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Larionova TD, Bastola S, Aksinina TE, Anufrieva KS, Wang J, Shender VO, Andreev DE, Kovalenko TF, Arapidi GP, Shnaider PV, Kazakova AN, Latyshev YA, Tatarskiy VV, Shtil AA, Moreau P, Giraud F, Li C, Wang Y, Rubtsova MP, Dontsova OA, Condro M, Ellingson BM, Shakhparonov MI, Kornblum HI, Nakano I, Pavlyukov MS. Alternative RNA splicing modulates ribosomal composition and determines the spatial phenotype of glioblastoma cells. Nat Cell Biol 2022; 24:1541-1557. [PMID: 36192632 PMCID: PMC10026424 DOI: 10.1038/s41556-022-00994-w] [Citation(s) in RCA: 21] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2021] [Accepted: 08/15/2022] [Indexed: 02/08/2023]
Abstract
Glioblastoma (GBM) is characterized by exceptionally high intratumoral heterogeneity. However, the molecular mechanisms underlying the origin of different GBM cell populations remain unclear. Here, we found that the compositions of ribosomes of GBM cells in the tumour core and edge differ due to alternative RNA splicing. The acidic pH in the core switches before messenger RNA splicing of the ribosomal gene RPL22L1 towards the RPL22L1b isoform. This allows cells to survive acidosis, increases stemness and correlates with worse patient outcome. Mechanistically, RPL22L1b promotes RNA splicing by interacting with lncMALAT1 in the nucleus and inducing its degradation. Contrarily, in the tumour edge region, RPL22L1a interacts with ribosomes in the cytoplasm and upregulates the translation of multiple messenger RNAs including TP53. We found that the RPL22L1 isoform switch is regulated by SRSF4 and identified a compound that inhibits this process and decreases tumour growth. These findings demonstrate how distinct GBM cell populations arise during tumour growth. Targeting this mechanism may decrease GBM heterogeneity and facilitate therapy.
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Affiliation(s)
- Tatyana D Larionova
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Moscow, Russian Federation
| | - Soniya Bastola
- Department of Bioengineering, University of California Los Angeles, Los Angeles, CA, USA
| | - Tatiana E Aksinina
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Moscow, Russian Federation
| | - Ksenia S Anufrieva
- Center for Precision Genome Editing and Genetic Technologies for Biomedicine, Federal Research and Clinical Center of Physical-Chemical Medicine, Federal Medical Biological Agency, Moscow, Russian Federation
- Federal Research and Clinical Center of Physical-Chemical Medicine, Federal Medical and Biological Agency, Moscow, Russian Federation
| | - Jia Wang
- Department of Neurosurgery, Centre of Brain Science, First Affiliated Hospital of Xi'an Jiaotong University, Xi'an, China
| | - Victoria O Shender
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Moscow, Russian Federation
- Center for Precision Genome Editing and Genetic Technologies for Biomedicine, Federal Research and Clinical Center of Physical-Chemical Medicine, Federal Medical Biological Agency, Moscow, Russian Federation
- Federal Research and Clinical Center of Physical-Chemical Medicine, Federal Medical and Biological Agency, Moscow, Russian Federation
| | - Dmitriy E Andreev
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Moscow, Russian Federation
- Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Moscow, Russian Federation
| | - Tatiana F Kovalenko
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Moscow, Russian Federation
| | - Georgij P Arapidi
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Moscow, Russian Federation
- Center for Precision Genome Editing and Genetic Technologies for Biomedicine, Federal Research and Clinical Center of Physical-Chemical Medicine, Federal Medical Biological Agency, Moscow, Russian Federation
- Federal Research and Clinical Center of Physical-Chemical Medicine, Federal Medical and Biological Agency, Moscow, Russian Federation
| | - Polina V Shnaider
- Center for Precision Genome Editing and Genetic Technologies for Biomedicine, Federal Research and Clinical Center of Physical-Chemical Medicine, Federal Medical Biological Agency, Moscow, Russian Federation
- Federal Research and Clinical Center of Physical-Chemical Medicine, Federal Medical and Biological Agency, Moscow, Russian Federation
| | - Anastasia N Kazakova
- Federal Research and Clinical Center of Physical-Chemical Medicine, Federal Medical and Biological Agency, Moscow, Russian Federation
| | - Yaroslav A Latyshev
- N.N. Burdenko National Medical Research Center of Neurosurgery, Ministry of Health of the Russian Federation, Moscow, Russian Federation
| | - Victor V Tatarskiy
- Institute of Gene Biology, Russian Academy of Sciences, Moscow, Russian Federation
| | - Alexander A Shtil
- Blokhin National Medical Research Center of Oncology, Moscow, Russian Federation
| | - Pascale Moreau
- Institute of Chemistry of Clermont-Ferrand, CNRS, Université Clermont Auvergne, Clermont-Ferrand, France
| | - Francis Giraud
- Institute of Chemistry of Clermont-Ferrand, CNRS, Université Clermont Auvergne, Clermont-Ferrand, France
| | - Chaoxi Li
- Department of Neurosurgery, School of Medicine and O'Neal Comprehensive Cancer Center, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Yichan Wang
- Department of Neurosurgery, Centre of Brain Science, First Affiliated Hospital of Xi'an Jiaotong University, Xi'an, China
| | - Maria P Rubtsova
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Moscow, Russian Federation
- Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Moscow, Russian Federation
| | - Olga A Dontsova
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Moscow, Russian Federation
- Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Moscow, Russian Federation
- Center of Life Sciences, Skolkovo Institute of Science and Technology, Moscow, Russian Federation
| | - Michael Condro
- Department of Bioengineering, University of California Los Angeles, Los Angeles, CA, USA
| | - Benjamin M Ellingson
- Brain Tumor Imaging Laboratory, Center for Computer Vision and Imaging Biomarkers, University of California Los Angeles, Los Angeles, CA, USA
- Department of Radiological Sciences, University of California Los Angeles, Los Angeles, CA, USA
- Department of Psychiatry, University of California Los Angeles, Los Angeles, CA, USA
- Department of Neurosurgery, University of California Los Angeles, Los Angeles, CA, USA
| | | | - Harley I Kornblum
- Intellectual and Developmental Disabilities Research Center, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, CA, USA
| | - Ichiro Nakano
- Department of Neurosurgery, Medical Institute of Hokuto, Hokkaido, Japan.
| | - Marat S Pavlyukov
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Moscow, Russian Federation.
- Centre for Genomic Regulation, Barcelona Institute of Science and Technology, Barcelona, Spain.
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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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Xu X, Qiu H, Shi F, Wang Z, Wang X, Jin L, Chi L, Zhang Q. The protein S-nitrosylation of splicing and translational machinery in vascular endothelial cells is susceptible to oxidative stress induced by oxidized low-density lipoprotein. J Proteomics 2019; 195:11-22. [PMID: 30630120 DOI: 10.1016/j.jprot.2019.01.001] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2018] [Revised: 12/18/2018] [Accepted: 01/05/2019] [Indexed: 12/24/2022]
Abstract
Oxidized low-density lipoprotein (ox-LDL) can impair endothelial function and lead to the atherosclerosis development. Protein S-nitrosylation is sensitive to cellular redox state and acts as a crucial regulator and executor of nitric oxide (NO) signaling pathways. Aberrant S-nitrosylation contributes to the pathogenesis of cardiovascular and cerebrovascular diseases. However, the effect of ox-LDL on S-nitrosylation and its significance for endothelial dysfunction have not been studied at proteome level. Herein, the combined quantitative analysis of proteome and S-nitrosoproteome was performed using an integrated biotin switch and iTRAQ labeling approach in EA.hy926 cell line derived from human umbilical vein endothelial cell (HUVEC) treated with ox-LDL. A total of 2204 S-nitrosylated (SNO) peptides of 1318 SNO-proteins were quantified. Notably, 352 SNO-peptides of 262 SNO-proteins were significantly regulated after excluding S-nitrosylation changes caused by protein expression alterations. Many of them belonged to mRNA splicing, ribosomal structure and translational regulatory proteins, covering the entire translation process. The results indicated that S-nitrosylation of the splicing and translational machinery in vascular endothelial cells was susceptible to ox-LDL. Abnormal protein S-nitrosylation may be one pivotal mechanism underlying endothelial dysfunction induced by ox-LDL. This study potentially enriches the present understanding of pro-atherogenic effect of ox-LDL from the perspective of S-nitrosylation. SIGNIFICANCE: The role of ox-LDL in endothelial dysfunction and atherosclerosis development has been recognized from the aspect of impaired NO production. However, its effect on S-nitrosylation, which is directly related to NO signaling pathway, still remains largely unexplored. Our work initially provided a systematic characterization of S-nitrosoproteome in ox-LDL-treated endothelial cells after ruling out the changes of S-nitrosylation modification caused by protein expression alone. MS-based approach coupled with iTRAQ technique indicated 262 SNO-proteins were significantly regulated. Functional enrichment and interaction network analysis revealed that proteins involved in mRNA splicing and translational machinery were susceptible to abnormal S-nitrosylation under ox-LDL treatment. This achievement suggested one potential mechanism underlying endothelial dysfunction induced by ox-LDL from the perspective of S-nitrosoproteome.
