1
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Jacques M, Landen S, Romero JA, Hiam D, Schittenhelm RB, Hanchapola I, Shah AD, Voisin S, Eynon N. Methylome and proteome integration in human skeletal muscle uncover group and individual responses to high-intensity interval training. FASEB J 2023; 37:e23184. [PMID: 37698381 DOI: 10.1096/fj.202300840rr] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2023] [Revised: 08/17/2023] [Accepted: 08/24/2023] [Indexed: 09/13/2023]
Abstract
Exercise is a major beneficial contributor to muscle metabolism, and health benefits acquired by exercise are a result of molecular shifts occurring across multiple molecular layers (i.e., epigenome, transcriptome, and proteome). Identifying robust, across-molecular level targets associated with exercise response, at both group and individual levels, is paramount to develop health guidelines and targeted health interventions. Sixteen, apparently healthy, moderately trained (VO2 max = 51.0 ± 10.6 mL min-1 kg-1 ) males (age range = 18-45 years) from the Gene SMART (Skeletal Muscle Adaptive Responses to Training) study completed a longitudinal study composed of 12-week high-intensity interval training (HIIT) intervention. Vastus lateralis muscle biopsies were collected at baseline and after 4, 8, and 12 weeks of HIIT. DNA methylation (~850 CpG sites) and proteomic (~3000 proteins) analyses were conducted at all time points. Mixed models were applied to estimate group and individual changes, and methylome and proteome integration was conducted using a holistic multilevel approach with the mixOmics package. A total of 461 proteins significantly changed over time (at 4, 8, and 12 weeks), whilst methylome overall shifted with training only one differentially methylated position (DMP) was significant (adj.p-value < .05). K-means analysis revealed cumulative protein changes by clusters of proteins that presented similar changes over time. Individual responses to training were observed in 101 proteins. Seven proteins had large effect-sizes >0.5, among them are two novel exercise-related proteins, LYRM7 and EPN1. Integration analysis showed bidirectional relationships between the methylome and proteome. We showed a significant influence of HIIT on the epigenome and more so on the proteome in human muscle, and uncovered groups of proteins clustering according to similar patterns across the exercise intervention. Individual responses to exercise were observed in the proteome with novel mitochondrial and metabolic proteins consistently changed across individuals. Future work is required to elucidate the role of these proteins in response to exercise.
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Affiliation(s)
- Macsue Jacques
- Institute for Health and Sport (iHeS), Victoria University, Melbourne, Victoria, Australia
| | - Shanie Landen
- Institute for Health and Sport (iHeS), Victoria University, Melbourne, Victoria, Australia
| | - Javier Alvarez Romero
- Institute for Health and Sport (iHeS), Victoria University, Melbourne, Victoria, Australia
| | - Danielle Hiam
- Institute for Health and Sport (iHeS), Victoria University, Melbourne, Victoria, Australia
- Institute of Nutrition and Health Sciences, Deakin University, Melbourne, Victoria, Australia
| | - Ralf B Schittenhelm
- Monash Proteomics & Metabolomics Facility, Monash University, Melbourne, Victoria, Australia
| | - Iresha Hanchapola
- Monash Proteomics & Metabolomics Facility, Monash University, Melbourne, Victoria, Australia
| | - Anup D Shah
- Monash Proteomics & Metabolomics Facility, Monash University, Melbourne, Victoria, Australia
| | - Sarah Voisin
- Institute for Health and Sport (iHeS), Victoria University, Melbourne, Victoria, Australia
- Novo Nordisk Foundation Center for Basic Metabolic Research, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Nir Eynon
- Institute for Health and Sport (iHeS), Victoria University, Melbourne, Victoria, Australia
- Australian Regenerative Medicine Institute, Monash University, Melbourne, Victoria, Australia
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2
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Wu Y, Lv X, Wang H, Qian K, Ding J, Wang J, Hua S, Sun T, Zhou Y, Yu L, Qiu S. Adaptor protein APPL1 links neuronal activity to chromatin remodeling in cultured hippocampal neurons. J Mol Cell Biol 2021; 13:335-346. [PMID: 33104190 PMCID: PMC8373263 DOI: 10.1093/jmcb/mjaa058] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2020] [Revised: 07/29/2020] [Accepted: 08/25/2020] [Indexed: 11/15/2022] Open
Abstract
Local signaling events at synapses or axon terminals are communicated to the nucleus to elicit transcriptional responses, and thereby translate information about the external environment into internal neuronal representations. This retrograde signaling is critical to dendritic growth, synapse development, and neuronal plasticity. Here, we demonstrate that neuronal activity induces retrograde translocation and nuclear accumulation of endosomal adaptor APPL1. Disrupting the interaction of APPL1 with Importin α1 abolishes nuclear accumulation of APPL1, which in turn decreases the levels of histone acetylation. We further demonstrate that retrograde translocation of APPL1 is required for the regulation of gene transcription and then maintenance of hippocampal late-phase long-term potentiation. Thus, these results illustrate an APPL1-mediated pathway that contributes to the modulation of synaptic plasticity via coupling neuronal activity with chromatin remodeling.
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Affiliation(s)
- Yu Wu
- Department of Neurobiology, Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou 310058, China.,Department of Anesthesiology, Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou 310058, China
| | - Xinyou Lv
- Department of Neurobiology, Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou 310058, China.,Department of Anesthesiology, Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou 310058, China
| | - Haiting Wang
- Department of Neurobiology, Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou 310058, China.,Department of Anesthesiology, Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou 310058, China
| | - Kai Qian
- Department of Neurobiology, Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou 310058, China.,Department of Anesthesiology, Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou 310058, China
| | - Jinjun Ding
- Department of Neurobiology, Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou 310058, China.,Department of Anesthesiology, Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou 310058, China
| | - Jiejie Wang
- Department of Neurobiology, Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou 310058, China.,Department of Anesthesiology, Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou 310058, China
| | - Shushan Hua
- Department of Neurobiology, Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou 310058, China.,Department of Anesthesiology, Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou 310058, China
| | - Tiancheng Sun
- Department of Neurobiology, Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou 310058, China.,Department of Anesthesiology, Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou 310058, China
| | - Yiting Zhou
- Department of Biochemistry, Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou 310058, China.,Department of Orthopaedic Surgery, Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou 310058, China
| | - Lina Yu
- Department of Neurobiology, Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou 310058, China.,Department of Anesthesiology, Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou 310058, China
| | - Shuang Qiu
- Department of Neurobiology, Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou 310058, China.,Department of Anesthesiology, Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou 310058, China.,NHC and CAMS Key Laboratory of Medical Neurobiology, MOE Frontier Science Center for Brain Research and Brain-Machine Integration, School of Brain Science and Brain Medicine, Zhejiang University, Hangzhou 310058, China
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Tsai CC, Kuo FT, Lee SB, Chang YT, Fu HW. Endocytosis-dependent lysosomal degradation of Src induced by protease-activated receptor 1. FEBS Lett 2019; 593:504-517. [PMID: 30758841 DOI: 10.1002/1873-3468.13336] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2018] [Revised: 01/28/2019] [Accepted: 02/07/2019] [Indexed: 11/08/2022]
Abstract
Src plays a critical role in regulating cellular responses induced by protease-activated receptor 1 (PAR1). Here, we found that PAR1 activation induces lysosomal degradation of Src. Src is associated and trafficked together with activated PAR1 to early endosomes and then sorted to lysosomes for degradation. Blocking agonist-induced endocytosis of PAR1 by inhibition of dynamin activity suppresses PAR1-induced degradation of Src. However, Src activity is neither required for agonist-induced PAR1 internalization nor required for Src degradation upon PAR1 activation. We show that PAR1 activation triggers endocytosis-dependent lysosomal degradation of Src in both human embryonic kidney 293 and human umbilical vein endothelial cells. Our finding provides a new paradigm for how an irreversibly activated receptor regulates its downstream signalling.
