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Coulter AM, Cortés V, Theodore CJ, Cianciolo RE, Korstanje R, Campellone KG. WHAMM functions in kidney reabsorption and polymerizes actin to promote autophagosomal membrane closure and cargo sequestration. Mol Biol Cell 2024; 35:ar80. [PMID: 38598293 DOI: 10.1091/mbc.e24-01-0025] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/12/2024] Open
Abstract
The actin cytoskeleton is essential for many functions of eukaryotic cells, but the factors that nucleate actin assembly are not well understood at the organismal level or in the context of disease. To explore the function of the actin nucleation factor WHAMM in mice, we examined how Whamm inactivation impacts kidney physiology and cellular proteostasis. We show that male WHAMM knockout mice excrete elevated levels of albumin, glucose, phosphate, and amino acids, and display structural abnormalities of the kidney proximal tubule, suggesting that WHAMM activity is important for nutrient reabsorption. In kidney tissue, the loss of WHAMM results in the accumulation of the lipidated autophagosomal membrane protein LC3, indicating an alteration in autophagy. In mouse fibroblasts and human proximal tubule cells, WHAMM and its binding partner the Arp2/3 complex control autophagic membrane closure and cargo receptor recruitment. These results reveal a role for WHAMM-mediated actin assembly in maintaining kidney function and promoting proper autophagosome membrane remodeling.
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Affiliation(s)
- Alyssa M Coulter
- Department of Molecular & Cell Biology, Institute for Systems Genomics, University of Connecticut, Storrs, CT 06269
| | | | - Corey J Theodore
- Department of Molecular & Cell Biology, Institute for Systems Genomics, University of Connecticut, Storrs, CT 06269
| | | | | | - Kenneth G Campellone
- Department of Molecular & Cell Biology, Institute for Systems Genomics, University of Connecticut, Storrs, CT 06269
- Center on Aging, UConn Health, Farmington, CT 06030
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2
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Theodore CJ, Wagner LH, Campellone KG. Autophagosome turnover requires Arp2/3 complex-mediated maintenance of lysosomal integrity. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.03.12.584718. [PMID: 38559247 PMCID: PMC10980047 DOI: 10.1101/2024.03.12.584718] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/04/2024]
Abstract
Autophagy is an intracellular degradation process that maintains homeostasis, responds to stress, and plays key roles in the prevention of aging and disease. Autophagosome biogenesis, vesicle rocketing, and autolysosome tubulation are controlled by multiple actin nucleation factors, but the impact of actin assembly on completion of the autophagic pathway is not well understood. Here we studied autophagosome and lysosome remodeling in fibroblasts harboring an inducible knockout (iKO) of the Arp2/3 complex, an essential actin nucleator. Arp2/3 complex ablation resulted in increased basal levels of autophagy receptors and lipidated membrane proteins from the LC3 and GABARAP families. Under both steady-state and starvation conditions, Arp2/3 iKO cells accumulated abnormally high numbers of autolysosomes, suggesting a defect in autophagic flux. The inability of Arp2/3 complex-deficient cells to complete autolysosome degradation and turnover is explained by the presence of damaged, leaky lysosomes. In cells treated with an acute lysosomal membrane-damaging agent, the Arp2/3-activating protein WHAMM is recruited to lysosomes, where Arp2/3 complex-dependent actin assembly is crucial for restoring intact lysosomal structure. These results establish the Arp2/3 complex as a central player late in the canonical autophagy pathway and reveal a new role for the actin nucleation machinery in maintaining lysosomal integrity.
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Affiliation(s)
- Corey J. Theodore
- Department of Molecular and Cell Biology; University of Connecticut, Storrs CT, USA
- Institute for Systems Genomics; University of Connecticut, Storrs CT, USA
| | - Lianna H. Wagner
- Department of Molecular and Cell Biology; University of Connecticut, Storrs CT, USA
- Institute for Systems Genomics; University of Connecticut, Storrs CT, USA
| | - Kenneth G. Campellone
- Department of Molecular and Cell Biology; University of Connecticut, Storrs CT, USA
- Institute for Systems Genomics; University of Connecticut, Storrs CT, USA
- Center on Aging, UConn Health; University of Connecticut, Storrs CT, USA
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3
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Coulter AM, Cortés V, Theodore CJ, Cianciolo RE, Korstanje R, Campellone KG. WHAMM functions in kidney reabsorption and polymerizes actin to promote autophagosomal membrane closure and cargo sequestration. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.01.22.576497. [PMID: 38328079 PMCID: PMC10849548 DOI: 10.1101/2024.01.22.576497] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/09/2024]
Abstract
The actin cytoskeleton is essential for many functions of eukaryotic cells, but the factors that nucleate actin assembly are not well understood at the organismal level or in the context of disease. To explore the function of the actin nucleation factor WHAMM in mice, we examined how Whamm inactivation impacts kidney physiology and cellular proteostasis. We show that male WHAMM knockout mice excrete elevated levels of albumin, glucose, phosphate, and amino acids, and display abnormalities of the kidney proximal tubule, suggesting that WHAMM activity is important for nutrient reabsorption. In kidney tissue, the loss of WHAMM results in the accumulation of the lipidated autophagosomal membrane protein LC3, indicating an alteration in autophagy. In mouse fibroblasts and human proximal tubule cells, WHAMM and its binding partner the Arp2/3 complex control autophagic membrane closure and cargo receptor recruitment. These results reveal a role for WHAMM-mediated actin assembly in maintaining kidney function and promoting proper autophagosome membrane remodeling.
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Affiliation(s)
- Alyssa M Coulter
- Department of Molecular & Cell Biology, Institute for Systems Genomics; University of Connecticut, Storrs CT, USA
| | | | - Corey J Theodore
- Department of Molecular & Cell Biology, Institute for Systems Genomics; University of Connecticut, Storrs CT, USA
| | | | | | - Kenneth G Campellone
- Department of Molecular & Cell Biology, Institute for Systems Genomics; University of Connecticut, Storrs CT, USA
- Center on Aging; UConn Health, Farmington CT, USA
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4
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Martinek J, Cifrová P, Vosolsobě S, García-González J, Malínská K, Mauerová Z, Jelínková B, Krtková J, Sikorová L, Leaves I, Sparkes I, Schwarzerová K. ARP2/3 complex associates with peroxisomes to participate in pexophagy in plants. NATURE PLANTS 2023; 9:1874-1889. [PMID: 37845336 DOI: 10.1038/s41477-023-01542-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/25/2022] [Accepted: 09/11/2023] [Indexed: 10/18/2023]
Abstract
Actin-related protein (ARP2/3) complex is a heteroheptameric protein complex, evolutionary conserved in all eukaryotic organisms. Its conserved role is based on the induction of actin polymerization at the interface between membranes and the cytoplasm. Plant ARP2/3 has been reported to participate in actin reorganization at the plasma membrane during polarized growth of trichomes and at the plasma membrane-endoplasmic reticulum contact sites. Here we demonstrate that individual plant subunits of ARP2/3 fused to fluorescent proteins form motile spot-like structures in the cytoplasm that are associated with peroxisomes in Arabidopsis and tobacco. ARP2/3 is found at the peroxisome periphery and contains the assembled ARP2/3 complex and the WAVE/SCAR complex subunit NAP1. This ARP2/3-positive peroxisomal domain colocalizes with the autophagosome and, under conditions that affect the autophagy, colocalization between ARP2/3 and the autophagosome increases. ARP2/3 subunits co-immunoprecipitate with ATG8f and peroxisome-associated ARP2/3 interact in vivo with the ATG8f marker. Since mutants lacking functional ARP2/3 complex have more peroxisomes than wild type, we suggest that ARP2/3 has a novel role in the process of peroxisome degradation by autophagy, called pexophagy.
