1
|
Lash E, Maufrais C, Janbon G, Robbins N, Herzel L, Cowen LE. The spliceosome impacts morphogenesis in the human fungal pathogen Candida albicans. mBio 2024; 15:e0153524. [PMID: 38980041 DOI: 10.1128/mbio.01535-24] [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: 05/23/2024] [Accepted: 05/31/2024] [Indexed: 07/10/2024] Open
Abstract
At human body temperature, the fungal pathogen Candida albicans can transition from yeast to filamentous morphologies in response to host-relevant cues. Additionally, elevated temperatures encountered during febrile episodes can independently induce C. albicans filamentation. However, the underlying genetic pathways governing this developmental transition in response to elevated temperatures remain largely unexplored. Here, we conducted a functional genomic screen to unravel the genetic mechanisms orchestrating C. albicans filamentation specifically in response to elevated temperature, implicating 45% of genes associated with the spliceosome or pre-mRNA splicing in this process. Employing RNA-Seq to elucidate the relationship between mRNA splicing and filamentation, we identified greater levels of intron retention in filaments compared to yeast, which correlated with reduced expression of the affected genes. Intriguingly, homozygous deletion of a gene encoding a spliceosome component important for filamentation (PRP19) caused even greater levels of intron retention compared with wild type and displayed globally dysregulated gene expression. This suggests that intron retention is a mechanism for fine-tuning gene expression during filamentation, with perturbations of the spliceosome exacerbating this process and blocking filamentation. Overall, this study unveils a novel biological process governing C. albicans filamentation, providing new insights into the complex regulation of this key virulence trait.IMPORTANCEFungal pathogens such as Candida albicans can cause serious infections with high mortality rates in immunocompromised individuals. When C. albicans is grown at temperatures encountered during human febrile episodes, yeast cells undergo a transition to filamentous cells, and this process is key to its virulence. Here, we expanded our understanding of how C. albicans undergoes filamentation in response to elevated temperature and identified many genes involved in mRNA splicing that positively regulate filamentation. Through transcriptome analyses, we found that intron retention is a mechanism for fine-tuning gene expression in filaments, and perturbation of the spliceosome exacerbates intron retention and alters gene expression substantially, causing a block in filamentation. This work adds to the growing body of knowledge on the role of introns in fungi and provides new insights into the cellular processes that regulate a key virulence trait in C. albicans.
Collapse
Affiliation(s)
- Emma Lash
- Department of Molecular Genetics, University of Toronto, Toronto, Ontario, Canada
| | - Corinne Maufrais
- Unité Biologie des ARN des Pathogènes Fongiques, Institut Pasteur, Université Paris Cité, Paris, France
- HUB Bioinformatique et Biostatistique, Institut Pasteur, Université Paris Cité, Paris, France
| | - Guilhem Janbon
- Unité Biologie des ARN des Pathogènes Fongiques, Institut Pasteur, Université Paris Cité, Paris, France
| | - Nicole Robbins
- Department of Molecular Genetics, University of Toronto, Toronto, Ontario, Canada
| | - Lydia Herzel
- Institute of Chemistry and Biochemistry, Freie Universität Berlin, Berlin, Germany
| | - Leah E Cowen
- Department of Molecular Genetics, University of Toronto, Toronto, Ontario, Canada
| |
Collapse
|
2
|
Wang Y, Seliger B. Identification of RNA-binding protein hnRNP C targeting the 3'UTR of the TAP-associated glycoprotein tapasin in melanoma. Oncoimmunology 2024; 13:2370928. [PMID: 38948930 PMCID: PMC11212565 DOI: 10.1080/2162402x.2024.2370928] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2024] [Accepted: 06/18/2024] [Indexed: 07/02/2024] Open
Abstract
Deregulation or loss of the human leukocyte antigen class I (HLA-I) molecules on tumor cells leading to inhibition of CD8+ T cell recognition is an important tumor immune escape strategy, which could be caused by a posttranscriptional control of molecules in the HLA-I pathway mediated by RNA-binding proteins (RBPs). So far, there exists only limited information about the interaction of RBPs with HLA-I-associated molecules, but own work demonstrated a binding of the heterogeneous ribonucleoprotein C (hnRNP C) to the 3' untranslated region (UTR) of the TAP-associated glycoprotein tapasin (tpn). In this study, in silico analysis of pan-cancer TCGA datasets revealed that hnRNP C is higher expressed in tumor specimens compared to corresponding normal tissues, which is negatively correlated to tpn expression, T cell infiltration and the overall survival of tumor patients. Functional analysis demonstrated an upregulation of tpn expression upon siRNA-mediated downregulation of hnRNP C, which is accompanied by an increased HLA-I surface expression. Thus, hnRNP C has been identified to target tpn and its inhibition could improve the HLA-I surface expression on melanoma cells suggesting its use as a possible biomarker for T-cell-based tumor immunotherapies.
Collapse
Affiliation(s)
- Yuan Wang
- Institute for Medical Immunology, Martin Luther University of Halle-Wittenberg, Halle (Saale), Germany
| | - Barbara Seliger
- Institute for Medical Immunology, Martin Luther University of Halle-Wittenberg, Halle (Saale), Germany
- Institute of Translational Immunology, Medical School “Theodor Fontane”, Brandenburg an der Havel, Germany
| |
Collapse
|
3
|
Firdous Z, Kalra S, Chattopadhyay R, Bari VK. Current insight into the role of mRNA decay pathways in fungal pathogenesis. Microbiol Res 2024; 283:127671. [PMID: 38479232 DOI: 10.1016/j.micres.2024.127671] [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: 12/18/2023] [Revised: 02/19/2024] [Accepted: 02/29/2024] [Indexed: 04/17/2024]
Abstract
Pathogenic fungal species can cause superficial and mucosal infections, to potentially fatal systemic or invasive infections in humans. These infections are more common in immunocompromised or critically ill patients and have a significant morbidity and fatality rate. Fungal pathogens utilize several strategies to adapt the host environment resulting in efficient and comprehensive alterations in their cellular metabolism. Fungal virulence is regulated by several factors and post-transcriptional regulation mechanisms involving mRNA molecules are one of them. Post-transcriptional controls have emerged as critical regulatory mechanisms involved in the pathogenesis of fungal species. The untranslated upstream and downstream regions of the mRNA, as well as RNA-binding proteins, regulate morphogenesis and virulence by controlling mRNA degradation and stability. The limited number of available therapeutic drugs, the emergence of multidrug resistance, and high death rates associated with systemic fungal illnesses pose a serious risk to human health. Therefore, new antifungal treatments that specifically target mRNA pathway components can decrease fungal pathogenicity and when combined increase the effectiveness of currently available antifungal drugs. This review summarizes the mRNA degradation pathways and their role in fungal pathogenesis.
Collapse
Affiliation(s)
- Zulikha Firdous
- Department of Biochemistry, School of Basic Sciences, Central University of Punjab, VPO-Ghudda, Bathinda 151401, India
| | - Sapna Kalra
- Department of Biochemistry, School of Basic Sciences, Central University of Punjab, VPO-Ghudda, Bathinda 151401, India
| | - Rituja Chattopadhyay
- Department of Biochemistry, School of Basic Sciences, Central University of Punjab, VPO-Ghudda, Bathinda 151401, India
| | - Vinay Kumar Bari
- Department of Biochemistry, School of Basic Sciences, Central University of Punjab, VPO-Ghudda, Bathinda 151401, India.
| |
Collapse
|
4
|
Shi W, Yang J, Chen D, Yin C, Zhang H, Xu X, Pan X, Wang R, Fei L, Li M, Qi L, Bhadauria V, Liu J, Peng YL. The rice blast fungus SR protein 1 regulates alternative splicing with unique mechanisms. PLoS Pathog 2022; 18:e1011036. [PMID: 36480554 PMCID: PMC9767378 DOI: 10.1371/journal.ppat.1011036] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2022] [Revised: 12/20/2022] [Accepted: 11/30/2022] [Indexed: 12/13/2022] Open
Abstract
Serine/arginine-rich (SR) proteins are well known as splicing factors in humans, model animals and plants. However, they are largely unknown in regulating pre-mRNA splicing of filamentous fungi. Here we report that the SR protein MoSrp1 enhances and suppresses alternative splicing in a model fungal plant pathogen Magnaporthe oryzae. Deletion of MoSRP1 caused multiple defects, including reduced virulence and thousands of aberrant alternative splicing events in mycelia, most of which were suppressed or enhanced intron splicing. A GUAG consensus bound by MoSrp1 was identified in more than 94% of the intron or/and proximate exons having the aberrant splicing. The dual functions of regulating alternative splicing of MoSrp1 were exemplified in enhancing and suppressing the consensus-mediated efficient splicing of the introns in MoATF1 and MoMTP1, respectively, which both were important for mycelial growth, conidiation, and virulence. Interestingly, MoSrp1 had a conserved sumoylation site that was essential to nuclear localization and enhancing GUAG binding. Further, we showed that MoSrp1 interacted with a splicing factor and two components of the exon-joining complex via its N-terminal RNA recognition domain, which was required to regulate mycelial growth, development and virulence. In contrast, the C-terminus was important only for virulence and stress responses but not for mycelial growth and development. In addition, only orthologues from Pezizomycotina species could completely rescue defects of the deletion mutants. This study reveals that the fungal conserved SR protein Srp1 regulates alternative splicing in a unique manner.
