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Ren J, Yu L, Zhang Q, Ren P, Cai Y, Wang X, Lan K, Wu S. AIMP2 restricts EV71 replication by recruiting SMURF2 to promote the degradation of 3D polymerase. Virol Sin 2024; 39:632-644. [PMID: 38945214 DOI: 10.1016/j.virs.2024.06.009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2024] [Accepted: 06/25/2024] [Indexed: 07/02/2024] Open
Abstract
Hand, foot and mouth disease (HFMD), mainly caused by enterovirus 71 (EV71), has frequently occurred in the Asia-Pacific region, posing a significant threat to the health of infants and young children. Therefore, research on the infection mechanism and pathogenicity of enteroviruses is increasingly becoming important. The 3D polymerase, as the most critical RNA-dependent RNA polymerase (RdRp) for EV71 replication, is widely targeted to inhibit EV71 infection. In this study, we identified a novel host protein, AIMP2, capable of binding to 3D polymerase and inhibiting EV71 infection. Subsequent investigations revealed that AIMP2 recruits the E3 ligase SMURF2, which mediates the polyubiquitination and degradation of 3D polymerase. Furthermore, the antiviral effect of AIMP2 extended to the CVA16 and CVB1 serotypes. Our research has uncovered the dynamic regulatory function of AIMP2 during EV71 infection, revealing a novel antiviral mechanism and providing new insights for the development of antienteroviral therapeutic strategies.
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Affiliation(s)
- Junrui Ren
- State Key Laboratory of Virology, College of Life Sciences, Wuhan University, Wuhan, 430072, China
| | - Lei Yu
- State Key Laboratory of Virology, College of Life Sciences, Wuhan University, Wuhan, 430072, China; Medical Research Institute, Wuhan University, Wuhan, 430072, China
| | - Qiuhan Zhang
- State Key Laboratory of Virology, College of Life Sciences, Wuhan University, Wuhan, 430072, China; Medical Research Institute, Wuhan University, Wuhan, 430072, China
| | - Pengyu Ren
- State Key Laboratory of Virology, College of Life Sciences, Wuhan University, Wuhan, 430072, China
| | - Yumeng Cai
- State Key Laboratory of Virology, College of Life Sciences, Wuhan University, Wuhan, 430072, China
| | - Xueyun Wang
- State Key Laboratory of Virology, College of Life Sciences, Wuhan University, Wuhan, 430072, China
| | - Ke Lan
- State Key Laboratory of Virology, College of Life Sciences, Wuhan University, Wuhan, 430072, China; Medical Research Institute, Wuhan University, Wuhan, 430072, China; Taikang Center for Life and Medical Sciences, Wuhan University, Wuhan, 430072, China.
| | - Shuwen Wu
- State Key Laboratory of Virology, College of Life Sciences, Wuhan University, Wuhan, 430072, China.
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Bal G, Schneikert J, Li Z, Franke K, Tripathi SR, Zuberbier T, Babina M. CREB Is Indispensable to KIT Function in Human Skin Mast Cells-A Positive Feedback Loop between CREB and KIT Orchestrates Skin Mast Cell Fate. Cells 2023; 13:42. [PMID: 38201246 PMCID: PMC10778115 DOI: 10.3390/cells13010042] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2023] [Revised: 12/18/2023] [Accepted: 12/22/2023] [Indexed: 01/12/2024] Open
Abstract
Skin mast cells (MCs) are critical effector cells in acute allergic reactions, and they contribute to chronic dermatoses like urticaria and atopic and contact dermatitis. KIT represents the cells' crucial receptor tyrosine kinase, which orchestrates proliferation, survival, and functional programs throughout the lifespan. cAMP response element binding protein (CREB), an evolutionarily well-conserved transcription factor (TF), regulates multiple cellular programs, but its function in MCs is poorly understood. We recently reported that CREB is an effector of the SCF (Stem Cell Factor)/KIT axis. Here, we ask whether CREB may also act upstream of KIT to orchestrate its functioning. Primary human MCs were isolated from skin and cultured in SCF+IL-4 (Interleukin-4). Pharmacological inhibition (666-15) and RNA interference served to manipulate CREB function. We studied KIT expression using flow cytometry and RT-qPCR, KIT-mediated signaling using immunoblotting, and cell survival using scatterplot and caspase-3 activity. The proliferation and cycle phases were quantified following BrdU incorporation. Transient CREB perturbation resulted in reduced KIT expression. Conversely, microphthalmia transcription factor (MITF) was unnecessary for KIT maintenance. KIT attenuation secondary to CREB was associated with heavily impaired KIT functional outputs, like anti-apoptosis and cell cycle progression. Likewise, KIT-elicited phosphorylation of ERK1/2 (Extracellular Signal-Regulated Kinase 1/2), AKT, and STAT5 (Signal Transducer and Activator of Transcription) was substantially diminished upon CREB inhibition. Surprisingly, the longer-term interference of CREB led to complete cell elimination, in a way surpassing KIT inhibition. Collectively, we reveal CREB as non-redundant in MCs, with its absence being incompatible with skin MCs' existence. Since SCF/KIT regulates CREB activity and, vice versa, CREB is required for KIT function, a positive feedforward loop between these elements dictates skin MCs' fate.
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Affiliation(s)
- Gürkan Bal
- Fraunhofer Institute for Translational Medicine and Pharmacology ITMP, Immunology and Allergology IA, 12203 Berlin, Germany; (G.B.); (J.S.); (Z.L.); (K.F.); (S.R.T.); (T.Z.)
- Institute of Allergology, Charité–Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin and Humboldt Universität zu Berlin, Hindenburgdamm 30, 12203 Berlin, Germany
| | - Jean Schneikert
- Fraunhofer Institute for Translational Medicine and Pharmacology ITMP, Immunology and Allergology IA, 12203 Berlin, Germany; (G.B.); (J.S.); (Z.L.); (K.F.); (S.R.T.); (T.Z.)
