1
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Omari S, Roded A, Eisenberg M, Ali H, Fukuda M, Galli SJ, Sagi-Eisenberg R. Mast cell secretory granule fusion with amphisomes coordinates their homotypic fusion and release of exosomes. Cell Rep 2024; 43:114482. [PMID: 38985670 DOI: 10.1016/j.celrep.2024.114482] [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: 01/31/2024] [Revised: 05/20/2024] [Accepted: 06/25/2024] [Indexed: 07/12/2024] Open
Abstract
Secretory granule (SG) fusion is an intermediate step in SG biogenesis. However, the precise mechanism of this process is not completely understood. We show that Golgi-derived mast cell (MC) SGs enlarge through a mechanism that is dependent on phosphoinositide (PI) remodeling and fusion with LC3+ late endosomes (amphisomes), which serve as hubs for the fusion of multiple individual SGs. Amphisome formation is regulated by the tyrosine phosphatase PTPN9, while the subsequent SG fusion event is additionally regulated by the tetraspanin protein CD63 and by PI4K. We also demonstrate that fusion with amphisomes imparts to SGs their capacity of regulated release of exosomes. Finally, we show that conversion of PI(3,4,5)P3 to PI(4,5)P2 and the subsequent recruitment of dynamin stimulate SG fission. Our data unveil a key role for lipid-regulated interactions with the endocytic and autophagic systems in controlling the size and number of SGs and their capacity to release exosomes.
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Affiliation(s)
- Sewar Omari
- Department of Cell and Developmental Biology, Faculty of Medical and Health Sciences, Tel Aviv University, Tel Aviv 69978, Israel
| | - Amit Roded
- Department of Cell and Developmental Biology, Faculty of Medical and Health Sciences, Tel Aviv University, Tel Aviv 69978, Israel
| | - Maggie Eisenberg
- Department of Cell and Developmental Biology, Faculty of Medical and Health Sciences, Tel Aviv University, Tel Aviv 69978, Israel
| | - Hydar Ali
- Department of Basic and Translational Sciences, School of Dental Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Mitsunori Fukuda
- Laboratory of Membrane Trafficking Mechanisms, Department of Integrative Life Sciences, Graduate School of Life Sciences, Tohoku University, Aobayama, Aoba-ku, Sendai, Miyagi 980-8578, Japan
| | - Stephen J Galli
- Departments of Pathology and of Microbiology and Immunology, and Sean N. Parker Center for Allergy and Asthma Research, Stanford University School of Medicine, Stanford, CA 94305-5176, USA
| | - Ronit Sagi-Eisenberg
- Department of Cell and Developmental Biology, Faculty of Medical and Health Sciences, Tel Aviv University, Tel Aviv 69978, Israel; Sagol School of Neuroscience, Tel Aviv University, Tel Aviv, Israel.
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2
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Song JZ, Feng YH, Sergevnina V, Zhu J, Li H, Xie Z. Assessing the Presence of Phosphoinositides on Autophagosomal Membrane in Yeast by Live Cell Imaging. Microorganisms 2024; 12:1458. [PMID: 39065227 PMCID: PMC11279164 DOI: 10.3390/microorganisms12071458] [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: 06/25/2024] [Revised: 07/14/2024] [Accepted: 07/15/2024] [Indexed: 07/28/2024] Open
Abstract
The formation of autophagosomes mediating the sequestration of cytoplasmic materials is the central step of autophagy. Several phosphoinositides, which are signaling molecules on the membrane, are involved in autophagy. However, it is not always clear whether these phosphoinositides act directly at the site of autophagosome formation, or indirectly via the regulation of other steps or pathways. To address this question, we used a set of phosphoinositide probes to systematically examine their potential presence on autophagosomal membranes in yeast (Saccharomyces cerevisiae). We verified the specificity of these probes using mutant cells deficient in the production of the corresponding phosphoinositides. We then examined starved yeast cells co-expressing a phosphoinositide probe together with an autophagosomal membrane marker, 2Katushka2S-Atg8. Our data revealed that PtdIns(4,5)P2 and PtdIns(3,5)P2 were mainly present on the plasma membrane and vacuolar membrane, respectively. We observed only occasional co-localization between the PtdIns(4)P probe and Atg8, some of which may represent the transient passage of a PtdIns(4)P-containing structure near the autophagosomal membrane. In contrast, substantial colocalization of the PtdIns(3)P probe with Atg8 was observed. Taken together, our data indicate that only PtdIns(3)P is present in a substantial amount on the autophagosomal membrane. For other phosphoinositides involved in autophagy, either their presence on the autophagosomal membrane is very transient, or they act on other cellular membranes to regulate autophagy.
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Affiliation(s)
| | | | | | | | - Hui Li
- State Key Laboratory of Microbial Metabolism, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Zhiping Xie
- State Key Laboratory of Microbial Metabolism, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai 200240, China
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3
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Wu YN, Lu JY, Li S, Zhang Y. Are vacuolar dynamics crucial factors for plant cell division and differentiation? PLANT SCIENCE : AN INTERNATIONAL JOURNAL OF EXPERIMENTAL PLANT BIOLOGY 2024; 344:112090. [PMID: 38636812 DOI: 10.1016/j.plantsci.2024.112090] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/14/2024] [Revised: 04/03/2024] [Accepted: 04/10/2024] [Indexed: 04/20/2024]
Abstract
Vacuoles are the largest membrane-bound organelles in plant cells, critical for development and environmental responses. Vacuolar dynamics indicate reversible changes of vacuoles in morphology, size, or numbers. In this review, we summarize current understandings of vacuolar dynamics in different types of plant cells, biological processes associated with vacuolar dynamics, and regulators controlling vacuolar dynamics. Specifically, we point out the possibility that vacuolar dynamics play key roles in cell division and differentiation, which are controlled by the nucleus. Finally, we propose three routes through which vacuolar dynamics actively participate in nucleus-controlled cellular activities.
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Affiliation(s)
- Ya-Nan Wu
- Frontiers Science Center for Cell Responses, College of Life Sciences, Nankai University, Tianjin 300071, China
| | - Jin-Yu Lu
- Frontiers Science Center for Cell Responses, College of Life Sciences, Nankai University, Tianjin 300071, China
| | - Sha Li
- College of Life Sciences, Shandong Agricultural University, Tai'an 271018, China
| | - Yan Zhang
- Frontiers Science Center for Cell Responses, College of Life Sciences, Nankai University, Tianjin 300071, China.
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4
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Lawrence SS, Kirschbaum C, Bennett JL, Lutomski CA, El-Baba TJ, Robinson CV. Phospholipids Differentially Regulate Ca 2+ Binding to Synaptotagmin-1. ACS Chem Biol 2024; 19:953-961. [PMID: 38566504 PMCID: PMC11040605 DOI: 10.1021/acschembio.3c00772] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2023] [Revised: 03/20/2024] [Accepted: 03/21/2024] [Indexed: 04/04/2024]
Abstract
Synaptotagmin-1 (Syt-1) is a calcium sensing protein that is resident in synaptic vesicles. It is well established that Syt-1 is essential for fast and synchronous neurotransmitter release. However, the role of Ca2+ and phospholipid binding in the function of Syt-1, and ultimately in neurotransmitter release, is unclear. Here, we investigate the binding of Ca2+ to Syt-1, first in the absence of lipids, using native mass spectrometry to evaluate individual binding affinities. Syt-1 binds to one Ca2+ with a KD ∼ 45 μM. Each subsequent binding affinity (n ≥ 2) is successively unfavorable. Given that Syt-1 has been reported to bind anionic phospholipids to modulate the Ca2+ binding affinity, we explored the extent that Ca2+ binding was mediated by selected anionic phospholipid binding. We found that phosphatidylinositol 4,5-bisphosphate (PI(4,5)P2) and dioleoylphosphatidylserine (DOPS) positively modulated Ca2+ binding. However, the extent of Syt-1 binding to phosphatidylinositol 3,5-bisphosphate (PI(3,5)P2) was reduced with increasing [Ca2+]. Overall, we find that specific lipids differentially modulate Ca2+ binding. Given that these lipids are enriched in different subcellular compartments and therefore may interact with Syt-1 at different stages of the synaptic vesicle cycle, we propose a regulatory mechanism involving Syt-1, Ca2+, and anionic phospholipids that may also control some aspects of vesicular exocytosis.
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Affiliation(s)
- Sophie
A. S. Lawrence
- Department
of Chemistry, University of Oxford, South Parks Road, Oxford OX1 3QZ, U.K.
- The
Kavli Institute for Nanoscience Discovery, University of Oxford, South Parks Road, Oxford OX1 3QU, U.K.
| | - Carla Kirschbaum
- Department
of Chemistry, University of Oxford, South Parks Road, Oxford OX1 3QZ, U.K.
- The
Kavli Institute for Nanoscience Discovery, University of Oxford, South Parks Road, Oxford OX1 3QU, U.K.
| | - Jack L. Bennett
- Department
of Chemistry, University of Oxford, South Parks Road, Oxford OX1 3QZ, U.K.
- The
Kavli Institute for Nanoscience Discovery, University of Oxford, South Parks Road, Oxford OX1 3QU, U.K.
| | - Corinne A. Lutomski
- Department
of Chemistry, University of Oxford, South Parks Road, Oxford OX1 3QZ, U.K.
- The
Kavli Institute for Nanoscience Discovery, University of Oxford, South Parks Road, Oxford OX1 3QU, U.K.
| | - Tarick J. El-Baba
- Department
of Chemistry, University of Oxford, South Parks Road, Oxford OX1 3QZ, U.K.
- The
Kavli Institute for Nanoscience Discovery, University of Oxford, South Parks Road, Oxford OX1 3QU, U.K.
| | - Carol. V. Robinson
- Department
of Chemistry, University of Oxford, South Parks Road, Oxford OX1 3QZ, U.K.
- The
Kavli Institute for Nanoscience Discovery, University of Oxford, South Parks Road, Oxford OX1 3QU, U.K.
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5
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Hayashida M, Nomura W, Shiojiri A, Inoue Y. Activation of the DNA damage checkpoint perturbs asymmetric localization of Kar9 to spindle pole bodies in Saccharomyces cerevisiae. Biochem Biophys Res Commun 2023; 685:149157. [PMID: 37918324 DOI: 10.1016/j.bbrc.2023.149157] [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: 10/15/2023] [Revised: 10/21/2023] [Accepted: 10/25/2023] [Indexed: 11/04/2023]
Abstract
During cell cycle progression in Saccharomyces cerevisiae, spindle pole bodies (SPBs) are duplicated during the G1/S-phase transition. SPBs are crucial for the organization of both the spindle and astral microtubules, and their orientation defines the direction of nuclear division. In this process, an old SPB, which serves as the template SPB during the duplication process, is oriented toward the bud side. The patterning microtubule plus-end tracking protein, Kar9, plays an important role in the orientation of SPBs by asymmetrically localizing to the old SPB. Here, methylglyoxal (MG), a metabolite derived from glycolysis, was found to perturb asymmetric Kar9 localization and influence proper positioning of the old SPB. MG activated the DNA damage checkpoint pathway, and MG-induced perturbation of asymmetric Kar9 localization was abolished by the deletion of MEC1, a sensor for the DNA damage checkpoint pathway. Methyl methanesulfonate, a DNA-alkylating agent, also perturbed asymmetric Kar9 localization. Our results suggest that activation of the DNA damage checkpoint pathway perturbs the asymmetric Kar9 localization required for proper positioning of SPBs.
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Affiliation(s)
- Momoko Hayashida
- Laboratory of Molecular Microbiology, Division of Applied Life Sciences, Graduate School of Agriculture, Kyoto University, Uji, Kyoto, 611-0011, Japan
| | - Wataru Nomura
- Laboratory of Molecular Microbiology, Division of Applied Life Sciences, Graduate School of Agriculture, Kyoto University, Uji, Kyoto, 611-0011, Japan; Research Unit for Physiological Chemistry, The Center for the Promotion of Interdisciplinary Education and Research, Kyoto University, Kyoto, 606-8501, Japan.
| | - Atsushi Shiojiri
- Laboratory of Molecular Microbiology, Division of Applied Life Sciences, Graduate School of Agriculture, Kyoto University, Uji, Kyoto, 611-0011, Japan
| | - Yoshiharu Inoue
- Laboratory of Molecular Microbiology, Division of Applied Life Sciences, Graduate School of Agriculture, Kyoto University, Uji, Kyoto, 611-0011, Japan.
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6
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Maeng KH, Lee H, Cho HT. FAB1C, a phosphatidylinositol 3-phosphate 5-kinase, interacts with PIN-FORMEDs and modulates their lytic trafficking in Arabidopsis. Proc Natl Acad Sci U S A 2023; 120:e2310126120. [PMID: 37934824 PMCID: PMC10655590 DOI: 10.1073/pnas.2310126120] [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: 06/15/2023] [Accepted: 10/10/2023] [Indexed: 11/09/2023] Open
Abstract
PIN-FORMEDs (PINs) are auxin efflux carriers that asymmetrically target the plasma membrane (PM) and are critical for forming local auxin gradients and auxin responses. While the cytoplasmic hydrophilic loop domain of PIN (PIN-HL) is known to include some molecular cues (e.g., phosphorylation) for the modulation of PIN's intracellular trafficking and activity, the complexity of auxin responses suggests that additional regulatory modules may operate in the PIN-HL domain. Here, we have identified and characterized a PIN-HL-interacting protein (PIP) called FORMATION OF APLOID AND BINUCLEATE CELL 1C (FAB1C), a phosphatidylinositol-3-phosphate 5-kinase, which modulates PIN's lytic trafficking. FAB1C directly interacts with PIN-HL and is required for the polarity establishment and vacuolar trafficking of PINs. Unphosphorylated forms of PIN2 interact more readily with FAB1C and are more susceptible to vacuolar lytic trafficking compared to phosphorylated forms. FAB1C also affected lateral root formation by modulating the abundance of periclinally localized PIN1 and auxin maximum in the growing lateral root primordium. These findings suggest that a membrane-lipid modifier can target the cargo-including vesicle by directly interacting with the cargo and modulate its trafficking depending on the cargo's phosphorylation status.
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Affiliation(s)
- Kwang-Ho Maeng
- Department of Biological Sciences, Seoul National University, Seoul08826, South Korea
| | - Hyodong Lee
- Department of Biological Sciences, Seoul National University, Seoul08826, South Korea
| | - Hyung-Taeg Cho
- Department of Biological Sciences, Seoul National University, Seoul08826, South Korea
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7
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Huda M, Bektas SN, Bekdas B, Caydasi AK. The signalling lipid PI3,5P 2 is essential for timely mitotic exit. Open Biol 2023; 13:230125. [PMID: 37751887 PMCID: PMC10522413 DOI: 10.1098/rsob.230125] [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: 05/02/2023] [Accepted: 08/15/2023] [Indexed: 09/28/2023] Open
Abstract
Coordination of mitotic exit with chromosome segregation is key for successful mitosis. Mitotic exit in budding yeast is executed by the mitotic exit network (MEN), which is negatively regulated by the spindle position checkpoint (SPOC). SPOC kinase Kin4 is crucial for SPOC activation in response to spindle positioning defects. Here, we report that the lysosomal signalling lipid phosphatidylinositol-3,5-bisphosphate (PI3,5P2) has an unanticipated role in the timely execution of mitotic exit. We show that the lack of PI3,5P2 causes a delay in mitotic exit, whereas elevated levels of PI3,5P2 accelerates mitotic exit in mitotic exit defective cells. Our data indicate that PI3,5P2 promotes mitotic exit in part through impairment of Kin4. This process is largely dependent on the known PI3,5P2 effector protein Atg18. Our work thus uncovers a novel link between PI3,5P2 and mitotic exit.