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Affiliation(s)
- Jan Martinek
- Department of Experimental Plant Biology, Faculty of Science, Charles University, Prague, Czech Republic
| | - Petra Cifrová
- Department of Experimental Plant Biology, Faculty of Science, Charles University, Prague, Czech Republic
| | - Stanislav Vosolsobě
- Department of Experimental Plant Biology, Faculty of Science, Charles University, Prague, Czech Republic
| | - Judith García-González
- Department of Experimental Plant Biology, Faculty of Science, Charles University, Prague, Czech Republic
| | - Kateřina Malínská
- Imaging Facility of Institute of Experimental Botany AS CR, Prague, Czech Republic
| | - Zdeňka Mauerová
- Department of Experimental Plant Biology, Faculty of Science, Charles University, Prague, Czech Republic
| | - Barbora Jelínková
- Department of Experimental Plant Biology, Faculty of Science, Charles University, Prague, Czech Republic
| | - Jana Krtková
- Department of Experimental Plant Biology, Faculty of Science, Charles University, Prague, Czech Republic
| | - Lenka Sikorová
- Department of Experimental Plant Biology, Faculty of Science, Charles University, Prague, Czech Republic
| | - Ian Leaves
- Biosciences, CLES, Exeter University, Exeter, UK
| | - Imogen Sparkes
- School of Biological Sciences, University of Bristol, Bristol, UK
| | - Kateřina Schwarzerová
- Department of Experimental Plant Biology, Faculty of Science, Charles University, Prague, Czech Republic.
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5
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Fung TS, Chakrabarti R, Higgs HN. The multiple links between actin and mitochondria. Nat Rev Mol Cell Biol 2023; 24:651-667. [PMID: 37277471 PMCID: PMC10528321 DOI: 10.1038/s41580-023-00613-y] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/26/2023] [Indexed: 06/07/2023]
Abstract
Actin plays many well-known roles in cells, and understanding any specific role is often confounded by the overlap of multiple actin-based structures in space and time. Here, we review our rapidly expanding understanding of actin in mitochondrial biology, where actin plays multiple distinct roles, exemplifying the versatility of actin and its functions in cell biology. One well-studied role of actin in mitochondrial biology is its role in mitochondrial fission, where actin polymerization from the endoplasmic reticulum through the formin INF2 has been shown to stimulate two distinct steps. However, roles for actin during other types of mitochondrial fission, dependent on the Arp2/3 complex, have also been described. In addition, actin performs functions independent of mitochondrial fission. During mitochondrial dysfunction, two distinct phases of Arp2/3 complex-mediated actin polymerization can be triggered. First, within 5 min of dysfunction, rapid actin assembly around mitochondria serves to suppress mitochondrial shape changes and to stimulate glycolysis. At a later time point, at more than 1 h post-dysfunction, a second round of actin polymerization prepares mitochondria for mitophagy. Finally, actin can both stimulate and inhibit mitochondrial motility depending on the context. These motility effects can either be through the polymerization of actin itself or through myosin-based processes, with myosin 19 being an important mitochondrially attached myosin. Overall, distinct actin structures assemble in response to diverse stimuli to affect specific changes to mitochondria.
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Affiliation(s)
- Tak Shun Fung
- Department of Biochemistry and Cell Biology, Geisel School of Medicine at Dartmouth College, Hanover, NH, USA
- Department of Cancer Biology and Genetics, Memorial Sloan Kettering Cancer Center, New York, NY, USA
| | - Rajarshi Chakrabarti
- Department of Biochemistry and Cell Biology, Geisel School of Medicine at Dartmouth College, Hanover, NH, USA
- MitoCare Center, Department of Pathology and Genomic Medicine, Thomas Jefferson University, Philadelphia, PA, USA
| | - Henry N Higgs
- Department of Biochemistry and Cell Biology, Geisel School of Medicine at Dartmouth College, Hanover, NH, USA.
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6
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Campellone KG, Lebek NM, King VL. Branching out in different directions: Emerging cellular functions for the Arp2/3 complex and WASP-family actin nucleation factors. Eur J Cell Biol 2023; 102:151301. [PMID: 36907023 DOI: 10.1016/j.ejcb.2023.151301] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2022] [Revised: 02/07/2023] [Accepted: 02/25/2023] [Indexed: 03/06/2023] Open
Abstract
The actin cytoskeleton impacts practically every function of a eukaryotic cell. Historically, the best-characterized cytoskeletal activities are in cell morphogenesis, motility, and division. The structural and dynamic properties of the actin cytoskeleton are also crucial for establishing, maintaining, and changing the organization of membrane-bound organelles and other intracellular structures. Such activities are important in nearly all animal cells and tissues, although distinct anatomical regions and physiological systems rely on different regulatory factors. Recent work indicates that the Arp2/3 complex, a broadly expressed actin nucleator, drives actin assembly during several intracellular stress response pathways. These newly described Arp2/3-mediated cytoskeletal rearrangements are coordinated by members of the Wiskott-Aldrich Syndrome Protein (WASP) family of actin nucleation-promoting factors. Thus, the Arp2/3 complex and WASP-family proteins are emerging as crucial players in cytoplasmic and nuclear activities including autophagy, apoptosis, chromatin dynamics, and DNA repair. Characterizations of the functions of the actin assembly machinery in such stress response mechanisms are advancing our understanding of both normal and pathogenic processes, and hold great promise for providing insights into organismal development and interventions for disease.
