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Liu X, Geng Y, Liang J, Coelho AL, Yao C, Deng N, Wang Y, Dai K, Huang G, Xie T, Liu N, Rowan SC, Taghavifar F, Kulur V, Liu Z, Stripp BR, Hogaboam CM, Jiang D, Noble PW. HER2 drives lung fibrosis by activating a metastatic cancer signature in invasive lung fibroblasts. J Exp Med 2022; 219:e20220126. [PMID: 35980387 PMCID: PMC9391950 DOI: 10.1084/jem.20220126] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2022] [Revised: 04/29/2022] [Accepted: 07/14/2022] [Indexed: 12/03/2022] Open
Abstract
Progressive tissue fibrosis, including idiopathic pulmonary fibrosis (IPF), is characterized by excessive recruitment of fibroblasts to sites of tissue injury and unremitting extracellular matrix deposition associated with severe morbidity and mortality. However, the molecular mechanisms that control progressive IPF have yet to be fully determined. Previous studies suggested that invasive fibroblasts drive disease progression in IPF. Here, we report profiling of invasive and noninvasive fibroblasts from IPF patients and healthy donors. Pathway analysis revealed that the activated signatures of the invasive fibroblasts, the top of which was ERBB2 (HER2), showed great similarities to those of metastatic lung adenocarcinoma cancer cells. Activation of HER2 in normal lung fibroblasts led to a more invasive genetic program and worsened fibroblast invasion and lung fibrosis, while antagonizing HER2 signaling blunted fibroblast invasion and ameliorated lung fibrosis. These findings suggest that HER2 signaling may be a key driver of fibroblast invasion and serve as an attractive target for therapeutic intervention in IPF.
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Affiliation(s)
- Xue Liu
- Department of Medicine and Women’s Guild Lung Institute, Cedars-Sinai Medical Center, Los Angeles, CA
| | - Yan Geng
- Department of Medicine and Women’s Guild Lung Institute, Cedars-Sinai Medical Center, Los Angeles, CA
- School of Pharmaceutical Science, Jiangnan University, Wuxi, Jiangsu, China
| | - Jiurong Liang
- Department of Medicine and Women’s Guild Lung Institute, Cedars-Sinai Medical Center, Los Angeles, CA
| | - Ana Lucia Coelho
- Department of Medicine and Women’s Guild Lung Institute, Cedars-Sinai Medical Center, Los Angeles, CA
| | - Changfu Yao
- Department of Medicine and Women’s Guild Lung Institute, Cedars-Sinai Medical Center, Los Angeles, CA
| | - Nan Deng
- Biostatistics and Bioinformatics Research Center and Samuel Oschin Comprehensive Cancer Institute, Los Angeles, CA
| | - Yizhou Wang
- Genomics Core, Cedars-Sinai Medical Center, Los Angeles, CA
| | - Kristy Dai
- Department of Medicine and Women’s Guild Lung Institute, Cedars-Sinai Medical Center, Los Angeles, CA
| | - Guanling Huang
- Department of Medicine and Women’s Guild Lung Institute, Cedars-Sinai Medical Center, Los Angeles, CA
| | - Ting Xie
- Department of Medicine and Women’s Guild Lung Institute, Cedars-Sinai Medical Center, Los Angeles, CA
| | - Ningshan Liu
- Department of Medicine and Women’s Guild Lung Institute, Cedars-Sinai Medical Center, Los Angeles, CA
| | - Simon C. Rowan
- Department of Medicine and Women’s Guild Lung Institute, Cedars-Sinai Medical Center, Los Angeles, CA
| | - Forough Taghavifar
- Department of Medicine and Women’s Guild Lung Institute, Cedars-Sinai Medical Center, Los Angeles, CA
| | - Vrishika Kulur
- Department of Medicine and Women’s Guild Lung Institute, Cedars-Sinai Medical Center, Los Angeles, CA
| | - Zhenqiu Liu
- Biostatistics and Bioinformatics Research Center and Samuel Oschin Comprehensive Cancer Institute, Los Angeles, CA
| | - Barry R. Stripp
- Department of Medicine and Women’s Guild Lung Institute, Cedars-Sinai Medical Center, Los Angeles, CA
| | - Cory M. Hogaboam
- Department of Medicine and Women’s Guild Lung Institute, Cedars-Sinai Medical Center, Los Angeles, CA
| | - Dianhua Jiang
- Department of Medicine and Women’s Guild Lung Institute, Cedars-Sinai Medical Center, Los Angeles, CA
- Department of Biomedical Sciences, Cedars-Sinai Medical Center, Los Angeles, CA
| | - Paul W. Noble
- Department of Medicine and Women’s Guild Lung Institute, Cedars-Sinai Medical Center, Los Angeles, CA
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Li Q, Jiang Y, Song N, Zhou B, Li Z, Lin L. An Immune-Related Genetic Feature Depicted the Heterogeneous Nature of Lung Adenocarcinoma and Squamous Cell Carcinoma and Their Distinctive Predicted Drug Responses. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2022; 2022:8447083. [PMID: 36071867 PMCID: PMC9442502 DOI: 10.1155/2022/8447083] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/20/2022] [Revised: 08/08/2022] [Accepted: 08/10/2022] [Indexed: 11/29/2022]
Abstract
One of the primary causes of global cancer-associated mortality is lung cancer (LC). Current improvements in the management of LC rely mainly on the advancement of patient stratification, both molecularly and clinically, to achieve the maximal therapeutic benefit, while most LC screening protocols remain underdeveloped. In this research, we first employed two algorithms (ESTIMATE and xCell) to calculate the immune/stromal infiltration scores. This helped identify the altered immune infiltration landscapes in lung adenocarcinoma (LUAD) and squamous cell carcinoma (LUSC). Afterward, based on their immune-related characteristics, we successfully stratified the LUAD and LUSC into 2 and 3 clusters, respectively. Different from the conventional bioinformatic approaches that start from the investigation of differential expression of single genes, differentially enriched curated gene sets identified through gene set variation analyses (GSVA) were curated, and gene names were reconstructed afterward. Furthermore, weighted gene correlation network analyses (WGCNA) were used to reveal hub genes highly connected with the clustering process. Actual expression levels of critical hub genes among different clusters were compared and so were the functional pathways these genes enriched into. Lastly, a computational method was applied to predict and compare the responses of each cluster to primary therapeutic agents. The heterogeneity presented in our study, along with the drug responses expected for identified clusters, may shed light on future exploration of combination immunochemotherapy that facilitates the optimization of individualized therapy.
