular, Universidad Nacional de Córdoba, Córdoba, Argentina
| | - Ricardo E. Fretes
- Facultad de Medicina, Instituto de Biología Celular, Universidad Nacional de Córdoba, Córdoba, Argentina
| | - Laura Cervi
- Departamento de Bioquímica Clínica, Facultad de Ciencias Químicas, Centro de Investigaciones en Bioquímica Clínica e Inmunología (CIBICI-CONICET), Universidad Nacional de Córdoba, Ciudad Universitaria, Córdoba, Argentina
| | - Claudia C. Motrán
- Departamento de Bioquímica Clínica, Facultad de Ciencias Químicas, Centro de Investigaciones en Bioquímica Clínica e Inmunología (CIBICI-CONICET), Universidad Nacional de Córdoba, Ciudad Universitaria, Córdoba, Argentina
- * E-mail:
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Cloning and characterization of the acidic ribosomal protein P2 of Cryptosporidium parvum, a new 17-kilodalton antigen. CLINICAL AND VACCINE IMMUNOLOGY : CVI 2010; 17:954-65. [PMID: 20410328 DOI: 10.1128/cvi.00073-10] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Cryptosporidium infection is commonly observed among children and immunocompromised individuals in developing countries, but large-scale outbreaks of disease among adults have not been reported. In contrast, outbreaks of cryptosporidiosis in the United States and Canada are increasingly common among patients of all ages. Thus, it seems likely that residents of regions where Cryptosporidium is highly endemic acquire some level of immunity, while residents of the developed world do not. A new immunodominant Cryptosporidium parvum antigen in the 15- to 17-kDa size range was identified as the Cryptosporidium parvum 60S acidic ribosomal protein P2 (CpP2). We developed a recombinant protein-based enzyme-linked immunosorbent assay for serologic population surveillance for antibodies that was 89% sensitive and 92% specific relative to the results of the large-format Western blot assay. The human IgG response is directed almost exclusively toward the highly conserved, carboxy-terminal 15 amino acids of the protein. Although IgG antibody cross-reactivity was documented with sera from patients with acute babesiosis, the development of an anti-CpP2 antibody response in our Peru study population correlated better with Cryptosporidium infection than with infection by any other parasitic protozoan. In Haiti, the prevalence of antibodies to CpP2 plateaus at 11 to 20 years of age. Because anti-CpP2 IgG antibodies were found only among residents of countries in the developing world where Cryptosporidium infection occurs early and often, we propose that this response may be a proxy for the intensity of infection and for acquired immunity.
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Naganuma T, Nomura N, Yao M, Mochizuki M, Uchiumi T, Tanaka I. Structural basis for translation factor recruitment to the eukaryotic/archaeal ribosomes. J Biol Chem 2009; 285:4747-56. [PMID: 20007716 DOI: 10.1074/jbc.m109.068098] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The archaeal ribosomal stalk complex has been shown to have an apparently conserved functional structure with eukaryotic pentameric stalk complex; it provides access to eukaryotic elongation factors at levels comparable to that of the eukaryotic stalk. The crystal structure of the archaeal heptameric (P0(P1)(2)(P1)(2)(P1)(2)) stalk complex shows that the rRNA anchor protein P0 consists of an N-terminal rRNA-anchoring domain followed by three separated spine helices on which three P1 dimers bind. Based on the structure, we have generated P0 mutants depleted of any binding site(s) for P1 dimer(s). Factor-dependent GTPase assay of such mutants suggested that the first P1 dimer has higher activity than the others. Furthermore, we constructed a model of the archaeal 50 S with stalk complex by superposing the rRNA-anchoring domain of P0 on the archaeal 50 S. This model indicates that the C termini of P1 dimers where translation factors bind are all localized to the region between the stalk base of the 50 S and P0 spine helices. Together with the mutational experiments we infer that the functional significance of multiple copies of P1 is in creating a factor pool within a limited space near the stalk base of the ribosome.
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Affiliation(s)
- Takao Naganuma
- Faculty of Advanced Life Science, Hokkaido University, Kita-ku, Kita-10, Nishi-8, Sapporo, 060-0810, Japan
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16
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Du YJ, Luo XY, Hao YZ, Zhang T, Hou WR. cDNA cloning and overexpression of acidic ribosomal phosphoprotein P1 gene (RPLP1) from the giant panda. Int J Biol Sci 2007; 3:428-33. [PMID: 18071584 PMCID: PMC2043164 DOI: 10.7150/ijbs.3.428] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2007] [Accepted: 10/18/2007] [Indexed: 01/23/2023] Open
Abstract
RPLP1 is one of acidic ribosomal phosphoproteins encoded by RPLP1 gene, which plays an important role in the elongation step of protein synthesis. The cDNA of RPLP1 was cloned successfully for the first time from the Giant Panda (Ailuropoda melanoleuca) using RT-PCR technology, which was also sequenced, analyzed preliminarily and expressed in E.coli. The cDNA fragment cloned is 449bp in size, containing an open reading frame of 344bp encoding 114 amino acids. Alignment analysis indicated that the nucleotide sequence and the deduced amino acid sequence are highly conserved to other five species studied, including Homo sapiens, Mus musculus, Rattus norvegicus, Bos Taurus and Sus scrofa. The homologies for nucleotide sequences of Giant Panda PPLP1 to that of these species are 92.4%, 89.8%, 89.0%, 91.3% and 87.5%, while the homologies for amino acid sequences are 96.5%, 94.7%, 95.6%, 96.5% and 88.6%. Topology prediction showed there are three Casein kinase II phosphorylation sites and two N-myristoylation sites in the RPLP1 protein of the Giant Panda (Ailuropoda melanoleuca). The RPLP1 gene was overexpressed in E. coli and the result indicated that RPLP1 fusion with the N-terminally His-tagged form gave rise to the accumulation of an expected 18kDa polypeptide, which was in accordance with the predicted protein and could also be used to purify the protein and study its function.
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Affiliation(s)
- Yu-Jie Du
- College of Life Science, China West Normal University, 44# Yuying Road, 637002, Nanchong, China
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17
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Nomura T, Nakano K, Maki Y, Naganuma T, Nakashima T, Tanaka I, Kimura M, Hachimori A, Uchiumi T. In vitro reconstitution of the GTPase-associated centre of the archaebacterial ribosome: the functional features observed in a hybrid form with Escherichia coli 50S subunits. Biochem J 2006; 396:565-71. [PMID: 16594895 PMCID: PMC1482815 DOI: 10.1042/bj20060038] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
We cloned the genes encoding the ribosomal proteins Ph (Pyrococcus horikoshii)-P0, Ph-L12 and Ph-L11, which constitute the GTPase-associated centre of the archaebacterium Pyrococcus horikoshii. These proteins are homologues of the eukaryotic P0, P1/P2 and eL12 proteins, and correspond to Escherichia coli L10, L7/L12 and L11 proteins respectively. The proteins and the truncation mutants of Ph-P0 were overexpressed in E. coli cells and used for in vitro assembly on to the conserved domain around position 1070 of 23S rRNA (E. coli numbering). Ph-L12 tightly associated as a homodimer and bound to the C-terminal half of Ph-P0. The Ph-P0.Ph-L12 complex and Ph-L11 bound to the 1070 rRNA fragments from the three biological kingdoms in the same manner as the equivalent proteins of eukaryotic and eubacterial ribosomes. The Ph-P0.Ph-L12 complex and Ph-L11 could replace L10.L7/L12 and L11 respectively, on the E. coli 50S subunit in vitro. The resultant hybrid ribosome was accessible for eukaryotic, as well as archaebacterial elongation factors, but not for prokaryotic elongation factors. The GTPase and polyphenylalanine-synthetic activity that is dependent on eukaryotic elongation factors was comparable with that of the hybrid ribosomes carrying the eukaryotic ribosomal proteins. The results suggest that the archaebacterial proteins, including the Ph-L12 homodimer, are functionally accessible to eukaryotic translation factors.
