1
|
Balbin JM, Heinemann GK, Yeoh LM, Gilberger TW, Armstrong M, Duffy MF, Gilson PR, Wilson DW. Characterisation of PfCZIF1 and PfCZIF2 in Plasmodium falciparum asexual stages. Int J Parasitol 2023; 53:27-41. [PMID: 36400305 DOI: 10.1016/j.ijpara.2022.09.008] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2022] [Revised: 08/30/2022] [Accepted: 09/25/2022] [Indexed: 11/17/2022]
Abstract
Plasmodium falciparum exerts strong temporal control of gene expression across its lifecycle. Proteins expressed exclusively during late schizogony of blood stages, for example, often have a role in facilitating merozoite invasion of the host red blood cell (RBC), through merozoite development, egress, invasion or early establishment of infection in the RBC. Here, we characterise P. falciparum C3H1 zinc finger 1 (PfCZIF1, Pf3D7_1468400) and P. falciparum C3H1 zinc finger 2 (PfCZIF2, Pf3D7_0818100) which we identified as the only C3H1-type zinc finger proteins with peak expression at schizogony. Previous studies reported that antibodies against PfCZIF1 inhibit merozoite invasion, suggesting this protein may have a potential role during RBC invasion. We show using C-terminal truncations and gene knockouts of each of Pfczif1 and Pfczif2 that neither are essential for blood stage growth. However, they could not both be knocked out simultaneously, suggesting that at least one is needed for parasite growth in vitro. Immunofluorescence localisation of PfCZIF1 and PfCZIF2 indicated that both proteins occur in discrete foci on the periphery of the parasite's cytosol and biochemical assays suggest they are peripherally associated to a membrane. Transcriptomic analyses for the C-terminal truncation mutants reveal no significant expression perturbations with PfCZIF1 truncation. However, modification of PfCZIF2 appears to modify the expression for some exported proteins including PfKAHRP. This study does not support a role for PfCZIF1 or PfCZIF2 in merozoite invasion of the RBC and suggests that these proteins may help regulate the expression of proteins exported into the RBC cytosol after merozoite invasion.
Collapse
Affiliation(s)
- Juan M Balbin
- Research Centre for Infectious Diseases, School of Biological Sciences, University of Adelaide, Adelaide 5005, Australia. https://twitter.com/jmiguel_balbin
| | - Gary K Heinemann
- Experimental Therapeutics Laboratory, Clinical and Health Science Unit, University of South Australia, Adelaide, SA 5000, Australia
| | - Lee M Yeoh
- Burnet Institute, Melbourne 3004, Victoria, Australia; Department of Biochemistry and Molecular Biology, Bio21 Molecular Science and Biotechnology Institute, The University of Melbourne, Melbourne 3010, Victoria, Australia
| | - Tim-Wolf Gilberger
- Centre for Structural Systems Biology, 22607 Hamburg, Germany; Bernhard Nocht Institute for Tropical Medicine, 20359 Hamburg, Germany; University of Hamburg, 20146 Hamburg, Germany
| | | | - Michael F Duffy
- Department of Biochemistry and Molecular Biology, Bio21 Molecular Science and Biotechnology Institute, The University of Melbourne, Melbourne 3010, Victoria, Australia
| | - Paul R Gilson
- Burnet Institute, Melbourne 3004, Victoria, Australia; Department of Microbiology and Immunology, The University of Melbourne, Melbourne 3010, Victoria, Australia
| | - Danny W Wilson
- Research Centre for Infectious Diseases, School of Biological Sciences, University of Adelaide, Adelaide 5005, Australia; Burnet Institute, Melbourne 3004, Victoria, Australia; Institute for Photonics and Advanced Sensing (IPAS), University of Adelaide, 5005 SA, Australia.
| |
Collapse
|
2
|
Qadir MI, Bashir H, Ahmad MH. Human Oropharyngeal Candidiasis: From Etiology to Current Treatment. Crit Rev Immunol 2023; 43:15-24. [PMID: 37824374 DOI: 10.1615/critrevimmunol.2023049730] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/14/2023]
Abstract
Oral candidiasis is a common but most harmful oral cavity infection caused by yeast-like fungus, this condition is called Oropharyngeal candidiasis. There are various species of candida that are responsible for oral cavity fungal infection including mostly Candida albicans. Different candida infections may be acute and chronic. Cell-mediated immunity, humoral immunity, and granulocytes are the immune factors for the cause of this infection. Different antifungal drugs like nystatin, fluconazole, and amphotericin are used to treat oral cavity fungal infections.
