1
|
Abood A, Mesner LD, Jeffery ED, Murali M, Lehe MD, Saquing J, Farber CR, Sheynkman GM. Long-read proteogenomics to connect disease-associated sQTLs to the protein isoform effectors of disease. Am J Hum Genet 2024:S0002-9297(24)00227-1. [PMID: 39079539 DOI: 10.1016/j.ajhg.2024.07.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2024] [Revised: 07/01/2024] [Accepted: 07/02/2024] [Indexed: 08/07/2024] Open
Abstract
A major fraction of loci identified by genome-wide association studies (GWASs) mediate alternative splicing, but mechanistic interpretation is hindered by the technical limitations of short-read RNA sequencing (RNA-seq), which cannot directly link splicing events to full-length protein isoforms. Long-read RNA-seq represents a powerful tool to characterize transcript isoforms, and recently, infer protein isoform existence. Here, we present an approach that integrates information from GWASs, splicing quantitative trait loci (sQTLs), and PacBio long-read RNA-seq in a disease-relevant model to infer the effects of sQTLs on the ultimate protein isoform products they encode. We demonstrate the utility of our approach using bone mineral density (BMD) GWAS data. We identified 1,863 sQTLs from the Genotype-Tissue Expression (GTEx) project in 732 protein-coding genes that colocalized with BMD associations (H4PP ≥ 0.75). We generated PacBio Iso-Seq data (N = ∼22 million full-length reads) on human osteoblasts, identifying 68,326 protein-coding isoforms, of which 17,375 (25%) were unannotated. By casting the sQTLs onto protein isoforms, we connected 809 sQTLs to 2,029 protein isoforms from 441 genes expressed in osteoblasts. Overall, we found that 74 sQTLs influenced isoforms likely impacted by nonsense-mediated decay and 190 that potentially resulted in the expression of unannotated protein isoforms. Finally, we functionally validated colocalizing sQTLs in TPM2, in which siRNA-mediated knockdown in osteoblasts showed two TPM2 isoforms with opposing effects on mineralization but exhibited no effect upon knockdown of the entire gene. Our approach should be to generalize across diverse clinical traits and to provide insights into protein isoform activities modulated by GWAS loci.
Collapse
Affiliation(s)
- Abdullah Abood
- Center for Public Health Genomics, School of Medicine, University of Virginia, Charlottesville, VA 22908, USA; Department of Biochemistry and Molecular Genetics, School of Medicine, University of Virginia, Charlottesville, VA 22908, USA
| | - Larry D Mesner
- Center for Public Health Genomics, School of Medicine, University of Virginia, Charlottesville, VA 22908, USA; Department of Public Health Sciences, University of Virginia, Charlottesville, VA 22908, USA
| | - Erin D Jeffery
- Department of Molecular Physiology and Biological Physics, University of Virginia, Charlottesville, VA, USA
| | - Mayank Murali
- Department of Molecular Physiology and Biological Physics, University of Virginia, Charlottesville, VA, USA
| | - Micah D Lehe
- Department of Molecular Physiology and Biological Physics, University of Virginia, Charlottesville, VA, USA
| | - Jamie Saquing
- Department of Molecular Physiology and Biological Physics, University of Virginia, Charlottesville, VA, USA
| | - Charles R Farber
- Center for Public Health Genomics, School of Medicine, University of Virginia, Charlottesville, VA 22908, USA; Department of Biochemistry and Molecular Genetics, School of Medicine, University of Virginia, Charlottesville, VA 22908, USA; Department of Public Health Sciences, University of Virginia, Charlottesville, VA 22908, USA.
| | - Gloria M Sheynkman
- Center for Public Health Genomics, School of Medicine, University of Virginia, Charlottesville, VA 22908, USA; Department of Molecular Physiology and Biological Physics, University of Virginia, Charlottesville, VA, USA; UVA Comprehensive Cancer Center, University of Virginia, Charlottesville, VA, USA.
