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Licon MH, Yates PA. Purine-responsive expression of the Leishmania donovani NT3 purine nucleobase transporter is mediated by a conserved RNA stem-loop. J Biol Chem 2020; 295:8449-8459. [PMID: 32354744 PMCID: PMC7307198 DOI: 10.1074/jbc.ra120.012696] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2020] [Revised: 04/28/2020] [Indexed: 01/17/2023] Open
Abstract
The ability to modulate gene expression in response to changes in the host environment is essential for survival of the kinetoplastid parasite Leishmania Unlike most eukaryotes, gene expression in kinetoplastids is predominately regulated posttranscriptionally. Consequently, RNA-binding proteins and mRNA-encoded sequence elements serve as primary determinants of gene regulation in these organisms; however, few have defined roles in specific stress response pathways. Leishmania species cannot synthesize purines de novo and must scavenge these essential nutrients from the host. Leishmania have evolved a robust stress response to withstand sustained periods of purine scarcity during their life cycle. The purine nucleobase transporter LdNT3 is among the most substantially up-regulated proteins in purine-starved Leishmania donovani parasites. Here we report that the posttranslational stability of the LdNT3 protein is unchanged in response to purine starvation. Instead, LdNT3 up-regulation is primarily mediated by a 33-nucleotide-long sequence in the LdNT3 mRNA 3' UTR that is predicted to adopt a stem-loop structure. Although this sequence is highly conserved within the mRNAs of orthologous transporters in multiple kinetoplastid species, putative stem-loops from L. donovani and Trypanosoma brucei nucleobase transporter mRNAs were not functionally interchangeable for purine-responsive regulation. Through mutational analysis of the element, we demonstrate that species specificity is attributable to just three variant bases within the predicted loop. Finally, we provide evidence that the abundance of the trans-acting factor that binds the LdNT3 stem-loop in vivo is substantially higher than required for regulation of LdNT3 alone, implying a potential role in regulating other purine-responsive genes.
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Affiliation(s)
- M Haley Licon
- Department of Molecular Microbiology, Oregon Health & Science University, Portland, Oregon, USA
| | - Phillip A Yates
- Department of Chemical Physiology and Biochemistry, Oregon Health & Science University, Portland, Oregon, USA
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3
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Dong L, Hou X, Liu F, Tao H, Zhang Y, Zhao H, Song G. Regulation of insulin resistance by targeting the insulin-like growth factor 1 receptor with microRNA-122-5p in hepatic cells. Cell Biol Int 2019; 43:553-564. [PMID: 30958584 DOI: 10.1002/cbin.11129] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2018] [Accepted: 03/16/2019] [Indexed: 12/15/2022]
Abstract
Insulin resistance (IR) is a common etiology of type 2 diabetes (T2D) defined by a state of decreased reactivity to insulin in multiple organs, such as the liver. This study aims to investigate how microRNA-122-5p (miR-122) regulates the hepatic IR in vitro. We first found that the miR-122 level was upregulated in the liver of rats fed with a high-fat diet and injected with streptozotocin (T2D rats), while the expression level of insulin-like growth factor 1 receptor (IGF-1R), a potential target of miR-122, was downregulated in the diabetic liver. In vitro, glucosamine-induced IR was introduced in HepG2 hepatic cells, and the levels of miR-122 and IGF-1R were further assessed. An increase of miR-122 level and a decrease of IGF-IR level were observed in IR hepatic cells, which was the same as that in the diabetic liver. Results of the luciferase reporter assay validated IGF-1R as a direct target of miR-122. Moreover, in IR HepG2 cells, antagonizing miR-122 with its specific inhibitor enhanced glucose uptake and suppressed the expression of glucose 6-phosphatase and phosphoenolpyruvate carboxykinase, two key enzymes in regulating gluconeogenesis. Such alterations induced by the miR-122 inhibitor in IR hepatic cells were impaired when IGF-1R was simultaneously knocked down. In addition, the PI3K/Akt pathway was deactivated in IR cells, and then reactivated with miR-122 inhibitor transfection. In conclusion, our study demonstrates that miR-122 is able to regulate IR in hepatic cells by targeting IGF-1R.