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Affiliation(s)
- Qiuyuan Li
- Department of Thoracic Surgery, Tongji University Shanghai Pulmonary Hospital, No. 507 Zhengmin Rd., Shanghai, China
| | - Yan Jiang
- Department of Thoracic Surgery, Tongji University Shanghai Pulmonary Hospital, No. 507 Zhengmin Rd., Shanghai, China
| | - Nan Song
- Department of Thoracic Surgery, Tongji University Shanghai Pulmonary Hospital, No. 507 Zhengmin Rd., Shanghai, China
| | - Bin Zhou
- Department of Thoracic Surgery, Tongji University Shanghai Pulmonary Hospital, No. 507 Zhengmin Rd., Shanghai, China
| | - Zhao Li
- Department of Thoracic Surgery, Tongji University Shanghai Pulmonary Hospital, No. 507 Zhengmin Rd., Shanghai, China
| | - Lei Lin
- Department of Thoracic Surgery, Tongji University Shanghai Pulmonary Hospital, No. 507 Zhengmin Rd., Shanghai, China
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Lee DS, Song Y, Lee YG, Bae HJ. Comparative Evaluation of Adsorption of Major Enzymes in a Cellulase Cocktail Obtained from Trichoderma reesei onto Different Types of Lignin. Polymers (Basel) 2022; 14:polym14010167. [PMID: 35012188 PMCID: PMC8747337 DOI: 10.3390/polym14010167] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2021] [Revised: 12/22/2021] [Accepted: 12/29/2021] [Indexed: 02/04/2023] Open
Abstract
Cellulase adsorption onto lignin decreases the productivity of enzymatic hydrolysis of lignocellulosic biomass. Here, adsorption of enzymes onto different types of lignin was investigated, and the five major enzymes—cellobiohydrolases (CBHs), endoglucanase (Cel7B), β-glucosidase (Cel3A), xylanase (XYNIV), and mannanase (Man5A)—in a cellulase cocktail obtained from Trichoderma reesei were individually analyzed through SDS-PAGE and zymogram assay. Lignin was isolated from woody (oak and pine lignin) and herbaceous (rice straw and kenaf lignin) plants. The relative adsorption of CBHs compared to the control was in the range of 14.15–18.61%. The carbohydrate binding motif (CBM) of the CBHs contributed to higher adsorption levels in oak and kenaf lignin, compared to those in pine and rice lignin. The adsorption of endoglucanase (Cel7B) by herbaceous plant lignin was two times higher than that of woody lignin, whereas XYNIV showed the opposite pattern. β-glucosidase (Cel3A) displayed the highest and lowest adsorption ratios on rice straw and kenaf lignin, respectively. Mannanase (Man5A) was found to have the lowest adsorption ratio on pine lignin. Our results showed that the hydrophobic properties of CBM and the enzyme structures are key factors in adsorption onto lignin, whereas the properties of specific lignin types indirectly affect adsorption.
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Affiliation(s)
- Dae-Seok Lee
- Bio-Energy Research Center, Chonnam National University, Gwangju 500-575, Korea; (D.-S.L.); (Y.S.)
| | - Younho Song
- Bio-Energy Research Center, Chonnam National University, Gwangju 500-575, Korea; (D.-S.L.); (Y.S.)
| | - Yoon-Gyo Lee
- Department of Wood Science and Landscape Architecture, Chonnam National University, Gwangju 500-757, Korea;
| | - Hyeun-Jong Bae
- Bio-Energy Research Center, Chonnam National University, Gwangju 500-575, Korea; (D.-S.L.); (Y.S.)
- Department of Bioenergy Science and Technology, College of Agriculture and Life Sciences, Chonnam National University, Gwangju 500-757, Korea
- Correspondence: ; Tel.: +81-62-530-2097
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Ta HDK, Wang WJ, Phan NN, An Ton NT, Anuraga G, Ku SC, Wu YF, Wang CY, Lee KH. Potential Therapeutic and Prognostic Values of LSM Family Genes in Breast Cancer. Cancers (Basel) 2021; 13:4902. [PMID: 34638387 PMCID: PMC8508234 DOI: 10.3390/cancers13194902] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2021] [Revised: 09/24/2021] [Accepted: 09/26/2021] [Indexed: 12/26/2022] Open
Abstract
In recent decades, breast cancer (BRCA) has become one of the most common diseases worldwide. Understanding crucial genes and their signaling pathways remain an enormous challenge in evaluating the prognosis and possible therapeutics. The "Like-Smith" (LSM) family is known as protein-coding genes, and its member play pivotal roles in the progression of several malignancies, although their roles in BRCA are less clear. To discover biological processes associated with LSM family genes in BRCA development, high-throughput techniques were applied to clarify expression levels of LSMs in The Cancer Genome Atlas (TCGA)-BRCA dataset, which was integrated with the cBioPortal database. Furthermore, we investigated prognostic values of LSM family genes in BCRA patients using the Kaplan-Meier database. Among genes of this family, LSM4 expression levels were highly associated with poor prognostic outcomes with a hazard ratio of 1.35 (95% confidence interval 1.21-1.51, p for trend = 3.4 × 10-7). MetaCore and GlueGo analyses were also conducted to examine transcript expression signatures of LSM family members and their coexpressed genes, together with their associated signaling pathways, such as "Cell cycle role of APC in cell cycle regulation" and "Immune response IL-15 signaling via MAPK and PI3K cascade" in BRCA. Results showed that LSM family members, specifically LSM4, were significantly correlated with oncogenesis in BRCA patients. In summary, our results suggested that LSM4 could be a prospective prognosticator of BRCA.
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Affiliation(s)
- Hoang Dang Khoa Ta
- PhD Program for Cancer Molecular Biology and Drug Discovery, College of Medical Science and Technology, Taipei Medical University and Academia Sinica, Taipei 11031, Taiwan; (H.D.K.T.); (G.A.)
