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Garaiova M, Ding Y, Holic R, Valachovic M, Zhang C, Hapala I, Liu P. Yeast perilipin Pet10p/Pln1p interacts with Erg6p in ergosterol metabolism. Biochim Biophys Acta Mol Cell Biol Lipids 2024; 1869:159506. [PMID: 38734059 DOI: 10.1016/j.bbalip.2024.159506] [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: 05/06/2023] [Revised: 05/03/2024] [Accepted: 05/08/2024] [Indexed: 05/13/2024]
Abstract
Lipid droplets (LD) are highly dynamic organelles specialized for the regulation of energy storage and cellular homeostasis. LD consist of a neutral lipid core surrounded by a phospholipid monolayer membrane with embedded proteins, most of which are involved in lipid homeostasis. In this study, we focused on one of the major LD proteins, sterol C24-methyltransferase, encoded by ERG6. We found that the absence of Erg6p resulted in an increased accumulation of yeast perilipin Pet10p in LD, while the disruption of PET10 was accompanied by Erg6p LD over-accumulation. An observed reciprocal enrichment of Erg6p and Pet10p in pet10Δ and erg6Δ mutants in LD, respectively, was related to specific functional changes in the LD and was not due to regulation on the expression level. The involvement of Pet10p in neutral lipid homeostasis was observed in experiments that focused on the dynamics of neutral lipid mobilization as time-dependent changes in the triacylglycerols (TAG) and steryl esters (SE) content. We found that the kinetics of SE hydrolysis was reduced in erg6Δ cells and the mobilization of SE was completely lost in mutants that lacked both Erg6p and Pet10p. In addition, we observed that decreased levels of SE in erg6Δpet10Δ was linked to an overexpression of steryl ester hydrolase Yeh1p. Lipid analysis of erg6Δpet10Δ showed that PET10 deletion altered the composition of ergosterol intermediates which had accumulated in erg6Δ. In conclusion, yeast perilipin Pet10p functionally interacts with Erg6p during the metabolism of ergosterol.
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Affiliation(s)
- Martina Garaiova
- Department of Biochemistry of Biomembranes, Institute of Animal Biochemistry and Genetics, Centre of Biosciences, Slovak Academy of Sciences, Dubravska cesta 9, Bratislava 840 05, Slovakia.
| | - Yunfeng Ding
- National Laboratory of Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China
| | - Roman Holic
- Department of Biochemistry of Biomembranes, Institute of Animal Biochemistry and Genetics, Centre of Biosciences, Slovak Academy of Sciences, Dubravska cesta 9, Bratislava 840 05, Slovakia
| | - Martin Valachovic
- Department of Biochemistry of Biomembranes, Institute of Animal Biochemistry and Genetics, Centre of Biosciences, Slovak Academy of Sciences, Dubravska cesta 9, Bratislava 840 05, Slovakia
| | - Congyan Zhang
- National Laboratory of Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China
| | - Ivan Hapala
- Department of Biochemistry of Biomembranes, Institute of Animal Biochemistry and Genetics, Centre of Biosciences, Slovak Academy of Sciences, Dubravska cesta 9, Bratislava 840 05, Slovakia
| | - Pingsheng Liu
- National Laboratory of Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China; University of Chinese Academy of Sciences, Beijing 100049, China.
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2
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Rahi V, Kaundal RK. Exploring the intricacies of calcium dysregulation in ischemic stroke: Insights into neuronal cell death and therapeutic strategies. Life Sci 2024; 347:122651. [PMID: 38642844 DOI: 10.1016/j.lfs.2024.122651] [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: 01/03/2024] [Revised: 03/16/2024] [Accepted: 04/15/2024] [Indexed: 04/22/2024]
Abstract
Calcium ion (Ca2+) dysregulation is one of the main causes of neuronal cell death and brain damage after cerebral ischemia. During ischemic stroke, the ability of neurons to maintain Ca2+ homeostasis is compromised. Ca2+ regulates various functions of the nervous system, including neuronal activity and adenosine triphosphate (ATP) production. Disruptions in Ca2+ homeostasis can trigger a cascade of events, including activation of the unfolded protein response (UPR) pathway, which is associated with endoplasmic reticulum (ER) stress and mitochondrial dysfunction. This response occurs when the cell is unable to manage protein folding within the ER due to various stressors, such as a high influx of Ca2+. Consequently, the UPR is initiated to restore ER function and alleviate stress, but prolonged activation can lead to mitochondrial dysfunction and, ultimately, cell death. Hence, precise regulation of Ca2+ within the cell is mandatory. The ER and mitochondria are two such organelles that maintain intracellular Ca2+ homeostasis through various calcium-operating channels, including ryanodine receptors (RyRs), inositol trisphosphate receptors (IP3Rs), sarco/endoplasmic reticulum calcium ATPases (SERCAs), the mitochondrial Na+/Ca2+ exchanger (NCLX), the mitochondrial calcium uniporter (MCU) and voltage-dependent anion channels (VDACs). These channels utilize Ca2+ sequestering and release mechanisms to maintain intracellular Ca2+ homeostasis and ensure proper cellular function and survival. The present review critically evaluates the significance of Ca2+ and its physiological role in cerebral ischemia. We have compiled recent findings on calcium's role and emerging treatment strategies, particularly targeting mitochondria and the endoplasmic reticulum, to address Ca2+ overload in cerebral ischemia.