Collapse
Affiliation(s)
- Wei Shi
- State Key Laboratory of Agrobiotechnology, China Agricultural University, Beijing, China
- MARA Key Laboratory of Pest Monitoring and Green Management, Department of Plant Pathology, College of Plant Protection, China Agricultural University, Beijing, China
| | - Jun Yang
- MARA Key Laboratory of Pest Monitoring and Green Management, Department of Plant Pathology, College of Plant Protection, China Agricultural University, Beijing, China
- MARA Key Laboratory of Surveillance and Management for Plant Quarantine Pests, Department of Plant Biosecurity, College of Plant Protection, China Agricultural University, Beijing, China
| | - Deng Chen
- State Key Laboratory of Agrobiotechnology, China Agricultural University, Beijing, China
- MARA Key Laboratory of Pest Monitoring and Green Management, Department of Plant Pathology, College of Plant Protection, China Agricultural University, Beijing, China
| | - Changfa Yin
- State Key Laboratory of Agrobiotechnology, China Agricultural University, Beijing, China
- MARA Key Laboratory of Pest Monitoring and Green Management, Department of Plant Pathology, College of Plant Protection, China Agricultural University, Beijing, China
| | - Huixia Zhang
- MARA Key Laboratory of Pest Monitoring and Green Management, Department of Plant Pathology, College of Plant Protection, China Agricultural University, Beijing, China
- MARA Key Laboratory of Surveillance and Management for Plant Quarantine Pests, Department of Plant Biosecurity, College of Plant Protection, China Agricultural University, Beijing, China
| | - Xiaozhou Xu
- State Key Laboratory of Agrobiotechnology, China Agricultural University, Beijing, China
- MARA Key Laboratory of Pest Monitoring and Green Management, Department of Plant Pathology, College of Plant Protection, China Agricultural University, Beijing, China
| | - Xiao Pan
- MARA Key Laboratory of Pest Monitoring and Green Management, Department of Plant Pathology, College of Plant Protection, China Agricultural University, Beijing, China
- MARA Key Laboratory of Surveillance and Management for Plant Quarantine Pests, Department of Plant Biosecurity, College of Plant Protection, China Agricultural University, Beijing, China
| | - Ruijin Wang
- MARA Key Laboratory of Pest Monitoring and Green Management, Department of Plant Pathology, College of Plant Protection, China Agricultural University, Beijing, China
- MARA Key Laboratory of Surveillance and Management for Plant Quarantine Pests, Department of Plant Biosecurity, College of Plant Protection, China Agricultural University, Beijing, China
| | - Liwang Fei
- State Key Laboratory of Agrobiotechnology, China Agricultural University, Beijing, China
- MARA Key Laboratory of Pest Monitoring and Green Management, Department of Plant Pathology, College of Plant Protection, China Agricultural University, Beijing, China
| | - Mengfei Li
- State Key Laboratory of Agrobiotechnology, China Agricultural University, Beijing, China
- MARA Key Laboratory of Pest Monitoring and Green Management, Department of Plant Pathology, College of Plant Protection, China Agricultural University, Beijing, China
| | - Linlu Qi
- MARA Key Laboratory of Pest Monitoring and Green Management, Department of Plant Pathology, College of Plant Protection, China Agricultural University, Beijing, China
| | - Vijai Bhadauria
- MARA Key Laboratory of Pest Monitoring and Green Management, Department of Plant Pathology, College of Plant Protection, China Agricultural University, Beijing, China
| | - Junfeng Liu
- State Key Laboratory of Agrobiotechnology, China Agricultural University, Beijing, China
- MARA Key Laboratory of Pest Monitoring and Green Management, Department of Plant Pathology, College of Plant Protection, China Agricultural University, Beijing, China
| | - You-Liang Peng
- State Key Laboratory of Agrobiotechnology, China Agricultural University, Beijing, China
- MARA Key Laboratory of Pest Monitoring and Green Management, Department of Plant Pathology, College of Plant Protection, China Agricultural University, Beijing, China
- * E-mail:
| |
Collapse
|
5
|
Hall RA, Wallace EW. Post-transcriptional control of fungal cell wall synthesis. Cell Surf 2022; 8:100074. [PMID: 35097244 PMCID: PMC8783092 DOI: 10.1016/j.tcsw.2022.100074] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2021] [Revised: 01/10/2022] [Accepted: 01/10/2022] [Indexed: 12/21/2022] Open
Abstract
Pathogenic fungi hide from their hosts by camouflage, obscuring immunogenic cell wall components such as beta-glucan with innocuous coverings such as mannoproteins and alpha-glucan that are less readily recognised by the host. Attempts to understand how such processes are regulated have met with varying success. Typically studies focus on understanding the transcriptional response of fungi to either their reservoir environment or the host. However, such approaches do not fully address this research question, due to the layers of post-transcriptional and post-translational regulation that occur within a cell. Although in animals the impact of post-transcriptional and post-translational regulation has been well characterised, our knowledge of these processes in the fungal kingdom is more limited. Mutations in RNA-binding proteins, like Ssd1 and Candida albicans Slr1, affect cell wall composition and fungal virulence indicating that post-transcriptional regulation plays a key role in these processes. Here, we review the current state of knowledge of fungal post-transcriptional regulation, and link this to potential mechanisms of immune evasion by drawing on studies from model yeast and plant pathogenic fungi. We highlight several RNA-binding proteins that regulate cell wall synthesis and could be involved in local translation of cell wall components. Expanding our knowledge on post-transcriptional regulation in human fungal pathogens is essential to fully comprehend fungal virulence strategies and for the design of novel antifungal therapies.
Collapse
Affiliation(s)
- Rebecca A. Hall
- Kent Fungal Group, Division of Natural Sciences, School of Biosciences, University of Kent, Canterbury CT2 7NJ, United Kingdom
| | - Edward W.J. Wallace
- Institute for Cell Biology and SynthSys, School of Biological Sciences, University of Edinburgh, EH9 3FF, United Kingdom
| |
Collapse
|
6
|
Muzafar S, Sharma RD, Chauhan N, Prasad R. Intron distribution and emerging role of alternative splicing in fungi. FEMS Microbiol Lett 2021; 368:6414529. [PMID: 34718529 DOI: 10.1093/femsle/fnab135] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2021] [Accepted: 10/28/2021] [Indexed: 12/16/2022] Open
Abstract
Spliceosomal introns are noncoding sequences that are spliced from pre-mRNA. They are ubiquitous in eukaryotic genomes, although the average number of introns per gene varies considerably between different eukaryotic species. Fungi are diverse in terms of intron numbers ranging from 4% to 99% genes with introns. Alternative splicing is one of the most common modes of posttranscriptional regulation in eukaryotes, giving rise to multiple transcripts from a single pre-mRNA and is widespread in metazoans and drives extensive proteome diversity. Earlier, alternative splicing was considered to be rare in fungi, but recently, increasing numbers of studies have revealed that alternative splicing is also widespread in fungi and has been implicated in the regulation of fungal growth and development, protein localization and the improvement of survivability, likely underlying their unique capacity to adapt to changing environmental conditions. However, the role of alternative splicing in pathogenicity and development of drug resistance is only recently gaining attention. In this review, we describe the intronic landscape in fungi. We also present in detail the newly discovered functions of alternative splicing in various cellular processes and outline areas particularly in pathogenesis and clinical drug resistance for future studies that could lead to the development of much needed new therapeutics.
Collapse
Affiliation(s)
- Suraya Muzafar
- Amity Institute of Integrative Sciences and Health, Amity University Gurgaon, Gurgaon 122413, Haryana, India
| | - Ravi Datta Sharma
- Amity Institute of Integrative Sciences and Health, Amity University Gurgaon, Gurgaon 122413, Haryana, India
| | - Neeraj Chauhan
- Public Health Research Institute, New Jersey Medical School, Rutgers, The State University of New Jersey, Newark, NJ 07103, USA
| | - Rajendra Prasad
- Amity Institute of Integrative Sciences and Health, Amity University Gurgaon, Gurgaon 122413, Haryana, India
| |
Collapse
|
7
|
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
|
8
|
Gargouch N, Elleuch F, Karkouch I, Tabbene O, Pichon C, Gardarin C, Rihouey C, Picton L, Abdelkafi S, Fendri I, Laroche C. Potential of Exopolysaccharide from Porphyridium marinum to Contend with Bacterial Proliferation, Biofilm Formation, and Breast Cancer. Mar Drugs 2021; 19:66. [PMID: 33513982 PMCID: PMC7911520 DOI: 10.3390/md19020066] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2020] [Revised: 01/21/2021] [Accepted: 01/22/2021] [Indexed: 12/18/2022] Open
Abstract
Exopolysaccharide (EPS) from marine microalgae are promising sources of a new generation of drugs. However, lot of them remain to be discovered and tested. In this study, EPS produced by Porphyridium marinum and its oligomers prepared by High Pressure Homogenizer have been tested for different biological activities, i.e., antibacterial, anti-fungal and antibiofilm activities on Candida albicans, as well as for their effects on the viability of murine breast cancer cells. Results have shown that all EPS samples present some biological activity. For antibacterial and antibiofilm activities, the native EPS exhibited a better efficiency with Minimum Inhibitory Concentration (MIC) from 62.5 µg/mL to 1000 µg/mL depending on the bacterial strain. For Candida albicans, the biofilm formation was reduced by about 90% by using only a 31.3 µg/mL concentration. Concerning breast cancer cells, lower molar masses fractions appeared to be more efficient, with a reduction of viability of up to 55%. Finally, analyses of polymers composition and viscosity measurements were conducted on all samples, in order to propose hypotheses involving the activities caused by the intrinsic properties of polymers.