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Affiliation(s)
- Mariam Huda
- Department of Molecular Biology and Genetics, Koç University, Istanbul, Turkey
| | - Seyma Nur Bektas
- Department of Molecular Biology and Genetics, Koç University, Istanbul, Turkey
| | - Baris Bekdas
- Department of Molecular Biology and Genetics, Koç University, Istanbul, Turkey
| | - Ayse Koca Caydasi
- Department of Molecular Biology and Genetics, Koç University, Istanbul, Turkey
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8
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Tuli F, Kane PM. The cytosolic N-terminal domain of V-ATPase a-subunits is a regulatory hub targeted by multiple signals. Front Mol Biosci 2023; 10:1168680. [PMID: 37398550 PMCID: PMC10313074 DOI: 10.3389/fmolb.2023.1168680] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2023] [Accepted: 06/05/2023] [Indexed: 07/04/2023] Open
Abstract
Vacuolar H+-ATPases (V-ATPases) acidify several organelles in all eukaryotic cells and export protons across the plasma membrane in a subset of cell types. V-ATPases are multisubunit enzymes consisting of a peripheral subcomplex, V1, that is exposed to the cytosol and an integral membrane subcomplex, Vo, that contains the proton pore. The Vo a-subunit is the largest membrane subunit and consists of two domains. The N-terminal domain of the a-subunit (aNT) interacts with several V1 and Vo subunits and serves to bridge the V1 and Vo subcomplexes, while the C-terminal domain contains eight transmembrane helices, two of which are directly involved in proton transport. Although there can be multiple isoforms of several V-ATPase subunits, the a-subunit is encoded by the largest number of isoforms in most organisms. For example, the human genome encodes four a-subunit isoforms that exhibit a tissue- and organelle-specific distribution. In the yeast S. cerevisiae, the two a-subunit isoforms, Golgi-enriched Stv1 and vacuolar Vph1, are the only V-ATPase subunit isoforms. Current structural information indicates that a-subunit isoforms adopt a similar backbone structure but sequence variations allow for specific interactions during trafficking and in response to cellular signals. V-ATPases are subject to several types of environmental regulation that serve to tune their activity to their cellular location and environmental demands. The position of the aNT domain in the complex makes it an ideal target for modulating V1-Vo interactions and regulating enzyme activity. The yeast a-subunit isoforms have served as a paradigm for dissecting interactions of regulatory inputs with subunit isoforms. Importantly, structures of yeast V-ATPases containing each a-subunit isoform are available. Chimeric a-subunits combining elements of Stv1NT and Vph1NT have provided insights into how regulatory inputs can be integrated to allow V-ATPases to support cell growth under different stress conditions. Although the function and distribution of the four mammalian a-subunit isoforms present additional complexity, it is clear that the aNT domains of these isoforms are also subject to multiple regulatory interactions. Regulatory mechanisms that target mammalian a-subunit isoforms, and specifically the aNT domains, will be described. Altered V-ATPase function is associated with multiple diseases in humans. The possibility of regulating V-ATPase subpopulations via their isoform-specific regulatory interactions are discussed.
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Affiliation(s)
| | - Patricia M. Kane
- Department of Biochemistry and Molecular Biology, SUNY Upstate Medical University, Syracuse, NY, United States
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9
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Wang H, Zhang J, Liu H, Wang M, Dong Y, Zhou Y, Wong SM, Xu K, Xu Q. A plant virus hijacks phosphatidylinositol-3,5-bisphosphate to escape autophagic degradation in its insect vector. Autophagy 2023; 19:1128-1143. [PMID: 36093594 PMCID: PMC10012956 DOI: 10.1080/15548627.2022.2116676] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2021] [Revised: 06/29/2022] [Accepted: 08/20/2022] [Indexed: 02/07/2023] Open
Abstract
Hosts can initiate macroautophagy/autophagy as an antiviral defense response, while viruses have developed multiple ways to evade the host autophagic degradation. However, little is known as to whether viruses can target lipids to subvert autophagic degradation. Here, we show that a low abundant signaling lipid, phosphatidylinositol 3,5-bisphosphate (PtdIns(3,5)P2), is required for rice black-streaked dwarf virus (RBSDV) to evade the autophagic degradation in the insect vector Laodelphax striatellus. RBSDV binds to PtdIns(3,5)P2 and elevates its level through its main capsid protein P10, leading to inhibited autophagy and promoted virus propagation. Furthermore, we show that PtdIns(3,5)P2 inhibits the autophagy pathway by preventing the fusion of autophagosomes and lysosomes through activation of Trpml (transient receptor potential cation channel, mucolipin), an effector of PtdIns(3,5)P2. These findings uncover a strategy whereby a plant virus hijacks PtdIns(3,5)P2 via its viral capsid protein to evade autophagic degradation and promote its survival in insects.
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Affiliation(s)
- Haitao Wang
- Institute of Plant Protection, Key Lab of Food Quality and Safety of Jiangsu Province-State Key Laboratory Breeding Base, Jiangsu Academy of Agricultural Sciences, Nanjing, China
| | - Jianhua Zhang
- Institute of Plant Protection, Key Lab of Food Quality and Safety of Jiangsu Province-State Key Laboratory Breeding Base, Jiangsu Academy of Agricultural Sciences, Nanjing, China
- Institute of Industrial Crops, Shandong Academy of Agricultural Sciences, Jinan, China
| | - Haoqiu Liu
- Institute of Plant Protection, Key Lab of Food Quality and Safety of Jiangsu Province-State Key Laboratory Breeding Base, Jiangsu Academy of Agricultural Sciences, Nanjing, China
- Department of Biological Sciences, National University of Singapore, Singapore, Singapore
- National University of Singapore Research Institute, Suzhou, China
| | - Man Wang
- Institute of Plant Protection, Key Lab of Food Quality and Safety of Jiangsu Province-State Key Laboratory Breeding Base, Jiangsu Academy of Agricultural Sciences, Nanjing, China
| | - Yan Dong
- Institute of Plant Protection, Key Lab of Food Quality and Safety of Jiangsu Province-State Key Laboratory Breeding Base, Jiangsu Academy of Agricultural Sciences, Nanjing, China
| | - Yijun Zhou
- Institute of Plant Protection, Key Lab of Food Quality and Safety of Jiangsu Province-State Key Laboratory Breeding Base, Jiangsu Academy of Agricultural Sciences, Nanjing, China
| | - Sek-Man Wong
- Department of Biological Sciences, National University of Singapore, Singapore, Singapore
- National University of Singapore Research Institute, Suzhou, China
| | - Kai Xu
- Jiangsu Key Laboratory for Microbes and Functional Genomics, College of Life Sciences, Nanjing Normal University, Nanjing, China
| | - Qiufang Xu
- Institute of Plant Protection, Key Lab of Food Quality and Safety of Jiangsu Province-State Key Laboratory Breeding Base, Jiangsu Academy of Agricultural Sciences, Nanjing, China
- College of Life Sciences, Anhui Normal University, Wuhu, China
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10
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Qi L, Sun C, Sun S, Li A, Hu Q, Liu Y, Zhang Y. Phosphatidylinositol (3,5)-bisphosphate machinery regulates neurite thickness through neuron-specific endosomal protein NSG1/NEEP21. J Biol Chem 2022; 299:102775. [PMID: 36493904 PMCID: PMC9823133 DOI: 10.1016/j.jbc.2022.102775] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2022] [Revised: 10/31/2022] [Accepted: 11/29/2022] [Indexed: 12/12/2022] Open
Abstract
Phosphatidylinositol (3,5)-bisphosphate [PtdIns(3,5)P2] is a critical signaling phospholipid involved in endolysosome homeostasis. It is synthesized by a protein complex composed of PIKfyve, Vac14, and Fig4. Defects in PtdIns(3,5)P2 synthesis underlie a number of human neurological disorders, including Charcot-Marie-Tooth disease, child onset progressive dystonia, and others. However, neuron-specific functions of PtdIns(3,5)P2 remain less understood. Here, we show that PtdIns(3,5)P2 pathway is required to maintain neurite thickness. Suppression of PIKfyve activities using either pharmacological inhibitors or RNA silencing resulted in decreased neurite thickness. We further find that the regulation of neurite thickness by PtdIns(3,5)P2 is mediated by NSG1/NEEP21, a neuron-specific endosomal protein. Knockdown of NSG1 expression also led to thinner neurites. mCherry-tagged NSG1 colocalized and interacted with proteins in the PtdIns(3,5)P2 machinery. Perturbation of PtdIns(3,5)P2 dynamics by overexpressing Fig4 or a PtdIns(3,5)P2-binding domain resulted in mislocalization of NSG1 to nonendosomal locations, and suppressing PtdIns(3,5)P2 synthesis resulted in an accumulation of NSG1 in EEA1-positive early endosomes. Importantly, overexpression of NSG1 rescued neurite thinning in PtdIns(3,5)P2-deficient CAD neurons and primary cortical neurons. Our study uncovered the role of PtdIns(3,5)P2 in the morphogenesis of neurons, which revealed a novel aspect of the pathogenesis of PtdIns(3,5)P2-related neuropathies. We also identified NSG1 as an important downstream protein of PtdIns(3,5)P2, which may provide a novel therapeutic target in neurological diseases.
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Affiliation(s)
- Lijuan Qi
- Department of Biochemistry and Molecular Biology, Soochow University Medical College, Suzhou, Jiangsu, China,National Clinical Research Center for Hematologic Diseases, Jiangsu Institute of Hematology, The First Affiliated Hospital of Soochow University, Suzhou, Jiangsu, China
| | - Chen Sun
- Jiangsu Key Laboratory of Neuropsychiatric Diseases and Institute of Neuroscience, Clinical Research Center of Neurological Disease, The Second Affiliated Hospital of Soochow University, Soochow University, Suzhou, Jiangsu, China
| | - Shenqing Sun
- Department of Biochemistry and Molecular Biology, Soochow University Medical College, Suzhou, Jiangsu, China
| | - Aiqing Li
- Department of Biochemistry and Molecular Biology, Soochow University Medical College, Suzhou, Jiangsu, China
| | - Qiuming Hu
- Department of Biochemistry and Molecular Biology, Soochow University Medical College, Suzhou, Jiangsu, China
| | - Yaobo Liu
- Jiangsu Key Laboratory of Neuropsychiatric Diseases and Institute of Neuroscience, Clinical Research Center of Neurological Disease, The Second Affiliated Hospital of Soochow University, Soochow University, Suzhou, Jiangsu, China
| | - Yanling Zhang
- Department of Biochemistry and Molecular Biology, Soochow University Medical College, Suzhou, Jiangsu, China,For correspondence: Yanling Zhang
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11
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Patel S, Yuan Y, Chen CC, Jaślan D, Gunaratne G, Grimm C, Rahman T, Marchant JS. Electrophysiology of Endolysosomal Two-Pore Channels: A Current Account. Cells 2022; 11:2368. [PMID: 35954212 PMCID: PMC9368155 DOI: 10.3390/cells11152368] [Citation(s) in RCA: 6] [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: 05/30/2022] [Revised: 07/20/2022] [Accepted: 07/20/2022] [Indexed: 12/10/2022] Open
Abstract
Two-pore channels TPC1 and TPC2 are ubiquitously expressed pathophysiologically relevant proteins that reside on endolysosomal vesicles. Here, we review the electrophysiology of these channels. Direct macroscopic recordings of recombinant TPCs expressed in enlarged lysosomes in mammalian cells or vacuoles in plants and yeast demonstrate gating by the Ca2+-mobilizing messenger NAADP and/or the lipid PI(3,5)P2. TPC currents are regulated by H+, Ca2+, and Mg2+ (luminal and/or cytosolic), as well as protein kinases, and they are impacted by single-nucleotide polymorphisms linked to pigmentation. Bisbenzylisoquinoline alkaloids, flavonoids, and several approved drugs demonstrably block channel activity. Endogenous TPC currents have been recorded from a number of primary cell types and cell lines. Many of the properties of endolysosomal TPCs are recapitulated upon rerouting channels to the cell surface, allowing more facile recording through conventional electrophysiological means. Single-channel analyses have provided high-resolution insight into both monovalent and divalent permeability. The discovery of small-molecule activators of TPC2 that toggle the ion selectivity from a Ca2+-permeable (NAADP-like) state to a Na+-selective (PI(3,5)P2-like) state explains discrepancies in the literature relating to the permeability of TPCs. Identification of binding proteins that confer NAADP-sensitive currents confirm that indirect, remote gating likely underpins the inconsistent observations of channel activation by NAADP.
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Affiliation(s)
- Sandip Patel
- Department of Cell and Developmental Biology, University College London, London WC1E 6BT, UK;
| | - Yu Yuan
- Department of Cell and Developmental Biology, University College London, London WC1E 6BT, UK;
| | - Cheng-Chang Chen
- Department of Clinical Laboratory Sciences and Medical Biotechnology, College of Medicine, National Taiwan University, Taipei 100229, Taiwan;
- Department of Laboratory Medicine, National Taiwan University Hospital, Taipei 100225, Taiwan
| | - Dawid Jaślan
- Walther Straub Institute of Pharmacology and Toxicology, Faculty of Medicine, Ludwig-Maximilians University, 80336 Munich, Germany; (D.J.); (C.G.)
| | - Gihan Gunaratne
- Department of Cell Biology, Neurobiology and Anatomy, Medical College of Wisconsin, 8701 Watertown Plank Road, Milwaukee, WI 53226, USA; (G.G.); (J.S.M.)
| | - Christian Grimm
- Walther Straub Institute of Pharmacology and Toxicology, Faculty of Medicine, Ludwig-Maximilians University, 80336 Munich, Germany; (D.J.); (C.G.)
| | - Taufiq Rahman
- Department of Pharmacology, University of Cambridge, Cambridge CB2 1PD, UK;
| | - Jonathan S. Marchant
- Department of Cell Biology, Neurobiology and Anatomy, Medical College of Wisconsin, 8701 Watertown Plank Road, Milwaukee, WI 53226, USA; (G.G.); (J.S.M.)
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12
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Segregated cation flux by TPC2 biases Ca 2+ signaling through lysosomes. Nat Commun 2022; 13:4481. [PMID: 35918320 PMCID: PMC9346130 DOI: 10.1038/s41467-022-31959-0] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2022] [Accepted: 07/12/2022] [Indexed: 12/19/2022] Open
Abstract
Two-pore channels are endo-lysosomal cation channels with malleable selectivity filters that drive endocytic ion flux and membrane traffic. Here we show that TPC2 can differentially regulate its cation permeability when co-activated by its endogenous ligands, NAADP and PI(3,5)P2. Whereas NAADP rendered the channel Ca2+-permeable and PI(3,5)P2 rendered the channel Na+-selective, a combination of the two increased Ca2+ but not Na+ flux. Mechanistically, this was due to an increase in Ca2+ permeability independent of changes in ion selectivity. Functionally, we show that cell permeable NAADP and PI(3,5)P2 mimetics synergistically activate native TPC2 channels in live cells, globalizing cytosolic Ca2+ signals and regulating lysosomal pH and motility. Our data reveal that flux of different ions through the same pore can be independently controlled and identify TPC2 as a likely coincidence detector that optimizes lysosomal Ca2+ signaling. TPC2 is a lysosomal ion channel permeable to both calcium and sodium ions. Here, the authors show that TPC2 can selectively increase its calcium permeability when simultaneously challenged by both its natural activators- NAADP and PI(3,5)P2.