| |
Collapse
|
2
|
Liu M, Chen X. N6-Methyladenosine Demethylase ALKBH5 Promotes Pyroptosis by Modulating PTBP1 mRNA Stability in LPS-Induced Myocardial Dysfunction. ACTA CARDIOLOGICA SINICA 2024; 40:312-321. [PMID: 38779157 PMCID: PMC11106622 DOI: 10.6515/acs.202405_40(3).20240127a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 08/14/2023] [Accepted: 01/27/2024] [Indexed: 05/25/2024]
Abstract
Objective This study aims to investigate the mechanism by which alkB homolog 5 (ALKBH5) regulates polypyrimidine tract-binding protein 1 (PTBP1) to mediate cardiomyocyte pyroptosis in sepsis-induced myocardial injury. Methods Lipopolysaccharide (LPS)-exposed H9C2 cell and rat models were established to mimic septic myocardial injury both in vitro and in vivo. The mRNA and protein levels of ALKBH5 and PTBP1 in the LPS-induced cell and septic rat models were detected. CCK-8 and flow cytometry were applied to detect cell viability and pyroptosis. H&E staining was used to observe myocardial tissue damage in rats, and immunohistochemistry to analyze the expression of pyroptosis and inflammation-related proteins in rat tissues. Results Elevated expressions of both ALKBH5 and PTBP1 were found in the myocardial tissues of LPS-induced septic rats. ALKBH5 knockdown could restore the cell viability and cell pyroptosis inhibited by LPS, while ALKBH5 promoted PTBP1 mRNA stability by affecting its N6-methyladenosine (m6A) modification. In vivo experiments showed that PTBP1 knockdown could largely reverse the antiproliferative and pro-pyroptosis effects of ALKBH5 in LPS-exposed H9C2 cells. ALKBH5 knockdown in in vivo experiments was found to suppress the expressions of pyroptosis biomarkers and attenuate myocardial injury in septic rats. Conclusions ALKBH5 promoted mRNA stability and the expression of PTBP1 through m6A modification to induce pyroptosis in cardiomyocytes and ultimately aggravate sepsis-induced myocardial dysfunction.
Collapse
Affiliation(s)
- Min Liu
- Department of Intensive Care
| | - Xiyun Chen
- Department of Gynecology, The First Hospital of Changsha, Changsha, Hunan, P.R. China
| |
Collapse
|
3
|
Li Q, Zhang W, Qiao XY, Liu C, Dao JJ, Qiao CM, Cui C, Shen YQ, Zhao WJ. Reducing polypyrimidine tract‑binding protein 1 fails to promote neuronal transdifferentiation on HT22 and mouse astrocyte cells under physiological conditions. Exp Ther Med 2024; 27:72. [PMID: 38234625 PMCID: PMC10792410 DOI: 10.3892/etm.2023.12360] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2023] [Accepted: 11/27/2023] [Indexed: 01/19/2024] Open
Abstract
In contrast to prior findings that have illustrated the conversion of non-neuronal cells into functional neurons through the specific targeting of polypyrimidine tract-binding protein 1 (PTBP1), accumulated evidence suggests the impracticality of inducing neuronal transdifferentiation through suppressing PTBP1 expression in pathological circumstances. Therefore, the present study explored the effect of knocking down PTBP1 under physiological conditions on the transdifferentiation of mouse hippocampal neuron HT22 cells and mouse astrocyte (MA) cells. A total of 20 µM negative control small interfering (si)RNA and siRNA targeting PTBP1 were transfected into HT22 and MA cells using Lipo8000™ for 3 and 5 days, respectively. The expression of early neuronal marker βIII-Tubulin and mature neuronal markers NeuN and microtubule-associated protein 2 (MAP2) were detected using western blotting. In addition, βIII-tubulin, NeuN and MAP2 were labeled with immunofluorescence staining to evaluate neuronal cell differentiation in response to PTBP1 downregulation. Under physiological conditions, no significant changes in the expression of βIII-Tubulin, NeuN and MAP2 were found after 3 and 5 days of knockdown of PTBP1 protein in both HT22 and MA cells. In addition, the immunofluorescence staining results showed no apparent transdifferentiation in maker levels and morphology. The results suggested that the knockdown of PTBP1 failed to induce neuronal differentiation under physiological conditions.