Collapse
Affiliation(s)
- Nesrine Gargouch
- Institut Pascal, CNRS, SIGMA Clermont, Université Clermont Auvergne, F-63000 Clermont-Ferrand, France; (N.G.); (C.G.)
- Laboratoire de Biotechnologie Végétale Appliquée à l’Amélioration des Cultures, Faculty of Sciences of Sfax, University of Sfax, Sfax 3000, Tunisia;
| | - Fatma Elleuch
- Centre de Biophysique Moléculaire, CNRS-UPR 4301, 45071 Orléans, France; (F.E.); (C.P.)
- Unité de Biotechnologie des Algues, Biological Engineering Department, National School of Engineers of Sfax, University of Sfax, Sfax 3038, Tunisia;
| | - Ines Karkouch
- Laboratory of Bioactive Substances, Biotechnology Center of Borj-Cedria (CBBC), BP-901, Hammam-Lif 2050, Tunisia; (I.K.); (O.T.)
| | - Olfa Tabbene
- Laboratory of Bioactive Substances, Biotechnology Center of Borj-Cedria (CBBC), BP-901, Hammam-Lif 2050, Tunisia; (I.K.); (O.T.)
| | - Chantal Pichon
- Centre de Biophysique Moléculaire, CNRS-UPR 4301, 45071 Orléans, France; (F.E.); (C.P.)
| | - Christine Gardarin
- Institut Pascal, CNRS, SIGMA Clermont, Université Clermont Auvergne, F-63000 Clermont-Ferrand, France; (N.G.); (C.G.)
| | - Christophe Rihouey
- Normandie University, UNIROUEN, INSA Rouen, CNRS, PBS, 76000 Rouen, France; (C.R.); (L.P.)
| | - Luc Picton
- Normandie University, UNIROUEN, INSA Rouen, CNRS, PBS, 76000 Rouen, France; (C.R.); (L.P.)
| | - Slim Abdelkafi
- Unité de Biotechnologie des Algues, Biological Engineering Department, National School of Engineers of Sfax, University of Sfax, Sfax 3038, Tunisia;
| | - Imen Fendri
- Laboratoire de Biotechnologie Végétale Appliquée à l’Amélioration des Cultures, Faculty of Sciences of Sfax, University of Sfax, Sfax 3000, Tunisia;
| | - Céline Laroche
- Institut Pascal, CNRS, SIGMA Clermont, Université Clermont Auvergne, F-63000 Clermont-Ferrand, France; (N.G.); (C.G.)
| |
Collapse
|
9
|
Identification of Genomewide Alternative Splicing Events in Sequential, Isogenic Clinical Isolates of Candida albicans Reveals a Novel Mechanism of Drug Resistance and Tolerance to Cellular Stresses. mSphere 2020; 5:5/4/e00608-20. [PMID: 32817456 PMCID: PMC7426172 DOI: 10.1128/msphere.00608-20] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The emergence of resistance in Candida albicans, an opportunistic pathogen, against the commonly used antifungals is becoming a major obstacle in its treatment. The necessity to identify new drug targets demands fundamental insights into the mechanisms used by this organism to develop drug resistance. C. albicans has introns in 4 to 6% of its genes, the functions of which remain largely unknown. Using the RNA-sequencing data from isogenic pairs of azole-sensitive and -resistant isolates of C. albicans, here, we show how C. albicans uses modulations in mRNA splicing to overcome antifungal drug stress. Alternative splicing (AS)—a process by which a single gene gives rise to different protein isoforms in eukaryotes—has been implicated in many basic cellular processes, but little is known about its role in drug resistance and fungal pathogenesis. The most common human fungal pathogen, Candida albicans, has introns in 4 to 6% of its genes, the functions of which remain largely unknown. Here, we report AS regulating drug resistance in C. albicans. Comparative RNA-sequencing of two different sets of sequential, isogenic azole-sensitive and -resistant isolates of C. albicans revealed differential expression of splice isoforms of 14 genes. One of these was the superoxide dismutase gene SOD3, which contains a single intron. The sod3Δ/Δ mutant was susceptible to the antifungals amphotericin B (AMB) and menadione (MND). While AMB susceptibility was rescued by overexpression of both the spliced and unspliced SOD3 isoforms, only the spliced isoform could overcome MND susceptibility, demonstrating the functional relevance of this splicing in developing drug resistance. Furthermore, unlike AMB, MND inhibits SOD3 splicing and acts as a splicing inhibitor. Consistent with these observations, MND exposure resulted in increased levels of unspliced SOD3 isoform that are unable to scavenge reactive oxygen species (ROS), resulting in increased drug susceptibility. Collectively, these observations suggest that AS is a novel mechanism for stress adaptation and overcoming drug susceptibility in C. albicans. IMPORTANCE The emergence of resistance in Candida albicans, an opportunistic pathogen, against the commonly used antifungals is becoming a major obstacle in its treatment. The necessity to identify new drug targets demands fundamental insights into the mechanisms used by this organism to develop drug resistance. C. albicans has introns in 4 to 6% of its genes, the functions of which remain largely unknown. Using the RNA-sequencing data from isogenic pairs of azole-sensitive and -resistant isolates of C. albicans, here, we show how C. albicans uses modulations in mRNA splicing to overcome antifungal drug stress.
Collapse
|
10
|
Ahamefule CS, Qin Q, Odiba AS, Li S, Moneke AN, Ogbonna JC, Jin C, Wang B, Fang W. Caenorhabditis elegans-Based Aspergillus fumigatus Infection Model for Evaluating Pathogenicity and Drug Efficacy. Front Cell Infect Microbiol 2020; 10:320. [PMID: 32670897 PMCID: PMC7332887 DOI: 10.3389/fcimb.2020.00320] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2020] [Accepted: 05/26/2020] [Indexed: 11/13/2022] Open
Abstract
Aspergillus fumigatus is the most reported causative pathogen associated with the increasing global incidences of aspergilloses, with the health of immunocompromised individuals mostly at risk. Monitoring the pathogenicity of A. fumigatus strains to identify virulence factors and evaluating the efficacy of potent active agents against this fungus in animal models are indispensable in current research effort. Caenorhabditis elegans has been successfully utilized as an infection model for bacterial and dimorphic fungal pathogens because of the advantages of being time-efficient, and less costly. However, application of this model to the filamentous fungus A. fumigatus is less investigated. In this study, we developed and optimized a stable and reliable C. elegans model for A. fumigatus infection, and demonstrated the infection process with a fluorescent strain. Virulence results of several mutant strains in our nematode model demonstrated high consistency with the already reported pathogenicity pattern in other models. Furthermore, this C. elegans-A. fumigatus infection model was optimized for evaluating the efficacy of current antifungal drugs. Interestingly, the azole drugs in nematode model prevented conidial germination to a higher extent than amphotericin B. Overall, our established C. elegans infection model for A. fumigatus has potential applications in pathogenicity evaluation, antifungal agents screening, drug efficacy evaluation as well as host-pathogen interaction studies.
Collapse
Affiliation(s)
- Chukwuemeka Samson Ahamefule
- National Engineering Research Center for Non-food Biorefinery, Guangxi Academy of Sciences, Nanning, China
- College of Life Science and Technology, Guangxi University, Nanning, China
- Department of Microbiology, University of Nigeria, Nsukka, Nigeria
| | - Qijian Qin
- National Engineering Research Center for Non-food Biorefinery, Guangxi Academy of Sciences, Nanning, China
| | - Arome Solomon Odiba
- National Engineering Research Center for Non-food Biorefinery, Guangxi Academy of Sciences, Nanning, China
- College of Life Science and Technology, Guangxi University, Nanning, China
| | - Siqiao Li
- State Key Laboratory of Non-food Biomass and Enzyme Technology, Guangxi Academy of Sciences, Nanning, China
| | - Anene N. Moneke
- Department of Microbiology, University of Nigeria, Nsukka, Nigeria
| | - James C. Ogbonna
- Department of Microbiology, University of Nigeria, Nsukka, Nigeria
| | - Cheng Jin
- National Engineering Research Center for Non-food Biorefinery, Guangxi Academy of Sciences, Nanning, China
- College of Life Science and Technology, Guangxi University, Nanning, China
| | - Bin Wang
- National Engineering Research Center for Non-food Biorefinery, Guangxi Academy of Sciences, Nanning, China
- State Key Laboratory of Non-food Biomass and Enzyme Technology, Guangxi Academy of Sciences, Nanning, China
| | - Wenxia Fang
- National Engineering Research Center for Non-food Biorefinery, Guangxi Academy of Sciences, Nanning, China
- State Key Laboratory of Non-food Biomass and Enzyme Technology, Guangxi Academy of Sciences, Nanning, China
| |
Collapse
|
11
|
Shahbaaz M, Potemkin V, Bisetty K, Hassan MI, Hussien MA. Classification and functional analyses of putative virulence factors of Mycobacterium tuberculosis: A combined sequence and structure based study. Comput Biol Chem 2020; 87:107270. [PMID: 32438116 DOI: 10.1016/j.compbiolchem.2020.107270] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2019] [Revised: 04/16/2020] [Accepted: 04/26/2020] [Indexed: 11/17/2022]
Abstract
The emergence of the drug-resistant mechanisms in Mycobacterium tuberculosis poses the biggest challenges to the current therapeutic measures, which necessitates the identification of new drug targets. The Hypothetical Proteins (HPs), a class of functionally uncharacterized proteins, may provide a new class of undiscovered therapeutic targets. The genome of M. tuberculosis contains 1000 HPs with their sequences were analyzed using a variety of bioinformatics tools and the functional annotations were performed. The functions of 662 HPs were successfully predicted and further classified 483 HPs as enzymes, 141 HPs were predicted to be involved in the diverse cellular mechanisms and 38 HPs may function as transporters and carriers proteins. Furthermore, 28 HPs were predicted to be virulent in nature. Amongst them, the HP P95201, HP P9WM79, HP I6WZ30, HP I6 × 9T8, HP P9WKP3, and HP P9WK89 showed the highest virulence scores. Therefore, these proteins were subjected to extensive structure analyses and dynamics of their conformations were investigated using the principles of molecular dynamics simulations, each for a 150 ns time scale. This study provides a deeper understanding of the undiscovered drug targets and the generated outputs will facilitate the process of drug design and discovery against the infection of M. tuberculosis.