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Affiliation(s)
- Chung-Che Tsai
- Institute of Molecular and Cellular Biology, National Tsing Hua University, Hsinchu, Taiwan, Republic of China
| | - Fang-Ting Kuo
- Institute of Molecular and Cellular Biology, National Tsing Hua University, Hsinchu, Taiwan, Republic of China
| | - Sung-Bau Lee
- Department of Life Science, National Tsing Hua University, Hsinchu, Taiwan, Republic of China.,College of Pharmacy, Taipei Medical University, Taiwan, Republic of China
| | - Yu-Ting Chang
- Institute of Molecular and Cellular Biology, National Tsing Hua University, Hsinchu, Taiwan, Republic of China
| | - Hua-Wen Fu
- Institute of Molecular and Cellular Biology, National Tsing Hua University, Hsinchu, Taiwan, Republic of China.,Department of Life Science, National Tsing Hua University, Hsinchu, Taiwan, Republic of China
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4
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A Novel β-adaptin/c-Myc Complex Formation Modulated by Oxidative Stress in the Control of the Cell Cycle in Macrophages and its Implication in Atherogenesis. Sci Rep 2017; 7:13442. [PMID: 29044181 PMCID: PMC5647411 DOI: 10.1038/s41598-017-13880-5] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2017] [Accepted: 10/02/2017] [Indexed: 02/07/2023] Open
Abstract
Our study tested the proposal that c-Myc activation in macrophages is differentially carried out dependent on the intracellular oxidative state of cells and potentially associated to the process of atherogenesis. Under our experimental conditions, the generation of reactive oxygen species carried out by the presence of oxidized low density lipoproteins (oxLDL) or Gram negative bacterial lipopolysaccharides (LPS) modifies the expression of cellular adhesion molecules such as c-Abl, calcium transport proteins such as the plasma membrane Ca2+-ATPase (PMCA), CD47, procaspase-7, CASP7, CHOP, transcriptional activators such as c-Jun and c-Myc and molecules that participate in the process of endocytosis like α- and β-adaptin. We present the first evidence showing that a state of oxidative stress alters c-Myc-dependent activity pathways in macrophages through binding to molecules such as β-adaptin promoting the reversible formation of a complex that presents the ability to regulate the development of the cell cycle. We propose that the subtle regulation carried out through the formation of this c-Myc/β-adaptin complex when cells change from a normal physiological condition to a state of oxidative stress, represents a defense mechanism against the deleterious effects caused by the loss of cell homeostasis.
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Szymanska E, Budick-Harmelin N, Miaczynska M. Endosomal "sort" of signaling control: The role of ESCRT machinery in regulation of receptor-mediated signaling pathways. Semin Cell Dev Biol 2017; 74:11-20. [PMID: 28797837 DOI: 10.1016/j.semcdb.2017.08.012] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2017] [Revised: 07/24/2017] [Accepted: 08/04/2017] [Indexed: 12/31/2022]
Abstract
The endosomal sorting complexes required for transport (ESCRTs) machinery consists of four protein assemblies (ESCRT-0 to -III subcomplexes) which mediate various processes of membrane remodeling in the cell. In the endocytic pathway, ESCRTs sort cargo destined for degradation into intraluminal vesicles (ILVs) of endosomes. Cargos targeted by ESCRTs include various signaling molecules, mainly internalized cell-surface receptors but also some cytosolic proteins. It is therefore expected that aberrant trafficking caused by ESCRT dysfunction affects different signaling pathways. Here we review how perturbation of ESCRT activity alters intracellular transport of membrane receptors, causing their accumulation on endocytic compartments, decreased degradation and/or altered recycling to the plasma membrane. We further describe how perturbed trafficking of receptors impacts the activity of their downstream signaling pathways, with or without changes in transcriptional responses. Finally, we present evidence that ESCRT components can also control activity and intracellular distribution of cytosolic signaling proteins (kinases, other effectors and soluble receptors). The underlying mechanisms involve sequestration of such proteins in ILVs, their sorting for degradation or towards non-lysosomal destinations, and regulating their availability in various cellular compartments. All these ESCRT-mediated processes can modulate final outputs of multiple signaling pathways.
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Affiliation(s)
- Ewelina Szymanska
- Laboratory of Cell Biology, International Institute of Molecular and Cell Biology, Warsaw, Poland
| | - Noga Budick-Harmelin
- Laboratory of Cell Biology, International Institute of Molecular and Cell Biology, Warsaw, Poland; Cell Research and Immunology Department, George S. Wise Faculty of Life Sciences, Tel Aviv University, Israel
| | - Marta Miaczynska
- Laboratory of Cell Biology, International Institute of Molecular and Cell Biology, Warsaw, Poland.
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6
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Radulovic M, Baqader NO, Stoeber K, Godovac-Zimmermann J. Spatial Cross-Talk between Oxidative Stress and DNA Replication in Human Fibroblasts. J Proteome Res 2016; 15:1907-38. [PMID: 27142241 DOI: 10.1021/acs.jproteome.6b00101] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
MS-based proteomics has been applied to a differential network analysis of the nuclear-cytoplasmic subcellular distribution of proteins between cell-cycle arrest: (a) at the origin activation checkpoint for DNA replication, or (b) in response to oxidative stress. Significant changes were identified for 401 proteins. Cellular response combines changes in trafficking and in total abundance to vary the local compartmental abundances that are the basis of cellular response. Appreciable changes for both perturbations were observed for 245 proteins, but cross-talk between oxidative stress and DNA replication is dominated by 49 proteins that show strong changes for both. Many nuclear processes are influenced by a spatial switch involving the proteins {KPNA2, KPNB1, PCNA, PTMA, SET} and heme/iron proteins HMOX1 and FTH1. Dynamic spatial distribution data are presented for proteins involved in caveolae, extracellular matrix remodelling, TGFβ signaling, IGF pathways, emerin complexes, mitochondrial protein import complexes, spliceosomes, proteasomes, and so on. The data indicate that for spatially heterogeneous cells cross-compartmental communication is integral to their system biology, that coordinated spatial redistribution for crucial protein networks underlies many functional changes, and that information on dynamic spatial redistribution of proteins is essential to obtain comprehensive pictures of cellular function. We describe how spatial data of the type presented here can provide priorities for further investigation of crucial features of high-level spatial coordination across cells. We suggest that the present data are related to increasing indications that much of subcellular protein transport is constitutive and that perturbation of these constitutive transport processes may be related to cancer and other diseases. A quantitative, spatially resolved nucleus-cytoplasm interaction network is provided for further investigations.
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Affiliation(s)
- Marko Radulovic
- Division of Medicine, University College London, Center for Nephrology , Royal Free Campus, Rowland Hill Street, London NW3 2PF, United Kingdom.,Insitute of Oncology and Radiology , Pasterova 14, 11000 Belgrade, Serbia
| | - Noor O Baqader
- Division of Medicine, University College London, Center for Nephrology , Royal Free Campus, Rowland Hill Street, London NW3 2PF, United Kingdom
| | - Kai Stoeber
- Research Department of Pathology and UCL Cancer Institute, Rockefeller Building, University College London , University Street, London WC1E 6JJ, United Kingdom
| | - Jasminka Godovac-Zimmermann
- Division of Medicine, University College London, Center for Nephrology , Royal Free Campus, Rowland Hill Street, London NW3 2PF, United Kingdom
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7
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Vásquez-Soto B, Manríquez N, Cruz-Amaya M, Zouhar J, Raikhel NV, Norambuena L. Sortin2 enhances endocytic trafficking towards the vacuole in Saccharomyces cerevisiae. Biol Res 2015. [PMID: 26209329 PMCID: PMC4515019 DOI: 10.1186/s40659-015-0032-9] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023] Open
Abstract
BACKGROUND A highly regulated trafficking of cargo vesicles in eukaryotes performs protein delivery to a variety of cellular compartments of endomembrane system. The two main routes, the secretory and the endocytic pathways have pivotal functions in uni- and multi-cellular organisms. Protein delivery and targeting includes cargo recognition, vesicle formation and fusion. Developing new tools to modulate protein trafficking allows better understanding the endomembrane system mechanisms and their regulation. The compound Sortin2 has been described as a protein trafficking modulator affecting targeting of the vacuolar protein carboxypeptidase Y (CPY), triggering its secretion in Saccharomyces cerevisiae. RESULTS A reverse chemical-genetics approach was used to identify key proteins for Sortin2 bioactivity. A genome-wide Sortin2 resistance screen revealed six yeast deletion mutants that do not secrete CPY when grown at Sortin2 condition where the parental strain does: met18, sla1, clc1, dfg10, dpl1 and yjl175w. Integrating mutant phenotype and gene ontology annotation of the corresponding genes and their interactome pointed towards a high representation of genes involved in the endocytic process. In wild type yeast endocytosis towards the vacuole was faster in presence of Sortin2, which further validates the data of the genome-wide screen. This effect of Sortin2 depends on structural features of the molecule, suggesting compound specificity. Sortin2 did not affect endocytic trafficking in Sortin2-resistant mutants, strongly suggesting that the Sortin2 effects on the secretory and endocytic pathways are linked. CONCLUSIONS Overall, the results reveal that Sortin2 enhances the endocytic transport pathway in Saccharomyces cerevisiae. This cellular effect is most likely at the level where secretory and endocytic pathways are merged. Them Sortin2 specificity over the endomembrane system places it as a powerful biological modulator for cell biology.