- Institute of Allergology, Charité–Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin and Humboldt Universität zu Berlin, Hindenburgdamm 30, 12203 Berlin, Germany
| | - Zhuoran Li
- Fraunhofer Institute for Translational Medicine and Pharmacology ITMP, Immunology and Allergology IA, 12203 Berlin, Germany; (G.B.); (J.S.); (Z.L.); (K.F.); (S.R.T.); (T.Z.)
- Institute of Allergology, Charité–Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin and Humboldt Universität zu Berlin, Hindenburgdamm 30, 12203 Berlin, Germany
| | - Kristin Franke
- Fraunhofer Institute for Translational Medicine and Pharmacology ITMP, Immunology and Allergology IA, 12203 Berlin, Germany; (G.B.); (J.S.); (Z.L.); (K.F.); (S.R.T.); (T.Z.)
- Institute of Allergology, Charité–Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin and Humboldt Universität zu Berlin, Hindenburgdamm 30, 12203 Berlin, Germany
| | - Shiva Raj Tripathi
- Fraunhofer Institute for Translational Medicine and Pharmacology ITMP, Immunology and Allergology IA, 12203 Berlin, Germany; (G.B.); (J.S.); (Z.L.); (K.F.); (S.R.T.); (T.Z.)
- Institute of Allergology, Charité–Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin and Humboldt Universität zu Berlin, Hindenburgdamm 30, 12203 Berlin, Germany
| | - Torsten Zuberbier
- Fraunhofer Institute for Translational Medicine and Pharmacology ITMP, Immunology and Allergology IA, 12203 Berlin, Germany; (G.B.); (J.S.); (Z.L.); (K.F.); (S.R.T.); (T.Z.)
- Institute of Allergology, Charité–Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin and Humboldt Universität zu Berlin, Hindenburgdamm 30, 12203 Berlin, Germany
| | - Magda Babina
- Fraunhofer Institute for Translational Medicine and Pharmacology ITMP, Immunology and Allergology IA, 12203 Berlin, Germany; (G.B.); (J.S.); (Z.L.); (K.F.); (S.R.T.); (T.Z.)
- Institute of Allergology, Charité–Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin and Humboldt Universität zu Berlin, Hindenburgdamm 30, 12203 Berlin, Germany
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Carpio-Escalona LV, González-de-Olano D. Immunological and Non-Immunological Risk Factors in Anaphylaxis. CURRENT TREATMENT OPTIONS IN ALLERGY 2022. [DOI: 10.1007/s40521-022-00319-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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4
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Hwang BJ, Jang Y, Kwon SB, Yu JE, Lim J, Roh YH, Seong BL. RNA-assisted self-assembly of monomeric antigens into virus-like particles as a recombinant vaccine platform. Biomaterials 2021; 269:120650. [PMID: 33465537 DOI: 10.1016/j.biomaterials.2021.120650] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2020] [Revised: 12/15/2020] [Accepted: 12/30/2020] [Indexed: 12/11/2022]
Abstract
Representing highly ordered repetitive structures of antigen macromolecular assemblies, virus-like particles (VLPs) serve as a high-priority vaccine platform against emerging viral infections, as alternatives to traditional cell culture-based vaccines. RNAs can function as chaperones (Chaperna) and are extremely effective in promoting protein folding. Beyond their canonical function as translational adaptors, tRNAs may moonlight as chaperones for the kinetic control of macromolecular antigen assembly. Capitalizing on genomic RNA co-assembly in infectious virions, we present the first report of a biomimetic assembly of viral capsids that was assisted by non-viral host RNAs into genome-free, non-infectious empty particles. Here, we demonstrate the assembly of bacterially-produced soluble norovirus VP1 forming VLPs (n = 180) in vitro. A tRNA-interacting domain (tRID) was genetically fused with the VP1 capsid protein, as a tRNA docking tag, in the bacterial host to transduce chaperna function for de novo viral antigen folding. tRID/tRNA removal prompted the in vitro assembly of monomeric antigens into highly ordered repetitive structures that elicited robust protective immune responses after immunization. The chaperna-based assembly of monomeric antigens will impact the development and deployment of VLP vaccines for emerging and re-emerging viral infections.
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Affiliation(s)
- Beom Jeung Hwang
- Department of Biotechnology, College of Life Science and Biotechnology, Yonsei University, 50 Yonsei-ro, Seodaemun-gu, Seoul, 03722, Republic of Korea; Vaccine Innovative Technology Alliance-Korea, Yonsei University, Seoul, 03722, Republic of Korea
| | - Yohan Jang
- Department of Biological Sciences and Biotechnology Major in Bio-Vaccine Engineering, Andong National University, Andong, South Korea
| | - Soon Bin Kwon
- Department of Biotechnology, College of Life Science and Biotechnology, Yonsei University, 50 Yonsei-ro, Seodaemun-gu, Seoul, 03722, Republic of Korea
| | - Ji Eun Yu
- Department of Biotechnology, College of Life Science and Biotechnology, Yonsei University, 50 Yonsei-ro, Seodaemun-gu, Seoul, 03722, Republic of Korea
| | - Jongkwan Lim
- Department of Biotechnology, College of Life Science and Biotechnology, Yonsei University, 50 Yonsei-ro, Seodaemun-gu, Seoul, 03722, Republic of Korea
| | - Young Hoon Roh
- Department of Biotechnology, College of Life Science and Biotechnology, Yonsei University, 50 Yonsei-ro, Seodaemun-gu, Seoul, 03722, Republic of Korea.
| | - Baik L Seong
- Department of Biotechnology, College of Life Science and Biotechnology, Yonsei University, 50 Yonsei-ro, Seodaemun-gu, Seoul, 03722, Republic of Korea; Vaccine Innovative Technology Alliance-Korea, Yonsei University, Seoul, 03722, Republic of Korea.