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Affiliation(s)
- Kenneth G Campellone
- Department of Molecular and Cell Biology, Institute for Systems Genomics; University of Connecticut; Storrs, CT, USA.
| | - Nadine M Lebek
- Department of Molecular and Cell Biology, Institute for Systems Genomics; University of Connecticut; Storrs, CT, USA
| | - Virginia L King
- Department of Molecular and Cell Biology, Institute for Systems Genomics; University of Connecticut; Storrs, CT, USA
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Ali Alghamdi M, Benabdelkamel H, Masood A, Saheb Sharif-Askari N, Hachim MY, Alsheikh H, Hamad MH, Salih MA, Bashiri FA, Alhasan K, Kashour T, Guatibonza Moreno P, Schröder S, Karageorgou V, Bertoli-Avella AM, Alkhalidi H, Jamjoom DZ, Alorainy IA, Alfadda AA, Halwani R. Genomic, Proteomic, and Phenotypic Spectrum of Novel O-Sialoglycoprotein Endopeptidase Variant in Four Affected Individuals With Galloway-Mowat Syndrome. Front Genet 2022; 13:806190. [PMID: 35812735 PMCID: PMC9259880 DOI: 10.3389/fgene.2022.806190] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2021] [Accepted: 03/16/2022] [Indexed: 11/15/2022] Open
Abstract
Galloway-Mowat syndrome is a rare autosomal recessive disease characterized by a unique combination of renal and neurological manifestations, including early-onset steroid-resistant nephrotic syndrome, microcephaly, psychomotor delay, and gyral abnormalities of the brain. Most patients die during early childhood. Here, we identified a novel homozygous O-sialoglycoprotein endopeptidase (OSGEP) variant, NM_017807.3:c.973C>G (p.Arg325Gly), in four affected individuals in an extended consanguineous family from Saudi Arabia. We have described the detailed clinical characterization, brain imaging results, and muscle biopsy findings. The described phenotype varied from embryonic lethality to early pregnancy loss or death at the age of 9. Renal disease is often the cause of death. Protein modeling of this OSGEP variant confirmed its pathogenicity. In addition, proteomic analysis of the affected patients proposed a link between the KEOPS complex function and human pathology and suggested potential pathogenic mechanisms.
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Affiliation(s)
- Malak Ali Alghamdi
- Pediatric Department, College of Medicine, King Saud University, Riyadh, Saudi Arabia
- Medical Genetics Division, Department of Pediatrics, King Saud University, Riyadh, Saudi Arabia
- *Correspondence: Malak Ali Alghamdi,
| | - Hicham Benabdelkamel
- Proteomics Resource Unit, Obesity Research Center, College of Medicine, King Saud University, Riyadh, Saudi Arabia
| | - Afshan Masood
- Proteomics Resource Unit, Obesity Research Center, College of Medicine, King Saud University, Riyadh, Saudi Arabia
| | | | - Mahmood Y. Hachim
- College of Medicine, Mohammed Bin Rashid University of Medicine and Health Sciences, Dubai, United Arab Emirates
| | - Hamad Alsheikh
- Neurology Division, Department of Pediatrics, King Saud University, Riyadh, Saudi Arabia
| | - Muddathir H. Hamad
- Neurology Division, Department of Pediatrics, King Saud University, Riyadh, Saudi Arabia
| | - Mustafa A. Salih
- Pediatric Department, College of Medicine, King Saud University, Riyadh, Saudi Arabia
| | - Fahad A. Bashiri
- Pediatric Department, College of Medicine, King Saud University, Riyadh, Saudi Arabia
- Neurology Division, Department of Pediatrics, King Saud University, Riyadh, Saudi Arabia
| | - Khalid Alhasan
- Pediatric Department, College of Medicine, King Saud University, Riyadh, Saudi Arabia
- Nephology Division, Department of Pediatrics, King Saud University, Riyadh, Saudi Arabia
- Pediatric Kidney Transplant Division,Organ Transplant Center, King Faisal Specialist Hospital and Research Centre, Riyadh, Saudi Arabia
| | - Tarek Kashour
- Cardiology Department, College of Medicine, King Saud University, Riyadh, Saudi Arabia
| | | | | | | | | | - Hisham Alkhalidi
- Pathology Department, College of Medicine, King Saud University, Riyadh, Saudi Arabia
| | - Dima Z. Jamjoom
- Radiology and Medical Imaging Department, College of Medicine, King Saud University, Riyadh, Saudi Arabia
| | - Ibrahim A. Alorainy
- Radiology and Medical Imaging Department, College of Medicine, King Saud University, Riyadh, Saudi Arabia
| | - Assim A. Alfadda
- Proteomics Resource Unit, Obesity Research Center, College of Medicine, King Saud University, Riyadh, Saudi Arabia
- Department of Medicine, College of Medicine and King Saud Medical City, King Saud University, Riyadh, Saudi Arabia
- Strategic Center for Diabetes Research, College of Medicine, King Saud University, Riyadh, Saudi Arabia
| | - Rabih Halwani
- Department of Clinical Sciences, College of Medicine, Sharjah Institute for Medical Research (SIMR), University of Sharjah, Sharjah, United Arab Emirates
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Kramer DA, Piper HK, Chen B. WASP family proteins: Molecular mechanisms and implications in human disease. Eur J Cell Biol 2022; 101:151244. [PMID: 35667337 PMCID: PMC9357188 DOI: 10.1016/j.ejcb.2022.151244] [Citation(s) in RCA: 17] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2022] [Revised: 05/25/2022] [Accepted: 05/27/2022] [Indexed: 02/08/2023] Open
Abstract
Proteins of the Wiskott-Aldrich syndrome protein (WASP) family play a central role in regulating actin cytoskeletal dynamics in a wide range of cellular processes. Genetic mutations or misregulation of these proteins are tightly associated with many diseases. The WASP-family proteins act by transmitting various upstream signals to their conserved WH2-Central-Acidic (WCA) peptide sequence at the C-terminus, which in turn binds to the Arp2/3 complex to stimulate the formation of branched actin networks at membranes. Despite this common feature, the regulatory mechanisms and cellular functions of distinct WASP-family proteins are very different. Here, we summarize and clarify our current understanding of WASP-family proteins and how disruption of their functions is related to human disease.
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Affiliation(s)
- Daniel A Kramer
- Roy J. Carver Department of Biochemistry, Biophysics & Molecular Biology, Iowa State University, 2437 Pammel Drive, Ames, IA 50011, USA
| | - Hannah K Piper
- Roy J. Carver Department of Biochemistry, Biophysics & Molecular Biology, Iowa State University, 2437 Pammel Drive, Ames, IA 50011, USA
| | - Baoyu Chen
- Roy J. Carver Department of Biochemistry, Biophysics & Molecular Biology, Iowa State University, 2437 Pammel Drive, Ames, IA 50011, USA.