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Affiliation(s)
- Beatriz Vásquez-Soto
- Plant Molecular Biology Centre, Department of Biology, Faculty of Sciences, University of Chile, Las Palmeras 3425 Ñuñoa, Santiago, Chile.
| | - Nicolás Manríquez
- Plant Molecular Biology Centre, Department of Biology, Faculty of Sciences, University of Chile, Las Palmeras 3425 Ñuñoa, Santiago, Chile.
| | - Mirna Cruz-Amaya
- Plant Molecular Biology Centre, Department of Biology, Faculty of Sciences, University of Chile, Las Palmeras 3425 Ñuñoa, Santiago, Chile.
| | - Jan Zouhar
- Centro de Biotecnología y Genómica de Plantas, Universidad Politécnica de Madrid, Madrid, Spain.
| | - Natasha V Raikhel
- Center for Plant Cell Biology, Department of Botany and Plant Sciences, University of California, Riverside, CA, 92521, USA.
| | - Lorena Norambuena
- Plant Molecular Biology Centre, Department of Biology, Faculty of Sciences, University of Chile, Las Palmeras 3425 Ñuñoa, Santiago, Chile.
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8
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Endocytic Adaptor Protein Tollip Inhibits Canonical Wnt Signaling. PLoS One 2015; 10:e0130818. [PMID: 26110841 PMCID: PMC4482507 DOI: 10.1371/journal.pone.0130818] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2014] [Accepted: 05/26/2015] [Indexed: 01/12/2023] Open
Abstract
Many adaptor proteins involved in endocytic cargo transport exhibit additional functions in other cellular processes which may be either related to or independent from their trafficking roles. The endosomal adaptor protein Tollip is an example of such a multitasking regulator, as it participates in trafficking and endosomal sorting of receptors, but also in interleukin/Toll/NF-κB signaling, bacterial entry, autophagic clearance of protein aggregates and regulation of sumoylation. Here we describe another role of Tollip in intracellular signaling. By performing a targeted RNAi screen of soluble endocytic proteins for their additional functions in canonical Wnt signaling, we identified Tollip as a potential negative regulator of this pathway in human cells. Depletion of Tollip potentiates the activity of β-catenin/TCF-dependent transcriptional reporter, while its overproduction inhibits the reporter activity and expression of Wnt target genes. These effects are independent of dynamin-mediated endocytosis, but require the ubiquitin-binding CUE domain of Tollip. In Wnt-stimulated cells, Tollip counteracts the activation of β-catenin and its nuclear accumulation, without affecting its total levels. Additionally, under conditions of ligand-independent signaling, Tollip inhibits the pathway after the stage of β-catenin stabilization, as observed in human cancer cell lines, characterized by constitutive β-catenin activity. Finally, the regulation of Wnt signaling by Tollip occurs also during early embryonic development of zebrafish. In summary, our data identify a novel function of Tollip in regulating the canonical Wnt pathway which is evolutionarily conserved between fish and humans. Tollip-mediated inhibition of Wnt signaling may contribute not only to embryonic development, but also to carcinogenesis. Mechanistically, Tollip can potentially coordinate multiple cellular pathways of trafficking and signaling, possibly by exploiting its ability to interact with ubiquitin and the sumoylation machinery.
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9
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Brodsky FM, Sosa RT, Ybe JA, O'Halloran TJ. Unconventional functions for clathrin, ESCRTs, and other endocytic regulators in the cytoskeleton, cell cycle, nucleus, and beyond: links to human disease. Cold Spring Harb Perspect Biol 2014; 6:a017004. [PMID: 25183831 DOI: 10.1101/cshperspect.a017004] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
The roles of clathrin, its regulators, and the ESCRT (endosomal sorting complex required for transport) proteins are well defined in endocytosis. These proteins can also participate in intracellular pathways that are independent of endocytosis and even independent of the membrane trafficking function of these proteins. These nonendocytic functions involve unconventional biochemical interactions for some endocytic regulators, but can also exploit known interactions for nonendocytic functions. The molecular basis for the involvement of endocytic regulators in unconventional functions that influence the cytoskeleton, cell cycle, signaling, and gene regulation are described here. Through these additional functions, endocytic regulators participate in pathways that affect infection, glucose metabolism, development, and cellular transformation, expanding their significance in human health and disease.
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Affiliation(s)
- Frances M Brodsky
- Department of Bioengineering and Therapeutic Sciences, Departments of Pharmaceutical Chemistry and Microbiology and Immunology, The G.W. Hooper Foundation, University of California, San Francisco, San Francisco, California 94143-0552
| | - R Thomas Sosa
- Department of Molecular Biosciences, Institute for Cellular and Molecular Biology, University of Texas, Austin, Texas 78712-1095
| | - Joel A Ybe
- Department of Molecular and Cellular Biochemistry, Indiana University, Bloomington, Indiana 47405
| | - Theresa J O'Halloran
- Department of Molecular Biosciences, Institute for Cellular and Molecular Biology, University of Texas, Austin, Texas 78712-1095
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10
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Wu J, Bakerink KJ, Evangelista ME, Thomas GH. Cytoplasmic capes are nuclear envelope intrusions that are enriched in endosomal proteins and depend upon βH-spectrin and Annexin B9. PLoS One 2014; 9:e93680. [PMID: 24705398 PMCID: PMC3976414 DOI: 10.1371/journal.pone.0093680] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2013] [Accepted: 03/07/2014] [Indexed: 11/18/2022] Open
Abstract
It is increasingly recognized that non-erythroid spectrins have roles remote from the plasma membrane, notably in endomembrane trafficking. The large spectrin isoform, βH, partners with Annexin B9 to modulate endosomal processing of internalized proteins. This modulation is focused on the early endosome through multivesicular body steps of endocytic processing and loss of either protein appears to cause a traffic jam before removal of ubiquitin at the multivesicular body. We previously reported that βH/Annexin B9 influenced EGF receptor signaling. While investigating this effect we noticed that mSptiz, the membrane bound precursor of the secreted EGF receptor ligand sSpitz, is located in striking intrusions of the nuclear membrane. Here we characterize these structures and identify them as ‘cytoplasmic capes’, which were previously identified in old ultrastructural studies and probably coincide with recently recognized sites of non-nuclear-pore RNA export. We show that cytoplasmic capes contain multiple endosomal markers and that their existence is dependent upon βH and Annexin B9. Diminution of these structures does not lead to a change in mSpitz processing. These results extend the endosomal influence of βH and its partner Annexin B9 to this unusual compartment at the nuclear envelope.
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Affiliation(s)
- Juan Wu
- Departments of Biology and of Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, Pennsylvania, United States of America
- School of Public Health, Harvard Medical School, Boston, Massachusetts, United States of America
| | - Katelyn J. Bakerink
- Departments of Biology and of Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, Pennsylvania, United States of America
| | - Meagan E. Evangelista
- Departments of Biology and of Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, Pennsylvania, United States of America
| | - Graham H. Thomas
- Departments of Biology and of Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, Pennsylvania, United States of America
- * E-mail:
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11
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Bar M, Schuster S, Leibman M, Ezer R, Avni A. The function of EHD2 in endocytosis and defense signaling is affected by SUMO. PLANT MOLECULAR BIOLOGY 2014; 84:509-18. [PMID: 24154852 DOI: 10.1007/s11103-013-0148-7] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/13/2013] [Accepted: 10/16/2013] [Indexed: 06/02/2023]
Abstract
Post-translational modification of target proteins by the small ubiquitin-like modifier protein (SUMO) regulates many cellular processes. SUMOylation has been shown to regulate cellular localization and function of a variety of proteins, in some cases affecting nuclear import or export. We have previously characterized two EHDs (EH domain containing proteins) in Arabidospis and showed their involvement in plant endocytosis. AtEHD2 has an inhibitory effect on endocytosis of transferrin, FM-4-64, and the leucine rich repeat receptor like protein LeEix2, an effect that requires and intact coiled-coil domain. Inhibition of endocytosis of LeEix2 by EHD2 is effective in inhibiting defense responses mediated by the LeEix2 receptor in response to its ligand EIX. In the present work we demonstrate that SUMOylation of EHD2 appears to be required for EHD2-induced inhibition of LeEix2 endocytosis. Indeed, we found that a mutant form of EHD2, possessing a defective SUMOylation site, has an increased nuclear abundance, can no longer be SUMOylated and is no longer effective in inhibiting LeEix2 endocytosis or defense signaling in response to EIX.