Collapse
Affiliation(s)
- Muhammad Imran Qadir
- Institute of Molecular Biology & Biotechnology, Bahauddin Zakariya University, Multan, Pakistan
| | - Hina Bashir
- Institute of Molecular Biology and Biotechnology, Bahauddin Zakaria University, Multan, Pakistan
| | - Muhammad Hammad Ahmad
- Institute of Molecular Biology and Biotechnology, Bahauddin Zakariya University, Multan, Pakistan
| |
Collapse
|
3
|
Snyder BL, Blackshear PJ. Clinical implications of tristetraprolin (TTP) modulation in the treatment of inflammatory diseases. Pharmacol Ther 2022; 239:108198. [PMID: 35525391 PMCID: PMC9636069 DOI: 10.1016/j.pharmthera.2022.108198] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2022] [Revised: 04/19/2022] [Accepted: 04/25/2022] [Indexed: 11/24/2022]
Abstract
Abnormal regulation of pro-inflammatory cytokine and chemokine mediators can contribute to the excess inflammation characteristic of many autoimmune diseases, such as rheumatoid arthritis, psoriasis, Crohn's disease, type 1 diabetes, and many others. The tristetraprolin (TTP) family consists of a small group of related RNA-binding proteins that bind to preferred AU-rich binding sites within the 3'-untranslated regions of specific mRNAs to promote mRNA deadenylation and decay. TTP deficient mice develop a severe systemic inflammatory syndrome consisting of arthritis, myeloid hyperplasia, dermatitis, autoimmunity and cachexia, due at least in part to the excess accumulation of proinflammatory chemokine and cytokine mRNAs and their encoded proteins. To investigate the possibility that increased TTP expression or activity might have a beneficial effect on inflammatory diseases, at least two mouse models have been developed that provide proof of principle that increasing TTP activity can promote the decay of pro-inflammatory and other relevant transcripts, and decrease the severity of mouse models of inflammatory disease. Animal studies of this type are summarized here, and we briefly review the prospects for harnessing these insights for the development of TTP-based anti-inflammatory treatments in humans.
Collapse
Affiliation(s)
- Brittany L Snyder
- Signal Transduction Laboratory, National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, NC 27709, United States of America; Department of Biochemistry, Duke University Medical Center, Durham, NC 27710, United States of America
| | - Perry J Blackshear
- Signal Transduction Laboratory, National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, NC 27709, United States of America; Department of Medicine, Duke University Medical Center, Durham, NC 27710, United States of America; Department of Biochemistry, Duke University Medical Center, Durham, NC 27710, United States of America.
| |
Collapse
|
4
|
Bai W, Wells ML, Lai WS, Hicks SN, Burkholder AB, Perera L, Kimmel AR, Blackshear PJ. A post-transcriptional regulon controlled by TtpA, the single tristetraprolin family member expressed in Dictyostelium discoideum. Nucleic Acids Res 2021; 49:11920-11937. [PMID: 34718768 DOI: 10.1093/nar/gkab983] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2021] [Revised: 10/05/2021] [Accepted: 10/12/2021] [Indexed: 12/30/2022] Open
Abstract
Post-transcriptional processes mediated by mRNA binding proteins represent important control points in gene expression. In eukaryotes, mRNAs containing specific AU-rich motifs are regulated by binding of tristetraprolin (TTP) family tandem zinc finger proteins, which promote mRNA deadenylation and decay, partly through interaction of a conserved C-terminal CNOT1 binding (CNB) domain with CCR4-NOT protein complexes. The social ameba Dictyostelium discoideum shared a common ancestor with humans more than a billion years ago, and expresses only one TTP family protein, TtpA, in contrast to three members expressed in humans. Evaluation of ttpA null-mutants identified six transcripts that were consistently upregulated compared to WT during growth and early development. The 3'-untranslated regions (3'-UTRs) of all six 'TtpA-target' mRNAs contained multiple TTP binding motifs (UUAUUUAUU), and one 3'-UTR conferred TtpA post-transcriptional stability regulation to a heterologous mRNA that was abrogated by mutations in the core TTP-binding motifs. All six target transcripts were upregulated to similar extents in a C-terminal truncation mutant, in contrast to less severe effects of analogous mutants in mice. All six target transcripts encoded probable membrane proteins. In Dictyostelium, TtpA may control an 'RNA regulon', where a single RNA binding protein, TtpA, post-transcriptionally co-regulates expression of several functionally related proteins.