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Affiliation(s)
- Xiaohui Xu
- National Glycoengineering Research Center, The Key Laboratory of Cardiovascular Remodeling and Function Research, Chinese Ministry of Education, Chinese National Health Commission and Chinese Academy of Medical Sciences, The State and Shandong Province Joint Key Laboratory of Translational Cardiovascular Medicine, Qilu Hospital, Shandong University, Jinan, Shandong 250021, China
| | - Hongyan Qiu
- National Glycoengineering Research Center, The Key Laboratory of Cardiovascular Remodeling and Function Research, Chinese Ministry of Education, Chinese National Health Commission and Chinese Academy of Medical Sciences, The State and Shandong Province Joint Key Laboratory of Translational Cardiovascular Medicine, Qilu Hospital, Shandong University, Jinan, Shandong 250021, China
| | - Feng Shi
- Scientific Research Division, Shandong Institute for Food and Drug Control, Jinan, Shandong 250101, China
| | - Zhe Wang
- Division of Endocrinology and Metabolism, Provincial Hospital affiliated with Shandong University, Jinan, Shandong 250021, China
| | - Xiaowei Wang
- National Glycoengineering Research Center, The Key Laboratory of Cardiovascular Remodeling and Function Research, Chinese Ministry of Education, Chinese National Health Commission and Chinese Academy of Medical Sciences, The State and Shandong Province Joint Key Laboratory of Translational Cardiovascular Medicine, Qilu Hospital, Shandong University, Jinan, Shandong 250021, China
| | - Lan Jin
- National Glycoengineering Research Center, The Key Laboratory of Cardiovascular Remodeling and Function Research, Chinese Ministry of Education, Chinese National Health Commission and Chinese Academy of Medical Sciences, The State and Shandong Province Joint Key Laboratory of Translational Cardiovascular Medicine, Qilu Hospital, Shandong University, Jinan, Shandong 250021, China
| | - Lianli Chi
- National Glycoengineering Research Center, The Key Laboratory of Cardiovascular Remodeling and Function Research, Chinese Ministry of Education, Chinese National Health Commission and Chinese Academy of Medical Sciences, The State and Shandong Province Joint Key Laboratory of Translational Cardiovascular Medicine, Qilu Hospital, Shandong University, Jinan, Shandong 250021, China.
| | - Qunye Zhang
- National Glycoengineering Research Center, The Key Laboratory of Cardiovascular Remodeling and Function Research, Chinese Ministry of Education, Chinese National Health Commission and Chinese Academy of Medical Sciences, The State and Shandong Province Joint Key Laboratory of Translational Cardiovascular Medicine, Qilu Hospital, Shandong University, Jinan, Shandong 250021, China.
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4
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Mageeney CM, Kearse MG, Gershman BW, Pritchard CE, Colquhoun JM, Ware VC. Functional interplay between ribosomal protein paralogues in the eRpL22 family in Drosophila melanogaster. Fly (Austin) 2018; 12:143-163. [PMID: 30465696 DOI: 10.1080/19336934.2018.1549419] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Duplicated ribosomal protein (RP) genes in the Drosophila melanogaster eRpL22 family encode structurally-divergent and differentially-expressed rRNA-binding RPs. eRpL22 is expressed ubiquitously and eRpL22-like expression is tissue-restricted with highest levels in the adult male germline. We explored paralogue functional equivalence using the GAL4-UAS system for paralogue knockdown or overexpression and a conditional eRpL22-like knockout in a heat- shock flippase/FRT line. Ubiquitous eRpL22 knockdown with Actin-GAL4 resulted in embryonic lethality, confirming eRpL22 essentiality. eRpL22-like knockdown (60%) was insufficient to cause lethality; yet, conditional eRpL22-like knockout at one hour following egg deposition caused lethality within each developmental stage. Therefore, each paralogue is essential. Variation in timing of heat-shock-induced eRpL22-like knockout highlighted early embryogenesis as the critical period where eRpL22-like expression (not compensated for by eRpL22) is required for normal development of several organ systems, including testis development and subsequent sperm production. To determine if eRpL22-like can substitute for eRpL22, we used Actin-GAL4 for ubiquitous eRpL22 knockdown and eRpL22-like-FLAG (or FLAG-eRpL22: control) overexpression. Emergence of adults demonstrated that ubiquitous eRpL22-like-FLAG or FLAG-eRpL22 expression eliminates embryonic lethality resulting from eRpL22 depletion. Adults rescued by eRpL22-like-FLAG (but not by FLAG-eRpL22) overexpression had reduced fertility and longevity. We conclude that eRpL22 paralogue roles are not completely interchangeable and include functionally-diverse roles in development and spermatogenesis. Testis-specific paralogue knockdown revealed molecular phenotypes, including increases in eRpL22 protein and mRNA levels following eRpL22-like depletion, implicating a negative crosstalk mechanism regulating eRpL22 expression. Paralogue depletion unmasked mechanisms, yet to be defined that impact paralogue co-expression within germ cells.
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Affiliation(s)
| | - Michael G Kearse
- a Department of Biological Sciences , Lehigh University , Bethlehem , PA , USA
| | - Brett W Gershman
- a Department of Biological Sciences , Lehigh University , Bethlehem , PA , USA
| | | | | | - Vassie C Ware
- a Department of Biological Sciences , Lehigh University , Bethlehem , PA , USA
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5
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Fahl SP, Harris B, Coffey F, Wiest DL. Rpl22 Loss Impairs the Development of B Lymphocytes by Activating a p53-Dependent Checkpoint. THE JOURNAL OF IMMUNOLOGY 2016; 194:200-9. [PMID: 25416806 DOI: 10.4049/jimmunol.1402242] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Although ribosomal proteins facilitate the ribosome’s core function of translation, emerging evidence suggests that some ribosomal proteins are also capable of performing tissue-restricted functions either from within specialized ribosomes or from outside of the ribosome. In particular, we have previously demonstrated that germline ablation of the gene encoding ribosomal protein Rpl22 causes a selective and p53-dependent arrest of ab T cell progenitors at the b-selection checkpoint. We have now identified a crucial role for Rpl22 during early B cell development. Germline ablation of Rpl22 results in a reduction in the absolute number of B-lineage progenitors in the bone marrow beginning at the pro–B cell stage. Although Rpl22-deficient pro–B cells are hyporesponsive to IL-7, a key cytokine required for early B cell development, the arrest of B cell development does not result from disrupted IL-7 signaling. Instead, p53 induction appears to be responsible for the developmental defects, as Rpl22 deficiency causes increased expression of p53 and activation of downstream p53 target genes, and p53 deficiency rescues the defect in B cell development in Rpl22-deficient mice. Interestingly, the requirement for Rpl22 in the B cell lineage appears to be developmentally restricted, because Rpl22-deficient splenic B cells proliferate normally in response to Ag receptor and Toll receptor stimuli and undergo normal class-switch recombination. These results indicate that Rpl22 performs a critical, developmentally restricted role in supporting early B cell development by preventing p53 induction.
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Affiliation(s)
- Shawn P Fahl
- Immune Cell Development and Host Defense Program, Fox Chase Cancer Center, Philadelphia, PA 19111
| | - Bryan Harris
- Immune Cell Development and Host Defense Program, Fox Chase Cancer Center, Philadelphia, PA 19111
| | - Francis Coffey
- Immune Cell Development and Host Defense Program, Fox Chase Cancer Center, Philadelphia, PA 19111
| | - David L Wiest
- Immune Cell Development and Host Defense Program, Fox Chase Cancer Center, Philadelphia, PA 19111
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6
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Yang M, Sun H, He J, Wang H, Yu X, Ma L, Zhu C. Interaction of ribosomal protein L22 with casein kinase 2α: a novel mechanism for understanding the biology of non-small cell lung cancer. Oncol Rep 2014; 32:139-44. [PMID: 24840952 DOI: 10.3892/or.2014.3187] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2014] [Accepted: 04/15/2014] [Indexed: 11/06/2022] Open
Abstract
Dysfunction of ribosomal proteins (RPs) may play an important role in molecular tumorigenesis, such as lung cancer, acting in extraribosomal functions. Many protein-protein interaction studies and genetic screens have confirmed the extraribosomal capacity of RPs. As reported, ribosomal protein L22 (RPL22) dysfunction could increase cancer risk. In the present study, we examined RPL22-protein complexes in lung cancer cells. Tandem affinity purification (TAP) was used to screen the RPL22-protein complexes, and GST pull-down experiments and confocal microscopy were used to assess the protein-protein interaction. The experiment of kinase assay was used to study the function of the RPL22-protein complexes. The results showed that several differentially expressed proteins were isolated and identified by LC-MS/MS, which revealed that one of the protein complexes included casein kinase 2α (CK2α). RPL22 and CK2α interact in vitro. RPL22 also inhibited CK2α substrate phosphorylation in vitro. This is the first report of the RPL22-CK2α relationship in lung cancer. Dysregulated CK2 may impact cell proliferation and apoptosis, key features of cancer cell biology. Our results indicate that RPL22 may be a candidate anticancer agent due to its CK2α-binding and -inhibitory functions in human lung cancer.