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Affiliation(s)
- Takaomi Nomura
- *Institute of High Polymer Research, Faculty of Textile Science and Technology, Shinshu University, Ueda 386-8567, Japan
| | - Kohji Nakano
- *Institute of High Polymer Research, Faculty of Textile Science and Technology, Shinshu University, Ueda 386-8567, Japan
| | - Yasushi Maki
- †Department of Biology, Faculty of Science, Niigata University, Niigata 950-2181, Japan
| | - Takao Naganuma
- †Department of Biology, Faculty of Science, Niigata University, Niigata 950-2181, Japan
| | - Takashi Nakashima
- †Department of Biology, Faculty of Science, Niigata University, Niigata 950-2181, Japan
| | - Isao Tanaka
- ‡Division of Biological Sciences, Graduate School of Science, Hokkaido University, Sapporo 060-0810, Japan
| | - Makoto Kimura
- §Department of Bioscience and Biotechnology, Faculty of Agriculture, Graduate School, Kyushu University, Fukuoka 812-8581, Japan
| | - Akira Hachimori
- *Institute of High Polymer Research, Faculty of Textile Science and Technology, Shinshu University, Ueda 386-8567, Japan
| | - Toshio Uchiumi
- †Department of Biology, Faculty of Science, Niigata University, Niigata 950-2181, Japan
- To whom correspondence should be addressed (email )
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Santos C, Rodríguez-Gabriel MA, Remacha M, Ballesta JPG. Ribosomal P0 protein domain involved in selectivity of antifungal sordarin derivatives. Antimicrob Agents Chemother 2004; 48:2930-6. [PMID: 15273103 PMCID: PMC478497 DOI: 10.1128/aac.48.8.2930-2936.2004] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The ribosomal stalk protein P0 is involved in the susceptibility to the antifungal sordarin derivatives, as reported for a number of Saccharomyces cerevisiae resistant mutants. Mammals and some lower eukaryotes are naturally resistant to these compounds. It is shown here that expression in S. cerevisiae of the ribosomal protein P0 from Homo sapiens and from other sordarin-resistant organisms results in a decrease in the sensitivity of the cells to an agent of this class. To further characterize the P0 region responsible for inducing sordarin resistance, a series of protein chimeras containing complementary regions of the human and yeast P0 proteins were constructed and expressed in yeast. The chimeras complement the absence of the native yeast P0 except in chimeras containing the human P0 carboxyl-terminal domain. Resistance to sordarins was found to be associated with the presence of an HsP0 amino acid sequence comprising P118 to F138, which unexpectedly led to higher resistance than the presence of the complete human P0. A comparison of the corresponding region in P0 from yeast and sordarin-insensitive organisms, followed by site-directed mutagenesis, indicates that residues in positions 119, 124, and 126 have an important role in determining resistance to sordarins. Moreover, since sordarins block the eukaryotic elongation factor 2 (EF2) function, the P0 region affecting sordarin susceptibility must correspond to EF2-interacting domains of the ribosomal stalk protein, which affects the drug-binding site in the elongation factor.
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Affiliation(s)
- C Santos
- Centro de Biología Molecular Severo Ochoa, CSIC and UAM, Canto Blanco, Madrid 28049, Spain
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19
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Rajeshwari K, Patel K, Nambeesan S, Mehta M, Sehgal A, Chakraborty T, Sharma S. The P domain of the P0 protein of Plasmodium falciparum protects against challenge with malaria parasites. Infect Immun 2004; 72:5515-21. [PMID: 15322057 PMCID: PMC517436 DOI: 10.1128/iai.72.9.5515-5521.2004] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Monoclonal antibodies (MAbs) specific for the P domain of the Plasmodium falciparum P0 phosphoriboprotein (PfP0) blocked the invasion of RBCs by P. falciparum. Vaccination with this P-domain peptide protected mice upon malaria parasite challenge. The absolute specificity of the MAbs and the PfP0 P peptide makes them potential protective malaria reagents.
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Affiliation(s)
- K Rajeshwari
- Department of Biological Sciences, Tata Institute of Fundamental Research, Homi Bhabha Rd., Mumbai 400 005, India
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20
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Mahler E, Hoebeke J, Levin MJ. Structural and functional complexity of the humoral response against the Trypanosoma cruzi ribosomal P2 beta protein in patients with chronic Chagas' heart disease. Clin Exp Immunol 2004; 136:527-34. [PMID: 15147356 PMCID: PMC1809055 DOI: 10.1111/j.1365-2249.2004.02480.x] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Abstract
High levels of antibodies against the C-terminus of the Trypanosoma cruzi TcP2 beta ribosomal protein, defined by the peptide EEEDDDMGFGLFD, named R13, have been measured in sera from patients with chronic Chagas' Heart Disease (cChHD). These antibodies also recognize an epitope on the second extracellular loop of the beta 1-adrenergic receptor, inducing a functional response on cardiomyocytes. The aim of this study was to gain novel insights into the structural basis of this cross-reactivity as well as to evaluate the origin of anti-M2- cholinergic receptor antibodies, which are also commonly found in cChHD patients. To address these questions we immunopurified anti-R13 antibodies and studied the structural requirements of epitope recognition. Results showed that the immunopurified antibodies recognized a conformation of R13 in which the third Glu residue was essential for binding, explaining their low affinity for the mammalian homologue (peptide H13: EESDDDMGFGLFD). Alanine mutation scanning showed individual variations in epitope recognition in each of the studied patients. The importance of a negatively charged residue at position 3 for the recognition of anti-R13 antibodies was further confirmed by competition experiments using a Ser3-phosphorylated H13 analogue, which had 10 times more affinity for the anti-R13 antibody than the native H13 peptide. Moreover, anti-R13 antibodies stimulated either the beta 1-adrenergic or the M2-cholinergic receptor, in strict agreement with the functional properties of the IgG fractions from which they derived, demonstrating that the same parasite antigen may generate antibody specificities with different functional properties. This may be a clue to explain the high variability of electrophysiological disturbances found in cChHD.
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Affiliation(s)
- E Mahler
- Departamento de Fisiología y Biología Molecular y Celular, Universidad de Buenos Aires, and Laboratorio de Biología Molecular de la Enfermedad de Chagas, Instituto de Investigaciones en Ingeniería Genética y Biología Molecular, Argentina
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21
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Odintsova TI, Müller EC, Ivanov AV, Egorov TA, Bienert R, Vladimirov SN, Kostka S, Otto A, Wittmann-Liebold B, Karpova GG. Characterization and analysis of posttranslational modifications of the human large cytoplasmic ribosomal subunit proteins by mass spectrometry and Edman sequencing. JOURNAL OF PROTEIN CHEMISTRY 2003; 22:249-58. [PMID: 12962325 DOI: 10.1023/a:1025068419698] [Citation(s) in RCA: 60] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
The 60S ribosomal proteins were isolated from ribosomes of human placenta and separated by reversed phase HPLC. The fractions obtained were subjected to trypsin and Glu-C digestion and analyzed by mass fingerprinting (MALDI-TOF), MS/MS (ESI), and Edman sequencing. Forty-six large subunit proteins were found, 22 of which showed masses in accordance with the SwissProt database (June 2002) masses (proteins L6, L7, L9, L13, L15, L17, L18, L21, L22, L24, L26, L27, L30, L32, L34, L35, L36, L37, L37A, L38, L39, L41). Eleven (proteins L7, L10A, L11, L12, L13A, L23, L23A, L27A, L28, L29, and P0) resulted in mass changes that are consistent with N-terminal loss of methionine, acetylation, internal methylation, or hydroxylation. A loss of methionine without acetylation was found for protein L8 and L17. For nine proteins (L3, L4, L5, L7A, L10, L14, L19, L31, and L40), the molecular masses could not be determined. Proteins P1 and protein L3-like were not identified by the methods applied.