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13
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Kudo F, Eguchi T. Biosynthesis of cyclitols. Nat Prod Rep 2022; 39:1622-1642. [PMID: 35726901 DOI: 10.1039/d2np00024e] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Review covering up to 2021Cyclitols derived from carbohydrates are naturally stable hydrophilic substances under ordinary physiological conditions, increasing the water solubility of whole molecules in cells. The stability of cyclitols is derived from their carbocyclic structures bearing no acetal groups, in contrast to sugar molecules. Therefore, carbocycle-forming reactions are critical for the biosynthesis of cyclitols. Herein, we review naturally occurring cyclitols that have been identified to date and categorize them according to the type of carbocycle-forming enzymatic reaction. Furthermore, the cyclitol-forming enzymatic reaction mechanisms and modification pathways of the initially generated cyclitols are reviewed.
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Affiliation(s)
- Fumitaka Kudo
- Department of Chemistry, Tokyo Institute of Technology, 2-12-1 O-Okayama, Meguro-ku, Tokyo, Japan.
| | - Tadashi Eguchi
- Department of Chemistry, Tokyo Institute of Technology, 2-12-1 O-Okayama, Meguro-ku, Tokyo, Japan.
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14
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Leray X, Hilton JK, Nwangwu K, Becerril A, Mikusevic V, Fitzgerald G, Amin A, Weston MR, Mindell JA. Tonic inhibition of the chloride/proton antiporter ClC-7 by PI(3,5)P2 is crucial for lysosomal pH maintenance. eLife 2022; 11:74136. [PMID: 35670560 PMCID: PMC9242644 DOI: 10.7554/elife.74136] [Citation(s) in RCA: 23] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2021] [Accepted: 06/06/2022] [Indexed: 11/13/2022] Open
Abstract
The acidic luminal pH of lysosomes, maintained within a narrow range, is essential for proper degrative function of the organelle and is generated by the action of a V-type H+ ATPase, but other pathways for ion movement are required to dissipate the voltage generated by this process. ClC-7, a Cl-/H+ antiporter responsible for lysosomal Cl- permeability, is a candidate to contribute to the acidification process as part of this ‘counterion pathway’ The signaling lipid PI(3,5)P2 modulates lysosomal dynamics, including by regulating lysosomal ion channels, raising the possibility that it could contribute to lysosomal pH regulation. Here, we demonstrate that depleting PI(3,5)P2 by inhibiting the kinase PIKfyve causes lysosomal hyperacidification, primarily via an effect on ClC-7. We further show that PI(3,5)P2 directly inhibits ClC-7 transport and that this inhibition is eliminated in a disease-causing gain-of-function ClC-7 mutation. Together, these observations suggest an intimate role for ClC-7 in lysosomal pH regulation.
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Affiliation(s)
- Xavier Leray
- Membrane Transport Biophysics Section, National Institute of Neurological Disorders and Stroke
| | - Jacob K Hilton
- Membrane Transport Biophysics Section, National Institute of Neurological Disorders and Stroke
| | - Kamsi Nwangwu
- Membrane Transport Biophysics Section, National Institute of Neurological Disorders and Stroke
| | - Alissa Becerril
- Membrane Transport Biophysics Section, National Institute of Neurological Disorders and Stroke
| | - Vedrana Mikusevic
- Membrane Transport Biophysics Section, National Institute of Neurological Disorders and Stroke
| | - Gabriel Fitzgerald
- Membrane Transport Biophysics Section, National Institute of Neurological Disorders and Stroke
| | - Anowarul Amin
- Membrane Transport Biophysics Section, National Institute of Neurological Disorders and Stroke
| | - Mary R Weston
- Membrane Transport Biophysics Section, National Institute of Neurological Disorders and Stroke
| | - Joseph A Mindell
- Membrane Transport Biophysics Section, National Institute of Neurological Disorders and Stroke
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15
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Rivero-Ríos P, Weisman LS. Roles of PIKfyve in multiple cellular pathways. Curr Opin Cell Biol 2022; 76:102086. [PMID: 35584589 PMCID: PMC9108489 DOI: 10.1016/j.ceb.2022.102086] [Citation(s) in RCA: 39] [Impact Index Per Article: 19.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2022] [Revised: 03/27/2022] [Accepted: 04/02/2022] [Indexed: 02/01/2023]
Abstract
Phosphoinositide signaling lipids are crucial for eukaryotes and regulate many aspects of cell function. These signaling molecules are difficult to study because they are extremely low abundance. Here, we focus on two of the lowest abundance phosphoinositides, PI(3,5)P2 and PI(5)P, which play critical roles in cellular homeostasis, membrane trafficking and transcription. Their levels are tightly regulated by a protein complex that includes PIKfyve, Fig4 and Vac14. Importantly, mutations in this complex that decrease PI(3,5)P2 and PI(5)P are linked to human diseases, especially those of the nervous system. Paradoxically, PIKfyve inhibitors which decrease PI(3,5)P2 and PI(5)P, are currently being tested for some neurodegenerative diseases, as well as other diverse diseases including some cancers, and as a treatment for SARS-CoV2 infection. A more comprehensive picture of the pathways that are regulated by PIKfyve will be critical to understand the roles of PI(3,5)P2 and PI(5)P in normal human physiology and in disease.
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Affiliation(s)
- Pilar Rivero-Ríos
- Life Sciences Institute and Department of Cell and Developmental Biology, University of Michigan, Ann Arbor, MI, USA
| | - Lois S Weisman
- Life Sciences Institute and Department of Cell and Developmental Biology, University of Michigan, Ann Arbor, MI, USA.
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16
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Takuma T, Ushimaru T. Vacuolar fragmentation promotes fluxes of microautophagy and micronucleophagy but not of macroautophagy. Biochem Biophys Res Commun 2022; 614:161-168. [PMID: 35597153 DOI: 10.1016/j.bbrc.2022.05.021] [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: 04/18/2022] [Accepted: 05/07/2022] [Indexed: 11/17/2022]
Abstract
Vacuoles and lysosomes are organelles involved in the degradation of cytoplasmic proteins and organelles. Vacuolar morphology is dynamically regulated by fission and fusion in budding yeast. Vacuolar fusion is elicited in nutrient-depleted conditions and mediated by inactivation of target of rapamycin complex 1 (TORC1) protein kinase. However, it is unknown whether and how vacuolar morphology affects macroautophagy and microautophagy, which are induced by nutrient starvation and TORC1 inactivation. Here, we developed a system to control vacuolar fission in budding yeast. Vacuolar fragmentation promoted microautophagy but not macroautophagy. Vacuolar fragmentation caused multiple nucleus-vacuole junctions. Multiple vacuoles caused by vacuolar fragmentation also improved micronucleophagy (microautophagic degradation of a portion of the nucleus). However, vacuolar morphology did not impact nucleolar remodeling, condensation of the rDNA (rRNA gene) region, or separation of ribosomal DNA from nucleolar proteins, which is evoked by TORC1 inactivation. Thus, this study provides insights into the impacts of vacuolar/lysosomal morphology on macroautophagy and microautophagy.
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Affiliation(s)
- Tsuneyuki Takuma
- Graduate School of Science and Technology, Shizuoka University, Ohya 836, Suruga-ku, Shizuoka, 422-8021, Japan
| | - Takashi Ushimaru
- Graduate School of Science and Technology, Shizuoka University, Ohya 836, Suruga-ku, Shizuoka, 422-8021, Japan; Research Institute of Green Science and Technology, Shizuoka University, Ohya 836, Suruga-ku, Shizuoka, 422-8021, Japan.
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17
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Lie PPY, Yoo L, Goulbourne CN, Berg MJ, Stavrides P, Huo C, Lee JH, Nixon RA. Axonal transport of late endosomes and amphisomes is selectively modulated by local Ca 2+ efflux and disrupted by PSEN1 loss of function. SCIENCE ADVANCES 2022; 8:eabj5716. [PMID: 35486730 PMCID: PMC9054012 DOI: 10.1126/sciadv.abj5716] [Citation(s) in RCA: 24] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/11/2023]
Abstract
Dysfunction and mistrafficking of organelles in autophagy- and endosomal-lysosomal pathways are implicated in neurodegenerative diseases. Here, we reveal selective vulnerability of maturing degradative organelles (late endosomes/amphisomes) to disease-relevant local calcium dysregulation. These organelles undergo exclusive retrograde transport in axons, with occasional pauses triggered by regulated calcium efflux from agonist-evoked transient receptor potential cation channel mucolipin subfamily member 1 (TRPML1) channels-an effect greatly exaggerated by exogenous agonist mucolipin synthetic agonist 1 (ML-SA1). Deacidification of degradative organelles, as seen after Presenilin 1 (PSEN1) loss of function, induced pathological constitutive "inside-out" TRPML1 hyperactivation, slowing their transport comparably to ML-SA1 and causing accumulation in dystrophic axons. The mechanism involved calcium-mediated c-Jun N-terminal kinase (JNK) activation, which hyperphosphorylated dynein intermediate chain (DIC), reducing dynein activity. Blocking TRPML1 activation, JNK activity, or DIC1B serine-80 phosphorylation reversed transport deficits in PSEN1 knockout neurons. Our results, including features demonstrated in Alzheimer-mutant PSEN1 knockin mice, define a mechanism linking dysfunction and mistrafficking in lysosomal pathways to neuritic dystrophy under neurodegenerative conditions.
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Affiliation(s)
- Pearl P. Y. Lie
- Center for Dementia Research, Nathan S. Kline Institute, Orangeburg, NY 10962, USA
- Department of Psychiatry, New York University Langone Medical Center, New York, NY 10016, USA
| | - Lang Yoo
- Center for Dementia Research, Nathan S. Kline Institute, Orangeburg, NY 10962, USA
- Department of Psychiatry, New York University Langone Medical Center, New York, NY 10016, USA
| | - Chris N. Goulbourne
- Center for Dementia Research, Nathan S. Kline Institute, Orangeburg, NY 10962, USA
| | - Martin J. Berg
- Center for Dementia Research, Nathan S. Kline Institute, Orangeburg, NY 10962, USA
| | - Philip Stavrides
- Center for Dementia Research, Nathan S. Kline Institute, Orangeburg, NY 10962, USA
| | - Chunfeng Huo
- Center for Dementia Research, Nathan S. Kline Institute, Orangeburg, NY 10962, USA
| | - Ju-Hyun Lee
- Center for Dementia Research, Nathan S. Kline Institute, Orangeburg, NY 10962, USA
- Department of Psychiatry, New York University Langone Medical Center, New York, NY 10016, USA
| | - Ralph A. Nixon
- Center for Dementia Research, Nathan S. Kline Institute, Orangeburg, NY 10962, USA
- Department of Psychiatry, New York University Langone Medical Center, New York, NY 10016, USA
- Department of Cell Biology, New York University Langone Medical Center, New York, NY 10016, USA
- NYU Neuroscience Institute, New York University Langone Medical Center, New York, NY 10016, USA
- Corresponding author.
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18
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Hasegawa J, Tokuda E, Yao Y, Sasaki T, Inoki K, Weisman LS. PP2A-dependent TFEB activation is blocked by PIKfyve-induced mTORC1 activity. Mol Biol Cell 2022; 33:ar26. [PMID: 35020443 PMCID: PMC9250387 DOI: 10.1091/mbc.e21-06-0309] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Transcriptional factor EB (TFEB) is a master regulator of genes required for autophagy and lysosomal function. The nuclear localization of TFEB is blocked by the mechanistic target of rapamycin complex 1 (mTORC1)-dependent phosphorylation of TFEB at multiple sites including Ser-211. Here we show that inhibition of PIKfyve, which produces phosphatidylinositol 3,5-bisphosphate on endosomes and lysosomes, causes a loss of Ser-211 phosphorylation and concomitant nuclear localization of TFEB. We found that while mTORC1 activity toward S6K1, as well as other major mTORC1 substrates, is not impaired, PIKfyve inhibition specifically impedes the interaction of TFEB with mTORC1. This suggests that mTORC1 activity on TFEB is selectively inhibited due to loss of mTORC1 access to TFEB. In addition, we found that TFEB activation during inhibition of PIKfyve relies on the ability of protein phosphatase 2A (PP2A) but not calcineurin/PPP3 to dephosphorylate TFEB Ser-211. Thus when PIKfyve is inhibited, PP2A is dominant over mTORC1 for control of TFEB phosphorylation at Ser-S211. Together these findings suggest that mTORC1 and PP2A have opposing roles on TFEB via phosphorylation and dephosphorylation of Ser-211, respectively, and further that PIKfyve inhibits TFEB activity by facilitating mTORC1-dependent phosphorylation of TFEB.
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Affiliation(s)
- Junya Hasegawa
- Life Sciences Institute, University of Michigan, 210 Washtenaw Avenue, Ann Arbor, MI 48109, USA.,Department of Biochemical Pathophysiology, Medical Research Institute, Tokyo Medical and Dental University, 1-5-45, Yushima, Bunkyo-ku, Tokyo 113-8510, Japan
| | - Emi Tokuda
- Department of Biochemical Pathophysiology, Medical Research Institute, Tokyo Medical and Dental University, 1-5-45, Yushima, Bunkyo-ku, Tokyo 113-8510, Japan
| | - Yao Yao
- Life Sciences Institute, University of Michigan, 210 Washtenaw Avenue, Ann Arbor, MI 48109, USA
| | - Takehiko Sasaki
- Department of Biochemical Pathophysiology, Medical Research Institute, Tokyo Medical and Dental University, 1-5-45, Yushima, Bunkyo-ku, Tokyo 113-8510, Japan
| | - Ken Inoki
- Life Sciences Institute, University of Michigan, 210 Washtenaw Avenue, Ann Arbor, MI 48109, USA.,Department of Molecular and Integrative Physiology, University of Michigan Medical School, 1137 East Catherine Street, Ann Arbor, MI 48109, USA.,Department of Internal Medicine, University of Michigan Medical School, 1500 East Medical enter Drive, Ann Arbor, MI 48109, USA
| | - Lois S Weisman
- Life Sciences Institute, University of Michigan, 210 Washtenaw Avenue, Ann Arbor, MI 48109, USA.,Department of Cell and Developmental Biology, University of Michigan, 109 Zina Pitcher Place, Ann Arbor, MI 48109
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19
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Yu Y, Yin H, Ma C, Jia X, Chen W, Li H, Wu K. Case report and literature review: Novel compound heterozygous FIG4 variants causing both of peripheral and central nervous system defects. Front Pediatr 2022; 10:1008251. [PMID: 36340727 PMCID: PMC9634633 DOI: 10.3389/fped.2022.1008251] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/31/2022] [Accepted: 09/26/2022] [Indexed: 11/13/2022] Open
Abstract
BACKGROUND Pathogenic variants in the FIG4 gene have been described to be associated with a diverse spectrum of syndromes, such as autosomal recessive bilateral temporooccipital polymicrogyria (OMIM 612691), autosomal dominant amyotrophic lateral sclerosis-11 (ALS11; OMIM 612577), autosomal recessive Charcot-Marie-Tooth disease, type 4J (CMT4J; OMIM 611228), and autosomal recessive Yunis-Varon syndrome (YVS; OMIM 216340). Heterozygous FIG4 variants are responsible for ALS11 characterized by progressive muscular weakness, atrophy, and bulbar palsy. CMT4J is a disorder of peripheral nervous system defects mainly presenting with a highly variable onset of proximal and/or distal muscle weakness. YVS is a disorder of severe neurological involvement with central nervous system (CNS) dysfunction and extensive skeletal anomalies. CASE PRESENTATION We reported two Chinese siblings born with a weakness in all limbs. They experienced rapidly progressive weakness in distal limbs. At the age of 6 years, the elder brother presented with severe scoliosis and cervical kyphosis. They both had global developmental delay and a CNS involvement with cognitive deficits and swallowing problems. Genetic screening in the patients' family for inherited diseases was recommended. Novel compound heterozygous variants in the FIG4 gene (c.2148delTinsAA and c.317A > G) were found by whole-exome sequencing in the patients. These variants were confirmed by Sanger sequencing in family members. CONCLUSIONS Herein, we reported two Chinese male patients with CMT4J who presented with abnormal CNS features. CMT4J with CNS involvement has been very rarely reported. We hoped this study could expand the phenotypic and genetic spectrum of FIG4-related diseases. And we helped physicians to understand the genotype-phenotype correlation.
