1
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Mahanty S, Bergam P, Belapurkar V, Eluvathingal L, Gupta N, Goud B, Nair D, Raposo G, Setty SRG. Biogenesis of specialized lysosomes in differentiated keratinocytes relies on close apposition with the Golgi apparatus. Cell Death Dis 2024; 15:496. [PMID: 38992005 PMCID: PMC11239851 DOI: 10.1038/s41419-024-06710-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2024] [Revised: 04/23/2024] [Accepted: 04/26/2024] [Indexed: 07/13/2024]
Abstract
Intracellular organelles support cellular physiology in diverse conditions. In the skin, epidermal keratinocytes undergo differentiation with gradual changes in cellular physiology, accompanying remodeling of lysosomes and the Golgi apparatus. However, it was not known whether changes in Golgi and lysosome morphology and their redistribution were linked. Here, we show that disassembled Golgi is distributed in close physical apposition to lysosomes in differentiated keratinocytes. This atypical localization requires the Golgi tethering protein GRASP65, which is associated with both the Golgi and lysosome membranes. Depletion of GRASP65 results in the loss of Golgi-lysosome apposition and the malformation of lysosomes, defined by their aberrant morphology, size, and function. Surprisingly, a trans-Golgi enzyme and secretory Golgi cargoes are extensively localized to the lysosome lumen and secreted to the cell surface, contributing to total protein secretion of differentiated keratinocytes but not in proliferative precursors, indicating that lysosomes acquire specialization during differentiation. We further demonstrate that the secretory function of the Golgi apparatus is critical to maintain keratinocyte lysosomes. Our study uncovers a novel form of Golgi-lysosome cross-talk and its role in maintaining specialized secretory lysosomes in differentiated keratinocytes.
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Affiliation(s)
- Sarmistha Mahanty
- Department of Microbiology and Cell Biology, Indian Institute of Science, Bangalore, 560012, India.
| | - Ptissam Bergam
- Institut Curie, PSL Research University, CNRS, UMR 144, Structure and Membrane Compartments, F-75005, Paris, France
| | - Vivek Belapurkar
- Centre for Neuroscience, Indian Institute of Science, Bangalore, 560012, India
| | | | - Nikita Gupta
- Department of Microbiology and Cell Biology, Indian Institute of Science, Bangalore, 560012, India
| | - Bruno Goud
- Institut Curie, PSL Research University, CNRS, UMR 144, 26 rue d'Ulm, F-75005, Paris, France
| | - Deepak Nair
- Centre for Neuroscience, Indian Institute of Science, Bangalore, 560012, India
| | - Graça Raposo
- Institut Curie, PSL Research University, CNRS, UMR 144, Structure and Membrane Compartments, F-75005, Paris, France
| | - Subba Rao Gangi Setty
- Department of Microbiology and Cell Biology, Indian Institute of Science, Bangalore, 560012, India.
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2
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Meissner JM, Akhmetova K, Szul T, Viktorova EG, Sha B, Bhatt JM, Lee EJ, Kahn RA, Belov GA, Chesnokov I, Sztul E. The Arf-GEF GBF1 undergoes multi-domain structural shifts to activate Arf at the Golgi. Front Cell Dev Biol 2023; 11:1233272. [PMID: 37745300 PMCID: PMC10512945 DOI: 10.3389/fcell.2023.1233272] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2023] [Accepted: 08/29/2023] [Indexed: 09/26/2023] Open
Abstract
Golgi homeostasis require the activation of Arf GTPases by the guanine-nucleotide exchange factor requires GBF1, whose recruitment to the Golgi represents a rate limiting step in the process. GBF1 contains a conserved, catalytic, Sec7 domain (Sec7d) and five additional (DCB, HUS, HDS1-3) domains. Herein, we identify the HDS3 domain as essential for GBF1 membrane association in mammalian cells and document the critical role of HDS3 during the development of Drosophila melanogaster. We show that upon binding to Golgi membranes, GBF1 undergoes conformational changes in regions bracketing the catalytic Sec7d. We illuminate GBF1 interdomain arrangements by negative staining electron microscopy of full-length human GBF1 to show that GBF1 forms an anti-parallel dimer held together by the paired central DCB-HUS core, with two sets of HDS1-3 arms extending outward in opposite directions. The catalytic Sec7d protrudes from the central core as a largely independent domain, but is closely opposed to a previously unassigned α-helix from the HDS1 domain. Based on our data, we propose models of GBF1 engagement on the membrane to provide a paradigm for understanding GBF1-mediated Arf activation required for cellular and organismal function.
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Affiliation(s)
- Justyna M. Meissner
- Department of Cell, Developmental and Integrative Biology, University of Alabama at Birmingham, Birmingham, AL, United States
| | - Katarina Akhmetova
- Department of Biochemistry and Molecular Genetics, University of Alabama at Birmingham, Birmingham, AL, United States
| | - Tomasz Szul
- Department of Cell, Developmental and Integrative Biology, University of Alabama at Birmingham, Birmingham, AL, United States
| | - Ekaterina G. Viktorova
- Department of Veterinary Medicine, Virginia-Maryland Regional College of Veterinary Medicine, University of Maryland, College Park, MD, United States
| | - Bingdong Sha
- Department of Cell, Developmental and Integrative Biology, University of Alabama at Birmingham, Birmingham, AL, United States
| | - Jay M. Bhatt
- Department of Cell, Developmental and Integrative Biology, University of Alabama at Birmingham, Birmingham, AL, United States
| | - Eunjoo J. Lee
- Department of Cell, Developmental and Integrative Biology, University of Alabama at Birmingham, Birmingham, AL, United States
| | - Richard A. Kahn
- Department of Biochemistry, Emory University School of Medicine, Atlanta, GA, United States
| | - George A. Belov
- Department of Veterinary Medicine, Virginia-Maryland Regional College of Veterinary Medicine, University of Maryland, College Park, MD, United States
| | - Igor Chesnokov
- Department of Biochemistry and Molecular Genetics, University of Alabama at Birmingham, Birmingham, AL, United States
| | - Elizabeth Sztul
- Department of Cell, Developmental and Integrative Biology, University of Alabama at Birmingham, Birmingham, AL, United States
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3
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Walton K, Nawara TJ, Angermeier AR, Rosengrant H, Lee E, Wynn B, Victorova E, Belov G, Sztul E. Site-specific phosphorylations of the Arf activator GBF1 differentially regulate GBF1 function in Golgi homeostasis and secretion versus cytokinesis. Sci Rep 2023; 13:13609. [PMID: 37604968 PMCID: PMC10442430 DOI: 10.1038/s41598-023-40705-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2022] [Accepted: 08/16/2023] [Indexed: 08/23/2023] Open
Abstract
Diverse cellular processes, including membrane traffic, lipid homeostasis, cytokinesis, mitochondrial positioning, and cell motility are critically dependent on the Sec7 domain guanine nucleotide exchange factor GBF1. Yet, how the participation of GBF1 in a particular cellular function is regulated is unknown. Here, we show that the phosphorylation of specific highly conserved serine and tyrosine residues within the N-terminal domain of GBF1 differentially regulates its function in maintaining Golgi homeostasis and facilitating secretion versus its role in cytokinesis. Specifically, GBF1 mutants containing single amino acid substitutions that mimic a stably phosphorylated S233, S371, Y377, and Y515 or the S233A mutant that can't be phosphorylated are fully able to maintain Golgi architecture and support cargo traffic through the secretory pathway when assessed in multiple functional assays. However, the same mutants cause multi-nucleation when expressed in cells, and appear to inhibit the progression through mitosis and the resolution of cytokinetic bridges. Thus, GBF1 participates in distinct interactive networks when mediating Golgi homeostasis and secretion versus facilitating cytokinesis, and GBF1 integration into such networks is differentially regulated by the phosphorylation of specific GBF1 residues.
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Affiliation(s)
- Kendall Walton
- Department of Cell, Developmental, and Integrative Biology, University of Alabama at Birmingham, 1918 University Boulevard, MCLM 668, Birmingham, AL, 35233-2008, USA.
| | - Tomasz J Nawara
- Department of Cell, Developmental, and Integrative Biology, University of Alabama at Birmingham, 1918 University Boulevard, MCLM 668, Birmingham, AL, 35233-2008, USA
| | - Allyson R Angermeier
- Department of Cell, Developmental, and Integrative Biology, University of Alabama at Birmingham, 1918 University Boulevard, MCLM 668, Birmingham, AL, 35233-2008, USA
| | - Hadley Rosengrant
- Department of Cell, Developmental, and Integrative Biology, University of Alabama at Birmingham, 1918 University Boulevard, MCLM 668, Birmingham, AL, 35233-2008, USA
| | - Eunjoo Lee
- Department of Cell, Developmental, and Integrative Biology, University of Alabama at Birmingham, 1918 University Boulevard, MCLM 668, Birmingham, AL, 35233-2008, USA
| | - Bridge Wynn
- Department of Cell, Developmental, and Integrative Biology, University of Alabama at Birmingham, 1918 University Boulevard, MCLM 668, Birmingham, AL, 35233-2008, USA
| | - Ekaterina Victorova
- Department of Veterinary Medicine, Virginia-Maryland College of Veterinary Medicine, University of Maryland, College Park, MD, 20742, USA
| | - George Belov
- Department of Veterinary Medicine, Virginia-Maryland College of Veterinary Medicine, University of Maryland, College Park, MD, 20742, USA
| | - Elizabeth Sztul
- Department of Cell, Developmental, and Integrative Biology, University of Alabama at Birmingham, 1918 University Boulevard, MCLM 668, Birmingham, AL, 35233-2008, USA
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4
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B.R. R, Shah N, Joshi P, Madhusudan MS, Balasubramanian N. Kinetics of Arf1 inactivation regulates Golgi organisation and function in non-adherent fibroblasts. Biol Open 2023; 12:bio059669. [PMID: 36946871 PMCID: PMC10187640 DOI: 10.1242/bio.059669] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2022] [Accepted: 03/13/2023] [Indexed: 03/23/2023] Open
Abstract
Arf1 belongs to the Arf family of small GTPases that localise at the Golgi and plasma membrane. Active Arf1 plays a crucial role in regulating Golgi organisation and function. In mouse fibroblasts, loss of adhesion triggers a consistent drop (∼50%) in Arf1 activation that causes the Golgi to disorganise but not fragment. In suspended cells, the trans-Golgi (GalTase) disperses more prominently than cis-Golgi (Man II), accompanied by increased active Arf1 (detected using GFP-ABD: ARHGAP10 Arf1 binding domain) associated with the cis-Golgi compartment. Re-adhesion restores Arf1 activation at the trans-Golgi as it reorganises. Arf1 activation at the Golgi is regulated by Arf1 Guanine nucleotide exchange factors (GEFs), GBF1, and BIG1/2. In non-adherent fibroblasts, the cis-medial Golgi provides a unique setting to test and understand the role GEF-mediated Arf1 activation has in regulating Golgi organisation. Labelled with Man II-GFP, non-adherent fibroblasts treated with increasing concentrations of Brefeldin-A (BFA) (which inhibits BIG1/2 and GBF1) or Golgicide A (GCA) (which inhibits GBF1 only) comparably decrease active Arf1 levels. They, however, cause a concentration-dependent increase in cis-medial Golgi fragmentation and fusion with the endoplasmic reticulum (ER). Using selected BFA and GCA concentrations, we find a change in the kinetics of Arf1 inactivation could mediate this by regulating cis-medial Golgi localisation of GBF1. On loss of adhesion, a ∼50% drop in Arf1 activation over 120 min causes the Golgi to disorganise. The kinetics of this drop, when altered by BFA or GCA treatment causes a similar decline in Arf1 activation but over 10 min. This causes the Golgi to now fragment which affects cell surface glycosylation and re-adherent cell spreading. Using non-adherent fibroblasts this study reveals the kinetics of Arf1 inactivation, with active Arf1 levels, to be vital for Golgi organisation and function.
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Affiliation(s)
- Rajeshwari B.R.
- Indian Institute of Science Education and Research (IISER) Pune, Dr Homi Bhabha Road, Pashan, Pune, Maharashtra 411008, India
| | - Nikita Shah
- Indian Institute of Science Education and Research (IISER) Pune, Dr Homi Bhabha Road, Pashan, Pune, Maharashtra 411008, India
| | - Prachi Joshi
- Indian Institute of Science Education and Research (IISER) Pune, Dr Homi Bhabha Road, Pashan, Pune, Maharashtra 411008, India
| | - M. S. Madhusudan
- Indian Institute of Science Education and Research (IISER) Pune, Dr Homi Bhabha Road, Pashan, Pune, Maharashtra 411008, India
| | - Nagaraj Balasubramanian
- Indian Institute of Science Education and Research (IISER) Pune, Dr Homi Bhabha Road, Pashan, Pune, Maharashtra 411008, India
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5
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Navare AT, Mast FD, Olivier JP, Bertomeu T, Neal ML, Carpp LN, Kaushansky A, Coulombe-Huntington J, Tyers M, Aitchison JD. Viral protein engagement of GBF1 induces host cell vulnerability through synthetic lethality. J Cell Biol 2022; 221:213618. [PMID: 36305789 PMCID: PMC9623979 DOI: 10.1083/jcb.202011050] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2020] [Revised: 06/15/2022] [Accepted: 08/26/2022] [Indexed: 12/14/2022] Open
Abstract
Viruses co-opt host proteins to carry out their lifecycle. Repurposed host proteins may thus become functionally compromised; a situation analogous to a loss-of-function mutation. We term such host proteins as viral-induced hypomorphs. Cells bearing cancer driver loss-of-function mutations have successfully been targeted with drugs perturbing proteins encoded by the synthetic lethal (SL) partners of cancer-specific mutations. Similarly, SL interactions of viral-induced hypomorphs can potentially be targeted as host-based antiviral therapeutics. Here, we use GBF1, which supports the infection of many RNA viruses, as a proof-of-concept. GBF1 becomes a hypomorph upon interaction with the poliovirus protein 3A. Screening for SL partners of GBF1 revealed ARF1 as the top hit, disruption of which selectively killed cells that synthesize 3A alone or in the context of a poliovirus replicon. Thus, viral protein interactions can induce hypomorphs that render host cells selectively vulnerable to perturbations that leave uninfected cells otherwise unscathed. Exploiting viral-induced vulnerabilities could lead to broad-spectrum antivirals for many viruses, including SARS-CoV-2.