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Affiliation(s)
- Tatyana I Odintsova
- Vavilov Institute of General Genetics, Russian Academy of Sciences, Moscow, Russian Federation
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22
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Shimizu T, Nakagaki M, Nishi Y, Kobayashi Y, Hachimori A, Uchiumi T. Interaction among silkworm ribosomal proteins P1, P2 and P0 required for functional protein binding to the GTPase-associated domain of 28S rRNA. Nucleic Acids Res 2002; 30:2620-7. [PMID: 12060678 PMCID: PMC117291 DOI: 10.1093/nar/gkf379] [Citation(s) in RCA: 62] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Acidic ribosomal phosphoproteins P0, P1 and P2 were isolated in soluble form from silkworm ribosomes and tested for their interactions with each other and with RNA fragments corresponding to the GTPase-associated domain of residues 1030-1127 (Escherichia coli numbering) in silkworm 28S rRNA in vitro. Mixing of P1 and P2 formed the P1-P2 heterodimer, as demonstrated by gel mobility shift and chemical crosslinking. This heterodimer, but neither P1 or P2 alone, tightly bound to P0 and formed a pentameric complex, presumably as P0(P1-P2)2, assumed from its molecular weight derived from sedimentation analysis. Complex formation strongly stimulated binding of P0 to the GTPase-associated RNA domain. The protein complex and eL12 (E.coli L11-type), which cross-bound to the E.coli equivalent RNA domain, were tested for their function by replacing with the E.coli counterparts L10.L7/L12 complex and L11 on the rRNA domain within the 50S subunits. Both P1 and P2, together with P0 and eL12, were required to activate ribosomes in polyphenylalanine synthesis dependent on eucaryotic elongation factors as well as eEF-2-dependent GTPase activity. The results suggest that formation of the P1-P2 heterodimer is required for subsequent formation of the P0(P1-P2)2 complex and its functional rRNA binding in silkworm ribosomes.
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Affiliation(s)
- Tomomi Shimizu
- Institute of High Polymer Research and Department of Applied Biological Science, Faculty of Textile Science and Technology, Shinshu University, Ueda 386-8567, Japan
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Hatzis P, Talianidis I. Regulatory mechanisms controlling human hepatocyte nuclear factor 4alpha gene expression. Mol Cell Biol 2001; 21:7320-30. [PMID: 11585914 PMCID: PMC99906 DOI: 10.1128/mcb.21.21.7320-7330.2001] [Citation(s) in RCA: 115] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Hepatocyte nuclear factor 4alpha (HNF-4alpha) (nuclear receptor 2A1) is an essential regulator of hepatocyte differentiation and function. Genetic and molecular evidence suggests that the tissue-restricted expression of HNF-4alpha is regulated mainly at the transcriptional level. As a step toward understanding the molecular mechanism involved in the transcriptional regulation of the human HNF-4alpha gene, we cloned and analyzed a 12.1-kb fragment of its upstream region. Major DNase I-hypersensitive sites were found at the proximal promoter, the first intron, and the more-upstream region comprising kb -6.5, -8.0, and -8.8. By the use of reporter constructs, we found that the proximal-promoter region was sufficient to drive high levels of hepatocyte-specific transcription in transient-transfection assays. DNase I footprint analysis and electrophoretic mobility shift experiments revealed binding sites for HNF-1alpha and -beta, Sp-1, GATA-6, and HNF-6. High levels of HNF-4alpha promoter activity were dependent on the synergism between either HNF-1alpha and HNF-6 or HNF-1beta and GATA-6, which implies that at least two alternative mechanisms may activate HNF-4alpha gene transcription. Chromatin immunoprecipitation experiments with human hepatoma cells showed stable association of HNF-1alpha, HNF-6, Sp-1, and COUP-TFII with the promoter. The last factor acts as a repressor via binding to a newly identified direct repeat 1 (DR-1) sequence of the human promoter, which is absent in the mouse homologue. We present evidence that this sequence is a bona fide retinoic acid response element and that HNF-4alpha expression is upregulated in vivo upon retinoic acid signaling.
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Affiliation(s)
- P Hatzis
- Institute of Molecular Biology and Biotechnology, Foundation for Research and Technology Hellas, 711 10 Herakleion, Crete, Greece
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24
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Briones C, Ballesta JP. Conformational changes induced in the Saccharomyces cerevisiae GTPase-associated rRNA by ribosomal stalk components and a translocation inhibitor. Nucleic Acids Res 2000; 28:4497-505. [PMID: 11071938 PMCID: PMC113874 DOI: 10.1093/nar/28.22.4497] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
The yeast ribosomal GTPase associated center is made of parts of the 26S rRNA domains II and VI, and a number of proteins including P0, P1alpha, P1beta, P2alpha, P2beta and L12. Mapping of the rRNA neighborhood of the proteins was performed by footprinting in ribosomes from yeast strains lacking different GTPase components. The absence of protein P0 dramatically increases the sensitivity of the defective ribosome to degradation hampering the RNA footprinting. In ribosomes lacking the P1/P2 complex, protection of a number of nucleotides is detected around positions 840, 880, 1100, 1220-1280 and 1350 in domain II as well as in several positions in the domain VI alpha-sarcin region. The protection pattern resembles the one reported for the interaction of elongation factors in bacterial systems. The results exclude a direct interaction of these proteins with the rRNA and are compatible with an increase in the ribosome affinity for EF-2 in the absence of the acidic P proteins. Interestingly, a sordarin derivative inhibitor of EF-2 causes an opposite effect, increasing the reactivity in positions protected by the absence of P1/P2. Similarly, a deficiency in protein L12 exposes nucleotides G1235, G1242, A1262, A1269, A1270 and A1272 to chemical modification, thus situating the protein binding site in the most conserved part of the 26S rRNA, equivalent to the bacterial protein L11 binding site.
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Affiliation(s)
- C Briones
- Centro de Biología Molecular 'Severo Ochoa', Consejo Superior de Investigaciones Científicas y Universidad Autónoma de Madrid, Canto Blanco, 28049 Madrid, Spain
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25
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Chatterjee S, Singh S, Sohoni R, Singh NJ, Vaidya A, Long C, Sharma S. Antibodies against ribosomal phosphoprotein P0 of Plasmodium falciparum protect mice against challenge with Plasmodium yoelii. Infect Immun 2000; 68:4312-8. [PMID: 10858250 PMCID: PMC101754 DOI: 10.1128/iai.68.7.4312-4318.2000] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Antibodies against the Plasmodium falciparum P0 ribosomal phosphoprotein (PfP0) have been detected exclusively but extensively in malaria-immune persons. Polyclonal rabbit and mice sera were raised against two recombinant polypeptides of P. falciparum P0 protein, PfP0N and PfP0C, covering amino acids 17 to 61 and the remaining amino acids 61 to 316, respectively. Sera against both these domains detected a 35-kDa protein from Plasmodium yoelii subsp. yoelii, a rodent malarial parasite, and stained the surface of merozoites in immunofluorescence assays. Total immunoglobulin G (IgG) purified from rabbit and mouse anti-PfP0 sera by ammonium sulfate and DEAE-cellulose chromatography was used for passive transfer experiments in mice. Mice passively immunized with both anti-PfP0N and anti-PfP0C showed distinctly lower levels of parasitemia than control mice. With immunizations on days -1, 0, 1, 3, and 5, about 50% of both sets of mice receiving anti-PfP0N and anti-PfP0C cleared the lethal 17XL strain of P. yoelii and revived by day 25. All the control mice died by day 10. By extending the immunization schedule, the survival period of the mice could be extended for every mouse that received anti-PfP0 IgG. These data demonstrate the cross-protection of the anti-PfP0 IgG and establish parasite P0 protein as a target for invasion-blocking antibodies.