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Affiliation(s)
- Yonglin Yu
- Department of Rehabilitation, The Children's Hospital Zhejiang University School of Medicine, National Clinical Research Center for Child Health, Hangzhou, China
| | - Hongwei Yin
- Department of Rehabilitation, The Children's Hospital Zhejiang University School of Medicine, National Clinical Research Center for Child Health, Hangzhou, China
| | - Changli Ma
- Chigene (Beijing) Translational Medical Research Center Co Ltd, Beijing, China
| | - Xiaoyi Jia
- Department of Rehabilitation, The Children's Hospital Zhejiang University School of Medicine, National Clinical Research Center for Child Health, Hangzhou, China
| | - Wencong Chen
- Department of Rehabilitation, The Children's Hospital Zhejiang University School of Medicine, National Clinical Research Center for Child Health, Hangzhou, China
| | - Haifeng Li
- Department of Rehabilitation, The Children's Hospital Zhejiang University School of Medicine, National Clinical Research Center for Child Health, Hangzhou, China
| | - Ke Wu
- Chigene (Beijing) Translational Medical Research Center Co Ltd, Beijing, China.,Prenatal Diagnosis Center, Yiwu Maternity and Child Health Care Hospital, Yiwu, China
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20
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Ion Channels and Pumps in Autophagy: A Reciprocal Relationship. Cells 2021; 10:cells10123537. [PMID: 34944044 PMCID: PMC8700256 DOI: 10.3390/cells10123537] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2021] [Revised: 12/07/2021] [Accepted: 12/08/2021] [Indexed: 12/24/2022] Open
Abstract
Autophagy, the process of cellular self-degradation, is intrinsically tied to the degradative function of the lysosome. Several diseases have been linked to lysosomal degradative defects, including rare lysosomal storage disorders and neurodegenerative diseases. Ion channels and pumps play a major regulatory role in autophagy. Importantly, calcium signaling produced by TRPML1 (transient receptor potential cation channel, mucolipin subfamily) has been shown to regulate autophagic progression through biogenesis of autophagic-lysosomal organelles, activation of mTORC1 (mechanistic target of rapamycin complex 1) and degradation of autophagic cargo. ER calcium channels such as IP3Rs supply calcium for the lysosome, and lysosomal function is severely disrupted in the absence of lysosomal calcium replenishment by the ER. TRPML1 function is also regulated by LC3 (microtubule-associated protein light chain 3) and mTORC1, two critical components of the autophagic network. Here we provide an overview of the current knowledge about ion channels and pumps-including lysosomal V-ATPase (vacuolar proton-ATPase), which is required for acidification and hence proper enzymatic activity of lysosomal hydrolases-in the regulation of autophagy, and discuss how functional impairment of some of these leads to diseases.
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21
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Levine TP. TMEM106B in humans and Vac7 and Tag1 in yeast are predicted to be lipid transfer proteins. Proteins 2021; 90:164-175. [PMID: 34347309 DOI: 10.1002/prot.26201] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2021] [Revised: 07/11/2021] [Accepted: 07/23/2021] [Indexed: 11/05/2022]
Abstract
TMEM106B is an integral membrane protein of late endosomes and lysosomes involved in neuronal function, its overexpression being associated with familial frontotemporal lobar degeneration, and point mutation linked to hypomyelination. It has also been identified in multiple screens for host proteins required for productive SARS-CoV-2 infection. Because standard approaches to understand TMEM106B at the sequence level find no homology to other proteins, it has remained a protein of unknown function. Here, the standard tool PSI-BLAST was used in a nonstandard way to show that the lumenal portion of TMEM106B is a member of the late embryogenesis abundant-2 (LEA-2) domain superfamily. More sensitive tools (HMMER, HHpred, and trRosetta) extended this to predict LEA-2 domains in two yeast proteins. One is Vac7, a regulator of PI(3,5)P2 production in the degradative vacuole, equivalent to the lysosome, which has a LEA-2 domain in its lumenal domain. The other is Tag1, another vacuolar protein, which signals to terminate autophagy and has three LEA-2 domains in its lumenal domain. Further analysis of LEA-2 structures indicated that LEA-2 domains have a long, conserved lipid-binding groove. This implies that TMEM106B, Vac7, and Tag1 may all be lipid transfer proteins in the lumen of late endocytic organelles.
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22
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Bonilla DA, Moreno Y, Rawson ES, Forero DA, Stout JR, Kerksick CM, Roberts MD, Kreider RB. A Convergent Functional Genomics Analysis to Identify Biological Regulators Mediating Effects of Creatine Supplementation. Nutrients 2021; 13:2521. [PMID: 34444681 PMCID: PMC8397972 DOI: 10.3390/nu13082521] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2021] [Accepted: 07/21/2021] [Indexed: 12/12/2022] Open
Abstract
Creatine (Cr) and phosphocreatine (PCr) are physiologically essential molecules for life, given they serve as rapid and localized support of energy- and mechanical-dependent processes. This evolutionary advantage is based on the action of creatine kinase (CK) isozymes that connect places of ATP synthesis with sites of ATP consumption (the CK/PCr system). Supplementation with creatine monohydrate (CrM) can enhance this system, resulting in well-known ergogenic effects and potential health or therapeutic benefits. In spite of our vast knowledge about these molecules, no integrative analysis of molecular mechanisms under a systems biology approach has been performed to date; thus, we aimed to perform for the first time a convergent functional genomics analysis to identify biological regulators mediating the effects of Cr supplementation in health and disease. A total of 35 differentially expressed genes were analyzed. We identified top-ranked pathways and biological processes mediating the effects of Cr supplementation. The impact of CrM on miRNAs merits more research. We also cautiously suggest two dose-response functional pathways (kinase- and ubiquitin-driven) for the regulation of the Cr uptake. Our functional enrichment analysis, the knowledge-based pathway reconstruction, and the identification of hub nodes provide meaningful information for future studies. This work contributes to a better understanding of the well-reported benefits of Cr in sports and its potential in health and disease conditions, although further clinical research is needed to validate the proposed mechanisms.
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Affiliation(s)
- Diego A. Bonilla
- Research Division, Dynamical Business & Science Society—DBSS International SAS, Bogotá 110861, Colombia;
- Research Group in Biochemistry and Molecular Biology, Universidad Distrital Francisco José de Caldas, Bogotá 110311, Colombia
- Research Group in Physical Activity, Sports and Health Sciences (GICAFS), Universidad de Córdoba, Montería 230002, Colombia
- kDNA Genomics, Joxe Mari Korta Research Center, University of the Basque Country UPV/EHU, 20018 Donostia-San Sebastián, Spain
| | - Yurany Moreno
- Research Division, Dynamical Business & Science Society—DBSS International SAS, Bogotá 110861, Colombia;
- Research Group in Biochemistry and Molecular Biology, Universidad Distrital Francisco José de Caldas, Bogotá 110311, Colombia
| | - Eric S. Rawson
- Department of Health, Nutrition and Exercise Science, Messiah University, Mechanicsburg, PA 17055, USA;
| | - Diego A. Forero
- Professional Program in Sport Training, School of Health and Sport Sciences, Fundación Universitaria del Área Andina, Bogotá 111221, Colombia;
| | - Jeffrey R. Stout
- Physiology of Work and Exercise Response (POWER) Laboratory, Institute of Exercise Physiology and Rehabilitation Science, University of Central Florida, Orlando, FL 32816, USA;
| | - Chad M. Kerksick
- Exercise and Performance Nutrition Laboratory, School of Health Sciences, Lindenwood University, Saint Charles, MO 63301, USA;
| | - Michael D. Roberts
- School of Kinesiology, Auburn University, Auburn, AL 36849, USA;
- Edward via College of Osteopathic Medicine, Auburn, AL 36849, USA
| | - Richard B. Kreider
- Exercise & Sport Nutrition Laboratory, Human Clinical Research Facility, Texas A&M University, College Station, TX 77843, USA;
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23
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Mioka T, Guo T, Wang S, Tsuji T, Kishimoto T, Fujimoto T, Tanaka K. Characterization of micron-scale protein-depleted plasma membrane domains in phosphatidylserine-deficient yeast cells. J Cell Sci 2021; 135:261783. [PMID: 34000034 DOI: 10.1242/jcs.256529] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2020] [Accepted: 03/16/2021] [Indexed: 12/30/2022] Open
Abstract
Membrane phase separation to form micron-scale domains of lipids and proteins occurs in artificial membranes; however, a similar large-scale phase separation has not been reported in the plasma membrane of the living cells. We show here that a stable micron-scale protein-depleted region is generated in the plasma membrane of yeast mutants lacking phosphatidylserine at high temperatures. We named this region the 'void zone'. Transmembrane proteins and certain peripheral membrane proteins and phospholipids are excluded from the void zone. The void zone is rich in ergosterol, and requires ergosterol and sphingolipids for its formation. Such properties are also found in the cholesterol-enriched domains of phase-separated artificial membranes, but the void zone is a novel membrane domain that requires energy and various cellular functions for its formation. The formation of the void zone indicates that the plasma membrane in living cells has the potential to undergo phase separation with certain lipid compositions. We also found that void zones were frequently in contact with vacuoles, in which a membrane domain was also formed at the contact site.
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Affiliation(s)
- Tetsuo Mioka
- Division of Molecular Interaction, Institute for Genetic Medicine, Hokkaido University Graduate School of Life Science, Sapporo, Hokkaido 060-0815, Japan
| | - Tian Guo
- Division of Molecular Interaction, Institute for Genetic Medicine, Hokkaido University Graduate School of Life Science, Sapporo, Hokkaido 060-0815, Japan
| | - Shiyao Wang
- Division of Molecular Interaction, Institute for Genetic Medicine, Hokkaido University Graduate School of Life Science, Sapporo, Hokkaido 060-0815, Japan
| | - Takuma Tsuji
- Laboratory of Molecular Cell Biology, Research Institute for Diseases of Old Age, Juntendo University Graduate School of Medicine, Tokyo 113-8421, Japan
| | - Takuma Kishimoto
- Division of Molecular Interaction, Institute for Genetic Medicine, Hokkaido University Graduate School of Life Science, Sapporo, Hokkaido 060-0815, Japan
| | - Toyoshi Fujimoto
- Laboratory of Molecular Cell Biology, Research Institute for Diseases of Old Age, Juntendo University Graduate School of Medicine, Tokyo 113-8421, Japan
| | - Kazuma Tanaka
- Division of Molecular Interaction, Institute for Genetic Medicine, Hokkaido University Graduate School of Life Science, Sapporo, Hokkaido 060-0815, Japan
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Bao W, Wang X, Luo L, Ni R. The Lysosomal Storage Disorder Due to fig4a Mutation Causes Robust Liver Vacuolation in Zebrafish. Zebrafish 2021; 18:175-183. [PMID: 33909505 DOI: 10.1089/zeb.2020.1911] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
The phospholipid phosphatase FIG4/Fig4 is a subunit of PIKFYVE/Pikfyve kinase complex that synthesizes phosphatidylinositol 3,5-bisphosphate (PI(3,5)P2), a key regulator of endolysosomal trafficking and function. Loss of FIG4/Fig4 leads to intracellular deficiency of PI(3,5)P2 signaling and multiple endolysosomal defects. Previous works were focused on the effects of FIG4/Fig4 mutations in the nervous and musculoskeletal systems in human clinical and animal studies. In this study, we describe a zebrafish recessive mutant cq35 showing robust liver vacuolation and lethality, with a predicted truncating mutation in fig4a gene. The liver vacuolation progress in fig4a mutant was reversible after regaining normal fig4a transcripts. The hepatic vacuolation pathology was identified as abnormal lysosomal storage with numerous accumulated cargoes, including autophagy intermediates, and caused progressive degeneration of bile canaliculi in mutant liver. These hepatic pathological details of fig4a mutant were repeated in zebrafish pikfyve mutant. Thus, zebrafish possess the conserved structural and functional mechanisms in Pikfyve kinase complex, based on which, pikfyve mutant phenotype covered fig4a mutant phenotype in their double mutant. Our findings represent the first description of the in vivo defects caused by FIG4/Fig4 mutation or PI(3,5)P2 deficiency in liver, and reveal the conserved complex mechanisms associated with FIG4/Fig4-deficient disorders in zebrafish.
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Affiliation(s)
- Wandong Bao
- Key Laboratory of Freshwater Fish Reproduction and Development, Ministry of Education, Laboratory of Molecular Developmental Biology, School of Life Sciences, Southwest University, Chongqing, China
| | - Xinjuan Wang
- Key Laboratory of Freshwater Fish Reproduction and Development, Ministry of Education, Laboratory of Molecular Developmental Biology, School of Life Sciences, Southwest University, Chongqing, China
| | - Lingfei Luo
- Key Laboratory of Freshwater Fish Reproduction and Development, Ministry of Education, Laboratory of Molecular Developmental Biology, School of Life Sciences, Southwest University, Chongqing, China
| | - Rui Ni
- Key Laboratory of Freshwater Fish Reproduction and Development, Ministry of Education, Laboratory of Molecular Developmental Biology, School of Life Sciences, Southwest University, Chongqing, China
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Chadwick SR, Grinstein S, Freeman SA. From the inside out: Ion fluxes at the centre of endocytic traffic. Curr Opin Cell Biol 2021; 71:77-86. [PMID: 33706237 DOI: 10.1016/j.ceb.2021.02.006] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2020] [Revised: 01/19/2021] [Accepted: 02/04/2021] [Indexed: 12/15/2022]
Abstract
Endocytic traffic is a complex and elegant operation involving cargo sorting, membrane budding and tubulation, generation of force, and the formation of organellar contacts. The role of specific proteins and lipids in these processes has been studied extensively. By comparison, precious little is understood about the contribution of the endocytic fluid to these events, despite much evidence that alteration of the contents can severely affect membrane traffic along the endocytic pathway. In particular, it has long been appreciated that dissipation of ionic gradients arrests endosome-to-lysosome maturation. How cells sense inorganic ions and transmit this information have remained largely enigmatic. Herein, we review the experimental findings that reveal an intimate association between luminal ions, their transport, and endocytic traffic. We then discuss the ionic sensors and the mechanisms proposed to convert ion concentrations into protein-based trafficking events, highlighting the current paucity of convincing explanations.
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Affiliation(s)
- Sarah R Chadwick
- Program in Cell Biology, Peter Gilgan Centre for Research and Learning, Hospital for Sick Children, 686 Bay Street, 19-9800, Toronto, ON, M5G 0A4, Canada
| | - Sergio Grinstein
- Program in Cell Biology, Peter Gilgan Centre for Research and Learning, Hospital for Sick Children, 686 Bay Street, 19-9800, Toronto, ON, M5G 0A4, Canada; Department of Biochemistry, University of Toronto, Canada.
| | - Spencer A Freeman
- Program in Cell Biology, Peter Gilgan Centre for Research and Learning, Hospital for Sick Children, 686 Bay Street, 19-9800, Toronto, ON, M5G 0A4, Canada; Department of Biochemistry, University of Toronto, Canada.