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Affiliation(s)
- Arti T. Navare
- Center for Global Infectious Disease Research, Seattle Children’s Research Institute, Seattle, WA
| | - Fred D. Mast
- Center for Global Infectious Disease Research, Seattle Children’s Research Institute, Seattle, WA
| | - Jean Paul Olivier
- Center for Global Infectious Disease Research, Seattle Children’s Research Institute, Seattle, WA
| | - Thierry Bertomeu
- Institute for Research in Immunology and Cancer, Université de Montréal, Montreal, Quebec, Canada
| | - Maxwell L. Neal
- Center for Global Infectious Disease Research, Seattle Children’s Research Institute, Seattle, WA
| | | | - Alexis Kaushansky
- Center for Global Infectious Disease Research, Seattle Children’s Research Institute, Seattle, WA,Department of Pediatrics, University of Washington, Seattle, WA
| | | | - Mike Tyers
- Institute for Research in Immunology and Cancer, Université de Montréal, Montreal, Quebec, Canada
| | - John D. Aitchison
- Center for Global Infectious Disease Research, Seattle Children’s Research Institute, Seattle, WA,Department of Pediatrics, University of Washington, Seattle, WA,Department of Biochemistry, University of Washington, Seattle, WA,Correspondence to John D. Aitchison:
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6
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Malis Y, Hirschberg K, Kaether C. Hanging the coat on a collar: Same function but different localization and mechanism for COPII. Bioessays 2022; 44:e2200064. [DOI: 10.1002/bies.202200064] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2022] [Revised: 07/25/2022] [Accepted: 07/26/2022] [Indexed: 11/09/2022]
Affiliation(s)
- Yehonathan Malis
- Department of Pathology, Sackler School of Medicine Tel‐Aviv University Tel Aviv Israel
| | - Koret Hirschberg
- Department of Pathology, Sackler School of Medicine Tel‐Aviv University Tel Aviv Israel
| | - Christoph Kaether
- Leibniz Institute for Age Research – Fritz Lipmann Institute Jena Germany
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7
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Vozdek R, Pramstaller PP, Hicks AA. Functional Screening of Parkinson's Disease Susceptibility Genes to Identify Novel Modulators of α-Synuclein Neurotoxicity in Caenorhabditis elegans. Front Aging Neurosci 2022; 14:806000. [PMID: 35572147 PMCID: PMC9093606 DOI: 10.3389/fnagi.2022.806000] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2021] [Accepted: 03/18/2022] [Indexed: 11/24/2022] Open
Abstract
Idiopathic Parkinson's disease (PD) is characterized by progressive loss of dopaminergic (DA) neurons during aging. The pathological hallmark of PD is the Lewy body detected in postmortem brain tissue, which is mainly composed of aggregated α-Synuclein (αSyn). However, it is estimated that 90% of PD cases have unknown pathogenetic triggers. Here, we generated a new transgenic Caenorhabditis elegans PD model eraIs1 expressing green fluorescent protein- (GFP-) based reporter of human αSyn in DA neurons, and exhibited a nice readout of the developed αSyn inclusions in DA neurons, leading to their degeneration during aging. Using these animals in a preliminary reverse genetic screening of >100-PD genome-wide association study- (GWAS-) based susceptibility genes, we identified 28 orthologs of C. elegans and their inactivation altered the phenotype of eraIs1; 10 knockdowns exhibited reduced penetrance of αSyn:Venus inclusions formed in the axons of cephalic (CEP) DA neurons, 18 knockdowns exhibited increased penetrance of disrupted CEP dendrite integrity among which nine knockdowns also exhibited disrupted neuronal morphology independent of the expressed αSyn reporter. Loss-of-function alleles of the five identified genes, such as sac-2, rig-6 or lfe-2, unc-43, and nsf-1, modulated the corresponding eraIs1 phenotype, respectively, and supported the RNA interference (RNAi) data. The Western blot analysis showed that the levels of insoluble αSyn:Venus were not correlated with the observed phenotypes in these mutants. However, RNAi of 12 identified modulators reduced the formation of pro-aggregating polyglutamine Q40:YFP foci in muscle cells, suggesting the possible role of these genes in cellular proteotoxicity. Therefore, modulators identified by their associated biological pathways, such as calcium signaling or vesicular trafficking, represent new potential therapeutic targets for neurodegenerative proteopathies and other diseases associated with aging.
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Affiliation(s)
- Roman Vozdek
- Institute for Biomedicine, Eurac Research, Affiliated Institute of the University of Lübeck, Bolzano, Italy
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8
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Del Giudice S, De Luca V, Parizadeh S, Russo D, Luini A, Di Martino R. Endogenous and Exogenous Regulatory Signaling in the Secretory Pathway: Role of Golgi Signaling Molecules in Cancer. Front Cell Dev Biol 2022; 10:833663. [PMID: 35399533 PMCID: PMC8984190 DOI: 10.3389/fcell.2022.833663] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2021] [Accepted: 03/03/2022] [Indexed: 11/29/2022] Open
Abstract
The biosynthetic transport route that constitutes the secretory pathway plays a fundamental role in the cell, providing to the synthesis and transport of around one third of human proteins and most lipids. Signaling molecules within autoregulatory circuits on the intracellular membranes of the secretory pathway regulate these processes, especially at the level of the Golgi complex. Indeed, cancer cells can hijack several of these signaling molecules, and therefore also the underlying regulated processes, to bolster their growth or gain more aggressive phenotypes. Here, we review the most important autoregulatory circuits acting on the Golgi, emphasizing the role of specific signaling molecules in cancer. In fact, we propose to draw awareness to highlight the Golgi-localized regulatory systems as potential targets in cancer therapy.
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Affiliation(s)
| | | | | | | | - Alberto Luini
- *Correspondence: Alberto Luini, ; Rosaria Di Martino,
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9
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Chia J, Wang SC, Wee S, Gill DJ, Tay F, Kannan S, Verma CS, Gunaratne J, Bard FA. Src activates retrograde membrane traffic through phosphorylation of GBF1. eLife 2021; 10:68678. [PMID: 34870592 PMCID: PMC8727025 DOI: 10.7554/elife.68678] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2021] [Accepted: 12/05/2021] [Indexed: 12/14/2022] Open
Abstract
The Src tyrosine kinase controls cancer-critical protein glycosylation through Golgi to ER relocation of GALNTs enzymes. How Src induces this trafficking event is unknown. Golgi to ER transport depends on the GTP exchange factor (GEF) GBF1 and small GTPase Arf1. Here, we show that Src induces the formation of tubular transport carriers containing GALNTs. The kinase phosphorylates GBF1 on 10 tyrosine residues; two of them, Y876 and Y898, are located near the C-terminus of the Sec7 GEF domain. Their phosphorylation promotes GBF1 binding to the GTPase; molecular modeling suggests partial melting of the Sec7 domain and intramolecular rearrangement. GBF1 mutants defective for these rearrangements prevent binding, carrier formation, and GALNTs relocation, while phosphomimetic GBF1 mutants induce tubules. In sum, Src promotes GALNTs relocation by promoting GBF1 binding to Arf1. Based on residue conservation, similar regulation of GEF-Arf complexes by tyrosine phosphorylation could be a conserved and widespread mechanism.
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Affiliation(s)
- Joanne Chia
- Institute of Molecular and Cell Biology, Singapore, Singapore
| | - Shyi-Chyi Wang
- Institute of Molecular and Cell Biology, Singapore, Singapore.,Institute of Bioengineering and Bioimaging, Singapore, Singapore
| | - Sheena Wee
- Institute of Molecular and Cell Biology, Singapore, Singapore
| | | | - Felicia Tay
- Institute of Molecular and Cell Biology, Singapore, Singapore
| | | | - Chandra S Verma
- Bioinformatics Institute, Singapore, Singapore.,Department of Biological Sciences, National University of Singapore, Singapore, Singapore.,School of Biological Sciences, Nanyang Technological University, Singapore, Singapore
| | | | - Frederic A Bard
- Institute of Molecular and Cell Biology, Singapore, Singapore
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10
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Choi K, Yang A, Baek J, Jeong H, Kang Y, Baek W, Kim JC, Kang M, Choi M, Ham Y, Son MJ, Han SB, Kim J, Jang JH, Ahn JS, Shen H, Woo SH, Kim JH, Cho S. Regulation of Survival Motor Neuron Gene Expression by Calcium Signaling. Int J Mol Sci 2021; 22:ijms221910234. [PMID: 34638572 PMCID: PMC8508836 DOI: 10.3390/ijms221910234] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2021] [Revised: 09/07/2021] [Accepted: 09/16/2021] [Indexed: 11/21/2022] Open
Abstract
Spinal muscular atrophy (SMA) is caused by homozygous survival of motor neurons 1 (SMN1) gene deletion, leaving a duplicate gene, SMN2, as the sole source of SMN protein. However, a defect in SMN2 splicing, involving exon 7 skipping, results in a low level of functional SMN protein. Therefore, the upregulation of SMN protein expression from the SMN2 gene is generally considered to be one of the best therapeutic strategies to treat SMA. Most of the SMA drug discovery is based on synthetic compounds, and very few natural compounds have been explored thus far. Here, we performed an unbiased mechanism-independent and image-based screen of a library of microbial metabolites in SMA fibroblasts using an SMN-specific immunoassay. In doing so, we identified brefeldin A (BFA), a well-known inhibitor of ER-Golgi protein trafficking, as a strong inducer of SMN protein. The profound increase in SMN protein was attributed to, in part, the rescue of the SMN2 pre-mRNA splicing defect. Intriguingly, BFA increased the intracellular calcium concentration, and the BFA-induced exon 7 inclusion of SMN2 splicing, was abrogated by the depletion of intracellular calcium and by the pharmacological inhibition of calcium/calmodulin-dependent kinases (CaMKs). Moreover, BFA considerably reduced the expression of Tra2-β and SRSF9 proteins in SMA fibroblasts and enhanced the binding of PSF and hnRNP M to an exonic splicing enhancer (ESE) of exon 7. Together, our results demonstrate a significant role for calcium and its signaling on the regulation of SMN splicing, probably through modulating the expression/activity of splicing factors.
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Affiliation(s)
- Kwangman Choi
- Natural Medicine Research Center, Korea Research Institute of Bioscience and Biotechnology, Cheongju 28116, Korea; (K.C.); (A.Y.); (J.B.); (H.J.); (M.K.); (M.C.); (Y.H.)
- Department of Medical Biotechnology, SoonChunHyang University, Asan 31538, Korea
| | - Ansook Yang
- Natural Medicine Research Center, Korea Research Institute of Bioscience and Biotechnology, Cheongju 28116, Korea; (K.C.); (A.Y.); (J.B.); (H.J.); (M.K.); (M.C.); (Y.H.)
- College of Pharmacy, Chungbuk National University, Cheongju 28160, Korea;
| | - Jiyeon Baek
- Natural Medicine Research Center, Korea Research Institute of Bioscience and Biotechnology, Cheongju 28116, Korea; (K.C.); (A.Y.); (J.B.); (H.J.); (M.K.); (M.C.); (Y.H.)
- College of Pharmacy, Chungbuk National University, Cheongju 28160, Korea;
| | - Hyejeong Jeong
- Natural Medicine Research Center, Korea Research Institute of Bioscience and Biotechnology, Cheongju 28116, Korea; (K.C.); (A.Y.); (J.B.); (H.J.); (M.K.); (M.C.); (Y.H.)
- College of Pharmacy, Chungbuk National University, Cheongju 28160, Korea;
| | - Yura Kang
- Department of Cancer Biomedical Science, Graduate School of Cancer Science and Policy, National Cancer Center, Goyang 10408, Korea; (Y.K.); (W.B.)
- Cancer Molecular Biology Branch, Division of Cancer Biology, Research Institute, National Cancer Center, Goyang 10408, Korea
| | - Woosun Baek
- Department of Cancer Biomedical Science, Graduate School of Cancer Science and Policy, National Cancer Center, Goyang 10408, Korea; (Y.K.); (W.B.)
- Cancer Molecular Biology Branch, Division of Cancer Biology, Research Institute, National Cancer Center, Goyang 10408, Korea
| | - Joon-Chul Kim
- College of Pharmacy, Chungnam National University, Daejeon 34134, Korea; (J.-C.K.); (M.-J.S.)
| | - Mingu Kang
- Natural Medicine Research Center, Korea Research Institute of Bioscience and Biotechnology, Cheongju 28116, Korea; (K.C.); (A.Y.); (J.B.); (H.J.); (M.K.); (M.C.); (Y.H.)
- College of Pharmacy, Chungbuk National University, Cheongju 28160, Korea;
| | - Miri Choi
- Natural Medicine Research Center, Korea Research Institute of Bioscience and Biotechnology, Cheongju 28116, Korea; (K.C.); (A.Y.); (J.B.); (H.J.); (M.K.); (M.C.); (Y.H.)
- College of Pharmacy, Chungbuk National University, Cheongju 28160, Korea;
| | - Youngwook Ham
- Natural Medicine Research Center, Korea Research Institute of Bioscience and Biotechnology, Cheongju 28116, Korea; (K.C.); (A.Y.); (J.B.); (H.J.); (M.K.); (M.C.); (Y.H.)
- Department of Biomolecular Science, KRIBB School of Bioscience, Korea University of Science and Technology, Daejeon 34113, Korea; (J.-H.J.); (J.S.A.)
| | - Min-Jeong Son
- College of Pharmacy, Chungnam National University, Daejeon 34134, Korea; (J.-C.K.); (M.-J.S.)
| | - Sang-Bae Han
- College of Pharmacy, Chungbuk National University, Cheongju 28160, Korea;
| | - Janghwan Kim
- Stem Cell Research Center, Korea Research Institute of Bioscience and Biotechnology, Daejeon 34141, Korea;
| | - Jae-Hyuk Jang
- Department of Biomolecular Science, KRIBB School of Bioscience, Korea University of Science and Technology, Daejeon 34113, Korea; (J.-H.J.); (J.S.A.)
- Anticancer Agent Research Center, Korea Research Institute of Bioscience and Biotechnology, Cheongju 28116, Korea
| | - Jong Seog Ahn
- Department of Biomolecular Science, KRIBB School of Bioscience, Korea University of Science and Technology, Daejeon 34113, Korea; (J.-H.J.); (J.S.A.)
- Anticancer Agent Research Center, Korea Research Institute of Bioscience and Biotechnology, Cheongju 28116, Korea
| | - Haihong Shen
- Gwangju Institute of Science and Technology, School of life Sciences, Gwangju 61005, Korea;
| | - Sun-Hee Woo
- College of Pharmacy, Chungnam National University, Daejeon 34134, Korea; (J.-C.K.); (M.-J.S.)
