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Yang Q, Wang J, Chen Z. Conditional splicing system for tight control of viral overlapping genes. J Virol 2024; 98:e0024224. [PMID: 38446633 PMCID: PMC11019872 DOI: 10.1128/jvi.00242-24] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2024] [Accepted: 02/11/2024] [Indexed: 03/08/2024] Open
Abstract
Viral genomes frequently harbor overlapping genes, complicating the development of virus-vectored vaccines and gene therapies. This study introduces a novel conditional splicing system to precisely control the expression of such overlapping genes through recombinase-mediated conditional splicing. We refined site-specific recombinase (SSR) conditional splicing systems and explored their mechanisms. The systems demonstrated exceptional inducibility (116,700-fold increase) with negligible background expression, facilitating the conditional expression of overlapping genes in adenovirus-associated virus (AAV) and human immunodeficiency virus type 1. Notably, this approach enabled the establishment of stable AAV producer cell lines, encapsulating all necessary packaging genes. Our findings underscore the potential of the SSR-conditional splicing system to significantly advance vector engineering, enhancing the efficacy and scalability of viral-vector-based therapies and vaccines. IMPORTANCE Regulating overlapping genes is vital for gene therapy and vaccine development using viral vectors. The regulation of overlapping genes presents challenges, including cytotoxicity and impacts on vector capacity and genome stability, which restrict stable packaging cell line development and broad application. To address these challenges, we present a "loxp-splice-loxp"-based conditional splicing system, offering a novel solution for conditional expression of overlapping genes and stable cell line establishment. This system may also regulate other cytotoxic genes, representing a significant advancement in cell engineering and gene therapy as well as biomass production.
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Affiliation(s)
- Qing Yang
- AIDS Institute and Department of Microbiology, School of Clinical Medicine, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong Special Administrative Region, People's Republic of China
| | - Jinlin Wang
- AIDS Institute and Department of Microbiology, School of Clinical Medicine, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong Special Administrative Region, People's Republic of China
| | - Zhiwei Chen
- AIDS Institute and Department of Microbiology, School of Clinical Medicine, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong Special Administrative Region, People's Republic of China
- State Key Laboratory of Emerging Infectious Diseases, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong Special Administrative Region, People's Republic of China
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Kim DH, Yang J, Ha SH, Kim JK, Lee JY, Lim SH. An OsKala3, R2R3 MYB TF, Is a Common Key Player for Black Rice Pericarp as Main Partner of an OsKala4, bHLH TF. Front Plant Sci 2021; 12:765049. [PMID: 34777449 PMCID: PMC8585765 DOI: 10.3389/fpls.2021.765049] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/27/2021] [Accepted: 10/04/2021] [Indexed: 05/27/2023]
Abstract
Rice (Oryza sativa) pericarp exhibits various colors due to the accumulation of anthocyanins and/or proanthocyanidins. Previous work revealed that the two basic helix-loop-helix (bHLH) transcription factors OsKala4 and OsRc are key regulators for the black and red pericarp traits, respectively, and their inactivation results in rice with white pericarp. However, their pericarp-specific R2R3 MYB partner remained unknown. Here, we characterized the role of the R2R3 MYB gene OsKala3 in rice pericarp pigmentation through genetic and molecular approaches. A rice protoplast transfection assay showed that OsKala3 is a nuclear-localized protein. Furthermore, OsKala3 physically interacted with OsKala4 in a yeast two-hybrid analysis. Co-transfection assays in rice protoplasts revealed that OsKala3 and OsKala4 mediate the activation of anthocyanin biosynthetic genes. Notably, the OsKala3 promoter region exhibited an insertion polymorphism specifically in rice cultivars with black pericarp, creating two tandem repeats while red and white varieties harbor only one. The number of repeats within the OsKala3 promoter correlated with increased transactivation by OsKala3, thus providing a rationale for the black pericarp characteristic of cultivars with two repeats. These results thus provide evidence for the molecular basis of anthocyanin biosynthesis in rice pericarp and may facilitate the introduction of this beneficial trait to other rice cultivars through marker-assisted breeding.