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Affiliation(s)
- Mingxia Yang
- Department of Respiratory Medicine, The Affiliated Changzhou No. 2 People's Hospital, Nanjing Medical University, Changzhou, Jiangsu 213000, P.R. China
| | - Haibo Sun
- Department of Pathogen Biology, Nanjing Medical University, Nanjing, Jiangsu 210029, P.R. China
| | - Ji He
- State Key Laboratory of Monitoring and Detection for Medical Vectors, Xiamen Entry-Exit Inspection and Quarantine Bureau, Xiamen, Fujian 361012, P.R. China
| | - Hong Wang
- Department of Respiratory Medicine, The First Affiliated Hospital, Nanjing Medical University, Nanjing, Jiangsu 210029, P.R. China
| | - Xiaowei Yu
- Department of Respiratory Medicine, The Affiliated Changzhou No. 2 People's Hospital, Nanjing Medical University, Changzhou, Jiangsu 213000, P.R. China
| | - Lei Ma
- Department of Pathogen Biology, Nanjing Medical University, Nanjing, Jiangsu 210029, P.R. China
| | - Changliang Zhu
- Department of Pathogen Biology, Nanjing Medical University, Nanjing, Jiangsu 210029, P.R. China
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7
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O'Leary MN, Schreiber KH, Zhang Y, Duc ACE, Rao S, Hale JS, Academia EC, Shah SR, Morton JF, Holstein CA, Martin DB, Kaeberlein M, Ladiges WC, Fink PJ, MacKay VL, Wiest DL, Kennedy BK. The ribosomal protein Rpl22 controls ribosome composition by directly repressing expression of its own paralog, Rpl22l1. PLoS Genet 2013; 9:e1003708. [PMID: 23990801 PMCID: PMC3750023 DOI: 10.1371/journal.pgen.1003708] [Citation(s) in RCA: 74] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2013] [Accepted: 06/25/2013] [Indexed: 12/31/2022] Open
Abstract
Most yeast ribosomal protein genes are duplicated and their characterization has led to hypotheses regarding the existence of specialized ribosomes with different subunit composition or specifically-tailored functions. In yeast, ribosomal protein genes are generally duplicated and evidence has emerged that paralogs might have specific roles. Unlike yeast, most mammalian ribosomal proteins are thought to be encoded by a single gene copy, raising the possibility that heterogenous populations of ribosomes are unique to yeast. Here, we examine the roles of the mammalian Rpl22, finding that Rpl22−/− mice have only subtle phenotypes with no significant translation defects. We find that in the Rpl22−/− mouse there is a compensatory increase in Rpl22-like1 (Rpl22l1) expression and incorporation into ribosomes. Consistent with the hypothesis that either ribosomal protein can support translation, knockdown of Rpl22l1 impairs growth of cells lacking Rpl22. Mechanistically, Rpl22 regulates Rpl22l1 directly by binding to an internal hairpin structure and repressing its expression. We propose that ribosome specificity may exist in mammals, providing evidence that one ribosomal protein can influence composition of the ribosome by regulating its own paralog. Translation is the process by which proteins are made within a cell. Ribosomes are the main macromolecular complexes involved in this process. Ribosomes are composed of ribosomal RNA and ribosomal proteins. Ribosomal proteins are generally thought to be structural components of the ribosome but recent findings have suggested that they might have a regulatory function as well. A growing number of human diseases have been linked to mutations in genes encoding factors involved in ribosome biogenesis and translation. These include developmental malformations, inherited bone marrow failure syndromes and cancer in a variety of organisms. Here, we describe the role of one ribosomal protein regulating another. We provide evidence that ribosomal proteins can influence the composition of the ribosome, which we hypothesize, may impact the function of the ribosome.
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Affiliation(s)
- Monique N. O'Leary
- Department of Biochemistry, University of Washington, Seattle, Washington, United States of America
- Buck Institute for Research on Aging, Novato, California, United States of America
| | - Katherine H. Schreiber
- Department of Biochemistry, University of Washington, Seattle, Washington, United States of America
- Buck Institute for Research on Aging, Novato, California, United States of America
| | - Yong Zhang
- Blood Cell Development and Cancer Keystone, Immune Cell Development and Host Defense Program, Fox Chase Cancer Center, Philadelphia, Pennsylvania, United States of America
| | - Anne-Cécile E. Duc
- Blood Cell Development and Cancer Keystone, Immune Cell Development and Host Defense Program, Fox Chase Cancer Center, Philadelphia, Pennsylvania, United States of America
| | - Shuyun Rao
- Blood Cell Development and Cancer Keystone, Immune Cell Development and Host Defense Program, Fox Chase Cancer Center, Philadelphia, Pennsylvania, United States of America
| | - J. Scott Hale
- Department of Immunology, University of Washington, Seattle, Washington, United States of America
| | - Emmeline C. Academia
- Buck Institute for Research on Aging, Novato, California, United States of America
| | - Shreya R. Shah
- Department of Biochemistry, University of Washington, Seattle, Washington, United States of America
| | - John F. Morton
- Department of Comparative Medicine, University of Washington, Seattle, Washington, United States of America
| | - Carly A. Holstein
- Institute for Systems Biology, Seattle, Washington, United States of America
| | - Dan B. Martin
- Institute for Systems Biology, Seattle, Washington, United States of America
| | - Matt Kaeberlein
- Department of Pathology, University of Washington, Seattle, Washington, United States of America
| | - Warren C. Ladiges
- Department of Comparative Medicine, University of Washington, Seattle, Washington, United States of America
| | - Pamela J. Fink
- Department of Immunology, University of Washington, Seattle, Washington, United States of America
| | - Vivian L. MacKay
- Department of Biochemistry, University of Washington, Seattle, Washington, United States of America
| | - David L. Wiest
- Blood Cell Development and Cancer Keystone, Immune Cell Development and Host Defense Program, Fox Chase Cancer Center, Philadelphia, Pennsylvania, United States of America
| | - Brian K. Kennedy
- Department of Biochemistry, University of Washington, Seattle, Washington, United States of America
- Buck Institute for Research on Aging, Novato, California, United States of America
- * E-mail:
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8
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Kearse MG, Ireland JA, Prem SM, Chen AS, Ware VC. RpL22e, but not RpL22e-like-PA, is SUMOylated and localizes to the nucleoplasm of Drosophila meiotic spermatocytes. Nucleus 2013; 4:241-58. [PMID: 23778934 DOI: 10.4161/nucl.25261] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
Duplicated ribosomal protein (Rp) gene families often encode highly similar or identical proteins with redundant or unique roles. Eukaryotic-specific paralogues RpL22e and RpL22e-like-PA are structurally divergent within the N terminus and differentially expressed, suggesting tissue-specific functions. We previously identified RpL22e-like-PA as a testis Rp. Strikingly, RpL22e is detected in immunoblots at its expected molecular mass (m) of 33 kD and at increasing m of ~43-55 kD, suggesting RpL22e post-translational modification (PTM). Numerous PTMs, including N-terminal SUMOylation, are predicted computationally. Based on S2 cell co-immunoprecipitations, bacterial-based SUMOylation assays and in vivo germline-specific RNAi depletion of SUMO, we conclude that RpL22e is a SUMO substrate. Testis-specific PTMs are evident, including a phosphorylated version of SUMOylated RpL22e identified by in vitro phosphatase experiments. In ribosomal profiles from S2 cells, only unconjugated RpL22e co-sediments with active ribosomes, supporting an extra-translational role for SUMOylated RpL22e. Ectopic expression of an RpL22e N-terminal deletion (lacking SUMO motifs) shows that truncated RpL22e co-sediments with polysomes, implying that RpL22e SUMOylation is dispensable for ribosome biogenesis and function. In mitotic germ cells, both paralogues localize within the cytoplasm and nucleolus. However, within meiotic cells, phase contrast microscopy and co-immunohistochemical analysis with nucleolar markers nucleostemin1 and fibrillarin reveals diffuse nucleoplasmic, but not nucleolar RpL22e localization that transitions to a punctate pattern as meiotic cells mature, suggesting an RpL22e role outside of translation. Germline-specific knockdown of SUMO shows that RpL22e nucleoplasmic distribution is sensitive to SUMO levels, as immunostaining becomes more dispersed. Overall, these data suggest distinct male germline roles for RpL22e and RpL22e-like-PA.