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Affiliation(s)
- Maya Bar
- Department of Molecular Biology and Ecology of Plants, Tel-Aviv University, 69978, Tel-Aviv, Israel
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12
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Abstract
EHD {EH [Eps15 (epidermal growth factor receptor substrate 15) homology]-domain-containing} proteins participate in several endocytic events, such as the internalization and the recycling processes. There are four EHD proteins in mammalian cells, EHD1–EHD4, each with diverse roles in the recycling pathway of endocytosis. EHD2 is a plasma-membrane-associated member of the EHD family that regulates internalization. Since several endocytic proteins have been shown to undergo nucleocytoplasmic shuttling and have been assigned roles in regulation of gene expression, we tested the possibility that EHD proteins also shuttle to the nucleus. Our results showed that, among the three EHD proteins (EHD1–EHD3) that were tested, only EHD2 accumulates in the nucleus under nuclear export inhibition treatment. Moreover, the presence of a NLS (nuclear localization signal) was essential for its entry into the nucleus. Nuclear exit of EHD2 depended partially on its NES (nuclear export signal). Elimination of a potential SUMOylation site in EHD2 resulted in a major accumulation of the protein in the nucleus, indicating the involvement of SUMOylation in the nuclear exit of EHD2. We confirmed the SUMOylation of EHD2 by employing co-immunoprecipitation and the yeast two-hybrid system. Using GAL4-based transactivation assay as well as a KLF7 (Krüppel-like factor 7)-dependent transcription assay of the p21WAF1/Cip1 [CDKN1A (cyclin-dependent kinase inhibitor 1A)] gene, we showed that EHD2 represses transcription. qRT-PCR (quantitative real-time PCR) of RNA from cells overexpressing EHD2 or of RNA from cells knocked down for EHD2 confirmed that EHD2 represses transcription of the p21WAF1/Cip1 gene.
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13
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Novel aspects of the apolipoprotein-E receptor family: regulation and functional role of their proteolytic processing. ACTA ACUST UNITED AC 2012. [DOI: 10.1007/s11515-011-1186-7] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
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14
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Samson M, Jung D. Intracellular trafficking and fate of chimeric adenovirus 5/F35 in human B lymphocytes. J Gene Med 2012; 13:451-61. [PMID: 21766397 DOI: 10.1002/jgm.1588] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
BACKGROUND Investigation of the molecular processes that control the development and function of lymphocytes is essential for our understanding of humoral immunity, as well as lymphocyte-associated pathogenesis. Adenovirus-mediated gene transfer provides a powerful tool for investigating these processes. However, we observed variation in transgene expression among normal human peripheral blood B lymphocytes from different donors and at distinct stages of differentiation. It is recognized that efficient gene transfer is highly dependent on the intracellular route by which the viruses travel within the host cell. Thus, we aimed to examine this aspect in the present study. METHODS We analyzed the binding, uptake, intracellular trafficking and fate of CY3-labelled Ad5/F35 vectors in lymphoid cell lines and primary B cells. Furthermore, we decreased protein synthesis levels and rapid endocytosis in a plasma cell line exhibiting a high level of protein synthesis activity and activated transcription and endocytosis in primary B cells, which are less active than plasma cells. RESULTS Major differences in intracellular trafficking pattern between B cells and plasma cell line U266 were identified that explain the observed divergence in transgene expression efficiency. Importantly, modification of the transcriptional or translational activity of U266 cells reverted the Ad5/F35 endocytic trafficking to that seen in B cells, with a loss of transgene expression, whereas activation of B cells with phorbol 12-myristate 13-acetate had the opposite effects. CONCLUSIONS Taken together, these results suggest that Ad5/F35 is more efficiently transduced in cells with a strong transcriptional activity as a result of differences in intracellular trafficking. This finding extends our current knowledge of the mechanisms of adenovirus-mediated gene transfer.
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15
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E G, Cao Y, Bhattacharya S, Dutta S, Wang E, Mukhopadhyay D. Endogenous vascular endothelial growth factor-A (VEGF-A) maintains endothelial cell homeostasis by regulating VEGF receptor-2 transcription. J Biol Chem 2011; 287:3029-41. [PMID: 22167188 DOI: 10.1074/jbc.m111.293985] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
Vascular endothelial growth factor A (VEGF-A) is one of the most important factors controlling angiogenesis. Although the functions of exogenous VEGF-A have been widely studied, the roles of endogenous VEGF-A remain unclear. Here we focused on the mechanistic functions of endogenous VEGF-A in endothelial cells. We found that it is complexed with VEGF receptor 2 (VEGFR-2) and maintains a basal expression level for VEGFR-2 and its downstream signaling activation. Endogenous VEGF-A also controls expression of key endothelial specific genes including VEGFR-2, Tie-2, and vascular endothelial cadherin. Of importance, endogenous VEGF-A differs from exogenous VEGF-A by regulating VEGFR-2 transcription through mediation of FoxC2 binding to the FOX:ETS motif, and the complex formed by endogenous VEGF-A with VEGFR-2 is localized within the EEA1 (early endosome antigen 1) endosomal compartment. Taken together, our results emphasize the importance of endogenous VEGF-A in endothelial cells by regulating key vascular proteins and maintaining the endothelial homeostasis.
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Affiliation(s)
- Guangqi E
- Department of Biochemistry and Molecular Biology, Mayo Clinic College of Medicine, Rochester, Minnesota 55905, USA
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16
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Cholbinski P, Jastrzebska Z, Wysocka-Kapcinska M, Plochocka D, Gornicka A, Hopper AK, Zoladek T. Yeast ubiquitin ligase Rsp5 contains nuclear localization and export signals. Eur J Cell Biol 2011; 90:834-43. [PMID: 21868125 PMCID: PMC3167943 DOI: 10.1016/j.ejcb.2011.06.008] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2011] [Revised: 06/07/2011] [Accepted: 06/15/2011] [Indexed: 01/25/2023] Open
Abstract
The Rsp5 ubiquitin ligase regulates numerous cellular processes. Rsp5 is mainly localized to the cytoplasm but nuclear localization was also reported. A potential nuclear export signal was tested for activity by using a GFP(2) reporter. The 687-LIGGIAEIDI-696 sequence located in the Hect domain was identified as a nuclear export signal active in a Crm1-dependent manner, and its importance for the localization of Rsp5 was documented by using fluorescence microscopy and a lacZ-based reporter system. Analysis of the cellular location of other Rsp5 fragments fused with GFP(2) indicated two independent potential nuclear localization signals, both located in the Hect domain. We also uncovered Rsp5 fragments that are important to targeting/tethering Rsp5 to various regions in the cytoplasm. The presented data indicate that Rsp5 ligase is a shuttling protein whose distribution within the cytoplasm and partitioning between cytoplasmic and nuclear locations is determined by a balance between the actions of several targeting sequences and domains.