- Graduate Institute of Cancer Biology and Drug Discovery, College of Medical Science and Technology, Taipei Medical University, Taipei 11031, Taiwan;
| | - Wei-Jan Wang
- Department of Biological Science and Technology, Research Center for Cancer Biology, China Medical University, Taichung 40402, Taiwan;
| | - Nam Nhut Phan
- Institute for Environmental Science, Nguyen Tat Thanh University, Ho Chi Minh City 700000, Vietnam;
| | - Nu Thuy An Ton
- NTT Institute of Hi-Technology, Nguyen Tat Thanh University, Ho Chi Minh City 700000, Vietnam;
| | - Gangga Anuraga
- PhD Program for Cancer Molecular Biology and Drug Discovery, College of Medical Science and Technology, Taipei Medical University and Academia Sinica, Taipei 11031, Taiwan; (H.D.K.T.); (G.A.)
- Graduate Institute of Cancer Biology and Drug Discovery, College of Medical Science and Technology, Taipei Medical University, Taipei 11031, Taiwan;
- Department of Statistics, Faculty of Science and Technology, Universitas PGRI Adi Buana, Surabaya 60234, Indonesia
| | - Su-Chi Ku
- Graduate Institute of Cancer Biology and Drug Discovery, College of Medical Science and Technology, Taipei Medical University, Taipei 11031, Taiwan;
| | - Yung-Fu Wu
- National Defense Medical Center, Department of Medical Research, School of Medicine, Tri-Service General Hospital, Taipei 11490, Taiwan;
| | - Chih-Yang Wang
- PhD Program for Cancer Molecular Biology and Drug Discovery, College of Medical Science and Technology, Taipei Medical University and Academia Sinica, Taipei 11031, Taiwan; (H.D.K.T.); (G.A.)
- Graduate Institute of Cancer Biology and Drug Discovery, College of Medical Science and Technology, Taipei Medical University, Taipei 11031, Taiwan;
| | - Kuen-Haur Lee
- PhD Program for Cancer Molecular Biology and Drug Discovery, College of Medical Science and Technology, Taipei Medical University and Academia Sinica, Taipei 11031, Taiwan; (H.D.K.T.); (G.A.)
- Graduate Institute of Cancer Biology and Drug Discovery, College of Medical Science and Technology, Taipei Medical University, Taipei 11031, Taiwan;
- Cancer Center, Wan Fang Hospital, Taipei Medical University, Taipei 11031, Taiwan
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5
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Garcia P, Harrod A, Jha S, Jenkins J, Barnhill A, Lee H, Thompson M, Williams JP, Barefield J, Mckinnon A, Suarez P, Shah A, Lowrey AJ, Bentz GL. Effects of targeting sumoylation processes during latent and induced Epstein-Barr virus infections using the small molecule inhibitor ML-792. Antiviral Res 2021; 188:105038. [PMID: 33577806 DOI: 10.1016/j.antiviral.2021.105038] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2020] [Revised: 02/02/2021] [Accepted: 02/05/2021] [Indexed: 12/12/2022]
Abstract
As the second leading cause of death in the United States, cancer has a considerable impact on society, and one cellular process that is commonly dysregulated in many cancers is the post-translational modification of proteins by the Small Ubiquitin-like Modifier (SUMO; sumoylation). We documented that sumoylation processes are up-regulated in lymphoma tissues in the presence of Latent Membrane Protein-1 (LMP1), the principal oncoprotein of Epstein-Barr virus (EBV). LMP1-mediated dysregulation of cellular sumoylation processes contributes to oncogenesis, modulates innate immune responses, and aids the maintenance of viral latency. Manipulation of protein sumoylation has been proposed for anti-cancer and anti-viral therapies; however, known inhibitors of sumoylation do not only target sumoylation processes. Recently, a specific and selective small-molecule inhibitor of sumoylation (ML-792) was identified; however, nothing is known about the effect of ML-792 on LMP1-mediated dysregulation of cellular sumoylation or the EBV life-cycle. We hypothesized that ML-792 modulates viral replication and the oncogenic potential of EBV LMP1 by inhibiting protein sumoylation. Results showed that ML-792 inhibited sumoylation processes in multiple EBV-positive B cell lines and EBV-positive nasopharyngeal carcinoma cell lines but not in their EBV-negative counterparts. Focusing on its effect on B cells, ML-792 inhibited B-cell growth and promoted cell death at very low doses. ML-792 also modulated LMP1-induced cell migration and cell adhesion, which suggests the abrogation of the oncogenic potential of LMP1. Finally, while higher concentrations of ML-792 were sufficient to induce low levels EBV spontaneous reactivation, they decreased the production of new infectious virus following an induced reactivation and the infection of new cells, suggesting that ML-792 has anti-viral potential. Together, these findings suggest that ML-792 may be a potential therapeutic drug to treat EBV-associated lymphoid malignancies by targeting oncogenesis and the EBV life-cycle.
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Affiliation(s)
- Peter Garcia
- Division of Biomedical Sciences, Mercer University School of Medicine, Macon, GA, USA
| | - Abigail Harrod
- Division of Biomedical Sciences, Mercer University School of Medicine, Macon, GA, USA
| | - Shruti Jha
- Division of Biomedical Sciences, Mercer University School of Medicine, Macon, GA, USA
| | - Jessica Jenkins
- Division of Biomedical Sciences, Mercer University School of Medicine, Macon, GA, USA
| | - Alex Barnhill
- Division of Biomedical Sciences, Mercer University School of Medicine, Macon, GA, USA
| | - Holden Lee
- Division of Biomedical Sciences, Mercer University School of Medicine, Macon, GA, USA
| | - Merritt Thompson
- Division of Biomedical Sciences, Mercer University School of Medicine, Macon, GA, USA
| | | | - James Barefield
- Division of Biomedical Sciences, Mercer University School of Medicine, Macon, GA, USA
| | - Ashton Mckinnon
- Division of Biomedical Sciences, Mercer University School of Medicine, Macon, GA, USA
| | - Persia Suarez
- Division of Biomedical Sciences, Mercer University School of Medicine, Macon, GA, USA
| | - Ananya Shah
- Division of Biomedical Sciences, Mercer University School of Medicine, Macon, GA, USA
| | - Angela J Lowrey
- Division of Biomedical Sciences, Mercer University School of Medicine, Macon, GA, USA
| | - Gretchen L Bentz
- Division of Biomedical Sciences, Mercer University School of Medicine, Macon, GA, USA.