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Affiliation(s)
- Michael G Kearse
- Department of Biological Sciences, Lehigh University, Bethlehem, PA, USA
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9
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Ayub MJ, Nyambega B, Simonetti L, Duffy T, Longhi SA, Gómez KA, Hoebeke J, Levin MJ, Smulski CR. Selective blockade of trypanosomatid protein synthesis by a recombinant antibody anti-Trypanosoma cruzi P2β protein. PLoS One 2012; 7:e36233. [PMID: 22570698 PMCID: PMC3343115 DOI: 10.1371/journal.pone.0036233] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2011] [Accepted: 03/28/2012] [Indexed: 11/18/2022] Open
Abstract
The ribosomal P proteins are located on the stalk of the ribosomal large subunit and play a critical role during the elongation step of protein synthesis. The single chain recombinant antibody C5 (scFv C5) directed against the C-terminal region of the Trypanosoma cruzi P2β protein (TcP2β) recognizes the conserved C-terminal end of all T. cruzi ribosomal P proteins. Although this region is highly conserved among different species, surface plasmon resonance analysis showed that the scFv C5 possesses very low affinity for the corresponding mammalian epitope, despite having only one single amino-acid change. Crystallographic analysis, in silico modelization and NMR assays support the analysis, increasing our understanding on the structural basis of epitope specificity. In vitro protein synthesis experiments showed that scFv C5 was able to specifically block translation by T. cruzi and Crithidia fasciculata ribosomes, but virtually had no effect on Rattus norvegicus ribosomes. Therefore, we used the scFv C5 coding sequence to make inducible intrabodies in Trypanosoma brucei. Transgenic parasites showed a strong decrease in their growth rate after induction. These results strengthen the importance of the P protein C terminal regions for ribosomal translation activity and suggest that trypanosomatid ribosomal P proteins could be a possible target for selective therapeutic agents that could be derived from structural analysis of the scFv C5 antibody paratope.
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Affiliation(s)
- Maximiliano Juri Ayub
- Laboratorio de Biología Molecular de la Enfermedad de Chagas, Instituto de Investigaciones en Ingeniería Genética y Biología Molecular, Consejo Nacional de Investigaciones Científicas y Técnicas, Buenos Aires, Argentina
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10
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Lapadula WJ, Sanchez-Puerta MV, Juri Ayub M. Convergent evolution led ribosome inactivating proteins to interact with ribosomal stalk. Toxicon 2012; 59:427-32. [DOI: 10.1016/j.toxicon.2011.12.014] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2011] [Revised: 12/29/2011] [Accepted: 12/30/2011] [Indexed: 10/14/2022]
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11
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Capsaicin-enhanced Ribosomal Protein P2 Expression in Human Intestinal Caco-2 Cells. Cytotechnology 2011; 47:89-96. [PMID: 19003048 DOI: 10.1007/s10616-005-3756-5] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2004] [Accepted: 01/25/2005] [Indexed: 01/15/2023] Open
Abstract
On the basis of transepithelial electrical resistance (TER) measurements, we found that capsaicin (100 muM)-treated human intestinal Caco-2 cells show a momentary increase in tight-junction (TJ) permeability (decrease in TER) followed by a complete recovery. We used proteome analysis to search for proteins that are associated with the recovery of TJ permeability in capsaicin-treated Caco-2 cells. A protein with a relative molecular mass of 14 kDa was found to be expressed more highly in capsaicin-treated cells than in nontreated cells. Mass spectrometry and sequence analyses revealed that the protein that is expressed significantly upon capsaicin treatment is the ribosomal protein P2; its cDNA sequence was identical to that found in the human genome database. An increase in the amount of cellular filamentous actin (F-actin) was shown after 8 h of incubation with capsaicin. It has been reported that P2 activates elongation factor 2, which stabilizes F-actin filaments, and that the depolymerization of F-actin is associated with the increase in TJ permeability (decrease in TER). Consequently, these results suggest that P2 plays an important role in the recovery of the TJ permeability in capsaicin-treated human intestinal cells.
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12
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Stadanlick JE, Zhang Z, Lee SY, Hemann M, Biery M, Carleton MO, Zambetti GP, Anderson SJ, Oravecz T, Wiest DL. Developmental arrest of T cells in Rpl22-deficient mice is dependent upon multiple p53 effectors. THE JOURNAL OF IMMUNOLOGY 2011; 187:664-75. [PMID: 21690328 DOI: 10.4049/jimmunol.1100029] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
αβ and γδ lineage T cells are thought to arise from a common CD4(-)CD8(-) progenitor in the thymus. However, the molecular pathways controlling fate selection and maturation of these two lineages remain poorly understood. We demonstrated recently that a ubiquitously expressed ribosomal protein, Rpl22, is selectively required for the development of αβ lineage T cells. Germline ablation of Rpl22 impairs development of αβ lineage, but not γδ lineage, T cells through activation of a p53-dependent checkpoint. In this study, we investigate the downstream effectors used by p53 to impair T cell development. We found that many p53 targets were induced in Rpl22(-/-) thymocytes, including miR-34a, PUMA, p21(waf), Bax, and Noxa. Notably, the proapoptotic factor Bim, while not a direct p53 target, was also strongly induced in Rpl22(-/-) T cells. Gain-of-function analysis indicated that overexpression of miR-34a caused a developmental arrest reminiscent of that induced by p53 in Rpl22-deficient T cells; however, only a few p53 targets alleviated developmental arrest when individually ablated by gene targeting or knockdown. Co-elimination of PUMA and Bim resulted in a nearly complete restoration of development of Rpl22(-/-) thymocytes, indicating that p53-mediated arrest is enforced principally through effects on cell survival. Surprisingly, co-elimination of the primary p53 regulators of cell cycle arrest (p21(waf)) and apoptosis (PUMA) actually abrogated the partial rescue caused by loss of PUMA alone, suggesting that the G1 checkpoint protein p21(waf) facilitates thymocyte development in some contexts.
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Affiliation(s)
- Jason E Stadanlick
- Immune Cell Development and Host Defense Program, Blood Cell Development and Cancer Keystone, Fox Chase Cancer Center, Philadelphia, PA 19111, USA
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13
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Cellular gene expression that correlates with EBER expression in Epstein-Barr Virus-infected lymphoblastoid cell lines. J Virol 2011; 85:3535-45. [PMID: 21248031 DOI: 10.1128/jvi.02086-10] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Novel Epstein-Barr Virus (EBV) strains with deletion of either EBER1 or EBER2 and corresponding revertant viruses were constructed and used to infect B lymphocytes to make lymphoblastoid cell lines (LCLs). The LCLs were used in microarray expression profiling to identify genes whose expression correlates with the presence of EBER1 or EBER2. Functions of regulated genes identified in the microarray analysis include membrane signaling, regulation of apoptosis, and the interferon/antiviral response. Although most emphasis has previously been given to EBER1 because it is more abundant than EBER2, the differences in cell gene expression were greater with EBER2 deletion. In this system, deletion of EBER1 or EBER2 had little effect on the EBV transformation frequency of primary B cells or the growth of the resulting LCLs. Using the recombinant viruses and novel EBER expression vectors, the nuclear redistribution of rpL22 protein by EBER1 in 293 cells was confirmed, but in LCLs almost all of the cells had a predominantly cytoplasmic expression of this ribosomal protein, which was not detectably changed by EBER1. The changes in LCL gene expression identified here will provide a basis for identifying the mechanisms of action of EBER RNAs.
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14
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Kearse MG, Chen AS, Ware VC. Expression of ribosomal protein L22e family members in Drosophila melanogaster: rpL22-like is differentially expressed and alternatively spliced. Nucleic Acids Res 2010; 39:2701-16. [PMID: 21138957 PMCID: PMC3074143 DOI: 10.1093/nar/gkq1218] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
Abstract
Several ribosomal protein families contain paralogues whose roles may be equivalent or specialized to include extra-ribosomal functions. RpL22e family members rpL22 and rpL22-like are differentially expressed in Drosophila melanogaster: rpL22-like mRNA is gonad specific whereas rpL22 is expressed ubiquitously, suggesting distinctive paralogue functions. To determine if RpL22-like has a divergent role in gonads, rpL22-like expression was analysed by qRT-PCR and western blots, respectively, showing enrichment of rpL22-like mRNA and a 34 kDa (predicted) protein in testis, but not in ovary. Immunohistochemistry of the reproductive tract corroborated testis-specific expression. RpL22-like detection in 80S/polysome fractions from males establishes a role for this tissue-specific paralogue as a ribosomal component. Unpredictably, expression profiles revealed a low abundant, alternative mRNA variant (designated 'rpL22-like short') that would encode a novel protein lacking the C-terminal ribosomal protein signature but retaining part of the N-terminal domain. This variant results from splicing of a retained intron (defined by non-canonical splice sites) within rpL22-like mRNA. Polysome association and detection of a low abundant 13.5 kDa (predicted) protein in testis extracts suggests variant mRNA translation. Collectively, our data show that alternative splicing of rpL22-like generates structurally distinct protein products: ribosomal component RpL22-like and a novel protein with a role distinct from RpL22-like.
