Vacuole and mitochondria patch (vCLAMP) and ER-mitochondria encounter structure (ERMES) maintain cell survival by protecting mitochondrial functions in Candida albicans

AbstractMitochondrial proteases are key components in mitochondrial stress responses that maintain proteostasis and mitochondrial integrity in harsh environmental conditions, which leads to the acquisition of aggressive phenotypes, including chemoresistance and metastasis. However, the molecular mechanisms and exact role of mitochondrial proteases in cancer remain largely unexplored. Here, we identified functional crosstalk between LONP1 and ClpP, which are two mitochondrial matrix proteases that cooperate to attenuate proteotoxic stress and protect mitochondrial functions for cancer cell survival. LONP1 and ClpP genes closely localized on chromosome 19 and were co-expressed at high levels in most human cancers. Depletion of both genes synergistically attenuated cancer cell growth and induced cell death due to impaired mitochondrial functions and increased oxidative stress. Using mitochondrial matrix proteomic analysis with an engineered peroxidase (APEX)-mediated proximity biotinylation method, we identified the specific target substrates of these proteases, which were crucial components of mitochondrial functions, including oxidative phosphorylation, the TCA cycle, and amino acid and lipid metabolism. Furthermore, we found that LONP1 and ClpP shared many substrates, including serine hydroxymethyltransferase 2 (SHMT2). Inhibition of both LONP1 and ClpP additively increased the amount of unfolded SHMT2 protein and enhanced sensitivity to SHMT2 inhibitor, resulting in significantly reduced cell growth and increased cell death under metabolic stress. Additionally, prostate cancer patients with higher LONP1 and ClpP expression exhibited poorer survival. These results suggest that interventions targeting the mitochondrial proteostasis network via LONP1 and ClpP could be potential therapeutic strategies for cancer.

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The inositol polyphosphate kinase Ipk1 transcriptionally regulates mitochondrial functions in Candida albicans

FEMS Yeast Research ◽

10.1093/femsyr/foaa050 ◽

2020 ◽

Vol 20 (6) ◽

Author(s):

Hangqi Zhu ◽

Nali Zhu ◽

Liping Peng ◽

Bing Zhang ◽

Qilin Yu ◽

...

Keyword(s):

Candida Albicans ◽

Mitochondrial Function ◽

Antifungal Drugs ◽

Infection Model ◽

Polyphosphate Kinase ◽

Inositol Polyphosphate ◽

Human Beings ◽

Respiratory Chain Complexes ◽

Cellular Processes ◽

Mitochondrial Functions

ABSTRACT Inositol polyphosphates (IPs) is an important family of signaling molecules that regulate multiple cellular processes, such as chromatin remodeling, transcription and mRNA export. Inositol polyphosphate kinases, as the critical enzymes for production and transformation of IPs, directly determine the intracellular levels of IPs and therefore are involved in many cellular processes. However, its roles in Candida albicans, the leading fungal pathogen in human beings, remain to be investigated. In this study, we identified the inositol polyphosphate kinase Ipk1 in C. albicans and found that it localizes in the nucleus. Moreover, in the ipk1Δ/Δ mutant, the activity of mitochondrial respiratory chain complexes and the mitochondrial function was severely impaired, which were associated with down-regulation of mitochondrial function-related genes revealed by transcription profiling analysis. The ipk1Δ/Δ mutant also displayed hypersensitivity to a series of environmental stresses, such as antifungal drugs, oxidants, cell wall perturbing agents and macrophage attacks, followed by attenuation of virulence in a mouse systematic infection model. These findings firstly reported the importance of inositol polyphosphate kinase Ipk1 in C. albicans, especially its role in mitochondrial function maintenance and pathogenicity.