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Fung TS, Chakrabarti R, Kollasser J, Rottner K, Stradal TE, Kage F, Higgs HN. Parallel kinase pathways stimulate actin polymerization at depolarized mitochondria. Curr Biol 2022; 32:1577-1592.e8. [PMID: 35290799 PMCID: PMC9078333 DOI: 10.1016/j.cub.2022.02.058] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2021] [Revised: 02/04/2022] [Accepted: 02/21/2022] [Indexed: 12/31/2022]
Abstract
Mitochondrial damage (MtD) represents a dramatic change in cellular homeostasis, necessitating metabolic changes and stimulating mitophagy. One rapid response to MtD is a rapid peri-mitochondrial actin polymerization termed ADA (acute damage-induced actin). The activation mechanism for ADA is unknown. Here, we use mitochondrial depolarization or the complex I inhibitor metformin to induce ADA. We show that two parallel signaling pathways are required for ADA. In one pathway, increased cytosolic calcium in turn activates PKC-β, Rac, WAVE regulatory complex, and Arp2/3 complex. In the other pathway, a drop in cellular ATP in turn activates AMPK (through LKB1), Cdc42, and FMNL formins. We also identify putative guanine nucleotide exchange factors for Rac and Cdc42, Trio and Fgd1, respectively, whose phosphorylation states increase upon mitochondrial depolarization and whose suppression inhibits ADA. The depolarization-induced calcium increase is dependent on the mitochondrial sodium-calcium exchanger NCLX, suggesting initial mitochondrial calcium efflux. We also show that ADA inhibition results in enhanced mitochondrial shape changes upon mitochondrial depolarization, suggesting that ADA inhibits these shape changes. These depolarization-induced shape changes are not fragmentation but a circularization of the inner mitochondrial membrane, which is dependent on the inner mitochondrial membrane protease Oma1. ADA inhibition increases the proteolytic processing of an Oma1 substrate, the dynamin GTPase Opa1. These results show that ADA requires the combined action of the Arp2/3 complex and formin proteins to polymerize a network of actin filaments around mitochondria and that the ADA network inhibits the rapid mitochondrial shape changes that occur upon mitochondrial depolarization.
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Miyazaki M, Hiramoto M, Takano N, Kokuba H, Takemura J, Tokuhisa M, Hino H, Kazama H, Miyazawa K. Targeted disruption of GAK stagnates autophagic flux by disturbing lysosomal dynamics. Int J Mol Med 2021; 48:195. [PMID: 34468012 PMCID: PMC8416139 DOI: 10.3892/ijmm.2021.5028] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2021] [Accepted: 08/05/2021] [Indexed: 01/13/2023] Open
Abstract
The autophagy-lysosome system allows cells to adapt to environmental changes by regulating the degradation and recycling of cellular components, and to maintain homeostasis by removing aggregated proteins and defective organelles. Cyclin G-associated kinase (GAK) is involved in the regulation of clathrin-dependent endocytosis and cell cycle progression. In addition, a single nucleotide polymorphism at the GAK locus has been reported as a risk factor for Parkinson's disease. However, the roles of GAK in the autophagy-lysosome system are not completely understood, thus the present study aimed to clarify this. In the present study, under genetic disruption or chemical inhibition of GAK, analyzing autophagic flux and observing morphological changes of autophagosomes and autolysosomes revealed that GAK controlled lysosomal dynamics via actomyosin regulation, resulting in a steady progression of autophagy. GAK knockout (KO) in A549 cells impaired autophagosome-lysosome fusion and autophagic lysosome reformation, which resulted in the accumulation of enlarged autophagosomes and autolysosomes during prolonged starvation. The stagnation of autophagic flux accompanied by these phenomena was also observed with the addition of a GAK inhibitor. Furthermore, the addition of Rho-associated protein kinase (ROCK) inhibitor or ROCK1 knockdown mitigated GAK KO-mediated effects. The results suggested a vital role of GAK in controlling lysosomal dynamics via maintaining lysosomal homeostasis during autophagy.
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Affiliation(s)
- Masaya Miyazaki
- Department of Biochemistry, Tokyo Medical University, Tokyo 160‑8402, Japan
| | - Masaki Hiramoto
- Department of Biochemistry, Tokyo Medical University, Tokyo 160‑8402, Japan
| | - Naoharu Takano
- Department of Biochemistry, Tokyo Medical University, Tokyo 160‑8402, Japan
| | - Hiroko Kokuba
- Laboratory of Electron Microscopy, Tokyo Medical University, Tokyo 160‑8402, Japan
| | - Jun Takemura
- Department of Biochemistry, Tokyo Medical University, Tokyo 160‑8402, Japan
| | - Mayumi Tokuhisa
- Department of Biochemistry, Tokyo Medical University, Tokyo 160‑8402, Japan
| | - Hirotsugu Hino
- Department of Biochemistry, Tokyo Medical University, Tokyo 160‑8402, Japan
| | - Hiromi Kazama
- Department of Biochemistry, Tokyo Medical University, Tokyo 160‑8402, Japan
| | - Keisuke Miyazawa
- Department of Biochemistry, Tokyo Medical University, Tokyo 160‑8402, Japan
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11
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Chakrabarti R, Lee M, Higgs HN. Multiple roles for actin in secretory and endocytic pathways. Curr Biol 2021; 31:R603-R618. [PMID: 34033793 DOI: 10.1016/j.cub.2021.03.038] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Actin filaments play multiple roles in the secretory pathway and in endosome dynamics in mammals, including maintenance of Golgi structure, release of membrane cargo from the trans-Golgi network (TGN), endocytosis, and endosomal sorting dynamics. In addition, TGN carrier transport and endocytosis both occur by multiple mechanisms in mammals. Actin likely plays a role in at least four mammalian endocytic pathways, five pathways for membrane release from the TGN, and three processes involving endosomes. Also, the mammalian Golgi structure is highly dynamic, and actin is likely important for these dynamics. One challenge for many of these processes is the need to deal with other membrane-associated structures, such as the cortical actin network at the plasma membrane or the matrix that surrounds the Golgi. Arp2/3 complex is a major actin assembly factor in most of the processes mentioned, but roles for formins and tandem WH2-motif-containing assembly factors are being elucidated and are anticipated to grow with further study. The specific role for actin has not been defined for most of these processes, but is likely to involve the generation of force for membrane dynamics, either by actin polymerization itself or by myosin motor activity. Defining these processes mechanistically is necessary for understanding membrane dynamics in general, as well as pathways that utilize these processes, such as autophagy.
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Affiliation(s)
- Rajarshi Chakrabarti
- Department of Biochemistry and Cell Biology, Geisel School of Medicine at Dartmouth, Hanover, NH 03755, USA
| | - Miriam Lee
- Department of Biochemistry and Cell Biology, Geisel School of Medicine at Dartmouth, Hanover, NH 03755, USA
| | - Henry N Higgs
- Department of Biochemistry and Cell Biology, Geisel School of Medicine at Dartmouth, Hanover, NH 03755, USA.