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Voutsadakis IA. Amplification of 8p11.23 in cancers and the role of amplicon genes. Life Sci 2020; 264:118729. [PMID: 33166592 DOI: 10.1016/j.lfs.2020.118729] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2020] [Revised: 10/31/2020] [Accepted: 11/04/2020] [Indexed: 02/08/2023]
Abstract
Copy number alterations are widespread in cancer genomes and are part of the genomic instability underlying the pathogenesis of neoplastic diseases. Recurrent copy number alterations of specific chromosomal loci may result in gains of oncogenes or losses of tumor suppressor genes and become entrenched in the genomic framework of certain types of cancers. The locus at chromosome 8p11.23 presents recurrent amplifications most commonly in squamous lung carcinomas, breast cancers, squamous esophageal carcinomas, and urothelial carcinomas. Amplification is rare in other cancers. The amplified segment involves several described oncogenes that may promote cancer cell survival and proliferation, as well as less well characterized genes that could also contribute to neoplastic processes. Genes proposed to be "drivers" in 8p11.23 amplifications include ZNF703, FGFR1 and PLPP5. Additional genes in the locus that could be functionally important in neoplastic networks include co-chaperone BAG4, lysine methyltransferase NSD3, ASH2L, a member of another methyltransferase complex, MLL and the mRNA processing and translation regulators LSM1 and EIF4EBP1. In this paper, genes located in the amplified segment of 8p11.23 will be examined for their role in cancer and data arguing for their importance for cancers with the amplification will be presented.
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Affiliation(s)
- Ioannis A Voutsadakis
- Algoma District Cancer Program, Sault Area Hospital, Sault Ste. Marie, Ontario, Canada; Section of Internal Medicine, Division of Clinical Sciences, Northern Ontario School of Medicine, Sudbury, Ontario, Canada.
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Catalá R, Carrasco-López C, Perea-Resa C, Hernández-Verdeja T, Salinas J. Emerging Roles of LSM Complexes in Posttranscriptional Regulation of Plant Response to Abiotic Stress. FRONTIERS IN PLANT SCIENCE 2019; 10:167. [PMID: 30873189 PMCID: PMC6401655 DOI: 10.3389/fpls.2019.00167] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/08/2018] [Accepted: 01/31/2019] [Indexed: 05/04/2023]
Abstract
It has long been assumed that the wide reprogramming of gene expression that modulates plant response to unfavorable environmental conditions is mainly controlled at the transcriptional level. A growing body of evidence, however, indicates that posttranscriptional regulatory mechanisms also play a relevant role in this control. Thus, the LSMs, a family of proteins involved in mRNA metabolism highly conserved in eukaryotes, have emerged as prominent regulators of plant tolerance to abiotic stress. Arabidopsis contains two main LSM ring-shaped heteroheptameric complexes, LSM1-7 and LSM2-8, with different subcellular localization and function. The LSM1-7 ring is part of the cytoplasmic decapping complex that regulates mRNA stability. On the other hand, the LSM2-8 complex accumulates in the nucleus to ensure appropriate levels of U6 snRNA and, therefore, correct pre-mRNA splicing. Recent studies reported unexpected results that led to a fundamental change in the assumed consideration that LSM complexes are mere components of the mRNA decapping and splicing cellular machineries. Indeed, these data have demonstrated that LSM1-7 and LSM2-8 rings operate in Arabidopsis by selecting specific RNA targets, depending on the environmental conditions. This specificity allows them to actively imposing particular gene expression patterns that fine-tune plant responses to abiotic stresses. In this review, we will summarize current and past knowledge on the role of LSM rings in modulating plant physiology, with special focus on their function in abiotic stress responses.
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8
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RNA-binding proteins with prion-like domains in health and disease. Biochem J 2017; 474:1417-1438. [PMID: 28389532 DOI: 10.1042/bcj20160499] [Citation(s) in RCA: 293] [Impact Index Per Article: 41.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2017] [Revised: 02/06/2017] [Accepted: 02/09/2017] [Indexed: 02/07/2023]
Abstract
Approximately 70 human RNA-binding proteins (RBPs) contain a prion-like domain (PrLD). PrLDs are low-complexity domains that possess a similar amino acid composition to prion domains in yeast, which enable several proteins, including Sup35 and Rnq1, to form infectious conformers, termed prions. In humans, PrLDs contribute to RBP function and enable RBPs to undergo liquid-liquid phase transitions that underlie the biogenesis of various membraneless organelles. However, this activity appears to render RBPs prone to misfolding and aggregation connected to neurodegenerative disease. Indeed, numerous RBPs with PrLDs, including TDP-43 (transactivation response element DNA-binding protein 43), FUS (fused in sarcoma), TAF15 (TATA-binding protein-associated factor 15), EWSR1 (Ewing sarcoma breakpoint region 1), and heterogeneous nuclear ribonucleoproteins A1 and A2 (hnRNPA1 and hnRNPA2), have now been connected via pathology and genetics to the etiology of several neurodegenerative diseases, including amyotrophic lateral sclerosis, frontotemporal dementia, and multisystem proteinopathy. Here, we review the physiological and pathological roles of the most prominent RBPs with PrLDs. We also highlight the potential of protein disaggregases, including Hsp104, as a therapeutic strategy to combat the aberrant phase transitions of RBPs with PrLDs that likely underpin neurodegeneration.
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Muppavarapu M, Huch S, Nissan T. The cytoplasmic mRNA degradation factor Pat1 is required for rRNA processing. RNA Biol 2016; 13:455-65. [PMID: 26918764 DOI: 10.1080/15476286.2016.1154253] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
Pat1 is a key cytoplasmic mRNA degradation factor, the loss of which severely increases mRNA half-lives. Several recent studies have shown that Pat1 can enter the nucleus and can shuttle between the nucleus and the cytoplasm. As a result, many nuclear roles have been proposed for Pat1. In this study, we analyzed four previously suggested nuclear roles of Pat1 and show that Pat1 is not required for efficient pre-mRNA splicing or pre-mRNA decay in yeast. However, lack of Pat1 results in accumulation of pre-rRNA processing intermediates. Intriguingly, we identified a novel genetic relationship between Pat1 and the rRNA decay machinery, specifically the exosome and the TRAMP complex. While the pre-rRNA processing intermediates that accumulate in the pat1 deletion mutant are, at least to some extent, recognized as aberrant by the rRNA degradation machinery, it is unlikely that these accumulations are the cause of their synthetic sick relationship. Here, we show that the dysregulation of the levels of mRNAs related to ribosome biogenesis could be the cause of the accumulation of the pre-rRNA processing intermediates. Although our results support a role for Pat1 in transcription, they nevertheless suggest that the primary cause of the dysregulated mRNA levels is most likely due to Pat1's role in mRNA decapping and mRNA degradation.