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The Vacuole and Mitochondria Patch (vCLAMP) Protein Mcp1 Is Involved in Maintenance of Mitochondrial Function and Mitophagy in Candida albicans

Frontiers in Microbiology ◽

10.3389/fmicb.2021.633380 ◽

2021 ◽

Vol 12 ◽

Author(s):

Xiaolong Mao ◽

Li Yang ◽

Yiming Fan ◽

Jiazhen Wang ◽

Dongkai Cui ◽

...

Keyword(s):

Candida Albicans ◽

Carbon Sources ◽

Cellular Functions ◽

Core Component ◽

Membrane Contact Sites ◽

Contact Sites ◽

Mitochondrial Functions ◽

Abnormal Accumulation ◽

Membrane Contact

The vacuole and mitochondria patches (vCLAMPs) are novel membrane contact sites in yeast. However, their role in autophagy has not been elucidated so far. In this article, the role of Mcp1, one core component of vCLAMP, in mitophagy of Candida albicans was investigated. Deletion of MCP1 led to abnormal accumulation of enlarged mitochondria and attenuated stability of mitochondrial DNA (mtDNA) in C. albicans when cultured in non-fermentable carbon sources. Furthermore, the mcp1Δ/Δ mutant exhibited defective growth and degradation of Csp37-GFP. These results indicate that Mcp1 plays a crucial role in mitophagy and maintenance of mitochondrial functions under the non-fermentable condition. Interestingly, this deletion had no impact on degradation of Atg8 (the macroautophagy reporter) and Lap41 (the cytoplasm-to-vacuole targeting pathway marker) under SD-N medium. Moreover, deletion of MCP1 inhibited filamentous growth and impaired virulence of the pathogen. This study provides an insight to vCLAMPs in cellular functions and pathogenicity in C. albicans.

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Impaired Regulation of Redox Transcriptome during the Differentiation of iPSCs into Induced Cardiomyocytes (iCMs)

10.1101/519793 ◽

2019 ◽

Author(s):

Gobinath Shanmugam ◽

David Crossman ◽

Johnson Rajasingh ◽

Brian Dalley ◽

Jianyi Zhang ◽

...

Keyword(s):

Cell Therapy ◽

Cell Survival ◽

Regulatory Networks ◽

Mitochondrial Dynamics ◽

Redox Signaling ◽

Transcriptional Networks ◽

Global Changes ◽

Myocardial Repair ◽

Mitochondrial Functions ◽

Global Transcriptome

AbstractBackgroundReprogramming of somatic cells into pluripotent stem cells (iPSC) and subsequent differentiation into iPSC-derived cardiomyocytes (iCM) seems to be a promising strategy for cardiac regenerative therapy. However, recent failure or poor outcomes in cardiac cell therapy warrants further investigation focusing on the infarction/wound environment (site of healing) to improve the cardiac regenerative medicine. Here, using next generation sequencing (NGS), we analyzed the global transcriptome to discover the unidentified genes/pathways that are crucial for cell survival, cytoprotection and mitochondrial dynamics during the differentiation of iPSC into iCM.MethodsHigh throughput NGS was performed RNA from human iPSCs and iCMs (n=3/group) and analyzed the global changes in the transcriptome during differentiation. Furthermore, Ingenuity Pathway Analysis (IPA) and Gene Ontology (GO) for biological process were performed to understand the transcriptional networks that are involved during iCM differentiation. RNA-seq data were further validated by qRT-PCR analyses.ResultsGlobal transcriptome analysis revealed that ~9,290 genes (log2 FC >2) were significantly altered in human iCMs compared to the parent iPSCs, in which 4,784 transcripts were substantially upregulated and 4,506 transcripts were down-regulated during differentiation. GO enrichment and IPA analyses revealed the top 10 regulatory networks (i.e. hierarchical order) involved in differentiation of iCMs including cardiomyocyte remodeling, integrin-linked kinase signaling, Rho family of GTPases, etc. Surprisingly, none of the top 10 pathways listed the genes liable for redox signaling networks that are crucial for the basal cellular redox homeostasis, Nrf2-dependent antioxidant defense, mitochondrial functions and cell survival. Our deeper and unbiased analysis of this data revealed that the genes involved in above canonical signaling pathways are found in the middle of the inverted vertical cone. Of note, although these pathways are significantly altered during the differentiation (of iPS into cardiomyocytes), a majority of them are ranked low in the hierarchical list (>150). Validation of the randomly selected genes representing various pathways real-time qPCR confirmed the global transcriptome changes observed in NGS.ConclusionWe highlight the significance of Nrf2-redox and mitochondrial transcriptome during differentiation of iPSC into iCMs. Thus, targeting the redox signaling mechanisms in iCMs may enhance their efficiency for cell therapy and improved myocardial repair.