- Correspondence: (S.-H.W.); (J.H.K.); (S.C.); Tel.: +82-42-821-5924 (S.-H.W.); +82-31-920-2204 (J.H.K.); +82-43-240-6105 (S.C.); Fax: +82-42-823-6566 (S.-H.W.); +82-31-920-2006 (J.H.K.); +82-43-240-6159 (S.C)
| | - Jong Heon Kim
- Department of Cancer Biomedical Science, Graduate School of Cancer Science and Policy, National Cancer Center, Goyang 10408, Korea; (Y.K.); (W.B.)
- Cancer Molecular Biology Branch, Division of Cancer Biology, Research Institute, National Cancer Center, Goyang 10408, Korea
- Correspondence: (S.-H.W.); (J.H.K.); (S.C.); Tel.: +82-42-821-5924 (S.-H.W.); +82-31-920-2204 (J.H.K.); +82-43-240-6105 (S.C.); Fax: +82-42-823-6566 (S.-H.W.); +82-31-920-2006 (J.H.K.); +82-43-240-6159 (S.C)
| | - Sungchan Cho
- Natural Medicine Research Center, Korea Research Institute of Bioscience and Biotechnology, Cheongju 28116, Korea; (K.C.); (A.Y.); (J.B.); (H.J.); (M.K.); (M.C.); (Y.H.)
- Department of Biomolecular Science, KRIBB School of Bioscience, Korea University of Science and Technology, Daejeon 34113, Korea; (J.-H.J.); (J.S.A.)
- Correspondence: (S.-H.W.); (J.H.K.); (S.C.); Tel.: +82-42-821-5924 (S.-H.W.); +82-31-920-2204 (J.H.K.); +82-43-240-6105 (S.C.); Fax: +82-42-823-6566 (S.-H.W.); +82-31-920-2006 (J.H.K.); +82-43-240-6159 (S.C)
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11
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Adarska P, Wong-Dilworth L, Bottanelli F. ARF GTPases and Their Ubiquitous Role in Intracellular Trafficking Beyond the Golgi. Front Cell Dev Biol 2021; 9:679046. [PMID: 34368129 PMCID: PMC8339471 DOI: 10.3389/fcell.2021.679046] [Citation(s) in RCA: 31] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2021] [Accepted: 06/30/2021] [Indexed: 11/13/2022] Open
Abstract
Molecular switches of the ADP-ribosylation factor (ARF) GTPase family coordinate intracellular trafficking at all sorting stations along the secretory pathway, from the ER-Golgi-intermediate compartment (ERGIC) to the plasma membrane (PM). Their GDP-GTP switch is essential to trigger numerous processes, including membrane deformation, cargo sorting and recruitment of downstream coat proteins and effectors, such as lipid modifying enzymes. While ARFs (in particular ARF1) had mainly been studied in the context of coat protein recruitment at the Golgi, COPI/clathrin-independent roles have emerged in the last decade. Here we review the roles of human ARF1-5 GTPases in cellular trafficking with a particular emphasis on their roles in post-Golgi secretory trafficking and in sorting in the endo-lysosomal system.
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Affiliation(s)
- Petia Adarska
- Institut für Biochemie, Freie Universität Berlin, Berlin, Germany
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12
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Claeys L, Storoni S, Eekhoff M, Elting M, Wisse L, Pals G, Bravenboer N, Maugeri A, Micha D. Collagen transport and related pathways in Osteogenesis Imperfecta. Hum Genet 2021; 140:1121-1141. [PMID: 34169326 PMCID: PMC8263409 DOI: 10.1007/s00439-021-02302-2] [Citation(s) in RCA: 38] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2021] [Accepted: 06/08/2021] [Indexed: 12/16/2022]
Abstract
Osteogenesis Imperfecta (OI) comprises a heterogeneous group of patients who share bone fragility and deformities as the main characteristics, albeit with different degrees of severity. Phenotypic variation also exists in other connective tissue aspects of the disease, complicating disease classification and disease course prediction. Although collagen type I defects are long established as the primary cause of the bone pathology, we are still far from comprehending the complete mechanism. In the last years, the advent of next generation sequencing has triggered the discovery of many new genetic causes for OI, helping to draw its molecular landscape. It has become clear that, in addition to collagen type I genes, OI can be caused by multiple proteins connected to different parts of collagen biosynthesis. The production of collagen entails a complex process, starting from the production of the collagen Iα1 and collagen Iα2 chains in the endoplasmic reticulum, during and after which procollagen is subjected to a plethora of posttranslational modifications by chaperones. After reaching the Golgi organelle, procollagen is destined to the extracellular matrix where it forms collagen fibrils. Recently discovered mutations in components of the retrograde transport of chaperones highlight its emerging role as critical contributor of OI development. This review offers an overview of collagen regulation in the context of recent gene discoveries, emphasizing the significance of transport disruptions in the OI mechanism. We aim to motivate exploration of skeletal fragility in OI from the perspective of these pathways to identify regulatory points which can hint to therapeutic targets.
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Affiliation(s)
- Lauria Claeys
- Department of Clinical Genetics, Amsterdam UMC, Amsterdam Movement Sciences, Vrije Universiteit Amsterdam, Amsterdam, The Netherlands
| | - Silvia Storoni
- Department of Internal Medicine Section Endocrinology, Amsterdam UMC, Amsterdam Movement Sciences, Vrije Universiteit Amsterdam, Amsterdam, The Netherlands
| | - Marelise Eekhoff
- Department of Internal Medicine Section Endocrinology, Amsterdam UMC, Amsterdam Movement Sciences, Vrije Universiteit Amsterdam, Amsterdam, The Netherlands
| | - Mariet Elting
- Department of Clinical Genetics, Amsterdam UMC, Amsterdam Movement Sciences, Vrije Universiteit Amsterdam, Amsterdam, The Netherlands
| | - Lisanne Wisse
- Department of Clinical Genetics, Amsterdam UMC, Amsterdam Movement Sciences, Vrije Universiteit Amsterdam, Amsterdam, The Netherlands
| | - Gerard Pals
- Department of Clinical Genetics, Amsterdam UMC, Amsterdam Movement Sciences, Vrije Universiteit Amsterdam, Amsterdam, The Netherlands
| | - Nathalie Bravenboer
- Department of Clinical Chemistry, Amsterdam /UMC, Amsterdam Movement Sciences, Vrije Universiteit Amsterdam, Amsterdam, The Netherlands
| | - Alessandra Maugeri
- Department of Clinical Genetics, Amsterdam UMC, Amsterdam Movement Sciences, Vrije Universiteit Amsterdam, Amsterdam, The Netherlands
| | - Dimitra Micha
- Department of Clinical Genetics, Amsterdam UMC, Amsterdam Movement Sciences, Vrije Universiteit Amsterdam, Amsterdam, The Netherlands.
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13
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Zou YJ, Shan MM, Pan ZN, Pan MH, Li XH, Sun SC. Loss of Arf Guanine Nucleotide Exchange Factor GBF1 Activity Disturbs Organelle Dynamics in Mouse Oocytes. MICROSCOPY AND MICROANALYSIS : THE OFFICIAL JOURNAL OF MICROSCOPY SOCIETY OF AMERICA, MICROBEAM ANALYSIS SOCIETY, MICROSCOPICAL SOCIETY OF CANADA 2021; 27:400-408. [PMID: 33478608 DOI: 10.1017/s1431927620024885] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
GBF1 [Golgi brefeldin A (BFA) resistance factor 1] is a member of the guanine nucleotide exchange factors Arf family. GBF1 localizes at the cis-Golgi and endoplasmic reticulum (ER)-Golgi intermediate compartment where it participates in ER-Golgi traffic by assisting in the recruitment of the coat protein COPI. However, the roles of GBF1 in oocyte meiotic maturation are still unknown. In the present study, we investigated the regulatory functions of GBF1 in mouse oocyte organelle dynamics. In our results, GBF1 was stably expressed during oocyte maturation, and GBF1 localized at the spindle periphery during metaphase I. Inhibiting GBF1 activity led to aberrant accumulation of the Golgi apparatus around the spindle. This may be due to the effects of GBF1 on the localization of GM130, as GBF1 co-localized with GM130 and inhibiting GBF1 induced condensation of GM130. Moreover, the loss of GBF1 activity affected the ER distribution and induced ER stress, as shown by increased GRP78 expression. Mitochondrial localization and functions were affected, as the mitochondrial membrane potential was altered. Taken together, these results suggest that GBF1 has wide-ranging effects on the distribution and functions of Golgi apparatus, ER, and mitochondria as well as normal polar body formation in mouse oocytes.
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Affiliation(s)
- Yuan-Jing Zou
- College of Animal Science and Technology, Nanjing Agricultural University, Nanjing210095, China
| | - Meng-Meng Shan
- College of Animal Science and Technology, Nanjing Agricultural University, Nanjing210095, China
| | - Zhen-Nan Pan
- College of Animal Science and Technology, Nanjing Agricultural University, Nanjing210095, China
| | - Meng-Hao Pan
- College of Animal Science and Technology, Nanjing Agricultural University, Nanjing210095, China
| | - Xiao-Han Li
- College of Animal Science and Technology, Nanjing Agricultural University, Nanjing210095, China
| | - Shao-Chen Sun
- College of Animal Science and Technology, Nanjing Agricultural University, Nanjing210095, China
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14
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Sager G, Szul T, Lee E, Kawai R, Presley JF, Sztul E. Modeling the dynamic behaviors of the COPI vesicle formation regulators, the small GTPase Arf1 and its activating Sec7 guanine nucleotide exchange factor GBF1 on Golgi membranes. Mol Biol Cell 2021; 32:446-459. [PMID: 33405949 PMCID: PMC8098855 DOI: 10.1091/mbc.e20-09-0587] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
The components and subprocesses underlying the formation of COPI-coated vesicles at the Golgi are well understood. The coating cascade is initiated after the small GTPase Arf1 is activated by the Sec7 domain–containing guanine nucleotide exchange factor GBF1 (Golgi brefeldin A resistant guanine nucleotide exchange factor 1). This causes a conformational shift within Arf1 that facilitates stable association of Arf1 with the membrane, a process required for subsequent recruitment of the COPI coat. Although we have atomic-level knowledge of Arf1 activation by Sec7 domain–containing GEFs, our understanding of the biophysical processes regulating Arf1 and GBF1 dynamics is limited. We used fluorescence recovery after photobleaching data and kinetic Monte Carlo simulation to assess the behavior of Arf1 and GBF1 during COPI vesicle formation in live cells. Our analyses suggest that Arf1 and GBF1 associate with Golgi membranes independently, with an excess of GBF1 relative to Arf1. Furthermore, the GBF1-mediated Arf1 activation is much faster than GBF1 cycling on/off the membrane, suggesting that GBF1 is regulated by processes other than its interactions Arf1. Interestingly, modeling the behavior of the catalytically inactive GBF1/E794K mutant stabilized on the membrane is inconsistent with the formation of a stable complex between it and an endogenous Arf1 and suggests that GBF1/E794K is stabilized on the membrane independently of complex formation.
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Affiliation(s)
- Garrett Sager
- Department of Cell, Developmental, and Integrative Biology, University of Alabama at Birmingham, Birmingham, AL 35924.,Department of Physics, University of Alabama at Birmingham, Birmingham, AL 35924
| | - Tomasz Szul
- Department of Cell, Developmental, and Integrative Biology, University of Alabama at Birmingham, Birmingham, AL 35924
| | - Eunjoo Lee
- Department of Cell, Developmental, and Integrative Biology, University of Alabama at Birmingham, Birmingham, AL 35924
| | - Ryoichi Kawai
- Department of Physics, University of Alabama at Birmingham, Birmingham, AL 35924
| | - John F Presley
- Department of Anatomy & Cell Biology, McGill University, Montreal, QC H3A 0C7, Canada
| | - Elizabeth Sztul
- Department of Cell, Developmental, and Integrative Biology, University of Alabama at Birmingham, Birmingham, AL 35924
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15
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Enterovirus Infection Induces Massive Recruitment of All Isoforms of Small Cellular Arf GTPases to the Replication Organelles. J Virol 2020; 95:JVI.01629-20. [PMID: 33087467 DOI: 10.1128/jvi.01629-20] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2020] [Accepted: 10/18/2020] [Indexed: 12/12/2022] Open
Abstract
Enterovirus replication requires the cellular protein GBF1, a guanine nucleotide exchange factor for small Arf GTPases. When activated, Arfs associate with membranes, where they regulate numerous steps of membrane homeostasis. The requirement for GBF1 implies that Arfs are important for replication, but which of the different Arfs function(s) during replication remains poorly understood. Here, we established cell lines expressing each of the human Arfs fused to a fluorescent tag and investigated their behavior during enterovirus infection. Arf1 was the first to be recruited to the replication organelles, where it strongly colocalized with the viral antigen 2B and mature virions but not double-stranded RNA. By the end of the infectious cycle, Arf3, Arf4, Arf5, and Arf6 were also concentrated on the replication organelles. Once on the replication membranes, all Arfs except Arf3 were no longer sensitive to inhibition of GBF1, suggesting that in infected cells they do not actively cycle between GTP- and GDP-bound states. Only the depletion of Arf1, but not other class 1 and 2 Arfs, significantly increased the sensitivity of replication to GBF1 inhibition. Surprisingly, depletion of Arf6, a class 3 Arf, normally implicated in plasma membrane events, also increased the sensitivity to GBF1 inhibition. Together, our results suggest that GBF1-dependent Arf1 activation directly supports the development and/or functioning of the replication complexes and that Arf6 plays a previously unappreciated role in viral replication. Our data reveal a complex pattern of Arf activation in enterovirus-infected cells that may contribute to the resilience of viral replication in different cellular environments.IMPORTANCE Enteroviruses include many known and emerging pathogens, such as poliovirus, enteroviruses 71 and D68, and others. However, licensed vaccines are available only against poliovirus and enterovirus 71, and specific anti-enterovirus therapeutics are lacking. Enterovirus infection induces the massive remodeling of intracellular membranes and the development of specialized domains harboring viral replication complexes, replication organelles. Here, we investigated the roles of small Arf GTPases during enterovirus infection. Arfs control distinct steps in intracellular membrane traffic, and one of the Arf-activating proteins, GBF1, is a cellular factor required for enterovirus replication. We found that all Arfs expressed in human cells, including Arf6, normally associated with the plasma membrane, are recruited to the replication organelles and that Arf1 appears to be the most important Arf for enterovirus replication. These results document the rewiring of the cellular membrane pathways in infected cells and may provide new ways of controlling enterovirus infections.