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Affiliation(s)
- Mridula Muppavarapu
- a Department of Molecular Biology , Umeå University , SE-901 87 Umeå , Sweden
| | - Susanne Huch
- a Department of Molecular Biology , Umeå University , SE-901 87 Umeå , Sweden
| | - Tracy Nissan
- a Department of Molecular Biology , Umeå University , SE-901 87 Umeå , Sweden
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Lakschevitz FS, Visser MB, Sun C, Glogauer M. Neutrophil transcriptional profile changes during transit from bone marrow to sites of inflammation. Cell Mol Immunol 2014; 12:53-65. [PMID: 24909740 DOI: 10.1038/cmi.2014.37] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2013] [Revised: 05/02/2014] [Accepted: 05/02/2014] [Indexed: 01/13/2023] Open
Abstract
It has recently been established that neutrophils, the most abundant leukocytes, are capable of changes in gene expression during inflammatory responses. However, changes in the transcriptome as the neutrophil leaves the bone marrow have yet to be described. We hypothesized that neutrophils are transcriptionally active cells that alter their gene expression profiles as they migrate into the vasculature and then into inflamed tissues. Our goal was to provide an overview of how the neutrophil's transcriptome changes as they migrate through different compartments using microarray and bio-informatic approaches. Our study demonstrates that neutrophils are highly plastic cells where normal environmental cues result in a site-specific neutrophil transcriptome. We demonstrate that neutrophil genes undergo one of four distinct expression change patterns as they move from bone marrow through the circulation to sites of inflammation: (i) continuously increasing; (ii) continuously decreasing; (iii) a down-up-down; and (iv) an up-down-up pattern. Additionally, we demonstrate that the neutrophil migration signaling network and the balance between anti-apoptotic and pro-apoptotic signaling are two of the main regulatory mechanisms that change as the neutrophil transits through compartments.
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Affiliation(s)
- Flavia S Lakschevitz
- 1] Department of Periodontology, Faculty of Dentistry, University of Toronto, Toronto, Ont., Canada [2] Matrix Dynamics Group, Faculty of Dentistry, University of Toronto, Toronto, Ont., Canada
| | - Michelle B Visser
- 1] Matrix Dynamics Group, Faculty of Dentistry, University of Toronto, Toronto, Ont., Canada [2] Current address: Department of Oral Biology, School of Dental Medicine, University at Buffalo, The State University of New York, Buffalo, NY, USA
| | - Chunxiang Sun
- Matrix Dynamics Group, Faculty of Dentistry, University of Toronto, Toronto, Ont., Canada
| | - Michael Glogauer
- 1] Department of Periodontology, Faculty of Dentistry, University of Toronto, Toronto, Ont., Canada [2] Matrix Dynamics Group, Faculty of Dentistry, University of Toronto, Toronto, Ont., Canada
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Pu LJ, Lu L, Zhang RY, Du R, Shen Y, Zhang Q, Yang ZK, Chen QJ, Shen WF. Glycation of apoprotein A-I is associated with coronary artery plaque progression in type 2 diabetic patients. Diabetes Care 2013; 36:1312-20. [PMID: 23230102 PMCID: PMC3631856 DOI: 10.2337/dc12-1411] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
OBJECTIVE To investigate whether glycation level of apoprotein (apo)A-I is associated with coronary artery disease (CAD) and plaque progression in patients with type 2 diabetes. RESEARCH DESIGN AND METHODS Among 375 consecutive type 2 diabetic patients undergoing quantitative coronary angiography (QCA) and intravascular ultrasound (IVUS), 82 patients with nonsignificant stenosis (luminal diameter narrowing <30% [group I]) and 190 patients with significant CAD (luminal diameter stenosis ≥70% [group II]) were included for analysis of apoA-I glycation level and serum activity of lecithin: cholesterol acyltransferase (LCAT). The control group had 136 healthy subjects. At the 1-year follow-up, angiography and IVUS were repeated mainly in group II patients for plaque progression assessment. RESULTS Relative intensity of apoA-I glycation by densitometry was increased, and serum LCAT activity was decreased stepwise across groups control, I, and II. These two measurements were associated with the number of diseased coronary arteries and extent index in group II. During 1-year follow-up, QCA detected 45 patients with plaque progression in 159 subjects, and IVUS found 38 patients with plaque progression in 127 subjects. Baseline relative intensity of apoA-I glycation was significantly increased in patients with plaque progression compared with those without, with values associated with changes in QCA and IVUS measurements. Multivariable regression analysis revealed that baseline relative intensity of apoA-I glycation was an independent determinant of CAD and plaque progression in type 2 diabetic patients. CONCLUSIONS ApoA-I glycation level is associated with the severity of CAD and coronary artery plaque progression in type 2 diabetic patients.
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Affiliation(s)
- Li Jin Pu
- Department of Cardiology, Shanghai Rui Jin Hospital, Shanghai, People’s Republic of China
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12
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Potassium aspartate attenuates apoptotic cell death after focal cerebral ischemia in rats. ACTA ACUST UNITED AC 2013. [DOI: 10.1016/j.biomag.2012.11.002] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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13
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Abstract
All RNA species in yeast cells are subject to turnover. Work over the past 20 years has defined degradation mechanisms for messenger RNAs, transfer RNAs, ribosomal RNAs, and noncoding RNAs. In addition, numerous quality control mechanisms that target aberrant RNAs have been identified. Generally, each decay mechanism contains factors that funnel RNA substrates to abundant exo- and/or endonucleases. Key issues for future work include determining the mechanisms that control the specificity of RNA degradation and how RNA degradation processes interact with translation, RNA transport, and other cellular processes.
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Affiliation(s)
- Roy Parker
- Department of Molecular and Cellular Biology, University of Arizona and Howard Hughes Medical Institute, Tucson, AZ 85721, USA.