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5
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Ap 4A Regulates Directional Mobility and Antigen Presentation in Dendritic Cells. iScience 2019; 16:524-534. [PMID: 31254530 PMCID: PMC6595237 DOI: 10.1016/j.isci.2019.05.045] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2019] [Revised: 02/25/2019] [Accepted: 05/30/2019] [Indexed: 12/14/2022] Open
Abstract
The significance of intracellular Ap4A levels over immune activity of dendritic cells (DCs) has been studied in Nudt2fl/fl/CD11c-cre mice. The transgenic mice have been generated by crossing floxed NUDT2 gene mice with DC marker CD11c recombinase (cre) mice. The DCs derived from these mice have higher levels of Ap4A (≈30-fold) compared with those derived from Nudt2+/+ mice. Interestingly, the elevated Ap4A in DCs has led them to possess higher motility and lower directional variability. In addition, the DCs are able to enhance immune protection indicated by the higher cross-presentation of antigen and priming of CD8+ OT-I T cells. Overall, the study denotes prominent impact of Ap4A over the functionality of DCs. The Nudt2fl/fl/CD11c-cre mice could serve as a useful tool to study the influence of Ap4A in the critical immune mechanisms of DCs. DCs of Nudt2fl/fl/CD11c-cre mice exhibit low directional variability and high motility DCs elevate proliferation of OVA-specific T cell receptor transgenic CD8+ T cells The escalation of Ap4A levels in DCs could enhance their immune protective activity Mice can serve as useful functional tool to study the role of Ap4A in various cells
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Kwon SB, Yu JE, Park C, Lee J, Seong BL. Nucleic Acid-Dependent Structural Transition of the Intrinsically Disordered N-Terminal Appended Domain of Human Lysyl-tRNA Synthetase. Int J Mol Sci 2018; 19:ijms19103016. [PMID: 30282926 PMCID: PMC6213541 DOI: 10.3390/ijms19103016] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2018] [Revised: 09/27/2018] [Accepted: 09/29/2018] [Indexed: 12/22/2022] Open
Abstract
Eukaryotic lysyl-tRNA synthetases (LysRS) have an N-terminal appended tRNA-interaction domain (RID) that is absent in their prokaryotic counterparts. This domain is intrinsically disordered and lacks stable structures. The disorder-to-order transition is induced by tRNA binding and has implications on folding and subsequent assembly into multi-tRNA synthetase complexes. Here, we expressed and purified RID from human LysRS (hRID) in Escherichia coli and performed a detailed mutagenesis of the appended domain. hRID was co-purified with nucleic acids during Ni-affinity purification, and cumulative mutations on critical amino acid residues abolished RNA binding. Furthermore, we identified a structural ensemble between disordered and helical structures in non-RNA-binding mutants and an equilibrium shift for wild-type into the helical conformation upon RNA binding. Since mutations that disrupted RNA binding led to an increase in non-functional soluble aggregates, a stabilized RNA-mediated structural transition of the N-terminal appended domain may have implications on the functional organization of human LysRS and multi-tRNA synthetase complexes in vivo.
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Affiliation(s)
- Soon Bin Kwon
- Department of Biotechnology, College of Life Science and Biotechnology, Yonsei University, Seoul 03722, Korea.
| | - Ji Eun Yu
- Department of Biotechnology, College of Life Science and Biotechnology, Yonsei University, Seoul 03722, Korea.
| | - Chan Park
- Department of Biotechnology, College of Life Science and Biotechnology, Yonsei University, Seoul 03722, Korea.
| | - Jiseop Lee
- Department of Biotechnology, College of Life Science and Biotechnology, Yonsei University, Seoul 03722, Korea.
| | - Baik L Seong
- Department of Biotechnology, College of Life Science and Biotechnology, Yonsei University, Seoul 03722, Korea.
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7
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AIMP2-DX2 Promotes the Proliferation, Migration, and Invasion of Nasopharyngeal Carcinoma Cells. BIOMED RESEARCH INTERNATIONAL 2018; 2018:9253036. [PMID: 29854811 PMCID: PMC5941793 DOI: 10.1155/2018/9253036] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/18/2017] [Accepted: 03/08/2018] [Indexed: 12/14/2022]
Abstract
Nasopharyngeal carcinoma (NPC) is a head and neck tumor with high degree of malignancy and with high incidence especially in southern China. AIMP2-DX2, one isoform of the aminoacyl-tRNA synthetase interacting multifunctional proteins (AIMPs), is shown to be a potential target in many cancers. However, the detailed mechanisms of AIMP2-DX2 in NPC development remain to be elucidated. Here, we found that the mRNA expression level of AIMP2-DX2 was significantly increased in NPC specimens, compared with normal nasopharyngeal tissues. Microarray immunohistochemical analysis of NPC specimens and Kaplan–Meier analysis showed that patients with high AIMP2-DX2 protein expression had shorter overall survival than those with low AIMP2-DX2 level. Furthermore, mRNA and protein expression levels of AIMP2-DX2 were both increased in cultured NPC cell lines (5-8F, CNE-2Z, and CNE-1), by being compared with normal nasopharyngeal cell line NP69. Overexpression of AIMP2-DX2 remarkably promoted the cell viability, cell migration, and invasion of cultured NPC cells. Genetic knockdown of AIMP2-DX2 by shRNA lentiviruses significantly suppressed the proliferation, migration, and invasion and induced apoptosis of NPC cells. Inhibition of AIMP2-DX2 decreased the highly expressed level of matrix metalloproteinase- (MMP-) 2 and MMP-9, further suppressed proliferation, migration, and invasion in cultured NPC cells in vitro, and inhibited tumor growth in a xenograft mouse model in vivo. Taken together, these results suggest that AIMP2-DX2 plays an important role in the regulation of NPC and could be a potential therapeutic target and prognostic indicator for the treatment of NPC.