Collapse
Affiliation(s)
- Wenli Bai
- Laboratory of Cellular and Developmental Biology, National Institute of Diabetes and Digestive and Kidney Diseases, Bethesda, MD 20892, USA
| | - Melissa L Wells
- The Signal Transduction Laboratory, National Institute of Environmental Health Sciences, Research Triangle Park, NC 27709, USA
| | - Wi S Lai
- The Signal Transduction Laboratory, National Institute of Environmental Health Sciences, Research Triangle Park, NC 27709, USA
| | - Stephanie N Hicks
- The Signal Transduction Laboratory, National Institute of Environmental Health Sciences, Research Triangle Park, NC 27709, USA
| | - Adam B Burkholder
- Integrative Bioinformatics Support Group, National Institute of Environmental Health Sciences, Research Triangle Park, NC 27709, USA
| | - Lalith Perera
- Genome Integrity and Structural Biology Laboratory, National Institute of Environmental Health Sciences, Research Triangle Park, NC 27709, USA
| | - Alan R Kimmel
- Laboratory of Cellular and Developmental Biology, National Institute of Diabetes and Digestive and Kidney Diseases, Bethesda, MD 20892, USA
| | - Perry J Blackshear
- The Signal Transduction Laboratory, National Institute of Environmental Health Sciences, Research Triangle Park, NC 27709, USA.,The Departments of Medicine and Biochemistry, Duke University Medical Center, Durham, NC 27710, USA
| |
Collapse
|
5
|
Rana A, Gupta N, Thakur A. Post-transcriptional and translational control of the morphology and virulence in human fungal pathogens. Mol Aspects Med 2021; 81:101017. [PMID: 34497025 DOI: 10.1016/j.mam.2021.101017] [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: 02/11/2021] [Revised: 08/13/2021] [Accepted: 08/20/2021] [Indexed: 11/17/2022]
Abstract
Host-pathogen interactions at the molecular level are the key to fungal pathogenesis. Fungal pathogens utilize several mechanisms such as adhesion, invasion, phenotype switching and metabolic adaptations, to survive in the host environment and respond. Post-transcriptional and translational regulations have emerged as key regulatory mechanisms ensuring the virulence and survival of fungal pathogens. Through these regulations, fungal pathogens effectively alter their protein pool, respond to various stress, and undergo morphogenesis, leading to efficient and comprehensive changes in fungal physiology. The regulation of virulence through post-transcriptional and translational regulatory mechanisms is mediated through mRNA elements (cis factors) or effector molecules (trans factors). The untranslated regions upstream and downstream of the mRNA, as well as various RNA-binding proteins involved in translation initiation or circularization of the mRNA, play pivotal roles in the regulation of morphology and virulence by influencing protein synthesis, protein isoforms, and mRNA stability. Therefore, post-transcriptional and translational mechanisms regulating the morphology, virulence and drug-resistance processes in fungal pathogens can be the target for new therapeutics. With improved "omics" technologies, these regulatory mechanisms are increasingly coming to the forefront of basic biology and drug discovery. This review aims to discuss various modes of post-transcriptional and translation regulations, and how these mechanisms exert influence in the virulence and morphogenesis of fungal pathogens.
Collapse
Affiliation(s)
- Aishwarya Rana
- Regional Centre for Biotechnology, 3rd Milestone Gurgaon-Faridabad Expressway, Faridabad 121001, India
| | - Nidhi Gupta
- Regional Centre for Biotechnology, 3rd Milestone Gurgaon-Faridabad Expressway, Faridabad 121001, India
| | - Anil Thakur
- Regional Centre for Biotechnology, 3rd Milestone Gurgaon-Faridabad Expressway, Faridabad 121001, India.
| |
Collapse
|
6
|
Martínez-Pastor MT, Puig S. Adaptation to iron deficiency in human pathogenic fungi. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2020; 1867:118797. [PMID: 32663505 DOI: 10.1016/j.bbamcr.2020.118797] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/24/2020] [Revised: 06/13/2020] [Accepted: 07/05/2020] [Indexed: 02/08/2023]
Abstract
Iron is an essential micronutrient for virtually all eukaryotic organisms and plays a central role during microbial infections. Invasive fungal diseases are associated with strikingly high rates of mortality, but their impact on human health is usually underestimated. Upon a fungal infection, hosts restrict iron availability in order to limit the growth and virulence of the pathogen. Here, we use two model yeasts, Saccharomyces cerevisiae and Schizosaccharomyces pombe, to delve into the response to iron deficiency of human fungal pathogens, such as Candida glabrata, Candida albicans, Aspergillus fumigatus and Cryptococcus neoformans. Fungi possess common and species-specific mechanisms to acquire iron and to control the response to iron limitation. Upon iron scarcity, fungi activate a wide range of elegant strategies to capture and import exogenous iron, mobilize iron from intracellular stores, and modulate their metabolism to economize and prioritize iron utilization. Hence, iron homeostasis genes represent remarkable virulence factors that can be used as targets for the development of novel antifungal treatments.
Collapse
Affiliation(s)
| | - Sergi Puig
- Departamento de Biotecnología, Instituto de Agroquímica y Tecnología de Alimentos (IATA), Consejo Superior de Investigaciones Científicas (CSIC), Paterna, Valencia, Spain.
| |
Collapse
|
7
|
Devaux F, Thiébaut A. The regulation of iron homeostasis in the fungal human pathogen Candida glabrata. MICROBIOLOGY-SGM 2019; 165:1041-1060. [PMID: 31050635 DOI: 10.1099/mic.0.000807] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Iron is an essential element to most microorganisms, yet an excess of iron is toxic. Hence, living cells have to maintain a tight balance between iron uptake and iron consumption and storage. The control of intracellular iron concentrations is particularly challenging for pathogens because mammalian organisms have evolved sophisticated high-affinity systems to sequester iron from microbes and because iron availability fluctuates among the different host niches. In this review, we present the current understanding of iron homeostasis and its regulation in the fungal pathogen Candida glabrata. This yeast is an emerging pathogen which has become the second leading cause of candidemia, a life-threatening invasive mycosis. C. glabrata is relatively poorly studied compared to the closely related model yeast Saccharomyces cerevisiae or to the pathogenic yeast Candida albicans. Still, several research groups have started to identify the actors of C. glabrata iron homeostasis and its transcriptional and post-transcriptional regulation. These studies have revealed interesting particularities of C. glabrata and have shed new light on the evolution of fungal iron homeostasis.
