1
|
Vandermeulen MD, Lorenz MC, Cullen PJ. Conserved signaling modules regulate filamentous growth in fungi: a model for eukaryotic cell differentiation. Genetics 2024:iyae122. [PMID: 39239926 DOI: 10.1093/genetics/iyae122] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2024] [Accepted: 07/20/2024] [Indexed: 09/07/2024] Open
Abstract
Eukaryotic organisms are composed of different cell types with defined shapes and functions. Specific cell types are produced by the process of cell differentiation, which is regulated by signal transduction pathways. Signaling pathways regulate cell differentiation by sensing cues and controlling the expression of target genes whose products generate cell types with specific attributes. In studying how cells differentiate, fungi have proved valuable models because of their ease of genetic manipulation and striking cell morphologies. Many fungal species undergo filamentous growth-a specialized growth pattern where cells produce elongated tube-like projections. Filamentous growth promotes expansion into new environments, including invasion into plant and animal hosts by fungal pathogens. The same signaling pathways that regulate filamentous growth in fungi also control cell differentiation throughout eukaryotes and include highly conserved mitogen-activated protein kinase (MAPK) pathways, which is the focus of this review. In many fungal species, mucin-type sensors regulate MAPK pathways to control filamentous growth in response to diverse stimuli. Once activated, MAPK pathways reorganize cell polarity, induce changes in cell adhesion, and promote the secretion of degradative enzymes that mediate access to new environments. However, MAPK pathway regulation is complicated because related pathways can share components with each other yet induce unique responses (i.e. signal specificity). In addition, MAPK pathways function in highly integrated networks with other regulatory pathways (i.e. signal integration). Here, we discuss signal specificity and integration in several yeast models (mainly Saccharomyces cerevisiae and Candida albicans) by focusing on the filamentation MAPK pathway. Because of the strong evolutionary ties between species, a deeper understanding of the regulation of filamentous growth in established models and increasingly diverse fungal species can reveal fundamentally new mechanisms underlying eukaryotic cell differentiation.
Collapse
Affiliation(s)
| | - Michael C Lorenz
- Department of Microbiology and Molecular Genetics, University of Texas McGovern Medical School, Houston, TX 77030, USA
| | - Paul J Cullen
- Department of Biological Sciences, University at Buffalo, Buffalo, NY 14260-1300, USA
| |
Collapse
|
2
|
Al Mamun MA, Reza MA, Islam MS. Identification of novel proteins regulating lipid droplet biogenesis in filamentous fungi. Mol Microbiol 2023; 120:702-722. [PMID: 37748926 DOI: 10.1111/mmi.15170] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2023] [Revised: 09/06/2023] [Accepted: 09/11/2023] [Indexed: 09/27/2023]
Abstract
Lipid droplets (LDs) are storage organelles for neutral lipids which are critical for lipid homeostasis. Current knowledge of fungal LD biogenesis is largely limited to budding yeast, while LD regulation in multinucleated filamentous fungi which exhibit considerable metabolic activity remains unexplored. In this study, 19 LD-associated proteins were identified in the multinucleated species Aspergillus oryzae using a colocalization screening of a previously established enhanced green fluorescent protein (EGFP) fusion library. Functional screening identified 12 lipid droplet-regulating (LDR) proteins whose loss of function resulted in irregular LD biogenesis, particularly in terms of LD number and size. Bioinformatics analysis, targeted mutagenesis, and microscopy revealed four LDR proteins that localize to LD via the putative amphipathic helices (AHs). Further analysis revealed that LdrA with an Opi1 domain is essential for cytoplasmic and nuclear LD biogenesis involving a novel AH. Phylogenetic analysis demonstrated that the patterns of gene evolution were predominantly based on gene duplication. Our study identified a set of novel proteins involved in the regulation of LD biogenesis, providing unique molecular and evolutionary insights into fungal lipid storage.