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16
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Navare AT, Mast FD, Olivier JP, Bertomeu T, Neal M, Carpp LN, Kaushansky A, Coulombe-Huntington J, Tyers M, Aitchison JD. Viral protein engagement of GBF1 induces host cell vulnerability through synthetic lethality. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2020; 221:2020.10.12.336487. [PMID: 33173868 PMCID: PMC7654857 DOI: 10.1101/2020.10.12.336487] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Viruses co-opt host proteins to carry out their lifecycle. Repurposed host proteins may thus become functionally compromised; a situation analogous to a loss-of-function mutation. We term such host proteins viral-induced hypomorphs. Cells bearing cancer driver loss-of-function mutations have successfully been targeted with drugs perturbing proteins encoded by the synthetic lethal partners of cancer-specific mutations. Synthetic lethal interactions of viral-induced hypomorphs have the potential to be similarly targeted for the development of host-based antiviral therapeutics. Here, we use GBF1, which supports the infection of many RNA viruses, as a proof-of-concept. GBF1 becomes a hypomorph upon interaction with the poliovirus protein 3A. Screening for synthetic lethal partners of GBF1 revealed ARF1 as the top hit, disruption of which, selectively killed cells that synthesize poliovirus 3A. Thus, viral protein interactions can induce hypomorphs that render host cells vulnerable to perturbations that leave uninfected cells intact. Exploiting viral-induced vulnerabilities could lead to broad-spectrum antivirals for many viruses, including SARS-CoV-2. SUMMARY Using a viral-induced hypomorph of GBF1, Navare et al., demonstrate that the principle of synthetic lethality is a mechanism to selectively kill virus-infected cells.
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Affiliation(s)
- Arti T Navare
- Center for Global Infectious Disease Research, Seattle Children’s Research Institute, Seattle, Washington, USA
| | - Fred D Mast
- Center for Global Infectious Disease Research, Seattle Children’s Research Institute, Seattle, Washington, USA
| | - Jean Paul Olivier
- Center for Global Infectious Disease Research, Seattle Children’s Research Institute, Seattle, Washington, USA
| | - Thierry Bertomeu
- Institute for Research in Immunology and Cancer, Université de Montréal, Montreal, Quebec, Canada
| | - Maxwell Neal
- Center for Global Infectious Disease Research, Seattle Children’s Research Institute, Seattle, Washington, USA
| | - Lindsay N Carpp
- Center for Infectious Disease Research, Seattle, Washington, USA
| | - Alexis Kaushansky
- Center for Global Infectious Disease Research, Seattle Children’s Research Institute, Seattle, Washington, USA
- Department of Pediatrics, University of Washington, Seattle, Washington, USA
| | | | - Mike Tyers
- Institute for Research in Immunology and Cancer, Université de Montréal, Montreal, Quebec, Canada
| | - John D Aitchison
- Center for Global Infectious Disease Research, Seattle Children’s Research Institute, Seattle, Washington, USA
- Department of Pediatrics, University of Washington, Seattle, Washington, USA
- Department of Biochemistry, University of Washington, Seattle, Washington, USA
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17
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Mendoza-Ferreira N, Karakaya M, Cengiz N, Beijer D, Brigatti KW, Gonzaga-Jauregui C, Fuhrmann N, Hölker I, Thelen MP, Zetzsche S, Rombo R, Puffenberger EG, De Jonghe P, Deconinck T, Zuchner S, Strauss KA, Carson V, Schrank B, Wunderlich G, Baets J, Wirth B. De Novo and Inherited Variants in GBF1 are Associated with Axonal Neuropathy Caused by Golgi Fragmentation. Am J Hum Genet 2020; 107:763-777. [PMID: 32937143 PMCID: PMC7491385 DOI: 10.1016/j.ajhg.2020.08.018] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2020] [Accepted: 08/19/2020] [Indexed: 01/18/2023] Open
Abstract
Distal hereditary motor neuropathies (HMNs) and axonal Charcot-Marie-Tooth neuropathy (CMT2) are clinically and genetically heterogeneous diseases characterized primarily by motor neuron degeneration and distal weakness. The genetic cause for about half of the individuals affected by HMN/CMT2 remains unknown. Here, we report the identification of pathogenic variants in GBF1 (Golgi brefeldin A-resistant guanine nucleotide exchange factor 1) in four unrelated families with individuals affected by sporadic or dominant HMN/CMT2. Genomic sequencing analyses in seven affected individuals uncovered four distinct heterozygous GBF1 variants, two of which occurred de novo. Other known HMN/CMT2-implicated genes were excluded. Affected individuals show HMN/CMT2 with slowly progressive distal muscle weakness and musculoskeletal deformities. Electrophysiological studies confirmed axonal damage with chronic neurogenic changes. Three individuals had additional distal sensory loss. GBF1 encodes a guanine-nucleotide exchange factor that facilitates the activation of members of the ARF (ADP-ribosylation factor) family of small GTPases. GBF1 is mainly involved in the formation of coatomer protein complex (COPI) vesicles, maintenance and function of the Golgi apparatus, and mitochondria migration and positioning. We demonstrate that GBF1 is present in mouse spinal cord and muscle tissues and is particularly abundant in neuropathologically relevant sites, such as the motor neuron and the growth cone. Consistent with the described role of GBF1 in Golgi function and maintenance, we observed marked increase in Golgi fragmentation in primary fibroblasts derived from all affected individuals in this study. Our results not only reinforce the existing link between Golgi fragmentation and neurodegeneration but also demonstrate that pathogenic variants in GBF1 are associated with HMN/CMT2.
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18
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Zhao A, Li Y, Niu M, Li G, Luo N, Zhou L, Kang W, Liu J. SNPs in SNCA, MCCC1, DLG2, GBF1 and MBNL2 are associated with Parkinson's disease in southern Chinese population. J Cell Mol Med 2020; 24:8744-8752. [PMID: 32652860 PMCID: PMC7412680 DOI: 10.1111/jcmm.15508] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2019] [Revised: 05/12/2020] [Accepted: 05/29/2020] [Indexed: 01/08/2023] Open
Abstract
Numerous single nucleotide polymorphisms (SNPs), which have been identified as susceptibility factors for Parkinson's disease (PD) as per genome-wide association studies, have not been fully characterized for PD patients in China. This study aimed to replicate the relationship between 12 novel SNPs of 12 genes and PD risk in southern Chinese population. Twelve SNPs of 12 genes were detected in 231 PD patients and 249 controls, using the SNaPshot technique. Meta-analysis was used to assess heterogeneity of effect sizes between this study and published data. The impact of SNPs on gene expression was investigated by analysing the SNP-gene association in the expression quantitative trait loci (eQTL) data sets. rs8180209 of SNCA (allele model: P = .047, OR = 0.77; additive model: P = .047, OR = 0.77), rs2270968 of MCCC1 (dominant model: P = .024, OR = 1.52), rs7479949 of DLG2 (recessive model; P = .019, OR = 1.52), rs10748818 of GBF1 (additive model: P < .001, OR = 0.37), and rs4771268 of MBNL2 (recessive model: P = .003, OR = 0.48) were replicated to be significantly associated with the increased risk of PD. Noteworthy, a meta-analysis of previous studies suggested rs8180209, rs2270968, rs7479949 and rs4771268 were in line with those of our cohort. Our study replicated five novel functional SNPs in SNCA, MCCC1, DLG2, GBF1 and MBNL2 could be associated with increased risk of PD in southern Chinese population.
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Affiliation(s)
- Aonan Zhao
- Department of Neurology and Institute of Neurology, Ruijin Hospital Affiliated with the Shanghai Jiaotong University School of Medicine, Shanghai, China
| | - Yuanyuan Li
- Department of Neurology and Institute of Neurology, Ruijin Hospital Affiliated with the Shanghai Jiaotong University School of Medicine, Shanghai, China
| | - Mengyue Niu
- Department of Neurology and Institute of Neurology, Ruijin Hospital Affiliated with the Shanghai Jiaotong University School of Medicine, Shanghai, China
| | - Guanglu Li
- Department of Neurology and Institute of Neurology, Ruijin Hospital Affiliated with the Shanghai Jiaotong University School of Medicine, Shanghai, China
| | - Ningdi Luo
- Department of Neurology and Institute of Neurology, Ruijin Hospital Affiliated with the Shanghai Jiaotong University School of Medicine, Shanghai, China
| | - Liche Zhou
- Department of Neurology and Institute of Neurology, Ruijin Hospital Affiliated with the Shanghai Jiaotong University School of Medicine, Shanghai, China
| | - Wenyan Kang
- Department of Neurology, Ruijin Hospital North Affiliated to Shanghai Jiaotong University School of Medicine, Shanghai, China
| | - Jun Liu
- Department of Neurology and Institute of Neurology, Ruijin Hospital Affiliated with the Shanghai Jiaotong University School of Medicine, Shanghai, China.,Department of Neurology, Ruijin Hospital North Affiliated to Shanghai Jiaotong University School of Medicine, Shanghai, China.,CAS Center for Excellence in Brain Science and Intelligence Technology, Ruijin Hospital Affiliated to Shanghai Jiaotong University School of Medicine, Shanghai, China.,Department of Neurology, RuiJin Hospital/Lu Wan Branch, School of Medicine, Shanghai Jiaotong University, Shanghai, China
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19
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Walton K, Leier A, Sztul E. Regulating the regulators: role of phosphorylation in modulating the function of the GBF1/BIG family of Sec7 ARF-GEFs. FEBS Lett 2020; 594:2213-2226. [PMID: 32333796 DOI: 10.1002/1873-3468.13798] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2020] [Revised: 04/15/2020] [Accepted: 04/16/2020] [Indexed: 12/15/2022]
Abstract
Membrane traffic between secretory and endosomal compartments is vesicle-mediated and must be tightly balanced to maintain a physiological compartment size. Vesicle formation is initiated by guanine nucleotide exchange factors (GEFs) that activate the ARF family of small GTPases. Regulatory mechanisms, including reversible phosphorylation, allow ARF-GEFs to support vesicle formation only at the right time and place in response to cellular needs. Here, we review current knowledge of how the Golgi-specific brefeldin A-resistance factor 1 (GBF1)/brefeldin A-inhibited guanine nucleotide exchange protein (BIG) family of ARF-GEFs is influenced by phosphorylation and use predictive paradigms to propose new regulatory paradigms. We describe a conserved cluster of phosphorylation sites within the N-terminal domains of the GBF1/BIG ARF-GEFs and suggest that these sites may respond to homeostatic signals related to cell growth and division. In the C-terminal region, GBF1 shows phosphorylation sites clustered differently as compared with the similar configuration found in both BIG1 and BIG2. Despite this similarity, BIG1 and BIG2 phosphorylation patterns are divergent in other domains. The different clustering of phosphorylation sites suggests that the nonconserved sites may represent distinct regulatory nodes and specify the function of GBF1, BIG1, and BIG2.
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Affiliation(s)
- Kendall Walton
- Department of Cell, Developmental, and Integrative Biology, University of Alabama at Birmingham, AL, USA
| | - Andre Leier
- Department of Genetics, University of Alabama at Birmingham, AL, USA
| | - Elizabeth Sztul
- Department of Cell, Developmental, and Integrative Biology, University of Alabama at Birmingham, AL, USA
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20
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Uckeley ZM, Moeller R, Kühn LI, Nilsson E, Robens C, Lasswitz L, Lindqvist R, Lenman A, Passos V, Voss Y, Sommerauer C, Kampmann M, Goffinet C, Meissner F, Överby AK, Lozach PY, Gerold G. Quantitative Proteomics of Uukuniemi Virus-host Cell Interactions Reveals GBF1 as Proviral Host Factor for Phleboviruses. Mol Cell Proteomics 2019; 18:2401-2417. [PMID: 31570497 PMCID: PMC6885706 DOI: 10.1074/mcp.ra119.001631] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2019] [Revised: 09/15/2019] [Indexed: 12/20/2022] Open
Abstract
Novel tick-borne phleboviruses in the Phenuiviridae family, which are highly pathogenic in humans and all closely related to Uukuniemi virus (UUKV), have recently emerged on different continents. How phleboviruses assemble, bud, and exit cells remains largely elusive. Here, we performed high-resolution, label-free mass spectrometry analysis of UUKV immunoprecipitated from cell lysates and identified 39 cellular partners interacting with the viral envelope glycoproteins. The importance of these host factors for UUKV infection was validated by silencing each host factor by RNA interference. This revealed Golgi-specific brefeldin A-resistance guanine nucleotide exchange factor 1 (GBF1), a guanine nucleotide exchange factor resident in the Golgi, as a critical host factor required for the UUKV life cycle. An inhibitor of GBF1, Golgicide A, confirmed the role of the cellular factor in UUKV infection. We could pinpoint the GBF1 requirement to UUKV replication and particle assembly. When the investigation was extended to viruses from various positive and negative RNA viral families, we found that not only phleboviruses rely on GBF1 for infection, but also Flavi-, Corona-, Rhabdo-, and Togaviridae In contrast, silencing or blocking GBF1 did not abrogate infection by the human adenovirus serotype 5 and immunodeficiency retrovirus type 1, the replication of both requires nuclear steps. Together our results indicate that UUKV relies on GBF1 for viral replication, assembly and egress. This study also highlights the proviral activity of GBF1 in the infection by a broad range of important zoonotic RNA viruses.