Collapse
Affiliation(s)
- Frédéric Devaux
- Sorbonne Université, CNRS, Institut de Biologie Paris-Seine, Laboratory of Computational and Quantitative Biology, F-75005, Paris, France
| | - Antonin Thiébaut
- Sorbonne Université, CNRS, Institut de Biologie Paris-Seine, Laboratory of Computational and Quantitative Biology, F-75005, Paris, France
| |
Collapse
|
8
|
Lai WS, Wells ML, Perera L, Blackshear PJ. The tandem zinc finger RNA binding domain of members of the tristetraprolin protein family. WILEY INTERDISCIPLINARY REVIEWS-RNA 2019; 10:e1531. [PMID: 30864256 DOI: 10.1002/wrna.1531] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/28/2018] [Revised: 02/12/2019] [Accepted: 02/20/2019] [Indexed: 12/23/2022]
Abstract
Tristetraprolin (TTP), the prototype member of the protein family of the same name, was originally discovered as the product of a rapidly inducible gene in mouse cells. Development of a knockout (KO) mouse established that absence of the protein led to a severe inflammatory syndrome, due in part to elevated levels of tumor necrosis factor (TNF). TTP was found to bind directly and with high affinity to specific AU-rich sequences in the 3'-untranslated region of the TNF mRNA. This initial binding led to promotion of TNF mRNA decay and inhibition of its translation. Many additional TTP target mRNAs have since been identified, some of which are cytokines and chemokines involved in the inflammatory response. There are three other proteins in the mouse with similar activities and domain structures, but whose KO phenotypes are remarkably different. Moreover, proteins with similar domain structures and activities have been found throughout eukaryotes, demonstrating that this protein family arose from an ancient ancestor. The defining characteristic of this protein family is the tandem zinc finger (TZF) domain, a 64 amino acid sequence with many conserved residues that is responsible for the direct RNA binding. We discuss here many aspects of this protein domain that have been elucidated since the original discovery of TTP, including its sequence conservation throughout eukarya; its apparent continued evolution in some lineages; its functional dependence on many key conserved residues; its "interchangeability" among evolutionarily distant species; and the evidence that RNA binding is required for the physiological functions of the proteins. This article is categorized under: RNA Interactions with Proteins and Other Molecules > RNA-Protein Complexes RNA Interactions with Proteins and Other Molecules > Protein-RNA Recognition RNA Interactions with Proteins and Other Molecules > Protein-RNA Interactions: Functional Implications.
Collapse
Affiliation(s)
- Wi S Lai
- Signal Transduction Laboratory, National Institute of Environmental Health Sciences, Durham, North Carolina
| | - Melissa L Wells
- Signal Transduction Laboratory, National Institute of Environmental Health Sciences, Durham, North Carolina
| | - Lalith Perera
- Genome Integrity and Structural Biology Laboratory, National Institute of Environmental Health Sciences, Durham, North Carolina
| | - Perry J Blackshear
- Signal Transduction Laboratory, National Institute of Environmental Health Sciences, Durham, North Carolina.,Departments of Medicine and Biochemistry, Duke University Medical Center, Durham, North Carolina
| |
Collapse
|
9
|
The 5' Untranslated Region of the EFG1 Transcript Promotes Its Translation To Regulate Hyphal Morphogenesis in Candida albicans. mSphere 2018; 3:3/4/e00280-18. [PMID: 29976646 PMCID: PMC6034079 DOI: 10.1128/msphere.00280-18] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
Extensive 5' untranslated regions (UTR) are a hallmark of transcripts determining hyphal morphogenesis in Candida albicans The major transcripts of the EFG1 gene, which are responsible for cellular morphogenesis and metabolism, contain a 5' UTR of up to 1,170 nucleotides (nt). Deletion analyses of the 5' UTR revealed a 218-nt sequence that is required for production of the Efg1 protein and its functions in filamentation, without lowering the level and integrity of the EFG1 transcript. Polysomal analyses revealed that the 218-nt 5' UTR sequence is required for efficient translation of the Efg1 protein. Replacement of the EFG1 open reading frame (ORF) by the heterologous reporter gene CaCBGluc confirmed the positive regulatory importance of the identified 5' UTR sequence. In contrast to other reported transcripts containing extensive 5' UTR sequences, these results indicate the positive translational function of the 5' UTR sequence in the EFG1 transcript, which is observed in the context of the native EFG1 promoter. It is proposed that the 5' UTR recruits regulatory factors, possibly during emergence of the native transcript, which aid in translation of the EFG1 transcript.IMPORTANCE Many of the virulence traits that make Candida albicans an important human fungal pathogen are regulated on a transcriptional level. Here, we report an important regulatory contribution of translation, which is exerted by the extensive 5' untranslated regulatory sequence (5' UTR) of the transcript for the protein Efg1, which determines growth, metabolism, and filamentation in the fungus. The presence of the 5' UTR is required for efficient translation of Efg1, to promote filamentation. Because transcripts for many relevant regulators contain extensive 5' UTR sequences, it appears that the virulence of C. albicans depends on the combination of transcriptional and translational regulatory mechanisms.