Collapse
Affiliation(s)
- Qian Li
- Department of Cell Biology, Wuxi School of Medicine, Jiangnan University, Wuxi, Jiangsu 214122, P.R. China
| | - Wei Zhang
- Department of Cell Biology, Wuxi School of Medicine, Jiangnan University, Wuxi, Jiangsu 214122, P.R. China
- Department of Pathogen Biology, Guizhou Nursing Vocational College, Guiyang, Guizhou 550081, P.R. China
| | - Xin-Yu Qiao
- Department of Cell Biology, Wuxi School of Medicine, Jiangnan University, Wuxi, Jiangsu 214122, P.R. China
| | - Chong Liu
- Department of Cell Biology, Wuxi School of Medicine, Jiangnan University, Wuxi, Jiangsu 214122, P.R. China
| | - Ji-Ji Dao
- Department of Cell Biology, Wuxi School of Medicine, Jiangnan University, Wuxi, Jiangsu 214122, P.R. China
| | - Chen-Meng Qiao
- Department of Neurodegeneration and Neuroinjury, Wuxi School of Medicine, Jiangnan University, Wuxi, Jiangsu 214122, P.R. China
| | - Chun Cui
- Department of Neurodegeneration and Neuroinjury, Wuxi School of Medicine, Jiangnan University, Wuxi, Jiangsu 214122, P.R. China
| | - Yan-Qin Shen
- Department of Neurodegeneration and Neuroinjury, Wuxi School of Medicine, Jiangnan University, Wuxi, Jiangsu 214122, P.R. China
| | - Wei-Jiang Zhao
- Department of Cell Biology, Wuxi School of Medicine, Jiangnan University, Wuxi, Jiangsu 214122, P.R. China
| |
Collapse
|
4
|
Du Y, Cao L, Wang S, Guo L, Tan L, Liu H, Feng Y, Wu W. Differences in alternative splicing and their potential underlying factors between animals and plants. J Adv Res 2023:S2090-1232(23)00354-5. [PMID: 37981087 DOI: 10.1016/j.jare.2023.11.017] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2023] [Revised: 08/16/2023] [Accepted: 11/14/2023] [Indexed: 11/21/2023] Open
Abstract
BACKGROUND Alternative splicing (AS), a posttranscriptional process, contributes to the complexity of transcripts from a limited number of genes in a genome, and AS is considered a great source of genetic and phenotypic diversity in eukaryotes. In animals, AS is tightly regulated during the processes of cell growth and differentiation, and its dysregulation is involved in many diseases, including cancers. Likewise, in plants, AS occurs in all stages of plant growth and development, and it seems to play important roles in the rapid reprogramming of genes in response to environmental stressors. To date, the prevalence and functional roles of AS have been extensively reviewed in animals and plants. However, AS differences between animals and plants, especially their underlying molecular mechanisms and impact factors, are anecdotal and rarely reviewed. AIM OF REVIEW This review aims to broaden our understanding of AS roles in a variety of biological processes and provide insights into the underlying mechanisms and impact factors likely leading to AS differences between animals and plants. KEY SCIENTIFIC CONCEPTS OF REVIEW We briefly summarize the roles of AS regulation in physiological and biochemical activities in animals and plants. Then, we underline the differences in the process of AS between plants and animals and especially analyze the potential impact factors, such as gene exon/intron architecture, 5'/3' untranslated regions (UTRs), spliceosome components, chromatin dynamics and transcription speeds, splicing factors [serine/arginine-rich (SR) proteins and heterogeneous nuclear ribonucleoproteins (hnRNPs)], noncoding RNAs, and environmental stimuli, which might lead to the differences. Moreover, we compare the nonsense-mediated mRNA decay (NMD)-mediated turnover of the transcripts with a premature termination codon (PTC) in animals and plants. Finally, we summarize the current AS knowledge published in animals versus plants and discuss the potential development of disease therapies and superior crops in the future.