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12
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The actin nucleation factors JMY and WHAMM enable a rapid Arp2/3 complex-mediated intrinsic pathway of apoptosis. PLoS Genet 2021; 17:e1009512. [PMID: 33872315 PMCID: PMC8084344 DOI: 10.1371/journal.pgen.1009512] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2020] [Revised: 04/29/2021] [Accepted: 03/28/2021] [Indexed: 01/02/2023] Open
Abstract
The actin cytoskeleton is a well-known player in most vital cellular processes, but comparably little is understood about how the actin assembly machinery impacts programmed cell death pathways. In the current study, we explored roles for the human Wiskott-Aldrich Syndrome Protein (WASP) family of actin nucleation factors in DNA damage-induced apoptosis. Inactivation of each WASP-family gene revealed that two of them, JMY and WHAMM, are necessary for rapid apoptotic responses. JMY and WHAMM participate in a p53-dependent cell death pathway by enhancing mitochondrial permeabilization, initiator caspase cleavage, and executioner caspase activation. JMY-mediated apoptosis requires actin nucleation via the Arp2/3 complex, and actin filaments are assembled in cytoplasmic territories containing clusters of cytochrome c and active caspase-3. The loss of JMY additionally results in significant changes in gene expression, including upregulation of the WHAMM-interacting G-protein RhoD. Depletion or deletion of RHOD increases cell death, suggesting that RhoD normally contributes to cell survival. These results give rise to a model in which JMY and WHAMM promote intrinsic cell death responses that can be opposed by RhoD.
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13
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Hernández-Cáceres MP, Munoz L, Pradenas JM, Pena F, Lagos P, Aceiton P, Owen GI, Morselli E, Criollo A, Ravasio A, Bertocchi C. Mechanobiology of Autophagy: The Unexplored Side of Cancer. Front Oncol 2021; 11:632956. [PMID: 33718218 PMCID: PMC7952994 DOI: 10.3389/fonc.2021.632956] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2020] [Accepted: 02/01/2021] [Indexed: 12/12/2022] Open
Abstract
Proper execution of cellular function, maintenance of cellular homeostasis and cell survival depend on functional integration of cellular processes and correct orchestration of cellular responses to stresses. Cancer transformation is a common negative consequence of mismanagement of coordinated response by the cell. In this scenario, by maintaining the balance among synthesis, degradation, and recycling of cytosolic components including proteins, lipids, and organelles the process of autophagy plays a central role. Several environmental stresses activate autophagy, among those hypoxia, DNA damage, inflammation, and metabolic challenges such as starvation. In addition to these chemical challenges, there is a requirement for cells to cope with mechanical stresses stemming from their microenvironment. Cells accomplish this task by activating an intrinsic mechanical response mediated by cytoskeleton active processes and through mechanosensitive protein complexes which interface the cells with their mechano-environment. Despite autophagy and cell mechanics being known to play crucial transforming roles during oncogenesis and malignant progression their interplay is largely overlooked. In this review, we highlight the role of physical forces in autophagy regulation and their potential implications in both physiological as well as pathological conditions. By taking a mechanical perspective, we wish to stimulate novel questions to further the investigation of the mechanical requirements of autophagy and appreciate the extent to which mechanical signals affect this process.
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Affiliation(s)
- Maria Paz Hernández-Cáceres
- Laboratory of Autophagy and Metabolism, Department of Physiology, Faculty of Biological Sciences, Pontificia Universidad Católica De Chile, Santiago, Chile
| | - Leslie Munoz
- Laboratory for Mechanobiology of Transforming Systems, Institute for Biological and Medical Engineering, Schools of Engineering, Medicine and Biological Sciences, Pontificia Universidad Católica de Chile, Santiago, Chile
- Laboratory for Molecular Mechanics of Cell Adhesion, Department of Physiology, Faculty of Biological Sciences, Pontificia Universidad Católica De Chile, Santiago, Chile
| | - Javiera M. Pradenas
- Advanced Center for Chronic Diseases (ACCDiS), Santiago, Chile
- Laboratory of Investigation in Oncology, Faculty of Biological Sciences Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Francisco Pena
- Laboratory for Mechanobiology of Transforming Systems, Institute for Biological and Medical Engineering, Schools of Engineering, Medicine and Biological Sciences, Pontificia Universidad Católica de Chile, Santiago, Chile
- Laboratory for Molecular Mechanics of Cell Adhesion, Department of Physiology, Faculty of Biological Sciences, Pontificia Universidad Católica De Chile, Santiago, Chile
| | - Pablo Lagos
- Laboratory of Autophagy and Metabolism, Department of Physiology, Faculty of Biological Sciences, Pontificia Universidad Católica De Chile, Santiago, Chile
| | - Pablo Aceiton
- Laboratory for Mechanobiology of Transforming Systems, Institute for Biological and Medical Engineering, Schools of Engineering, Medicine and Biological Sciences, Pontificia Universidad Católica de Chile, Santiago, Chile
- Laboratory for Molecular Mechanics of Cell Adhesion, Department of Physiology, Faculty of Biological Sciences, Pontificia Universidad Católica De Chile, Santiago, Chile
| | - Gareth I. Owen
- Advanced Center for Chronic Diseases (ACCDiS), Santiago, Chile
- Laboratory of Investigation in Oncology, Faculty of Biological Sciences Pontificia Universidad Católica de Chile, Santiago, Chile
- Millennium Institute on Immunology and Immunotherapy, Santiago, Chile
| | - Eugenia Morselli
- Laboratory of Autophagy and Metabolism, Department of Physiology, Faculty of Biological Sciences, Pontificia Universidad Católica De Chile, Santiago, Chile
- Autophagy Research Center, Santiago de Chile, Chile
| | - Alfredo Criollo
- Advanced Center for Chronic Diseases (ACCDiS), Santiago, Chile
- Autophagy Research Center, Santiago de Chile, Chile
- Facultad De Odontología, Instituto De Investigación En Ciencias Odontológicas (ICOD), Universidad De Chile, Santiago, Chile
| | - Andrea Ravasio
- Laboratory for Mechanobiology of Transforming Systems, Institute for Biological and Medical Engineering, Schools of Engineering, Medicine and Biological Sciences, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Cristina Bertocchi
- Laboratory for Molecular Mechanics of Cell Adhesion, Department of Physiology, Faculty of Biological Sciences, Pontificia Universidad Católica De Chile, Santiago, Chile
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Kabrawala S, Zimmer MD, Campellone KG. WHIMP links the actin nucleation machinery to Src-family kinase signaling during protrusion and motility. PLoS Genet 2020; 16:e1008694. [PMID: 32196488 PMCID: PMC7112243 DOI: 10.1371/journal.pgen.1008694] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2019] [Revised: 04/01/2020] [Accepted: 02/22/2020] [Indexed: 12/27/2022] Open
Abstract
Cell motility is governed by cooperation between the Arp2/3 complex and nucleation-promoting factors from the Wiskott-Aldrich Syndrome Protein (WASP) family, which together assemble actin filament networks to drive membrane protrusion. Here we identify WHIMP (WAVE Homology In Membrane Protrusions) as a new member of the WASP family. The Whimp gene is encoded on the X chromosome of a subset of mammals, including mice. Murine WHIMP promotes Arp2/3-dependent actin assembly, but is less potent than other nucleation factors. Nevertheless, WHIMP-mediated Arp2/3 activation enhances both plasma membrane ruffling and wound healing migration, whereas WHIMP depletion impairs protrusion and slows motility. WHIMP expression also increases Src-family kinase activity, and WHIMP-induced ruffles contain the additional nucleation-promoting factors WAVE1, WAVE2, and N-WASP, but not JMY or WASH. Perturbing the function of Src-family kinases, WAVE proteins, or Arp2/3 complex inhibits WHIMP-driven ruffling. These results suggest that WHIMP-associated actin assembly plays a direct role in membrane protrusion, but also results in feedback control of tyrosine kinase signaling to modulate the activation of multiple WASP-family members. The actin cytoskeleton is a collection of protein polymers that assemble and disassemble within cells at specific times and locations. Sophisticated cytoskeletal regulators called nucleation-promoting factors ensure that actin polymerizes when and where it is needed, and many of these factors are members of the Wiskott-Aldrich Syndrome Protein (WASP) family. Several of the 8 known WASP-family proteins function in cell motility, but how the different factors collaborate with one another is not well understood. In this study, we identified WHIMP, a new WASP-family member that is encoded on the X chromosome of a variety of mammals. In mouse cells, WHIMP enhances cell motility by assembling actin filaments that push the plasma membrane forward. Unexpectedly, WHIMP also activates tyrosine kinases, enzymes that stimulate multiple WASP-family members during motility. Our results open new avenues of research into how nucleation factors cooperate during movement and how the molecular activities that underlie motility differ in distinct cell types and organisms.