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26
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Lees JA, Li P, Kumar N, Weisman LS, Reinisch KM. Insights into Lysosomal PI(3,5)P 2 Homeostasis from a Structural-Biochemical Analysis of the PIKfyve Lipid Kinase Complex. Mol Cell 2020; 80:736-743.e4. [PMID: 33098764 DOI: 10.1016/j.molcel.2020.10.003] [Citation(s) in RCA: 38] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2020] [Revised: 09/11/2020] [Accepted: 10/01/2020] [Indexed: 11/30/2022]
Abstract
The phosphoinositide PI(3,5)P2, generated exclusively by the PIKfyve lipid kinase complex, is key for lysosomal biology. Here, we explore how PI(3,5)P2 levels within cells are regulated. We find the PIKfyve complex comprises five copies of the scaffolding protein Vac14 and one copy each of the lipid kinase PIKfyve, generating PI(3,5)P2 from PI3P and the lipid phosphatase Fig4, reversing the reaction. Fig4 is active as a lipid phosphatase in the ternary complex, whereas PIKfyve within the complex cannot access membrane-incorporated phosphoinositides due to steric constraints. We find further that the phosphoinositide-directed activities of both PIKfyve and Fig4 are regulated by protein-directed activities within the complex. PIKfyve autophosphorylation represses its lipid kinase activity and stimulates Fig4 lipid phosphatase activity. Further, Fig4 is also a protein phosphatase acting on PIKfyve to stimulate its lipid kinase activity, explaining why catalytically active Fig4 is required for maximal PI(3,5)P2 production by PIKfyve in vivo.
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Affiliation(s)
- Joshua A Lees
- Department of Cell Biology, Yale School of Medicine, 333 Cedar Street, New Haven, CT 06520, USA
| | - PeiQi Li
- Department of Cell Biology, Yale School of Medicine, 333 Cedar Street, New Haven, CT 06520, USA
| | - Nikit Kumar
- Department of Cell Biology, Yale School of Medicine, 333 Cedar Street, New Haven, CT 06520, USA
| | - Lois S Weisman
- Life Sciences Institute, University of Michigan, Ann Arbor, MI 48109, USA
| | - Karin M Reinisch
- Department of Cell Biology, Yale School of Medicine, 333 Cedar Street, New Haven, CT 06520, USA.
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27
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Li S, Ghosh C, Xing Y, Sun Y. Phosphatidylinositol 4,5-bisphosphate in the Control of Membrane Trafficking. Int J Biol Sci 2020; 16:2761-2774. [PMID: 33061794 PMCID: PMC7545710 DOI: 10.7150/ijbs.49665] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2020] [Accepted: 08/14/2020] [Indexed: 12/15/2022] Open
Abstract
Phosphoinositides are membrane lipids generated by phosphorylation on the inositol head group of phosphatidylinositol. By specifically distributed to distinct subcellular membrane locations, different phosphoinositide species play diverse roles in modulating membrane trafficking. Among the seven known phosphoinositide species, phosphatidylinositol 4,5-bisphosphate (PI4,5P2) is the one species most abundant at the plasma membrane. Thus, the PI4,5P2 function in membrane trafficking is first identified in controlling plasma membrane dynamic-related events including endocytosis and exocytosis. However, recent studies indicate that PI4,5P2 is also critical in many other membrane trafficking events such as endosomal trafficking, hydrolases sorting to lysosomes, autophagy initiation, and autophagic lysosome reformation. These findings suggest that the role of PI4,5P2 in membrane trafficking is far beyond just plasma membrane. This review will provide a concise synopsis of how PI4,5P2 functions in multiple membrane trafficking events. PI4,5P2, the enzymes responsible for PI4,5P2 production at specific subcellular locations, and distinct PI4,5P2 effector proteins compose a regulation network to control the specific membrane trafficking events.
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Affiliation(s)
- Suhua Li
- Philips Institute for Oral Health Research, School of Dentistry and Massey Cancer Center, Virginia Commonwealth University, Richmond, VA 23298, USA
| | - Chinmoy Ghosh
- Philips Institute for Oral Health Research, School of Dentistry and Massey Cancer Center, Virginia Commonwealth University, Richmond, VA 23298, USA
| | - Yanli Xing
- Department of Otolaryngology, Shanghai Pudong New Area Gongli Hospital, Shanghai, China
| | - Yue Sun
- Philips Institute for Oral Health Research, School of Dentistry and Massey Cancer Center, Virginia Commonwealth University, Richmond, VA 23298, USA
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Molecular Basis for PI(3,5)P2 Recognition by SNX11, a Protein Involved in Lysosomal Degradation and Endosome Homeostasis Regulation. J Mol Biol 2020; 432:4750-4761. [DOI: 10.1016/j.jmb.2020.06.010] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2020] [Revised: 06/09/2020] [Accepted: 06/10/2020] [Indexed: 11/23/2022]
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Abstract
Autophagy degrades the cytoplasmic contents engulfed by autophagosomes. Besides providing energy and building blocks during starvation via random degradation, autophagy selectively targets cytotoxic components to prevent a wide range of diseases. This preventive activity of autophagy is supported by many studies using animal models and reports identifying several mutations in autophagy-related genes that are associated with human genetic disorders, which have been published in the past decade. Here, we summarize the molecular mechanisms of autophagosome biogenesis involving the proteins responsible for these genetic disorders, demonstrating a role for autophagy in human health. These findings will help elucidate the underlying mechanisms of autophagy-related diseases and develop future medications.
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Affiliation(s)
- Tsuyoshi Kawabata
- Department of Stem Cell Biology, Atomic Bomb Disease Institute, Nagasaki University, Nagasaki, 852-8523 Japan
| | - Tamotsu Yoshimori
- Department of Genetics, Graduate School of Medicine, Osaka University, Osaka, 565-0871 Japan
- Department of Intracellular Membrane Dynamics, Graduate School of Frontier Biosciences, Osaka University, Osaka, 565-0871 Japan
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Clement D, Goodridge JP, Grimm C, Patel S, Malmberg KJ. TRP Channels as Interior Designers: Remodeling the Endolysosomal Compartment in Natural Killer Cells. Front Immunol 2020; 11:753. [PMID: 32411146 PMCID: PMC7198808 DOI: 10.3389/fimmu.2020.00753] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2020] [Accepted: 04/02/2020] [Indexed: 12/15/2022] Open
Abstract
Cytotoxic lymphocytes, including natural killer (NK) cells and T cells are distinguished by their ability to eliminate target cells through release of secretory lysosomes. Conventional lysosomes and secretory lysosomes are part of the pleomorphic endolysosomal system and characterized by its highly dynamic nature. Several calcium-permeable TRP calcium channels play an essential role in endolysosomal calcium signaling to ensure proper function of these organelles. In NK cells, the expression of self MHC-specific inhibitory receptors dynamically tunes their secretory potential in a non-transcriptional, calcium-dependent manner. New insights suggest that TRPML1-mediated lysosomal calcium fluxes are tightly interconnected to NK cell functionality through modulation of granzyme B and perforin content of the secretory lysosome. Lysosomal TRP channels show a subset-specific expression pattern during NK differentiation, which is paralleled with gradually increased loading of effector molecules in secretory lysosomes. Methodological advances, including organellar patch-clamping, specific pharmacological modulators, and genetically-encoded calcium indicators open up new possibilities to investigate how TRP channels influence communication between intracellular organelles in immune cells. This review discusses our current understanding of lysosome biogenesis in NK cells with an emphasis on the TRP mucolipin family and the implications for NK cell functionality and cancer immunotherapy.
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Affiliation(s)
- Dennis Clement
- The KG Jebsen Center for Cancer Immunotherapy, Institute of Clinical Medicine, University of Oslo, Oslo, Norway
- Department of Cancer Immunology, Oslo University Hospital, Institute for Cancer Research, Oslo, Norway
| | | | - Christian Grimm
- Faculty of Medicine, Walther Straub Institute of Pharmacology and Toxicology, Ludwig-Maximilians-Universität, Munich, Germany
| | - Sandip Patel
- Department of Cell and Developmental Biology, University College London, London, United Kingdom
| | - Karl-Johan Malmberg
- The KG Jebsen Center for Cancer Immunotherapy, Institute of Clinical Medicine, University of Oslo, Oslo, Norway
- Department of Cancer Immunology, Oslo University Hospital, Institute for Cancer Research, Oslo, Norway
- Department of Medicine Huddinge, Center for Infectious Medicine, Karolinska Institutet, Stockholm, Sweden
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Calcium Dyshomeostasis and Lysosomal Ca 2+ Dysfunction in Amyotrophic Lateral Sclerosis. Cells 2019; 8:cells8101216. [PMID: 31597311 PMCID: PMC6829585 DOI: 10.3390/cells8101216] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2019] [Revised: 09/24/2019] [Accepted: 10/03/2019] [Indexed: 12/11/2022] Open
Abstract
Recent findings in the understanding of amyotrophic lateral sclerosis (ALS) revealed that alteration in calcium (Ca2+) homeostasis may largely contribute to motor neuron demise. A large part of these alterations is due to dysfunctional Ca2+-storing organelles, including the endoplasmic reticulum (ER) and mitochondria. Very recently, lysosomal Ca2+ dysfunction has emerged as an important pathological change leading to neuronal loss in ALS. Remarkably, the Ca2+-storing organelles are interacting with each other at specialized domains controlling mitochondrial dynamics, ER/lysosomal function, and autophagy. This occurs as a result of interaction between specific ionic channels and Ca2+-dependent proteins located in each structure. Therefore, the dysregulation of these ionic mechanisms could be considered as a key element in the neurodegenerative process. This review will focus on the possible role of lysosomal Ca2+ dysfunction in the pathogenesis of several neurodegenerative diseases, including ALS and shed light on the possibility that specific lysosomal Ca2+ channels might represent new promising targets for preventing or at least delaying neurodegeneration in ALS.
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32
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Gorzalczany Y, Merimsky O, Sagi-Eisenberg R. Mast Cells Are Directly Activated by Cancer Cell-Derived Extracellular Vesicles by a CD73- and Adenosine-Dependent Mechanism. Transl Oncol 2019; 12:1549-1556. [PMID: 31493676 PMCID: PMC6732751 DOI: 10.1016/j.tranon.2019.08.005] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2019] [Accepted: 08/05/2019] [Indexed: 12/20/2022] Open
Abstract
We have recently shown that mast cells (MCs), which constitute an important part of the tumor microenvironment (TME), can be directly activated by cancer cells under conditions that recapitulate cell to cell contact. However, MCs are often detected in the tumor periphery rather than intratumorally. Therefore, we investigated the possibility of MC activation by cancer cell–derived extracellular vesicles (EVs). Here we show that exposure of MCs to EVs derived from pancreatic cancer cells or non–small cell lung carcinoma results in MC activation, evident by the increased phosphorylation of the ERK1/2 MAP kinases. Further, we show that, similarly to activation by cancer cell contact, activation by EVs is dependent on the ecto enzyme CD73 that mediates extracellular formation of adenosine and on signaling by the A3 adenosine receptor. Finally, we show that activation by either cell contact or EVs upregulates expression of angiogenic and tissue remodeling genes, including IL8, IL6, VEGF, and amphiregulin. Collectively, our findings indicate that both intratumorally localized MCs and peripheral MCs are activated and reprogrammed in the TME either by contact with the cancer cells or by their released EVs.
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Affiliation(s)
- Yaara Gorzalczany
- Department of Cell and Developmental Biology, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, 69978, Israel
| | - Ofer Merimsky
- Unit of Soft Tissue and Bone Oncology, Division of Oncology, The Tel Aviv Sourasky Medical Center and Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, 69978, Israel
| | - Ronit Sagi-Eisenberg
- Department of Cell and Developmental Biology, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, 69978, Israel.
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33
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Yordanov TE, Hipolito VEB, Liebscher G, Vogel GF, Stasyk T, Herrmann C, Geley S, Teis D, Botelho RJ, Hess MW, Huber LA. Biogenesis of lysosome-related organelles complex-1 (BORC) regulates late endosomal/lysosomal size through PIKfyve-dependent phosphatidylinositol-3,5-bisphosphate. Traffic 2019; 20:674-696. [PMID: 31314175 PMCID: PMC6771566 DOI: 10.1111/tra.12679] [Citation(s) in RCA: 15] [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: 07/15/2019] [Accepted: 07/15/2019] [Indexed: 01/02/2023]
Abstract
Mechanisms that control lysosomal function are essential for cellular homeostasis. Lysosomes adapt in size and number to cellular needs but little is known about the underlying molecular mechanism. We demonstrate that the late endosomal/lysosomal multimeric BLOC-1-related complex (BORC) regulates the size of these organelles via PIKfyve-dependent phosphatidylinositol-3,5-bisphosphate [PI(3,5)P2 ] production. Deletion of the core BORC component Diaskedin led to increased levels of PI(3,5)P2 , suggesting activation of PIKfyve, and resulted in enhanced lysosomal reformation and subsequent reduction in lysosomal size. This process required AMP-activated protein kinase (AMPK), a known PIKfyve activator, and was additionally dependent on the late endosomal/lysosomal adaptor, mitogen-activated protein kinases and mechanistic target of rapamycin activator (LAMTOR/Ragulator) complex. Consistently, in response to glucose limitation, AMPK activated PIKfyve, which induced lysosomal reformation with increased baseline autophagy and was coupled to a decrease in lysosomal size. These adaptations of the late endosomal/lysosomal system reversed under glucose replete growth conditions. In summary, our results demonstrate that BORC regulates lysosomal reformation and size in response to glucose availability.