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Affiliation(s)
- Zina M Uckeley
- CellNetworks Cluster of Excellence and Department of Infectious Diseases, Virology, University Hospital Heidelberg, Heidelberg, Germany; CellNetworks Cluster of Excellence and Department of Infectious Diseases, Virology, University Hospital Heidelberg, Heidelberg, Germany
| | - Rebecca Moeller
- Institute for Experimental Virology, TWINCORE, Centre for Experimental and Clinical Infection Research, a joint venture between the Medical School Hannover and the Helmholtz Centre for Infection Research, Hannover, Germany; CellNetworks Cluster of Excellence and Department of Infectious Diseases, Virology, University Hospital Heidelberg, Heidelberg, Germany
| | - Lars I Kühn
- Experimental Systems Immunology, Max Planck Institute of Biochemistry, Martinsried, Germany
| | - Emma Nilsson
- Division of Virology, Department of Clinical Microbiology, and Laboratory for Molecular Infection Medicine Sweden, Umeå University, Umeå, Sweden
| | - Claudia Robens
- CellNetworks Cluster of Excellence and Department of Infectious Diseases, Virology, University Hospital Heidelberg, Heidelberg, Germany
| | - Lisa Lasswitz
- Institute for Experimental Virology, TWINCORE, Centre for Experimental and Clinical Infection Research, a joint venture between the Medical School Hannover and the Helmholtz Centre for Infection Research, Hannover, Germany
| | - Richard Lindqvist
- Division of Virology, Department of Clinical Microbiology, and Laboratory for Molecular Infection Medicine Sweden, Umeå University, Umeå, Sweden
| | - Annasara Lenman
- Institute for Experimental Virology, TWINCORE, Centre for Experimental and Clinical Infection Research, a joint venture between the Medical School Hannover and the Helmholtz Centre for Infection Research, Hannover, Germany
| | - Vania Passos
- Institute for Experimental Virology, TWINCORE, Centre for Experimental and Clinical Infection Research, a joint venture between the Medical School Hannover and the Helmholtz Centre for Infection Research, Hannover, Germany; Instituto De Ciências Biomédicas Abel Salazar, Universidade Do Porto, Porto, Portugal
| | - Yannik Voss
- CellNetworks Cluster of Excellence and Department of Infectious Diseases, Virology, University Hospital Heidelberg, Heidelberg, Germany
| | - Christian Sommerauer
- CellNetworks Cluster of Excellence and Department of Infectious Diseases, Virology, University Hospital Heidelberg, Heidelberg, Germany
| | - Martin Kampmann
- CellNetworks Cluster of Excellence and Department of Infectious Diseases, Virology, University Hospital Heidelberg, Heidelberg, Germany
| | - Christine Goffinet
- Institute for Experimental Virology, TWINCORE, Centre for Experimental and Clinical Infection Research, a joint venture between the Medical School Hannover and the Helmholtz Centre for Infection Research, Hannover, Germany; Institute of Virology, Charité, Universitätsmedizin Berlin, Berlin, Germany and Berlin Institute of Health (BIH), Berlin, Germany
| | - Felix Meissner
- Experimental Systems Immunology, Max Planck Institute of Biochemistry, Martinsried, Germany
| | - Anna K Överby
- Division of Virology, Department of Clinical Microbiology, and Laboratory for Molecular Infection Medicine Sweden, Umeå University, Umeå, Sweden
| | - Pierre-Yves Lozach
- CellNetworks Cluster of Excellence and Department of Infectious Diseases, Virology, University Hospital Heidelberg, Heidelberg, Germany; IVPC UMR754, INRA, Univ. Lyon, EPHE, 50 Av. Tony Garnier, 69007 Lyon, France.
| | - Gisa Gerold
- Institute for Experimental Virology, TWINCORE, Centre for Experimental and Clinical Infection Research, a joint venture between the Medical School Hannover and the Helmholtz Centre for Infection Research, Hannover, Germany; Department of Clinical Microbiology, Virology & Wallenberg Centre for Molecular Medicine (WCMM), Umeå University, SE-90185 Umeå, Sweden.
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21
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Raphemot R, Toro-Moreno M, Lu KY, Posfai D, Derbyshire ER. Discovery of Druggable Host Factors Critical to Plasmodium Liver-Stage Infection. Cell Chem Biol 2019; 26:1253-1262.e5. [PMID: 31257182 DOI: 10.1016/j.chembiol.2019.05.011] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2018] [Revised: 04/06/2019] [Accepted: 05/22/2019] [Indexed: 11/26/2022]
Abstract
Plasmodium parasites undergo an obligatory and asymptomatic developmental stage within the liver before infecting red blood cells to cause malaria. The hijacked host pathways critical to parasite infection during this hepatic phase remain poorly understood. Here, we implemented a forward genetic screen to identify over 100 host factors within the human druggable genome that are critical to P. berghei infection in hepatoma cells. Notably, we found knockdown of genes involved in protein trafficking pathways to be detrimental to parasite infection. The disruption of protein trafficking modulators, including COPB2 and GGA1, decreases P. berghei parasite size, and an immunofluorescence study suggests that these proteins are recruited to the Plasmodium parasitophorous vacuole in infected hepatocytes. These findings reveal that various host intracellular protein trafficking pathways are subverted by Plasmodium parasites during the liver stage and provide new insights into their manipulation for growth and development.
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Affiliation(s)
- Rene Raphemot
- Department of Chemistry, Duke University, 124 Science Drive, Durham, NC 27708, USA
| | - Maria Toro-Moreno
- Department of Chemistry, Duke University, 124 Science Drive, Durham, NC 27708, USA
| | - Kuan-Yi Lu
- Department of Molecular Genetics and Microbiology, Duke University Medical Center, 213 Research Drive, Durham, NC 27710, USA
| | - Dora Posfai
- Department of Molecular Genetics and Microbiology, Duke University Medical Center, 213 Research Drive, Durham, NC 27710, USA
| | - Emily Rose Derbyshire
- Department of Chemistry, Duke University, 124 Science Drive, Durham, NC 27708, USA; Department of Molecular Genetics and Microbiology, Duke University Medical Center, 213 Research Drive, Durham, NC 27710, USA.
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22
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Regulatory role of Golgi brefeldin A resistance factor‐1 in amyloid precursor protein trafficking, cleavage and Aβ formation. J Cell Biochem 2019; 120:15604-15615. [DOI: 10.1002/jcb.28827] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2018] [Revised: 01/11/2019] [Accepted: 01/14/2019] [Indexed: 01/19/2023]
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23
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Deretic D, Lorentzen E, Fresquez T. The ins and outs of the Arf4-based ciliary membrane-targeting complex. Small GTPases 2019; 12:1-12. [PMID: 31068062 DOI: 10.1080/21541248.2019.1616355] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022] Open
Abstract
The small GTPase Arf4-based ciliary membrane-targeting complex recognizes specific targeting signals within sensory receptors and regulates their directed movement to primary cilia. Activated Arf4 directly binds the VxPx ciliary-targeting signal (CTS) of the light-sensing receptor rhodopsin. Recent findings revealed that at the trans-Golgi, marked by the small GTPase Rab6, activated Arf4 forms a functional complex with rhodopsin and the Arf guanine nucleotide exchange factor (GEF) GBF1, providing positive feedback that drives further Arf4 activation in ciliary trafficking. Arf4 function is conserved across diverse cell types; however, it appears that not all its aspects are conserved across species, as mouse Arf4 is a natural mutant in the conserved α3 helix, which is essential for its interaction with rhodopsin. Generally, activated Arf4 regulates the assembly of the targeting nexus containing the Arf GAP ASAP1 and the Rab11a-FIP3-Rabin8 dual effector complex, which controls the assembly of the highly conserved Rab11a-Rabin8-Rab8 ciliary-targeting module. It was recently found that this module interacts with the R-SNARE VAMP7, likely in its activated, c-Src-phosphorylated form. Rab11 and Rab8 bind VAMP7 regulatory longin domain (LD), whereas Rabin8 interacts with the SNARE domain, capturing VAMP7 for delivery to the ciliary base and subsequent pairing with the cognate SNAREs syntaxin 3 and SNAP-25. This review will focus on the implications of these novel findings that further illuminate the role of well-ordered Arf and Rab interaction networks in targeting of sensory receptors to primary cilia. Abbreviations: CTS: Ciliary-Targeting Signal; GAP: GTPase Activating Protein; GEF: Guanine Nucleotide Exchange Factor; RTC(s), Rhodopsin Transport Carrier(s); SNARE: Soluble N-ethylmaleimide-sensitive Factor Attachment Protein Receptor; TGN: Trans-Golgi Network.
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Affiliation(s)
- Dusanka Deretic
- Departments of Surgery, Division of Ophthalmology, University of New Mexico , Albuquerque, NM, USA.,Cell Biology and Physiology, University of New Mexico , Albuquerque, NM, USA
| | - Esben Lorentzen
- Department of Molecular Biology and Genetics, Aarhus University , Aarhus, Denmark
| | - Theresa Fresquez
- Departments of Surgery, Division of Ophthalmology, University of New Mexico , Albuquerque, NM, USA
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24
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Lopes-da-Silva M, McCormack JJ, Burden JJ, Harrison-Lavoie KJ, Ferraro F, Cutler DF. A GBF1-Dependent Mechanism for Environmentally Responsive Regulation of ER-Golgi Transport. Dev Cell 2019; 49:786-801.e6. [PMID: 31056345 PMCID: PMC6764485 DOI: 10.1016/j.devcel.2019.04.006] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2018] [Revised: 02/19/2019] [Accepted: 04/04/2019] [Indexed: 12/17/2022]
Abstract
How can anterograde membrane trafficking be modulated by physiological cues? A screen of Golgi-associated proteins revealed that the ARF-GEF GBF1 can selectively modulate the ER-Golgi trafficking of prohaemostatic von Willebrand factor (VWF) and extracellular matrix (ECM) proteins in human endothelial cells and in mouse fibroblasts. The relationship between levels of GBF1 and the trafficking of VWF into forming secretory granules confirmed GBF1 is a limiting factor in this process. Further, GBF1 activation by AMPK couples its control of anterograde trafficking to physiological cues; levels of glucose control GBF1 activation in turn modulating VWF trafficking into secretory granules. GBF1 modulates both ER and TGN exit, the latter dramatically affecting the size of the VWF storage organelles, thereby influencing the hemostatic capacity of the endothelium. The role of AMPK as a central integrating element of cellular pathways with intra- and extra-cellular cues can now be extended to modulation of the anterograde secretory pathway. The Arf-GEF GBF1 modulates anterograde trafficking of VWF and ECM proteins Loss of GBF1 slows ER and TGN exit, producing swollen ER and giant WPBs Activation of GBF1 via AMPK reduces endothelial WPB size and secretion Metabolic change alters anterograde trafficking and cargo secretion via AMPK-GBF1
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Affiliation(s)
- Mafalda Lopes-da-Silva
- Endothelial Cell Biology Laboratory, MRC Laboratory for Molecular Cell Biology, University College London, London, UK.
| | - Jessica J McCormack
- Endothelial Cell Biology Laboratory, MRC Laboratory for Molecular Cell Biology, University College London, London, UK
| | - Jemima J Burden
- Electron Microscopy Laboratory, MRC Laboratory for Molecular Cell Biology, University College London, London, UK
| | - Kimberly J Harrison-Lavoie
- Endothelial Cell Biology Laboratory, MRC Laboratory for Molecular Cell Biology, University College London, London, UK
| | - Francesco Ferraro
- Endothelial Cell Biology Laboratory, MRC Laboratory for Molecular Cell Biology, University College London, London, UK
| | - Daniel F Cutler
- Endothelial Cell Biology Laboratory, MRC Laboratory for Molecular Cell Biology, University College London, London, UK.
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25
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Bhatt JM, Hancock W, Meissner JM, Kaczmarczyk A, Lee E, Viktorova E, Ramanadham S, Belov GA, Sztul E. Promiscuity of the catalytic Sec7 domain within the guanine nucleotide exchange factor GBF1 in ARF activation, Golgi homeostasis, and effector recruitment. Mol Biol Cell 2019; 30:1523-1535. [PMID: 30943106 PMCID: PMC6724685 DOI: 10.1091/mbc.e18-11-0711] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
The integrity of the Golgi and trans-Golgi network (TGN) is disrupted by brefeldin A (BFA), which inhibits the Golgi-localized BFA-sensitive factor (GBF1) and brefeldin A-inhibited guanine nucleotide-exchange factors (BIG1 and BIG2). Using a cellular replacement assay to assess GBF1 functionality without interference from the BIGs, we show that GBF1 alone maintains Golgi architecture; facilitates secretion; activates ADP-ribosylation factor (ARF)1, 3, 4, and 5; and recruits ARF effectors to Golgi membranes. Unexpectedly, GBF1 also supports TGN integrity and recruits numerous TGN-localized ARF effectors. The impact of the catalytic Sec7 domain (Sec7d) on GBF1 functionality was assessed by swapping it with the Sec7d from ARF nucleotide-binding site opener (ARNO)/cytohesin-2, a plasma membrane GEF reported to activate all ARFs. The resulting chimera (GBF1-ARNO-GBF1 [GARG]) targets like GBF1, supports Golgi/TGN architecture, and facilitates secretion. However, unlike GBF1, GARG activates all ARFs (including ARF6) at the Golgi/TGN and recruits additional ARF effectors to the Golgi/TGN. Our results have general implications: 1) GEF's targeting is independent of Sec7d, but Sec7d influence the GEF substrate specificity and downstream effector events; 2) all ARFs have access to all membranes, but are restricted in their distribution by the localization of their activating GEFs; and 3) effector association with membranes requires the coincidental presence of activated ARFs and specific membrane identifiers.