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8
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HIV-1 Exploits a Dynamic Multi-aminoacyl-tRNA Synthetase Complex To Enhance Viral Replication. J Virol 2017; 91:JVI.01240-17. [PMID: 28814526 DOI: 10.1128/jvi.01240-17] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2017] [Accepted: 08/10/2017] [Indexed: 11/20/2022] Open
Abstract
A hallmark of retroviruses such as human immunodeficiency virus type 1 (HIV-1) is reverse transcription of genomic RNA to DNA, a process that is primed by cellular tRNAs. HIV-1 recruits human tRNALys3 to serve as the reverse transcription primer via an interaction between lysyl-tRNA synthetase (LysRS) and the HIV-1 Gag polyprotein. LysRS is normally sequestered in a multi-aminoacyl-tRNA synthetase complex (MSC). Previous studies demonstrated that components of the MSC can be mobilized in response to certain cellular stimuli, but how LysRS is redirected from the MSC to viral particles for packaging is unknown. Here, we show that upon HIV-1 infection, a free pool of non-MSC-associated LysRS is observed and partially relocalized to the nucleus. Heat inactivation of HIV-1 blocks nuclear localization of LysRS, but treatment with a reverse transcriptase inhibitor does not, suggesting that the trigger for relocalization occurs prior to reverse transcription. A reduction in HIV-1 infection is observed upon treatment with an inhibitor to mitogen-activated protein kinase that prevents phosphorylation of LysRS on Ser207, release of LysRS from the MSC, and nuclear localization. A phosphomimetic mutant of LysRS (S207D) that lacked the capability to aminoacylate tRNALys3 localized to the nucleus, rescued HIV-1 infectivity, and was packaged into virions. In contrast, a phosphoablative mutant (S207A) remained cytosolic and maintained full aminoacylation activity but failed to rescue infectivity and was not packaged. These findings suggest that HIV-1 takes advantage of the dynamic nature of the MSC to redirect and coopt cellular translation factors to enhance viral replication.IMPORTANCE Human tRNALys3, the primer for reverse transcription, and LysRS are essential host factors packaged into HIV-1 virions. Previous studies found that tRNALys3 packaging depends on interactions between LysRS and HIV-1 Gag; however, many details regarding the mechanism of tRNALys3 and LysRS packaging remain unknown. LysRS is normally sequestered in a high-molecular-weight multi-aminoacyl-tRNA synthetase complex (MSC), restricting the pool of free LysRS-tRNALys Mounting evidence suggests that LysRS is released under a variety of stimuli to perform alternative functions within the cell. Here, we show that HIV-1 infection results in a free pool of LysRS that is relocalized to the nucleus of target cells. Blocking this pathway in HIV-1-producing cells resulted in less infectious progeny virions. Understanding the mechanism by which LysRS is recruited into the viral assembly pathway can be exploited for the development of specific and effective therapeutics targeting this nontranslational function.
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Kim SB, Kim HR, Park MC, Cho S, Goughnour PC, Han D, Yoon I, Kim Y, Kang T, Song E, Kim P, Choi H, Mun JY, Song C, Lee S, Jung HS, Kim S. Caspase-8 controls the secretion of inflammatory lysyl-tRNA synthetase in exosomes from cancer cells. J Cell Biol 2017; 216:2201-2216. [PMID: 28611052 PMCID: PMC5496609 DOI: 10.1083/jcb.201605118] [Citation(s) in RCA: 69] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2016] [Revised: 10/05/2016] [Accepted: 05/04/2017] [Indexed: 12/20/2022] Open
Abstract
Aminoacyl-tRNA synthetases (ARSs), enzymes that normally control protein synthesis, can be secreted and have different activities in the extracellular space, but the mechanism of their secretion is not understood. This study describes the secretion route of the ARS lysyl-tRNA synthetase (KRS) and how this process is regulated by caspase activity, which has been implicated in the unconventional secretion of other proteins. We show that KRS is secreted from colorectal carcinoma cells within the lumen of exosomes that can trigger an inflammatory response. Caspase-8 cleaved the N-terminal of KRS, thus exposing a PDZ-binding motif located in the C terminus of KRS. Syntenin bound to the exposed PDZ-binding motif of KRS and facilitated the exosomic secretion of KRS dissociated from the multi-tRNA synthetase complex. KRS-containing exosomes released by cancer cells induced macrophage migration, and their secretion of TNF-α and cleaved KRS made a significant contribution to these activities, which suggests a novel mechanism by which caspase-8 may promote inflammation.