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Affiliation(s)
- Teodor E. Yordanov
- Division of Cell Biology, BiocenterMedical University of InnsbruckInnsbruckAustria
| | - Victoria E. B. Hipolito
- Department of Chemistry and Biology and the Graduate Program in Molecular ScienceRyerson UniversityTorontoOntarioCanada
| | - Gudrun Liebscher
- Division of Cell Biology, BiocenterMedical University of InnsbruckInnsbruckAustria
| | - Georg F. Vogel
- Division of Cell Biology, BiocenterMedical University of InnsbruckInnsbruckAustria
- Department of Pediatrics IMedical University of InnsbruckInnsbruckAustria
| | - Taras Stasyk
- Division of Cell Biology, BiocenterMedical University of InnsbruckInnsbruckAustria
| | - Caroline Herrmann
- Division of Cell Biology, BiocenterMedical University of InnsbruckInnsbruckAustria
| | - Stephan Geley
- Division of Molecular Pathophysiology, BiocenterMedical University of InnsbruckInnsbruckAustria
| | - David Teis
- Division of Cell Biology, BiocenterMedical University of InnsbruckInnsbruckAustria
| | - Roberto J. Botelho
- Department of Chemistry and Biology and the Graduate Program in Molecular ScienceRyerson UniversityTorontoOntarioCanada
| | - Michael W. Hess
- Division of Histology and EmbryologyMedical University of InnsbruckInnsbruckAustria
| | - Lukas A. Huber
- Division of Cell Biology, BiocenterMedical University of InnsbruckInnsbruckAustria
- Austrian Drug Screening Institute, ADSIInnsbruckAustria
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Nakada-Tsukui K, Watanabe N, Maehama T, Nozaki T. Phosphatidylinositol Kinases and Phosphatases in Entamoeba histolytica. Front Cell Infect Microbiol 2019; 9:150. [PMID: 31245297 PMCID: PMC6563779 DOI: 10.3389/fcimb.2019.00150] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2018] [Accepted: 04/23/2019] [Indexed: 12/11/2022] Open
Abstract
Phosphatidylinositol (PtdIns) metabolism is indispensable in eukaryotes. Phosphoinositides (PIs) are phosphorylated derivatives of PtdIns and consist of seven species generated by reversible phosphorylation of the inositol moieties at the positions 3, 4, and 5. Each of the seven PIs has a unique subcellular and membrane domain distribution. In the enteric protozoan parasite Entamoeba histolytica, it has been previously shown that the PIs phosphatidylinositol 3-phosphate (PtdIns3P), PtdIns(4,5)P2, and PtdIns(3,4,5)P3 are localized to phagosomes/phagocytic cups, plasma membrane, and phagocytic cups, respectively. The localization of these PIs in E. histolytica is similar to that in mammalian cells, suggesting that PIs have orthologous functions in E. histolytica. In contrast, the conservation of the enzymes that metabolize PIs in this organism has not been well-documented. In this review, we summarized the full repertoire of the PI kinases and PI phosphatases found in E. histolytica via a genome-wide survey of the current genomic information. E. histolytica appears to have 10 PI kinases and 23 PI phosphatases. It has a panel of evolutionarily conserved enzymes that generate all the seven PI species. However, class II PI 3-kinases, type II PI 4-kinases, type III PI 5-phosphatases, and PI 4P-specific phosphatases are not present. Additionally, regulatory subunits of class I PI 3-kinases and type III PI 4-kinases have not been identified. Instead, homologs of class I PI 3-kinases and PTEN, a PI 3-phosphatase, exist as multiple isoforms, which likely reflects that elaborate signaling cascades mediated by PtdIns(3,4,5)P3 are present in this organism. There are several enzymes that have the nuclear localization signal: one phosphatidylinositol phosphate (PIP) kinase, two PI 3-phosphatases, and one PI 5-phosphatase; this suggests that PI metabolism also has conserved roles related to nuclear functions in E. histolytica, as it does in model organisms.
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Affiliation(s)
- Kumiko Nakada-Tsukui
- Department of Parasitology, National Institute of Infectious Diseases, Tokyo, Japan
| | - Natsuki Watanabe
- Department of Parasitology, National Institute of Infectious Diseases, Tokyo, Japan.,Graduate School of Life and Environmental Sciences, University of Tsukuba, Tsukuba, Japan
| | - Tomohiko Maehama
- Division of Molecular and Cellular Biology, Graduate School of Medicine, Kobe University, Kobe, Japan
| | - Tomoyoshi Nozaki
- Department of Biomedical Chemistry, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan
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35
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Stamm CE, Pasko BL, Chaisavaneeyakorn S, Franco LH, Nair VR, Weigele BA, Alto NM, Shiloh MU. Screening Mycobacterium tuberculosis Secreted Proteins Identifies Mpt64 as a Eukaryotic Membrane-Binding Bacterial Effector. mSphere 2019; 4:e00354-19. [PMID: 31167949 PMCID: PMC6553557 DOI: 10.1128/msphere.00354-19] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2019] [Accepted: 05/19/2019] [Indexed: 02/07/2023] Open
Abstract
Mycobacterium tuberculosis (Mtb), the causative agent of tuberculosis, is one of the most successful human pathogens. One reason for its success is that Mtb can reside within host macrophages, a cell type that normally functions to phagocytose and destroy infectious bacteria. However, Mtb is able to evade macrophage defenses in order to survive for prolonged periods of time. Many intracellular pathogens secrete virulence factors targeting host membranes and organelles to remodel their intracellular environmental niche. We hypothesized that Mtb secreted proteins that target host membranes are vital for Mtb to adapt to and manipulate the host environment for survival. Thus, we characterized 200 secreted proteins from Mtb for their ability to associate with eukaryotic membranes using a unique temperature-sensitive yeast screen and to manipulate host trafficking pathways using a modified inducible secretion screen. We identified five Mtb secreted proteins that both associated with eukaryotic membranes and altered the host secretory pathway. One of these secreted proteins, Mpt64, localized to the endoplasmic reticulum during Mtb infection of murine and human macrophages and impaired the unfolded protein response in macrophages. These data highlight the importance of secreted proteins in Mtb pathogenesis and provide a basis for further investigation into their molecular mechanisms.IMPORTANCE Advances have been made to identify secreted proteins of Mycobacterium tuberculosis during animal infections. These data, combined with transposon screens identifying genes important for M. tuberculosis virulence, have generated a vast resource of potential M. tuberculosis virulence proteins. However, the function of many of these proteins in M. tuberculosis pathogenesis remains elusive. We have integrated three cell biological screens to characterize nearly 200 M. tuberculosis secreted proteins for eukaryotic membrane binding, host subcellular localization, and interactions with host vesicular trafficking. In addition, we observed the localization of one secreted protein, Mpt64, to the endoplasmic reticulum (ER) during M. tuberculosis infection of macrophages. Interestingly, although Mpt64 is exported by the Sec pathway, its delivery into host cells was dependent upon the action of the type VII secretion system. Finally, we observed that Mpt64 impairs the ER-mediated unfolded protein response in macrophages.
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Affiliation(s)
- Chelsea E Stamm
- Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, Texas, USA
- Department of Microbiology, University of Texas Southwestern Medical Center, Dallas, Texas, USA
| | - Breanna L Pasko
- Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, Texas, USA
- Department of Microbiology, University of Texas Southwestern Medical Center, Dallas, Texas, USA
| | - Sujittra Chaisavaneeyakorn
- Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, Texas, USA
- Department of Pediatrics, University of Texas Southwestern Medical Center, Dallas, Texas, USA
| | - Luis H Franco
- Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, Texas, USA
- Center for Autophagy Research, University of Texas Southwestern Medical Center, Dallas, Texas, USA
| | - Vidhya R Nair
- Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, Texas, USA
| | - Bethany A Weigele
- Department of Microbiology, University of Texas Southwestern Medical Center, Dallas, Texas, USA
| | - Neal M Alto
- Department of Microbiology, University of Texas Southwestern Medical Center, Dallas, Texas, USA
| | - Michael U Shiloh
- Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, Texas, USA
- Department of Microbiology, University of Texas Southwestern Medical Center, Dallas, Texas, USA
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36
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Saffi GT, Botelho RJ. Lysosome Fission: Planning for an Exit. Trends Cell Biol 2019; 29:635-646. [PMID: 31171420 DOI: 10.1016/j.tcb.2019.05.003] [Citation(s) in RCA: 67] [Impact Index Per Article: 13.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2019] [Revised: 05/01/2019] [Accepted: 05/03/2019] [Indexed: 01/26/2023]
Abstract
Lysosomes are acidic and degradative organelles that receive and digest a plethora of molecular and particulate cargo delivered by endocytosis, autophagy, and phagocytosis. The mechanisms responsible for sorting, transporting, and ultimately delivering membranes and cargo to lysosomes through fusion have been intensely investigated. Much less is understood about lysosome fission, which is necessary to balance the incessant flow of cargo into lysosomes and maintain steady-state number, size, and function of lysosomes. Here, we review the emerging picture of how lipid signals, coat and adaptor proteins, and motor-cytoskeletal assemblies drive budding, tubulation, splitting, and 'kiss-and-run' events that enable fission and exit from lysosomes and related organelles.
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Affiliation(s)
- Golam T Saffi
- Department of Chemistry and Biology and the Molecular Science Graduate Program, Ryerson University, Toronto, ONT, M5B2K3, Canada
| | - Roberto J Botelho
- Department of Chemistry and Biology and the Molecular Science Graduate Program, Ryerson University, Toronto, ONT, M5B2K3, Canada.
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37
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Banerjee S, Clapp K, Tarsio M, Kane PM. Interaction of the late endo-lysosomal lipid PI(3,5)P2 with the Vph1 isoform of yeast V-ATPase increases its activity and cellular stress tolerance. J Biol Chem 2019; 294:9161-9171. [PMID: 31023825 DOI: 10.1074/jbc.ra119.008552] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2019] [Revised: 04/22/2019] [Indexed: 12/30/2022] Open
Abstract
The low-level endo-lysosomal signaling lipid, phosphatidylinositol 3,5-bisphosphate (PI(3,5)P2), is required for full assembly and activity of vacuolar H+-ATPases (V-ATPases) containing the vacuolar a-subunit isoform Vph1 in yeast. The cytosolic N-terminal domain of Vph1 is also recruited to membranes in vivo in a PI(3,5)P2-dependent manner, but it is not known if its interaction with PI(3,5)P2 is direct. Here, using biochemical characterization of isolated yeast vacuolar vesicles, we demonstrate that addition of exogenous short-chain PI(3,5)P2 to Vph1-containing vacuolar vesicles activates V-ATPase activity and proton pumping. Modeling of the cytosolic N-terminal domain of Vph1 identified two membrane-oriented sequences that contain clustered basic amino acids. Substitutions in one of these sequences (231KTREYKHK) abolished the PI(3,5)P2-dependent activation of V-ATPase without affecting basal V-ATPase activity. We also observed that vph1 mutants lacking PI(3,5)P2 activation have enlarged vacuoles relative to those in WT cells. These mutants exhibit a significant synthetic growth defect when combined with deletion of Hog1, a kinase important for signaling the transcriptional response to osmotic stress. The results suggest that PI(3,5)P2 interacts directly with Vph1, and that this interaction both activates V-ATPase activity and protects cells from stress.
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Affiliation(s)
- Subhrajit Banerjee
- From the Department of Biochemistry and Molecular Biology, SUNY Upstate Medical University, Syracuse, New York 13210
| | - Kaitlyn Clapp
- From the Department of Biochemistry and Molecular Biology, SUNY Upstate Medical University, Syracuse, New York 13210
| | - Maureen Tarsio
- From the Department of Biochemistry and Molecular Biology, SUNY Upstate Medical University, Syracuse, New York 13210
| | - Patricia M Kane
- From the Department of Biochemistry and Molecular Biology, SUNY Upstate Medical University, Syracuse, New York 13210
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Fernandez-Mosquera L, Yambire KF, Couto R, Pereyra L, Pabis K, Ponsford AH, Diogo CV, Stagi M, Milosevic I, Raimundo N. Mitochondrial respiratory chain deficiency inhibits lysosomal hydrolysis. Autophagy 2019; 15:1572-1591. [PMID: 30917721 PMCID: PMC6693470 DOI: 10.1080/15548627.2019.1586256] [Citation(s) in RCA: 77] [Impact Index Per Article: 15.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
Mitochondria are key organelles for cellular metabolism, and regulate several processes including cell death and macroautophagy/autophagy. Here, we show that mitochondrial respiratory chain (RC) deficiency deactivates AMP-activated protein kinase (AMPK, a key regulator of energy homeostasis) signaling in tissue and in cultured cells. The deactivation of AMPK in RC-deficiency is due to increased expression of the AMPK-inhibiting protein FLCN (folliculin). AMPK is found to be necessary for basal lysosomal function, and AMPK deactivation in RC-deficiency inhibits lysosomal function by decreasing the activity of the lysosomal Ca2+ channel MCOLN1 (mucolipin 1). MCOLN1 is regulated by phosphoinositide kinase PIKFYVE and its product PtdIns(3,5)P2, which is also decreased in RC-deficiency. Notably, reactivation of AMPK, in a PIKFYVE-dependent manner, or of MCOLN1 in RC-deficient cells, restores lysosomal hydrolytic capacity. Building on these data and the literature, we propose that downregulation of the AMPK-PIKFYVE-PtdIns(3,5)P2-MCOLN1 pathway causes lysosomal Ca2+ accumulation and impaired lysosomal catabolism. Besides unveiling a novel role of AMPK in lysosomal function, this study points to the mechanism that links mitochondrial malfunction to impaired lysosomal catabolism, underscoring the importance of AMPK and the complexity of organelle cross-talk in the regulation of cellular homeostasis. Abbreviation: ΔΨm: mitochondrial transmembrane potential; AMP: adenosine monophosphate; AMPK: AMP-activated protein kinase; ATG5: autophagy related 5; ATP: adenosine triphosphate; ATP6V0A1: ATPase, H+ transporting, lysosomal, V0 subbunit A1; ATP6V1A: ATPase, H+ transporting, lysosomal, V0 subbunit A; BSA: bovine serum albumin; CCCP: carbonyl cyanide-m-chlorophenylhydrazone; CREB1: cAMP response element binding protein 1; CTSD: cathepsin D; CTSF: cathepsin F; DMEM: Dulbecco’s modified Eagle’s medium; DMSO: dimethyl sulfoxide; EBSS: Earl’s balanced salt solution; ER: endoplasmic reticulum; FBS: fetal bovine serum; FCCP: carbonyl cyanide-p-trifluoromethoxyphenolhydrazone; GFP: green fluorescent protein; GPN: glycyl-L-phenylalanine 2-naphthylamide; LAMP1: lysosomal associated membrane protein 1; MAP1LC3B/LC3B: microtubule associated protein 1 light chain 3 beta; MCOLN1/TRPML1: mucolipin 1; MEF: mouse embryonic fibroblast; MITF: melanocyte inducing transcription factor; ML1N*2-GFP: probe used to detect PtdIns(3,5)P2 based on the transmembrane domain of MCOLN1; MTORC1: mechanistic target of rapamycin kinase complex 1; NDUFS4: NADH:ubiquinone oxidoreductase subunit S4; OCR: oxygen consumption rate; PBS: phosphate-buffered saline; pcDNA: plasmid cytomegalovirus promoter DNA; PCR: polymerase chain reaction; PtdIns3P: phosphatidylinositol-3-phosphate; PtdIns(3,5)P2: phosphatidylinositol-3,5-bisphosphate; PIKFYVE: phosphoinositide kinase, FYVE-type zinc finger containing; P/S: penicillin-streptomycin; PVDF: polyvinylidene fluoride; qPCR: quantitative real time polymerase chain reaction; RFP: red fluorescent protein; RNA: ribonucleic acid; SDS-PAGE: sodium dodecyl sulfate polyacrylamide gel electrophoresis; shRNA: short hairpin RNA; siRNA: small interfering RNA; TFEB: transcription factor EB; TFE3: transcription factor binding to IGHM enhancer 3; TMRM: tetramethylrhodamine, methyl ester, perchlorate; ULK1: unc-51 like autophagy activating kinase 1; ULK2: unc-51 like autophagy activating kinase 2; UQCRC1: ubiquinol-cytochrome c reductase core protein 1; v-ATPase: vacuolar-type H+-translocating ATPase; WT: wild-type
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Affiliation(s)
- Lorena Fernandez-Mosquera
- a Institute of Cellular Biochemistry, University Medical Center Goettingen , Goettingen , Germany.,b Doctoral Program in Molecular Medicine, Georg August University Goettingen , Goettingen , Germany
| | - King Faisal Yambire
- a Institute of Cellular Biochemistry, University Medical Center Goettingen , Goettingen , Germany.,c International Max-Planck Research School in Neuroscience , Goettingen , Germany.,d European Neuroscience Institute Goettingen, University Medical Center Goettingen and Max-Planck Society , Goettingen , Germany
| | - Renata Couto
- a Institute of Cellular Biochemistry, University Medical Center Goettingen , Goettingen , Germany.,e Doctoral Program in Molecular Biology of Cells, Göttingen Graduate School for Neurosciences, Biophysics, and Molecular Biosciences, University of Goettingen , Goettingen , Germany
| | - Leonardo Pereyra
- a Institute of Cellular Biochemistry, University Medical Center Goettingen , Goettingen , Germany.,e Doctoral Program in Molecular Biology of Cells, Göttingen Graduate School for Neurosciences, Biophysics, and Molecular Biosciences, University of Goettingen , Goettingen , Germany
| | - Kamil Pabis
- a Institute of Cellular Biochemistry, University Medical Center Goettingen , Goettingen , Germany
| | - Amy H Ponsford
- f Institute of Translational Medicine, University of Liverpool , Liverpool , UK
| | - Cátia V Diogo
- a Institute of Cellular Biochemistry, University Medical Center Goettingen , Goettingen , Germany
| | - Massimiliano Stagi
- f Institute of Translational Medicine, University of Liverpool , Liverpool , UK
| | - Ira Milosevic
- d European Neuroscience Institute Goettingen, University Medical Center Goettingen and Max-Planck Society , Goettingen , Germany
| | - Nuno Raimundo
- a Institute of Cellular Biochemistry, University Medical Center Goettingen , Goettingen , Germany
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39
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Sharma S, Bhattacharya S, Bhattacharya A. PtdIns(4,5)P 2 is generated by a novel phosphatidylinositol 4-phosphate 5-kinase in the protist parasite Entamoeba histolytica. FEBS J 2019; 286:2216-2234. [PMID: 30843363 DOI: 10.1111/febs.14804] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2018] [Revised: 02/03/2019] [Accepted: 03/05/2019] [Indexed: 01/02/2023]
Abstract
Entamoeba histolytica is an intestinal protist parasite that causes amoebiasis, a major source of morbidity and mortality in developing countries. Phosphoinositides are involved in signalling systems that have a role in invasion and pathogenesis of this parasite. Phosphatidylinositol 4-phosphate 5-kinase (PIP5K) catalyses the generation of phosphatidylinositol(4,5)bisphosphate (PtdIns(4,5)P2 ), a key species of phosphoinositide that regulates various cellular processes. However, phosphatidylinositol phosphate kinase (PIPK) family of enzymes have not been characterized in E. histolytica. Here, we report the identification and characterization of type I PIPK (EhPIPKI) of E. histolytica. Computational analysis revealed homologs of type I and III PIPK family in E. histolytica and the absence of type II PIPK. In spite of low overall sequence identity, the kinase domain was found to be highly conserved. Interestingly, a unique insertion of a tandem repeat motif was observed in EhPIPKI distinguishing it from existing PIPKs of other organisms. Substrate profiling showed that EhPIPKI could phosphorylate at third and fifth hydroxyl positions of phosphatidylinositols, though the predominant substrate was phosphatidylinositol 4-phosphate (PtdIns(4)P). Furthermore, EhPIPKI underwent intracellular cleavage close to the amino-terminal, generating two distinct fragments Nter-EhPIPKI (27p) and Cter-EhPIPKI (47p). Immunofluorescence and cellular fractionation revealed that the full-length EhPIPKI and the Cter-EhPIPKI containing carboxyl-terminal activation loop were present in the plasma membrane while the Nter-EhPIPKI was observed in the cytosolic region. In conclusion, E. histolytica has a single EhPIPKI gene that displays novel properties of post-translational processing, the presence of a repeat domain and substrate specificity not observed in any PIPK enzyme so far.