Collapse
|
10
|
de Toeuf B, Soin R, Nazih A, Dragojevic M, Jurėnas D, Delacourt N, Vo Ngoc L, Garcia-Pino A, Kruys V, Gueydan C. ARE-mediated decay controls gene expression and cellular metabolism upon oxygen variations. Sci Rep 2018; 8:5211. [PMID: 29581565 PMCID: PMC5980108 DOI: 10.1038/s41598-018-23551-8] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2017] [Accepted: 03/14/2018] [Indexed: 12/18/2022] Open
Abstract
Hypoxia triggers profound modifications of cellular transcriptional programs. Upon reoxygenation, cells return to a normoxic gene expression pattern and mRNA produced during the hypoxic phase are degraded. TIS11 proteins control deadenylation and decay of transcripts containing AU-rich elements (AREs). We observed that the level of dTIS11 is decreased in hypoxic S2 Drosophila cells and returns to normal level upon reoxygenation. Bioinformatic analyses using the ARE-assessing algorithm AREScore show that the hypoxic S2 transcriptome is enriched in ARE-containing transcripts and that this trend is conserved in human myeloid cells. Moreover, an efficient down-regulation of Drosophila ARE-containing transcripts during hypoxia/normoxia transition requires dtis11 expression. Several of these genes encode proteins with metabolic functions. Here, we show that ImpL3 coding for Lactate Dehydrogenase in Drosophila, is regulated by ARE-mediated decay (AMD) with dTIS11 contributing to ImpL3 rapid down-regulation upon return to normal oxygen levels after hypoxia. More generally, we observed that dtis11 expression contributes to cell metabolic and proliferative recovery upon reoxygenation. Altogether, our data demonstrate that AMD plays an important role in the control of gene expression upon variation in oxygen concentration and contributes to optimal metabolic adaptation to oxygen variations.
Collapse
Affiliation(s)
- Bérengère de Toeuf
- Laboratoire de Biologie Moléculaire du Gène, Faculté des Sciences, Université libre de Bruxelles (ULB), 12 rue des Profs. Jeener et Brachet, 6041, Gosselies, Belgium
| | - Romuald Soin
- Laboratoire de Biologie Moléculaire du Gène, Faculté des Sciences, Université libre de Bruxelles (ULB), 12 rue des Profs. Jeener et Brachet, 6041, Gosselies, Belgium
| | - Abdelkarim Nazih
- Laboratoire de Biologie Moléculaire du Gène, Faculté des Sciences, Université libre de Bruxelles (ULB), 12 rue des Profs. Jeener et Brachet, 6041, Gosselies, Belgium
| | - Marija Dragojevic
- Laboratoire de Biologie Moléculaire du Gène, Faculté des Sciences, Université libre de Bruxelles (ULB), 12 rue des Profs. Jeener et Brachet, 6041, Gosselies, Belgium
| | - Dukas Jurėnas
- Laboratoire de Microbiologie Moléculaire et Cellulaire, Faculté des Sciences, Université libre de Bruxelles (ULB), 12 rue des Profs. Jeener et Brachet, 6041, Gosselies, Belgium
| | - Nadège Delacourt
- Laboratoire de Biologie Moléculaire du Gène, Faculté des Sciences, Université libre de Bruxelles (ULB), 12 rue des Profs. Jeener et Brachet, 6041, Gosselies, Belgium
| | - Long Vo Ngoc
- Laboratoire de Biologie Moléculaire du Gène, Faculté des Sciences, Université libre de Bruxelles (ULB), 12 rue des Profs. Jeener et Brachet, 6041, Gosselies, Belgium
- Section of Molecular Biology, University of California at San Diego, La Jolla, California, 92093, USA
| | - Abel Garcia-Pino
- Laboratoire de Microbiologie Moléculaire et Cellulaire, Faculté des Sciences, Université libre de Bruxelles (ULB), 12 rue des Profs. Jeener et Brachet, 6041, Gosselies, Belgium
| | - Véronique Kruys
- Laboratoire de Biologie Moléculaire du Gène, Faculté des Sciences, Université libre de Bruxelles (ULB), 12 rue des Profs. Jeener et Brachet, 6041, Gosselies, Belgium
| | - Cyril Gueydan
- Laboratoire de Biologie Moléculaire du Gène, Faculté des Sciences, Université libre de Bruxelles (ULB), 12 rue des Profs. Jeener et Brachet, 6041, Gosselies, Belgium.
| |
Collapse
|
11
|
Gerwien F, Skrahina V, Kasper L, Hube B, Brunke S. Metals in fungal virulence. FEMS Microbiol Rev 2018; 42:4562650. [PMID: 29069482 PMCID: PMC5812535 DOI: 10.1093/femsre/fux050] [Citation(s) in RCA: 142] [Impact Index Per Article: 23.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2017] [Accepted: 10/19/2017] [Indexed: 12/25/2022] Open
Abstract
Metals are essential for life, and they play a central role in the struggle between infecting microbes and their hosts. In fact, an important aspect of microbial pathogenesis is the 'nutritional immunity', in which metals are actively restricted (or, in an extended definition of the term, locally enriched) by the host to hinder microbial growth and virulence. Consequently, fungi have evolved often complex regulatory networks, uptake and detoxification systems for essential metals such as iron, zinc, copper, nickel and manganese. These systems often differ fundamentally from their bacterial counterparts, but even within the fungal pathogens we can find common and unique solutions to maintain metal homeostasis. Thus, we here compare the common and species-specific mechanisms used for different metals among different fungal species-focusing on important human pathogens such as Candida albicans, Aspergillus fumigatus or Cryptococcus neoformans, but also looking at model fungi such as Saccharomyces cerevisiae or A. nidulans as well-studied examples for the underlying principles. These direct comparisons of our current knowledge reveal that we have a good understanding how model fungal pathogens take up iron or zinc, but that much is still to learn about other metals and specific adaptations of individual species-not the least to exploit this knowledge for new antifungal strategies.