Collapse
Affiliation(s)
- Yunfei Du
- State Key Laboratory of Subtropical Silviculture, Zhejiang A&F University, Lin'an, 311300, Hangzhou, China
| | - Lu Cao
- State Key Laboratory of Subtropical Silviculture, Zhejiang A&F University, Lin'an, 311300, Hangzhou, China
| | - Shuo Wang
- State Key Laboratory of Subtropical Silviculture, Zhejiang A&F University, Lin'an, 311300, Hangzhou, China
| | - Liangyu Guo
- State Key Laboratory of Subtropical Silviculture, Zhejiang A&F University, Lin'an, 311300, Hangzhou, China
| | - Lingling Tan
- State Key Laboratory of Subtropical Silviculture, Zhejiang A&F University, Lin'an, 311300, Hangzhou, China
| | - Hua Liu
- State Key Laboratory of Subtropical Silviculture, Zhejiang A&F University, Lin'an, 311300, Hangzhou, China
| | - Ying Feng
- Key Laboratory of Nutrition, Metabolism and Food Safety, Shanghai Institute of Nutrition and Health (SINH), Chinese Academy of Sciences (CAS), Shanghai 200032, China.
| | - Wenwu Wu
- State Key Laboratory of Subtropical Silviculture, Zhejiang A&F University, Lin'an, 311300, Hangzhou, China.
| |
Collapse
|
5
|
Varesi A, Campagnoli LIM, Barbieri A, Rossi L, Ricevuti G, Esposito C, Chirumbolo S, Marchesi N, Pascale A. RNA binding proteins in senescence: A potential common linker for age-related diseases? Ageing Res Rev 2023; 88:101958. [PMID: 37211318 DOI: 10.1016/j.arr.2023.101958] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2023] [Revised: 05/09/2023] [Accepted: 05/18/2023] [Indexed: 05/23/2023]
Abstract
Aging represents the major risk factor for the onset and/or progression of various disorders including neurodegenerative diseases, metabolic disorders, and bone-related defects. As the average age of the population is predicted to exponentially increase in the coming years, understanding the molecular mechanisms underlying the development of aging-related diseases and the discovery of new therapeutic approaches remain pivotal. Well-reported hallmarks of aging are cellular senescence, genome instability, autophagy impairment, mitochondria dysfunction, dysbiosis, telomere attrition, metabolic dysregulation, epigenetic alterations, low-grade chronic inflammation, stem cell exhaustion, altered cell-to-cell communication and impaired proteostasis. With few exceptions, however, many of the molecular players implicated within these processes as well as their role in disease development remain largely unknown. RNA binding proteins (RBPs) are known to regulate gene expression by dictating at post-transcriptional level the fate of nascent transcripts. Their activity ranges from directing primary mRNA maturation and trafficking to modulation of transcript stability and/or translation. Accumulating evidence has shown that RBPs are emerging as key regulators of aging and aging-related diseases, with the potential to become new diagnostic and therapeutic tools to prevent or delay aging processes. In this review, we summarize the role of RBPs in promoting cellular senescence and we highlight their dysregulation in the pathogenesis and progression of the main aging-related diseases, with the aim of encouraging further investigations that will help to better disclose this novel and captivating molecular scenario.