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Affiliation(s)
- S Chatterjee
- Department of Biological Sciences, Tata Institute of Fundamental Research, Mumbai 400 005, India
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Hoyle GW, Li J, Finkelstein JB, Eisenberg T, Liu JY, Lasky JA, Athas G, Morris GF, Brody AR. Emphysematous lesions, inflammation, and fibrosis in the lungs of transgenic mice overexpressing platelet-derived growth factor. THE AMERICAN JOURNAL OF PATHOLOGY 1999; 154:1763-75. [PMID: 10362801 PMCID: PMC1866633 DOI: 10.1016/s0002-9440(10)65432-6] [Citation(s) in RCA: 105] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Because of its expression pattern and its potent effects on mesenchymal cells, platelet-derived growth factor (PDGF) has been implicated as an important factor in epithelial-mesenchymal cell interactions during normal lung development and in the pathogenesis of fibrotic lung disease. To further explore the role of PDGF in these processes, we have developed transgenic mice that express the PDGF-B gene from the lung-specific surfactant protein C (SPC) promoter. Adult SPC-PDGFB transgenic mice exhibited lung pathology characterized by enlarged airspaces, inflammation, and fibrosis. Emphysematous changes frequently occurred throughout the lung, but inflammation and fibrotic lesions were usually confined to focal areas. The severity of this phenotype varied significantly among individual mice within the same SPC-PDGFB transgenic lineage. A pathology similar to that observed in adult mice was noted in lungs from transgenic mice as young as 1 week of age. Neonatal transgenic mice exhibited enlarged saccules and thickened primary septa. Results of these studies indicated that overexpression of PDGF-B induced distinct abnormalities in the developing and adult lung and led to a complex phenotype that encompassed aspects of both emphysema and fibrotic lung disease.
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Affiliation(s)
- G W Hoyle
- Section of Pulmonary Diseases, Critical Care and Environmental Medicine, Department of Medicine, Tulane University, New Orleans, Louisiana, USA.
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27
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Mayer C, Appenzeller U, Seelbach H, Achatz G, Oberkofler H, Breitenbach M, Blaser K, Crameri R. Humoral and cell-mediated autoimmune reactions to human acidic ribosomal P2 protein in individuals sensitized to Aspergillus fumigatus P2 protein. J Exp Med 1999; 189:1507-12. [PMID: 10224291 PMCID: PMC2193053 DOI: 10.1084/jem.189.9.1507] [Citation(s) in RCA: 88] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
Abstract
A panel of cDNAs encoding allergenic proteins was isolated from an Aspergillus fumigatus cDNA library displayed on the surface of filamentous phage. Solid phase-immobilized serum immunoglobulin E (IgE) from A. fumigatus-allergic individuals was used to enrich phage displaying IgE-binding molecules. One of the cDNAs encoded a 11.1-kD protein that was identified as acidic ribosomal phosphoprotein type 2 (P2 protein). The allergen, formally termed rAsp f 8, shares >62% sequence identity and >84% sequence homology to corresponding eukaryotic P2 proteins, including human P2 protein. The sequences encoding human and fungal P2 protein were subcloned, expressed in Escherichia coli as His6-tagged fusion proteins, and purified by Ni2+-chelate affinity chromatography. Both recombinant P2 proteins were recognized by IgE antibodies from allergic individuals sensitized to the A. fumigatus P2 protein and elicited strong type 1-specific skin reactions in these individuals. Moreover, human and fungal P2 proteins induced proliferative responses in peripheral blood mononuclear cells of A. fumigatus- allergic subjects sensitized to the fungal P2 protein. These data provide strong evidence for in vitro and in vivo humoral and cell-mediated autoreactivity to human P2 protein in patients suffering from chronic A. fumigatus allergy.
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Affiliation(s)
- C Mayer
- Swiss Institute of Allergy and Asthma Research (SIAF), CH-7270 Davos, Switzerland
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28
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Huang WW, Garcia-Zepeda EA, Sauty A, Oettgen HC, Rothenberg ME, Luster AD. Molecular and biological characterization of the murine leukotriene B4 receptor expressed on eosinophils. J Exp Med 1998; 188:1063-74. [PMID: 9743525 PMCID: PMC2212531 DOI: 10.1084/jem.188.6.1063] [Citation(s) in RCA: 124] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022] Open
Abstract
The movement of leukocytes into tissues is regulated by the local production of chemical mediators collectively referred to as chemoattractants. Although chemoattractants constitute a diverse array of molecules, including proteins, peptides, and lipids, they all appear to signal leukocytes through a related family of seven transmembrane-spanning G protein-coupled receptors. The eosinophil is a potent proinflammatory cell that is attracted into tissues during allergic inflammation, parasitic infection, and certain malignancies. Since the molecular mechanisms controlling eosinophil recruitment are incompletely understood, we performed a degenerate polymerase chain reaction on cDNA isolated from murine eosinophils to identify novel chemoattractant receptors. We report the isolation of a cDNA that encodes a 351-amino acid glycoprotein that is 78% identical to a human gene that has been reported to be a purinoceptor (P2Y7) and a leukotriene B4 (LTB4) receptor (BLTR). Chinese hamster ovary (CHO) cells transfected with this cDNA specifically bound [3H]LTB4 with a dissociation constant of 0.6 +/- 0.1 nM. Furthermore, LTB4 induced a dose-dependent intracellular calcium flux in transfected CHO cells. In contrast, [35S]dATP did not specifically bind to these transfectants. This mRNA was expressed at high levels in interleukin 5-exposed eosinophils, elicited peritoneal macrophages and neutrophils, and to a lesser extent interferon gamma stimulated macrophages. Low levels of expression were detected in the lung, lymph node, and spleen of unchallenged mice. Western blot analysis detected the mBLTR protein in murine eosinophils and alveolar macrophages as well as human eosinophils. In addition, elevated levels of mBLTR mRNA were found in the lungs of mice in a murine model of allergic pulmonary inflammation in a time course consistent with the influx of eosinophils. Our findings indicate that this murine receptor is an LTB4 receptor that is highly expressed on activated leukocytes, including eosinophils, and may play an important role in mediating eosinophil recruitment into inflammatory foci.
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MESH Headings
- Amino Acid Sequence
- Animals
- CHO Cells
- Calcium/metabolism
- Cell Line
- Chemotactic Factors, Eosinophil/physiology
- Cloning, Molecular
- Cricetinae
- DNA, Complementary/analysis
- Disease Models, Animal
- Eosinophils/metabolism
- Eosinophils/pathology
- Female
- Humans
- Leukotriene B4/metabolism
- Macrophages, Alveolar/metabolism
- Mice
- Mice, Inbred Strains
- Mice, Transgenic
- Molecular Sequence Data
- Plasmids/genetics
- Protein Binding
- Protein Biosynthesis
- RNA, Messenger/biosynthesis
- Receptors, Leukotriene B4/biosynthesis
- Receptors, Leukotriene B4/blood
- Receptors, Leukotriene B4/chemistry
- Receptors, Leukotriene B4/genetics
- Receptors, Leukotriene B4/physiology
- Respiratory Hypersensitivity/immunology
- Respiratory Hypersensitivity/metabolism
- Respiratory Hypersensitivity/pathology
- Transfection
- Tumor Cells, Cultured
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Affiliation(s)
- W W Huang
- Infectious Disease Unit, AIDS Research Center, Department of Medicine, Massachusetts General Hospital, Charlestown 02129, USA
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29
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Matthews AN, Friend DS, Zimmermann N, Sarafi MN, Luster AD, Pearlman E, Wert SE, Rothenberg ME. Eotaxin is required for the baseline level of tissue eosinophils. Proc Natl Acad Sci U S A 1998; 95:6273-8. [PMID: 9600955 PMCID: PMC27654 DOI: 10.1073/pnas.95.11.6273] [Citation(s) in RCA: 210] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Eotaxin is an eosinophil-selective chemokine that is constitutively expressed in a variety of organs such as the intestine. Previous studies have demonstrated that the recruitment of eosinophils during inflammation is partially dependent on eotaxin, but the function of constitutive eotaxin during homeostasis has not been examined. To elucidate the biological role of this molecule, we now examine tissue levels of eosinophils in healthy states in wild-type and eotaxin-deficient mice. The lamina propria of the jejunum of wild-type mice is demonstrated to express eotaxin mRNA, but not mRNA for the related monocyte chemoattractant proteins. Wild-type mice contained readily detectable eosinophils in the lamina propria of the jejunum. In contrast, mice genetically deficient in eotaxin had a large selective reduction in the number of eosinophils residing in the jejunum. The reduction of tissue eosinophils was not limited to the jejunum, because a loss of thymic eosinophils was also observed in eotaxin-deficient mice. These studies demonstrate that eotaxin is a fundamental regulator of the physiological trafficking of eosinophils during healthy states. Because a variety of chemokines are constitutively expressed, their involvement in the baseline trafficking of leukocytes into nonhematopoietic tissue should now be considered.