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Affiliation(s)
- Piotr Cholbinski
- Institute of Biochemistry and Biophysics, Polish Academy of Sciences, Warsaw, Poland
| | - Zaneta Jastrzebska
- Institute of Biochemistry and Biophysics, Polish Academy of Sciences, Warsaw, Poland
| | | | - Danuta Plochocka
- Institute of Biochemistry and Biophysics, Polish Academy of Sciences, Warsaw, Poland
| | - Agnieszka Gornicka
- Institute of Biochemistry and Biophysics, Polish Academy of Sciences, Warsaw, Poland
| | | | - Teresa Zoladek
- Institute of Biochemistry and Biophysics, Polish Academy of Sciences, Warsaw, Poland
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17
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Abstract
It is becoming clear that intracellular signaling events are intimately linked with the membrane transport processes. In addition to the long known role of endocytosis in downregulating plasma membrane receptors, more recent data uncover several sophisticated modes by which endocytosis affects the type and duration of signals. Particularly striking are various roles of endocytic compartments as membrane platforms for compartmentalized assembly or sequestration of specific signaling complexes. Here we review some recent examples illustrating how endosomes may mediate ligand-stimulated apoptotic signaling and how multivesicular bodies affect Wnt signaling by regulated sequestration of signaling molecules or their secretion in exosomes. We also discuss evidence documenting the involvement of endocytic proteins in the regulation of p53 activity and stability, which suggests a possible cross-talk between endocytic processes and transcriptional responses.
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Affiliation(s)
- Anna Hupalowska
- International Institute of Molecular and Cell Biology, Laboratory of Cell Biology, 4 Ks. Trojdena Street, Warsaw, Poland
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18
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Anandharaj A, Yu JR, Park WY. Phosphorylation of threonine 190 is essential for nuclear localization and endocytosis of the FTS (Fused Toes Homolog) protein. Int J Biol Macromol 2011; 49:721-8. [PMID: 21777610 DOI: 10.1016/j.ijbiomac.2011.07.005] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2011] [Revised: 07/04/2011] [Accepted: 07/05/2011] [Indexed: 10/18/2022]
Abstract
Fused Toes Homolog (FTS) is a member of a group of proteins termed as E2 variants and this group of proteins lacks an active cysteine residue that is required for ubiquitin transfer. We have identified the expression of this protein in early neoplastic stages of cervical cancer and its translocation into nucleus from cytoplasm upon irradiation. Here we have reported that a threonine residue at position 190 is essential for its nucleocytoplasmic shuttling and function. Upon LMB treatment we found that FTS was located in the nucleus and it suggests that direct role of nuclear export signal (NES) is required for the binding to CRM1 and facilitates nuclear export. The threonine residue was phosphorylated and promoted the phosphorylation of EGFR, p38 and JNK facilitating vesicular trafficking of early to late endosomes. Mutational change of the threonine into alanine resulted in the cytoplasmic localization of FTS and failed to phosphorylate EGFR and its downstream effector proteins. In addition the mutation also reduced the number of early endosomes formed and also resulted in the clustering of late endosomes around the perinuclear region. These data suggest that threonine residue of FTS at position 190 is not only essential for its function but also for the formation, maturation and trafficking of early endosomes to late endosome/lysosome, as well as we speculate that FTS may function at a connection point in the vesicle tethering.
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Affiliation(s)
- Arunkumar Anandharaj
- Department of Radiation Oncology, Chungbuk National University College of Medicine, Cheongju, Republic of Korea
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19
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Endocytosis-independent function of clathrin heavy chain in the control of basal NF-κB activation. PLoS One 2011; 6:e17158. [PMID: 21364927 PMCID: PMC3045402 DOI: 10.1371/journal.pone.0017158] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2010] [Accepted: 01/24/2011] [Indexed: 12/11/2022] Open
Abstract
Background Nuclear factor-κB (NF-κB) is a transcription factor that regulates the transcription of genes involved in a variety of biological processes, including innate and adaptive immunity, stress responses and cell proliferation. Constitutive or excessive NF-κB activity has been associated with inflammatory disorders and higher risk of cancer. In contrast to the mechanisms controlling inducible activation, the regulation of basal NF-κB activation is not well understood. Here we test whether clathrin heavy chain (CHC) contributes to the regulation of basal NF-κB activity in epithelial cells. Methodology Using RNA interference to reduce endogenous CHC expression, we found that CHC is required to prevent constitutive activation of NF-κB and gene expression. Immunofluorescence staining showed constitutive nuclear localization of the NF-κB subunit p65 in absence of stimulation after CHC knockdown. Elevated basal p65 nuclear localization is caused by constitutive phosphorylation and degradation of inhibitor of NF-κB alpha (IκBα) through an IκB kinase α (IKKα)-dependent mechanism. The role of CHC in NF-κB signaling is functionally relevant as constitutive expression of the proinflammatory chemokine interleukin-8 (IL-8), whose expression is regulated by NF-κB, was found after CHC knockdown. Disruption of clathrin-mediated endocytosis by chemical inhibition or depletion of the μ2-subunit of the endocytosis adaptor protein AP-2, and knockdown of clathrin light chain a (CHLa), failed to induce constitutive NF-κB activation and IL-8 expression, showing that CHC acts on NF-κB independently of endocytosis and CLCa. Conclusions We conclude that CHC functions as a built-in molecular brake that ensures a tight control of basal NF-κB activation and gene expression in unstimulated cells. Furthermore, our data suggest a potential link between a defect in CHC expression and chronic inflammation disorder and cancer.
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20
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Montanini B, Levati E, Bolchi A, Kohler A, Morin E, Tisserant E, Martin F, Ottonello S. Genome-wide search and functional identification of transcription factors in the mycorrhizal fungus Tuber melanosporum. THE NEW PHYTOLOGIST 2011; 189:736-750. [PMID: 21058951 DOI: 10.1111/j.1469-8137.2010.03525.x] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
• Developmental transitions associated with the life cycle of plant-symbiotic fungi, such as the ascomycete Tuber melanosporum, are likely to require an extensive reprogramming of gene expression brought about by transcription factors (TFs). To date, little is known about the transcriptome alterations that accompany developmental shifts associated with symbiosis or fruiting body formation. • Taking advantage of the black truffle genome sequence, we used a bioinformatic approach, coupled with functional analysis in yeast and transcriptome profiling, to identify and catalogue T. melanosporum TFs, the so-called 'regulome'. • The T. melanosporum regulome contains 102 homologs of previously characterized TFs, 57 homologs of hypothetical TFs, and 42 putative TFs apparently unique to Tuber. The yeast screen allowed the functional discovery of four TFs and the validation of about one-fifth of the in silico predicted TFs. Truffle proteins apparently unrelated to transcription were also identified as potential transcriptional regulators, together with a number of plant TFs. • Twenty-nine TFs, some of which associated with particular developmental stages, were found to be up-regulated in ECMs or fruiting bodies. About one-quarter of these up-regulated TFs are expressed at surprisingly high levels, thus pointing to a striking functional specialization of the different stages of the Tuber life cycle.
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Affiliation(s)
- Barbara Montanini
- Department of Biochemistry and Molecular Biology, University of Parma, 43100 Parma, Italy
| | - Elisabetta Levati
- Department of Biochemistry and Molecular Biology, University of Parma, 43100 Parma, Italy
| | - Angelo Bolchi
- Department of Biochemistry and Molecular Biology, University of Parma, 43100 Parma, Italy
| | - Annegret Kohler
- Ecogenomics of Interactions Lab, UMR 'Interactions Arbres/Micro-Organismes', INRA-Nancy, 54280 Champenoux, France
| | - Emmanuelle Morin
- Ecogenomics of Interactions Lab, UMR 'Interactions Arbres/Micro-Organismes', INRA-Nancy, 54280 Champenoux, France
| | - Emilie Tisserant
- Ecogenomics of Interactions Lab, UMR 'Interactions Arbres/Micro-Organismes', INRA-Nancy, 54280 Champenoux, France
| | - Francis Martin
- Ecogenomics of Interactions Lab, UMR 'Interactions Arbres/Micro-Organismes', INRA-Nancy, 54280 Champenoux, France
| | - Simone Ottonello
- Department of Biochemistry and Molecular Biology, University of Parma, 43100 Parma, Italy
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21
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Lone M, Kungl T, Koper A, Bottenberg W, Kammerer R, Klein M, Sweeney ST, Auburn RP, O'Kane CJ, Prokop A. The nuclear protein Waharan is required for endosomal-lysosomal trafficking in Drosophila. J Cell Sci 2010; 123:2369-74. [PMID: 20551180 DOI: 10.1242/jcs.060582] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
Here we report Drosophila Waharan (Wah), a 170-kD predominantly nuclear protein with two potential human homologues, as a newly identified regulator of endosomal trafficking. Wah is required for neuromuscular-junction development and muscle integrity. In muscles, knockdown of Wah caused novel accumulations of tightly packed electron-dense tubules, which we termed 'sausage bodies'. Our data suggest that sausage bodies coincide with sites at which ubiquitylated proteins and a number of endosomal and lysosomal markers co-accumulate. Furthermore, loss of Wah function generated loss of the acidic LysoTracker compartment. Together with data demonstrating that Wah acts earlier in the trafficking pathway than the Escrt-III component Drosophila Shrb (snf7 in Schizosaccharomyces pombe), our results indicate that Wah is essential for endocytic trafficking at the late endosome. Highly unexpected phenotypes result from Wah knockdown, in that the distribution of ubiquitylated cargos and endolysosomal morphologies are affected despite Wah being a predominant nuclear protein. This finding suggests the existence of a relationship between nuclear functions and endolysosomal trafficking. Future studies of Wah function will give us insights into this interesting phenomenon.