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Affiliation(s)
- Jay M Bhatt
- Department of Cell, Developmental and Integrative Biology, University of Alabama at Birmingham, Birmingham, AL 35294
| | - William Hancock
- Department of Cell, Developmental and Integrative Biology, University of Alabama at Birmingham, Birmingham, AL 35294
| | - Justyna M Meissner
- Department of Cell, Developmental and Integrative Biology, University of Alabama at Birmingham, Birmingham, AL 35294
| | - Aneta Kaczmarczyk
- Department of Cell, Developmental and Integrative Biology, University of Alabama at Birmingham, Birmingham, AL 35294
| | - Eunjoo Lee
- Department of Cell, Developmental and Integrative Biology, University of Alabama at Birmingham, Birmingham, AL 35294
| | - Ekaterina Viktorova
- Department of Veterinary Medicine, Virginia-Maryland Regional College of Veterinary Medicine, University of Maryland, College Park, MD 20742
| | - Sasanka Ramanadham
- Department of Cell, Developmental and Integrative Biology, University of Alabama at Birmingham, Birmingham, AL 35294.,Comprehensive Diabetes Center, University of Alabama at Birmingham, Birmingham, AL 35294
| | - George A Belov
- Department of Veterinary Medicine, Virginia-Maryland Regional College of Veterinary Medicine, University of Maryland, College Park, MD 20742
| | - Elizabeth Sztul
- Department of Cell, Developmental and Integrative Biology, University of Alabama at Birmingham, Birmingham, AL 35294
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26
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Park JS, Helble JD, Lazarus JE, Yang G, Blondel CJ, Doench JG, Starnbach MN, Waldor MK. A FACS-Based Genome-wide CRISPR Screen Reveals a Requirement for COPI in Chlamydia trachomatis Invasion. iScience 2018; 11:71-84. [PMID: 30590252 PMCID: PMC6308251 DOI: 10.1016/j.isci.2018.12.011] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2018] [Revised: 09/20/2018] [Accepted: 12/10/2018] [Indexed: 12/26/2022] Open
Abstract
The invasion of Chlamydia trachomatis, an obligate intracellular bacterium, into epithelial cells is driven by a complex interplay of host and bacterial factors. To comprehensively define the host genes required for pathogen invasion, we undertook a fluorescence-activated cell sorting (FACS)-based CRISPR screen in human cells. A genome-wide loss-of-function library was infected with fluorescent C. trachomatis and then sorted to enrich for invasion-deficient mutants. The screen identified heparan sulfate, a known pathogen receptor, as well as coatomer complex I (COPI). We found that COPI, through a previously unappreciated role, promotes heparan sulfate cell surface presentation, thereby facilitating C. trachomatis attachment. The heparan sulfate defect does not fully account for the resistance of COPI mutants. COPI also promotes the activity of the pathogen's type III secretion system. Together, our findings establish the requirement for COPI in C. trachomatis invasion and the utility of FACS-based CRISPR screening for the elucidation of host factors required for pathogen invasion. FACS-based CRISPR screen to identify host factors required for C. trachomatis invasion Candidate genes comprise heparan sulfate biosynthesis, actin remodeling, and COPI COPI regulates heparan sulfate cell surface presentation and C. trachomatis attachment COPI is also required for efficient C. trachomatis T3SS translocation
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Affiliation(s)
- Joseph S Park
- Howard Hughes Medical Institute, Boston, MA 02215, USA; Department of Microbiology and Immunobiology, Harvard Medical School, Boston, MA 02115, USA; Division of Infectious Diseases, Brigham & Women's Hospital, Boston 02115, MA, USA; Boston University School of Medicine, Boston, MA 02120, USA
| | - Jennifer D Helble
- Department of Microbiology and Immunobiology, Harvard Medical School, Boston, MA 02115, USA
| | - Jacob E Lazarus
- Department of Microbiology and Immunobiology, Harvard Medical School, Boston, MA 02115, USA; Division of Infectious Diseases, Brigham & Women's Hospital, Boston 02115, MA, USA; Division of Infectious Diseases, Massachusetts General Hospital, Boston, MA 02114, USA
| | - Guanhua Yang
- Division of Infectious Diseases, Brigham & Women's Hospital, Boston 02115, MA, USA
| | - Carlos J Blondel
- Division of Infectious Diseases, Brigham & Women's Hospital, Boston 02115, MA, USA
| | - John G Doench
- Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA
| | - Michael N Starnbach
- Department of Microbiology and Immunobiology, Harvard Medical School, Boston, MA 02115, USA
| | - Matthew K Waldor
- Howard Hughes Medical Institute, Boston, MA 02215, USA; Department of Microbiology and Immunobiology, Harvard Medical School, Boston, MA 02115, USA; Division of Infectious Diseases, Brigham & Women's Hospital, Boston 02115, MA, USA; Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA.
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27
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Luchsinger C, Aguilar M, Burgos PV, Ehrenfeld P, Mardones GA. Functional disruption of the Golgi apparatus protein ARF1 sensitizes MDA-MB-231 breast cancer cells to the antitumor drugs Actinomycin D and Vinblastine through ERK and AKT signaling. PLoS One 2018; 13:e0195401. [PMID: 29614107 PMCID: PMC5882166 DOI: 10.1371/journal.pone.0195401] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2017] [Accepted: 03/21/2018] [Indexed: 12/26/2022] Open
Abstract
Increasing evidence indicates that the Golgi apparatus plays active roles in cancer, but a comprehensive understanding of its functions in the oncogenic transformation has not yet emerged. At the same time, the Golgi is becoming well recognized as a hub that integrates its functions of protein and lipid biosynthesis to signal transduction for cell proliferation and migration in cancer cells. Nevertheless, the active function of the Golgi apparatus in cancer cells has not been fully evaluated as a target for combined treatment. Here, we analyzed the effect of perturbing the Golgi apparatus on the sensitivity of the MDA-MB-231 breast cancer cell line to the drugs Actinomycin D and Vinblastine. We disrupted the function of ARF1, a protein necessary for the homeostasis of the Golgi apparatus. We found that the expression of the ARF1-Q71L mutant increased the sensitivity of MDA-MB-231 cells to both Actinomycin D and Vinblastine, resulting in decreased cell proliferation and cell migration, as well as in increased apoptosis. Likewise, the combined treatment of cells with Actinomycin D or Vinblastine and Brefeldin A or Golgicide A, two disrupting agents of the ARF1 function, resulted in similar effects on cell proliferation, cell migration and apoptosis. Interestingly, each combined treatment had distinct effects on ERK1/2 and AKT signaling, as indicated by the decreased levels of either phospho-ERK1/2 or phospho-AKT. Our results suggest that disruption of Golgi function could be used as a strategy for the sensitization of cancer cells to chemotherapy.
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Affiliation(s)
- Charlotte Luchsinger
- Department of Physiology, School of Medicine, Universidad Austral de Chile, Valdivia, Chile
- Center for Interdisciplinary Studies of the Nervous System (CISNe), Universidad Austral de Chile, Valdivia, Chile
| | - Marcelo Aguilar
- Department of Physiology, School of Medicine, Universidad Austral de Chile, Valdivia, Chile
- Center for Interdisciplinary Studies of the Nervous System (CISNe), Universidad Austral de Chile, Valdivia, Chile
| | - Patricia V. Burgos
- Department of Physiology, School of Medicine, Universidad Austral de Chile, Valdivia, Chile
- Center for Interdisciplinary Studies of the Nervous System (CISNe), Universidad Austral de Chile, Valdivia, Chile
- Center for Cell Biology and Biomedicine (CEBICEM), School of Medicine and Science, Universidad San Sebastián, Santiago, Chile
- Center for Aging and Regeneration (CARE), Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Pamela Ehrenfeld
- Center for Interdisciplinary Studies of the Nervous System (CISNe), Universidad Austral de Chile, Valdivia, Chile
- Department of Anatomy, Histology and Pathology, School of Medicine, Universidad Austral de Chile, Valdivia, Chile
| | - Gonzalo A. Mardones
- Department of Physiology, School of Medicine, Universidad Austral de Chile, Valdivia, Chile
- Center for Interdisciplinary Studies of the Nervous System (CISNe), Universidad Austral de Chile, Valdivia, Chile
- Center for Cell Biology and Biomedicine (CEBICEM), School of Medicine and Science, Universidad San Sebastián, Santiago, Chile
- * E-mail:
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28
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Pocognoni CA, Viktorova EG, Wright J, Meissner JM, Sager G, Lee E, Belov GA, Sztul E. Highly conserved motifs within the large Sec7 ARF guanine nucleotide exchange factor GBF1 target it to the Golgi and are critical for GBF1 activity. Am J Physiol Cell Physiol 2018; 314:C675-C689. [PMID: 29443553 DOI: 10.1152/ajpcell.00221.2017] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Cellular life requires the activation of the ADP-ribosylation factors (ARFs) by Golgi brefeldin A-resistant factor 1 (GBF1), a guanine nucleotide exchange factor (GEF) with a highly conserved catalytic Sec7 domain (Sec7d). In addition to the Sec7d, GBF1 contains other conserved domains whose functions remain unclear. Here, we focus on HDS2 (homology downstream of Sec7d 2) domain because the L1246R substitution within the HDS2 α-helix 5 of the zebrafish GBF1 ortholog causes vascular hemorrhaging and embryonic lethality (13). To dissect the structure/function relationships within HDS2, we generated six variants, in which the most conserved residues within α-helices 1, 2, 4, and 6 were mutated to alanines. Each HDS2 mutant was assessed in a cell-based "replacement" assay for its ability to support cellular functions normally supported by GBF1, such as maintaining Golgi homeostasis, facilitating COPI recruitment, supporting secretion, and sustaining cellular viability. We show that cells treated with the pharmacological GBF1 inhibitor brefeldin A (BFA) and expressing a BFA-resistant GBF1 variant with alanine substitutions of RDR1168 or LF1266 are compromised in Golgi homeostasis, impaired in ARF activation, unable to sustain secretion, and defective in maintaining cellular viability. To gain insight into the molecular mechanism of this dysfunction, we assessed the ability of each GBF1 mutant to target to Golgi membranes and found that mutations in RDR1168 and LF1266 significantly decrease targeting efficiency. Thus, these residues within α-helix 2 and α-helix 6 of the HDS2 domain in GBF1 are novel regulatory determinants that support GBF1 cellular function by impacting the Golgi-specific membrane association of GBF1.
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Affiliation(s)
- Cristian A Pocognoni
- Department of Cell, Developmental and Integrative Biology, University of Alabama at Birmingham , Birmingham, Alabama
| | - Ekaterina G Viktorova
- Department of Veterinary Medicine, Virginia-Maryland Regional College of Veterinary Medicine, University of Maryland , College Park, Maryland
| | - John Wright
- Department of Cell, Developmental and Integrative Biology, University of Alabama at Birmingham , Birmingham, Alabama
| | - Justyna M Meissner
- Department of Cell, Developmental and Integrative Biology, University of Alabama at Birmingham , Birmingham, Alabama
| | - Garrett Sager
- Department of Cell, Developmental and Integrative Biology, University of Alabama at Birmingham , Birmingham, Alabama
| | - Eunjoo Lee
- Department of Cell, Developmental and Integrative Biology, University of Alabama at Birmingham , Birmingham, Alabama
| | - George A Belov
- Department of Veterinary Medicine, Virginia-Maryland Regional College of Veterinary Medicine, University of Maryland , College Park, Maryland
| | - Elizabeth Sztul
- Department of Cell, Developmental and Integrative Biology, University of Alabama at Birmingham , Birmingham, Alabama
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29
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Meissner JM, Bhatt JM, Lee E, Styers ML, Ivanova AA, Kahn RA, Sztul E. The ARF guanine nucleotide exchange factor GBF1 is targeted to Golgi membranes through a PIP-binding domain. J Cell Sci 2018; 131:jcs.210245. [PMID: 29361542 DOI: 10.1242/jcs.210245] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2017] [Accepted: 12/15/2017] [Indexed: 11/20/2022] Open
Abstract
ADP-ribosylation factors (ARF) GTPases are activated by guanine nucleotide exchange factors (GEFs) to support cellular homeostasis. Key to understanding spatio-temporal regulation of ARF signaling is the mechanism of GEF recruitment to membranes. Small GEFs are recruited through phosphoinositide (PIP) binding by a pleckstrin homology (PH) domain downstream from the catalytic Sec7 domain (Sec7d). The large GEFs lack PH domains, and their recruitment mechanisms are poorly understood. We probed Golgi recruitment of GBF1, a GEF catalyzing ARF activation required for Golgi homeostasis. We show that the homology downstream of Sec7d-1 (HDS1) regulates Golgi recruitment of GBF1. We document that GBF1 binds phosphoinositides, preferentially PI3P, PI4P and PI(4,5)P2, and that lipid binding requires the HDS1 domain. Mutations within HDS1 that reduce GBF1 binding to specific PIPs in vitro inhibit GBF1 targeting to Golgi membranes in cells. Our data imply that HDS1 and PH domains are functionally analogous in that each uses lipid-based membrane information to regulate GEF recruitment. Lipid-based recruitment of GBF1 extends the paradigm of lipid regulation to small and large GEFs and suggests that lipid-based mechanisms evolved early during GEF diversification. This article has an associated First Person interview with the first author of the paper.
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Affiliation(s)
- Justyna M Meissner
- Department of Cell, Developmental and Integrative Biology, University of Alabama at Birmingham, Birmingham, AL 35294, USA
| | - Jay M Bhatt
- Department of Cell, Developmental and Integrative Biology, University of Alabama at Birmingham, Birmingham, AL 35294, USA
| | - Eunjoo Lee
- Department of Cell, Developmental and Integrative Biology, University of Alabama at Birmingham, Birmingham, AL 35294, USA
| | - Melanie L Styers
- Department of Biology, Birmingham-Southern College, Birmingham, AL 35254, USA
| | - Anna A Ivanova
- Department of Biochemistry, Emory University School of Medicine, Atlanta, GA 30322, USA
| | - Richard A Kahn
- Department of Biochemistry, Emory University School of Medicine, Atlanta, GA 30322, USA
| | - Elizabeth Sztul
- Department of Cell, Developmental and Integrative Biology, University of Alabama at Birmingham, Birmingham, AL 35294, USA
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30
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Kaczmarek B, Verbavatz JM, Jackson CL. GBF1 and Arf1 function in vesicular trafficking, lipid homoeostasis and organelle dynamics. Biol Cell 2017; 109:391-399. [PMID: 28985001 DOI: 10.1111/boc.201700042] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2017] [Revised: 09/22/2017] [Accepted: 09/25/2017] [Indexed: 01/07/2023]
Abstract
The ADP-ribosylation factor (Arf) small G proteins act as molecular switches to coordinate multiple downstream pathways that regulate membrane dynamics. Their activation is spatially and temporally controlled by the guanine nucleotide exchange factors (GEFs). Members of the evolutionarily conserved GBF/Gea family of Arf GEFs are well known for their roles in formation of coat protein complex I (COPI) vesicles, essential for maintaining the structure and function of the Golgi apparatus. However, studies over the past 10 years have found new functions for these GEFs, along with their substrate Arf1, in lipid droplet metabolism, clathrin-independent endocytosis, signalling at the plasma membrane, mitochondrial dynamics and transport along microtubules. Here, we describe these different functions, focussing in particular on the emerging theme of GFB1 and Arf1 regulation of organelle movement on microtubules.