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14
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Gold-nanobeacons for real-time monitoring of RNA synthesis. Biosens Bioelectron 2012; 36:161-7. [DOI: 10.1016/j.bios.2012.04.006] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2012] [Revised: 03/20/2012] [Accepted: 04/09/2012] [Indexed: 12/20/2022]
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15
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Neelakanta G, Hudson AM, Sultana H, Cooley L, Fikrig E. Expression of Ixodes scapularis antifreeze glycoprotein enhances cold tolerance in Drosophila melanogaster. PLoS One 2012; 7:e33447. [PMID: 22428051 PMCID: PMC3302814 DOI: 10.1371/journal.pone.0033447] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2011] [Accepted: 02/09/2012] [Indexed: 11/23/2022] Open
Abstract
Drosophila melanogaster experience cold shock injury and die when exposed to low non-freezing temperatures. In this study, we generated transgenic D. melanogaster that express putative Ixodes scapularis antifreeze glycoprotein (IAFGP) and show that the presence of IAFGP increases the ability of flies to survive in the cold. Male and female adult iafgp-expressing D. melanogaster exhibited higher survival rates compared with controls when placed at non-freezing temperatures. Increased hatching rates were evident in embryos expressing IAFGP when exposed to the cold. The TUNEL assay showed that flight muscles from iafgp-expressing female adult flies exhibited less apoptotic damage upon exposure to non-freezing temperatures in comparison to control flies. Collectively, these data suggest that expression of iafgp increases cold tolerance in flies by preventing apoptosis. This study defines a molecular basis for the role of an antifreeze protein in cryoprotection of flies.
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Affiliation(s)
- Girish Neelakanta
- Section of Infectious Diseases, Department of Internal Medicine, Yale University School of Medicine, New Haven, Connecticut, United States of America
| | - Andrew M. Hudson
- Department of Genetics, Yale University School of Medicine, New Haven, Connecticut, United States of America
| | - Hameeda Sultana
- Section of Infectious Diseases, Department of Internal Medicine, Yale University School of Medicine, New Haven, Connecticut, United States of America
| | - Lynn Cooley
- Department of Genetics, Yale University School of Medicine, New Haven, Connecticut, United States of America
- Department of Cell Biology, Yale University School of Medicine, New Haven, Connecticut, United States of America
- Department of Molecular, Cellular, and Developmental Biology, Yale University School of Medicine, New Haven, Connecticut, United States of America
| | - Erol Fikrig
- Section of Infectious Diseases, Department of Internal Medicine, Yale University School of Medicine, New Haven, Connecticut, United States of America
- Howard Hughes Medical Institute, Chevy Chase, Maryland, United States of America
- * E-mail:
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16
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Maraia RJ, Lamichhane TN. 3' processing of eukaryotic precursor tRNAs. WILEY INTERDISCIPLINARY REVIEWS-RNA 2012; 2:362-75. [PMID: 21572561 DOI: 10.1002/wrna.64] [Citation(s) in RCA: 97] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
Biogenesis of eukaryotic tRNAs requires transcription by RNA polymerase III and subsequent processing. 5' processing of precursor tRNA occurs by a single mechanism, cleavage by RNase P, and usually occurs before 3' processing although some conditions allow observation of the 3'-first pathway. 3' processing is relatively complex and is the focus of this review. Precursor RNA 3'-end formation begins with pol III termination generating a variable length 3'-oligo(U) tract that represents an underappreciated and previously unreviewed determinant of processing. Evidence that the pol III-intrinsic 3'exonuclease activity mediated by Rpc11p affects 3'oligo(U) length is reviewed. In addition to multiple 3' nucleases, precursor tRNA(pre-tRNA) processing involves La and Lsm, distinct oligo(U)-binding proteins with proposed chaperone activities. 3' processing is performed by the endonuclease RNase Z or the exonuclease Rex1p (possibly others) along alternate pathways conditional on La. We review a Schizosaccharomyces pombe tRNA reporter system that has been used to distinguish two chaperone activities of La protein to its two conserved RNA binding motifs. Pre-tRNAs with structural impairments are degraded by a nuclear surveillance system that mediates polyadenylation by the TRAMP complex followed by 3'-digestion by the nuclear exosome which appears to compete with 3' processing. We also try to reconcile limited data on pre-tRNA processing and Lsm proteins which largely affect precursors but not mature tRNAs.A pathway is proposed in which 3' oligo(U) length is a primary determinant of La binding with subsequent steps distinguished by 3'-endo versus exo nucleases,chaperone activities, and nuclear surveillance.
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Affiliation(s)
- Richard J Maraia
- Intramural Research Program, Eunice Kennedy Shriver NationalInstitute of Child Health and Human Development, NationalInstitutes of Health, Bethesda, MD, USA.
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17
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Dengue hemorrhagic fever-associated immunomediators induced via maturation of dengue virus nonstructural 4B protein in monocytes modulate endothelial cell adhesion molecules and human microvascular endothelial cells permeability. Virology 2011; 422:326-37. [PMID: 22129847 DOI: 10.1016/j.virol.2011.10.030] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2011] [Revised: 10/07/2011] [Accepted: 10/31/2011] [Indexed: 11/21/2022]
Abstract
We previously demonstrated that dengue virus (DENV) nonstructural 4B protein (NS4B) induced dengue hemorrhagic fever (DHF)-associated immunomediators in THP-1 monocytes. Moreover, cleavage of NS4AB polyprotein by the NS2B3 protease, significantly increased immunomediator production to levels found after DENV infection. In this report using primary human microvascular endothelial cells (HMVEC) transwell permeability model and HMVEC monolayer, we demonstrate that the immunomediators secreted in the supernatants of DENV-infected monocytes increase HMVEC permeability and expression of ICAM-1, VCAM-1 and E-selectin. Moreover, maturation of NS4B via cleavage of 2KNS4B is sufficient to induce immunomediators that cause HMVEC phenotypic changes, which appear to be synergistically induced by TNFα and IL-8. These data suggest that therapies targeting the maturation steps of NS4B, particularly 2KNS4B processing, may reduce overall DHF-associated immunomediator levels, thereby reducing DHF-associated morbidity and mortality. Alternatively, TNFα inhibitors may be a valid intervention strategy during the later stages of infection to prevent DHF progression.