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Affiliation(s)
- Vikrant Rahi
- Department of Pharmacology & Toxicology, National Institute of Pharmaceutical Education and Research-Raebareli, Lucknow 226 002, India
| | - Ravinder K Kaundal
- Department of Pharmacology & Toxicology, National Institute of Pharmaceutical Education and Research-Raebareli, Lucknow 226 002, India.
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3
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Findinier J, Joubert LM, Schmid MF, Malkovskiy A, Chiu W, Burlacot A, Grossman AR. Dramatic Changes in Mitochondrial Subcellular Location and Morphology Accompany Activation of the CO 2 Concentrating Mechanism. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.03.25.586705. [PMID: 38585955 PMCID: PMC10996633 DOI: 10.1101/2024.03.25.586705] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/09/2024]
Abstract
Dynamic changes in intracellular ultrastructure can be critical for the ability of organisms to acclimate to environmental conditions. Microalgae, which are responsible for ~50% of global photosynthesis, compartmentalize their Rubisco into a specialized structure known as the pyrenoid when the cells experience limiting CO2 conditions; this compartmentalization appears to be a component of the CO2 Concentrating Mechanism (CCM), which facilitates photosynthetic CO2 fixation as environmental levels of inorganic carbon (Ci) decline. Changes in the spatial distribution of mitochondria in green algae have also been observed under CO2 limiting conditions, although a role for this reorganization in CCM function remains unclear. We used the green microalgae Chlamydomonas reinhardtii to monitor changes in the position and ultrastructure of mitochondrial membranes as cells transition between high CO2 (HC) and Low/Very Low CO2 (LC/VLC). Upon transferring cells to VLC, the mitochondria move from a central to a peripheral location, become wedged between the plasma membrane and chloroplast envelope, and mitochondrial membranes orient in parallel tubular arrays that extend from the cell's apex to its base. We show that these ultrastructural changes require protein and RNA synthesis, occur within 90 min of shifting cells to VLC conditions, correlate with CCM induction and are regulated by the CCM master regulator CIA5. The apico-basal orientation of the mitochondrial membrane, but not the movement of the mitochondrion to the cell periphery, is dependent on microtubules and the MIRO1 protein, which is involved in membrane-microtubule interactions. Furthermore, blocking mitochondrial electron transport in VLC acclimated cells reduces the cell's affinity for inorganic carbon. Overall, our results suggest that CIA5-dependent mitochondrial repositioning/reorientation functions in integrating cellular architecture and energetics with CCM activities and invite further exploration of how intracellular architecture can impact fitness under dynamic environmental conditions.
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Affiliation(s)
- Justin Findinier
- The Carnegie Institution for Science, Biosphere Sciences & Engineering, Stanford, CA 94305, USA
| | - Lydia-Marie Joubert
- SLAC National Accelerator Laboratory, Division of CryoEM and Bioimaging, Menlo Park, CA 94025, USA
| | - Michael F. Schmid
- SLAC National Accelerator Laboratory, Division of CryoEM and Bioimaging, Menlo Park, CA 94025, USA
| | - Andrey Malkovskiy
- The Carnegie Institution for Science, Biosphere Sciences & Engineering, Stanford, CA 94305, USA
| | - Wah Chiu
- SLAC National Accelerator Laboratory, Division of CryoEM and Bioimaging, Menlo Park, CA 94025, USA
- Stanford University, Department of Bioengineering, Stanford, CA 94305, USA
| | - Adrien Burlacot
- The Carnegie Institution for Science, Biosphere Sciences & Engineering, Stanford, CA 94305, USA
- Stanford University, Biology Department, Stanford, CA 94305, USA
| | - Arthur R. Grossman
- The Carnegie Institution for Science, Biosphere Sciences & Engineering, Stanford, CA 94305, USA
- Stanford University, Biology Department, Stanford, CA 94305, USA
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4
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Benaroya H. Mitochondria and MICOS - function and modeling. Rev Neurosci 2024; 0:revneuro-2024-0004. [PMID: 38369708 DOI: 10.1515/revneuro-2024-0004] [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: 01/10/2024] [Accepted: 01/14/2024] [Indexed: 02/20/2024]
Abstract
An extensive review is presented on mitochondrial structure and function, mitochondrial proteins, the outer and inner membranes, cristae, the role of F1FO-ATP synthase, the mitochondrial contact site and cristae organizing system (MICOS), the sorting and assembly machinery morphology and function, and phospholipids, in particular cardiolipin. Aspects of mitochondrial regulation under physiological and pathological conditions are outlined, in particular the role of dysregulated MICOS protein subunit Mic60 in Parkinson's disease, the relations between mitochondrial quality control and proteins, and mitochondria as signaling organelles. A mathematical modeling approach of cristae and MICOS using mechanical beam theory is introduced and outlined. The proposed modeling is based on the premise that an optimization framework can be used for a better understanding of critical mitochondrial function and also to better map certain experiments and clinical interventions.