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Affiliation(s)
- Sang Bum Kim
- Medicinal Bioconvergence Research Center, Seoul National University, Suwon, South Korea.,Department of Molecular Medicine and Biopharmaceutical Sciences, Graduate School of Convergence Science and Technology, Seoul National University, Seoul, South Korea
| | - Hye Rim Kim
- Medicinal Bioconvergence Research Center, Seoul National University, Suwon, South Korea
| | - Min Chul Park
- Medicinal Bioconvergence Research Center, Seoul National University, Suwon, South Korea
| | - Seongmin Cho
- Medicinal Bioconvergence Research Center, Seoul National University, Suwon, South Korea.,Department of Molecular Medicine and Biopharmaceutical Sciences, Graduate School of Convergence Science and Technology, Seoul National University, Seoul, South Korea
| | - Peter C Goughnour
- Medicinal Bioconvergence Research Center, Seoul National University, Suwon, South Korea.,Department of Molecular Medicine and Biopharmaceutical Sciences, Graduate School of Convergence Science and Technology, Seoul National University, Seoul, South Korea
| | - Daeyoung Han
- Medicinal Bioconvergence Research Center, Seoul National University, Suwon, South Korea.,Department of Molecular Medicine and Biopharmaceutical Sciences, Graduate School of Convergence Science and Technology, Seoul National University, Seoul, South Korea
| | - Ina Yoon
- Medicinal Bioconvergence Research Center, Seoul National University, Suwon, South Korea
| | - YounHa Kim
- Medicinal Bioconvergence Research Center, Seoul National University, Suwon, South Korea.,Department of Molecular Medicine and Biopharmaceutical Sciences, Graduate School of Convergence Science and Technology, Seoul National University, Seoul, South Korea
| | - Taehee Kang
- Medicinal Bioconvergence Research Center, Seoul National University, Suwon, South Korea
| | - Eunjoo Song
- Graduate School of Nanoscience and Technology, Korea Advanced Institute of Science and Technology, Daejeon, South Korea
| | - Pilhan Kim
- Graduate School of Nanoscience and Technology, Korea Advanced Institute of Science and Technology, Daejeon, South Korea
| | - Hyosun Choi
- BK21 Plus Program, Department of Senior Healthcare, Graduate School, Eulji University, Daejeon, South Korea
| | - Ji Young Mun
- BK21 Plus Program, Department of Senior Healthcare, Graduate School, Eulji University, Daejeon, South Korea.,Department of Biomedical Laboratory Science, College of Health Sciences, Eulji University, Seongnam, South Korea
| | - Chihong Song
- National Institute for Physiological Sciences, Okazaki, Japan
| | - Sangmin Lee
- Department of Biochemistry, College of Natural Sciences, Kangwon National University, Chuncheon, South Korea
| | - Hyun Suk Jung
- Department of Biochemistry, College of Natural Sciences, Kangwon National University, Chuncheon, South Korea
| | - Sunghoon Kim
- Medicinal Bioconvergence Research Center, Seoul National University, Suwon, South Korea .,Department of Molecular Medicine and Biopharmaceutical Sciences, Graduate School of Convergence Science and Technology, Seoul National University, Seoul, South Korea
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Interaction of NS2 with AIMP2 facilitates the switch from ubiquitination to SUMOylation of M1 in influenza A virus-infected cells. J Virol 2014; 89:300-11. [PMID: 25320310 DOI: 10.1128/jvi.02170-14] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
UNLABELLED Influenza A viruses (IAVs) rely on host factors to support their life cycle, as viral proteins hijack or interact with cellular proteins to execute their functions. Identification and understanding of these factors would increase our knowledge of the molecular mechanisms manipulated by the viruses. In this study, we searched for novel binding partners of the influenza A virus NS2 protein, the nuclear export protein responsible for overcoming host range restriction, by a yeast two-hybrid screening assay and glutathione S-transferase-pulldown and coimmunoprecipitation assays and identified AIMP2, a potent tumor suppressor that usually functions to regulate protein stability, as one of the major NS2-binding candidates. We found that the presence of NS2 protected AIMP2 from ubiquitin-mediated degradation in NS2-transfected cells and AIMP2 functioned as a positive regulator of IAV replication. Interestingly, AIMP2 had no significant effect on NS2 but enhanced the stability of the matrix protein M1. Further, we provide evidence that AIMP2 recruitment switches the modification of M1 from ubiquitination to SUMOylation, which occurs on the same attachment site (K242) on M1 and thereby promotes M1-mediated viral ribonucleoprotein complex nuclear export to increase viral replication. Collectively, our results reveal a new mechanism of AIMP2 mediation of influenza virus replication. IMPORTANCE Although the ubiquitination of M1 during IAV infection has been observed, the precise modification site and the molecular consequences of this modification remain obscure. Here, we demonstrate for the first time that ubiquitin and SUMO compete for the same lysine (K242) on M1 and the interaction of NS2 with AIMP2 facilitates the switch of the M1 modification from ubiquitination to SUMOylation, thus increasing viral replication.
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11
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Characterization of the interaction between lysyl-tRNA synthetase and laminin receptor by NMR. FEBS Lett 2014; 588:2851-8. [DOI: 10.1016/j.febslet.2014.06.048] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2014] [Revised: 05/30/2014] [Accepted: 06/11/2014] [Indexed: 12/11/2022]
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12
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Pang YLJ, Poruri K, Martinis SA. tRNA synthetase: tRNA aminoacylation and beyond. WILEY INTERDISCIPLINARY REVIEWS-RNA 2014; 5:461-80. [PMID: 24706556 DOI: 10.1002/wrna.1224] [Citation(s) in RCA: 103] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/12/2010] [Revised: 01/14/2014] [Accepted: 02/06/2014] [Indexed: 01/20/2023]
Abstract
The aminoacyl-tRNA synthetases are prominently known for their classic function in the first step of protein synthesis, where they bear the responsibility of setting the genetic code. Each enzyme is exquisitely adapted to covalently link a single standard amino acid to its cognate set of tRNA isoacceptors. These ancient enzymes have evolved idiosyncratically to host alternate activities that go far beyond their aminoacylation role and impact a wide range of other metabolic pathways and cell signaling processes. The family of aminoacyl-tRNA synthetases has also been suggested as a remarkable scaffold to incorporate new domains that would drive evolution and the emergence of new organisms with more complex function. Because they are essential, the tRNA synthetases have served as pharmaceutical targets for drug and antibiotic development. The recent unfolding of novel important functions for this family of proteins offers new and promising pathways for therapeutic development to treat diverse human diseases.