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Affiliation(s)
| | | | - Vassie C. Ware
- *To whom correspondence should be addressed. Tel: +610 758 3690; Fax: +610 758 4004;
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15
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Sugihara Y, Honda H, Iida T, Morinaga T, Hino S, Okajima T, Matsuda T, Nadano D. Proteomic Analysis of Rodent Ribosomes Revealed Heterogeneity Including Ribosomal Proteins L10-like, L22-like 1, and L39-like. J Proteome Res 2010; 9:1351-66. [DOI: 10.1021/pr9008964] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Affiliation(s)
- Yoshihiko Sugihara
- Department of Applied Molecular Biosciences, Graduate School of Bioagricultural Sciences, Nagoya University, Nagoya 464-8601, Japan
| | - Hiroki Honda
- Department of Applied Molecular Biosciences, Graduate School of Bioagricultural Sciences, Nagoya University, Nagoya 464-8601, Japan
| | - Tomoharu Iida
- Department of Applied Molecular Biosciences, Graduate School of Bioagricultural Sciences, Nagoya University, Nagoya 464-8601, Japan
| | - Takuma Morinaga
- Department of Applied Molecular Biosciences, Graduate School of Bioagricultural Sciences, Nagoya University, Nagoya 464-8601, Japan
| | - Shingo Hino
- Department of Applied Molecular Biosciences, Graduate School of Bioagricultural Sciences, Nagoya University, Nagoya 464-8601, Japan
| | - Tetsuya Okajima
- Department of Applied Molecular Biosciences, Graduate School of Bioagricultural Sciences, Nagoya University, Nagoya 464-8601, Japan
| | - Tsukasa Matsuda
- Department of Applied Molecular Biosciences, Graduate School of Bioagricultural Sciences, Nagoya University, Nagoya 464-8601, Japan
| | - Daita Nadano
- Department of Applied Molecular Biosciences, Graduate School of Bioagricultural Sciences, Nagoya University, Nagoya 464-8601, Japan
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16
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Growth-promoting properties of Epstein-Barr virus EBER-1 RNA correlate with ribosomal protein L22 binding. J Virol 2009; 83:9844-53. [PMID: 19640998 DOI: 10.1128/jvi.01014-09] [Citation(s) in RCA: 51] [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 Epstein-Barr virus (EBV)-encoded RNAs, EBER-1 and EBER-2, are highly abundant noncoding nuclear RNAs expressed during all forms of EBV latency. The EBERs have been shown to impart significant tumorigenic potential upon EBV-negative Burkitt lymphoma (BL) cells and to contribute to the growth potential of other B-cell lymphoma-, gastric carcinoma-, and nasopharyngeal carcinoma-derived cell lines. However, the mechanisms underlying this EBER-dependent enhancement of cell growth potential remain to be elucidated. Here we focused on the known interaction between EBER-1 and the cellular ribosomal protein L22 and the consequences of this interaction with respect to the growth-promoting properties of the EBERs. L22, a component of 60S ribosomal subunits, binds three sites on EBER-1, and a substantial fraction of available L22 is relocalized from nucleoli to the nucleoplasm in EBV-infected cells. To investigate the hypothesis that EBER-1-mediated relocalization of L22 in EBV-infected cells is critical for EBER-dependent functions, we investigated whether EBER-1 expression is necessary and sufficient for nucleoplasmic retention of L22. Following demonstration of this, we utilized RNA-protein binding assays and fluorescence localization studies to demonstrate that mutation of the L22 binding sites on EBER-1 prevents L22 binding and inhibits EBER-1-dependent L22 relocalization. Finally, the in vivo consequence of preventing L22 relocalization in EBER-expressing cells was examined in soft agar colony formation assays. We demonstrate that BL cells expressing mutated EBER-1 RNAs rendered incapable of binding L22 have significantly reduced capacity to enhance cell growth potential relative to BL cells expressing wild-type EBERs.
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17
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Abstract
Anti-ribosomal P protein antibodies (Abs) recognize three specific ribosomal proteins located in the large ribosome's subunit. The term anti-ribosomal P protein Abs, often shortened in anti-P Abs, is due to the fact that these three proteins, P0, P1 and P2, of 38, 19 and 17 Kd molecular weight, respectively, are phosphorylated. One of the major points of interest of these autoAbs derives from their high specificity for systemic lupus erythematosus (SLE), their description in other connective tissue diseases (CTDs) being only occasional. In SLE patients, their association with renal and hepatic involvement has been proposed, while the possible association with psychiatric and/or neurological involvement is still a matter of debate. From a serological point of view, a preferential association of anti-P with anti-Sm and/or anti-DNA Abs, possibly due, at least in part, to cross-reactivity, has been suggested. This observation is intriguing since all these autoAbs are considered specific serological indicators of SLE. This review will summarize clinical and serological data on anti-P Abs provided by the main studies published in the last few years and the more recent findings about proteins constituting their targets.
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Affiliation(s)
- Roberto Gerli
- Department of Clinical and Experimental Medicine, Center for the Study of Rheumatic Diseases, University of Perugia 06122, Italy.
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18
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Houmani JL, Ruf IK. Clusters of basic amino acids contribute to RNA binding and nucleolar localization of ribosomal protein L22. PLoS One 2009; 4:e5306. [PMID: 19390581 PMCID: PMC2668802 DOI: 10.1371/journal.pone.0005306] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2009] [Accepted: 03/26/2009] [Indexed: 11/19/2022] Open
Abstract
The ribosomal protein L22 is a component of the 60S eukaryotic ribosomal subunit. As an RNA-binding protein, it has been shown to interact with both cellular and viral RNAs including 28S rRNA and the Epstein-Barr virus encoded RNA, EBER-1. L22 is localized to the cell nucleus where it accumulates in nucleoli. Although previous studies demonstrated that a specific amino acid sequence is required for nucleolar localization, the RNA-binding domain has not been identified. Here, we investigated the hypothesis that the nucleolar accumulation of L22 is linked to its ability to bind RNA. To address this hypothesis, mutated L22 proteins were generated to assess the contribution of specific amino acids to RNA binding and protein localization. Using RNA-protein binding assays, we demonstrate that basic amino acids 80-93 are required for high affinity binding of 28S rRNA and EBER-1 by L22. Fluorescence localization studies using GFP-tagged mutated L22 proteins further reveal that basic amino acids 80-93 are critical for nucleolar accumulation and for incorporation into ribosomes. Our data support the growing consensus that the nucleolar accumulation of ribosomal proteins may not be mediated by a defined localization signal, but rather by specific interaction with established nucleolar components such as rRNA.
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Affiliation(s)
- Jennifer L. Houmani
- Department of Molecular Biology and Biochemistry, University of California Irvine, Irvine, California, United States of America
| | - Ingrid K. Ruf
- Department of Molecular Biology and Biochemistry, University of California Irvine, Irvine, California, United States of America
- * E-mail:
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19
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Anderson SJ, Lauritsen JPH, Hartman MG, Foushee AMD, Lefebvre JM, Shinton SA, Gerhardt B, Hardy RR, Oravecz T, Wiest DL. Ablation of ribosomal protein L22 selectively impairs alphabeta T cell development by activation of a p53-dependent checkpoint. Immunity 2007; 26:759-72. [PMID: 17555992 DOI: 10.1016/j.immuni.2007.04.012] [Citation(s) in RCA: 149] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2006] [Revised: 02/27/2007] [Accepted: 04/10/2007] [Indexed: 10/23/2022]
Abstract
The alphabeta and gammadelta T lineages are thought to arise from a common precursor; however, the regulation of separation and development of these lineages is not fully understood. We report here that development of alphabeta and gammadelta precursors was differentially affected by elimination of ribosomal protein L22 (Rpl22), which is ubiquitously expressed but not essential for translation. Rpl22 deficiency selectively arrested development of alphabeta-lineage T cells at the beta-selection checkpoint by inducing their death. The death was caused by induction of p53 expression, because p53 deficiency blocked death and restored development of Rpl22-deficient thymocytes. Importantly, Rpl22 deficiency led to selective upregulation of p53 in alphabeta-lineage thymocytes, at least in part by increasing p53 synthesis. Taken together, these data indicate that Rpl22 deficiency activated a p53-dependent checkpoint that produced a remarkably selective block in alphabeta T cell development but spared gammadelta-lineage cells, suggesting that some ribosomal proteins may perform cell-type-specific or stage-specific functions.
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Affiliation(s)
- Stephen J Anderson
- Division of Immunology and Hematology, Lexicon Genetics, Inc., 8800 Technology Forest Place, The Woodlands, TX 77381, USA
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20
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Qiu D, Parada P, Marcos AG, Cárdenas D, Remacha M, Ballesta JPG. Different roles of P1 and P2 Saccharomyces cerevisiae ribosomal stalk proteins revealed by cross-linking. Mol Microbiol 2006; 62:1191-202. [PMID: 17040491 DOI: 10.1111/j.1365-2958.2006.05445.x] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The stalk is an essential domain of the large ribosomal subunit formed by a complex of a set of very acidic proteins bound to a core rRNA binding component. While in prokaryotes there is only one type acidic protein, L7/12, two protein families are found in eukaryotes, phosphoproteins P1 and P2, which presumably have different roles. To search for differences zero-length cross-linking by S-S bridge formation was applied using Saccharomyces cerevisiae mutant P1 and P2 proteins carrying single cysteine residues at various positions. The results show a more exposed location of the N-terminal domain of the P2 proteins, which in contrast to P1, can be found as dimers when the Cys is introduced in this domain. Similarly, the Cys containing C-terminal domain of mutant P2 proteins shows a notable capacity to form cross-links with other proteins, which is considerably lower in the P1 type. On the other hand, mutation at the conserved C-domain of protein P0, the eukaryotic stalk rRNA binding component, results in removal of about 14 terminal amino acids. Protein P2, but not P1, protects mutant P0 from this truncation. These results support a eukaryotic stalk structure in which P1 proteins are internally located with their C-terminals having a restricted reactivity while P2 proteins are more external and accessible to interact with other cellular components.