Collapse
Affiliation(s)
- Mohd Shahbaaz
- South African Medical Research Council Bioinformatics Unit, South African National Bioinformatics Institute (SANBI), University of the Western Cape, Private Bag X17, Bellville 7535, Cape Town, South Africa; Laboratory of Computational Modeling of Drugs, South Ural State University, 76 Lenin prospekt, 454080 Chelyabinsk, Russia
| | - Vladimir Potemkin
- Laboratory of Computational Modeling of Drugs, South Ural State University, 76 Lenin prospekt, 454080 Chelyabinsk, Russia
| | - Krishna Bisetty
- Department of Chemistry, Durban University of Technology, Durban, 4000, South Africa
| | - Md Imtaiyaz Hassan
- Center for Interdisciplinary Research in Basic Sciences, Jamia Millia Islamia, Jamia Nagar, New Delhi, 110025, India
| | - Mostafa A Hussien
- Department of Chemistry, Faculty of Science, King Abdulaziz University, P.O. Box 80203 Jeddah 21589, Saudi Arabia; Department of Chemistry, Faculty of Science, Port Said University, Port Said, 42521, Egypt
| |
Collapse
|
12
|
Sen T, Verma NK. Functional Annotation and Curation of Hypothetical Proteins Present in A Newly Emerged Serotype 1c of Shigella flexneri: Emphasis on Selecting Targets for Virulence and Vaccine Design Studies. Genes (Basel) 2020; 11:genes11030340. [PMID: 32210046 PMCID: PMC7141135 DOI: 10.3390/genes11030340] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2020] [Revised: 03/18/2020] [Accepted: 03/19/2020] [Indexed: 01/28/2023] Open
Abstract
Shigella flexneri is the principal cause of bacillary dysentery, contributing significantly to the global burden of diarrheal disease. The appearance and increase in the multi-drug resistance among Shigella strains, necessitates further genetic studies and development of improved/new drugs against the pathogen. The presence of an abundance of hypothetical proteins in the genome and how little is known about them, make them interesting genetic targets. The present study aims to carry out characterization of the hypothetical proteins present in the genome of a newly emerged serotype of S. flexneri (strain Y394), toward their novel regulatory functions using various bioinformatics databases/tools. Analysis of the genome sequence rendered 4170 proteins, out of which 721 proteins were annotated as hypothetical proteins (HPs) with no known function. The amino acid sequences of these HPs were evaluated using a combination of latest bioinformatics tools based on homology search against functionally identified proteins. Functional domains were considered as the basis to infer the biological functions of HPs in this case and the annotation helped in assigning various classes to the proteins such as signal transducers, lipoproteins, enzymes, membrane proteins, transporters, virulence, and binding proteins. This study contributes to a better understanding of growth, survival, and disease mechanism at molecular level and provides potential new targets for designing drugs against Shigella infection.
Collapse
|
13
|
The SR-protein FgSrp2 regulates vegetative growth, sexual reproduction and pre-mRNA processing by interacting with FgSrp1 in Fusarium graminearum. Curr Genet 2020; 66:607-619. [PMID: 32040734 DOI: 10.1007/s00294-020-01054-2] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2019] [Revised: 12/22/2019] [Accepted: 01/08/2020] [Indexed: 12/21/2022]
Abstract
Serine/arginine (SR) proteins play significant roles in pre-mRNA splicing in eukaryotes. To investigate how gene expression influences fungal development and pathogenicity in Fusarium graminearum, a causal agent of Fusarium head blight (FHB) of wheat and barley, our previous study identified a SR protein FgSrp1 in F. graminearum, and showed that it is important for conidiation, plant infection and pre-mRNA processing. In this study, we identified another SR protein FgSrp2 in F. graminearum, which is orthologous to Schizosaccharomyces pombe Srp2. Our data showed that, whereas yeast Srp2 is essential for growth, deletion of FgSRP2 resulted in only slight defects in vegetative growth and perithecia melanization. FgSrp2 localized to the nucleus and both its N- and C-terminal regions were important for the localization to the nucleus. FgSrp2 interacted with FgSrp1 to form a complex in vivo. Double deletion of FgSRP1 and FgSRP2 revealed that they had overlapping functions in vegetative growth and sexual reproduction. RNA-seq analysis revealed that, although deletion of FgSRP2 alone had minimal effects, deletion of both FgSRP1 and FgSRP2 caused significant changes in gene transcription and RNA splicing. Overall, our results indicated that FgSrp2 regulates vegetative growth, sexual reproduction and pre-mRNA processing by interacting with FgSrp1.
Collapse
|
14
|
Candida albicans rvs161Δ and rvs167Δ Endocytosis Mutants Are Defective in Invasion into the Oral Cavity. mBio 2019; 10:mBio.02503-19. [PMID: 31719181 PMCID: PMC6851284 DOI: 10.1128/mbio.02503-19] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
Oropharyngeal candidiasis (OPC) is a common fungal infection that is associated with severe morbidity. Another concern is that patients at risk for developing OPC often take long courses of antifungal drugs, which can lead to the emergence of drug-resistant C. albicans strains. We therefore identified nine mutants with defects in undergoing invasive hyphal growth in the oral cavity, increasing the number of genes known to be involved in OPC by more than 30%. The two strongest mutants, rvs161Δ and rvs167Δ, have defects in endocytosis. The rvsΔ mutants appear to have a specific defect in initiating invasive growth, as preinducing the cells to form hyphae prior to infection restored their ability to cause OPC. These results indicate that blocking endocytosis could have therapeutic value in preventing the initiation of OPC without leading to development of resistance against drugs currently used to treat fungal infections. Invasive growth in tissues by the human fungal pathogen Candida albicans is promoted by a switch from budding to hyphal morphogenesis that is stimulated by multiple environmental factors that can vary at different sites of infection. To identify genes that promote invasive growth in the oral cavity to cause oropharyngeal candidiasis (OPC), we first identified C. albicans mutants that failed to invade agar medium. Analysis of nine severely defective mutants in a mouse model of OPC revealed that the strongest defects were seen for the rvs161Δ and rvs167Δ mutants, which lack amphiphysin proteins needed for endocytosis. The rvsΔ mutants initially adhered to the tongue but failed to invade efficiently and were lost from the oral cavity. Previous studies indicated that rvsΔ mutants formed filamentous hyphae in the kidney albeit with morphological abnormalities, suggesting that the rvsΔ mutants were influenced by factors that vary at different sites of infection. Consistent with this, increasing concentrations of CO2, an inducer of hyphal growth that is more abundant in internal organs than air, partially rescued the invasive-growth defects of the rvsΔ mutants in vitro. Interestingly, preinduction of the rvsΔ mutants to form hyphae prior to introduction into the oral cavity restored their ability to cause OPC, identifying a key role for endocytosis in initiating invasive hyphal growth. These results highlight the influence of distinct environmental factors in promoting invasive hyphal growth in the oral cavity and indicate that blocking endocytosis could have therapeutic value in preventing the initiation of OPC.
Collapse
|
15
|
do Amaral CC, Fernandes GF, Rodrigues AM, Burger E, de Camargo ZP. Proteomic analysis of Paracoccidioides brasiliensis complex isolates: Correlation of the levels of differentially expressed proteins with in vivo virulence. PLoS One 2019; 14:e0218013. [PMID: 31265468 PMCID: PMC6605636 DOI: 10.1371/journal.pone.0218013] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2018] [Accepted: 05/23/2019] [Indexed: 01/02/2023] Open
Abstract
BACKGROUND Paracoccidioidomycosis (PCM) is a systemic mycosis commonly found in Latin America that is caused by distinct species of Paracoccidioides genus: Paracoccidioides brasiliensis complex (S1, PS2, PS3 and PS4) and Paracoccidioides lutzii. Its pathobiology has been recently explored by different approaches to clarify the mechanisms of host-pathogen interactions underpinning PCM. The diversity of clinical forms of this disease has been attributed to both host- and fungus-related factors. METHODOLOGY/PRINCIPAL FINDINGS For better understanding of the molecular underpinnings of host-fungus interactions, we evaluated in vivo virulence of nine Paracoccidioides brasiliensis complex isolates and correlated it to protein expression profiles obtained by two-dimensional gel electrophoresis. Based on the recovery of viable fungi from mouse organs, the isolates were classified as those having low, moderate, or high virulence. Highly virulent isolates overexpressed proteins related to adhesion process and stress response, probably indicating important roles of those fungal proteins in regulating the colonization capacity, survival, and ability to escape host immune system reaction. Moreover, highly virulent isolates exhibited enhanced expression of glycolytic pathway enzymes concomitantly with repressed expression of succinyl-CoA ligase beta chain, a protein related to the tricarboxylic acid cycle. CONCLUSIONS/SIGNIFICANCE Our findings may point to the mechanisms used by highly virulent P. brasiliensis isolates to withstand host immune reactions and to adapt to transient iron availability as strategies to survive and overcome stress conditions inside the host.