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Affiliation(s)
- Shalini Sharma
- School of Life Sciences, Jawaharlal Nehru University, New Delhi, India
| | - Sudha Bhattacharya
- School of Environmental Sciences, Jawaharlal Nehru University, New Delhi, India
| | - Alok Bhattacharya
- School of Life Sciences, Jawaharlal Nehru University, New Delhi, India
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40
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Mironova YA, Lin JP, Kalinski AL, Huffman LD, Lenk GM, Havton LA, Meisler MH, Giger RJ. Protective role of the lipid phosphatase Fig4 in the adult nervous system. Hum Mol Genet 2019; 27:2443-2453. [PMID: 29688489 DOI: 10.1093/hmg/ddy145] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2018] [Accepted: 04/16/2018] [Indexed: 12/11/2022] Open
Abstract
The signaling lipid phosphatidylinositol 3,5-bisphosphate, PI(3,5)P2, functions in vesicular trafficking through the endo-lysosomal compartment. Cellular levels of PI(3,5)P2 are regulated by an enzyme complex comprised of the kinase PIKFYVE, the phosphatase FIG4, and the scaffold protein VAC14. Mutations of human FIG4 cause inherited disorders including Charcot-Marie-Tooth disease type 4J, polymicrogyria with epilepsy, and Yunis-Varón syndrome. Constitutive Fig4-/- mice exhibit intention tremor, spongiform degeneration of neural tissue, hypomyelination, and juvenile lethality. To determine whether PI(3,5)P2 is required in the adult, we generated Fig4flox/-; CAG-creER mice and carried out tamoxifen-induced gene ablation. Global ablation in adulthood leads to wasting, tremor, and motor impairment. Death follows within 2 months of tamoxifen treatment, demonstrating a life-long requirement for Fig4. Histological examinations of the sciatic nerve revealed profound Wallerian degeneration of myelinated fibers, but not C-fiber axons in Remak bundles. In optic nerve sections, myelinated fibers appear morphologically intact and carry compound action potentials at normal velocity and amplitude. However, when iKO mice are challenged with a chemical white matter lesion, repair of damaged CNS myelin is significantly delayed, demonstrating a novel role for Fig4 in remyelination. Thus, in the adult PNS Fig4 is required to protect myelinated axons from Wallerian degeneration. In the adult CNS, Fig4 is dispensable for fiber stability and nerve conduction, but is required for the timely repair of damaged white matter. The greater vulnerability of the PNS to Fig4 deficiency in the mouse is consistent with clinical observations in patients with Charcot-Marie-Tooth disease.
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Affiliation(s)
- Yevgeniya A Mironova
- Department of Cell and Developmental Biology, University of Michigan Medical School, Ann Arbor, MI, USA.,Cellular and Molecular Biology Graduate Program, University of Michigan Medical School, Ann Arbor, MI, USA
| | - Jing-Ping Lin
- Department of Cell and Developmental Biology, University of Michigan Medical School, Ann Arbor, MI, USA
| | - Ashley L Kalinski
- Department of Cell and Developmental Biology, University of Michigan Medical School, Ann Arbor, MI, USA
| | - Lucas D Huffman
- Department of Cell and Developmental Biology, University of Michigan Medical School, Ann Arbor, MI, USA.,Interdepartmental Neuroscience Graduate Program, University of Michigan Medical School, Ann Arbor, MI, USA
| | - Guy M Lenk
- Department of Human Genetics, University of Michigan Medical School, Ann Arbor, MI, USA
| | - Leif A Havton
- Department of Neurology, David Geffen School of Medicine at UCLA, Los Angeles, CA, USA
| | - Miriam H Meisler
- Interdepartmental Neuroscience Graduate Program, University of Michigan Medical School, Ann Arbor, MI, USA.,Department of Human Genetics, University of Michigan Medical School, Ann Arbor, MI, USA.,Department of Neurology, University of Michigan Medical School, Ann Arbor, MI, USA
| | - Roman J Giger
- Department of Cell and Developmental Biology, University of Michigan Medical School, Ann Arbor, MI, USA.,Cellular and Molecular Biology Graduate Program, University of Michigan Medical School, Ann Arbor, MI, USA.,Interdepartmental Neuroscience Graduate Program, University of Michigan Medical School, Ann Arbor, MI, USA.,Department of Neurology, University of Michigan Medical School, Ann Arbor, MI, USA
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41
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Sharma G, Guardia CM, Roy A, Vassilev A, Saric A, Griner LN, Marugan J, Ferrer M, Bonifacino JS, DePamphilis ML. A family of PIKFYVE inhibitors with therapeutic potential against autophagy-dependent cancer cells disrupt multiple events in lysosome homeostasis. Autophagy 2019; 15:1694-1718. [PMID: 30806145 DOI: 10.1080/15548627.2019.1586257] [Citation(s) in RCA: 76] [Impact Index Per Article: 15.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
High-throughput screening identified 5 chemical analogs (termed the WX8-family) that disrupted 3 events in lysosome homeostasis: (1) lysosome fission via tubulation without preventing homotypic lysosome fusion; (2) trafficking of molecules into lysosomes without altering lysosomal acidity, and (3) heterotypic fusion between lysosomes and autophagosomes. Remarkably, these compounds did not prevent homotypic fusion between lysosomes, despite the fact that homotypic fusion required some of the same machinery essential for heterotypic fusion. These effects varied 400-fold among WX8-family members, were time and concentration dependent, reversible, and resulted primarily from their ability to bind specifically to the PIKFYVE phosphoinositide kinase. The ability of the WX8-family to prevent lysosomes from participating in macroautophagy/autophagy suggested they have therapeutic potential in treating autophagy-dependent diseases. In fact, the most potent family member (WX8) was 100-times more lethal to 'autophagy-addicted' melanoma A375 cells than the lysosomal inhibitors hydroxychloroquine and chloroquine. In contrast, cells that were insensitive to hydroxychloroquine and chloroquine were also insensitive to WX8. Therefore, the WX8-family of PIKFYVE inhibitors provides a basis for developing drugs that could selectively kill autophagy-dependent cancer cells, as well as increasing the effectiveness of established anti-cancer therapies through combinatorial treatments. Abbreviations: ACTB: actin beta; Baf: bafilomycin A1; BECN1: beclin 1; BODIPY: boron-dipyrromethene; BORC: BLOC-1 related complex; BRAF: B-Raf proto-oncogene, serine/threonine kinase; BSA: bovine serum albumin; CTSD: cathepsin D; CQ: chloroquine; DNA: deoxyribonucleic acid; EC50: half maximal effective concentration; GAPDH: glyceraldehyde-3-phosphate dehydrogenase; GFP: green fluorescent protein; HCQ: hydroxychloroquine; HOPS complex: homotypic fusion and protein sorting complex; Kd: equilibrium binding constant; IC50: half maximal inhibitory concentration; KO: knockout; LAMP1: lysosomal associated membrane protein 1; MAP1LC3A: microtubule associated protein 1 light chain 3 alpha; MES: 2-(N-morpholino)ethanesulphonic acid; MTOR: mechanistic target of rapamycin kinase; μM: micromolar; NDF: 3-methylbenzaldehyde (2,6-dimorpholin-4-ylpyrimidin-4-yl)hydrazine;NEM: N-ethylmaleimide; NSF: N-ethylmaleimide sensitive factor; PBS: phosphate-buffered saline; PIKFYVE: phosphoinositide kinase, FYVE-type zinc finger containing; PIP4K2C: phosphatidylinositol-5-phosphate 4-kinase type 2 gamma; PtdIns3P: phosphatidylinositol 3-phosphate; PtdIns(3,5)P2: phosphatidylinositol 3,5-biphosphate; RFP: red fluorescent protein; RPS6: ribosomal protein S6; RPS6KB1: ribosomal protein S6 kinase B1; SQSTM1: sequestosome 1; TWEEN 20: polysorbate 20; V-ATPase: vacuolar-type H+-translocating ATPase; VPS39: VPS39 subunit of HOPS complex; VPS41: VPS41 subunit of HOPS complex; WWL: benzaldehyde [2,6-di(4-morpholinyl)-4-pyrimidinyl]hydrazone; WX8: 1H-indole-3-carbaldehyde [4-anilino-6-(4-morpholinyl)-1,3,5-triazin-2-yl]hydrazine; XBA: N-(3-chloro-4-fluorophenyl)-4,6-dimorpholino-1,3,5-triazin-2-amine hydrochloride; XB6: N-(4-ethylphenyl)-4,6-dimorpholino-1,3,5-triazin-2-amine hydrochloride.
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Affiliation(s)
- Gaurav Sharma
- Division of Developmental Biology, National Institute of Child Health & Human Development, National Institutes of Health , Bethesda , MD , USA
| | - Carlos M Guardia
- Cell Biology and Neurobiology Branch, National Institute of Child Health & Human Development, National Institutes of Health , Bethesda , MD , USA
| | - Ajit Roy
- Division of Developmental Biology, National Institute of Child Health & Human Development, National Institutes of Health , Bethesda , MD , USA
| | - Alex Vassilev
- Division of Developmental Biology, National Institute of Child Health & Human Development, National Institutes of Health , Bethesda , MD , USA
| | - Amra Saric
- Cell Biology and Neurobiology Branch, National Institute of Child Health & Human Development, National Institutes of Health , Bethesda , MD , USA
| | - Lori N Griner
- Division of Developmental Biology, National Institute of Child Health & Human Development, National Institutes of Health , Bethesda , MD , USA
| | - Juan Marugan
- Division of Pre-Clinical Innovation, NIH Chemical Genomics Center, National Center for Advancing Translational Sciences, National Institutes of Health , Rockville , MD , USA
| | - Marc Ferrer
- Division of Pre-Clinical Innovation, NIH Chemical Genomics Center, National Center for Advancing Translational Sciences, National Institutes of Health , Rockville , MD , USA
| | - Juan S Bonifacino
- Cell Biology and Neurobiology Branch, National Institute of Child Health & Human Development, National Institutes of Health , Bethesda , MD , USA
| | - Melvin L DePamphilis
- Division of Developmental Biology, National Institute of Child Health & Human Development, National Institutes of Health , Bethesda , MD , USA
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42
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Simonetti B, Cullen PJ. Actin-dependent endosomal receptor recycling. Curr Opin Cell Biol 2018; 56:22-33. [PMID: 30227382 DOI: 10.1016/j.ceb.2018.08.006] [Citation(s) in RCA: 62] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2018] [Revised: 08/20/2018] [Accepted: 08/27/2018] [Indexed: 12/18/2022]
Abstract
Endosomes constitute major sorting compartments within the cell. There, a myriad of transmembrane proteins (cargoes) are delivered to the lysosome for degradation or retrieved from this fate and recycled through tubulo-vesicular transport carriers to different cellular destinations. Retrieval and recycling are orchestrated by multi-protein assemblies that include retromer and retriever, sorting nexins, and the Arp2/3 activating WASH complex. Fine-tuned control of actin polymerization on endosomes is fundamental for the retrieval and recycling of cargoes. Recent advances in the field have highlighted several roles that actin plays in this process including the binding to cargoes, stabilization of endosomal subdomains, generation of the remodeling forces required for the biogenesis of cargo-enriched transport carriers and short-range motility of the transport carriers.
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Affiliation(s)
- Boris Simonetti
- School of Biochemistry, Biomedical Sciences Building, University of Bristol, Bristol BS8 1TD, UK
| | - Peter J Cullen
- School of Biochemistry, Biomedical Sciences Building, University of Bristol, Bristol BS8 1TD, UK.
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43
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Liggins MC, Flesher JL, Jahid S, Vasudeva P, Eby V, Takasuga S, Sasaki J, Sasaki T, Boissy RE, Ganesan AK. PIKfyve regulates melanosome biogenesis. PLoS Genet 2018; 14:e1007290. [PMID: 29584722 PMCID: PMC5889185 DOI: 10.1371/journal.pgen.1007290] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2017] [Revised: 04/06/2018] [Accepted: 03/05/2018] [Indexed: 12/18/2022] Open
Abstract
PIKfyve, VAC14, and FIG4 form a complex that catalyzes the production of PI(3,5)P2, a signaling lipid implicated in process ranging from lysosome maturation to neurodegeneration. While previous studies have identified VAC14 and FIG4 mutations that lead to both neurodegeneration and coat color defects, how PIKfyve regulates melanogenesis is unknown. In this study, we sought to better understand the role of PIKfyve in melanosome biogenesis. Melanocyte-specific PIKfyve knockout mice exhibit greying of the mouse coat and the accumulation of single membrane vesicle structures in melanocytes resembling multivesicular endosomes. PIKfyve inhibition blocks melanosome maturation, the processing of the melanosome protein PMEL, and the trafficking of the melanosome protein TYRP1. Taken together, these studies identify a novel role for PIKfyve in controlling the delivery of proteins from the endosomal compartment to the melanosome, a role that is distinct from the role of PIKfyve in the reformation of lysosomes from endolysosomes.