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Affiliation(s)
- Deyi Qiu
- Centro de Biología Molecular, C.S.I.C. and U.A.M., Canto Blanco, Madrid 28049, Spain
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21
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Krokowski D, Boguszewska A, Abramczyk D, Liljas A, Tchórzewski M, Grankowski N. Yeast ribosomal P0 protein has two separate binding sites for P1/P2 proteins. Mol Microbiol 2006; 60:386-400. [PMID: 16573688 DOI: 10.1111/j.1365-2958.2006.05117.x] [Citation(s) in RCA: 70] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
The ribosome has a distinct lateral protuberance called the stalk; in eukaryotes it is formed by the acidic ribosomal P-proteins which are organized as a pentameric entity described as P0-(P1-P2)(2). Bilateral interactions between P0 and P1/P2 proteins have been studied extensively, however, the region on P0 responsible for the binding of P1/P2 proteins has not been precisely defined. Here we report a study which takes the current knowledge of the P0 - P1/P2 protein interaction beyond the recently published information. Using truncated forms of P0 protein and several in vitro and in vivo approaches, we have defined the region between positions 199 and 258 as the P0 protein fragment responsible for the binding of P1/P2 proteins in the yeast Saccharomyces cerevisiae. We show two short amino acid regions of P0 protein located at positions 199-230 and 231-258, to be responsible for independent binding of two dimers, P1A-P2B and P1B-P2A respectively. In addition, two elements, the sequence spanning amino acids 199-230 and the P1A-P2B dimer were found to be essential for stalk formation, indicating that this process is dependent on a balance between the P1A-P2B dimer and the P0 protein.
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Affiliation(s)
- Dawid Krokowski
- Department of Molecular Biology, Institute of Microbiology and Biotechnology, Maria Curie-Skodowska University, Akademicka 19, 20-033 Lublin, Poland
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22
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Ersvaer E, Bertelsen LT, Espenes LC, Bredholt T, Bøe SO, Iversen BM, Bruserud Ø, Ulvestad E, Gjertsen BT. Characterization of Ribosomal P Autoantibodies in Relation to Cell Destruction and Autoimmune Disease. Scand J Immunol 2004; 60:189-98. [PMID: 15238089 DOI: 10.1111/j.0300-9475.2004.01450.x] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Autoantibodies against the ribosomal P proteins are related to cell death and tissue destruction and are frequently exhibited in patients with systemic lupus erythematosus (SLE). In an attempt to explore the effect of tissue destruction on the induction of anti-P autoantibodies, we searched for anti-P autoantibodies by enzyme-linked immunosorbent assay in 201 antinuclear antibody (ANA)-positive individuals, in 10 patients with treated kidney SLE and in 45 acute leukaemia patients undergoing intensive chemotherapy. The autoantibody reactivity was further characterized using one- and two-dimensional immunoblot analysis and immunofluorescence. Anti-P were detected in 5.5% (11/201) of ANA-positive individuals, but not in kidney-affected SLE patients or in patients with leukaemia. Seven of 11 anti-P-positive patients had SLE (3/11), primary Sjögrens's syndrome (1/11) and other autoimmune diseases (3/11). A relation between disease activity and anti-P was suggested by follow-up examinations in one SLE patient, supported by the absence of anti-P autoantibodies in the 10 treated kidney SLE patients. Anti-P autoantibodies were detected by immunoblot in one patient with SLE indicating anti-P2 predominance and in the patient with Sjögrens's syndrome indicating anti-P1 predominance. Diverging humoral responses in these ANA- and anti-P-positive patients were further illustrated by immunofluorescence, elucidating varying nuclear reactivity and anti-P pattern. The observation of anti-P in individuals with active autoimmune disease, but not in patients with chemotherapy-induced cell damage, suggests that anti-P antibodies are part of a specific disease process, and not elicited as a response to cell destruction per se.
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Affiliation(s)
- E Ersvaer
- Institute of Medicine and Department of Internal Medicine, Hematology Section, University of Bergen, Haukeland University Hospital, N-5021 Bergen, Norway
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23
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Lalioti VS, Pérez-Fernández J, Remacha M, Ballesta JPG. Characterization of interaction sites in the Saccharomyces cerevisiae ribosomal stalk components. Mol Microbiol 2002; 46:719-29. [PMID: 12410829 DOI: 10.1046/j.1365-2958.2002.03179.x] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
The interactions among the yeast stalk components (P0, P1alpha, P1beta, P2alpha and P2beta) and with EF-2 have been explored using immunoprecipitation, affinity chromatography and the two-hybrid system. No stable association was detected between acidic proteins of the same type. In contrast, P1alpha and P1beta were found to interact with P2beta and P2alpha respectively. An interaction of P0 with P1 proteins, but not with P2 proteins, was also detected. This interaction is strongly increased with the P0 carboxyl end, which is able to form a pentameric complex with the four acidic proteins. The P1/P2 binding site has been located between residues 212 and 262 using different C-terminal P0 fragments. Immunoprecipitation shows the association of EF-2 with protein P0. However, the interaction is stronger with the P1/P2 proteins than with P0 in the two-hybrid assay. This interaction improves using the 100-amino-acid-long C-end of P0 and is even higher with the last 50 amino acids. The data indicate a specific association of P1alpha with P2beta and of P1beta with P2alpha rather than the dimerization of the acidic proteins found in prokaryotes. In addition, they suggest that stalk assembly begins by the interaction of the P1 proteins with P0. Moreover, as functional interactions of the complete P0 were found to increase using protein fragments, the data suggest that some active sites are exposed in the ribosome as a result of conformational changes that take place during stalk assembly and function.
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Affiliation(s)
- V S Lalioti
- Centro de Biología Molecular Severo Ochoa, Universidad Autónoma de Madrid--CSIC, Cantoblanco, 28049 Madrid, Spain
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24
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Guarinos E, Remacha M, Ballesta JP. Asymmetric interactions between the acidic P1 and P2 proteins in the Saccharomyces cerevisiae ribosomal stalk. J Biol Chem 2001; 276:32474-9. [PMID: 11431471 DOI: 10.1074/jbc.m103229200] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The Saccharomyces cerevisiae ribosomal stalk is made of five components, the 32-kDa P0 and four 12-kDa acidic proteins, P1alpha, P1beta, P2alpha, and P2beta. The P0 carboxyl-terminal domain is involved in the interaction with the acidic proteins and resembles their structure. Protein chimeras were constructed in which the last 112 amino acids of P0 were replaced by the sequence of each acidic protein, yielding four fusion proteins, P0-1alpha, P0-1beta, P0-2alpha, and P0-2beta. The chimeras were expressed in P0 conditional null mutant strains in which wild-type P0 is not present. In S. cerevisiae D4567, which is totally deprived of acidic proteins, the four fusion proteins can replace the wild-type P0 with little effect on cell growth. In other genetic backgrounds, the chimeras either reduce or increase cell growth because of their effect on the ribosomal stalk composition. An analysis of the stalk proteins showed that each P0 chimera is able to strongly interact with only one acidic protein. The following associations were found: P0-1alpha.P2beta, P0-1beta.P2alpha, P0-2alpha.P1beta, and P0-2beta.P1alpha. These results indicate that the four acidic proteins do not form dimers in the yeast ribosomal stalk but interact with each other forming two specific associations, P1alpha.P2beta and P1beta.P2alpha, which have different structural and functional roles.
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Affiliation(s)
- E Guarinos
- Centro de Biologia Molecular, Consejo Superior de Investigaciones Cientificas and Universidad Autónoma de Madrid, Canto Blanco, 28049 Madrid, Spain
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25
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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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26
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Le S, Sternglanz R, Greider CW. Identification of two RNA-binding proteins associated with human telomerase RNA. Mol Biol Cell 2000; 11:999-1010. [PMID: 10712515 PMCID: PMC14826 DOI: 10.1091/mbc.11.3.999] [Citation(s) in RCA: 105] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
Abstract
Telomerase plays a crucial role in telomere maintenance in vivo. To understand telomerase regulation, we have been characterizing components of the enzyme. To date several components of the mammalian telomerase holoenzyme have been identified: the essential RNA component (human telomerase RNA [hTR]), the catalytic subunit human telomerase reverse transcriptase (hTERT), and telomerase-associated protein 1. Here we describe the identification of two new proteins that interact with hTR: hStau and L22. Antisera against both proteins immunoprecipitated hTR, hTERT, and telomerase activity from cell extracts, suggesting that the proteins are associated with telomerase. Both proteins localized to the nucleolus and cytoplasm. Although these proteins are associated with telomerase, we found no evidence of their association with each other or with telomerase-associated protein 1. Both hStau and L22 are more abundant than TERT. This, together with their localization, suggests that they may be associated with other ribonucleoprotein complexes in cells. We propose that these two hTR-associated proteins may play a role in hTR processing, telomerase assembly, or localization in vivo.