Collapse
Affiliation(s)
- Franziska Gerwien
- Department Microbial Pathogenicity Mechanisms, Leibniz Institute for Natural Product Research and Infection Biology– Hans Knoell Institute, 07745 Jena, Germany
| | - Volha Skrahina
- Department Microbial Pathogenicity Mechanisms, Leibniz Institute for Natural Product Research and Infection Biology– Hans Knoell Institute, 07745 Jena, Germany
| | - Lydia Kasper
- Department Microbial Pathogenicity Mechanisms, Leibniz Institute for Natural Product Research and Infection Biology– Hans Knoell Institute, 07745 Jena, Germany
| | - Bernhard Hube
- Department Microbial Pathogenicity Mechanisms, Leibniz Institute for Natural Product Research and Infection Biology– Hans Knoell Institute, 07745 Jena, Germany
| | - Sascha Brunke
- Department Microbial Pathogenicity Mechanisms, Leibniz Institute for Natural Product Research and Infection Biology– Hans Knoell Institute, 07745 Jena, Germany
| |
Collapse
|
12
|
Wells ML, Perera L, Blackshear PJ. An Ancient Family of RNA-Binding Proteins: Still Important! Trends Biochem Sci 2017; 42:285-296. [PMID: 28096055 DOI: 10.1016/j.tibs.2016.12.003] [Citation(s) in RCA: 45] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2016] [Revised: 12/08/2016] [Accepted: 12/09/2016] [Indexed: 12/22/2022]
Abstract
RNA-binding proteins are important modulators of mRNA stability, a crucial process that determines the ultimate cellular levels of mRNAs and their encoded proteins. The tristetraprolin (TTP) family of RNA-binding proteins appeared early in the evolution of eukaryotes, and has persisted in modern eukaryotes. The domain structures and biochemical functions of family members from widely divergent lineages are remarkably similar, but their mRNA 'targets' can be very different, even in closely related species. Recent gene knockout studies in species as distantly related as plants, flies, yeasts, and mice have demonstrated crucial roles for these proteins in a wide variety of physiological processes. Inflammatory and hematopoietic phenotypes in mice have suggested potential therapeutic approaches for analogous human disorders.
Collapse
Affiliation(s)
- Melissa L Wells
- Signal Transduction Laboratory, National Institute of Environmental Health Sciences, Research Triangle Park, NC 27709, USA
| | - Lalith Perera
- Genome Integrity and Structural Biology Laboratory, National Institute of Environmental Health Sciences, Research Triangle Park, NC 27709, USA
| | - Perry J Blackshear
- Signal Transduction Laboratory, National Institute of Environmental Health Sciences, Research Triangle Park, NC 27709, USA; Departments of Biochemistry and Medicine, Duke University Medical Center, Durham, NC 27710, USA.
| |
Collapse
|
13
|
Kadosh D. Control of Candida albicans morphology and pathogenicity by post-transcriptional mechanisms. Cell Mol Life Sci 2016; 73:4265-4278. [PMID: 27312239 PMCID: PMC5582595 DOI: 10.1007/s00018-016-2294-y] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2016] [Revised: 05/23/2016] [Accepted: 06/10/2016] [Indexed: 02/01/2023]
Abstract
Candida albicans is a major human fungal pathogen responsible for both systemic and mucosal infections in a wide variety of immunocompromised individuals. Because the ability of C. albicans to undergo a reversible morphological transition from yeast to filaments is important for virulence, significant research efforts have focused on mechanisms that control this transition. While transcriptional and post-translational mechanisms have been well-studied, considerably less is known about the role of post-transcriptional mechanisms. However, in recent years several discoveries have begun to shed light on this important, but understudied, area. Here, I will review a variety of post-transcriptional mechanisms that have recently been shown to control C. albicans morphology, virulence and/or virulence-related processes, including those involving alternative transcript localization, mRNA stability and translation. I will also discuss the role that these mechanisms play in other pathogens as well as the potential they may hold to serve as targets for new antifungal strategies. Ultimately, gaining a better understanding of C. albicans post-transcriptional mechanisms will significantly improve our knowledge of how morphogenesis and virulence are controlled in fungal pathogens and open new avenues for the development of novel and more effective antifungals.