Collapse
Affiliation(s)
- Angelica Varesi
- Department of Biology and Biotechnology, University of Pavia, Pavia, Italy.
| | | | - Annalisa Barbieri
- Department of Drug Sciences, Section of Pharmacology, University of Pavia, Pavia, Italy
| | - Lorenzo Rossi
- Institute of Molecular Biology and Biophysics, ETH Zurich, Zurich, Switzerland
| | | | - Ciro Esposito
- Department of Internal Medicine and Therapeutics, University of Pavia, Italy; Nephrology and dialysis unit, ICS S. Maugeri SPA SB Hospital, Pavia, Italy; High School in Geriatrics, University of Pavia, Italy
| | | | - Nicoletta Marchesi
- Department of Drug Sciences, Section of Pharmacology, University of Pavia, Pavia, Italy
| | - Alessia Pascale
- Department of Drug Sciences, Section of Pharmacology, University of Pavia, Pavia, Italy.
| |
Collapse
|
6
|
Bushra S, Lin YN, Joudaki A, Ito M, Ohkawara B, Ohno K, Masuda A. Neural Isoforms of Agrin Are Generated by Reduced PTBP1-RNA Interaction Network Spanning the Neuron-Specific Splicing Regions in AGRN. Int J Mol Sci 2023; 24:ijms24087420. [PMID: 37108583 PMCID: PMC10139058 DOI: 10.3390/ijms24087420] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2023] [Revised: 04/12/2023] [Accepted: 04/14/2023] [Indexed: 04/29/2023] Open
Abstract
Agrin is a heparan sulfate proteoglycan essential for the clustering of acetylcholine receptors at the neuromuscular junction. Neuron-specific isoforms of agrin are generated by alternative inclusion of three exons, called Y, Z8, and Z11 exons, although their processing mechanisms remain elusive. We found, by inspection of splicing cis-elements into the human AGRN gene, that binding sites for polypyrimidine tract binding protein 1 (PTBP1) were extensively enriched around Y and Z exons. PTBP1-silencing enhanced the coordinated inclusion of Y and Z exons in human SH-SY5Y neuronal cells, even though three constitutive exons are flanked by these alternative exons. Deletion analysis using minigenes identified five PTBP1-binding sites with remarkable splicing repression activities around Y and Z exons. Furthermore, artificial tethering experiments indicated that binding of a single PTBP1 molecule to any of these sites represses nearby Y or Z exons as well as the other distal exons. The RRM4 domain of PTBP1, which is required for looping out a target RNA segment, was likely to play a crucial role in the repression. Neuronal differentiation downregulates PTBP1 expression and promotes the coordinated inclusion of Y and Z exons. We propose that the reduction in the PTPB1-RNA network spanning these alternative exons is essential for the generation of the neuron-specific agrin isoforms.
Collapse
Affiliation(s)
- Samira Bushra
- Division of Neurogenetics, Center for Neurological Diseases and Cancer, Nagoya University Graduate School of Medicine, Nagoya 466-8550, Aichi, Japan
| | - Ying-Ni Lin
- Division of Neurogenetics, Center for Neurological Diseases and Cancer, Nagoya University Graduate School of Medicine, Nagoya 466-8550, Aichi, Japan
| | - Atefeh Joudaki
- Division of Neurogenetics, Center for Neurological Diseases and Cancer, Nagoya University Graduate School of Medicine, Nagoya 466-8550, Aichi, Japan
| | - Mikako Ito
- Division of Neurogenetics, Center for Neurological Diseases and Cancer, Nagoya University Graduate School of Medicine, Nagoya 466-8550, Aichi, Japan
| | - Bisei Ohkawara
- Division of Neurogenetics, Center for Neurological Diseases and Cancer, Nagoya University Graduate School of Medicine, Nagoya 466-8550, Aichi, Japan
| | - Kinji Ohno
- Division of Neurogenetics, Center for Neurological Diseases and Cancer, Nagoya University Graduate School of Medicine, Nagoya 466-8550, Aichi, Japan
| | - Akio Masuda
- Division of Neurogenetics, Center for Neurological Diseases and Cancer, Nagoya University Graduate School of Medicine, Nagoya 466-8550, Aichi, Japan
| |
Collapse
|
7
|
Abood A, Mesner LD, Jeffery ED, Murali M, Lehe M, Saquing J, Farber CR, Sheynkman GM. Long-read proteogenomics to connect disease-associated sQTLs to the protein isoform effectors of disease. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.03.17.531557. [PMID: 36993769 PMCID: PMC10055087 DOI: 10.1101/2023.03.17.531557] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/31/2023]