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Affiliation(s)
- S Le
- Department of Molecular Biology and Genetics, The Johns Hopkins University School of Medicine, Baltimore, Maryland 21205, USA
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27
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Ballesta JP, Rodriguez-Gabriel MA, Bou G, Briones E, Zambrano R, Remacha M. Phosphorylation of the yeast ribosomal stalk. Functional effects and enzymes involved in the process. FEMS Microbiol Rev 1999; 23:537-50. [PMID: 10525165 DOI: 10.1111/j.1574-6976.1999.tb00412.x] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
Abstract
The ribosomal stalk is directly involved in the interaction of the elongation factors with the ribosome during protein synthesis. The stalk is formed by a complex of five proteins, four small acidic polypeptides and a larger protein which directly interacts with the rRNA at the GTPase center. In eukaryotes the acidic components correspond to the 12-kDa P1 and P2 proteins, and the RNA binding component is the P0 protein. All these proteins are found phosphorylated in eukaryotic organisms, and previous in vitro data suggested this modification was involved in the activity of this structure. Results from mutational studies have shown that phosphorylation takes place at a serine residue close to the carboxy end of the P proteins. Modification of this serine residue does not affect the formation of the stalk and the activity of the ribosome in standard conditions but induces an osmoregulation-related phenotype at 37 degrees C. The phosphorylatable serine is part of a consensus casein kinase II phosphorylation site. However, although CKII seems to be responsible for part of the stalk phosphorylation in vivo, it is probably not the only enzyme in the cell able to perform this modification. Five protein kinases, RAPI, RAPII and RAPIII, in addition to the previously reported CKII and PK60 kinases, are able to phosphorylate the stalk proteins. A comparison of the five enzymes shows differences among them that suggest some specificity regarding the phosphorylation of the four yeast acidic proteins. It has been found that some typical effectors of the PKC kinase stimulate the in vitro phosphorylation of the stalk proteins. All the data suggest that although phosphorylation is not involved in the interaction of the acidic P proteins with the ribosome, it can affect the ribosome activity and might participate in a possible ribosome regulatory mechanism.
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Affiliation(s)
- J P Ballesta
- Centro de Biología Molecular, CSIC and UAM, Canto Blanco, 28049, Madrid, Spain.
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28
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Bargis-Surgey P, Lavergne JP, Gonzalo P, Vard C, Filhol-Cochet O, Reboud JP. Interaction of elongation factor eEF-2 with ribosomal P proteins. EUROPEAN JOURNAL OF BIOCHEMISTRY 1999; 262:606-11. [PMID: 10336649 DOI: 10.1046/j.1432-1327.1999.00434.x] [Citation(s) in RCA: 68] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
The eukaryotic P1 and P2 ribosomal proteins which constitute, with P0, a pentamer forming the lateral stalk of the 60 S ribosomal subunit, exhibit several differences from their prokaryotic equivalents L7 and L12; in particular, P1 does not have the same primary structure as P2 and both of them are phosphorylated, the significance of the latter remaining unclear. Rat liver P1 and P2 were overproduced in Escherichia coli cells and their interaction with elongation factor eEF-2 was studied. Both recombinant proteins were found to be required for the ribosome-dependent GTPase activity of eEF-2, with P2 in the phosphorylated form. The surface plasmon resonance technique revealed that, in vitro, both proteins interact specifically with eEF-2, with a higher affinity for P1 (Kd = 3.8 x 10-8 m) than for P2 (Kd = 2.2 x 10-6 m). Phosphorylation resulted in a moderate increase (two- to four-fold) in these affinities. The interaction of both P1 and P2 (phosphorylated or not) with eEF-2 resulted in a conformational change in the factor, revealed by an increase in the accessibility of Glu554 to proteinase Glu-C. This increase was observed in both the presence and absence of GTP and GDP, which themselves produced marked opposite effects on the conformation of eEF-2. Our results suggest that the two proteins P1 and P2 both interact with eEF-2 inducing a conformational transition of the factor, but have acquired some specific properties during evolution.
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Affiliation(s)
- P Bargis-Surgey
- Laboratoire de Biochimie Médicale, Institut de Biologie et Chimie des Protéines, CNRS, Lyon, France
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29
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Vard C, Guillot D, Bargis P, Lavergne JP, Reboud JP. A specific role for the phosphorylation of mammalian acidic ribosomal protein P2. J Biol Chem 1997; 272:20259-62. [PMID: 9242705 DOI: 10.1074/jbc.272.32.20259] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
The acidic ribosomal proteins P1-P2 from rat liver were overproduced for the first time by expression of their cDNA in Escherichia coli. They were tested for their ability to reactivate inactive P1-P2-deficient core particles derived from 60 S ribosomal subunits treated with dimethylmaleic anhydride, in poly(U)-directed poly(Phe) synthesis. The recombinant P1-P2 were unable to reactivate these core particles although they could bind to them. When recombinant P1-P2 had been phosphorylated first with casein kinase II, they were as efficient in the reactivation process as P1-P2 extracted with ethanol/KCl from the 60 S subunits. Reconstitution experiments were carried out using all possible combinations of the two recombinant proteins phosphorylated or not. Reactivation of the core particles required the presence of both P1 and P2 with the latter in its phosphorylated form. These experiments reveal a distinct role for P1 and P2 in protein synthesis. Phosphorylated P2 produced a partial quenching of the intrinsic fluorescence of eukaryotic elongation factor 2, which was not observed with the unphosphorylated protein. This result demonstrates the existence of an interaction between phosphorylated P2 and eukaryotic elongation factor 2. P2 also quenched part of the intrinsic fluorescence of P1, due to the interaction between the two proteins.
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Affiliation(s)
- C Vard
- Laboratoire de Biochimie Médicale, Institut de Biologie et Chimie des Protéines, Centre National de la Recherche Scientifique, 7, passage du Vercors, 69367 Lyon Cedex 07, France
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30
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Dobbelstein M, Shenk T. In vitro selection of RNA ligands for the ribosomal L22 protein associated with Epstein-Barr virus-expressed RNA by using randomized and cDNA-derived RNA libraries. J Virol 1995; 69:8027-34. [PMID: 7494316 PMCID: PMC189748 DOI: 10.1128/jvi.69.12.8027-8034.1995] [Citation(s) in RCA: 71] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023] Open
Abstract
The Epstein-Barr virus (EBV)-expressed RNA 1 (EBER1) associates tightly with the ribosomal protein L22. We determined the general requirements for an RNA to bind L22 in a SELEX experiment, selecting RNA ligands for L22 from a randomized pool of RNA sequences by using an L22-glutathione S-transferase fusion protein. The selected sequences all contained a stem-loop motif similar to that of the region of EBER1 previously shown to interact with L22. The nucleotides were highly conserved at three positions within the stem-loop and identical to the corresponding nucleotides in EBER1. Two independent binding sites for L22 could be identified in EBER1, and mobility shift assays indicated that two L22 molecules can interact with EBER1 simultaneously. To search for a cellular L22 ligand, we constructed a SELEX library from cDNA fragments derived from RNA that was coimmunoprecipitated with L22 from an EBV-negative whole-cell lysate. After four rounds of selection and amplification, most of the clones that were obtained overlapped a sequence corresponding to the stem-loop between nucleotides 302 and 317 in human 28S ribosomal RNA. This stem-loop fulfills the criteria for optimal binding to L22 that were defined by SELEX, suggesting that human 28S ribosomal RNA is likely to be a cellular L22 ligand. Additional L22 binding sites were found in 28S ribosomal RNA, as well as within 18S ribosomal RNA and in RNA segments not present in sequence databases. The methodology described for the conversion of a preselected cellular RNA pool into a SELEX library might be generally applicable to other proteins for the identification of cellular RNA ligands.
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Affiliation(s)
- M Dobbelstein
- Howard Hughes Medical Institute, Princeton University, Lewis Thomas Laboratory, New Jersey 08544-1014, USA
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31
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Ross LL, Danehower SC, Proia AD, Sontag M, Brown DM, Laurenza A, Besterman JM. Coordinated activation of corneal wound response genes in vivo as observed by in situ hybridization. Exp Eye Res 1995; 61:435-50. [PMID: 8549685 DOI: 10.1016/s0014-4835(05)80139-3] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
We used subtractive screening of a cDNA library prepared from corneoscleral rims after cauterizing rat corneas. We identified 76 clones whose corresponding mRNA increased during the wound healing process in an in vivo model of injury which damages the corneal epithelium, stroma, and endothelium. Of these clones, 31 sequences encode known proteins. Another 45 clones are novel sequences based on comparison with the GenBank/EMBL databases. Changes in the level of expression of the novel genes, and a selected number of the known genes, were examined by in situ hybridization 22 and 72 hr after corneal injury. The majority produced a 'wound pattern' of expression such that the mRNAs were highly induced in all cell types adjacent to the wound site at 22 hr post injury. This signal decreased in intensity with distance from the wound site. In a subset of corneoslceral rims examined by in situ hybridization, the mRNAs for these genes were also highly induced in the limbal epithelium, where the progenitor corneal epithelial stem cells reside. By 72 hr, when acute tissue damage had been repaired, the induced mRNA was only faintly present in the thickened epithelium. Our results provide a useful framework for further studies defining the pathophysiological roles of the known and novel proteins encoded by the isolated cDNA clones.