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Affiliation(s)
- Li Dong
- Department of Internal Medicine, Hebei Medical University, Shijiazhuang, 050017, Hebei, People's Republic of China.,Key Laboratory of Metabolic Diseases of Hebei Province, Hebei Medical University, Shijiazhuang, 050017, Hebei, People's Republic of China.,Department of Critical Care Medicine, First Hospital of Qinhuangdao, Qinhuangdao, 066001, Hebei, People's Republic of China
| | - Xiaoyu Hou
- Department of Internal Medicine, Hebei Medical University, Shijiazhuang, 050017, Hebei, People's Republic of China.,Key Laboratory of Metabolic Diseases of Hebei Province, Hebei Medical University, Shijiazhuang, 050017, Hebei, People's Republic of China
| | - Fengsui Liu
- Department of Critical Care Medicine, First Hospital of Qinhuangdao, Qinhuangdao, 066001, Hebei, People's Republic of China
| | - Hong Tao
- Department of Critical Care Medicine, Qinhuangdao Hospital of Traditional Chinese Medicine, Qinhuangdao, 066006, Hebei, People's Republic of China
| | - Yunjia Zhang
- Department of Internal Medicine, Hebei Medical University, Shijiazhuang, 050017, Hebei, People's Republic of China.,Key Laboratory of Metabolic Diseases of Hebei Province, Hebei Medical University, Shijiazhuang, 050017, Hebei, People's Republic of China
| | - Hang Zhao
- Department of Internal Medicine, Hebei Medical University, Shijiazhuang, 050017, Hebei, People's Republic of China.,Key Laboratory of Metabolic Diseases of Hebei Province, Hebei Medical University, Shijiazhuang, 050017, Hebei, People's Republic of China
| | - Guangyao Song
- Department of Internal Medicine, Hebei Medical University, Shijiazhuang, 050017, Hebei, People's Republic of China.,Department of Endocrinology, Hebei General Hospital, Shijiazhuang, 050051, Hebei, People's Republic of China
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4
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Benz C, Lo W, Fathallah N, Connor-Guscott A, Benns HJ, Urbaniak MD. Dynamic regulation of the Trypanosoma brucei transferrin receptor in response to iron starvation is mediated via the 3'UTR. PLoS One 2018; 13:e0206332. [PMID: 30596656 PMCID: PMC6312234 DOI: 10.1371/journal.pone.0206332] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2018] [Accepted: 12/14/2018] [Indexed: 12/04/2022] Open
Abstract
The bloodstream form of the parasite Trypanosoma brucei obtains iron from its mammalian host by receptor-mediated endocytosis of host transferrin through its own unique transferrin receptor (TbTfR). Expression of TbTfR rapidly increases upon iron starvation by post-transcriptional regulation through a currently undefined mechanism that is distinct from the mammalian iron response system. We have created reporter cell lines by fusing the TbTfR 3’UTR or a control Aldolase 3’UTR to reporter genes encoding GFP or firefly Luciferase, and inserted the fusions into a bloodstream form cell line at a tagged ribosomal RNA locus. Fusion of the TbTfR 3’UTR is sufficient to significantly repress the expression of the reporter proteins under normal growth conditions. Under iron starvation conditions we observed upregulation of the mRNA and protein level of the TbTfR 3’UTR fusions only, with a magnitude and timing consistent with that reported for upregulation of the TbTfR. We conclude that the dynamic regulation of the T. brucei transferrin receptor in response to iron starvation is mediated via its 3’UTR, and that the effect is independent of genomic location.
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Affiliation(s)
- Corinna Benz
- Biomedical and Life Sciences, Faculty of Health and Medicine, Lancaster University, Lancaster, United Kingdom
| | - Winston Lo
- Biomedical and Life Sciences, Faculty of Health and Medicine, Lancaster University, Lancaster, United Kingdom
| | - Nadin Fathallah
- Biomedical and Life Sciences, Faculty of Health and Medicine, Lancaster University, Lancaster, United Kingdom
| | - Ashley Connor-Guscott
- Biomedical and Life Sciences, Faculty of Health and Medicine, Lancaster University, Lancaster, United Kingdom
| | - Henry J. Benns
- Biomedical and Life Sciences, Faculty of Health and Medicine, Lancaster University, Lancaster, United Kingdom
| | - Michael D. Urbaniak
- Biomedical and Life Sciences, Faculty of Health and Medicine, Lancaster University, Lancaster, United Kingdom
- * E-mail:
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5
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Soysa R, Tran KD, Ullman B, Yates PA. Integrating ribosomal promoter vectors that offer a choice of constitutive expression profiles in Leishmania donovani. Mol Biochem Parasitol 2016; 204:89-92. [PMID: 26844641 DOI: 10.1016/j.molbiopara.2016.01.008] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2015] [Revised: 01/05/2016] [Accepted: 01/28/2016] [Indexed: 12/17/2022]
Abstract
We have designed a novel series of integrating ribosomal RNA promoter vectors with five incrementally different constitutive expression profiles, covering a 250-fold range. Differential expression was achieved by placing different combinations of synthetic or leishmanial DNA sequences upstream and downstream of the transgene coding sequence in order to modulate pre-mRNA processing efficiency and mRNA stability, respectively. All of the vectors have extensive multiple cloning sites, and versions are available for producing N- or C- terminal GFP fusions at each of the possible relative expression levels. In addition, the modular configuration of the vectors allows drug resistance cassettes and other components to be readily exchanged. In toto, these vectors should be useful additions to the toolkit available for molecular and genetic studies of Leishmania donovani.