Collapse
Affiliation(s)
- Cristiane Candida do Amaral
- Department of Medicine, Discipline of Infectious Diseases, Federal University of São Paulo (UNIFESP), São Paulo, Brazil
| | - Geisa Ferreira Fernandes
- Department of Microbiology, Immunology and Parasitology, Discipline of Cellular Biology, Federal University of São Paulo (UNIFESP), São Paulo, Brazil
| | - Anderson Messias Rodrigues
- Department of Microbiology, Immunology and Parasitology, Discipline of Cellular Biology, Federal University of São Paulo (UNIFESP), São Paulo, Brazil
| | - Eva Burger
- Department of Microbiology and Immunology, Federal University of Alfenas (UNIFAL), Alfenas, Brazil
| | - Zoilo Pires de Camargo
- Department of Microbiology, Immunology and Parasitology, Discipline of Cellular Biology, Federal University of São Paulo (UNIFESP), São Paulo, Brazil
- * E-mail:
| |
Collapse
|
16
|
Liu L, Dalal CK, Heineike BM, Abate AR. High throughput gene expression profiling of yeast colonies with microgel-culture Drop-seq. LAB ON A CHIP 2019; 19:1838-1849. [PMID: 31020292 PMCID: PMC7909483 DOI: 10.1039/c9lc00084d] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/07/2023]
Abstract
Yeast can be engineered into "living foundries" for non-natural chemical production by reprogramming them via a "design-build-test" cycle. While methods for "design" and "build" are relatively scalable and efficient, "test" remains a bottleneck, limiting the effectiveness of the procedure. Here we describe isogenic colony sequencing (ICO-seq), a massively-parallel strategy to assess the gene expression, and thus engineered pathway efficacy, of large numbers of genetically distinct yeast colonies. We use the approach to characterize opaque-white switching in 658 C. albicans colonies. By profiling the transcriptomes of 1642 engineered S. cerevisiae strains, we assess gene expression heterogeneity in a protein mutagenesis library. Our approach will accelerate synthetic biology by allowing facile and cost-effective transcriptional profiling of large numbers of genetically distinct yeast strains.
Collapse
Affiliation(s)
- Leqian Liu
- Bioengineering and Therapeutic Sciences, University of California, San Francisco, San Francisco, CA 94158, USA.
| | | | | | | |
Collapse
|
17
|
Swidergall M, Solis NV, Lionakis MS, Filler SG. EphA2 is an epithelial cell pattern recognition receptor for fungal β-glucans. Nat Microbiol 2018; 3:53-61. [PMID: 29133884 PMCID: PMC5736406 DOI: 10.1038/s41564-017-0059-5] [Citation(s) in RCA: 111] [Impact Index Per Article: 18.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2017] [Accepted: 10/11/2017] [Indexed: 12/31/2022]
Abstract
Oral epithelial cells discriminate between pathogenic and non-pathogenic stimuli, and only induce an inflammatory response when they are exposed to high levels of a potentially harmful microorganism. The pattern recognition receptors (PRRs) in epithelial cells that mediate this differential response are poorly understood. Here, we demonstrate that the ephrin type-A receptor 2 (EphA2) is an oral epithelial cell PRR that binds to exposed β-glucans on the surface of the fungal pathogen Candida albicans. Binding of C. albicans to EphA2 on oral epithelial cells activates signal transducer and activator of transcription 3 and mitogen-activated protein kinase signalling in an inoculum-dependent manner, and is required for induction of a proinflammatory and antifungal response. EphA2 -/- mice have impaired inflammatory responses and reduced interleukin-17 signalling during oropharyngeal candidiasis, resulting in more severe disease. Our study reveals that EphA2 functions as a PRR for β-glucans that senses epithelial cell fungal burden and is required for the maximal mucosal inflammatory response to C. albicans.
Collapse
MESH Headings
- Animals
- Candida albicans/growth & development
- Candida albicans/metabolism
- Candidiasis, Oral/metabolism
- Candidiasis, Oral/pathology
- Cell Line
- Cytokines/biosynthesis
- Disease Models, Animal
- Endocytosis
- Epithelial Cells/cytology
- Epithelial Cells/metabolism
- Epithelial Cells/microbiology
- ErbB Receptors/antagonists & inhibitors
- ErbB Receptors/metabolism
- Inflammation Mediators/analysis
- Male
- Mice
- Mice, Inbred C57BL
- Mouth Mucosa/cytology
- Mouth Mucosa/metabolism
- Mouth Mucosa/microbiology
- Phosphorylation
- Receptor, EphA2/antagonists & inhibitors
- Receptor, EphA2/deficiency
- Receptor, EphA2/metabolism
- Receptors, Pattern Recognition/antagonists & inhibitors
- Receptors, Pattern Recognition/deficiency
- Receptors, Pattern Recognition/metabolism
- STAT3 Transcription Factor/metabolism
- Signal Transduction
- beta-Glucans/metabolism
Collapse
Affiliation(s)
- Marc Swidergall
- Division of Infectious Diseases, Los Angeles Biomedical Research Institute at Harbor-UCLA Medical Center, Torrance, CA, USA
| | - Norma V Solis
- Division of Infectious Diseases, Los Angeles Biomedical Research Institute at Harbor-UCLA Medical Center, Torrance, CA, USA
| | - Michail S Lionakis
- National Institute of Allergy and Infectious Diseases, National Institutes of Health, Fungal Pathogenesis Unit, Laboratory of Clinical Infectious Diseases, Bethesda, MD, USA
| | - Scott G Filler
- Division of Infectious Diseases, Los Angeles Biomedical Research Institute at Harbor-UCLA Medical Center, Torrance, CA, USA.
- David Geffen School of Medicine at UCLA, Los Angeles, CA, USA.
| |
Collapse
|
18
|
Sui X, Yan L, Jiang YY. The vaccines and antibodies associated with Als3p for treatment of Candida albicans infections. Vaccine 2017; 35:5786-5793. [DOI: 10.1016/j.vaccine.2017.08.082] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2017] [Revised: 08/14/2017] [Accepted: 08/29/2017] [Indexed: 12/20/2022]
|
19
|
Zhang Y, Gao X, Sun M, Liu H, Xu JR. The FgSRP1 SR-protein gene is important for plant infection and pre-mRNA processing in Fusarium graminearum. Environ Microbiol 2017; 19:4065-4079. [PMID: 28654215 DOI: 10.1111/1462-2920.13844] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2017] [Accepted: 06/21/2017] [Indexed: 12/15/2022]
Abstract
The versatile functions of SR (serine/arginine-rich) proteins in pre-mRNA splicing and processing are modulated by reversible phosphorylation. Previous studies showed that FgPrp4, the only protein kinase among spliceosome components, is important for intron splicing and the FgSrp1 SR protein is phosphorylated at five conserved sites in Fusarium graminearum. In this study, we showed that the Fgsrp1 deletion mutant rarely produced conidia and caused only limited symptoms on wheat heads and corn silks. Deletion of FgSRP1 also reduced ascospore ejection and deoxynivalenol (DON) production. Interestingly, FgSRP1 had two transcript isoforms due to alternative splicing and both of them were required for its normal functions in growth and DON biosynthesis. FgSrp1 localized to the nucleus and interacted with FgPrp4 in vivo. Deletion of all four conserved phosphorylation sites but not individual ones affected the FgSRP1 function, suggesting their overlapping functions. RNA-seq analysis showed that the expression of over thousands of genes and splicing efficiency in over 140 introns were affected. Taken together, FgSRP1 is important for conidiation, and pathogenesis and alternative splicing is important for its normal functions. The FgSrp1 SR protein is likely important for pre-mRNA processing or splicing of various genes in different developmental and infection processes.