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Affiliation(s)
- Haym Benaroya
- Department of Mechanical and Aerospace Engineering, Rutgers University, 98 Brett Road, Piscataway, NJ 08854, USA
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5
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Bui THD, Labedzka-Dmoch K. RetroGREAT signaling: The lessons we learn from yeast. IUBMB Life 2024; 76:26-37. [PMID: 37565710 DOI: 10.1002/iub.2775] [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: 04/28/2023] [Accepted: 07/13/2023] [Indexed: 08/12/2023]
Abstract
The mitochondrial retrograde signaling (RTG) pathway of communication from mitochondria to the nucleus was first studied in yeast Saccharomyces cerevisiae. It rewires cellular metabolism according to the mitochondrial state by reprogramming nuclear gene expression in response to mitochondrial triggers. The main players involved in retrograde signaling are the Rtg1 and Rtg3 transcription factors, and a set of positive and negative regulators, including the Rtg2, Mks1, Lst8, and Bmh1/2 proteins. Retrograde regulation is integrated with other processes, including stress response, osmoregulation, and nutrient sensing through functional crosstalk with cellular pathways such as high osmolarity glycerol or target of rapamycin signaling. In this review, we summarize metabolic changes observed upon retrograde stimulation and analyze the progress made to uncover the mechanisms underlying the integration of regulatory circuits. Comparisons of the evolutionary adaptations of the retrograde pathway that have occurred in the different yeast groups can help to fully understand the process.
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Affiliation(s)
- Thi Hoang Diu Bui
- Institute of Genetics and Biotechnology, Faculty of Biology, University of Warsaw, Warsaw, Poland
| | - Karolina Labedzka-Dmoch
- Institute of Genetics and Biotechnology, Faculty of Biology, University of Warsaw, Warsaw, Poland
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6
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Zhang SX, Wang JJ, Starr CR, Lee EJ, Park KS, Zhylkibayev A, Medina A, Lin JH, Gorbatyuk M. The endoplasmic reticulum: Homeostasis and crosstalk in retinal health and disease. Prog Retin Eye Res 2024; 98:101231. [PMID: 38092262 PMCID: PMC11056313 DOI: 10.1016/j.preteyeres.2023.101231] [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: 08/21/2023] [Revised: 12/05/2023] [Accepted: 12/06/2023] [Indexed: 12/19/2023]
Abstract
The endoplasmic reticulum (ER) is the largest intracellular organelle carrying out a broad range of important cellular functions including protein biosynthesis, folding, and trafficking, lipid and sterol biosynthesis, carbohydrate metabolism, and calcium storage and gated release. In addition, the ER makes close contact with multiple intracellular organelles such as mitochondria and the plasma membrane to actively regulate the biogenesis, remodeling, and function of these organelles. Therefore, maintaining a homeostatic and functional ER is critical for the survival and function of cells. This vital process is implemented through well-orchestrated signaling pathways of the unfolded protein response (UPR). The UPR is activated when misfolded or unfolded proteins accumulate in the ER, a condition known as ER stress, and functions to restore ER homeostasis thus promoting cell survival. However, prolonged activation or dysregulation of the UPR can lead to cell death and other detrimental events such as inflammation and oxidative stress; these processes are implicated in the pathogenesis of many human diseases including retinal disorders. In this review manuscript, we discuss the unique features of the ER and ER stress signaling in the retina and retinal neurons and describe recent advances in the research to uncover the role of ER stress signaling in neurodegenerative retinal diseases including age-related macular degeneration, inherited retinal degeneration, achromatopsia and cone diseases, and diabetic retinopathy. In some chapters, we highlight the complex interactions between the ER and other intracellular organelles focusing on mitochondria and illustrate how ER stress signaling regulates common cellular stress pathways such as autophagy. We also touch upon the integrated stress response in retinal degeneration and diabetic retinopathy. Finally, we provide an update on the current development of pharmacological agents targeting the UPR response and discuss some unresolved questions and knowledge gaps to be addressed by future research.
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Affiliation(s)
- Sarah X Zhang
- Department of Ophthalmology and Ross Eye Institute, Jacobs School of Medicine and Biomedical Sciences, University at Buffalo, State University of New York, Buffalo, NY, United States; Department of Biochemistry, Jacobs School of Medicine and Biomedical Sciences, University at Buffalo, State University of New York, Buffalo, NY, United States.