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Affiliation(s)
- Yan Ling Joy Pang
- Department of Biochemistry, University of Illinois at Urbana, Urbana, IL, USA
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Motzik A, Nechushtan H, Foo SY, Razin E. Non-canonical roles of lysyl-tRNA synthetase in health and disease. Trends Mol Med 2013; 19:726-31. [DOI: 10.1016/j.molmed.2013.07.011] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2013] [Revised: 07/16/2013] [Accepted: 07/26/2013] [Indexed: 01/26/2023]
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14
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Liu S, Decker A, Howell M, Caperelli C, Tsang P. ¹H, ¹³C and ¹⁵N resonance assignment of the N-terminal domain of human lysyl aminoacyl tRNA synthetase. BIOMOLECULAR NMR ASSIGNMENTS 2013; 7:289-292. [PMID: 23065336 DOI: 10.1007/s12104-012-9430-x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/12/2012] [Accepted: 10/04/2012] [Indexed: 06/01/2023]
Abstract
Human lysyl aminoacyl tRNA synthetase (hLysRS) is integral to a variety of different functions ranging from protein biosynthesis, initiation of a proinflammatory response as well as signal transduction. Another important, non-canonical function of hLysRS is that it chaperones tRNA(Lys,3), the HIV-1 reverse transcription primer molecule into new HIV-1 particles. Since the N-terminal domain of hLysRS has been shown to be essential for such primer uptake, NMR studies of this domain are being conducted to obtain a better understanding of how hLysRS interacts with the primer tRNA. In order to study the RNA binding behavior of this domain, we are studying its complex with a fragment of the cognate tRNA corresponding to the tRNA anticodon loop. We report herein the backbone and side chain NMR resonance assignments of uniformly (15)N-, (13)C-labeled hLysRS N-terminal domain alone, as well as complexed to RNA.
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Affiliation(s)
- Sheng Liu
- Department of Chemistry, University of Cincinnati, 301 Clifton Court, Cincinnati, OH 45221-0172, USA
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15
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Jones CP, Saadatmand J, Kleiman L, Musier-Forsyth K. Molecular mimicry of human tRNALys anti-codon domain by HIV-1 RNA genome facilitates tRNA primer annealing. RNA (NEW YORK, N.Y.) 2013; 19:219-29. [PMID: 23264568 PMCID: PMC3543088 DOI: 10.1261/rna.036681.112] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/02/2012] [Accepted: 11/14/2012] [Indexed: 05/18/2023]
Abstract
The primer for initiating reverse transcription in human immunodeficiency virus type 1 (HIV-1) is tRNA(Lys3). Host cell tRNA(Lys) is selectively packaged into HIV-1 through a specific interaction between the major tRNA(Lys)-binding protein, human lysyl-tRNA synthetase (hLysRS), and the viral proteins Gag and GagPol. Annealing of the tRNA primer onto the complementary primer-binding site (PBS) in viral RNA is mediated by the nucleocapsid domain of Gag. The mechanism by which tRNA(Lys3) is targeted to the PBS and released from hLysRS prior to annealing is unknown. Here, we show that hLysRS specifically binds to a tRNA anti-codon-like element (TLE) in the HIV-1 genome, which mimics the anti-codon loop of tRNA(Lys) and is located proximal to the PBS. Mutation of the U-rich sequence within the TLE attenuates binding of hLysRS in vitro and reduces the amount of annealed tRNA(Lys3) in virions. Thus, LysRS binds specifically to the TLE, which is part of a larger LysRS binding domain in the viral RNA that includes elements of the Psi packaging signal. Our results suggest that HIV-1 uses molecular mimicry of the anti-codon of tRNA(Lys) to increase the efficiency of tRNA(Lys3) annealing to viral RNA.
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MESH Headings
- Base Pairing
- Electrophoretic Mobility Shift Assay
- Genome, Viral/genetics
- HIV Enhancer/genetics
- HIV-1/genetics
- HIV-1/physiology
- Humans
- Lysine-tRNA Ligase/genetics
- Lysine-tRNA Ligase/metabolism
- Molecular Mimicry
- Mutation
- Protein Structure, Tertiary
- RNA
- RNA, Transfer, Lys/chemistry
- RNA, Transfer, Lys/genetics
- RNA, Transfer, Lys/metabolism
- RNA, Viral/genetics
- RNA, Viral/metabolism
- Virus Assembly/genetics
- Virus Replication/genetics
- gag Gene Products, Human Immunodeficiency Virus/metabolism
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Affiliation(s)
- Christopher P. Jones
- Department of Chemistry and Biochemistry, Center for Retroviral Research, and Center for RNA Biology, The Ohio State University, Columbus, Ohio 43210, USA
| | - Jenan Saadatmand
- Lady Davis Institute for Medical Research, McGill AIDS Centre, Jewish General Hospital, Montreal, Quebec, Canada, H3T1E2
| | - Lawrence Kleiman
- Lady Davis Institute for Medical Research, McGill AIDS Centre, Jewish General Hospital, Montreal, Quebec, Canada, H3T1E2
| | - Karin Musier-Forsyth
- Department of Chemistry and Biochemistry, Center for Retroviral Research, and Center for RNA Biology, The Ohio State University, Columbus, Ohio 43210, USA
- Corresponding authorE-mail
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16
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Abstract
Although aminoacyl-tRNA synthetases (ARSs) and ARS-interacting multi-functional proteins (AIMPs) have long been recognized as housekeeping proteins, evidence indicating that they play a key role in regulating cancer is now accumulating. In this chapter we will review the conventional and non-conventional functions of ARSs and AIMPs with respect to carcinogenesis. First, we will address how ARSs and AIMPs are altered in terms of expression, mutation, splicing, and post-translational modifications. Second, the molecular mechanisms for ARSs' and AIMPs' involvement in the initiation, maintenance, and progress of carcinogenesis will be covered. Finally, we will introduce the development of therapeutic approaches that target ARSs and AIMPs with the goal of treating cancer.