Collapse
Affiliation(s)
- David Kadosh
- Department of Microbiology and Immunology, University of Texas Health Science, Center at San Antonio, 7703 Floyd Curl Drive, MC: 7758, San Antonio, TX, 78229, USA.
| |
Collapse
|
14
|
A Novel Hybrid Iron Regulation Network Combines Features from Pathogenic and Nonpathogenic Yeasts. mBio 2016; 7:mBio.01782-16. [PMID: 27795405 PMCID: PMC5082906 DOI: 10.1128/mbio.01782-16] [Citation(s) in RCA: 35] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Iron is an essential micronutrient for both pathogens and their hosts, which restrict iron availability during infections in an effort to prevent microbial growth. Successful human pathogens like the yeast Candida glabrata have thus developed effective iron acquisition strategies. Their regulation has been investigated well for some pathogenic fungi and in the model organism Saccharomyces cerevisiae, which employs an evolutionarily derived system. Here, we show that C. glabrata uses a regulation network largely consisting of components of the S. cerevisiae regulon but also of elements of other pathogenic fungi. Specifically, similarly to baker's yeast, Aft1 is the main positive regulator under iron starvation conditions, while Cth2 degrades mRNAs encoding iron-requiring enzymes. However, unlike the case with S. cerevisiae, a Sef1 ortholog is required for full growth under iron limitation conditions, making C. glabrata an evolutionary intermediate to SEF1-dependent fungal pathogens. Therefore, C. glabrata has evolved an iron homeostasis system which seems to be unique within the pathogenic fungi. IMPORTANCE The fungus Candida glabrata represents an evolutionarily close relative of the well-studied and benign baker's yeast and model organism Saccharomyces cerevisiae On the other hand, C. glabrata is an important opportunistic human pathogen causing both superficial and systemic infections. The ability to acquire trace metals, in particular, iron, and to tightly regulate this process during infection is considered an important virulence attribute of a variety of pathogens. Importantly, S. cerevisiae uses a highly derivative regulatory system distinct from those of other fungi. Until now, the regulatory mechanism of iron homeostasis in C. glabrata has been mostly unknown. Our study revealed a hybrid iron regulation network that is unique to C. glabrata and is placed at an evolutionary midpoint between those of S. cerevisiae and related fungal pathogens. We thereby show that, in the host, even a successful human pathogen can rely largely on a strategy normally found in nonpathogenic fungi from a terrestrial environment.
Collapse
|
15
|
Abstract
Candida albicans is a fungal species that is part of the normal human microbiota and also an opportunistic pathogen capable of causing mucosal and systemic infections. C. albicans cells proliferate in a planktonic (suspension) state, but they also form biofilms, organized and tightly packed communities of cells attached to a solid surface. Biofilms colonize many niches of the human body and persist on implanted medical devices, where they are a major source of new C. albicans infections. Here, we used an unbiased and global substrate-profiling approach to discover proteolytic activities produced specifically by C. albicans biofilms, compared to planktonic cells, with the goal of identifying potential biofilm-specific diagnostic markers and targets for therapeutic intervention. This activity-based profiling approach, coupled with proteomics, identified Sap5 (Candidapepsin-5) and Sap6 (Candidapepsin-6) as major biofilm-specific proteases secreted by C. albicans. Fluorogenic peptide substrates with selectivity for Sap5 or Sap6 confirmed that their activities are highly upregulated in C. albicans biofilms; we also show that these activities are upregulated in other Candida clade pathogens. Deletion of the SAP5 and SAP6 genes in C. albicans compromised biofilm development in vitro in standard biofilm assays and in vivo in a rat central venous catheter biofilm model. This work establishes secreted proteolysis as a promising enzymatic marker and potential therapeutic target for Candida biofilm formation. Biofilm formation by the opportunistic fungal pathogen C. albicans is a major cause of life-threatening infections. This work provides a global characterization of secreted proteolytic activity produced specifically by C. albicans biofilms. We identify activity from the proteases Sap5 and Sap6 as highly upregulated during C. albicans biofilm formation and develop Sap-cleavable fluorogenic substrates that enable the detection of biofilms from C. albicans and also from additional pathogenic Candida species. Furthermore, SAP5 and SAP6 deletions confirm that both proteases are required for proper biofilm development in vitro and in vivo. We propose that secreted proteolysis is a promising marker for the diagnosis and potential therapeutic targeting of Candida biofilm-associated infections.
Collapse
|
16
|
Verma-Gaur J, Traven A. Post-transcriptional gene regulation in the biology and virulence of Candida albicans. Cell Microbiol 2016; 18:800-6. [PMID: 26999710 PMCID: PMC5074327 DOI: 10.1111/cmi.12593] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2016] [Revised: 02/28/2016] [Accepted: 03/16/2016] [Indexed: 11/27/2022]
Abstract
In the human fungal pathogen Candida albicans, remodelling of gene expression drives host adaptation and virulence. Recent studies revealed that in addition to transcription, post‐transcriptional mRNA control plays important roles in virulence‐related pathways. Hyphal morphogenesis, biofilm formation, stress responses, antifungal drug susceptibility and virulence in animal models require post‐transcriptional regulators. This includes RNA binding proteins that control mRNA localization, decay and translation, as well as the cytoplasmic mRNA decay pathway. Comprehensive understanding of how modulation of gene expression networks drives C. albicans virulence will necessitate integration of our knowledge on transcriptional and post‐transcriptional mRNA control.