Collapse
Affiliation(s)
- Yimei Zhang
- State Key Laboratory of Crop Stress Biology for Arid Areas and Purdue-NWAFU Joint Research Center, College of Plant Protection, Northwest A&F University, Yangling, Shaanxi 712100, China
| | - Xuli Gao
- State Key Laboratory of Crop Stress Biology for Arid Areas and Purdue-NWAFU Joint Research Center, College of Plant Protection, Northwest A&F University, Yangling, Shaanxi 712100, China
| | - Manli Sun
- State Key Laboratory of Crop Stress Biology for Arid Areas and Purdue-NWAFU Joint Research Center, College of Plant Protection, Northwest A&F University, Yangling, Shaanxi 712100, China
| | - Huiquan Liu
- State Key Laboratory of Crop Stress Biology for Arid Areas and Purdue-NWAFU Joint Research Center, College of Plant Protection, Northwest A&F University, Yangling, Shaanxi 712100, China
| | - Jin-Rong Xu
- State Key Laboratory of Crop Stress Biology for Arid Areas and Purdue-NWAFU Joint Research Center, College of Plant Protection, Northwest A&F University, Yangling, Shaanxi 712100, China.,Department of Botany and Plant Pathology, Purdue University, West Lafayette, IN 47907, USA
| |
Collapse
|
20
|
Messenger RNA transport in the opportunistic fungal pathogen Candida albicans. Curr Genet 2017; 63:989-995. [PMID: 28512683 DOI: 10.1007/s00294-017-0707-6] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2017] [Revised: 05/09/2017] [Accepted: 05/10/2017] [Indexed: 01/12/2023]
Abstract
Candida albicans, a common commensal fungus, can cause disease in immunocompromised hosts ranging from mild mucosal infections to severe bloodstream infections with high mortality rates. The ability of C. albicans cells to switch between a budding yeast form and an elongated hyphal form is linked to pathogenicity in animal models. Hyphal-specific proteins such as cell-surface adhesins and secreted hydrolases facilitate tissue invasion and host cell damage, but the specific mechanisms leading to asymmetric protein localization in hyphae remain poorly understood. In many eukaryotes, directional cytoplasmic transport of messenger RNAs that encode asymmetrically localized proteins allows efficient local translation at the site of protein function. Over the past two decades, detailed mechanisms for polarized mRNA transport have been elucidated in the budding yeast Saccharomyces cerevisiae and the filamentous fungus Ustilago maydis. This review highlights recent studies of RNA-binding proteins in C. albicans that have revealed intriguing similarities to and differences from known fungal mRNA transport systems. I also discuss outstanding questions that will need to be answered to reach an in-depth understanding of C. albicans mRNA transport mechanisms and the roles of asymmetric mRNA localization in polarized growth, hyphal function, and virulence of this opportunistic pathogen.
Collapse
|
21
|
Ariyachet C, Beißel C, Li X, Lorrey S, Mackenzie O, Martin PM, O'Brien K, Pholcharee T, Sim S, Krebber H, McBride AE. Post-translational modification directs nuclear and hyphal tip localization of Candida albicans mRNA-binding protein Slr1. Mol Microbiol 2017; 104:499-519. [PMID: 28187496 PMCID: PMC5405739 DOI: 10.1111/mmi.13643] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/06/2017] [Indexed: 12/21/2022]
Abstract
The morphological transition of the opportunistic fungal pathogen Candida albicans from budding to hyphal growth has been implicated in its ability to cause disease in animal models. Absence of SR‐like RNA‐binding protein Slr1 slows hyphal formation and decreases virulence in a systemic candidiasis model, suggesting a role for post‐transcriptional regulation in these processes. SR (serine–arginine)‐rich proteins influence multiple steps in mRNA metabolism and their localization and function are frequently controlled by modification. We now demonstrate that Slr1 binds to polyadenylated RNA and that its intracellular localization is modulated by phosphorylation and methylation. Wildtype Slr1‐GFP is predominantly nuclear, but also co‐fractionates with translating ribosomes. The non‐phosphorylatable slr1‐6SA‐GFP protein, in which six serines in SR/RS clusters are substituted with alanines, primarily localizes to the cytoplasm in budding cells. Intriguingly, hyphal cells display a slr1‐6SA‐GFP focus at the tip near the Spitzenkörper, a vesicular structure involved in molecular trafficking to the tip. The presence of slr1‐6SA‐GFP hyphal tip foci is reduced in the absence of the mRNA‐transport protein She3, suggesting that unphosphorylated Slr1 associates with mRNA–protein complexes transported to the tip. The impact of SLR1 deletion on hyphal formation and function thus may be partially due to a role in hyphal mRNA transport.
Collapse
Affiliation(s)
| | - Christian Beißel
- Abteilung für Molekulare Genetik, Institut für Mikrobiologie und Genetik, Göttinger Zentrum für Molekulare Biowissenschaften, Georg-August Universität Göttingen, Göttingen, Germany
| | - Xiang Li
- Biology Department, Bowdoin College, Brunswick, ME, 04011, USA
| | - Selena Lorrey
- Biology Department, Bowdoin College, Brunswick, ME, 04011, USA
| | | | | | | | | | - Sue Sim
- Biology Department, Bowdoin College, Brunswick, ME, 04011, USA
| | - Heike Krebber
- Abteilung für Molekulare Genetik, Institut für Mikrobiologie und Genetik, Göttinger Zentrum für Molekulare Biowissenschaften, Georg-August Universität Göttingen, Göttingen, Germany
| | - Anne E McBride
- Biology Department, Bowdoin College, Brunswick, ME, 04011, USA
| |
Collapse
|
22
|
Turab Naqvi AA, Rahman S, Rubi, Zeya F, Kumar K, Choudhary H, Jamal MS, Kim J, Hassan MI. Genome analysis of Chlamydia trachomatis for functional characterization of hypothetical proteins to discover novel drug targets. Int J Biol Macromol 2016; 96:234-240. [PMID: 27993657 DOI: 10.1016/j.ijbiomac.2016.12.045] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2016] [Revised: 12/05/2016] [Accepted: 12/15/2016] [Indexed: 01/28/2023]
Abstract
C. trachomatis is a Gram-negative bacterium that causes trachoma and sexually transmitted disease (STD) Chlamydia in humans. Chlamydial genital infections are the most frequent among all communicable diseases. The D/UW-3/Cx strain of C. trachomatis contains 935 genes and three pseudogenes. Out of these genes, 887 genes code for proteins while six for rRNA, 37 tRNA, and three genes translate into other RNAs. The proteome of C. trachomatis made of 887 proteins contains 269 Hypothetical proteins (HPs) that are subjected to functional characterization. This study suggests some known methods of functional characterization of such HPs. All of these methods are explicitly used to assign functions to the HPs with the accuracy of more than 90%. After extensive analysis of all the HPs, we have successfully assigned functions to 89 HPs with high precision. In the newly assigned HPs, there are enzymes, transporters, binding proteins, proteins involved in biosynthesis and regulatory processes and proteins with miscellaneous functions. The study suggests that the functionally annotated HPs may play a vital role in the growth and pathogenesis of this organism. Therefore, they can be considered potential drug targets.
Collapse
Affiliation(s)
- Ahmad Abu Turab Naqvi
- Center for Interdisciplinary Research in Basic Sciences, Jamia Millia Islamia, Jamia Nagar, New Delhi 110025, India
| | - Safikur Rahman
- Department of Medical Biotechnology, Yeungnam University, Gyeongsan 712-749, South Korea
| | - Rubi
- Center for Interdisciplinary Research in Basic Sciences, Jamia Millia Islamia, Jamia Nagar, New Delhi 110025, India
| | - Firdaus Zeya
- Department of Computer Science, Jamia Millia Islamia, Jamia Nagar, New Delhi 110025, India
| | - Kundan Kumar
- Center for Interdisciplinary Research in Basic Sciences, Jamia Millia Islamia, Jamia Nagar, New Delhi 110025, India
| | - Hani Choudhary
- Department of Biochemistry, Cancer Metabolism and Epigenetic Unit, Faculty of Science, Center of Innovation in Personalized Medicine, Cancer and Mutagenesis Unit, King Fahd Center for Medical Research, King Abdulaziz University, Jeddah, Saudi Arabia
| | - Mohammad Sarwar Jamal
- King Fahd Medical Research Center, King Abdulaziz University, P.O. Box: 80216, Jeddah 21589, Saudi Arabia
| | - Jihoe Kim
- Department of Medical Biotechnology, Yeungnam University, Gyeongsan 712-749, South Korea.
| | - Md Imtaiyaz Hassan
- Center for Interdisciplinary Research in Basic Sciences, Jamia Millia Islamia, Jamia Nagar, New Delhi 110025, India.
| |
Collapse
|
23
|
Tabbene O, Azaiez S, Di Grazia A, Karkouch I, Ben Slimene I, Elkahoui S, Alfeddy MN, Casciaro B, Luca V, Limam F, Mangoni ML. Bacillomycin D and its combination with amphotericin B: promising antifungal compounds with powerful antibiofilm activity and wound-healing potency. J Appl Microbiol 2016; 120:289-300. [PMID: 26669801 DOI: 10.1111/jam.13030] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2015] [Revised: 11/10/2015] [Accepted: 12/04/2015] [Indexed: 12/31/2022]
Abstract
AIMS In this study, we evaluated the ability of the lipopeptide bacillomycin D and the antifungal drug amphotericin B as well as their combination, to inhibit Candida albicans biofilm formation and to accelerate keratinocyte cell migration. METHODS AND RESULTS The antibiofilm activity of bacillomycin D and its combination with amphotericin B was carried out by crystal violet colorimetric method. Our results have shown that, when combined together at low concentrations nontoxic to mammalian cells, corresponding to 1/32 MIC (0·39 μg ml(-1) ) and 1/4 MIC (0·06 μg ml(-1) ) for bacillomycin D and amphotericin B, respectively, a clear antibiofilm activity is manifested (95% inhibition of biofilm formation) along with a clear inhibition of germ tube formation. Moreover, the effect of both drugs on preformed biofilm of C. albicans strain was determined using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) reduction assay. The combination of the two antifungal compounds at 0·39 and 1 μg ml(-1) for bacillomycin D and amphotericin B, respectively, resulted in a clear enhancement of biofilm eradication compared to the results obtained with each drug alone. Furthermore, this combination was found to promote the closure of a gap produced in a monolayer of human keratinocytes. CONCLUSIONS Bacillomycin D and its combination with amphotericin B display impressive anti-biofilm and wound-healing activities. SIGNIFICANCE AND IMPACT OF THE STUDY Application of the lipopeptide bacillomycin D and the antifungal drug amphotericin B in medical devices may offer a promising alternative for topical treatment of Candida-associated infections in the setting of a wound.