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Affiliation(s)
- Mohiddin Lone
- Faculty of Life Sciences, The University of Manchester, Oxford Road, M13 9PT Manchester, UK
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22
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Matej R, Botond G, László L, Kopitar-Jerala N, Rusina R, Budka H, Kovacs GG. Increased neuronal Rab5 immunoreactive endosomes do not colocalize with TDP-43 in motor neuron disease. Exp Neurol 2010; 225:133-9. [PMID: 20558162 DOI: 10.1016/j.expneurol.2010.06.004] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2010] [Revised: 06/01/2010] [Accepted: 06/07/2010] [Indexed: 12/11/2022]
Abstract
Sporadic motor neuron disease (MND) is characterized by progressive degeneration of motor neurons and intraneuronal cytoplasmic translocation and deposition of the nuclear protein TDP-43. There is a paucity of data on the subcellular mechanisms of the nuclear-cytoplasmic trafficking of TDP-43, particularly about the precise role of the endosomal-lysosomal system (ELS). In the present study, using a neuron-specific morphometric approach, we examined the expression of the early endosomal marker Rab5 and lysosomal cathepsins B, D, F, and L as well as PAS-stained structures in the anterior horn cells in 11 individuals affected by sporadic MND and 5 age-matched controls. This was compared with the expression of ubiquitin, p62 and TDP-43 and its phosphorylated form. The principal finding was the increased expression of the endosomal marker Rab5 and lysosomal cathepsin D, and of PAS-positive structures in motor neurons of MND cases. Furthermore, the area-portion of Rab5 immunoreactivity correlated well with the intracellular accumulation of ubiquitin, p62 and (phosphorylated) TDP-43. However, double immunolabelling and immunogold electron microscopy excluded colocalization of phosphorylated TDP-43 with the ELS. These data contrast with observations on neuronal cytopathology in Alzheimer's or prion diseases where the disease-specific proteins are processed within endosomes, and suggest a distinct role of the ELS in MND.
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Affiliation(s)
- Radoslav Matej
- Institute of Neurology, Medical University of Vienna, Vienna, Austria
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23
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Haberman AS, Akbar MA, Ray S, Krämer H. Drosophila acinus encodes a novel regulator of endocytic and autophagic trafficking. Development 2010; 137:2157-66. [PMID: 20504956 DOI: 10.1242/dev.044230] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Endosomal trafficking affects many cellular pathways from cell signaling to metabolism, but little is known about how these effects are coordinated. In a genetic screen for mutants affecting endosomal trafficking, we identified Drosophila acinus (dacn; hook-like). Its mammalian homolog Acinus has been implicated in RNA processing and chromatin fragmentation during apoptosis. Loss-of-function analysis of dacn revealed two distinct functions. First, dacn is required for stabilization of early endosomes, thus modulating levels of Notch and Egfr signaling. Second, loss of dacn interferes with cellular starvation responses by inhibiting autophagosome maturation. By contrast, overexpression of dacn causes lethality due to enhanced autophagy. We show that this enhanced autophagy is independent of the Tor pathway. Taken together, our data show that dacn encodes a regulator of endosomal and autophagosomal dynamics, modulating developmental signaling and the cellular response to starvation.
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Affiliation(s)
- Adam S Haberman
- Department of Neuroscience, UT Southwestern Medical Center, Dallas, TX 75390-9111, USA
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24
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Wang YN, Yamaguchi H, Hsu JM, Hung MC. Nuclear trafficking of the epidermal growth factor receptor family membrane proteins. Oncogene 2010; 29:3997-4006. [PMID: 20473332 DOI: 10.1038/onc.2010.157] [Citation(s) in RCA: 168] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Multiple membrane-bound receptor tyrosine kinases (RTKs), such as the epidermal growth factor receptor (EGFR) and ErbB-2, have been reported to be localized in the nucleus, where emerging evidence suggests that they are involved in transcriptional regulation, cell proliferation, DNA repair and chemo- and radio-resistance. Recent studies have shown that endocytosis and endosomal sorting are involved in the nuclear transport of cell surface RTKs. However, the detailed mechanism by which the full-length receptors embedded in the endosomal membrane travel all the way from the cell surface to the early endosomes and pass through the nuclear pore complexes is unknown. This important area has been overlooked for decades, which has hindered progress in our understanding of nuclear RTKs' functions. Here, we discuss the putative mechanisms by which EGFR family RTKs are shuttled into the nucleus. Understanding the trafficking mechanisms as to how RTKs are transported from the cell surface to the nucleus will significantly contribute to understanding the functions of the nuclear RTKs.
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Affiliation(s)
- Y-N Wang
- Department of Molecular and Cellular Oncology, University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA
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25
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Mettlen M, Loerke D, Yarar D, Danuser G, Schmid SL. Cargo- and adaptor-specific mechanisms regulate clathrin-mediated endocytosis. ACTA ACUST UNITED AC 2010; 188:919-33. [PMID: 20231386 PMCID: PMC2845073 DOI: 10.1083/jcb.200908078] [Citation(s) in RCA: 123] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Clathrin-coated pit size and dynamic behavior varies with low density lipoprotein receptor (LDLR) expression levels in a manner dependent on the LDLR-specific adaptors, Dab2 and ARH. Clathrin-mediated endocytosis of surface receptors and their bound ligands (i.e., cargo) is highly regulated, including by the cargo itself. One of the possible sources of the observed heterogeneous dynamics of clathrin-coated pits (CCPs) might be the different cargo content. Consistent with this, we show that CCP size and dynamic behavior varies with low density lipoprotein receptor (LDLR) expression levels in a manner dependent on the LDLR-specific adaptors, Dab2 and ARH. In Dab2-mCherry–expressing cells, varying LDLR expression leads to a progressive increase in CCP size and to the appearance of nonterminal endocytic events. In LDLR and ARH-mCherry–expressing cells in addition to an increase in CCP size, turnover of abortive CCPs increases, and the rate of CCP maturation decreases. Altogether, our results underscore the highly dynamic and cargo-responsive nature of CCP assembly and suggest that the observed heterogeneity is, in part, related to compositional differences (e.g., cargo and adaptors) between CCPs.
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Affiliation(s)
- Marcel Mettlen
- Department of Cell Biology, The Scripps Research Institute, La Jolla, CA 92037, USA
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26
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The Sla2p/HIP1/HIP1R family: similar structure, similar function in endocytosis? Biochem Soc Trans 2010; 38:187-91. [DOI: 10.1042/bst0380187] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
HIP1 (huntingtin interacting protein 1) has two close relatives: HIP1R (HIP1-related) and yeast Sla2p. All three members of the family have a conserved domain structure, suggesting a common function. Over the past decade, a number of studies have characterized these proteins using a combination of biochemical, imaging, structural and genetic techniques. These studies provide valuable information on binding partners, structure and dynamics of HIP1/HIP1R/Sla2p. In general, all suggest a role in CME (clathrin-mediated endocytosis) for the three proteins, though some differences have emerged. In this mini-review we summarize the current views on the roles of these proteins, while emphasizing the unique attributes of each family member.