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Affiliation(s)
- Shail Kabrawala
- Department of Molecular and Cell Biology, Institute for Systems Genomics, University of Connecticut, Storrs, Connecticut, United States of America
| | - Margaret D. Zimmer
- Department of Molecular and Cell Biology, Institute for Systems Genomics, University of Connecticut, Storrs, Connecticut, United States of America
| | - Kenneth G. Campellone
- Department of Molecular and Cell Biology, Institute for Systems Genomics, University of Connecticut, Storrs, Connecticut, United States of America
- * E-mail:
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15
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Doubravská L, Dostál V, Knop F, Libusová L, Macůrková M. Human myotubularin-related protein 9 regulates ER-to-Golgi trafficking and modulates WNT3A secretion. Exp Cell Res 2020; 386:111709. [PMID: 31704058 DOI: 10.1016/j.yexcr.2019.111709] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2019] [Revised: 10/10/2019] [Accepted: 10/31/2019] [Indexed: 11/29/2022]
Abstract
Regulation of phosphatidylinositol phosphates plays a crucial role in signal transduction, membrane trafficking or autophagy. Members of the myotubularin family of lipid phosphatases contribute to phosphoinositide metabolism by counteracting the activity of phosphoinositide kinases. The mechanisms determining their subcellular localization and targeting to specific membrane compartments are still poorly understood. We show here that the inactive phosphatase MTMR9 localizes to the intermediate compartment and to the Golgi apparatus and is able to recruit its active phosphatase partners MTMR6 and MTMR8 to these locations. Furthermore, MTMR8 and MTMR9 co-localize with the small GTPase RAB1A and regulate its localization. Loss of MTMR9 expression compromises the integrity of the Golgi apparatus and results in altered distribution of RAB1A and actin nucleation-promoting factor WHAMM. Loss or overexpression of MTMR9 leads to decreased rate of protein secretion. We demonstrate that secretion of physiologically relevant cargo exemplified by the WNT3A protein is affected after perturbation of MTMR9 levels.
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Affiliation(s)
- Lenka Doubravská
- Department of Cell Biology, Faculty of Science, Charles University, Viničná 7, 128 00, Prague 2, Czech Republic
| | - Vojtěch Dostál
- Department of Cell Biology, Faculty of Science, Charles University, Viničná 7, 128 00, Prague 2, Czech Republic
| | - Filip Knop
- Department of Cell Biology, Faculty of Science, Charles University, Viničná 7, 128 00, Prague 2, Czech Republic
| | - Lenka Libusová
- Department of Cell Biology, Faculty of Science, Charles University, Viničná 7, 128 00, Prague 2, Czech Republic
| | - Marie Macůrková
- Department of Cell Biology, Faculty of Science, Charles University, Viničná 7, 128 00, Prague 2, Czech Republic.
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16
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Singla A, Fedoseienko A, Giridharan SSP, Overlee BL, Lopez A, Jia D, Song J, Huff-Hardy K, Weisman L, Burstein E, Billadeau DD. Endosomal PI(3)P regulation by the COMMD/CCDC22/CCDC93 (CCC) complex controls membrane protein recycling. Nat Commun 2019; 10:4271. [PMID: 31537807 PMCID: PMC6753146 DOI: 10.1038/s41467-019-12221-6] [Citation(s) in RCA: 58] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2018] [Accepted: 08/21/2019] [Indexed: 01/04/2023] Open
Abstract
Protein recycling through the endolysosomal system relies on molecular assemblies that interact with cargo proteins, membranes, and effector molecules. Among them, the COMMD/CCDC22/CCDC93 (CCC) complex plays a critical role in recycling events. While CCC is closely associated with retriever, a cargo recognition complex, its mechanism of action remains unexplained. Herein we show that CCC and retriever are closely linked through sharing a common subunit (VPS35L), yet the integrity of CCC, but not retriever, is required to maintain normal endosomal levels of phosphatidylinositol-3-phosphate (PI(3)P). CCC complex depletion leads to elevated PI(3)P levels, enhanced recruitment and activation of WASH (an actin nucleation promoting factor), excess endosomal F-actin and trapping of internalized receptors. Mechanistically, we find that CCC regulates the phosphorylation and endosomal recruitment of the PI(3)P phosphatase MTMR2. Taken together, we show that the regulation of PI(3)P levels by the CCC complex is critical to protein recycling in the endosomal compartment. Recycling of proteins that have entered the endosome is essential to homeostasis. The COMMD/CCDC22/CCDC93 (CCC) complex is regulator of recycling but the molecular mechanisms are unclear. Here, the authors report that the CCC complex regulates endosomal recycling by maintaining PI3P levels on endosomal membranes.