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18
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Mund M, Neu A, Ullmann J, Neu U, Sprangers R. Structure of the LSm657 complex: an assembly intermediate of the LSm1-7 and LSm2-8 rings. J Mol Biol 2011; 414:165-76. [PMID: 22001694 DOI: 10.1016/j.jmb.2011.09.051] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2011] [Revised: 09/23/2011] [Accepted: 09/29/2011] [Indexed: 10/16/2022]
Abstract
The nuclear LSm2-8 (like Sm) complex and the cytoplasmic LSm1-7 complex play a central role in mRNA splicing and degradation, respectively. The LSm proteins are related to the spliceosomal Sm proteins that form a heteroheptameric ring around small nuclear RNA. The assembly process of the heptameric Sm complex is well established and involves several smaller Sm assembly intermediates. The assembly of the LSm complex, however, is less well studied. Here, we solved the 2.5 Å-resolution structure of the LSm assembly intermediate that contains LSm5, LSm6, and LSm7. The three monomers display the canonical Sm fold and arrange into a hexameric LSm657-657 ring. We show that the order of the LSm proteins within the ring is consistent with the order of the related SmE, SmF, and SmG proteins in the heptameric Sm ring. Nonetheless, differences in RNA binding pockets prevent the prediction of the nucleotide binding preferences of the LSm complexes. Using high-resolution NMR spectroscopy, we confirm that LSm5, LSm6, and LSm7 also assemble into a 60-kDa hexameric ring in solution. With a combination of pull-down and NMR experiments, we show that the LSm657 complex can incorporate LSm23 in order to assemble further towards native LSm rings. Interestingly, we find that the NMR spectra of the LSm57, LSm657-657, and LSm23-657 complexes differ significantly, suggesting that the angles between the LSm building blocks change depending on the ring size of the complex. In summary, our results identify LSm657 as a plastic and functional building block on the assembly route towards the LSm1-7 and LSm2-8 complexes.
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Affiliation(s)
- Markus Mund
- Max Planck Institute for Developmental Biology, Spemannstrasse 35, D-72076 Tuebingen, Germany
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19
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Kelley JF, Kaufusi PH, Volper EM, Nerurkar VR. Maturation of dengue virus nonstructural protein 4B in monocytes enhances production of dengue hemorrhagic fever-associated chemokines and cytokines. Virology 2011; 418:27-39. [PMID: 21810535 DOI: 10.1016/j.virol.2011.07.006] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2011] [Revised: 04/25/2011] [Accepted: 07/03/2011] [Indexed: 11/19/2022]
Abstract
High levels of viremia and chemokines and cytokines underlie the progression of severe dengue disease. Dengue virus (DENV) preferentially infects peripheral blood monocytes, which secrete elevated levels of immunomediators in patients with severe disease. Further, DENV nonstructural proteins (NS) are capable of modifying intracellular signaling, including interferon inhibition. We demonstrate that peak secretions of immunomediators such as IL-6, IL-8, IP-10, TNFα or IFNγ in DENV-infected monocytes correlate with maximum virus production and NS4B and NS5 are primarily responsible for the induction of immunomediators. Furthermore, we demonstrate that sequential NS4AB processing initiated by the viral protease NS2B3(pro) and via the intermediate 2KNS4B significantly enhances immunomediator induction. While the 2K-signal peptide is not essential for immunomediator induction, it plays a synergistic role with NS4B. These data suggest that NS4B maturation is important during innate immune signaling in DENV-infected monocytes. Given similar NS4B topologies and polyprotein processing across flaviviruses, NS4B may be an attractive target for developing Flavivirus-wide therapeutic interventions.
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Affiliation(s)
- James F Kelley
- Department of Tropical Medicine, Medical Microbiology and Pharmacology, John A. Burns School of Medicine, University of Hawaii at Manoa, Honolulu, HI 96813, USA
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20
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Namitha KK, Archana SN, Negi PS. Expression of carotenoid biosynthetic pathway genes and changes in carotenoids during ripening in tomato (Lycopersicon esculentum). Food Funct 2011; 2:168-73. [PMID: 21779575 DOI: 10.1039/c0fo00169d] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
To study the expression pattern of carotenoid biosynthetic pathway genes, changes in their expression at different stages of maturity in tomato fruit (cv. Arka Ahuti) were investigated. The genes regulating carotenoid production were quantified by a dot blot method using a DIG (dioxigenin) labelling and detection kit. The results revealed that there was an increase in the levels of upstream genes of the carotenoid biosynthetic pathway such as 1-deoxy-d-xylulose-5-phosphate reductoisomerase (DXR), 4-hydroxy-3-methyl-but-2-enyl diphosphate reductase (Lyt B), phytoene synthase (PSY), phytoene desaturase (PDS) and ζ-carotene desaturase (ZDS) by 2-4 fold at the breaker stage as compared to leaf. The lycopene and β-carotene content was analyzed by HPLC at different stages of maturity. The lycopene (15.33 ± 0.24 mg per 100 g) and β-carotene (10.37 ± 0.46 mg per 100 g) content were found to be highest at 5 days post-breaker and 10 days post-breaker stage, respectively. The lycopene accumulation pattern also coincided with the color values at different stages of maturity. These studies may provide insight into devising gene-based strategies for enhancing carotenoid accumulation in tomato fruits.
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21
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Conde J, de la Fuente JM, Baptista PV. In vitro transcription and translation inhibition via DNA functionalized gold nanoparticles. NANOTECHNOLOGY 2010; 21:505101. [PMID: 21098932 DOI: 10.1088/0957-4484/21/50/505101] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
The use of gold nanoparticles (AuNPs) has been gaining momentum as vectors for gene silencing strategies, combining the AuNPs' ease of functionalization with DNA and/or siRNA, high loading capacity and fast uptake by target cells. Here, we used AuNP functionalized with thiolated oligonucleotides to specifically inhibit transcription in vitro, demonstrating the synergetic effect between AuNPs and a specific antisense sequence that blocks the T7 promoter region. Also, AuNPs efficiently protect the antisense oligonucleotide against nuclease degradation, which can thus retain its inhibitory potential. In addition, we demonstrate that AuNPs functionalized with a thiolated oligonucleotide complementary to the ribosome binding site and the start codon, effectively shut down in vitro translation. Together, these two approaches can provide for a simple yet robust experimental set up to test for efficient gene silencing of AuNP-DNA conjugates. What is more, these results show that appropriate functionalization of AuNPs can be used as a dual targeting approach to an enhanced control of gene expression-inhibition of both transcription and translation.