Abstract
A major fraction of loci identified by genome-wide association studies (GWASs) lead to alterations in alternative splicing, but interpretation of how such alterations impact proteins is hindered by the technical limitations of short-read RNA-seq, which cannot directly link splicing events to full-length transcript or protein isoforms. Long-read RNA-seq represents a powerful tool to define and quantify transcript isoforms, and recently, infer protein isoform existence. Here we present a novel approach that integrates information from GWAS, splicing QTL (sQTL), and PacBio long-read RNA-seq in a disease-relevant model to infer the effects of sQTLs on the ultimate protein isoform products they encode. We demonstrate the utility of our approach using bone mineral density (BMD) GWAS data. We identified 1,863 sQTLs from the Genotype-Tissue Expression (GTEx) project in 732 protein-coding genes which colocalized with BMD associations (H 4 PP ≥ 0.75). We generated deep coverage PacBio long-read RNA-seq data (N=∼22 million full-length reads) on human osteoblasts, identifying 68,326 protein-coding isoforms, of which 17,375 (25%) were novel. By casting the colocalized sQTLs directly onto protein isoforms, we connected 809 sQTLs to 2,029 protein isoforms from 441 genes expressed in osteoblasts. Using these data, we created one of the first proteome-scale resources defining full-length isoforms impacted by colocalized sQTLs. Overall, we found that 74 sQTLs influenced isoforms likely impacted by nonsense mediated decay (NMD) and 190 that potentially resulted in the expression of new protein isoforms. Finally, we identified colocalizing sQTLs in TPM2 for splice junctions between two mutually exclusive exons, and two different transcript termination sites, making it impossible to interpret without long-read RNA-seq data. siRNA mediated knockdown in osteoblasts showed two TPM2 isoforms with opposing effects on mineralization. We expect our approach to be widely generalizable across diverse clinical traits and accelerate system-scale analyses of protein isoform activities modulated by GWAS loci.
Collapse
|
8
|
Han Z, Wu Z, Gong W, Zhou W, Chen L, Li C. Allosteric mechanism for SL RNA recognition by polypyrimidine tract binding protein RRM1: An atomistic MD simulation and network-based study. Int J Biol Macromol 2022; 221:763-772. [PMID: 36058398 DOI: 10.1016/j.ijbiomac.2022.08.181] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2022] [Revised: 08/20/2022] [Accepted: 08/27/2022] [Indexed: 12/01/2022]
Abstract
Polypyrimidine tract-binding protein (PTB), an RNA-binding protein, is involved in the regulation of diverse processes in mRNA metabolism. However, the allosteric modulation of its binding with RNA remains unclear. We explore the dynamic characteristics of PTB RNA recognition motif 1 (RRM1) in its RNA-free and wild-type/mutant RNA-bound states to understand the issues using molecular dynamics (MD) simulation, perturbation response scanning (PRS) and protein structure network (PSN) models. It is found that RNA binding strengthens RRM1 stability, while L151G mutation in α3 helix far away from the interface makes the complex unstable. The latter is caused by long-distance dynamic couplings, which makes intermolecular electrostatic and entropy energies unfavorable. The weakened couplings between interface β sheets and C-terminal parts upon mutation reveal RNA recognition is co-regulated by these regions. Interestingly, PRS analysis reveals the allostery caused by the perturbation on α3 helix has already been pre-encoded in the equilibrium dynamics of the protein structure. PSN analysis shows the details of the allosteric signal transmission, revealing the necessity of strong couplings between α3 helix and interface for maintaining the high binding affinity. This study sheds light on the mechanisms of PTB allostery and RNA recognition and can provide important information for drug design.