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Affiliation(s)
- A N Matthews
- Division of Pulmonary Medicine, Allergy, and Clinical Immunology, Children's Hospital Medical Center, Cincinnati, OH 45229, USA
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30
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Borden KL, Campbelldwyer EJ, Carlile GW, Djavani M, Salvato MS. Two RING finger proteins, the oncoprotein PML and the arenavirus Z protein, colocalize with the nuclear fraction of the ribosomal P proteins. J Virol 1998; 72:3819-26. [PMID: 9557665 PMCID: PMC109605 DOI: 10.1128/jvi.72.5.3819-3826.1998] [Citation(s) in RCA: 89] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/1997] [Accepted: 01/28/1998] [Indexed: 02/07/2023] Open
Abstract
The promyelocytic leukemia (PML) protein forms nuclear bodies which are relocated to the cytoplasm by the RNA virus lymphocytic choriomeningitis virus (LCMV). The viral Z protein directly binds to PML and can relocate the nuclear bodies. Others have observed that LCMV virions may contain ribosomes; hence, we investigated the effects of infection on the distribution of ribosomal P proteins (P0, P1, and P2) with PML as a reference point. We demonstrate an association of PML bodies with P proteins by indirect immunofluorescence and coimmunoprecipitation experiments, providing the first evidence of nucleic acid-binding proteins associated with PML bodies. We show that unlike PML, the P proteins are not redistributed upon infection. Immunofluorescence and coimmunoprecipitation studies indicate that the viral Z protein binds the nuclear, but not the cytoplasmic, fraction of P0. The nuclear fraction of P0 has been associated with translationally coupled DNA excision repair and with nonspecific endonuclease activity; thus, P0 may be involved in nucleic acid processing activities necessary for LCMV replication. During the infection process, PML, P1, and P2 are downregulated but P0 remains unchanged. Further, P0 is present in virions while PML is not, indicating some selectivity in the assembly of LCMV.
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Affiliation(s)
- K L Borden
- Department of Biochemistry, Dalhousie University, Halifax, Nova Scotia, Canada.
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31
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Abstract
In order to analyse the specificity of human anti-ribosomal P protein antibodies, anti-ribosomal P protein antibodies were affinity-purified from the sera of lupus patients. Their binding capacity towards recombinant SmD protein and recombinant SmB/B' protein was evaluated by immunoblot and ELISA. Epitope mapping of SmD was performed by means of synthetic peptides. Anti-ribosomal P protein antibodies bound recombinant SmD (5/10) and SmB/B' (4/10) on immunoblot; 6/10 showed binding capacity to SmD on ELISA. Inhibition experiments using ELISA confirmed the specificity of this binding. Our data indicate the cross-reactivity of spontaneously developed anti-ribosomal P protein antibodies with the B/B' and D constituents of the Sm complex. The coexistence of anti-Sm and anti-ribosomal antibodies in lupus sera may therefore be due, at least in part, to the reactivity of a single autoantibody population.
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Affiliation(s)
- L Caponi
- Clinical Immunology Unit, Istituto di Patologia Medica, University of Pisa, Italy
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32
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Szick K, Springer M, Bailey-Serres J. Evolutionary analyses of the 12-kDa acidic ribosomal P-proteins reveal a distinct protein of higher plant ribosomes. Proc Natl Acad Sci U S A 1998; 95:2378-83. [PMID: 9482893 PMCID: PMC19351 DOI: 10.1073/pnas.95.5.2378] [Citation(s) in RCA: 51] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/1997] [Accepted: 12/17/1997] [Indexed: 02/06/2023] Open
Abstract
The P-protein complex of eukaryotic ribosomes forms a lateral stalk structure in the active site of the large ribosomal subunit and is thought to assist in the elongation phase of translation by stimulating GTPase activity of elongation factor-2 and removal of deacylated tRNA. The complex in animals, fungi, and protozoans is composed of the acidic phosphoproteins P0 (35 kDa), P1 (11-12 kDa), and P2 (11-12 kDa). Previously we demonstrated by protein purification and microsequencing that ribosomes of maize (Zea mays L.) contain P0, one type of P1, two types of P2, and a distinct P1/P2 type protein designated P3. Here we implemented distance matrices, maximum parsimony, and neighbor-joining analyses to assess the evolutionary relationships between the 12 kDa P-proteins of maize and representative eukaryotic species. The analyses identify P3, found to date only in mono- and dicotyledonous plants, as an evolutionarily distinct P-protein. Plants possess three distinct groups of 12 kDa P-proteins (P1, P2, and P3), whereas animals, fungi, and protozoans possess only two distinct groups (P1 and P2). These findings demonstrate that the P-protein complex has evolved into a highly divergent complex with respect to protein composition despite its critical position within the active site of the ribosome.
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Affiliation(s)
- K Szick
- Interdepartmental Graduate Program in Genetics, University of California, Riverside, CA 92521-0124, USA
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33
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Clarke RB, Howell A, Anderson E. Type I insulin-like growth factor receptor gene expression in normal human breast tissue treated with oestrogen and progesterone. Br J Cancer 1997; 75:251-7. [PMID: 9010034 PMCID: PMC2063278 DOI: 10.1038/bjc.1997.41] [Citation(s) in RCA: 71] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
The epithelial proliferation of normal human breast tissue xenografts implanted into athymic nude mice is significantly increased from basal levels by oestradiol (E2), but not progesterone (Pg) treatment at serum concentrations similar to those observed in the luteal phase of the human menstrual cycle. Type I IGF receptor (IGFR-I) mRNA and protein have been shown to be up-regulated by E2 in MCF-7 breast cancer cells in vitro in which IGF-I and E2 act synergistically to stimulate proliferation. We have investigated the expression of the IGFR-I mRNA in normal human breast xenografts treated with or without E2 or Pg alone and in combination. Northern analysis of 20 micrograms of RNA extracted from the breast xenograft samples showed no hybridization with 32P-labelled IGFR-I probe, although an 11-kb species of IGFR-I mRNA could be seen when 20 micrograms of RNA extracted from either MCF-7 breast cancer cells or human breast carcinomas was examined in this way. In order to analyse the expression of IGFR-I mRNA in breast xenografts, a quantitative reverse transcription-polymerase chain reaction (RT-PCR) was employed in which RNA loading, reverse transcription and PCR efficiencies were internally controlled. The data indicate that the IGFR-I mRNA is up-regulated by two to threefold compared with untreated levels by 7 and 14 days E2 treatment. In contrast, 7 or 14 days Pg treatment down-regulates the receptor mRNA to approximately half that of untreated levels, whereas combination E2 and Pg treatment produced a twofold increase in IGFR-I mRNA levels compared with untreated tissue. The results are consistent with the suggestion that E2 may act to stimulate proliferation indirectly via a paracrine mechanism involving IGFs in normal as well as malignant human breast epithelial cells.
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Affiliation(s)
- R B Clarke
- Clinical Research Department, Christie Hospital NHS Trust, Withington, Manchester, UK
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34
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Yacoub A, Kelley MR, Deutsch WA. Drosophila ribosomal protein PO contains apurinic/apyrimidinic endonuclease activity. Nucleic Acids Res 1996; 24:4298-303. [PMID: 8932386 PMCID: PMC146249 DOI: 10.1093/nar/24.21.4298] [Citation(s) in RCA: 64] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
Drosophila ribosomal protein PO was overexpressed in Escherichia coli to allow for its purification, biochemical characterization and to generate polyclonal antibodies for Western analysis. Biochemical tests were originally performed to see if overexpressed PO contained DNase activity similar to that recently reported for the apurinic/apyrimidinic (AP) lyase activity associated with Drosophila ribosomal protein S3. The overexpressed ribosomal protein was subsequently found to act on AP DNA, producing scissions that were in this case 5' of a baseless site instead of 3', as has been observed for S3. As a means of confirming that the source of AP endonuclease activity was in fact due to PO, glutathione S-transferase (GST) fusions containing a Factor Xa cleavage site between GST and PO were constructed, overexpressed in an E.coli strain defective for the major 5'-acting AP endonucleases and the fusions purified using glutathione-agarose affinity column chromatography. Isolated fractions containing purified GST-PO fusion proteins were subsequently found to have authentic AP endonuclease activity. Moreover, glutathione-agarose was able to deplete AP endonuclease activity from GST-PO fusion protein preparations, whereas the resin was ineffective in lowering DNA repair activity for PO that had been liberated from the fusion construct by Factor Xa cleavage. These results suggested that PO was a multifunctional protein with possible roles in DNA repair beyond its known participation in protein translation. In support of this notion, tests were performed that show that GST-PO, but not GST, was able to rescue an E.coli mutant lacking the major 5'-acting AP endonucleases from sensitivity to an alkylating agent. We furthermore show that GST-PO can be located in both the nucleus and ribosomes. Its nuclear location can be further traced to the nuclear matrix, thus placing PO in a subcellular location where it could act as a DNA repair protein. Other roles beyond DNA repair seem possible, however, since GST-PO also exhibited significant nuclease activity for both single- and double-stranded DNA.