Collapse
Affiliation(s)
- Md Abdulla Al Mamun
- Department of Biotechnology, The University of Tokyo, Tokyo, Japan
- Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, Massachusetts, USA
- Program in Cellular and Molecular Medicine, Boston Children's Hospital, Boston, Massachusetts, USA
| | - M Abu Reza
- Department of Genetic Engineering and Biotechnology, University of Rajshahi, Rajshahi, Bangladesh
| | | |
Collapse
|
3
|
Villa S, Hamideh M, Weinstock A, Qasim MN, Hazbun TR, Sellam A, Hernday AD, Thangamani S. Transcriptional control of hyphal morphogenesis in Candida albicans. FEMS Yeast Res 2021; 20:5715912. [PMID: 31981355 PMCID: PMC7000152 DOI: 10.1093/femsyr/foaa005] [Citation(s) in RCA: 38] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2019] [Accepted: 01/31/2020] [Indexed: 12/12/2022] Open
Abstract
Candida albicans is a multimorphic commensal organism and opportunistic fungal pathogen in humans. A morphological switch between unicellular budding yeast and multicellular filamentous hyphal growth forms plays a vital role in the virulence of C. albicans, and this transition is regulated in response to a range of environmental cues that are encountered in distinct host niches. Many unique transcription factors contribute to the transcriptional regulatory network that integrates these distinct environmental cues and determines which phenotypic state will be expressed. These hyphal morphogenesis regulators have been extensively investigated, and represent an increasingly important focus of study, due to their central role in controlling a key C. albicans virulence attribute. This review provides a succinct summary of the transcriptional regulatory factors and environmental signals that control hyphal morphogenesis in C. albicans.
Collapse
Affiliation(s)
- Sonia Villa
- Masters in Biomedical Science Program, Midwestern University, 19555 N. 59th Ave. Glendale, AZ 85308, USA
| | - Mohammad Hamideh
- Masters in Biomedical Science Program, Midwestern University, 19555 N. 59th Ave. Glendale, AZ 85308, USA
| | - Anthony Weinstock
- Arizona College of Osteopathic Medicine, Midwestern University, 19555 N. 59th Ave. Glendale, AZ 85308, USA
| | - Mohammad N Qasim
- Quantitative and Systems Biology Graduate Program, School of Natural Sciences, University of California, Merced, Merced, CA, 95343, USA
| | - Tony R Hazbun
- Department of Medicinal Chemistry and Molecular Pharmacology, College of Pharmacy, Purdue University, West Lafayette, IN 47907, USA
| | - Adnane Sellam
- Department of Microbiology, Infectious Diseases and Immunology, Faculty of Medicine, Université Laval, Quebec City, QC, Canada
| | - Aaron D Hernday
- Quantitative and Systems Biology Graduate Program, School of Natural Sciences, University of California, Merced, Merced, CA, 95343, USA.,Department of Molecular and Cell Biology, School of Natural Sciences, University of California, Merced, Merced, CA, 95343, USA
| | - Shankar Thangamani
- Department of Pathology and Population Medicine, College of Veterinary Medicine, Midwestern University, 19555 N. 59th Ave. Glendale, AZ 85308, USA
| |
Collapse
|
4
|
Qasim MN, Valle Arevalo A, Nobile CJ, Hernday AD. The Roles of Chromatin Accessibility in Regulating the Candida albicans White-Opaque Phenotypic Switch. J Fungi (Basel) 2021; 7:37. [PMID: 33435404 PMCID: PMC7826875 DOI: 10.3390/jof7010037] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2020] [Revised: 01/05/2021] [Accepted: 01/07/2021] [Indexed: 12/18/2022] Open
Abstract
Candida albicans, a diploid polymorphic fungus, has evolved a unique heritable epigenetic program that enables reversible phenotypic switching between two cell types, referred to as "white" and "opaque". These cell types are established and maintained by distinct transcriptional programs that lead to differences in metabolic preferences, mating competencies, cellular morphologies, responses to environmental signals, interactions with the host innate immune system, and expression of approximately 20% of genes in the genome. Transcription factors (defined as sequence specific DNA-binding proteins) that regulate the establishment and heritable maintenance of the white and opaque cell types have been a primary focus of investigation in the field; however, other factors that impact chromatin accessibility, such as histone modifying enzymes, chromatin remodelers, and histone chaperone complexes, also modulate the dynamics of the white-opaque switch and have been much less studied to date. Overall, the white-opaque switch represents an attractive and relatively "simple" model system for understanding the logic and regulatory mechanisms by which heritable cell fate decisions are determined in higher eukaryotes. Here we review recent discoveries on the roles of chromatin accessibility in regulating the C. albicans white-opaque phenotypic switch.