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Mitochondrial Sorting and Assembly Machinery Subunit Sam37 in Candida albicans: Insight into the Roles of Mitochondria in Fitness, Cell Wall Integrity, and Virulence

Eukaryotic Cell ◽

10.1128/ec.05292-11 ◽

2012 ◽

Vol 11 (4) ◽

pp. 532-544 ◽

Cited By ~ 38

Author(s):

Yue Qu ◽

Branka Jelicic ◽

Filomena Pettolino ◽

Andrew Perry ◽

Tricia L. Lo ◽

...

Keyword(s):

Cell Wall ◽

Candida Albicans ◽

Mitochondrial Function ◽

Drug Tolerance ◽

Cell Wall Integrity ◽

Mitochondrial Outer Membrane ◽

Wall Structure ◽

Content Type ◽

Mitochondrial Functions ◽

Insight Into

ABSTRACT Recent studies indicate that mitochondrial functions impinge on cell wall integrity, drug tolerance, and virulence of human fungal pathogens. However, the mechanistic aspects of these processes are poorly understood. We focused on the mitochondrial outer membrane SAM ( S orting and A ssembly M achinery) complex subunit Sam37 in Candida albicans . Inactivation of SAM37 in C. albicans leads to a large reduction in fitness, a phenotype not conserved with the model yeast Saccharomyces cerevisiae . Our data indicate that slow growth of the sam37ΔΔ mutant results from mitochondrial DNA loss, a new function for Sam37 in C. albicans , and from reduced activity of the essential SAM complex subunit Sam35. The sam37ΔΔ mutant was hypersensitive to drugs that target the cell wall and displayed altered cell wall structure, supporting a role for Sam37 in cell wall integrity in C. albicans . The sensitivity of the mutant to membrane-targeting antifungals was not significantly altered. The sam37ΔΔ mutant was avirulent in the mouse model, and bioinformatics showed that the fungal Sam37 proteins are distant from their animal counterparts and could thus represent potential drug targets. Our study provides the first direct evidence for a link between mitochondrial function and cell wall integrity in C. albicans and is further relevant for understanding mitochondrial function in fitness, antifungal drug tolerance, and virulence of this major pathogen. Beyond the relevance to fungal pathogenesis, this work also provides new insight into the mitochondrial and cellular roles of the SAM complex in fungi.

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Methyl Jasmonate Cytotoxicity and Chemosensitization of T Cell Lymphoma In Vitro Is Facilitated by HK 2, HIF-1α, and Hsp70: Implication of Altered Regulation of Cell Survival, pH Homeostasis, Mitochondrial Functions

Frontiers in Pharmacology ◽

10.3389/fphar.2021.628329 ◽

2021 ◽

Vol 12 ◽

Author(s):

Yugal Goel ◽

Saveg Yadav ◽

Shrish Kumar Pandey ◽

Mithlesh Kumar Temre ◽

Vinay Kumar Singh ◽

...