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Affiliation(s)
- Amika Singla
- Department of Internal Medicine, and Department of Molecular Biology, University of Texas Southwestern Medical Center, Dallas, TX, 75390, USA
| | - Alina Fedoseienko
- Division of Oncology Research and Department of Biochemistry and Molecular Biology, College of Medicine, Mayo Clinic, Rochester, MN, 55905, USA
| | - Sai S P Giridharan
- Life Sciences Institute, University of Michigan, Ann Arbor, MI, 48109, USA
| | - Brittany L Overlee
- Division of Oncology Research and Department of Biochemistry and Molecular Biology, College of Medicine, Mayo Clinic, Rochester, MN, 55905, USA
| | - Adam Lopez
- Department of Internal Medicine, and Department of Molecular Biology, University of Texas Southwestern Medical Center, Dallas, TX, 75390, USA
| | - Da Jia
- Key Laboratory of Birth Defects and Related Diseases of Women and Children, Department of Paediatrics, Division of Neurology, West China Second University Hospital, State Key Laboratory of Biotherapy and Collaborative Innovation Center of Biotherapy, Sichuan University, Chengdu, 610041, China
| | - Jie Song
- Department of Internal Medicine, and Department of Molecular Biology, University of Texas Southwestern Medical Center, Dallas, TX, 75390, USA
| | - Kayci Huff-Hardy
- Department of Internal Medicine, and Department of Molecular Biology, University of Texas Southwestern Medical Center, Dallas, TX, 75390, USA
| | - Lois Weisman
- Life Sciences Institute, University of Michigan, Ann Arbor, MI, 48109, USA
| | - Ezra Burstein
- Department of Internal Medicine, and Department of Molecular Biology, University of Texas Southwestern Medical Center, Dallas, TX, 75390, USA.
| | - Daniel D Billadeau
- Division of Oncology Research and Department of Biochemistry and Molecular Biology, College of Medicine, Mayo Clinic, Rochester, MN, 55905, USA.
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17
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Kano F, Murata M. Phosphatidylinositol-3-phosphate-mediated actin domain formation linked to DNA synthesis upon insulin treatment in rat hepatoma-derived H4IIEC3 cells. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2019; 1866:793-805. [PMID: 30742930 DOI: 10.1016/j.bbamcr.2019.02.005] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/18/2018] [Revised: 02/04/2019] [Accepted: 02/07/2019] [Indexed: 01/20/2023]
Abstract
Phosphatidylinositol-3-phosphate (PI3P) is a lipid that accumulates in the early endosomal membrane, and acts as a scaffold to recruit proteins that contain a PI3P-binding domain, such as the FYVE domain. In this study, we examined the effect of PI3P depletion on the insulin response in rat hepatoma-derived H4IIEC3 cells. We found that insulin treatment induced the transient formation of an actin domain structure, a mesh-like tangled network of actin filaments where phosphorylated Akt, endosomal proteins, and PI3P accumulated. Actin domain formation was repressed by the depletion of PI3P by SAR405, an inhibitor of the class III PI3 kinase, Vps34, by the inhibition of PI3P function by the competitive binding of an excess amount of GST-fused 2xFYVE protein to intracellular PI3P, and by the use of diabetic model cells, in which PI3P was depleted. SAR405 did not affect the phosphorylation level of Akt, and the transcriptional regulation of gluconeogenic and cholesterol synthetic genes after insulin treatment. Interestingly, insulin-induced DNA synthesis was specifically inhibited by SAR405, cytochalasin B, and also in diabetic model cells. These results suggest that PI3P is required for the formation of actin domains, which affected a signaling pathway downstream of Akt associated with DNA synthesis in H4IIEC3 cells.
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Affiliation(s)
- Fumi Kano
- Cell Biology Center, Institute of Innovative Research, Tokyo Institute of Technology, 4259 Nagatsuta, Midori-ku, Yokohama, Kanagawa 226-8503, Japan; Laboratory of Frontier Image Analysis, Graduate School of Arts and Sciences, The University of Tokyo, 3-8-1 Komaba, Meguro-ku, Tokyo 153-8902, Japan.
| | - Masayuki Murata
- Cell Biology Center, Institute of Innovative Research, Tokyo Institute of Technology, 4259 Nagatsuta, Midori-ku, Yokohama, Kanagawa 226-8503, Japan; Laboratory of Frontier Image Analysis, Graduate School of Arts and Sciences, The University of Tokyo, 3-8-1 Komaba, Meguro-ku, Tokyo 153-8902, Japan; Department of Life Sciences, Graduate School of Arts and Sciences, The University of Tokyo, 3-8-1 Komaba, Meguro-ku, Tokyo 153-8902, Japan.
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18
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Hu X, Mullins RD. LC3 and STRAP regulate actin filament assembly by JMY during autophagosome formation. J Cell Biol 2019; 218:251-266. [PMID: 30420355 PMCID: PMC6314544 DOI: 10.1083/jcb.201802157] [Citation(s) in RCA: 34] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2018] [Revised: 08/31/2018] [Accepted: 10/09/2018] [Indexed: 01/22/2023] Open
Abstract
During autophagy, actin filament networks move and remodel cellular membranes to form autophagosomes that enclose and metabolize cytoplasmic contents. Two actin regulators, WHAMM and JMY, participate in autophagosome formation, but the signals linking autophagy to actin assembly are poorly understood. We show that, in nonstarved cells, cytoplasmic JMY colocalizes with STRAP, a regulator of JMY's nuclear functions, on nonmotile vesicles with no associated actin networks. Upon starvation, JMY shifts to motile, LC3-containing membranes that move on actin comet tails. LC3 enhances JMY's de novo actin nucleation activity via a cryptic actin-binding sequence near JMY's N terminus, and STRAP inhibits JMY's ability to nucleate actin and activate the Arp2/3 complex. Cytoplasmic STRAP negatively regulates autophagy. Finally, we use purified proteins to reconstitute LC3- and JMY-dependent actin network formation on membranes and inhibition of network formation by STRAP. We conclude that LC3 and STRAP regulate JMY's actin assembly activities in trans during autophagy.
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Affiliation(s)
- Xiaohua Hu
- Department of Cellular and Molecular Pharmacology, University of California, San Francisco, School of Medicine, San Francisco, CA
- Howard Hughes Medical Institute, Chevy Chase, MD
| | - R Dyche Mullins
- Department of Cellular and Molecular Pharmacology, University of California, San Francisco, School of Medicine, San Francisco, CA
- Howard Hughes Medical Institute, Chevy Chase, MD
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19
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Osinalde N, Duarri A, Ramirez J, Barrio R, Perez de Nanclares G, Mayor U. Impaired proteostasis in rare neurological diseases. Semin Cell Dev Biol 2018; 93:164-177. [PMID: 30355526 DOI: 10.1016/j.semcdb.2018.10.007] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2018] [Revised: 10/09/2018] [Accepted: 10/16/2018] [Indexed: 12/19/2022]
Abstract
Rare diseases are classified as such when their prevalence is 1:2000 or lower, but even if each of them is so infrequent, altogether more than 300 million people in the world suffer one of the ∼7000 diseases considered as rare. Over 1200 of these disorders are known to affect the brain or other parts of our nervous system, and their symptoms can affect cognition, motor function and/or social interaction of the patients; we refer collectively to them as rare neurological disorders or RNDs. We have focused this review on RNDs known to have compromised protein homeostasis pathways. Proteostasis can be regulated and/or altered by a chain of cellular mechanisms, from protein synthesis and folding, to aggregation and degradation. Overall, we provide a list comprised of above 215 genes responsible for causing more than 170 distinct RNDs, deepening on some representative diseases, including as well a clinical view of how those diseases are diagnosed and dealt with. Additionally, we review existing methodologies for diagnosis and treatment, discussing the potential of specific deubiquitinating enzyme inhibition as a future therapeutic avenue for RNDs.