| | - Josh J Wang
- Department of Ophthalmology and Ross Eye Institute, Jacobs School of Medicine and Biomedical Sciences, University at Buffalo, State University of New York, Buffalo, NY, United States
| | - Christopher R Starr
- Department of Optometry and Vision Science, University of Alabama at Birmingham, Birmingham, AL, United States
| | - Eun-Jin Lee
- Department of Ophthalmology and Byers Eye Institute, Stanford University, Stanford, CA, United States; VA Palo Alto Healthcare System, Palo Alto, CA, United States; Department of Pathology, Stanford University, Stanford, CA, United States
| | - Karen Sophia Park
- Department of Ophthalmology and Ross Eye Institute, Jacobs School of Medicine and Biomedical Sciences, University at Buffalo, State University of New York, Buffalo, NY, United States
| | - Assylbek Zhylkibayev
- Department of Optometry and Vision Science, University of Alabama at Birmingham, Birmingham, AL, United States
| | - Andy Medina
- Department of Ophthalmology and Ross Eye Institute, Jacobs School of Medicine and Biomedical Sciences, University at Buffalo, State University of New York, Buffalo, NY, United States
| | - Jonathan H Lin
- Department of Ophthalmology and Byers Eye Institute, Stanford University, Stanford, CA, United States; VA Palo Alto Healthcare System, Palo Alto, CA, United States; Department of Pathology, Stanford University, Stanford, CA, United States
| | - Marina Gorbatyuk
- Department of Optometry and Vision Science, University of Alabama at Birmingham, Birmingham, AL, United States
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7
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Anjum S, Srivastava S, Panigrahi L, Ansari UA, Trivedi AK, Ahmed S. TORC1 mediated regulation of mitochondrial integrity and calcium ion homeostasis by Wat1/mLst8 in S. pombe. Int J Biol Macromol 2023; 253:126907. [PMID: 37717872 DOI: 10.1016/j.ijbiomac.2023.126907] [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: 05/18/2023] [Revised: 07/18/2023] [Accepted: 09/12/2023] [Indexed: 09/19/2023]
Abstract
The mTOR complexes play a fundamental role in mitochondrial biogenesis and cellular homeostasis. Wat1, an ortholog of mammalian Lst8 is an important component of TOR complex and is essential for the regulation of downstream signaling. Earlier we reported the role of Wat1 in oxidative stress response. Here, we have shown that the abrogation of wat1 causes respiratory defects and mitochondrial depolarization that leads to a decrease in ATP production. The confocal and electron microscopy in wat1Δ cells revealed the fragmented mitochondrial morphology implying its role in mitochondrial fission. Furthermore, we also showed its role in autophagy and the maintenance of calcium ion homeostasis. Additionally, tor2-287 mutant cells also exhibit defects in mitochondrial integrity indicating the TORC1-dependent involvement of Wat1 in the maintenance of mitochondrial homeostasis. The interaction studies of Wat1 and Tor2 with Por1 and Mmm1 proteins revealed a plausible cross-talk between mitochondria and endoplasmic reticulum through the Mitochondria-associated membranes (MAM) and endoplasmic reticulum-mitochondria encounter structure (ERMES) complex, involving TORC1. Taken together, this study demonstrates the involvement of Wat1/mLst8 in harmonizing various mitochondrial functions, redox status, and Ca2+ homeostasis.
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Affiliation(s)
- Simmi Anjum
- Biochemistry and Structural Biology Division, CSIR- Central Drug Research Institute, Sector 10, Jankipuram Extension, Sitapur Road, Lucknow 226031, India; Academy of Scientific and Innovative Research (AcSIR), Ghaziabad 201002, India
| | - Swati Srivastava
- Division of Cancer Biology, CSIR- Central Drug Research Institute, Sector 10, Jankipuram Extension, Sitapur Road, Lucknow 226031, India
| | - Lalita Panigrahi
- Biochemistry and Structural Biology Division, CSIR- Central Drug Research Institute, Sector 10, Jankipuram Extension, Sitapur Road, Lucknow 226031, India
| | - Uzair Ahmad Ansari
- System Toxicology and Health Risk Assessment Group, CSIR- Indian Institute of Toxicological Research, Vishvigyan Bhawan, Lucknow, India; Academy of Scientific and Innovative Research (AcSIR), Ghaziabad 201002, India
| | - Arun Kumar Trivedi
- Division of Cancer Biology, CSIR- Central Drug Research Institute, Sector 10, Jankipuram Extension, Sitapur Road, Lucknow 226031, India; Academy of Scientific and Innovative Research (AcSIR), Ghaziabad 201002, India
| | - Shakil Ahmed
- Biochemistry and Structural Biology Division, CSIR- Central Drug Research Institute, Sector 10, Jankipuram Extension, Sitapur Road, Lucknow 226031, India; Academy of Scientific and Innovative Research (AcSIR), Ghaziabad 201002, India.
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8
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Yan X, Zhang Q, Ma X, Zhong Y, Tang H, Mai S. The mechanism of biomineralization: Progress in mineralization from intracellular generation to extracellular deposition. JAPANESE DENTAL SCIENCE REVIEW 2023; 59:181-190. [PMID: 37388714 PMCID: PMC10302165 DOI: 10.1016/j.jdsr.2023.06.005] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2023] [Revised: 06/01/2023] [Accepted: 06/13/2023] [Indexed: 07/01/2023] Open
Abstract
Biomineralization is a highly regulated process that results in the deposition of minerals in a precise manner, ultimately producing skeletal and dental hard tissues. Recent studies have highlighted the crucial role played by intracellular processes in initiating biomineralization. These processes involve various organelles, such as the endoplasmic reticulum(ER), mitochondria, and lysosomes, in the formation, accumulation, maturation, and secretion of calcium phosphate (CaP) particles. Particularly, the recent in-depth study of the dynamic process of the formation of amorphous calcium phosphate(ACP) precursors among organelles has made great progress in the development of the integrity of the biomineralization chain. However, the precise mechanisms underlying these intracellular processes remain unclear, and they cannot be fully integrated with the extracellular mineralization mechanism and the physicochemical structure development of the mineralization particles. In this review, we aim to focus on the recent progress made in understanding intracellular mineralization organelles' processes and their relationship with the physicochemical structure development of CaP and extracellular deposition of CaP particles.