Collapse
Affiliation(s)
- O Tabbene
- Laboratoire des Substances Bioactives, Centre de Biotechnologie de Borj-Cedria, Hammam-Lif, Tunisia
| | - S Azaiez
- Laboratoire des Substances Bioactives, Centre de Biotechnologie de Borj-Cedria, Hammam-Lif, Tunisia
| | - A Di Grazia
- Dipartimento di Scienze Biochimiche, Istituto Pasteur-Fondazione Cenci Bolognetti, Universita' La Sapienza, Rome, Italy
| | - I Karkouch
- Laboratoire des Substances Bioactives, Centre de Biotechnologie de Borj-Cedria, Hammam-Lif, Tunisia
| | - I Ben Slimene
- Laboratoire des Substances Bioactives, Centre de Biotechnologie de Borj-Cedria, Hammam-Lif, Tunisia
| | - S Elkahoui
- Laboratoire des Substances Bioactives, Centre de Biotechnologie de Borj-Cedria, Hammam-Lif, Tunisia
| | - M N Alfeddy
- Laboratoire de Phytobactériologie, UR Agrobiotechnologie, Institut National de Recherches Agronomiques, Marrakech, Morocco
| | - B Casciaro
- Dipartimento di Scienze Biochimiche, Istituto Pasteur-Fondazione Cenci Bolognetti, Universita' La Sapienza, Rome, Italy
| | - V Luca
- Dipartimento di Scienze Biochimiche, Istituto Pasteur-Fondazione Cenci Bolognetti, Universita' La Sapienza, Rome, Italy
| | - F Limam
- Laboratoire des Substances Bioactives, Centre de Biotechnologie de Borj-Cedria, Hammam-Lif, Tunisia
| | - M L Mangoni
- Dipartimento di Scienze Biochimiche, Istituto Pasteur-Fondazione Cenci Bolognetti, Universita' La Sapienza, Rome, Italy
| |
Collapse
|
24
|
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
|
25
|
Vincent BM, Langlois JB, Srinivas R, Lancaster AK, Scherz-Shouval R, Whitesell L, Tidor B, Buchwald SL, Lindquist S. A Fungal-Selective Cytochrome bc 1 Inhibitor Impairs Virulence and Prevents the Evolution of Drug Resistance. Cell Chem Biol 2016; 23:978-991. [PMID: 27524297 DOI: 10.1016/j.chembiol.2016.06.016] [Citation(s) in RCA: 35] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2016] [Revised: 05/23/2016] [Accepted: 06/10/2016] [Indexed: 12/11/2022]
Abstract
To cause disease, a microbial pathogen must adapt to the challenges of its host environment. The leading fungal pathogen Candida albicans colonizes nutrient-poor bodily niches, withstands attack from the immune system, and tolerates treatment with azole antifungals, often evolving resistance. To discover agents that block these adaptive strategies, we screened 300,000 compounds for inhibition of azole tolerance in a drug-resistant Candida isolate. We identified a novel indazole derivative that converts azoles from fungistatic to fungicidal drugs by selective inhibition of mitochondrial cytochrome bc1. We synthesized 103 analogs to optimize potency (half maximal inhibitory concentration 0.4 ?M) and fungal selectivity (28-fold over human). In addition to reducing azole resistance, targeting cytochrome bc1 prevents C. albicans from adapting to the nutrient-deprived macrophage phagosome and greatly curtails its virulence in mice. Inhibiting mitochondrial respiration and restricting metabolic flexibility with this synthetically tractable chemotype provides an attractive therapeutic strategy to limit both fungal virulence and drug resistance.
Collapse
Affiliation(s)
- Benjamin M Vincent
- Microbiology Graduate Program, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, MA 02139, USA; Whitehead Institute for Biomedical Research, 9 Cambridge Center, Cambridge, MA 02142, USA
| | - Jean-Baptiste Langlois
- Department of Chemistry, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Raja Srinivas
- Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, USA; Department of Electrical Engineering and Computer Science, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Alex K Lancaster
- Whitehead Institute for Biomedical Research, 9 Cambridge Center, Cambridge, MA 02142, USA
| | - Ruth Scherz-Shouval
- Whitehead Institute for Biomedical Research, 9 Cambridge Center, Cambridge, MA 02142, USA
| | - Luke Whitesell
- Whitehead Institute for Biomedical Research, 9 Cambridge Center, Cambridge, MA 02142, USA
| | - Bruce Tidor
- Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, USA; Department of Electrical Engineering and Computer Science, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Stephen L Buchwald
- Department of Chemistry, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Susan Lindquist
- Whitehead Institute for Biomedical Research, 9 Cambridge Center, Cambridge, MA 02142, USA; Department of Biology, Howard Hughes Medical Institute, Massachusetts Institute of Technology, Cambridge, MA 02139, USA.
| |
Collapse
|
26
|
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
|
27
|
Shahbaaz M, Bisetty K, Ahmad F, Hassan MI. Towards New Drug Targets? Function Prediction of Putative Proteins of Neisseria meningitidis MC58 and Their Virulence Characterization. OMICS-A JOURNAL OF INTEGRATIVE BIOLOGY 2015; 19:416-34. [PMID: 26076386 DOI: 10.1089/omi.2015.0032] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Neisseria meningitidis is a Gram-negative aerobic diplococcus, responsible for a variety of meningococcal diseases. The genome of N. meningitidis MC58 is comprised of 2114 genes that are translated into 1953 proteins. The 698 genes (∼35%) encode hypothetical proteins (HPs), because no experimental evidence of their biological functions are available. Analyses of these proteins are important to understand their functions in the metabolic networks and may lead to the discovery of novel drug targets against the infections caused by N. meningitidis. This study aimed at the identification and categorization of each HP present in the genome of N. meningitidis MC58 using computational tools. Functions of 363 proteins were predicted with high accuracy among the annotated set of HPs investigated. The reliably predicted 363 HPs were further grouped into 41 different classes of proteins, based on their possible roles in cellular processes such as metabolism, transport, and replication. Our studies revealed that 22 HPs may be involved in the pathogenesis caused by this microorganism. The top two HPs with highest virulence scores were subjected to molecular dynamics (MD) simulations to better understand their conformational behavior in a water environment. We also compared the MD simulation results with other virulent proteins present in N. meningitidis. This study broadens our understanding of the mechanistic pathways of pathogenesis, drug resistance, tolerance, and adaptability for host immune responses to N. meningitidis.
Collapse
Affiliation(s)
- Mohd Shahbaaz
- 1 Department of Chemistry, Durban University of Technology , Durban, South Africa
| | - Krishna Bisetty
- 1 Department of Chemistry, Durban University of Technology , Durban, South Africa
| | - Faizan Ahmad
- 2 Center for Interdisciplinary Research in Basic Sciences , Jamia Millia Islamia, Jamia Nagar, New Delhi, 110025, India
| | - Md Imtaiyaz Hassan
- 2 Center for Interdisciplinary Research in Basic Sciences , Jamia Millia Islamia, Jamia Nagar, New Delhi, 110025, India
| |
Collapse
|
28
|
Abstract
To infect the host and cause disease, many medically important fungi invade normally nonphagocytic host cells, such as endothelial cells and epithelial cells. Host cell invasion is a two-step process consisting of adherence followed by invasion. There are two general mechanisms of host cell invasion, induced endocytosis and active penetration. Furthermore, fungi can traverse epithelial or endothelial cell barriers either by proteolytic degradation of intercellular tight junctions or via a Trojan horse mechanism in which they are transported by leukocytes. Although these mechanisms of host cell invasion have been best studied using Candida albicans and Cryptococcus neoformans, it is probable that other invasive fungi also use one or more of these mechanisms to invade host cells. Identification of these invasion mechanisms holds promise to facilitate the development of new approaches to inhibit fungal invasion and thereby prevent disease.
Collapse
Affiliation(s)
- Donald C Sheppard
- Departments of Microbiology and Immunology and Medicine, McGill University, Montreal, Quebec H3A 2B4, Canada
| | - Scott G Filler
- Los Angeles Biomedical Research Institute at Harbor-UCLA Medical Center, Torrance, California 90502 David Geffen School of Medicine at UCLA, Los Angeles, California 90025
| |
Collapse
|
29
|
Wang L, Tian X, Gyawali R, Upadhyay S, Foyle D, Wang G, Cai JJ, Lin X. Morphotype transition and sexual reproduction are genetically associated in a ubiquitous environmental pathogen. PLoS Pathog 2014; 10:e1004185. [PMID: 24901238 PMCID: PMC4047104 DOI: 10.1371/journal.ppat.1004185] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2014] [Accepted: 04/30/2014] [Indexed: 11/18/2022] Open
Abstract
Sexual reproduction in an environmental pathogen helps maximize its lineage fitness to changing environment and the host. For the fungal pathogen Cryptococcus neoformans, sexual reproduction is proposed to have yielded hyper virulent and drug resistant variants. The life cycle of this pathogen commences with mating, followed by the yeast-hypha transition and hyphal growth, and it concludes with fruiting body differentiation and sporulation. How these sequential differentiation events are orchestrated to ensure developmental continuality is enigmatic. Here we revealed the genetic network of the yeast-to-hypha transition in Cryptococcus by analyzing transcriptomes of populations with a homogeneous morphotype generated by an engineered strain. Among this network, we found that a Pumilio-family protein Pum1 and the matricellular signal Cfl1 represent two major parallel circuits directing the yeast-hypha transition. Interestingly, only Pum1 coordinates the sequential morphogenesis events during a-α bisexual and α unisexual reproduction. Pum1 initiates the yeast-to-hypha transition, partially through a novel filament-specific secretory protein Fas1; Pum1 is also required to sustain hyphal growth after the morphological switch. Furthermore, Pum1 directs subsequent differentiation of aerial hyphae into fruiting bodies in both laboratory and clinical isolates. Pum1 exerts its control on sexual reproduction partly through regulating the temporal expression of Dmc1, the meiosis-specific recombinase. Therefore, Pum1 serves a pivotal role in bridging post-mating morphological differentiation events with sexual reproduction in Cryptococcus. Our findings in Cryptococcus illustrate how an environmental pathogen can ensure the completion of its life cycle to safeguard its long-term lineage success.