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Affiliation(s)
- Marc C. Liggins
- Department of Dermatology, University of California, San Diego, San Diego, CA, United States of America
| | - Jessica L. Flesher
- Department of Biological Chemistry, University of California, Irvine, Irvine, CA, United States of America
| | - Sohail Jahid
- Department of Dermatology, University of California, Irvine, Irvine, CA, United States of America
| | - Priya Vasudeva
- Department of Dermatology, University of California, Irvine, Irvine, CA, United States of America
| | - Victoria Eby
- Department of Dermatology, University of Cincinnati, Cincinnati, OH, United States of America
| | - Shunsuke Takasuga
- Department of Medical Biology, Akita University School of Medicine, Akita, Japan
| | - Junko Sasaki
- Department of Medical Biology, Akita University School of Medicine, Akita, Japan
| | - Takehiko Sasaki
- Department of Medical Biology, Akita University School of Medicine, Akita, Japan
| | - Raymond E. Boissy
- Department of Dermatology, University of Cincinnati, Cincinnati, OH, United States of America
| | - Anand K. Ganesan
- Department of Biological Chemistry, University of California, Irvine, Irvine, CA, United States of America
- Department of Dermatology, University of California, Irvine, Irvine, CA, United States of America
- * E-mail:
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44
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Narayanan P, Hütte M, Kudryasheva G, Taberner FJ, Lechner SG, Rehfeldt F, Gomez-Varela D, Schmidt M. Myotubularin related protein-2 and its phospholipid substrate PIP 2 control Piezo2-mediated mechanotransduction in peripheral sensory neurons. eLife 2018. [PMID: 29521261 PMCID: PMC5898911 DOI: 10.7554/elife.32346] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Piezo2 ion channels are critical determinants of the sense of light touch in vertebrates. Yet, their regulation is only incompletely understood. We recently identified myotubularin related protein-2 (Mtmr2), a phosphoinositide (PI) phosphatase, in the native Piezo2 interactome of murine dorsal root ganglia (DRG). Here, we demonstrate that Mtmr2 attenuates Piezo2-mediated rapidly adapting mechanically activated (RA-MA) currents. Interestingly, heterologous Piezo1 and other known MA current subtypes in DRG appeared largely unaffected by Mtmr2. Experiments with catalytically inactive Mtmr2, pharmacological blockers of PI(3,5)P2 synthesis, and osmotic stress suggest that Mtmr2-dependent Piezo2 inhibition involves depletion of PI(3,5)P2. Further, we identified a PI(3,5)P2 binding region in Piezo2, but not Piezo1, that confers sensitivity to Mtmr2 as indicated by functional analysis of a domain-swapped Piezo2 mutant. Altogether, our results propose local PI(3,5)P2 modulation via Mtmr2 in the vicinity of Piezo2 as a novel mechanism to dynamically control Piezo2-dependent mechanotransduction in peripheral sensory neurons. We often take our sense of touch for granted. Yet, our every-day life greatly depends on the ability to perceive our environment to alert us of danger or to further social interactions, such as mother-child bonding. Our sense of touch relies on the conversion of mechanical stimuli to electrical signals (this is known as mechanotransduction), which then travel to brain to be processed. This task is fulfilled by specific ion channels called Piezo2, which are activated when cells are exposed to pressure and other mechanical forces. These channels can be found in sensory nerves and specialized structures in the skin, where they help to detect physical contact, roughness of surfaces and the position of our body parts. It is still not clear how Piezo2 channels are regulated but previous research by several laboratories suggests that they work in conjunction with other proteins. One of these proteins is the myotubularin related protein-2, or Mtmr2 for short. Now, Narayanan et al. – including some of the researchers involved in the previous research – set out to advance our understanding of the molecular basis of touch and looked more closely at Mtmr2. To test if Mtmr2 played a role in mechanotransduction, Narayanan et al. both increased and reduced the levels of this protein in sensory neurons of mice grown in the laboratory. When Mtmr2 levels were low, the activity of Piezo2 channels increased. However, when the protein levels were high, Piezo2 channels were inhibited. These results suggest that Mtmr2 can control the activity of Piezo2. Further experiments, in which Mtmr2 was genetically modified or sensory neurons were treated with chemicals, revealed that Mtmr2 reduces a specific fatty acid in the membrane of nerve cells, which in turn attenuates the activity of Piezo2. This study identified Mtmr2 and distinct fatty acids in the cell membrane as new components of the complex setup required for the sense of touch. A next step will be to test if these molecules also influence the activity of Piezo2 when the skin has become injured or upon inflammation.
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Affiliation(s)
- Pratibha Narayanan
- Emmy Noether-Group Somatosensory Signaling and Systems Biology, Max Planck Institute for Experimental Medicine, Goettingen, Germany
| | - Meike Hütte
- Emmy Noether-Group Somatosensory Signaling and Systems Biology, Max Planck Institute for Experimental Medicine, Goettingen, Germany
| | - Galina Kudryasheva
- Third Institute of Physics - Biophysics, University of Goettingen, Goettingen, Germany
| | | | | | - Florian Rehfeldt
- Third Institute of Physics - Biophysics, University of Goettingen, Goettingen, Germany
| | - David Gomez-Varela
- Emmy Noether-Group Somatosensory Signaling and Systems Biology, Max Planck Institute for Experimental Medicine, Goettingen, Germany
| | - Manuela Schmidt
- Emmy Noether-Group Somatosensory Signaling and Systems Biology, Max Planck Institute for Experimental Medicine, Goettingen, Germany
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Deprez MA, Eskes E, Wilms T, Ludovico P, Winderickx J. pH homeostasis links the nutrient sensing PKA/TORC1/Sch9 ménage-à-trois to stress tolerance and longevity. MICROBIAL CELL 2018; 5:119-136. [PMID: 29487859 PMCID: PMC5826700 DOI: 10.15698/mic2018.03.618] [Citation(s) in RCA: 34] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
The plasma membrane H+-ATPase Pma1 and the vacuolar V-ATPase act in close harmony to tightly control pH homeostasis, which is essential for a vast number of physiological processes. As these main two regulators of pH are responsive to the nutritional status of the cell, it seems evident that pH homeostasis acts in conjunction with nutrient-induced signalling pathways. Indeed, both PKA and the TORC1-Sch9 axis influence the proton pumping activity of the V-ATPase and possibly also of Pma1. In addition, it recently became clear that the proton acts as a second messenger to signal glucose availability via the V-ATPase to PKA and TORC1-Sch9. Given the prominent role of nutrient signalling in longevity, it is not surprising that pH homeostasis has been linked to ageing and longevity as well. A first indication is provided by acetic acid, whose uptake by the cell induces toxicity and affects longevity. Secondly, vacuolar acidity has been linked to autophagic processes, including mitophagy. In agreement with this, a decline in vacuolar acidity was shown to induce mitochondrial dysfunction and shorten lifespan. In addition, the asymmetric inheritance of Pma1 has been associated with replicative ageing and this again links to repercussions on vacuolar pH. Taken together, accumulating evidence indicates that pH homeostasis plays a prominent role in the determination of ageing and longevity, thereby providing new perspectives and avenues to explore the underlying molecular mechanisms.
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Affiliation(s)
| | - Elja Eskes
- Functional Biology, KU Leuven, Leuven, Belgium
| | | | - Paula Ludovico
- Life and Health Sciences Research Institute (ICVS), School of Medicine, University of Minho, Braga, Portugal; ICVS/3B's - PT Government Associate Laboratory, Braga/Guimarães, Portugal
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Spiliotis ET. Spatial effects - site-specific regulation of actin and microtubule organization by septin GTPases. J Cell Sci 2018; 131:jcs207555. [PMID: 29326311 PMCID: PMC5818061 DOI: 10.1242/jcs.207555] [Citation(s) in RCA: 79] [Impact Index Per Article: 13.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
The actin and microtubule cytoskeletons comprise a variety of networks with distinct architectures, dynamics and protein composition. A fundamental question in eukaryotic cell biology is how these networks are spatially and temporally controlled, so they are positioned in the right intracellular places at the right time. While significant progress has been made in understanding the self-assembly of actin and microtubule networks, less is known about how they are patterned and regulated in a site-specific manner. In mammalian systems, septins are a large family of GTP-binding proteins that multimerize into higher-order structures, which associate with distinct subsets of actin filaments and microtubules, as well as membranes of specific curvature and lipid composition. Recent studies have shed more light on how septins interact with actin and microtubules, and raised the possibility that the cytoskeletal topology of septins is determined by their membrane specificity. Importantly, new functions have emerged for septins regarding the generation, maintenance and positioning of cytoskeletal networks with distinct organization and biochemical makeup. This Review presents new and past findings, and discusses septins as a unique regulatory module that instructs the local differentiation and positioning of distinct actin and microtubule networks.
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Affiliation(s)
- Elias T Spiliotis
- Drexel University, Department of Biology, Drexel University, Philadelphia, PA 19104, USA
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Hesketh GG, Wartosch L, Davis LJ, Bright NA, Luzio JP. The Lysosome and Intracellular Signalling. PROGRESS IN MOLECULAR AND SUBCELLULAR BIOLOGY 2018; 57:151-180. [PMID: 30097775 DOI: 10.1007/978-3-319-96704-2_6] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
In addition to being the terminal degradative compartment of the cell's endocytic and autophagic pathways, the lysosome is a multifunctional signalling hub integrating the cell's response to nutrient status and growth factor/hormone signalling. The cytosolic surface of the limiting membrane of the lysosome is the site of activation of the multiprotein complex mammalian target of rapamycin complex 1 (mTORC1), which phosphorylates numerous cell growth-related substrates, including transcription factor EB (TFEB). Under conditions in which mTORC1 is inhibited including starvation, TFEB becomes dephosphorylated and translocates to the nucleus where it functions as a master regulator of lysosome biogenesis. The signalling role of lysosomes is not limited to this pathway. They act as an intracellular Ca2+ store, which can release Ca2+ into the cytosol for both local effects on membrane fusion and pleiotropic effects within the cell. The relationship and crosstalk between the lysosomal and endoplasmic reticulum (ER) Ca2+ stores play a role in shaping intracellular Ca2+ signalling. Lysosomes also perform other signalling functions, which are discussed. Current views of the lysosomal compartment recognize its dynamic nature. It includes endolysosomes, autolysosome and storage lysosomes that are constantly engaged in fusion/fission events and lysosome regeneration. How signalling is affected by individual lysosomal organelles being at different stages of these processes and/or at different sites within the cell is poorly understood, but is discussed.
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Affiliation(s)
- Geoffrey G Hesketh
- Lunenfeld-Tanenbaum Research Institute, Sinai Health System, Toronto, ON, M5G 1X5, Canada
| | - Lena Wartosch
- Department of Clinical Biochemistry and Cambridge Institute for Medical Research, School of Clinical Medicine, Wellcome Trust/MRC Building, University of Cambridge, Cambridge Biomedical Campus, Hills Road, Cambridge, CB2 0XY, UK
| | - Luther J Davis
- Department of Clinical Biochemistry and Cambridge Institute for Medical Research, School of Clinical Medicine, Wellcome Trust/MRC Building, University of Cambridge, Cambridge Biomedical Campus, Hills Road, Cambridge, CB2 0XY, UK
| | - Nicholas A Bright
- Department of Clinical Biochemistry and Cambridge Institute for Medical Research, School of Clinical Medicine, Wellcome Trust/MRC Building, University of Cambridge, Cambridge Biomedical Campus, Hills Road, Cambridge, CB2 0XY, UK
| | - J Paul Luzio
- Department of Clinical Biochemistry and Cambridge Institute for Medical Research, School of Clinical Medicine, Wellcome Trust/MRC Building, University of Cambridge, Cambridge Biomedical Campus, Hills Road, Cambridge, CB2 0XY, UK.
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Podinovskaia M, Spang A. The Endosomal Network: Mediators and Regulators of Endosome Maturation. ENDOCYTOSIS AND SIGNALING 2018; 57:1-38. [DOI: 10.1007/978-3-319-96704-2_1] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
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Scholz-Starke J. How may PI(3,5)P 2 impact on vacuolar acidification? Channels (Austin) 2017; 11:497-498. [PMID: 28699817 PMCID: PMC5786259 DOI: 10.1080/19336950.2017.1354584] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2017] [Accepted: 07/08/2017] [Indexed: 10/19/2022] Open
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Naufer A, Hipolito VEB, Ganesan S, Prashar A, Zaremberg V, Botelho RJ, Terebiznik MR. pH of endophagosomes controls association of their membranes with Vps34 and PtdIns(3)P levels. J Cell Biol 2017; 217:329-346. [PMID: 29089378 PMCID: PMC5748975 DOI: 10.1083/jcb.201702179] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2017] [Revised: 09/03/2017] [Accepted: 09/26/2017] [Indexed: 12/19/2022] Open
Abstract
Specific changes in phospholipid content are a hallmark of the membranes of maturing endosomes and phagosomes, but is it unclear how this is controlled. Naufer et al. now show that acidification of the lumen of endosomes and phagosomes triggers dissociation of the Vps34 lipid kinase from these organelles, which terminates PtdIns(3)P synthesis and signaling. Phagocytosis of filamentous bacteria occurs through tubular phagocytic cups (tPCs) and takes many minutes to engulf these filaments into phagosomes. Contravening the canonical phagocytic pathway, tPCs mature by fusing with endosomes. Using this model, we observed the sequential recruitment of early and late endolysosomal markers to the elongating tPCs. Surprisingly, the regulatory early endosomal lipid phosphatidylinositol-3-phosphate (PtdIns(3)P) persists on tPCs as long as their luminal pH remains neutral. Interestingly, by manipulating cellular pH, we determined that PtdIns(3)P behaves similarly in canonical phagosomes as well as endosomes. We found that this is the product of a pH-based mechanism that induces the dissociation of the Vps34 class III phosphatidylinositol-3-kinase from these organelles as they acidify. The detachment of Vps34 stops the production of PtdIns(3)P, allowing for the turnover of this lipid by PIKfyve. Given that PtdIns(3)P-dependent signaling is important for multiple cellular pathways, this mechanism for pH-dependent regulation of Vps34 could be at the center of many PtdIns(3)P-dependent cellular processes.
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Affiliation(s)
- Amriya Naufer
- Department of Biological Sciences, University of Toronto Scarborough, Toronto, Canada.,Department of Cell and System Biology, University of Toronto Scarborough, Toronto, Canada
| | - Victoria E B Hipolito
- Molecular Science Graduate Program, Ryerson University, Toronto, Canada.,Department of Chemistry and Biology, Ryerson University, Toronto, Canada
| | | | - Akriti Prashar
- Department of Biological Sciences, University of Toronto Scarborough, Toronto, Canada.,Department of Cell and System Biology, University of Toronto Scarborough, Toronto, Canada
| | - Vanina Zaremberg
- Department of Biological Sciences, University of Calgary, Calgary, Canada
| | - Roberto J Botelho
- Molecular Science Graduate Program, Ryerson University, Toronto, Canada .,Department of Chemistry and Biology, Ryerson University, Toronto, Canada
| | - Mauricio R Terebiznik
- Department of Biological Sciences, University of Toronto Scarborough, Toronto, Canada .,Department of Cell and System Biology, University of Toronto Scarborough, Toronto, Canada
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