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Affiliation(s)
- Xin Yan
- Hospital of Stomatology, Sun Yat-sen University, Guangzhou, China
- Guangdong Provincial Key Laboratory of Stomatology, Guangzhou, China
- Institute of Stomatology, Sun Yat-sen University, Guangzhou, China
| | - Qi Zhang
- Hospital of Stomatology, Sun Yat-sen University, Guangzhou, China
- Guangdong Provincial Key Laboratory of Stomatology, Guangzhou, China
- Institute of Stomatology, Sun Yat-sen University, Guangzhou, China
| | - Xinyue Ma
- Hospital of Stomatology, Sun Yat-sen University, Guangzhou, China
- Guangdong Provincial Key Laboratory of Stomatology, Guangzhou, China
- Institute of Stomatology, Sun Yat-sen University, Guangzhou, China
| | - Yewen Zhong
- Hospital of Stomatology, Sun Yat-sen University, Guangzhou, China
- Guangdong Provincial Key Laboratory of Stomatology, Guangzhou, China
- Institute of Stomatology, Sun Yat-sen University, Guangzhou, China
| | - Hengni Tang
- Hospital of Stomatology, Sun Yat-sen University, Guangzhou, China
- Guangdong Provincial Key Laboratory of Stomatology, Guangzhou, China
- Institute of Stomatology, Sun Yat-sen University, Guangzhou, China
| | - Sui Mai
- Hospital of Stomatology, Sun Yat-sen University, Guangzhou, China
- Guangdong Provincial Key Laboratory of Stomatology, Guangzhou, China
- Institute of Stomatology, Sun Yat-sen University, Guangzhou, China
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9
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Aoki K, Yamamoto K, Ohkuma M, Sugita T, Tanaka N, Takashima M. Hyphal Growth in Trichosporon asahii Is Accelerated by the Addition of Magnesium. Microbiol Spectr 2023; 11:e0424222. [PMID: 37102973 PMCID: PMC10269644 DOI: 10.1128/spectrum.04242-22] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2022] [Accepted: 04/10/2023] [Indexed: 04/28/2023] Open
Abstract
Fungal dimorphism involves two morphologies: a unicellular yeast cell and a multicellular hyphal form. Invasion of hyphae into human cells causes severe opportunistic infections. The transition between yeast and hyphal forms is associated with the virulence of fungi; however, the mechanism is poorly understood. Therefore, we aimed to identify factors that induce hyphal growth of Trichosporon asahii, a dimorphic basidiomycete that causes trichosporonosis. T. asahii showed poor growth and formed small cells containing large lipid droplets and fragmented mitochondria when cultivated for 16 h in a nutrient-deficient liquid medium. However, these phenotypes were suppressed via the addition of yeast nitrogen base. When T. asahii cells were cultivated in the presence of different compounds present in the yeast nitrogen base, we found that magnesium sulfate was a key factor for inducing cell elongation, and its addition dramatically restored hyphal growth in T. asahii. In T. asahii hyphae, vacuoles were enlarged, the size of lipid droplets was decreased, and mitochondria were distributed throughout the cell cytoplasm and adjacent to the cell walls. Additionally, hyphal growth was disrupted due to treatment with an actin inhibitor. The actin inhibitor latrunculin A disrupted the mitochondrial distribution even in hyphal cells. Furthermore, magnesium sulfate treatment accelerated hyphal growth in T. asahii for 72 h when the cells were cultivated in a nutrient-deficient liquid medium. Collectively, our results suggest that an increase in magnesium levels triggers the transition from the yeast to hyphal form in T. asahii. These findings will support studies on the pathogenesis of fungi and aid in developing treatments. IMPORTANCE Understanding the mechanism underlying fungal dimorphism is crucial to discern its invasion into human cells. Invasion is caused by the hyphal form rather than the yeast form; therefore, it is important to understand the mechanism of transition from the yeast to hyphal form. To study the transition mechanism, we utilized Trichosporon asahii, a dimorphic basidiomycete that causes severe trichosporonosis since there are fewer studies on T. asahii than on ascomycetes. This study suggests that an increase in Mg2+, the most abundant mineral in living cells, triggers growth of filamentous hyphae and increases the distribution of mitochondria throughout the cell cytoplasm and adjacent to the cell walls in T. asahii. Understanding the mechanism of hyphal growth triggered by Mg2+ increase will provide a model system to explore fungal pathogenicity in the future.
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Affiliation(s)
- Keita Aoki
- Laboratory of Yeast Systematics, Tokyo NODAI Research Institute, Tokyo University of Agriculture, Setagaya, Tokyo, Japan
| | - Kosuke Yamamoto
- Department of Molecular Microbiology, Faculty of Life Sciences, Tokyo University of Agriculture, Setagaya, Tokyo, Japan
| | - Moriya Ohkuma
- Japan Collection of Microorganisms, RIKEN BioResource Research Center, Tsukuba, Ibaraki, Japan
| | - Takashi Sugita
- Department of Microbiology, Meiji Pharmaceutical University, Kiyose, Tokyo, Japan
| | - Naoto Tanaka
- Department of Molecular Microbiology, Faculty of Life Sciences, Tokyo University of Agriculture, Setagaya, Tokyo, Japan
| | - Masako Takashima
- Laboratory of Yeast Systematics, Tokyo NODAI Research Institute, Tokyo University of Agriculture, Setagaya, Tokyo, Japan
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10
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Sing TL, Brar GA, Ünal E. Gametogenesis: Exploring an Endogenous Rejuvenation Program to Understand Cellular Aging and Quality Control. Annu Rev Genet 2022; 56:89-112. [PMID: 35878627 PMCID: PMC9712276 DOI: 10.1146/annurev-genet-080320-025104] [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] [Indexed: 01/07/2023]
Abstract
Gametogenesis is a conserved developmental program whereby a diploid progenitor cell differentiates into haploid gametes, the precursors for sexually reproducing organisms. In addition to ploidy reduction and extensive organelle remodeling, gametogenesis naturally rejuvenates the ensuing gametes, leading to resetting of life span. Excitingly, ectopic expression of the gametogenesis-specific transcription factor Ndt80 is sufficient to extend life span in mitotically dividing budding yeast, suggesting that meiotic rejuvenation pathways can be repurposed outside of their natural context. In this review, we highlight recent studies of gametogenesis that provide emerging insight into natural quality control, organelle remodeling, and rejuvenation strategies that exist within a cell. These include selective inheritance, programmed degradation, and de novo synthesis, all of which are governed by the meiotic gene expression program entailing many forms of noncanonical gene regulation. Finally, we highlight critical questions that remain in the field and provide perspective on the implications of gametogenesis research on human health span.