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Affiliation(s)
- A Yacoub
- Pennington Biomedical Research Center, Baton Rouge, LA 70808, USA
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35
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Siomi MC, Zhang Y, Siomi H, Dreyfuss G. Specific sequences in the fragile X syndrome protein FMR1 and the FXR proteins mediate their binding to 60S ribosomal subunits and the interactions among them. Mol Cell Biol 1996; 16:3825-32. [PMID: 8668200 PMCID: PMC231379 DOI: 10.1128/mcb.16.7.3825] [Citation(s) in RCA: 199] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
Abstract
Fragile X syndrome, the most common form of hereditary mental retardation, usually results from lack of expression of the FMR1 gene. The FMR1 protein is a cytoplasmic RNA-binding protein. The RNA-binding activity of FMR1 is an essential feature of FMR1, as fragile X syndrome can also result from the expression of mutant FMR1 protein that is impaired in RNA binding. Recently, we described two novel cytoplasmic proteins, FXR1 and FXR2, which are both very similar in amino acid sequence to FMR1 and which also interact strongly with FMR1 and with each other. To understand the function of FMR1 and the FXR proteins, we carried out cell fractionation and sedimentation experiments with monoclonal antibodies to these proteins to characterize the complexes they form. Here, we report that the FMR1 and FXR proteins are associated with ribosomes, predominantly with 60S large ribosomal subunits. The FXR proteins are associated with 60S ribosomal subunits even in cells that lack FMR1 and that are derived from a fragile X syndrome patient, indicating that FMR1 is not required for this association. We delineated the regions of FMR1 that mediate its binding to 60S ribosomal subunits and the interactions among the FMR1-FXR family members. Both regions contain sequences predicted to have a high propensity to form coiled coil interactions, and the sequences are highly evolutionarily conserved in this protein family. The association of the FMR1, FXR1, and FXR2 proteins with ribosomes suggests they have functions in translation or mRNA stability.
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Affiliation(s)
- M C Siomi
- Howard Hughes Medical Institute, University of Pennsylvania School of Medicine, Philadelphia, 19104-6148, USA
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36
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Elson A, Leder P. Identification of a cytoplasmic, phorbol ester-inducible isoform of protein tyrosine phosphatase epsilon. Proc Natl Acad Sci U S A 1995; 92:12235-9. [PMID: 8618876 PMCID: PMC40331 DOI: 10.1073/pnas.92.26.12235] [Citation(s) in RCA: 69] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023] Open
Abstract
The protein-tyrosine phosphatase epsilon (PTP epsilon) is a transmembranal, receptor-type protein that possesses two phosphatase catalytic domains characteristic of transmembranal phosphatases. Here we demonstrate the existence of a nontransmembranal isoform of PTP epsilon, PTP epsilon-cytoplasmic. PTP epsilon-cytoplasmic and the transmembranal isoform of PTP epsilon have separate, nonoverlapping expression patterns. Further, the data clearly indicate that control of which of the two isoforms is to be expressed is initiated at the transcriptional level, suggesting that they have distinct physiological roles. PTP epsilon-cytoplasmic mRNA is the product of a delayed early response gene in NIH 3T3 fibroblasts, and its transcription is regulated through a pathway that requires protein kinase C. The human homologue of PTP epsilon-cytoplasmic has also been cloned and is strongly up-regulated in the early stages of phorbol 12-tetradecanoate 13-acetate-induced differentiation of HL-60 cells. Sequence analysis indicates and cellular fractionation experiments confirm that this isoform is a cytoplasmic molecule. PTP epsilon-cytoplasmic is therefore the initial example to our knowledge of a nontransmembranal protein-tyrosine phosphatase that contains two tandem of catalytic domains.
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Affiliation(s)
- A Elson
- Department of Genetics, Howard Hughes Medical Institute, Harvard Medical School, Boston, MA 02115, USA
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37
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Rothenberg ME, Luster AD, Leder P. Murine eotaxin: an eosinophil chemoattractant inducible in endothelial cells and in interleukin 4-induced tumor suppression. Proc Natl Acad Sci U S A 1995; 92:8960-4. [PMID: 7568052 PMCID: PMC41087 DOI: 10.1073/pnas.92.19.8960] [Citation(s) in RCA: 281] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
Guinea pig eotaxin is a recently described member of the Cys-Cys family of chemokines and is involved in a guinea pig model of asthma. To determine whether eotaxin is a distinctive member of this family and to understand its physiologic role, we have cloned the mouse eotaxin gene and determined its structure and aspects of its biologic function. The sequence relationship between the mouse and guinea pig genes indicates that eotaxin is indeed a distinct member of the chemokine family. Moreover, murine eotaxin maps to a region of mouse chromosome 11 that encodes other Cys-Cys chemokines. In addition, recombinant murine eotaxin protein has direct chemoattractant properties for eosinophils. The eotaxin gene is widely (but not ubiquitously) expressed in normal mice and is strongly induced in cultured endothelial cells in response to interferon gamma. Eotaxin is also induced locally in response to the transplantation of interleukin 4-secreting tumor cells, indicating that it likely contributes to the eosinophil recruitment and antitumor effect of interleukin 4. Such responses suggest that eotaxin may be involved in multiple inflammatory states.
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Affiliation(s)
- M E Rothenberg
- Howard Hughes Medical Institute, Department of Genetics, Harvard Medical School, Boston, MA 02115, USA
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38
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Soto M, Requena JM, Quijada L, Angel SO, Gomez LC, Guzman F, Patarroyo ME, Alonso C. During active viscerocutaneous leishmaniasis the anti-P2 humoral response is specifically triggered by the parasite P proteins. Clin Exp Immunol 1995; 100:246-52. [PMID: 7743663 PMCID: PMC1534337 DOI: 10.1111/j.1365-2249.1995.tb03661.x] [Citation(s) in RCA: 24] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
In this work we show that in the sera from dogs naturally infected with the protozoan parasite Leishmania infantum there are antibodies that react specifically against the parasite acidic ribosomal proteins LiP2a and LiP2b, and that each one of the Leishmania P proteins elicits a specific humoral immune response. Using synthetic peptides, the antigenic epitope of these proteins has been mapped in a single region located adjacent to the C-terminal domain highly conserved among the eukaryotic P proteins. The anti-P antibodies elicited during the Leishmania infection do not recognize the conserved C-terminal domain of the parasite P proteins, in contrast with the findings reported in Chagas' disease or systemic lupus erythematosus. The antigenic epitopes of the LiP2a and LiP2b are almost identical in amino acid sequence. No reactivity against Trypanosoma cruzi and human P proteins was found in sera from L. infantum-infected dogs.