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Affiliation(s)
- L L Ross
- Department of Cell Biology, Glaxo Research Institute, Research Triangle Park, North Carolina 27709, USA
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32
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Lavergne JP, Reboud AM, Sontag B, Guillot D, Reboud JP. Binding of GDP to a ribosomal protein after elongation factor-2 dependent GTP hydrolysis. BIOCHIMICA ET BIOPHYSICA ACTA 1992; 1132:284-9. [PMID: 1420308 DOI: 10.1016/0167-4781(92)90162-s] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Incubation of 80S ribosomes with a substoichiometric amount of [alpha-32P]GTP and with eEF-2 resulted in the specific labeling of one ribosomal protein which migrated very close to the position of the acidic phosphoprotein P2 from the 60S subunit in two-dimensional isofocusing-SDS gel electrophoresis. Localization of protein P2 in this electrophoretic system was ascertained by correlation with its position in the standard two-dimensional acidic-SDS gel electrophoresis after its specific phosphorylation by casein kinase II. Labeling of the ribosomal protein was dependent on the presence of eEF-2, and could be attributed to [alpha-32P]GDP binding from the results of chase experiments and HPLC identification, this binding being very likely responsible for the slight shift in the electrophoretical position of the protein. Incubation of ribosomes with tRNA(Phe) in the absence of mRNA induced the release of the bound GDP.
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Affiliation(s)
- J P Lavergne
- Laboratoire de Biochimie Medicale, Université Lyon I, CNRS UPR 412, France
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33
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Naranda T, Ballesta JP. Phosphorylation controls binding of acidic proteins to the ribosome. Proc Natl Acad Sci U S A 1991; 88:10563-7. [PMID: 1961721 PMCID: PMC52969 DOI: 10.1073/pnas.88.23.10563] [Citation(s) in RCA: 26] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
The replacement of each one of the eight serine residues present in the amino acid sequence of the Saccharomyces cerevisiae acidic ribosomal phosphoprotein YP2 beta (L45) by different amino acids has been performed by heteroduplex site-directed mutagenesis in the cloned gene. The mutated DNA was used to transform a yeast strain previously deprived of the original protein YP2 beta (L45) by gene disruption. The replacement of serine in position 19 by either alanine, aspartic acid, or threonine prevents in vivo phosphorylation of the protein and its interaction with the ribosome. The serine-19 mutated gene is unable to rescue the negative effect on the growth rate caused by elimination of the original protein in YP2 beta (L45) gene disrupted strains. The mutation of any one of the other seven serine residues has no effect on either the phosphorylation or the ribosome binding capacity of the protein, although replacement of serine-72 seems to increase the sensitivity of the polypeptide to degradation. These results provide strong evidence indicating that ribosomal protein phosphorylation plays an important part in the activity of the particle and that it supports the existence of a control mechanism of protein synthesis, which would regulate the level of phosphorylation of acidic proteins.
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Affiliation(s)
- T Naranda
- Centro de Biologia Molecular, Consejo Superior de Investigaciones Científicas, Canto Blanco, Madrid, Spain
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34
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Marzouki A, Lavergne JP, Reboud JP, Reboud AM. Modification of the accessibility of ribosomal proteins after elongation factor 2 binding to rat liver ribosomes and during translocation. BIOCHIMICA ET BIOPHYSICA ACTA 1990; 1048:238-44. [PMID: 2322579 DOI: 10.1016/0167-4781(90)90062-7] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Free- and EF-2-bound 80 S ribosomes, within the high-affinity complex with the non-hydrolysable GTP analog: guanylylmethylenediphosphonate (GuoPP(CH2)P), and the low-affinity complex with GDP, were treated with trypsin under conditions that modified neither their protein synthesis ability nor their sedimentation constant nor the bound EF-2 itself. Proteins extracted from trypsin-digested ribosomes were unambiguously identified using three different two-dimensional gel electrophoresis systems and 5 S RNA release was checked by submitting directly free- and EF-2-bound 80 S ribosomes, incubated with trypsin, to two-dimensional gel electrophoresis. Our results indicate that the binding of (EF-2)-GuoPP[CH2]P to 80 S ribosomes modified the behavior of a cluster of five proteins which were trypsin-resistant within free 80 S ribosomes and trypsin-sensitive within the high-affinity complex (proteins: L3, L10, L13a, L26, L27a). As for the binding of (EF-2)-GDP to 80 S ribosomes, it induced an intermediate conformational change of ribosomes, unshielding only protein L13a and L27a. Quantitative release of free intact 5 S RNA which occurred in the first case but not in the second one, should be related to the trypsinolysis of protein(s) L3 and/or L10 and/or L26. Results were discussed in relation to structural and functional data available on the ribosomal proteins we found to be modified by EF-2 binding.
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Affiliation(s)
- A Marzouki
- Laboratoire de Biochimie Médicale, Université Claude Bernard, Villeurbanne, France
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35
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Sharp MG, Adams SM, Elvin P, Walker RA, Brammar WJ, Varley JM. A sequence previously identified as metastasis-related encodes an acidic ribosomal phosphoprotein, P2. Br J Cancer 1990; 61:83-8. [PMID: 2153399 PMCID: PMC1971331 DOI: 10.1038/bjc.1990.19] [Citation(s) in RCA: 30] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
We have used a metastasis-related human cDNA isolated from a liver metastasis from a colonic adenocarcinoma to screen a human breast carcinoma cDNA library for homologous sequences. Nucleotide sequence analysis of positive clones revealed that the cDNA represents a ribosomal phosphoprotein. P2. The expression of P2 mRNA was significantly higher (Student's t test, one tail; P less than or equal to 0.01) in seven fibroadenomas than in seven carcinomas, with an average five-fold difference. This enhanced expression level P2 mRNA in benign fibroadenomas compared with malignant carcinomas is contrary to that expected, based on earlier work with normal colonic mucosa, colorectal carcinoma and hepatic metastasis. The identification of gene transcripts which differ in abundance and correlate with the metastatic phenotype may be of considerable importance both as diagnostic aids and in defining the changes associated with tumour progression and metastasis at the molecular level. The possible role that ribosomal proteins may play in the progression of carcinoma of the breast is discussed.
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Affiliation(s)
- M G Sharp
- University/ICI Joint Laboratory, Leicester, UK
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36
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Lavergne JP, Marzouki A, Reboud JP, Reboud AM. Reconstitution of the active rat liver 60 S ribosomal subunit from different preparations of core particles and split proteins. FEBS Lett 1988; 236:345-51. [PMID: 3044828 DOI: 10.1016/0014-5793(88)80053-x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Proteins extracted from the 60 S rat liver ribosomal subunit with 50% ethanol/0.5 M K Cl produced only a partial reactivation of the corresponding core particles. In contrast, the same split proteins were able to reactivate the core particles prepared with dimethyl-maleic anhydride (DMMA) to the same level as that observed using the DMMA-split proteins, i.e. 60-80% of the control according to the catalytic activities tested. Comparative analysis of the two split protein fractions showed only four common proteins: P1-P2, which alone restored part of the activities, especially the EF-2-dependent GTPase one, and L10a, L12, which must be responsible for the additional reactivation. The poor ability of the ethanol/KCl core particles to be reactivated was shown to be probably related to a conformational alteration which destabilized the 5 S RNA-protein complex. Proteins present in the ethanol/KCl wash of Saccharomyces cerevisiae 60 S subunits were found to be partly active in subunit reconstitution using rat liver DMMA core particles.
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Affiliation(s)
- J P Lavergne
- Laboratoire de Biochimie Médicale, Université Lyon I, Villeurbanne, France
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37
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Lavergne JP, Marzouki A, Reboud JP, Reboud AM. Topography and stoichiometry of acidic phosphoproteins in rat liver 60 S ribosomal subunit. FEBS Lett 1988; 232:29-34. [PMID: 3366245 DOI: 10.1016/0014-5793(88)80380-6] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
In reconstitution experiments of active 60 S subunits from inactive core particles obtained by using dimethyl maleic anhydride (DMMA), we observed that the phosphoproteins P1-P2 were extracted from the subunit by DMMA as a complex with other proteins. This complex was separated by electrophoresis and zonal centrifugation and shown, after 125I iodination of its components, to contain L22 and S12 in addition to P1-P2. Results suggest that it contains two copies of P1-P2 for one of L22 and S12.
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Affiliation(s)
- J P Lavergne
- Laboratoire de Biochimie Médicale, Université Lyon 1, Villeurbanne, France
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