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17
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Liu S, Howell M, Melby J, Tsang P. 1H, 13C and 15N resonance assignment of the anticodon binding domain of human lysyl aminoacyl tRNA synthetase. BIOMOLECULAR NMR ASSIGNMENTS 2012; 6:173-176. [PMID: 22105307 DOI: 10.1007/s12104-011-9349-7] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/19/2011] [Accepted: 11/09/2011] [Indexed: 05/31/2023]
Abstract
Human lysyl aminoacyl tRNA synthetase (hLysRS) is a multi-functional aminoacyl tRNA synthetase which is primarily involved in protein biosynthesis as well as crucial processes ranging from proinflammatory response to signal transduction. One important, non-canonical function of hLysRS is to target tRNA(Lys,3), the HIV-1 reverse transcription primer molecule, for uptake and packaging into new HIV-1 particles. Since the anticodon binding (ACB) domain of hLysRS is required for proper recognition of its cognate tRNA, NMR studies of the ACB domain are being conducted to enhance our understanding of how hLysRS interacts with these RNAs during protein biosysnthesis as well as HIV-1 viral packaging. Here, we report the backbone and side chain NMR resonance assignments of the uniformly (15)N-, (13)C-labeled ACB domain of hLysRS.
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Affiliation(s)
- Sheng Liu
- Department of Chemistry, University of Cincinnati, 301 Clifton Court, Cincinnati, OH 45221-0172, USA
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18
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Genome wide analysis reveals association of a FTO gene variant with epigenetic changes. Genomics 2012; 99:132-7. [PMID: 22234326 DOI: 10.1016/j.ygeno.2011.12.007] [Citation(s) in RCA: 118] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2011] [Revised: 12/16/2011] [Accepted: 12/22/2011] [Indexed: 11/23/2022]
Abstract
Variants of the FTO gene show strong association with obesity, but the mechanisms behind this association remain unclear. We determined the genome wide DNA methylation profile in blood from 47 female preadolescents. We identified sites associated with the genes KARS, TERF2IP, DEXI, MSI1, STON1 and BCAS3 that had a significant differential methylation level in the carriers of the FTO risk allele (rs9939609). In addition, we identified 20 differentially methylated sites associated with obesity. Our findings suggest that the effect of the FTO obesity risk allele may be mediated through epigenetic changes. Further, these sites might prove to be valuable biomarkers for the understanding of obesity and its comorbidites.
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19
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Abstract
Over the past decade, the identification of cancer-associated factors has been a subject of primary interest not only for understanding the basic mechanisms of tumorigenesis but also for discovering the associated therapeutic targets. However, aminoacyl-tRNA synthetases (ARSs) have been overlooked, mostly because many assumed that they were simply 'housekeepers' that were involved in protein synthesis. Mammalian ARSs have evolved many additional domains that are not necessarily linked to their catalytic activities. With these domains, they interact with diverse regulatory factors. In addition, the expression of some ARSs is dynamically changed depending on various cellular types and stresses. This Analysis article addresses the potential pathophysiological implications of ARSs in tumorigenesis.
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Affiliation(s)
- Sunghoon Kim
- Medicinal Bioconvergence Research Center, WCU Department of Molecular Medicine and Biopharmaceutical Sciences, Seoul National University, Seoul 151-742, Republic of Korea.
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20
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Structural context for mobilization of a human tRNA synthetase from its cytoplasmic complex. Proc Natl Acad Sci U S A 2011; 108:8239-44. [PMID: 21536907 DOI: 10.1073/pnas.1100224108] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Human lysyl-tRNA synthetase is bound to the multi-tRNA synthetase complex (MSC) that maintains and regulates the aminoacylation and nuclear functions of LysRS. The p38 scaffold protein binds LysRS to the MSC and, only with the appropriate cue, mobilizes LysRS for redirection to the nucleus to interact with the microphthalmia associated transcription factor (MITF). In recent work, an (α(2))(2) LysRS tetramer crystallized to yield a high-resolution structure and raised the question of how LysRS is arranged (dimer or tetramer) in the MSC to interact with p38. To understand the structural organization of the LysRS-p38 complex that regulates LysRS mobilization, we investigated the complex by use of small angle X-ray scattering and hydrogen-deuterium exchange with mass spectrometry in solution. The structure revealed a surprising α(2)β(1):β(1)α(2) organization in which a dimeric p38 scaffold holds two LysRS α(2) dimers in a parallel configuration. Each of the N-terminal 48 residues of p38 binds one LysRS dimer and, in so doing, brings two copies of the LysRS dimer into the MSC. The results suggest that this unique geometry, which reconfigures the LysRS tetramer from α(2):α(2) to α(2)β(1):β(1)α(2), is designed to control both retention and mobilization of LysRS from the MSC.
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21
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Bassaganya-Riera J, Guri AJ, Lu P, Climent M, Carbo A, Sobral BW, Horne WT, Lewis SN, Bevan DR, Hontecillas R. Abscisic acid regulates inflammation via ligand-binding domain-independent activation of peroxisome proliferator-activated receptor gamma. J Biol Chem 2011; 286:2504-16. [PMID: 21088297 PMCID: PMC3024745 DOI: 10.1074/jbc.m110.160077] [Citation(s) in RCA: 81] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2010] [Revised: 10/16/2010] [Indexed: 01/01/2023] Open
Abstract
Abscisic acid (ABA) has shown efficacy in the treatment of diabetes and inflammation; however, its molecular targets and the mechanisms of action underlying its immunomodulatory effects remain unclear. This study investigates the role of peroxisome proliferator-activated receptor γ (PPAR γ) and lanthionine synthetase C-like 2 (LANCL2) as molecular targets for ABA. We demonstrate that ABA increases PPAR γ reporter activity in RAW 264.7 macrophages and increases ppar γ expression in vivo, although it does not bind to the ligand-binding domain of PPAR γ. LANCL2 knockdown studies provide evidence that ABA-mediated activation of macrophage PPAR γ is dependent on lancl2 expression. Consistent with the association of LANCL2 with G proteins, we provide evidence that ABA increases cAMP accumulation in immune cells. ABA suppresses LPS-induced prostaglandin E(2) and MCP-1 production via a PPAR γ-dependent mechanism possibly involving activation of PPAR γ and suppression of NF-κB and nuclear factor of activated T cells. LPS challenge studies in PPAR γ-expressing and immune cell-specific PPAR γ null mice demonstrate that ABA down-regulates toll-like receptor 4 expression in macrophages and T cells in vivo through a PPAR γ-dependent mechanism. Global transcriptomic profiling and confirmatory quantitative RT-PCR suggest novel candidate targets and demonstrate that ABA treatment mitigates the effect of LPS on the expression of genes involved in inflammation, metabolism, and cell signaling, in part, through PPAR γ. In conclusion, ABA decreases LPS-mediated inflammation and regulates innate immune responses through a bifurcating pathway involving LANCL2 and an alternative, ligand-binding domain-independent mechanism of PPAR γ activation.