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Affiliation(s)
- Tina L Sing
- Department of Molecular and Cell Biology, University of California, Berkeley, California, USA;
| | - Gloria A Brar
- Department of Molecular and Cell Biology, University of California, Berkeley, California, USA;
| | - Elçin Ünal
- Department of Molecular and Cell Biology, University of California, Berkeley, California, USA;
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11
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Bittner E, Stehlik T, Freitag J. Sharing the wealth: The versatility of proteins targeted to peroxisomes and other organelles. Front Cell Dev Biol 2022; 10:934331. [PMID: 36225313 PMCID: PMC9549241 DOI: 10.3389/fcell.2022.934331] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2022] [Accepted: 07/27/2022] [Indexed: 11/13/2022] Open
Abstract
Peroxisomes are eukaryotic organelles with critical functions in cellular energy and lipid metabolism. Depending on the organism, cell type, and developmental stage, they are involved in numerous other metabolic and regulatory pathways. Many peroxisomal functions require factors also relevant to other cellular compartments. Here, we review proteins shared by peroxisomes and at least one different site within the cell. We discuss the mechanisms to achieve dual targeting, their regulation, and functional consequences. Characterization of dual targeting is fundamental to understand how peroxisomes are integrated into the metabolic and regulatory circuits of eukaryotic cells.
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12
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Liu J, Yang J. Mitochondria-associated membranes: A hub for neurodegenerative diseases. Biomed Pharmacother 2022; 149:112890. [PMID: 35367757 DOI: 10.1016/j.biopha.2022.112890] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2022] [Revised: 03/24/2022] [Accepted: 03/24/2022] [Indexed: 11/02/2022] Open
Abstract
In eukaryotic cells, organelles could coordinate complex mechanisms of signaling transduction metabolism and gene expression through their functional interactions. The functional domain between ER and mitochondria, called mitochondria-associated membranes (MAM), is closely associated with various physiological functions including intracellular lipid transport, Ca2+ transfer, mitochondria function maintenance, and autophagosome formation. In addition, more evidence suggests that MAM modulate cellular functions in health and disease. Studies have also demonstrated the association of MAM with numerous diseases, including neurodegenerative diseases, cancer, viral infection, obesity, and diabetes. In fact, recent evidence revealed a close relationship of MAM with Alzheimer's disease (AD), Parkinson's disease (PD), Huntington's disease (HD), amyotrophic lateral sclerosis (ALS), and other neurodegenerative diseases. In this view, elucidating the role of MAM in neurodegenerative diseases is particularly important. This review will focus the main tethering protein complexes of MAM and functions of MAM. Besides, the role of MAM in the regulation of neurodegenerative diseases and the potential molecular mechanisms is introduced to provide a new understanding of the pathogenesis of these diseases.
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Affiliation(s)
- Jinxuan Liu
- Department of Toxicology, School of Public Health, China Medical University, NO.77 Puhe road, Shenyang North New Area, Shenyang, 110122, People's Republic of China.
| | - Jinghua Yang
- Department of Toxicology, School of Public Health, China Medical University, NO.77 Puhe road, Shenyang North New Area, Shenyang, 110122, People's Republic of China.
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13
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Mao X, Peng L, Yang L, Zhu M, Du J, Ma C, Yu Q, Li M. Vacuole and mitochondria patch (vCLAMP) and ER-mitochondria encounter structure (ERMES) maintain cell survival by protecting mitochondrial functions in Candida albicans. Biochem Biophys Res Commun 2022; 591:88-94. [PMID: 34999259 DOI: 10.1016/j.bbrc.2021.12.116] [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: 10/19/2021] [Revised: 12/20/2021] [Accepted: 12/30/2021] [Indexed: 11/26/2022]
Abstract
Candida albicans is an important opportunistic fungus in the clinic. In recent years, with the widespread use of antibiotics, drug-resistant strains have been isolated in the clinic, so finding new drug targets has become an urgent problem to be solved. The vacuole and mitochondria patch (vCLAMP) and the ER-mitochondria encounter structure (ERMES) are new types of inner membrane junction systems in Saccharomyces cerevisiae. However, the functions in maintaining cell survival of the two structures have not yet been elucidated in C. albicans. In this study, VAM6 and MDM34 knockout mutants (vam6Δ/Δmet-MDM34) were constructed using an induction system regulated by the MET3 promoter. PI-positive assays showed that deletion of vCLAMP and ERMES led to abnormal growth of C. albicans. Furthermore, the vam6Δ/Δmet-MDM34 mutant exhibited obvious mitochondrial fragmentation, mtDNA damage, reduced ATP levels, and abnormal mitochondrial membrane potential, indicating its important role in maintaining the structures and functions of mitochondria. Moreover, deletion of vCLAMP and ERMES inhibited filamentous growth. Overall This study shows that vCLAMP and ERMES play important roles in maintaining the survival of C. albicans cells.