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27
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Banerjee M, Datta M, Majumder P, Mukhopadhyay D, Bhattacharyya NP. Transcription regulation of caspase-1 by R393 of HIPPI and its molecular partner HIP-1. Nucleic Acids Res 2009; 38:878-92. [PMID: 19934260 PMCID: PMC2817453 DOI: 10.1093/nar/gkp1011] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Earlier we have shown that exogenous expression of HIPPI, a molecular partner of Huntingtin interacting protein HIP-1, induces apoptosis and increases expression of caspases-1, -8 and -10 in HeLa and Neuro2A cells. The C-terminal pseudo death effector domain of HIPPI (pDED-HIPPI) specifically interacts with the putative promoter sequences of these genes. In the present manuscript, we predict from structural modeling of pDED-HIPPI that R393 of HIPPI is important for such interaction. R393E mutation in pDED-HIPPI decreases the interaction with the putative promoter of caspase-1 in cells. Expression of caspase-1 is decreased in cells expressing mutant pDED-HIPPI in comparison to that observed in cells expressing wild type pDED-HIPPI. Using HIP-1 knocked down cells as well as over expressing HIP-1 with mutation at its nuclear localization signal and other deletion mutations, we demonstrate that translocation of HIPPI to the nucleus is mediated by HIP-1 for the increased expression of caspase-1. HIPPI-HIP-1 heterodimer is detected in cytoplasm as well as in the nucleus and is associated with transcription complex in cells. Taking together, we are able to show the importance of R393 of HIPPI and the role of HIPPI-HIP-1 heterodimer in the transcription regulation of caspase-1.
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Affiliation(s)
- M Banerjee
- Saha Institute of Nuclear Physics, 1/AF Bidhan Nagar, Kolkata 700 064, India
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28
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Functional characterization of the interactions between endosomal adaptor protein APPL1 and the NuRD co-repressor complex. Biochem J 2009; 423:389-400. [PMID: 19686092 PMCID: PMC2762692 DOI: 10.1042/bj20090086] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Multifunctional adaptor protein APPL1 [adaptor protein containing PH (pleckstrin homology) domain, PTB (phosphotyrosine binding) domain and leucine zipper motif] belongs to a growing group of endocytic proteins which actively participate in various stages of signalling pathways. Owing to its interaction with the small GTPase Rab5, APPL1 localizes predominantly to a subpopulation of early endosomes but is also capable of nucleocytoplasmic shuttling. Among its various binding partners, APPL1 was reported to associate with the nuclear co-repressor complex NuRD (nucleosome remodelling and deacetylase), containing both nucleosome remodelling and HDAC (histone deacetylase) activities, but the biochemical basis or functional relevance of this interaction remained unknown. Here we characterized the binding between APPL1 and NuRD in more detail, identifying HDAC2 as the key NuRD subunit responsible for this association. APPL1 interacts with the NuRD complex containing enzymatically active HDAC2 but not HDAC1 as the only deacetylase. However, the cellular levels of HDAC1 can regulate the extent of APPL1–NuRD interactions, which in turn modulates the nucleocytoplasmic distribution of APPL1. Increased binding of APPL1 to NuRD upon silencing of HDAC1 promotes the nuclear localization of APPL1, whereas HDAC1 overexpression exerts an opposite effect. Moreover, we also uncovered a NuRD-independent interaction of APPL1 with HDAC1. APPL1 overexpression affects the composition of the HDAC1-containing NuRD complex and the expression of HDAC1 target p21WAF1/CIP1. Cumulatively, these data reveal a surprising complexity of APPL1 interactions with HDACs, with functional consequences for the modulation of gene expression. In a broader sense, these results contribute to an emerging theme of endocytic proteins playing alternative roles in the cell nucleus.
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29
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van Bergen En Henegouwen PM. Eps15: a multifunctional adaptor protein regulating intracellular trafficking. Cell Commun Signal 2009; 7:24. [PMID: 19814798 PMCID: PMC2767346 DOI: 10.1186/1478-811x-7-24] [Citation(s) in RCA: 56] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2009] [Accepted: 10/08/2009] [Indexed: 12/30/2022] Open
Abstract
Over expression of receptor tyrosine kinases is responsible for the development of a wide variety of malignancies. Termination of growth factor signaling is primarily determined by the down regulation of active growth factor/receptor complexes. In recent years, considerable insight has been gained in the endocytosis and degradation of growth factor receptors. A crucial player in this process is the EGFR Protein tyrosine kinase Substrate #15, or Eps15. This protein functions as a scaffolding adaptor protein and is involved both in secretion and endocytosis. Eps15 has been shown to bind to AP-1 and AP-2 complexes, to bind to inositol lipids and to several other proteins involved in the regulation of intracellular trafficking. In addition, Eps15 has been detected in the nucleus of mammalian cells. Activation of growth factor receptors induces tyrosine phosphorylation and mono-ubiquitination of Eps15. The role of these post translational modifications of Eps15 is still a mystery. It is proposed that Eps15 and its family members Eps15R and Eps15b are involved in the regulation of membrane morphology, which is required for intracellular vesicle formation and trafficking.
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30
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Rashid S, Pilecka I, Torun A, Olchowik M, Bielinska B, Miaczynska M. Endosomal adaptor proteins APPL1 and APPL2 are novel activators of beta-catenin/TCF-mediated transcription. J Biol Chem 2009; 284:18115-28. [PMID: 19433865 PMCID: PMC2709337 DOI: 10.1074/jbc.m109.007237] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2009] [Revised: 05/06/2009] [Indexed: 12/22/2022] Open
Abstract
Canonical Wnt signaling regulates many aspects of cellular physiology and tissue homeostasis during development and in adult organisms. In molecular terms, stimulation by Wnt ligands leads to the stabilization of beta-catenin, its translocation to the nucleus, and stimulation of TCF (T-cell factor)-dependent transcription of target genes. This process is controlled at various stages by a number of regulatory proteins, including transcriptional activators and repressors. Here we demonstrate that the endosomal proteins APPL1 and APPL2 are novel activators of beta-catenin/TCF-mediated transcription. APPL proteins are multifunctional adaptors and effectors of the small GTPase Rab5, which localize to a subpopulation of early endosomes but are also capable of nucleocytoplasmic shuttling. Overexpression of APPL1 or APPL2 protein stimulates the activity of beta-catenin/TCF-dependent reporter construct, whereas silencing of APPL1 reduces it. Both APPL proteins interact directly with Reptin, a transcriptional repressor binding to beta-catenin and HDAC1 (histone deacetylase 1), and this interaction was mapped to the pleckstrin homology domain of APPL1. Moreover, APPL proteins are present in an endogenous complex containing Reptin, beta-catenin, HDAC1, and HDAC2. Overexpression of either APPL protein relieves Reptin-dependent transcriptional repression and correlates with the reduced amounts of HDACs and beta-catenin associated with Reptin as well as with the lower levels of Reptin and HDAC1 on the promoters of beta-catenin target genes. We propose that APPL proteins exert their stimulatory effects on beta-catenin/TCF-dependent transcription by decreasing the activity of a Reptin-containing repressive complex.
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Affiliation(s)
- Sajid Rashid
- From the Laboratory of Cell Biology, International Institute of Molecular and Cell Biology, Ks. Trojdena 4, 02-109 Warsaw, Poland
| | - Iwona Pilecka
- From the Laboratory of Cell Biology, International Institute of Molecular and Cell Biology, Ks. Trojdena 4, 02-109 Warsaw, Poland
| | - Anna Torun
- From the Laboratory of Cell Biology, International Institute of Molecular and Cell Biology, Ks. Trojdena 4, 02-109 Warsaw, Poland
| | - Marta Olchowik
- From the Laboratory of Cell Biology, International Institute of Molecular and Cell Biology, Ks. Trojdena 4, 02-109 Warsaw, Poland
| | - Beata Bielinska
- From the Laboratory of Cell Biology, International Institute of Molecular and Cell Biology, Ks. Trojdena 4, 02-109 Warsaw, Poland
| | - Marta Miaczynska
- From the Laboratory of Cell Biology, International Institute of Molecular and Cell Biology, Ks. Trojdena 4, 02-109 Warsaw, Poland
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Bruce EA, Medcalf L, Crump CM, Noton SL, Stuart AD, Wise HM, Elton D, Bowers K, Digard P. Budding of filamentous and non-filamentous influenza A virus occurs via a VPS4 and VPS28-independent pathway. Virology 2009; 390:268-78. [PMID: 19524996 DOI: 10.1016/j.virol.2009.05.016] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2009] [Revised: 04/02/2009] [Accepted: 05/08/2009] [Indexed: 12/18/2022]
Abstract
The mechanism of membrane scission during influenza A virus budding has been the subject of controversy. We confirm that influenza M1 binds VPS28, a subunit of the ESCRT-1 complex. However, confocal microscopy of infected cells showed no marked colocalisation between M1 and VPS28 or VPS4 ESCRT proteins, or relocalisation of the cellular proteins. Trafficking of HA and M1 appeared normal when endosomal sorting was impaired by expression of inactive VPS4. Overexpression of either isoform of VPS28 or wildtype or dominant negative VPS4 proteins did not alter production of filamentous virions. SiRNA depletion of endogenous VPS28 had no significant effect on influenza virus replication. Furthermore, cells expressing wildtype or dominant-negative VPS4 replicated filamentous and non-filamentous strains of influenza to similar titres, indicating that influenza release is VPS4-independent. Overall, we see no role for the ESCRT pathway in influenza virus budding and the significance of the M1-VPS28 interaction remains to be determined.