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Affiliation(s)
- Beata Kaczmarek
- Institut Jacques Monod, CNRS, UMR 7592, Université Paris Diderot, Paris, F-75013, France
| | - Jean-Marc Verbavatz
- Institut Jacques Monod, CNRS, UMR 7592, Université Paris Diderot, Paris, F-75013, France
| | - Catherine L Jackson
- Institut Jacques Monod, CNRS, UMR 7592, Université Paris Diderot, Paris, F-75013, France
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31
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Wang J, Fresquez T, Kandachar V, Deretic D. The Arf GEF GBF1 and Arf4 synergize with the sensory receptor cargo, rhodopsin, to regulate ciliary membrane trafficking. J Cell Sci 2017; 130:3975-3987. [PMID: 29025970 DOI: 10.1242/jcs.205492] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2017] [Accepted: 10/10/2017] [Indexed: 01/05/2023] Open
Abstract
The small GTPase Arf4 and the Arf GTPase-activating protein (GAP) ASAP1 cooperatively sequester sensory receptor cargo into transport carriers targeted to primary cilia, but the input that drives Arf4 activation in this process remains unknown. Here, we show, by using frog retinas and recombinant human proteins, that during the carrier biogenesis from the photoreceptor Golgi/trans-Golgi network (TGN) a functional complex is formed between Arf4, the Arf guanine nucleotide exchange factor (GEF) GBF1 and the light-sensing receptor, rhodopsin. Rhodopsin and Arf4 bind the regulatory N-terminal dimerization and cyclophillin-binding (DCB)-homology upstream of Sec7 (HUS) domain of GBF1. The complex is sensitive to Golgicide A (GCA), a selective inhibitor of GBF1 that accordingly blocks rhodopsin delivery to the cilia, without disrupting the photoreceptor Golgi. The emergence of newly synthesized rhodopsin in the endomembrane system is essential for GBF1-Arf4 complex formation in vivo Notably, GBF1 interacts with the Arf GAP ASAP1 in a GCA-resistant manner. Our findings indicate that converging signals on GBF1 from the influx of cargo into the Golgi/TGN and the feedback from Arf4, combined with input from ASAP1, control Arf4 activation during sensory membrane trafficking to primary cilia.
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Affiliation(s)
- Jing Wang
- Department of Surgery, Division of Ophthalmology, University of New Mexico, Albuquerque, New Mexico 87131, USA
| | - Theresa Fresquez
- Department of Surgery, Division of Ophthalmology, University of New Mexico, Albuquerque, New Mexico 87131, USA
| | - Vasundhara Kandachar
- Department of Surgery, Division of Ophthalmology, University of New Mexico, Albuquerque, New Mexico 87131, USA
| | - Dusanka Deretic
- Department of Surgery, Division of Ophthalmology, University of New Mexico, Albuquerque, New Mexico 87131, USA .,Cell Biology and Physiology, University of New Mexico, Albuquerque, New Mexico 87131, USA
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Ignashkova TI, Gendarme M, Peschk K, Eggenweiler HM, Lindemann RK, Reiling JH. Cell survival and protein secretion associated with Golgi integrity in response to Golgi stress-inducing agents. Traffic 2017; 18:530-544. [PMID: 28485883 DOI: 10.1111/tra.12493] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2017] [Revised: 05/05/2017] [Accepted: 05/05/2017] [Indexed: 12/29/2022]
Abstract
The Golgi apparatus is part of the secretory pathway and of central importance for modification, transport and sorting of proteins and lipids. ADP-ribosylation factors, whose activation can be blocked by brefeldin A (BFA), play a major role in functioning of the Golgi network and regulation of membrane traffic and are also involved in proliferation and migration of cancer cells. Due to high cytotoxicity and poor bioavailability, BFA has not passed the preclinical stage of drug development. Recently, AMF-26 and golgicide A have been described as novel inhibitors of the Golgi system with antitumor or bactericidal properties. We provide here further evidence that AMF-26 closely mirrors the mode of action of BFA but is less potent. Using several human cancer cell lines, we studied the effects of AMF-26, BFA and golgicide A on cell homeostasis including Golgi structure, endoplasmic reticulum (ER) stress markers, secretion and viability, and found overall a significant correlation between these parameters. Furthermore, modulation of ADP-ribosylation factor expression has a profound impact on Golgi organization and survival in response to Golgi stress inducers.
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Affiliation(s)
- Tatiana I Ignashkova
- Metabolism and Signaling in Cancer, BioMed X Innovation Center, Heidelberg, Germany
| | - Mathieu Gendarme
- Metabolism and Signaling in Cancer, BioMed X Innovation Center, Heidelberg, Germany
| | - Katrin Peschk
- Medicinal Chemistry, Merck Biopharma, Merck KGaA, Darmstadt, Germany
| | | | - Ralph K Lindemann
- Translational Innovation Platform Oncology, Merck Biopharma, Merck KGaA, Darmstadt, Germany
| | - Jan H Reiling
- Metabolism and Signaling in Cancer, BioMed X Innovation Center, Heidelberg, Germany
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Hepatitis C virus triggers Golgi fragmentation and autophagy through the immunity-related GTPase M. Proc Natl Acad Sci U S A 2017; 114:E3462-E3471. [PMID: 28389568 DOI: 10.1073/pnas.1616683114] [Citation(s) in RCA: 91] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Positive-stranded RNA viruses, such as hepatitis C virus (HCV), assemble their viral replication complexes by remodeling host intracellular membranes to a membranous web. The precise composition of these replication complexes and the detailed mechanisms by which they are formed are incompletely understood. Here we show that the human immunity-related GTPase M (IRGM), known to contribute to autophagy, plays a previously unrecognized role in this process. We show that IRGM is localized at the Golgi apparatus and regulates the fragmentation of Golgi membranes in response to HCV infection, leading to colocalization of Golgi vesicles with replicating HCV. Our results show that IRGM controls phosphorylation of GBF1, a guanine nucleotide exchange factor for Arf-GTPases, which normally operates in Golgi membrane dynamics and vesicle coating in resting cells. We also find that HCV triggers IRGM-mediated phosphorylation of the early autophagy initiator ULK1, thereby providing mechanistic insight into the role of IRGM in HCV-mediated autophagy. Collectively, our results identify IRGM as a key Golgi-situated regulator that links intracellular membrane remodeling by autophagy and Golgi fragmentation with viral replication.
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Busby T, Meissner JM, Styers ML, Bhatt J, Kaushik A, Hjelmeland AB, Sztul E. The Arf activator GBF1 localizes to plasma membrane sites involved in cell adhesion and motility. CELLULAR LOGISTICS 2017; 7:e1308900. [PMID: 28702273 DOI: 10.1080/21592799.2017.1308900] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/16/2016] [Revised: 02/20/2017] [Accepted: 03/14/2017] [Indexed: 10/24/2022]
Affiliation(s)
- Theodore Busby
- Department of Cell, Developmental and Integrative Biology, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Justyna M Meissner
- Department of Cell, Developmental and Integrative Biology, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Melanie L Styers
- Department of Cell, Developmental and Integrative Biology, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Jay Bhatt
- Department of Cell, Developmental and Integrative Biology, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Akhil Kaushik
- Department of Cell, Developmental and Integrative Biology, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Anita B Hjelmeland
- Department of Cell, Developmental and Integrative Biology, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Elizabeth Sztul
- Department of Cell, Developmental and Integrative Biology, University of Alabama at Birmingham, Birmingham, AL, USA
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Chen J, Wu X, Yao L, Yan L, Zhang L, Qiu J, Liu X, Jia S, Meng A. Impairment of Cargo Transportation Caused by gbf1 Mutation Disrupts Vascular Integrity and Causes Hemorrhage in Zebrafish Embryos. J Biol Chem 2016; 292:2315-2327. [PMID: 28003365 DOI: 10.1074/jbc.m116.767608] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2016] [Revised: 12/19/2016] [Indexed: 12/11/2022] Open
Abstract
ADP-ribosylation factor GTPases are activated by guanine nucleotide exchange factors including Gbf1 (Golgi brefeldin A-resistant factor 1) and play important roles in regulating organelle structure and cargo-selective vesicle trafficking. However, the developmental role of Gbf1 in vertebrates remains elusive. In this study, we report the zebrafish mutant line tsu3994 that arises from N-ethyl-N-nitrosourea (ENU)-mediated mutagenesis and is characterized by prominent intracerebral and trunk hemorrhage. The mutant embryos develop hemorrhage accompanied by fewer pigments and shorter caudal fin at day 2 of development. The hemorrhage phenotype is caused by vascular breakage in a cell autonomous fashion. Positional cloning identifies a T → G nucleotide substitution in the 23rd exon of the gbf1 locus, resulting in a leucine → arginine substitution (L1246R) in the HDS2 domain. The mutant phenotype is mimicked by gbf1 knockouts and morphants, suggesting a nature of loss of function. Experimental results in mammalian cells show that the mutant form Gbf1(L1246R) is unable to be recruited to the Golgi apparatus and fails to activate Arf1 for recruiting COPI complex. The hemorrhage in tsu3994 mutants can be prevented partially and temporally by treating with the endoplasmic reticulum stress/apoptosis inhibitor tauroursodeoxycholic acid or by knocking down the proapoptotic gene baxb Therefore, endothelial endoplasmic reticulum stress and subsequent apoptosis induced by gbf1 deficiency may account for the vascular collapse and hemorrhage.
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Affiliation(s)
- Jing Chen
- From the Laboratory of Molecular Developmental Biology, State Key Laboratory of Membrane Biology, Tsinghua-Peking Center for Life Sciences, School of Life Sciences, Tsinghua University, Beijing 100084, China
| | - Xiaotong Wu
- From the Laboratory of Molecular Developmental Biology, State Key Laboratory of Membrane Biology, Tsinghua-Peking Center for Life Sciences, School of Life Sciences, Tsinghua University, Beijing 100084, China
| | - Likun Yao
- From the Laboratory of Molecular Developmental Biology, State Key Laboratory of Membrane Biology, Tsinghua-Peking Center for Life Sciences, School of Life Sciences, Tsinghua University, Beijing 100084, China
| | - Lu Yan
- From the Laboratory of Molecular Developmental Biology, State Key Laboratory of Membrane Biology, Tsinghua-Peking Center for Life Sciences, School of Life Sciences, Tsinghua University, Beijing 100084, China
| | - Lin Zhang
- From the Laboratory of Molecular Developmental Biology, State Key Laboratory of Membrane Biology, Tsinghua-Peking Center for Life Sciences, School of Life Sciences, Tsinghua University, Beijing 100084, China
| | - Juhui Qiu
- From the Laboratory of Molecular Developmental Biology, State Key Laboratory of Membrane Biology, Tsinghua-Peking Center for Life Sciences, School of Life Sciences, Tsinghua University, Beijing 100084, China
| | - Xingfeng Liu
- From the Laboratory of Molecular Developmental Biology, State Key Laboratory of Membrane Biology, Tsinghua-Peking Center for Life Sciences, School of Life Sciences, Tsinghua University, Beijing 100084, China
| | - Shunji Jia
- From the Laboratory of Molecular Developmental Biology, State Key Laboratory of Membrane Biology, Tsinghua-Peking Center for Life Sciences, School of Life Sciences, Tsinghua University, Beijing 100084, China
| | - Anming Meng
- From the Laboratory of Molecular Developmental Biology, State Key Laboratory of Membrane Biology, Tsinghua-Peking Center for Life Sciences, School of Life Sciences, Tsinghua University, Beijing 100084, China
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Martinez H, García IA, Sampieri L, Alvarez C. Spatial-Temporal Study of Rab1b Dynamics and Function at the ER-Golgi Interface. PLoS One 2016; 11:e0160838. [PMID: 27500526 PMCID: PMC4976911 DOI: 10.1371/journal.pone.0160838] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2015] [Accepted: 07/26/2016] [Indexed: 12/27/2022] Open
Abstract
The GTPase Rab1b is involved in ER to Golgi transport, with multiple Rab1b effectors (located at ERES, VTCs and the Golgi complex) being required for its function. In this study, we performed live-cell dual-expression studies to analyze the dynamics of Rab1b and some effectors located at the ERES-Golgi interface. Rab1b occupied widely distributed mobile punctate and tubular structures, displaying a transient overlaps with its effectors and showing that these overlaps occurred at the same time in spatially distinct steps of ER to Golgi transport. In addition, we assessed Rab1b dynamics during cargo sorting by analyzing the concentration at ERES of a Golgi protein (SialT2-CFP) during Brefeldin A washout (BFA WO). Rab1b was associated to most of the ERES structures, but at different times during BFA WO, and recurrently SialT2-CFP was sorted in the ERES-Rab1b positive structures. Furthermore, we reveal for first time that Rab1b localization time at ERES depended on GBF1, a Rab1b effector that acts as the guanine nucleotide exchange factor of Arf1, and that Rab1b membrane association/dissociation dynamics at ERES was dependent on the GBF1 membrane association and activity, which strongly suggests that GBF1 activity modulates Rab1b membrane cycling dynamic.
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Affiliation(s)
- Hernán Martinez
- Centro de Investigaciones en Bioquímica Clínica e Inmunología (CIBICI-CONICET), Departamento de Bioquímica Clínica, Facultad de Ciencias Químicas, Universidad Nacional de Córdoba, Córdoba 5000, Argentina
| | - Iris A. García
- Centro de Investigaciones en Bioquímica Clínica e Inmunología (CIBICI-CONICET), Departamento de Bioquímica Clínica, Facultad de Ciencias Químicas, Universidad Nacional de Córdoba, Córdoba 5000, Argentina
| | - Luciana Sampieri
- Centro de Investigaciones en Bioquímica Clínica e Inmunología (CIBICI-CONICET), Departamento de Bioquímica Clínica, Facultad de Ciencias Químicas, Universidad Nacional de Córdoba, Córdoba 5000, Argentina
| | - Cecilia Alvarez
- Centro de Investigaciones en Bioquímica Clínica e Inmunología (CIBICI-CONICET), Departamento de Bioquímica Clínica, Facultad de Ciencias Químicas, Universidad Nacional de Córdoba, Córdoba 5000, Argentina
- * E-mail:
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Saraste J, Marie M. Intermediate Compartment: A Sorting Station between the Endoplasmic Reticulum and the Golgi Apparatus. ENCYCLOPEDIA OF CELL BIOLOGY 2016. [PMCID: PMC7150006 DOI: 10.1016/b978-0-12-394447-4.20013-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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Bhatt JM, Viktorova EG, Busby T, Wyrozumska P, Newman LE, Lin H, Lee E, Wright J, Belov GA, Kahn RA, Sztul E. Oligomerization of the Sec7 domain Arf guanine nucleotide exchange factor GBF1 is dispensable for Golgi localization and function but regulates degradation. Am J Physiol Cell Physiol 2015; 310:C456-69. [PMID: 26718629 DOI: 10.1152/ajpcell.00185.2015] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2015] [Accepted: 12/14/2015] [Indexed: 12/15/2022]
Abstract
Members of the large Sec7 domain-containing Arf guanine nucleotide exchange factor (GEF) family have been shown to dimerize through their NH2-terminal dimerization and cyclophilin binding (DCB) and homology upstream of Sec7 (HUS) domains. However, the importance of dimerization in GEF localization and function has not been assessed. We generated a GBF1 mutant (91/130) in which two residues required for oligomerization (K91 and E130 within the DCB domain) were replaced with A and assessed the effects of these mutations on GBF1 localization and cellular functions. We show that 91/130 is compromised in oligomerization but that it targets to the Golgi in a manner indistinguishable from wild-type GBF1 and that it rapidly exchanges between the cytosolic and membrane-bound pools. The 91/130 mutant appears active as it integrates within the functional network at the Golgi, supports Arf activation and COPI recruitment, and sustains Golgi homeostasis and cargo secretion when provided as a sole copy of functional GBF1 in cells. In addition, like wild-type GBF1, the 91/130 mutant supports poliovirus RNA replication, a process requiring GBF1 but believed to be independent of GBF1 catalytic activity. However, oligomerization appears to stabilize GBF1 in cells, and the 91/130 mutant is degraded faster than the wild-type GBF1. Our data support a model in which oligomerization is not a key regulator of GBF1 activity but impacts its function by regulating the cellular levels of GBF1.