Collapse
Affiliation(s)
- Linqi Wang
- Department of Biology, Texas A&M University, College Station, Texas, United States of America
- * E-mail: (LW); (XL)
| | - Xiuyun Tian
- Department of Biology, Texas A&M University, College Station, Texas, United States of America
| | - Rachana Gyawali
- Department of Biology, Texas A&M University, College Station, Texas, United States of America
| | - Srijana Upadhyay
- Department of Biology, Texas A&M University, College Station, Texas, United States of America
| | - Dylan Foyle
- Department of Biology, Texas A&M University, College Station, Texas, United States of America
| | - Gang Wang
- Department of Veterinary Integrative Biosciences, Texas A&M University, College Station, Texas, United States of America
| | - James J. Cai
- Department of Veterinary Integrative Biosciences, Texas A&M University, College Station, Texas, United States of America
| | - Xiaorong Lin
- Department of Biology, Texas A&M University, College Station, Texas, United States of America
- * E-mail: (LW); (XL)
| |
Collapse
|
30
|
Shahbaaz M, Hassan MI, Ahmad F. Functional annotation of conserved hypothetical proteins from Haemophilus influenzae Rd KW20. PLoS One 2013; 8:e84263. [PMID: 24391926 PMCID: PMC3877243 DOI: 10.1371/journal.pone.0084263] [Citation(s) in RCA: 67] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2013] [Accepted: 11/21/2013] [Indexed: 11/18/2022] Open
Abstract
Haemophilus influenzae is a Gram negative bacterium that belongs to the family Pasteurellaceae, causes bacteremia, pneumonia and acute bacterial meningitis in infants. The emergence of multi-drug resistance H. influenzae strain in clinical isolates demands the development of better/new drugs against this pathogen. Our study combines a number of bioinformatics tools for function predictions of previously not assigned proteins in the genome of H. influenzae. This genome was extensively analyzed and found 1,657 functional proteins in which function of 429 proteins are unknown, termed as hypothetical proteins (HPs). Amino acid sequences of all 429 HPs were extensively annotated and we successfully assigned the function to 296 HPs with high confidence. We also characterized the function of 124 HPs precisely, but with less confidence. We believed that sequence of a protein can be used as a framework to explain known functional properties. Here we have combined the latest versions of protein family databases, protein motifs, intrinsic features from the amino acid sequence, pathway and genome context methods to assign a precise function to hypothetical proteins for which no experimental information is available. We found these HPs belong to various classes of proteins such as enzymes, transporters, carriers, receptors, signal transducers, binding proteins, virulence and other proteins. The outcome of this work will be helpful for a better understanding of the mechanism of pathogenesis and in finding novel therapeutic targets for H. influenzae.
Collapse
Affiliation(s)
- Mohd Shahbaaz
- Department of Computer Science, Jamia Millia Islamia, Jamia Nagar, New Delhi, India
| | - Md Imtaiyaz Hassan
- Center for Interdisciplinary Research in Basic Sciences, Jamia Millia Islamia, Jamia Nagar, New Delhi, India
| | - Faizan Ahmad
- Center for Interdisciplinary Research in Basic Sciences, Jamia Millia Islamia, Jamia Nagar, New Delhi, India
| |
Collapse
|
31
|
Theberge S, Semlali A, Alamri A, Leung KP, Rouabhia M. C. albicans growth, transition, biofilm formation, and gene expression modulation by antimicrobial decapeptide KSL-W. BMC Microbiol 2013; 13:246. [PMID: 24195531 PMCID: PMC4229313 DOI: 10.1186/1471-2180-13-246] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2013] [Accepted: 11/04/2013] [Indexed: 01/12/2023] Open
Abstract
Background Antimicrobial peptides have been the focus of much research over the last decade because of their effectiveness and broad-spectrum activity against microbial pathogens. These peptides also participate in inflammation and the innate host defense system by modulating the immune function that promotes immune cell adhesion and migration as well as the respiratory burst, which makes them even more attractive as therapeutic agents. This has led to the synthesis of various antimicrobial peptides, including KSL-W (KKVVFWVKFK-NH2), for potential clinical use. Because this peptide displays antimicrobial activity against bacteria, we sought to determine its antifungal effect on C. albicans. Growth, hyphal form, biofilm formation, and degradation were thus examined along with EFG1, NRG1, EAP1, HWP1, and SAP 2-4-5-6 gene expression by quantitative RT-PCR. Results This study demonstrates that KSL-W markedly reduced C. albicans growth at both early and late incubation times. The significant effect of KSL-W on C. albicans growth was observed beginning at 10 μg/ml after 5 h of contact by reducing C. albicans transition and at 25 μg/ml by completely inhibiting C. albicans transition. Cultured C. albicans under biofilm-inducing conditions revealed that both KSL-W and amphotericin B significantly decreased biofilm formation at 2, 4, and 6 days of culture. KSL-W also disrupted mature C. albicans biofilms. The effect of KSL-W on C. albicans growth, transition, and biofilm formation/disruption may thus occur through gene modulation, as the expression of various genes involved in C. albicans growth, transition and biofilm formation were all downregulated when C. albicans was treated with KSL-W. The effect was greater when C. albicans was cultured under hyphae-inducing conditions. Conclusions These data provide new insight into the efficacy of KSL-W against C. albicans and its potential use as an antifungal therapy.
Collapse
Affiliation(s)
| | | | | | | | - Mahmoud Rouabhia
- Oral Ecology Research Group, Faculty of Dentistry, Laval University, 2420, rue de la Terrasse, Quebec G1V 0A6, QC, Canada.
| |
Collapse
|
32
|
Filler SG. Can host receptors for fungi be targeted for treatment of fungal infections? Trends Microbiol 2013; 21:389-96. [PMID: 23796589 DOI: 10.1016/j.tim.2013.05.006] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2013] [Revised: 05/23/2013] [Accepted: 05/24/2013] [Indexed: 11/19/2022]
Abstract
The invasion and stimulation of normally non-phagocytic host cells, such as epithelial and endothelial cells, is a key step in the pathogenesis of many fungal infections. In most cases, host cell invasion and/or stimulation of a proinflammatory response is induced when proteins or carbohydrates on the fungal cell surface bind to receptors on the host cell. Although many of these fungal-host cell interactions have only been investigated in vitro, the therapeutic efficacy of blocking the host cell receptors for Candida albicans and Rhizopus oryzae has been demonstrated in experimental animal models of infection. We summarize recent studies of the fungal receptors on normally non-phagocytic host cells and the therapeutic implications of blocking these receptors.
Collapse
Affiliation(s)
- Scott G Filler
- Division of Infectious Diseases, Los Angeles Biomedical Research Institute at Harbor-UCLA Medical Center, 1124 West Carson Street, Torrance, CA 90502, USA.
| |
Collapse
|
33
|
Investigation of the function of Candida albicans Als3 by heterologous expression in Candida glabrata. Infect Immun 2013; 81:2528-35. [PMID: 23630968 DOI: 10.1128/iai.00013-13] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
During hematogenously disseminated infection, blood-borne Candida albicans invades the endothelial cell lining of the vasculature to invade the deep tissues. Although the C. albicans Als3 invasin is critical for invasion and damage of endothelial cells in vitro, a C. albicans als3Δ/Δ mutant has normal virulence in the mouse model of disseminated infection. We hypothesized that the contribution of Als3 to virulence is obscured by the presence of additional C. albicans invasins. To elucidate the in vivo function of Als3, we heterologously expressed C. albicans ALS3 in Candida glabrata, a yeast that lacks a close ALS3 ortholog and has low virulence in mice. We found that following intravenous inoculation into mice, the ALS3-expressing strain preferentially trafficked to the brain, where it induced significantly elevated levels of myeloperoxidase, tumor necrosis factor, monocyte chemoattractant protein 1, and gamma interferon. Also, the ALS3-expressing strain had enhanced adherence to and invasion of human brain microvascular endothelial cells in vitro, demonstrating a potential mechanism for ALS3-mediated neurotropism. In addition, upon initiation of infection, the ALS3-expressing strain had increased trafficking to the cortex of the kidneys. With prolonged infection, this strain persisted in the kidneys at significantly higher levels than the control strain but did not induce an elevated inflammatory response. Finally, the ALS3-expressing strain had increased resistance to neutrophil killing in vitro. These results indicate that during disseminated infection, Als3 mediates initial trafficking to the brain and renal cortex and contributes to fungal persistence in the kidneys.
Collapse
|