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Affiliation(s)
- Emily A Bruce
- Division of Virology, Department of Pathology, University of Cambridge, Tennis Court Road, Cambridge CB2 1QP, UK
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32
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Pyrzynska B, Pilecka I, Miaczynska M. Endocytic proteins in the regulation of nuclear signaling, transcription and tumorigenesis. Mol Oncol 2009; 3:321-38. [PMID: 19577966 DOI: 10.1016/j.molonc.2009.06.001] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2009] [Revised: 06/01/2009] [Accepted: 06/02/2009] [Indexed: 01/14/2023] Open
Abstract
Accumulating evidence argues that many proteins governing membrane sorting during endocytosis participate also in nuclear signaling and transcriptional regulation, mostly by modulating the activity of various nuclear factors. Some adaptors and accessory proteins acting in clathrin-mediated internalization, as well as endosomal sorting proteins can undergo nuclear translocation and affect gene expression directly, while for others the effects may be more indirect. Although it is often unclear to what extent the endocytic and nuclear functions are interrelated, several of such proteins are implicated in the regulation of cell proliferation and tumorigenesis, arguing that their dual-function nature may be of physiological importance.
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Affiliation(s)
- Beata Pyrzynska
- International Institute of Molecular and Cell Biology, Laboratory of Cell Biology, 02-109 Warsaw, Poland
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33
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Abstract
The tyrosine kinase receptor c-Met plays a key role in cell proliferation, morphogenesis, and motility in response to hepatocyte growth factor. C-Met is often altered in cancer and is a major target for therapeutic intervention. Despite knowing a great deal of the molecular machinery downstream of this receptor tyrosine kinase, the spatiotemporal regulation of c-Met signaling still remains elusive. In this issue of the Journal of Cell Biology, Kermorgant and Parker (Kermorgant, S. and P.J. Parker. 2008. J. Cell Biol. 182:855–863) provide evidence for a model in which the c-Met–activated STAT3 signal is mediated by endosomal trafficking. This study elegantly highlights how weak signals can be effectively transmitted to the nucleus by exploiting endosomal compartments, raising important mechanistic implications for the signaling research community.
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Affiliation(s)
- Marisa P McShane
- Max Planck Institute of Molecular Cell Biology and Genetics, 01307 Dresden, Germany
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34
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Sadowski L, Pilecka I, Miaczynska M. Signaling from endosomes: location makes a difference. Exp Cell Res 2008; 315:1601-9. [PMID: 18930045 DOI: 10.1016/j.yexcr.2008.09.021] [Citation(s) in RCA: 138] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2008] [Accepted: 09/23/2008] [Indexed: 01/14/2023]
Abstract
In all transmembrane receptor systems the kinetics of receptor trafficking upon ligand stimulation is maintained in a balance between degradative and recycling pathways in order to keep homeostasis and to strictly control receptor-mediated signaling. Endocytosis is commonly considered as an efficient mechanism of uptake and transport of membrane-associated signaling molecules leading to attenuation of ligand-induced responses. Accumulating evidence, however, shows that signaling from internalized receptors not only continues in endosomal compartments, but that there are also distinct signaling events that require endocytosis. Endocytic organelles form a dynamic network of subcellular compartments, which actively control the timing, amplitude, and specificity of signaling. In this review we provide examples in which signal transduction either requires an active endocytic machinery, or directly originates from various types of endosomes. Based on recent discoveries, we emphasize the close interdependence between signaling and endocytosis, and the physiological relevance of endocytic transport in health and disease.
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Affiliation(s)
- Lukasz Sadowski
- International Institute of Molecular and Cell Biology, Laboratory of Cell Biology, 4 Ks. Trojdena Street, 02-109 Warsaw, Poland
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35
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Prendergast GC, Muller AJ, Ramalingam A, Chang MY. BAR the door: cancer suppression by amphiphysin-like genes. Biochim Biophys Acta Rev Cancer 2008; 1795:25-36. [PMID: 18930786 DOI: 10.1016/j.bbcan.2008.09.001] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2008] [Revised: 08/26/2008] [Accepted: 09/03/2008] [Indexed: 11/17/2022]
Abstract
The evolutionarily conserved amphiphysin-like genes Bin1 and Bin3 function in membrane and actin dynamics, cell polarity, and stress signaling. Recent genetic studies in mice discriminate non-essential roles in endocytic processes commonly ascribed to amphiphysins from essential roles in cancer suppression. Bin1 acts in default pathways of apoptosis and senescence that are triggered by the Myc and Raf oncogenes in primary cells, and Bin1 gene products display a 'moonlighting function' in the nucleus where a variety of other 'endocytic' proteins are also found. Together, genetic investigations in yeast, flies, and mice suggest that amphiphysin-like adapter proteins may suppress cancer by helping integrate cell polarity signals generated by actin and vesicle dynamics with central regulators of cell cycle arrest, apoptosis, and immune surveillance.
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36
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Abstract
From the signaling point of view, endocytosis has long been regarded as a major mechanism of attenuation, through the degradation of signaling receptors and, in some cases, of their ligands. This outlook has changed, over the past decade, as it has become clear that signaling persists in the endocytic route, and that intracellular endocytic stations (the 'signaling endosomes') actually contribute to the sorting of signals in space and time. Endocytosis-mediated recycling of receptors and of signaling molecules to specific regions of the plasma membrane is also coming into focus as a major mechanism in the execution of spatially restricted functions, such as cell motility. In addition, emerging evidence connects endocytosis as a whole, or individual endocytic proteins, to complex cellular programs, such as the control of the cell cycle, mitosis, apoptosis and cell fate determination. Thus, endocytosis seems to be deeply ingrained into the cell regulation blueprint and its subversion is predicted to play an important role in human diseases: first and foremost, cancer.
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Affiliation(s)
- Letizia Lanzetti
- Dipartimento di Scienze Oncologiche, Università degli Studi di Torino, Istituto per la Ricerca e la Cura del Cancro, Candiolo, Turin, Italy
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37
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Kamińska J, Sedek M, Wysocka-Kapcińska M, Zoładek T. Characterization of nuclear localization and nuclear export signals of yeast actin-binding protein Pan1. FEBS Lett 2007; 581:5371-6. [PMID: 17967424 DOI: 10.1016/j.febslet.2007.10.036] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2007] [Revised: 09/23/2007] [Accepted: 10/22/2007] [Indexed: 12/19/2022]
Abstract
Pan1 is an actin patch-associated protein involved in endocytosis. Our studies revealed that in oleate-grown cells Pan1 is located in the nucleus as well as in patches. One of three putative nuclear localization signals (NLS) of Pan1, NLS2, directed beta-galactosidase (beta-gal) to the nucleus. However, GFP-Pan1(886-1219), containing NLS2, was found in the cytoplasm indicating that it may contain a nuclear export signal (NES). A putative Pan1 NES, overlapping with NLS3, re-addressed NLS(H2B)-NES/NLS3-beta-gal from the nucleus to the cytoplasm. Inactivation of the NES allowed NLS3 to be effective. Thus, Pan1 contains functional NLSs and a NES and appears to shuttle in certain circumstances.
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Affiliation(s)
- Joanna Kamińska
- Department of Genetics, Institute of Biochemistry and Biophysics, Polish Academy of Sciences, Pawińskiego 5a, 01-106 Warsaw, Poland.
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