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Affiliation(s)
- Xiaolong Mao
- Key Laboratory of Molecular Microbiology and Technology, Ministry of Education, College of Life Science, Nankai University, Tianjin, 300071, China; School of Laboratory Animal & Shandong Laboratory Animal Center, Shandong First Medical University & Shandong Academy of Medical Sciences, Shandong, 250000, China
| | - Liping Peng
- Key Laboratory of Molecular Microbiology and Technology, Ministry of Education, College of Life Science, Nankai University, Tianjin, 300071, China
| | - Li Yang
- Key Laboratory of Molecular Microbiology and Technology, Ministry of Education, College of Life Science, Nankai University, Tianjin, 300071, China
| | - Mengsen Zhu
- Key Laboratory of Molecular Microbiology and Technology, Ministry of Education, College of Life Science, Nankai University, Tianjin, 300071, China
| | - Jiawen Du
- Key Laboratory of Molecular Microbiology and Technology, Ministry of Education, College of Life Science, Nankai University, Tianjin, 300071, China
| | - Congcong Ma
- Key Laboratory of Molecular Microbiology and Technology, Ministry of Education, College of Life Science, Nankai University, Tianjin, 300071, China
| | - Qilin Yu
- Key Laboratory of Molecular Microbiology and Technology, Ministry of Education, College of Life Science, Nankai University, Tianjin, 300071, China.
| | - Mingchun Li
- Key Laboratory of Molecular Microbiology and Technology, Ministry of Education, College of Life Science, Nankai University, Tianjin, 300071, China.
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14
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Eisenberg-Bord M, Zung N, Collado J, Drwesh L, Fenech EJ, Fadel A, Dezorella N, Bykov YS, Rapaport D, Fernandez-Busnadiego R, Schuldiner M. Cnm1 mediates nucleus-mitochondria contact site formation in response to phospholipid levels. J Cell Biol 2021; 220:212719. [PMID: 34694322 PMCID: PMC8548916 DOI: 10.1083/jcb.202104100] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2021] [Revised: 08/12/2021] [Accepted: 09/21/2021] [Indexed: 12/12/2022] Open
Abstract
Mitochondrial functions are tightly regulated by nuclear activity, requiring extensive communication between these organelles. One way by which organelles can communicate is through contact sites, areas of close apposition held together by tethering molecules. While many contacts have been characterized in yeast, the contact between the nucleus and mitochondria was not previously identified. Using fluorescence and electron microscopy in S. cerevisiae, we demonstrate specific areas of contact between the two organelles. Using a high-throughput screen, we uncover a role for the uncharacterized protein Ybr063c, which we have named Cnm1 (contact nucleus mitochondria 1), as a molecular tether on the nuclear membrane. We show that Cnm1 mediates contact by interacting with Tom70 on mitochondria. Moreover, Cnm1 abundance is regulated by phosphatidylcholine, enabling the coupling of phospholipid homeostasis with contact extent. The discovery of a molecular mechanism that allows mitochondrial crosstalk with the nucleus sets the ground for better understanding of mitochondrial functions in health and disease.
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Affiliation(s)
| | - Naama Zung
- Department of Molecular Genetics, Weizmann Institute of Science, Rehovot, Israel
| | - Javier Collado
- Institute for Neuropathology, Georg August Universität Göttingen, Göttingen, Germany.,Cluster of Excellence "Multiscale Bioimaging: from Molecular Machines to Networks of Excitable Cells," University of Göttingen, Göttingen, Germany
| | - Layla Drwesh
- Interfaculty Institute of Biochemistry, University of Tuebingen, Tuebingen, Germany
| | - Emma J Fenech
- Department of Molecular Genetics, Weizmann Institute of Science, Rehovot, Israel
| | - Amir Fadel
- Department of Molecular Genetics, Weizmann Institute of Science, Rehovot, Israel
| | - Nili Dezorella
- Electron Microscopy Unit, Chemical Research Support, Weizmann Institute of Science, Rehovot, Israel
| | - Yury S Bykov
- Department of Molecular Genetics, Weizmann Institute of Science, Rehovot, Israel
| | - Doron Rapaport
- Interfaculty Institute of Biochemistry, University of Tuebingen, Tuebingen, Germany
| | - Ruben Fernandez-Busnadiego
- Institute for Neuropathology, Georg August Universität Göttingen, Göttingen, Germany.,Cluster of Excellence "Multiscale Bioimaging: from Molecular Machines to Networks of Excitable Cells," University of Göttingen, Göttingen, Germany
| | - Maya Schuldiner
- Department of Molecular Genetics, Weizmann Institute of Science, Rehovot, Israel
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15
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Melatonin Attenuates Cardiac Ischemia-Reperfusion Injury through Modulation of IP3R-Mediated Mitochondria-ER Contact. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2021; 2021:1370862. [PMID: 34422206 PMCID: PMC8371645 DOI: 10.1155/2021/1370862] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/23/2021] [Revised: 07/17/2021] [Accepted: 07/24/2021] [Indexed: 02/07/2023]
Abstract
Although the interplay between mitochondria and ER has been identified as a crucial regulator of cellular homeostasis, the pathogenic impact of alterations in mitochondria-ER contact sites (MERCS) during myocardial postischemic reperfusion (I/R) injury remains incompletely understood. Therefore, in our study, we explored the beneficial role played by melatonin in protecting cardiomyocytes against reperfusion injury via stabilizing mitochondria-ER interaction. In vitro exposure of H9C2 rat cardiomyocytes to hypoxia/reoxygenation (H/R) augmented mitochondrial ROS synthesis, suppressed both mitochondrial potential and ATP generation, and increased the mitochondrial permeability transition pore (mPTP) opening rate. Furthermore, H/R exposure upregulated the protein content of CHOP and caspase-12, two markers of ER stress, and enhanced the transcription of main MERCS tethering proteins, namely, Fis1, BAP31, Mfn2, and IP3R. Interestingly, all the above changes could be attenuated or reversed by melatonin treatment. Suggesting that melatonin-induced cardioprotection works through normalization of mitochondria-ER interaction, overexpression of IP3R abolished the protective actions offered by melatonin on mitochondria-ER fitness. These results expand our knowledge on the cardioprotective actions of melatonin during myocardial postischemic reperfusion damage and suggest that novel, more effective treatments for acute myocardial reperfusion injury might be achieved through modulation of mitochondria-ER interaction in cardiac cells.