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Affiliation(s)
- M Soto
- Centro de Biología Molecular Severo Ochoa, Universidad Autónoma de Madrid, Cantoblanco, Spain
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39
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Sinclair AJ, Palmero I, Peters G, Farrell PJ. EBNA-2 and EBNA-LP cooperate to cause G0 to G1 transition during immortalization of resting human B lymphocytes by Epstein-Barr virus. EMBO J 1994; 13:3321-8. [PMID: 8045261 PMCID: PMC395229 DOI: 10.1002/j.1460-2075.1994.tb06634.x] [Citation(s) in RCA: 197] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
Epstein-Barr virus (EBV) is unusual among DNA tumour viruses in that the virus particle is able to infect and immortalize resting cells with very high efficiency. Mutation of the viral genome has indicated that at least six viral genes (LMP-1 and EBNAs 1, 2, 3A, 3C and LP) are essential for immortalization. We demonstrate that the activation of a G1 cyclin, cyclin D2, is an early event following infection with EBV and that cyclin D2 activation is dependent on the expression of viral genes. The different levels of cyclin D2 transcripts in Burkitt's lymphoma cell lines expressing different subsets of EBV immortalizing genes suggest an involvement of EBNA-2 or EBNA-LP in cyclin D2 regulation. By exposing resting primary B cells to a purified preparation of the EBV surface glycoprotein gp340, we have been able to achieve efficient expression of plasmid DNAs introduced by electroporation. Vectors encoding two viral genes, EBNA-2 and EBNA-LP, are sufficient to activate the expression of cyclin D2 in this system. Thus, the progression of resting B lymphocytes into the G1 phase of the cell cycle can be reconstituted in the absence of virus by the cooperation of two of the six viral genes required for immortalization.
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Affiliation(s)
- A J Sinclair
- Ludwig Institute for Cancer Research, St. Mary's Hospital Medical School, London, UK
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40
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Vertebrate mRNAs with a 5'-terminal pyrimidine tract are candidates for translational repression in quiescent cells: characterization of the translational cis-regulatory element. Mol Cell Biol 1994. [PMID: 8196625 DOI: 10.1128/mcb.14.6.3822] [Citation(s) in RCA: 102] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The translation of mammalian ribosomal protein (rp) mRNAs is selectively repressed in nongrowing cells. This response is mediated through a regulatory element residing in the 5' untranslated region of these mRNAs and includes a 5' terminal oligopyrimidine tract (5' TOP). To further characterize the translational cis-regulatory element, we monitored the translational behavior of various endogenous and heterologous mRNAs or hybrid transcripts derived from transfected chimeric genes. The translational efficiency of these mRNAs was assessed in cells that either were growing normally or were growth arrested under various physiological conditions. Our experiments have yielded the following results: (i) the translation of mammalian rp mRNAs is properly regulated in amphibian cells, and likewise, amphibian rp mRNA is regulated in mammalian cells, indicating that all of the elements required for translation control of rp mRNAs are conserved among vertebrate classes; (ii) selective translational control is not confined to rp mRNAs, as mRNAs encoding the naturally occurring ubiquitin-rp fusion protein and elongation factor 1 alpha, which contain a 5' TOP, also conform this mode of regulation; (iii) rat rpP2 mRNA contains only five pyrimidines in its 5' TOP, yet this mRNA is translationally controlled in the same fashion as other rp mRNAs with a 5' TOP of eight or more pyrimidines; (iv) full manifestation of this mode of regulation seems to require both the 5' TOP and sequences immediately downstream; and (v) an intact translational regulatory element from rpL32 mRNA fails to exert its regulatory properties even when preceded by a single A residue.
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41
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Avni D, Shama S, Loreni F, Meyuhas O. Vertebrate mRNAs with a 5'-terminal pyrimidine tract are candidates for translational repression in quiescent cells: characterization of the translational cis-regulatory element. Mol Cell Biol 1994; 14:3822-33. [PMID: 8196625 PMCID: PMC358749 DOI: 10.1128/mcb.14.6.3822-3833.1994] [Citation(s) in RCA: 47] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023] Open
Abstract
The translation of mammalian ribosomal protein (rp) mRNAs is selectively repressed in nongrowing cells. This response is mediated through a regulatory element residing in the 5' untranslated region of these mRNAs and includes a 5' terminal oligopyrimidine tract (5' TOP). To further characterize the translational cis-regulatory element, we monitored the translational behavior of various endogenous and heterologous mRNAs or hybrid transcripts derived from transfected chimeric genes. The translational efficiency of these mRNAs was assessed in cells that either were growing normally or were growth arrested under various physiological conditions. Our experiments have yielded the following results: (i) the translation of mammalian rp mRNAs is properly regulated in amphibian cells, and likewise, amphibian rp mRNA is regulated in mammalian cells, indicating that all of the elements required for translation control of rp mRNAs are conserved among vertebrate classes; (ii) selective translational control is not confined to rp mRNAs, as mRNAs encoding the naturally occurring ubiquitin-rp fusion protein and elongation factor 1 alpha, which contain a 5' TOP, also conform this mode of regulation; (iii) rat rpP2 mRNA contains only five pyrimidines in its 5' TOP, yet this mRNA is translationally controlled in the same fashion as other rp mRNAs with a 5' TOP of eight or more pyrimidines; (iv) full manifestation of this mode of regulation seems to require both the 5' TOP and sequences immediately downstream; and (v) an intact translational regulatory element from rpL32 mRNA fails to exert its regulatory properties even when preceded by a single A residue.
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Affiliation(s)
- D Avni
- Department of Developmental Biochemistry, Hebrew University-Hadassah Medical School, Jerusalem, Israel
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42
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Liao D, Dennis PP. Molecular phylogenies based on ribosomal protein L11, L1, L10, and L12 sequences. J Mol Evol 1994; 38:405-19. [PMID: 8007008 DOI: 10.1007/bf00163157] [Citation(s) in RCA: 25] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Available sequences that correspond to the E. coli ribosomal proteins L11, L1, L10, and L12 from eubacteria, archaebacteria, and eukaryotes have been aligned. The alignments were analyzed qualitatively for shared structural features and for conservation of deletions or insertions. The alignments were further subjected to quantitative phylogenetic analysis, and the amino acid identity between selected pairs of sequences was calculated. In general, eubacteria, archaebacteria, and eukaryotes each form coherent and well-resolved nonoverlapping phylogenetic domains. The degree of diversity of the four proteins between the three groups is not uniform. For L11, the eubacterial and archaebacterial proteins are very similar whereas the eukaryotic L11 is clearly less similar. In contrast, in the case of the L12 proteins and to a lesser extent the L10 proteins, the archaebacterial and eukaryotic proteins are similar whereas the eubacterial proteins are different. The eukaryotic L1 equivalent protein has yet to be identified. If the root of the universal tree is near or within the eubacterial domain, our ribosomal protein-based phylogenies indicate that archaebacteria are monophyletic. The eukaryotic lineage appears to originate either near or within the archaebacterial domain.
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Affiliation(s)
- D Liao
- Canadian Institute for Advanced Research, University of British Columbia, Vancouver
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43
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Lobo CA, Kar SK, Ravindran B, Kabilan L, Sharma S. Novel proteins of Plasmodium falciparum identified by differential immunoscreening using immune and patient sera. Infect Immun 1994; 62:651-6. [PMID: 7507899 PMCID: PMC186153 DOI: 10.1128/iai.62.2.651-656.1994] [Citation(s) in RCA: 25] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023] Open
Abstract
A differential serological screen of a lambda gt11 cDNA expression library of Plasmodium falciparum was performed in an attempt to identify novel and putative host-protective antigens of the parasite. The screening was done with two categories of sera: (i) acute-phase sera obtained from smear-positive acutely infected P. falciparum patients from various regions in India and (ii) immune sera taken from healthy, permanent adult residents of P. falciparum-endemic rural districts of Orissa in eastern India. These adults had not suffered from any clinical malarial symptoms for at least the previous 3 years at the time of serum collection. Sixty-five clones obtained by screening the lambda gt11 library with two immune serum samples were analyzed extensively with a total of 70 acutely infected patient serum samples. Eight of these clones failed to react with any of the patient sera. Each of these eight clones, when tested individually with 92 serum samples from the immune group, reacted with a minimum of 43% of the samples from this category of sera. Thus, these eight epitopes may encode host-protective elements since they are not recognized by antibodies in the patient sera but react exclusively and extensively with the clinically immune set. Sequence analysis of two of these clones reveals that they are novel Plasmodium genes.