Collapse
Affiliation(s)
- Jiyoti Verma-Gaur
- Infection and Immunity Program and the Department of Biochemistry and Molecular Biology, Biomedicine Discovery Institute, Monash University, Clayton, VIC, Australia
| | - Ana Traven
- Infection and Immunity Program and the Department of Biochemistry and Molecular Biology, Biomedicine Discovery Institute, Monash University, Clayton, VIC, Australia
| |
Collapse
|
17
|
Wells ML, Hicks SN, Perera L, Blackshear PJ. Functional equivalence of an evolutionarily conserved RNA binding module. J Biol Chem 2015; 290:24413-23. [PMID: 26292216 DOI: 10.1074/jbc.m115.673012] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2015] [Indexed: 11/06/2022] Open
Abstract
Members of the tristetraprolin (TTP) family of proteins participate in the regulation of mRNA turnover after initially binding to AU-rich elements in target mRNAs. Related proteins from most groups of eukaryotes contain a conserved tandem zinc finger (TZF) domain consisting of two closely spaced, similar CCCH zinc fingers that form the primary RNA binding domain. There is considerable sequence variation within the TZF domains from different family members within a single organism and from different organisms, raising questions about sequence-specific effects on RNA binding and decay promotion. We hypothesized that TZF domains from evolutionarily distant species are functionally interchangeable. The single family member expressed in the fission yeast Schizosaccharomyces pombe, Zfs1, promotes the turnover of several dozen transcripts, some of which are involved in cell-cell interactions. Using knockin techniques, we replaced the TZF domain of S. pombe Zfs1 with the equivalent domains from human TTP and the single family member proteins expressed in the silkworm Bombyx mori, the pathogenic yeast Candida guilliermondii, and the plant Chromolaena odorata. We found that the TZF domains from these widely disparate species could completely substitute for the native S. pombe TZF domain, as determined by measurement of target transcript levels and the flocculation phenotype characteristic of Zfs1 deletion. Recombinant TZF domain peptides from several of these species bound to an AU-rich RNA oligonucleotide with comparably high affinity. We conclude that the TZF domains from TTP family members in these evolutionarily widely divergent species are functionally interchangeable in mRNA binding and decay.
Collapse
Affiliation(s)
| | | | - Lalith Perera
- Genome Integrity and Structural Biology Laboratory, NIEHS/National Institutes of Health, Research Triangle Park, North Carolina 27709 and
| | - Perry J Blackshear
- From the Signal Transduction Laboratory and Departments of Medicine and Biochemistry, Duke University, Medical Center, Durham, North Carolina 27710
| |
Collapse
|
18
|
Fox EP, Bui CK, Nett JE, Hartooni N, Mui MC, Andes DR, Nobile CJ, Johnson AD. An expanded regulatory network temporally controls Candida albicans biofilm formation. Mol Microbiol 2015; 96:1226-39. [PMID: 25784162 PMCID: PMC4464956 DOI: 10.1111/mmi.13002] [Citation(s) in RCA: 118] [Impact Index Per Article: 13.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/15/2015] [Indexed: 01/10/2023]
Abstract
Candida albicans biofilms are composed of highly adherent and densely arranged cells with properties distinct from those of free‐floating (planktonic) cells. These biofilms are a significant medical problem because they commonly form on implanted medical devices, are drug resistant and are difficult to remove. C. albicans biofilms are not static structures; rather they are dynamic and develop over time. Here we characterize gene expression in biofilms during their development, and by comparing them to multiple planktonic reference states, we identify patterns of gene expression relevant to biofilm formation. In particular, we document time‐dependent changes in genes involved in adhesion and metabolism, both of which are at the core of biofilm development. Additionally, we identify three new regulators of biofilm formation, Flo8, Gal4, and Rfx2, which play distinct roles during biofilm development over time. Flo8 is required for biofilm formation at all time points, and Gal4 and Rfx2 are needed for proper biofilm formation at intermediate time points.
Collapse
Affiliation(s)
- Emily P Fox
- Department of Microbiology and Immunology, University of California, San Francisco, CA, USA.,Tetrad Program, Department of Biochemistry and Biophysics, University of California, San Francisco, CA, USA
| | - Catherine K Bui
- School of Natural Sciences, University of California, Merced, CA, USA
| | - Jeniel E Nett
- Department of Medical Microbiology and Immunology, University of Wisconsin, Madison, WI, USA.,Department of Medicine, University of Wisconsin, Madison, WI, USA
| | - Nairi Hartooni
- Department of Microbiology and Immunology, University of California, San Francisco, CA, USA
| | - Michael C Mui
- Department of Microbiology and Immunology, University of California, San Francisco, CA, USA
| | - David R Andes
- Department of Medical Microbiology and Immunology, University of Wisconsin, Madison, WI, USA.,Department of Medicine, University of Wisconsin, Madison, WI, USA
| | - Clarissa J Nobile
- School of Natural Sciences, University of California, Merced, CA, USA
| | - Alexander D Johnson
- Department of Microbiology and Immunology, University of California, San Francisco, CA, USA
| |
Collapse
|