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Affiliation(s)
- Radika Soysa
- Department of Biochemistry and Molecular Biology, Oregon Health & Science University, Portland, OR 97239, USA
| | - Khoa D Tran
- Department of Molecular Microbiology and Immunology, Oregon Health & Science University, Portland, OR 97239, USA
| | - Buddy Ullman
- Department of Biochemistry and Molecular Biology, Oregon Health & Science University, Portland, OR 97239, USA
| | - Phillip A Yates
- Department of Biochemistry and Molecular Biology, Oregon Health & Science University, Portland, OR 97239, USA.
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6
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Sun L, Zheng J, Wang Q, Song R, Liu H, Meng R, Tao T, Si Y, Jiang W, He J. NHERF1 regulates actin cytoskeleton organization through modulation of α-actinin-4 stability. FASEB J 2015; 30:578-89. [PMID: 26432781 DOI: 10.1096/fj.15-275586] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2015] [Accepted: 09/21/2015] [Indexed: 01/12/2023]
Abstract
The actin cytoskeleton is composed of a highly dynamic network of filamentous proteins, yet the molecular mechanism that regulates its organization and remodeling remains elusive. In this study, Na(+)/H(+) exchanger regulatory factor (NHERF)-1 loss-of-function and gain-of-function experiments reveal that polymerized actin cytoskeleton (F-actin) in HeLa cells is disorganized by NHERF1, whereas actin protein expression levels exhibit no detectable change. To elucidate the molecular mechanism underlying actin cytoskeleton disorganization by NHERF1, a combined 2-dimensional electrophoresis-matrix-assisted laser desorption/ionization-time of flight mass spectrometry approach was used to screen for proteins regulated by NHERF1 in HeLa cells. α-Actinin-4, an actin cross-linking protein, was identified. Glutathione S-transferase pull-down and coimmunoprecipitation studies showed the α-actinin-4 carboxyl-terminal region specifically interacted with the NHERF1 postsynaptic density 95/disc-large/zona occludens-1 domain. The NHERF1/α-actinin-4 interaction increased α-actinin-4 ubiquitination and decreased its expression levels, resulting in actin cytoskeleton disassembly. Our study identified α-actinin-4 as a novel NHERF1 interaction partner and provided new insights into the regulatory mechanism of the actin cytoskeleton by NHERF1.
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Affiliation(s)
- Licui Sun
- *Department of Biochemistry and Molecular Biology, Capital Medical University, Beijing, China; Beijing Key Laboratory for Tumor Invasion and Metastasis, Capital Medical University-Cardiff University Joint Centre for Biomedical Research, Cancer Institute of Capital Medical University, Beijing, China; and Metastasis and Angiogenesis Research Group, Department of Surgery, Cardiff University School of Medicine, Heath Park, Cardiff, United Kingdom
| | - Junfang Zheng
- *Department of Biochemistry and Molecular Biology, Capital Medical University, Beijing, China; Beijing Key Laboratory for Tumor Invasion and Metastasis, Capital Medical University-Cardiff University Joint Centre for Biomedical Research, Cancer Institute of Capital Medical University, Beijing, China; and Metastasis and Angiogenesis Research Group, Department of Surgery, Cardiff University School of Medicine, Heath Park, Cardiff, United Kingdom
| | - Qiqi Wang
- *Department of Biochemistry and Molecular Biology, Capital Medical University, Beijing, China; Beijing Key Laboratory for Tumor Invasion and Metastasis, Capital Medical University-Cardiff University Joint Centre for Biomedical Research, Cancer Institute of Capital Medical University, Beijing, China; and Metastasis and Angiogenesis Research Group, Department of Surgery, Cardiff University School of Medicine, Heath Park, Cardiff, United Kingdom
| | - Ran Song
- *Department of Biochemistry and Molecular Biology, Capital Medical University, Beijing, China; Beijing Key Laboratory for Tumor Invasion and Metastasis, Capital Medical University-Cardiff University Joint Centre for Biomedical Research, Cancer Institute of Capital Medical University, Beijing, China; and Metastasis and Angiogenesis Research Group, Department of Surgery, Cardiff University School of Medicine, Heath Park, Cardiff, United Kingdom
| | - Hua Liu