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Affiliation(s)
- Nerea Osinalde
- Department of Biochemistry and Molecular Biology, Faculty of Pharmacy, University of the Basque Country (UPV/EHU), 01006 Vitoria-Gasteiz, Spain
| | - Anna Duarri
- Barcelona Stem Cell Bank, Center of Regenerative Medicine in Barcelona, 08908 Hospitalet de Llobregat, Barcelona, Spain
| | - Juanma Ramirez
- Department of Biochemistry and Molecular Biology, Faculty of Science and Technology, University of the Basque Country (UPV/EHU), 48940 Leioa, Spain
| | - Rosa Barrio
- Functional Genomics Unit, CIC bioGUNE, 48160 Derio, Spain
| | - Guiomar Perez de Nanclares
- Molecular (Epi)Genetics Laboratory, BioAraba National Health Institute, Hospital Universitario Araba-Txagorritxu, Vitoria-Gasteiz, Alava, Spain
| | - Ugo Mayor
- Department of Biochemistry and Molecular Biology, Faculty of Science and Technology, University of the Basque Country (UPV/EHU), 48940 Leioa, Spain; Ikerbasque, Basque Foundation for Science, 48013 Bilbao, Spain.
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20
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Hyun HS, Kim SH, Park E, Cho MH, Kang HG, Lee HS, Miyake N, Matsumoto N, Tsukaguchi H, Cheong HI. A familial case of Galloway-Mowat syndrome due to a novel TP53RK mutation: a case report. BMC MEDICAL GENETICS 2018; 19:131. [PMID: 30053862 PMCID: PMC6063015 DOI: 10.1186/s12881-018-0649-y] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/02/2018] [Accepted: 07/20/2018] [Indexed: 12/12/2022]
Abstract
BACKGROUND Galloway-Mowat syndrome (GAMOS) is a rare hereditary renal-neurological disease characterized by early-onset steroid-resistant nephrotic syndrome in combination with microcephaly and brain anomalies. Recently, novel causative mutations for this disease have been identified in the genes encoding the four KEOPS subunits: OSGEP, TP53RK, TPRKB, and LAGE3. CASE PRESENTATION We detected a novel homozygous TP53RK mutation (NM_033550, c.194A > T, p.Lys65Met) using whole exome sequencing in a familial case of GAMOS with three affected siblings. All three patients manifested similar phenotypes, including very early-onset nephrotic syndrome (8 days, 1 day, and 1 day after birth, respectively), microcephaly, dysmorphic faces, and early fatality (10 months, 21 days, and 25 days of age, respectively). One patient also showed hiatal hernia with gastric volvulus. Renal biopsy performed on one patient revealed focal segmental glomerulosclerosis with severe tubulo-interstitial changes. CONCLUSION We report on a familial case of GAMOS with three affected siblings carrying a novel homozygous TP53RK mutation. To our knowledge, this is only the second report on GAMOS in association with a TP53RK mutation.
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Affiliation(s)
- Hye Sun Hyun
- Department of Pediatrics, Seoul National University Children's Hospital, 101 Daehak-Ro, Jongno-Gu, Seoul, 03080, South Korea
| | - Seong Heon Kim
- Department of Pediatrics, Pusan National University Children's Hospital, Yangsan, South Korea
| | - Eujin Park
- Department of Pediatrics, Seoul National University Children's Hospital, 101 Daehak-Ro, Jongno-Gu, Seoul, 03080, South Korea
| | - Myung Hyun Cho
- Department of Pediatrics, Seoul National University Children's Hospital, 101 Daehak-Ro, Jongno-Gu, Seoul, 03080, South Korea
| | - Hee Gyung Kang
- Department of Pediatrics, Seoul National University Children's Hospital, 101 Daehak-Ro, Jongno-Gu, Seoul, 03080, South Korea.,Research Coordination Center for Rare Diseases, Seoul National University Hospital, Seoul, South Korea
| | - Hyun Soon Lee
- Renal Pathology Lab, Hankook Kidney and Diabetes Institute, Seoul, South Korea
| | - Noriko Miyake
- Department of Human Genetics, Yokohama City University Graduate School of Medicine, Yokohama, Japan
| | - Naomichi Matsumoto
- Department of Human Genetics, Yokohama City University Graduate School of Medicine, Yokohama, Japan
| | - Hiroyasu Tsukaguchi
- Second Department of Internal Medicine, Kansai Medical University, Osaka, Japan
| | - Hae Il Cheong
- Department of Pediatrics, Seoul National University Children's Hospital, 101 Daehak-Ro, Jongno-Gu, Seoul, 03080, South Korea. .,Department of Pediatrics, Seoul National University College of Medicine, Seoul, South Korea. .,Kidney Research Institute, Medical Research Center, Seoul National University College of Medicine, Seoul, South Korea.
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Actin Cross-Linking Toxin Is a Universal Inhibitor of Tandem-Organized and Oligomeric G-Actin Binding Proteins. Curr Biol 2018; 28:1536-1547.e9. [PMID: 29731300 DOI: 10.1016/j.cub.2018.03.065] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2017] [Revised: 03/06/2018] [Accepted: 03/28/2018] [Indexed: 11/20/2022]
Abstract
Delivery of bacterial toxins to host cells is hindered by host protective barriers. This obstruction dictates a remarkable efficiency of toxins, a single copy of which may kill a host cell. Efficiency of actin-targeting toxins is further hampered by an overwhelming abundance of their target. The actin cross-linking domain (ACD) toxins of Vibrio species and related bacterial genera catalyze the formation of covalently cross-linked actin oligomers. Recently, we reported that the ACD toxicity can be amplified via a multivalent inhibitory association of actin oligomers with actin assembly factors formins, suggesting that the oligomers may act as secondary toxins. Importantly, many proteins involved in nucleation, elongation, severing, branching, and bundling of actin filaments contain G-actin-binding Wiskott-Aldrich syndrome protein (WASP)-homology motifs 2 (WH2) organized in tandem and therefore may act as a multivalent platform for high-affinity interaction with the ACD-cross-linked actin oligomers. Using live-cell single-molecule speckle (SiMS) microscopy, total internal reflection fluorescence (TIRF) microscopy, and actin polymerization assays, we show that, in addition to formins, the oligomers bind with high affinity and potently inhibit several families of actin assembly factors: Ena/vasodilator-stimulated phosphorprotein (VASP); Spire; and the Arp2/3 complex, both in vitro and in live cells. As a result, ACD blocks the actin retrograde flow and membrane dynamics and disrupts association of Ena/VASP with adhesion complexes. This study defines ACD as a universal inhibitor of tandem-organized G-actin binding proteins that overcomes the abundance of actin by redirecting the toxicity cascade toward less abundant targets and thus leading to profound disorganization of the actin cytoskeleton and disruption of actin-dependent cellular functions.
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