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Affiliation(s)
- Josep Bassaganya-Riera
- From the Nutritional Immunology and Molecular Medicine Group, Virginia Bioinformatics Institute and
| | - Amir J. Guri
- From the Nutritional Immunology and Molecular Medicine Group, Virginia Bioinformatics Institute and
| | - Pinyi Lu
- From the Nutritional Immunology and Molecular Medicine Group, Virginia Bioinformatics Institute and
| | - Montse Climent
- From the Nutritional Immunology and Molecular Medicine Group, Virginia Bioinformatics Institute and
| | - Adria Carbo
- From the Nutritional Immunology and Molecular Medicine Group, Virginia Bioinformatics Institute and
| | - Bruno W. Sobral
- From the Nutritional Immunology and Molecular Medicine Group, Virginia Bioinformatics Institute and
| | - William T. Horne
- From the Nutritional Immunology and Molecular Medicine Group, Virginia Bioinformatics Institute and
| | - Stephanie N. Lewis
- From the Nutritional Immunology and Molecular Medicine Group, Virginia Bioinformatics Institute and
- Department of Biochemistry, Virginia Polytechnic Institute and State University, Blacksburg, Virginia 24061
| | - David R. Bevan
- Department of Biochemistry, Virginia Polytechnic Institute and State University, Blacksburg, Virginia 24061
| | - Raquel Hontecillas
- From the Nutritional Immunology and Molecular Medicine Group, Virginia Bioinformatics Institute and
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22
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Tshori S, Nechushtan H. Mast cell transcription factors--regulators of cell fate and phenotype. Biochim Biophys Acta Mol Basis Dis 2011; 1822:42-8. [PMID: 21236338 DOI: 10.1016/j.bbadis.2010.12.024] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2010] [Revised: 12/16/2010] [Accepted: 12/30/2010] [Indexed: 10/18/2022]
Abstract
Transcription factors have a key role in mast cell differentiation and response of differentiated mast cells to external stimuli. During differentiation of progenitor cells to mast cells, a role for different GATA transcription factors in combination with PU.1 expression and downregulation of C/EBPα has been described. Notch pathway has been proposed to have a role in mast cell development. The microphthalmia-associated transcription factor expression is upregulated in later stages of mast cells differentiation, but it is not expressed in the closely related basophiles. In differentiated mast cells, there is a role for transcription factors both in determining the specific mast cell phenotype and in the response to immune stimuli such as IgE-Ag. A large number of transcription factors, including AP-1 family proteins, microphthalmia-associated transcription factor and STAT5, are modulated by these stimuli. These transcription factors and related protein modulators form a complex transcription factor network. They can form stimuli regulated specific heterodimers and common inhibitors can move from one protein to another. Transcription factors are the key regulators of mast cell physiology. Modulation of key transcription by such means as the therapeutic siRNA may hopefully allow us to modulate mast cell function, obtaining clinical benefit in a variety of diseases. This article is part of a Special Issue entitled: Mast cells in inflammation.
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Affiliation(s)
- Sagi Tshori
- Department of Medical Biophysics and Nuclear Medicine, Hadassah-Hebrew University Medical Center, P.O. Box 12000, Jerusalem, 91120, Israel
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23
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Guo M, Shapiro R, Morris GM, Yang XL, Schimmel P. Packaging HIV virion components through dynamic equilibria of a human tRNA synthetase. J Phys Chem B 2010; 114:16273-9. [PMID: 21058683 DOI: 10.1021/jp1082517] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
Aminoacyl tRNA synthetases, components of the translation apparatus, have alternative functions outside of translation. The structural and mechanistic basis of these alternative functions is of great interest. As an example, reverse transcription of the HIV genome is primed by a human lysine-specific tRNA (tRNA(Lys3)) that is packaged (into the virion) by the HIV Gag protein with lysyl-tRNA synthetase (LysRS). Not understood is the structural basis for simultaneous packaging of tRNA(Lys3), LysRS, and Gag. Here, ab initio computational methods, together with our recent high-resolution 3-D structure of human LysRS, produced an energy-minimized model where Gag, tRNA(Lys), and LysRS form a ternary complex. Interestingly, the model requires normally homodimeric LysRS to dissociate into a monomer that bridges between Gag and tRNA(Lys3). Earlier experiments of others and new experiments presented here, which tested an engineered dissociated form of LysRS, were consistent with the ab initio "bridging monomer" model. The results support an emerging theme that alterative functions of tRNA synthetases may come, in part, from protein surfaces exposed by dynamic equilibria.
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Affiliation(s)
- Min Guo
- The Skaggs Institute for Chemical Biology, 10550 North Torrey Pines Road, La Jolla, California 92037, United States
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