Collapse
Affiliation(s)
- Zhongjie Han
- Faculty of Environmental and Life Sciences, Beijing University of Technology, Beijing 100124, China
| | - Zhixiang Wu
- Faculty of Environmental and Life Sciences, Beijing University of Technology, Beijing 100124, China
| | - Weikang Gong
- Faculty of Environmental and Life Sciences, Beijing University of Technology, Beijing 100124, China
| | - Wenxue Zhou
- Faculty of Environmental and Life Sciences, Beijing University of Technology, Beijing 100124, China
| | - Lei Chen
- Faculty of Environmental and Life Sciences, Beijing University of Technology, Beijing 100124, China
| | - Chunhua Li
- Faculty of Environmental and Life Sciences, Beijing University of Technology, Beijing 100124, China.
| |
Collapse
|
9
|
Westcott CE, Qazi S, Maiocco AM, Mukhopadhyay S, Sokoloski KJ. Binding of hnRNP I-vRNA Regulates Sindbis Virus Structural Protein Expression to Promote Particle Infectivity. Viruses 2022; 14:v14071423. [PMID: 35891402 PMCID: PMC9318202 DOI: 10.3390/v14071423] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2022] [Revised: 06/09/2022] [Accepted: 06/27/2022] [Indexed: 12/04/2022] Open
Abstract
Alphaviruses cause significant outbreaks of febrile illness and debilitating multi-joint arthritis for prolonged periods after initial infection. We have previously reported that several host hnRNP proteins bind to the Sindbis virus (SINV) RNAs, and disrupting the sites of these RNA-protein interactions results in decreased viral titers in tissue culture models of infection. Intriguingly, the primary molecular defect associated with the disruption of the hnRNP interactions is enhanced viral structural protein expression; however, the precise underlying mechanisms spurring the enhanced gene expression remain unknown. Moreover, our previous efforts were unable to functionally dissect whether the observed phenotypes were due to the loss of hnRNP binding or the incorporation of polymorphisms into the primary nucleotide sequence of SINV. To determine if the loss of hnRNP binding was the primary cause of attenuation or if the disruption of the RNA sequence itself was responsible for the observed phenotypes, we utilized an innovative protein tethering approach to restore the binding of the hnRNP proteins in the absence of the native interaction site. Specifically, we reconstituted the hnRNP I interaction by incorporating the 20nt bovine immunodeficiency virus transactivation RNA response (BIV-TAR) at the site of the native hnRNP I interaction sequence, which will bind with high specificity to proteins tagged with a TAT peptide. The reestablishment of the hnRNP I-vRNA interaction via the BIV-TAR/TAT tethering approach restored the phenotype back to wild-type levels. This included an apparent decrease in structural protein expression in the absence of the native primary nucleotide sequences corresponding to the hnRNP I interaction site. Collectively, the characterization of the hnRNP I interaction site elucidated the role of hnRNPs during viral infection.
Collapse
Affiliation(s)
- Claire E. Westcott
- Department of Microbiology and Immunology, School of Medicine, University of Louisville, Louisville, KY 40202, USA;
| | - Shefah Qazi
- Department of Biology, Indiana University—Bloomington, Bloomington, IN 47405, USA; (S.Q.); (S.M.)
| | - Anna M. Maiocco
- Center for Predictive Medicine and Emerging Infectious Diseases, School of Medicine, University of Louisville, Louisville, KY 40202, USA;
| | - Suchetana Mukhopadhyay
- Department of Biology, Indiana University—Bloomington, Bloomington, IN 47405, USA; (S.Q.); (S.M.)
| | - Kevin J. Sokoloski
- Department of Microbiology and Immunology, School of Medicine, University of Louisville, Louisville, KY 40202, USA;
- Center for Predictive Medicine and Emerging Infectious Diseases, School of Medicine, University of Louisville, Louisville, KY 40202, USA;
- Correspondence: ; Tel.: +1-(502)-852-1249
| |
Collapse
|