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Affiliation(s)
- C A Lobo
- Molecular Biology Unit, Tata Institute of Fundamental Research, Bombay, India
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44
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Venkatesh TV, Radding CM. Ribosomal protein S1 and NusA protein complexed to recombination protein beta of phage lambda. J Bacteriol 1993; 175:1844-6. [PMID: 8449891 PMCID: PMC203990 DOI: 10.1128/jb.175.6.1844-1846.1993] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023] Open
Abstract
The red genes of bacteriophage lambda specify two proteins, exonuclease and beta protein, which are essential for general recombination of lambda in recA cells. Earlier studies suggested that these proteins form an equimolar complex (C. M. Radding, J. Rosenweig, F. Richards, and E. Cassuto, J. Biol. Chem. 246:2510-2512, 1971). A more recent study indicated that beta protein forms a strong complex with an unknown polypeptide of 70 kDa (K. Muniyappa and C. M. Radding, J. Biol. Chem. 261:7472-7478, 1986). In the present study, in addition to the complex of beta and the 70-kDa protein, a new association of beta protein with a 65-kDa protein was observed. N-terminal sequencing identified these proteins as host-encoded ribosomal protein S1 and transcription terminator protein NusA.
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Affiliation(s)
- T V Venkatesh
- Department of Genetics, Yale University School of Medicine, New Haven, Connecticut 06510
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45
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Skeiky YA, Benson DR, Parsons M, Elkon KB, Reed SG. Cloning and expression of Trypanosoma cruzi ribosomal protein P0 and epitope analysis of anti-P0 autoantibodies in Chagas' disease patients. J Exp Med 1992; 176:201-11. [PMID: 1377223 PMCID: PMC2119278 DOI: 10.1084/jem.176.1.201] [Citation(s) in RCA: 57] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
Chagas' disease, caused by the intracellular protozoan parasite Trypanosoma cruzi, is a major cause of heart failure in endemic areas. Antigenic mimicry by T. cruzi antigens sharing epitopes with host macromolecules has been implicated in the pathogenesis which is thought to have a significant autoimmune component. We report herein on the cloning and characterization of a full-length cDNA from a T. cruzi expression library encoding a protein, TcP0, that is homologous to the human 38-kD ribosomal phosphoprotein HuP0. The T. cruzi P0 protein shows a clustering of residues that are evolutionarily conserved in higher eukaryotes. This includes an alanine- and glycine-rich region adjacent to a highly charged COOH terminus. This "hallmark" domain is the basis of the crossreactivity of the highly immunogenic eukaryotic P protein family. We found that T. cruzi-infected individuals have antibodies reacting with host (self) P proteins, as well as with recombinant TcP0. Deletion of the six carboxy-terminal amino acids abolished the reactivity of the T. cruzi infection sera with TcP0. This is similar to the specificity of anti-P autoantibodies described for a subset of patients with systemic lupus erythematosus (SLE) (Elkon, K., E. Bonfa, R. Llovet, W. Danho, H. Weissbach, and N. Brot. 1988. Proc. Natl. Acad. Sci. USA. 85:5186). These results suggest that T. cruzi P proteins may contribute to the development of autoreactive antibodies in Chagas' disease, and that the underlying mechanisms of anti-P autoantibody may be similar in Chagas' and SLE patients. This study represents the first definitive report of the cloning of a full-length T. cruzi antigen that mimics a characterized host homologue in structure, function, and shared antigenicity.
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Affiliation(s)
- Y A Skeiky
- Seattle Biomedical Research Institute, Washington 98109
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46
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Schijman AG, Levin MJ. Nucleotide sequence of a cDNA encoding a Trypanosoma cruzi acidic ribosomal PO protein: a novel C-terminal domain in T. cruzi ribosomal P proteins. Nucleic Acids Res 1992; 20:2894. [PMID: 1614881 PMCID: PMC336946 DOI: 10.1093/nar/20.11.2894] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Affiliation(s)
- A G Schijman
- Instituto de Investigaciones en Ingeniería Genética y Biología Molecular (INGEBI), Buenos Aires, Argentina
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47
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Selective translational control and nonspecific posttranscriptional regulation of ribosomal protein gene expression during development and regeneration of rat liver. Mol Cell Biol 1992. [PMID: 1373810 DOI: 10.1128/mcb.12.5.2203] [Citation(s) in RCA: 56] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Mammalian liver development is accompanied by a transition from rapid growth in the fetus to a quiescent state in the adult. However, extensive proliferation can be induced in the adult liver by partial hepatectomy. In this study, we examined the regulation of ribosomal protein (rp) gene expression in the developing and regenerating rat liver. Our results indicate that the translation of rp mRNAs is selectively repressed by about 70% upon development from fetal to adult life, as illustrated by the decrease in ribosomal loading. In addition, the relative abundance of these mRNAs, like that of several other, but not all, housekeeping mRNAs, declines during development through a posttranscriptional mechanism. When liver cells commence growth following partial hepatectomy, translation of rp mRNAs is resumed to near-maximal capacity, as judged by their very efficient recruitment into polysomes. The concomitant increase in the abundance rp mRNAs under these circumstances is achieved by a posttranscriptional mechanism. The apparent fluctuations in the translation efficiency of rp mRNAs are accompanied by parallel changes in the expression of the genes encoding the initiation factors eIF-4E and eIF-4A. Our results indicate that selective translational control of rp mRNAs in mammals is not confined to manipulated cells in culture but constitutes an important regulatory mechanism operating in vivo in the course of liver development and regeneration.
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48
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Vazquez MP, Schijman AG, Levin MJ. Nucleotide sequence of a cDNA encoding a Trypanosoma cruzi acidic ribosomal P1 type protein. Nucleic Acids Res 1992; 20:2599. [PMID: 1598221 PMCID: PMC312400 DOI: 10.1093/nar/20.10.2599] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Affiliation(s)
- M P Vazquez
- Instituto de Investigaciones en Ingeniería Genética y Biología Molecular (INGEBI), Buenos Aires, Argentina
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49
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Dalrymple BP, Peters JM. Identification of L10e/L12e ribosomal protein genes in Babesia bovis. Nucleic Acids Res 1992; 20:2376. [PMID: 1594456 PMCID: PMC312359 DOI: 10.1093/nar/20.9.2376] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Affiliation(s)
- B P Dalrymple
- CSIRO Division of Tropical Animal Production, Indooroopilly, Qld, Australia
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50
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Aloni R, Peleg D, Meyuhas O. Selective translational control and nonspecific posttranscriptional regulation of ribosomal protein gene expression during development and regeneration of rat liver. Mol Cell Biol 1992; 12:2203-12. [PMID: 1373810 PMCID: PMC364392 DOI: 10.1128/mcb.12.5.2203-2212.1992] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
Mammalian liver development is accompanied by a transition from rapid growth in the fetus to a quiescent state in the adult. However, extensive proliferation can be induced in the adult liver by partial hepatectomy. In this study, we examined the regulation of ribosomal protein (rp) gene expression in the developing and regenerating rat liver. Our results indicate that the translation of rp mRNAs is selectively repressed by about 70% upon development from fetal to adult life, as illustrated by the decrease in ribosomal loading. In addition, the relative abundance of these mRNAs, like that of several other, but not all, housekeeping mRNAs, declines during development through a posttranscriptional mechanism. When liver cells commence growth following partial hepatectomy, translation of rp mRNAs is resumed to near-maximal capacity, as judged by their very efficient recruitment into polysomes. The concomitant increase in the abundance rp mRNAs under these circumstances is achieved by a posttranscriptional mechanism. The apparent fluctuations in the translation efficiency of rp mRNAs are accompanied by parallel changes in the expression of the genes encoding the initiation factors eIF-4E and eIF-4A. Our results indicate that selective translational control of rp mRNAs in mammals is not confined to manipulated cells in culture but constitutes an important regulatory mechanism operating in vivo in the course of liver development and regeneration.
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Affiliation(s)
- R Aloni
- Department of Developmental Biochemistry, Hebrew University-Hadassah Medical School, Jerusalem, Israel
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