Collapse
Affiliation(s)
- Mohammad N. Qasim
- Department of Molecular and Cell Biology, University of California-Merced, Merced, CA 95343, USA; (M.N.Q.); (A.V.A.); (C.J.N.)
- Quantitative and Systems Biology Graduate Program, University of California-Merced, Merced, CA 95343, USA
| | - Ashley Valle Arevalo
- Department of Molecular and Cell Biology, University of California-Merced, Merced, CA 95343, USA; (M.N.Q.); (A.V.A.); (C.J.N.)
- Quantitative and Systems Biology Graduate Program, University of California-Merced, Merced, CA 95343, USA
| | - Clarissa J. Nobile
- Department of Molecular and Cell Biology, University of California-Merced, Merced, CA 95343, USA; (M.N.Q.); (A.V.A.); (C.J.N.)
- Health Sciences Research Institute, University of California-Merced, Merced, CA 95343, USA
| | - Aaron D. Hernday
- Department of Molecular and Cell Biology, University of California-Merced, Merced, CA 95343, USA; (M.N.Q.); (A.V.A.); (C.J.N.)
- Health Sciences Research Institute, University of California-Merced, Merced, CA 95343, USA
| |
Collapse
|
5
|
Deletion of ADA2 Increases Antifungal Drug Susceptibility and Virulence in Candida glabrata. Antimicrob Agents Chemother 2018; 62:AAC.01924-17. [PMID: 29311082 DOI: 10.1128/aac.01924-17] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2017] [Accepted: 12/15/2017] [Indexed: 12/23/2022] Open
Abstract
Candida glabrata, the second most frequent cause of candidiasis after Candida albicans, is an emerging human fungal pathogen that is intrinsically drug tolerant. Currently, studies of C. glabrata genes involved in drug tolerance are limited. Ada2, a component serving as a transcription adaptor of the Spt-Ada-Gcn5 acetyltransferase (SAGA) complex, is required for antifungal drug tolerance and virulence in C. albicans However, its roles in C. glabrata remain elusive. In this study, we found that ada2 mutants demonstrated severe growth defects at 40°C but only mild defects at 37°C or 25°C. In addition, C. glabrata ada2 mutants exhibited pleiotropic phenotypes, including susceptibility to three classes of antifungal drugs (i.e., azoles, echinocandins, and polyenes) and cell wall-perturbing agents but resistance to the endoplasmic reticulum stressor tunicamycin. According to RNA sequence analysis, the expression of 43 genes was downregulated and the expression of 442 genes was upregulated in the ada2 mutant compared to their expression in the wild type. C. glabrata ADA2, along with its downstream target ERG6, controls antifungal drug tolerance and cell wall integrity. Surprisingly, ada2 mutants were hypervirulent in a murine model of systemic infection, possibly due to the upregulation of multiple adhesin-like genes, increased agar invasion, and overstimulation of murine tumor necrosis factor alpha production.
Collapse
|
6
|
Yu SJ, Chang YL, Chen YL. Calcineurin signaling: lessons from Candida species. FEMS Yeast Res 2015; 15:fov016. [DOI: 10.1093/femsyr/fov016] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/06/2015] [Indexed: 12/24/2022] Open
|