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16
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Transient Mitochondria Dysfunction Confers Fungal Cross-Resistance against Phagocytic Killing and Fluconazole. mBio 2021; 12:e0112821. [PMID: 34061590 PMCID: PMC8262853 DOI: 10.1128/mbio.01128-21] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
Loss or inactivation of antivirulence genes is an adaptive strategy in pathogen evolution. Candida glabrata is an important opportunistic pathogen related to baker’s yeast, with the ability to both quickly increase its intrinsic high level of azole resistance and persist within phagocytes. During C. glabrata’s evolution as a pathogen, the mitochondrial DNA polymerase CgMip1 has been under positive selection. We show that CgMIP1 deletion not only triggers loss of mitochondrial function and a petite phenotype, but increases C. glabrata’s azole and endoplasmic reticulum (ER) stress resistance and, importantly, its survival in phagocytes. The same phenotype is induced by fluconazole and by exposure to macrophages, conferring a cross-resistance between antifungals and immune cells, and can be found in clinical isolates despite a slow growth of petite strains. This suggests that petite constitutes a bet-hedging strategy of C. glabrata and, potentially, a relevant cause of azole resistance. Mitochondrial function may therefore be considered a potential antivirulence factor.
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17
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Yang M, Li C, Yang S, Xiao Y, Xiong X, Chen W, Zhao H, Zhang Q, Han Y, Sun L. Mitochondria-Associated ER Membranes - The Origin Site of Autophagy. Front Cell Dev Biol 2020; 8:595. [PMID: 32766245 PMCID: PMC7378804 DOI: 10.3389/fcell.2020.00595] [Citation(s) in RCA: 67] [Impact Index Per Article: 16.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2020] [Accepted: 06/18/2020] [Indexed: 12/21/2022] Open
Abstract
Autophagy is a process of intracellular self-recycling and degradation that plays an important role in maintaining cell homeostasis. However, the molecular mechanism of autophagy remains to be further studied. Mitochondria-associated endoplasmic reticulum membranes (MAMs) are the region of the ER that mediate communication between the ER and mitochondria. MAMs have been demonstrated to be involved in autophagy, Ca2+ transport and lipid metabolism. Here, we discuss the composition and function of MAMs, more specifically, to emphasize the role of MAMs in regulating autophagy. Finally, some key information that may be useful for future research is summarized.
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Affiliation(s)
- Ming Yang
- Hunan Key Laboratory of Kidney Disease and Blood Purification, Department of Nephrology, The Second Xiangya Hospital of Central South University, Changsha, China
| | - Chenrui Li
- Hunan Key Laboratory of Kidney Disease and Blood Purification, Department of Nephrology, The Second Xiangya Hospital of Central South University, Changsha, China
| | - Shikun Yang
- Department of Nephrology, The Third Xiangya Hospital of Central South University, Changsha, China
| | - Ying Xiao
- Hunan Key Laboratory of Kidney Disease and Blood Purification, Department of Nephrology, The Second Xiangya Hospital of Central South University, Changsha, China
| | - Xiaofen Xiong
- Hunan Key Laboratory of Kidney Disease and Blood Purification, Department of Nephrology, The Second Xiangya Hospital of Central South University, Changsha, China
| | - Wei Chen
- Hunan Key Laboratory of Kidney Disease and Blood Purification, Department of Nephrology, The Second Xiangya Hospital of Central South University, Changsha, China
| | - Hao Zhao
- Hunan Key Laboratory of Kidney Disease and Blood Purification, Department of Nephrology, The Second Xiangya Hospital of Central South University, Changsha, China
| | - Qin Zhang
- Hunan Key Laboratory of Kidney Disease and Blood Purification, Department of Nephrology, The Second Xiangya Hospital of Central South University, Changsha, China
| | - Yachun Han
- Hunan Key Laboratory of Kidney Disease and Blood Purification, Department of Nephrology, The Second Xiangya Hospital of Central South University, Changsha, China
| | - Lin Sun
- Hunan Key Laboratory of Kidney Disease and Blood Purification, Department of Nephrology, The Second Xiangya Hospital of Central South University, Changsha, China
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