Keyword(s):

T Cell ◽

Cell Survival ◽

Methyl Jasmonate ◽

Tumor Cells ◽

Molecular Mechanisms ◽

Cell Lymphoma ◽

T Cell Lymphoma ◽

Antitumor Action ◽

Ph Homeostasis ◽

Mitochondrial Functions

Methyl jasmonate (MJ) displays antineoplastic potential against numerous neoplastic cells. However, several mechanistic aspects of its antineoplastic action against malignancies of T cell origin remain elusive. The present investigation reports the novel targets of MJ and mechanistic pathways of MJ-mediated antineoplastic and chemosensitizing action against tumor cells derived from murine T-cell lymphoma, designated as Dalton’s lymphoma (DL). The present study demonstrates that MJ directly docks to HIF-1α, hexokinase 2, and Hsp70 at prominent binding sites. MJ exhibits tumoricidal action against tumor cells via induction of apoptosis and necrosis through multiple pathways, including declined mitochondrial membrane potential, enhanced expression of ROS, altered pH homeostasis, an elevated level of cytosolic cytochrome c, and modulated expression of crucial cell survival and metabolism regulatory molecules. Additionally, this study also reports the chemosensitizing ability of MJ against T cell lymphoma accompanied by a declined expression of MDR1. This study sheds new light by demonstrating the implication of novel molecular mechanisms underlying the antitumor action of MJ against T-cell lymphoma and hence has immense translational significance.

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Oxygen partial pressure plays a crucial role in B16 melanoma cell survival by regulating autophagy and mitochondrial functions

Biochemical and Biophysical Research Communications ◽

10.1016/j.bbrc.2019.01.135 ◽

2019 ◽

Vol 510 (4) ◽

pp. 643-648 ◽

Cited By ~ 1

Author(s):

Yuqing Wang ◽

Yan Wang ◽

Jia Wu ◽

Wei Wang ◽

Yu Zhang

Keyword(s):

Oxygen Partial Pressure ◽

Partial Pressure ◽

Cell Survival ◽

Melanoma Cell ◽

Crucial Role ◽

B16 Melanoma ◽

Mitochondrial Functions ◽

B16 Melanoma Cell ◽

And Mitochondrial Functions

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Scolopendin, an antimicrobial peptide from centipede, attenuates mitochondrial functions and triggers apoptosis in Candida albicans

Biochemical Journal ◽

10.1042/bcj20161039 ◽

2017 ◽

Vol 474 (5) ◽

pp. 635-645 ◽

Cited By ~ 20

Author(s):

Heejeong Lee ◽

Jae-Sam Hwang ◽

Dong Gun Lee

Keyword(s):

Cell Death ◽

Candida Albicans ◽

Antimicrobial Peptide ◽

Calcium Ion ◽

Chromatin Condensation ◽

Ion Homeostasis ◽

Ion Concentration ◽

Mitochondrial Functions ◽

Intracellular Changes ◽

Scolopendra Subspinipes Mutilans

Centipedes, a type of arthropod, reportedly produce antimicrobial peptides as part of an innate immune response. Scolopendin (SPSEKAGLQPVGRIGRMLKK) is a novel antimicrobial peptide derived from Scolopendra subspinipes mutilans. Many antifungal agents have more than one type of cell death mechanism. Although scolopendin is involved in membrane perturbation, the corresponding intracellular changes require further investigation. Therefore, we assessed the cell morphology and calcium ion concentration of the cytosol and mitochondria of scolopendin-treated cells. The treated cells were shrunken, and calcium ion homeostasis was disrupted in both the cytosol and mitochondria. These conditions attenuated mitochondrial homeostasis, disrupting mitochondrial membrane potential and cytochrome c levels. Fungal cells treated with scolopendin exhibited various apoptotic phenotypes such as reactive oxygen species accumulation, phosphatidylserine exposure, chromatin condensation, and nuclear fragmentation. Scolopendin-induced cell death also triggered metacaspase activation. In conclusion, treatment of Candida albicans with scolopendin induced the apoptotic response, which in turn led to mitochondrial dysfunction, metacaspase activation, and cell death. The antimicrobial peptide scolopendin from the centipede S.s. mutilans demonstrated a novel apoptotic mechanism as an antifungal agent.

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