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Affiliation(s)
- J Conde
- Centro de Investigação em Genética Molecular Humana, Departamento de Ciências da Vida, Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa, 2829-516 Caparica, Portugal
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22
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Nissan T, Rajyaguru P, She M, Song H, Parker R. Decapping activators in Saccharomyces cerevisiae act by multiple mechanisms. Mol Cell 2010; 39:773-83. [PMID: 20832728 PMCID: PMC2946179 DOI: 10.1016/j.molcel.2010.08.025] [Citation(s) in RCA: 185] [Impact Index Per Article: 13.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2009] [Revised: 04/30/2010] [Accepted: 07/01/2010] [Indexed: 11/23/2022]
Abstract
Eukaryotic mRNA degradation often occurs in a process whereby translation initiation is inhibited and the mRNA is targeted for decapping. In yeast cells, Pat1, Scd6, Edc3, and Dhh1 all function to promote decapping by an unknown mechanism(s). We demonstrate that purified Scd6 and a region of Pat1 directly repress translation in vitro by limiting the formation of a stable 48S preinitiation complex. Moreover, while Pat1, Edc3, Dhh1, and Scd6 all bind the decapping enzyme, only Pat1 and Edc3 enhance its activity. We also identify numerous direct interactions between Pat1, Dcp1, Dcp2, Dhh1, Scd6, Edc3, Xrn1, and the Lsm1-7 complex. These observations identify three classes of decapping activators that function to directly repress translation initiation and/or stimulate Dcp1/2. Moreover, Pat1 is identified as critical in mRNA decay by first inhibiting translation initiation, then serving as a scaffold to recruit components of the decapping complex, and finally activating Dcp2.
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Affiliation(s)
- Tracy Nissan
- Department of Molecular Biology, Umeå University, Umeå, Sweden
| | - Purusharth Rajyaguru
- Department of Molecular and Cellular Biology and Howard Hughes Medical Institute, University of Arizona, Tucson, Arizona, 85721-0106, USA
| | - Meipei She
- Department of Molecular and Cellular Biology and Howard Hughes Medical Institute, University of Arizona, Tucson, Arizona, 85721-0106, USA
- Laboratory of Macromolecular Structure, Institute of Molecular and Cell Biology, Proteos, Singapore 138673
| | - Haiwei Song
- Laboratory of Macromolecular Structure, Institute of Molecular and Cell Biology, Proteos, Singapore 138673
| | - Roy Parker
- Department of Molecular and Cellular Biology and Howard Hughes Medical Institute, University of Arizona, Tucson, Arizona, 85721-0106, USA
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23
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Pickin KA, Ezenwajiaku N, Overcash H, Sethi M, Knecht MR, Paumi CM. Suppression of Ycf1p function by Cka1p-dependent phosphorylation is attenuated in response to salt stress. FEMS Yeast Res 2010; 10:839-57. [PMID: 20812950 DOI: 10.1111/j.1567-1364.2010.00677.x] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
The yeast vacuolar membrane protein Ycf1p and its mammalian counterpart, MRP1, belong to the ABCC subfamily of ATP-binding cassette transporters. Genetic evidence suggests that the yeast casein kinase 2α, Cka1p, negatively regulates Ycf1p function via phosphorylation of Ser251 within the N-terminus. In this study, we provide strong evidence that Cka1p regulates Ycf1p function via phosphorylation of Ser251. We show that the CK2 holoenzyme interacts with Ycf1p. However, genetic analysis suggests that only Cka1p is required for Ser251 phosphorylation, as the deletion of CKA1 significantly reduces Ser251 phosphorylation in vivo. Furthermore, purified recombinant Cka1p phosphorylates a Ycf1p-derived peptide containing Ser251. We also demonstrate that Ycf1p function is induced in response to high salt stress. Induction of the Ycf1p function strongly correlates with reduced phosphorylation of Ser251. Importantly, Cka1p activity in vivo is similarly reduced in response to salt stress, consistent with our finding that Cka1p directly phosphorylates Ser251 of Ycf1p. We provide genetic and biochemical evidence that strongly suggests that the induction of Ycf1p function is the result of decreased phosphorylation of Ser251. In conclusion, our work demonstrates a novel biochemical role for Cka1p regulation of Ycf1p function in the cellular response of yeast to salt stress.
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Affiliation(s)
- Kerry A Pickin
- Department of Toxicology, University of Kentucky, Lexington, KY 40536, USA
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24
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Sultana H, Neelakanta G, Kantor FS, Malawista SE, Fish D, Montgomery RR, Fikrig E. Anaplasma phagocytophilum induces actin phosphorylation to selectively regulate gene transcription in Ixodes scapularis ticks. ACTA ACUST UNITED AC 2010; 207:1727-43. [PMID: 20660616 PMCID: PMC2916137 DOI: 10.1084/jem.20100276] [Citation(s) in RCA: 64] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Anaplasma phagocytophilum, the agent of human anaplasmosis, persists in ticks and mammals. We show that A. phagocytophilum induces the phosphorylation of actin in an Ixodes ricinus tick cell line and Ixodes scapularis ticks, to alter the ratio of monomeric/filamentous (G/F) actin. A. phagocytophilum–induced actin phosphorylation was dependent on Ixodes p21-activated kinase (IPAK1)–mediated signaling. A. phagocytophilum stimulated IPAK1 activity via the G protein–coupled receptor Gβγ subunits, which mediated phosphoinositide 3-kinase (PI3K) activation. Disruption of Ixodes gβγ, pi3k, and pak1 reduced actin phosphorylation and bacterial acquisition by ticks. A. phagocytophilum–induced actin phosphorylation resulted in increased nuclear G actin and phosphorylated actin. The latter, in association with RNA polymerase II (RNAPII), enhanced binding of TATA box–binding protein to RNAPII and selectively promoted expression of salp16, a gene crucial for A. phagocytophilum survival. These data define a mechanism that A. phagocytophilum uses to selectively alter arthropod gene expression for its benefit and suggest new strategies to interfere with the life cycle of this intracellular pathogen, and perhaps other Rickettsia-related microbes of medical importance.
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Affiliation(s)
- Hameeda Sultana
- Section of Infectious Diseases, Department of Internal Medicine, Yale University School of Medicine, New Haven, CT 06520, USA
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25
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Current awareness on yeast. Yeast 2010. [DOI: 10.1002/yea.1717] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
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