- *Department of Biochemistry and Molecular Biology, Capital Medical University, Beijing, China; Beijing Key Laboratory for Tumor Invasion and Metastasis, Capital Medical University-Cardiff University Joint Centre for Biomedical Research, Cancer Institute of Capital Medical University, Beijing, China; and Metastasis and Angiogenesis Research Group, Department of Surgery, Cardiff University School of Medicine, Heath Park, Cardiff, United Kingdom
| | - Ran Meng
- *Department of Biochemistry and Molecular Biology, Capital Medical University, Beijing, China; Beijing Key Laboratory for Tumor Invasion and Metastasis, Capital Medical University-Cardiff University Joint Centre for Biomedical Research, Cancer Institute of Capital Medical University, Beijing, China; and Metastasis and Angiogenesis Research Group, Department of Surgery, Cardiff University School of Medicine, Heath Park, Cardiff, United Kingdom
| | - Tao Tao
- *Department of Biochemistry and Molecular Biology, Capital Medical University, Beijing, China; Beijing Key Laboratory for Tumor Invasion and Metastasis, Capital Medical University-Cardiff University Joint Centre for Biomedical Research, Cancer Institute of Capital Medical University, Beijing, China; and Metastasis and Angiogenesis Research Group, Department of Surgery, Cardiff University School of Medicine, Heath Park, Cardiff, United Kingdom
| | - Yang Si
- *Department of Biochemistry and Molecular Biology, Capital Medical University, Beijing, China; Beijing Key Laboratory for Tumor Invasion and Metastasis, Capital Medical University-Cardiff University Joint Centre for Biomedical Research, Cancer Institute of Capital Medical University, Beijing, China; and Metastasis and Angiogenesis Research Group, Department of Surgery, Cardiff University School of Medicine, Heath Park, Cardiff, United Kingdom
| | - Wenguo Jiang
- *Department of Biochemistry and Molecular Biology, Capital Medical University, Beijing, China; Beijing Key Laboratory for Tumor Invasion and Metastasis, Capital Medical University-Cardiff University Joint Centre for Biomedical Research, Cancer Institute of Capital Medical University, Beijing, China; and Metastasis and Angiogenesis Research Group, Department of Surgery, Cardiff University School of Medicine, Heath Park, Cardiff, United Kingdom
| | - Junqi He
- *Department of Biochemistry and Molecular Biology, Capital Medical University, Beijing, China; Beijing Key Laboratory for Tumor Invasion and Metastasis, Capital Medical University-Cardiff University Joint Centre for Biomedical Research, Cancer Institute of Capital Medical University, Beijing, China; and Metastasis and Angiogenesis Research Group, Department of Surgery, Cardiff University School of Medicine, Heath Park, Cardiff, United Kingdom
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7
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Cantacessi C, Dantas-Torres F, Nolan MJ, Otranto D. The past, present, and future of Leishmania genomics and transcriptomics. Trends Parasitol 2015; 31:100-8. [PMID: 25638444 PMCID: PMC4356521 DOI: 10.1016/j.pt.2014.12.012] [Citation(s) in RCA: 65] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2014] [Revised: 12/22/2014] [Accepted: 12/22/2014] [Indexed: 01/31/2023]
Abstract
It has been nearly 10 years since the completion of the first entire genome sequence of a Leishmania parasite. Genomic and transcriptomic analyses have advanced our understanding of the biology of Leishmania, and shed new light on the complex interactions occurring within the parasite-host-vector triangle. Here, we review these advances and examine potential avenues for translation of these discoveries into treatment and control programs. In addition, we argue for a strong need to explore how disease in dogs relates to that in humans, and how an improved understanding in line with the 'One Health' concept may open new avenues for the control of these devastating diseases.
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Affiliation(s)
- Cinzia Cantacessi
- Department of Veterinary Medicine, University of Cambridge, Cambridge, UK.
| | - Filipe Dantas-Torres
- Departamento de Imunologia, Centro de Pesquisas Aggeu Magalhães, Fiocruz-PE, Brazil; Dipartimento di Medicina Veterinaria, Università degli Studi di Bari, Bari, Italy
| | - Matthew J Nolan
- Royal Veterinary College, University of London, North Mymms, UK
| | - Domenico Otranto
- Dipartimento di Medicina Veterinaria, Università degli Studi di Bari, Bari, Italy
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