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Affiliation(s)
- Da-Hye Kim
- Division of Horticultural Biotechnology, School of Biotechnology, Hankyong National University, Anseong, South Korea
- National Academy of Agricultural Science, Rural Development Administration, Jeonju, South Korea
| | - JuHee Yang
- National Academy of Agricultural Science, Rural Development Administration, Jeonju, South Korea
| | - Sun-Hwa Ha
- Department of Genetic Engineering, Graduate School of Biotechnology, Kyung Hee University, Yongin, South Korea
| | - Jae Kwang Kim
- Division of Life Sciences, Bio-Resource and Environmental Center, Incheon National University, Incheon, South Korea
| | - Jong-Yeol Lee
- National Academy of Agricultural Science, Rural Development Administration, Jeonju, South Korea
| | - Sun-Hyung Lim
- Division of Horticultural Biotechnology, School of Biotechnology, Hankyong National University, Anseong, South Korea
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Zheng J, Wu H, Zhu H, Huang C, Liu C, Chang Y, Kong Z, Zhou Z, Wang G, Lin Y, Chen H. Determining factors, regulation system, and domestication of anthocyanin biosynthesis in rice leaves. New Phytol 2019; 223:705-721. [PMID: 30891753 DOI: 10.1111/nph.15807] [Citation(s) in RCA: 68] [Impact Index Per Article: 13.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/12/2018] [Accepted: 03/10/2019] [Indexed: 05/11/2023]
Abstract
Wild and cultivated rice show a significant difference in anthocyanin biosynthesis in the leaf. The regulation system of anthocyanin biosynthesis in rice leaf and the causal mechanism of the difference in this biosynthesis between wild and cultivated rice remain largely unknown. In this study, a genome-wide association study and transcriptome analysis were performed to identify the determinant factors and dissect the regulatory system for anthocyanin biosynthesis in rice leaves. OsC1, OsRb and OsDFR were identified as the determinants of anthocyanin biosynthesis in rice leaves. Artificial selection of certain null mutations of OsC1 and OsRb was the main causal mechanism underlying the loss of anthocyanin pigmentation in most cultivated rice. OsP1 and the MYB-bHLH-WD40 complexes regulate anthocyanin biosynthetic genes in rice leaves with partial functional overlap. OsP1 specifically activates upstream biosynthetic genes (OsCHS, OsCHI and OsF3'H) for anthocyanin biosynthesis, whereas the ternary MYB-bHLH-WD40 complex activates all anthocyanin biosynthetic genes including OsCHS, OsCHI, OsF3'H, OsF3H, OsDFR and OsANS. OsC1 and OsRb are tissue-specific regulators that do not influence anthocyanin biosynthesis in the pericarp. Our results reveal the determinant factors, regulatory system and domestication of anthocyanin biosynthesis in rice leaves, and show the potential of engineering anthocyanin biosynthesis in rice.
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Affiliation(s)
- Jie Zheng
- National Key Laboratory of Crop Genetic Improvement and National Center of Plant Gene Research (Wuhan), Huazhong Agricultural University, Wuhan, 430070, China
| | - Hao Wu
- National Key Laboratory of Crop Genetic Improvement and National Center of Plant Gene Research (Wuhan), Huazhong Agricultural University, Wuhan, 430070, China
| | - Huabing Zhu
- National Key Laboratory of Crop Genetic Improvement and National Center of Plant Gene Research (Wuhan), Huazhong Agricultural University, Wuhan, 430070, China
| | - Changyuan Huang
- National Key Laboratory of Crop Genetic Improvement and National Center of Plant Gene Research (Wuhan), Huazhong Agricultural University, Wuhan, 430070, China
| | - Chang Liu
- National Key Laboratory of Crop Genetic Improvement and National Center of Plant Gene Research (Wuhan), Huazhong Agricultural University, Wuhan, 430070, China
| | - Yongsheng Chang
- National Key Laboratory of Crop Genetic Improvement and National Center of Plant Gene Research (Wuhan), Huazhong Agricultural University, Wuhan, 430070, China
| | - Zichun Kong
- National Key Laboratory of Crop Genetic Improvement and National Center of Plant Gene Research (Wuhan), Huazhong Agricultural University, Wuhan, 430070, China
| | - Zaihui Zhou
- National Key Laboratory of Crop Genetic Improvement and National Center of Plant Gene Research (Wuhan), Huazhong Agricultural University, Wuhan, 430070, China
| | - Gongwei Wang
- National Key Laboratory of Crop Genetic Improvement and National Center of Plant Gene Research (Wuhan), Huazhong Agricultural University, Wuhan, 430070, China
| | - Yongjun Lin
- National Key Laboratory of Crop Genetic Improvement and National Center of Plant Gene Research (Wuhan), Huazhong Agricultural University, Wuhan, 430070, China
| | - Hao Chen
- National Key Laboratory of Crop Genetic Improvement and National Center of Plant Gene Research (Wuhan), Huazhong Agricultural University, Wuhan, 430070, China
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Blach-Olszewska Z, Leszek J. Mechanisms of over-activated innate immune system regulation in autoimmune and neurodegenerative disorders. Neuropsychiatr Dis Treat 2007; 3:365-72. [PMID: 19300567 PMCID: PMC2654796] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
Reactions of innate immunity include phagocytosis, the production and activity of cytokines, chemokines, and adhesion molecules, the killing of infected or changed cells by NK cells and complement activated by natural lectins, and the cytokine-dependent resistance of leukocytes to viral infection. All these mechanisms maintain innate immunity. Deficiency in this immunity is sometimes accompanied by frequent bacterial and viral infections. When innate immunity is permanently stimulated and the intensity of the reactions is stronger, these mechanisms may be directed against the host and subsequently stimulate acquired immunity (antibody and cellular immunity). A higher production of cytokines, oxidative stress, and a high production of NO accompany autoimmunity and neurodegeneration. The possible participation of innate immune receptors, cytokines, and other factors in the development of autoimmune and neurodegenerative diseases is discussed. The importance and possible role of blood-derived microglial cells in the prevention or elimination of amyloid deposits and plaque formation is described. A possible regulatory system, based on the presence of suppressors of cytokine signaling (SOCS), receptors of the Tyro-3 family, adenosine and adenosine phosphates, and IL-10, is reviewed. This review presents the mechanisms involved in the control of the innate immune response by microglia in the development of neurodegenerative disorders.
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Affiliation(s)
- Zofia Blach-Olszewska
- Institute of Immunology and Experimental Therapy Polish Academy of Sciences, Wrocław, Poland
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