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Affiliation(s)
- Jay M Bhatt
- Department of Cell, Developmental and Integrative Biology, University of Alabama at Birmingham, Birmingham, Alabama
| | - Ekaterina G Viktorova
- Department of Veterinary Medicine, Virginia-Maryland Regional College of Veterinary Medicine, University of Maryland, College Park, Maryland; and
| | - Theodore Busby
- Department of Cell, Developmental and Integrative Biology, University of Alabama at Birmingham, Birmingham, Alabama
| | - Paulina Wyrozumska
- Department of Cell, Developmental and Integrative Biology, University of Alabama at Birmingham, Birmingham, Alabama
| | - Laura E Newman
- Department of Biochemistry, Emory University School of Medicine, Atlanta, Georgia
| | - Helen Lin
- Department of Cell, Developmental and Integrative Biology, University of Alabama at Birmingham, Birmingham, Alabama
| | - Eunjoo Lee
- Department of Cell, Developmental and Integrative Biology, University of Alabama at Birmingham, Birmingham, Alabama
| | - John Wright
- Department of Cell, Developmental and Integrative Biology, University of Alabama at Birmingham, Birmingham, Alabama
| | - George A Belov
- Department of Veterinary Medicine, Virginia-Maryland Regional College of Veterinary Medicine, University of Maryland, College Park, Maryland; and
| | - Richard A Kahn
- Department of Biochemistry, Emory University School of Medicine, Atlanta, Georgia
| | - Elizabeth Sztul
- Department of Cell, Developmental and Integrative Biology, University of Alabama at Birmingham, Birmingham, Alabama;
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Regulators and Effectors of Arf GTPases in Neutrophils. J Immunol Res 2015; 2015:235170. [PMID: 26609537 PMCID: PMC4644846 DOI: 10.1155/2015/235170] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2015] [Accepted: 09/30/2015] [Indexed: 12/22/2022] Open
Abstract
Polymorphonuclear neutrophils (PMNs) are key innate immune cells that represent the first line of defence against infection. They are the first leukocytes to migrate from the blood to injured or infected sites. This process involves molecular mechanisms that coordinate cell polarization, delivery of receptors, and activation of integrins at the leading edge of migrating PMNs. These phagocytes actively engulf microorganisms or form neutrophil extracellular traps (NETs) to trap and kill pathogens with bactericidal compounds. Association of the NADPH oxidase complex at the phagosomal membrane for production of reactive oxygen species (ROS) and delivery of proteolytic enzymes into the phagosome initiate pathogen killing and removal. G protein-dependent signalling pathways tightly control PMN functions. In this review, we will focus on the small monomeric GTPases of the Arf family and their guanine exchange factors (GEFs) and GTPase activating proteins (GAPs) as components of signalling cascades regulating PMN responses. GEFs and GAPs are multidomain proteins that control cellular events in time and space through interaction with other proteins and lipids inside the cells. The number of Arf GAPs identified in PMNs is expanding, and dissecting their functions will provide important insights into the role of these proteins in PMN physiology.
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Microsomal Triglyceride Transfer Protein (MTP) Associates with Cytosolic Lipid Droplets in 3T3-L1 Adipocytes. PLoS One 2015; 10:e0135598. [PMID: 26267806 PMCID: PMC4534446 DOI: 10.1371/journal.pone.0135598] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2014] [Accepted: 07/16/2015] [Indexed: 12/18/2022] Open
Abstract
Lipid droplets are intracellular energy storage organelles composed of a hydrophobic core of neutral lipid, surrounded by a monolayer of phospholipid and a diverse array of proteins. The function of the vast majority of these proteins with regard to the formation and/or turnover of lipid droplets is unknown. Our laboratory was the first to report that microsomal triglyceride transfer protein (MTP), a lipid transfer protein essential for the assembly of triglyceride-rich lipoproteins, was expressed in adipose tissue of humans and mice. In addition, our studies suggested that MTP was associated with lipid droplets in both brown and white fat. Our observations led us to hypothesize that MTP plays a key role in lipid droplet formation and/or turnover. The objective of these studies was to gain insight into the function of MTP in adipocytes. Using molecular, biochemical, and morphologic approaches we have shown: 1) MTP protein levels increase nearly five-fold as 3T3-L1 cells differentiate into adipocytes. 2) As 3T3-L1 cells undergo differentiation, MTP moves from the juxtanuclear region of the cell to the surface of lipid droplets. MTP and perilipin 2, a major lipid droplet surface protein, are found on the same droplets; however, MTP does not co-localize with perilipin 2. 3) Inhibition of MTP activity has no effect on the movement of triglyceride out of the cell either as a lipid complex or via lipolysis. 4) MTP is found associated with lipid droplets within hepatocytes from human fatty livers, suggesting that association of MTP with lipid droplets is not restricted to adipocytes. In summary, our data demonstrate that MTP is a lipid droplet-associated protein. Its location on the surface of the droplet in adipocytes and hepatocytes, coupled with its known function as a lipid transfer protein and its increased expression during adipocyte differentiation suggest a role in lipid droplet biology.
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Szul T, Burgess J, Jeon M, Zinn K, Marques G, Brill JA, Sztul E. The Garz Sec7 domain guanine nucleotide exchange factor for Arf regulates salivary gland development in Drosophila. CELLULAR LOGISTICS 2014; 1:69-76. [PMID: 21686256 DOI: 10.4161/cl.1.2.15512] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/08/2011] [Revised: 03/11/2011] [Accepted: 03/17/2011] [Indexed: 12/22/2022]
Abstract
Surface delivery of proteins involved in cell-cell and cell-matrix interactions in cultured mammalian cells requires the GBF1 guanine nucleotide exchange factor. However, the role of GBF1 in delivery of adhesion proteins during organogenesis in intact animals has not been characterized. Here, we report the function of the fly GBF1 homolog, Gartenzwerg (Garz) in the development of the salivary gland in Drosophila melanogaster. We used the GAL4/UAS system to selectively deplete Garz from salivary gland cells. We show that depletion of Garz disrupts the secretory pathway as evidenced by the collapse of Golgi-localized Lava lamp (Lva) and the TGN-localized γ subunit of the clathrin-adaptor protein complex (AP-1). Additionally, Garz depletion inhibits trafficking of cell-cell adhesion proteins cadherin (DE-cad) and Flamingo to the cell surface. Disregulation of trafficking correlates with mistargeting of the tumor suppressor protein Discs large involved in epithelial polarity determination. Garz-depleted salivary cells are smaller and lack well-defined plasma membrane domains. Garz depletion also inhibits normal elongation and positioning of epithelial cells, resulting in a disorganized salivary gland that lacks a well defined luminal duct. Our findings suggest that Garz is essential for establishment of epithelial structures and demonstrate an absolute requirement for Garz during Drosophila development.
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Affiliation(s)
- Tomasz Szul
- Department of Cell Biology; University of Alabama at Birmingham; Birmingham, AL USA
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Abstract
In vitro reconstitution is prerequisite to investigate complex cellular functions at the molecular level. Reconstitution systems range from combining complete cellular cytosol with organelle-enriched membrane fractions to liposomal systems where all components are chemically defined and can be chosen at will. Here, we describe the in vitro reconstitution of COPI-coated vesicles from semi-intact cells. Efficient vesicle formation is achieved by simple incubation of permeabilized cells with the minimal set of coat proteins Arf1 and coatomer, and guanosine trinucleotides. GTP hydrolysis or any mechanical manipulations are not required for efficient COPI vesicle release.
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Wang J, Du J, Jin Q. Class I ADP-ribosylation factors are involved in enterovirus 71 replication. PLoS One 2014; 9:e99768. [PMID: 24911624 PMCID: PMC4049829 DOI: 10.1371/journal.pone.0099768] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2014] [Accepted: 05/16/2014] [Indexed: 12/16/2022] Open
Abstract
Enterovirus 71 is one of the major causative agents of hand, foot, and mouth disease in infants and children. Replication of enterovirus 71 depends on host cellular factors. The viral replication complex is formed in novel, cytoplasmic, vesicular compartments. It has not been elucidated which cellular pathways are hijacked by the virus to create these vesicles. Here, we investigated whether proteins associated with the cellular secretory pathway were involved in enterovirus 71 replication. We used a loss-of-function assay, based on small interfering RNA. We showed that enterovirus 71 RNA replication was dependent on the activity of Class I ADP-ribosylation factors. Simultaneous depletion of ADP-ribosylation factors 1 and 3, but not three others, inhibited viral replication in cells. We also demonstrated with various techniques that the brefeldin-A-sensitive guanidine nucleotide exchange factor, GBF1, was critically important for enterovirus 71 replication. Our results suggested that enterovirus 71 replication depended on GBF1-mediated activation of Class I ADP-ribosylation factors. These results revealed a connection between enterovirus 71 replication and the cellular secretory pathway; this pathway may represent a novel target for antiviral therapies.
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Affiliation(s)
- Jianmin Wang
- MOH Key Laboratory of Systems Biology of Pathogens, Institute of Pathogen Biology, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, People's Republic of China
| | - Jiang Du
- MOH Key Laboratory of Systems Biology of Pathogens, Institute of Pathogen Biology, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, People's Republic of China
| | - Qi Jin
- MOH Key Laboratory of Systems Biology of Pathogens, Institute of Pathogen Biology, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, People's Republic of China
- * E-mail:
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Regulating the large Sec7 ARF guanine nucleotide exchange factors: the when, where and how of activation. Cell Mol Life Sci 2014; 71:3419-38. [PMID: 24728583 DOI: 10.1007/s00018-014-1602-7] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2013] [Revised: 02/27/2014] [Accepted: 03/03/2014] [Indexed: 10/25/2022]
Abstract
Eukaryotic cells require selective sorting and transport of cargo between intracellular compartments. This is accomplished at least in part by vesicles that bud from a donor compartment, sequestering a subset of resident protein "cargos" destined for transport to an acceptor compartment. A key step in vesicle formation and targeting is the recruitment of specific proteins that form a coat on the outside of the vesicle in a process requiring the activation of regulatory GTPases of the ARF family. Like all such GTPases, ARFs cycle between inactive, GDP-bound, and membrane-associated active, GTP-bound, conformations. And like most regulatory GTPases the activating step is slow and thought to be rate limiting in cells, requiring the use of ARF guanine nucleotide exchange factor (GEFs). ARF GEFs are characterized by the presence of a conserved, catalytic Sec7 domain, though they also contain motifs or additional domains that confer specificity to localization and regulation of activity. These domains have been used to define and classify five different sub-families of ARF GEFs. One of these, the BIG/GBF1 family, includes three proteins that are each key regulators of the secretory pathway. GEF activity initiates the coating of nascent vesicles via the localized generation of activated ARFs and thus these GEFs are the upstream regulators that define the site and timing of vesicle production. Paradoxically, while we have detailed molecular knowledge of how GEFs activate ARFs, we know very little about how GEFs are recruited and/or activated at the right time and place to initiate transport. This review summarizes the current knowledge of GEF regulation and explores the still uncertain mechanisms that position GEFs at "budding ready" membrane sites to generate highly localized activated ARFs.
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Wyrozumska P, Ashley JW, Ramanadham S, Liu Q, Garvey WT, Sztul E. Novel effects of Brefeldin A (BFA) in signaling through the insulin receptor (IR) pathway and regulating FoxO1-mediated transcription. CELLULAR LOGISTICS 2014; 4:e27732. [PMID: 24843827 PMCID: PMC4022606 DOI: 10.4161/cl.27732] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/14/2013] [Revised: 01/02/2014] [Accepted: 01/03/2014] [Indexed: 12/19/2022]
Abstract
Brefeldin A (BFA) is a fungal metabolite best known for its ability to inhibit activation of ADP-ribosylation factor (Arf) and thereby inhibit secretory traffic. BFA also appears to regulate the trafficking of the GLUT4 glucose transporter by inducing its relocation from intracellular stores to the cell surface. Such redistribution of GLUT4 is normally regulated by insulin-mediated signaling. Hence, we tested whether BFA may intersect with the insulin pathway. We report that BFA causes the activation of the insulin receptor (IR), IRS-1, Akt-2, and AS160 components of the insulin pathway. The response is mediated through phosphoinositol-3-kinase (PI3K) and Akt kinase since the PI3K inhibitor wortmannin and the Akt inhibitors MK2206 and perifosine inhibit the BFA effect. BFA-mediated activation of the insulin pathway results in Akt-mediated phosphorylation of the insulin-responsive transcription factor FoxO1. This leads to nuclear exclusion of FoxO1 and a decrease in transcription of the insulin-responsive gene SIRT-1. Our findings suggest novel effects for BFA in signaling and transcription, and imply that BFA has multiple intracellular targets and can be used to regulate diverse cellular responses that include vesicular trafficking, signaling and transcription.
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Affiliation(s)
- Paulina Wyrozumska
- Department of Cell, Developmental and Integrative Biology; University of Alabama at Birmingham; Birmingham, AL USA
| | - Jason W Ashley
- Department of Cell, Developmental and Integrative Biology; University of Alabama at Birmingham; Birmingham, AL USA
| | - Sasanka Ramanadham
- Department of Cell, Developmental and Integrative Biology; University of Alabama at Birmingham; Birmingham, AL USA
| | - Qinglan Liu
- Department of Nutrition Sciences University of Alabama at Birmingham; Birmingham, AL USA
| | - W Timothy Garvey
- Department of Nutrition Sciences University of Alabama at Birmingham; Birmingham, AL USA
| | - Elizabeth Sztul
- Department of Cell, Developmental and Integrative Biology; University of Alabama at Birmingham; Birmingham, AL USA
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Naydenov NG, Feygin A, Wang L, Ivanov AI. N-ethylmaleimide-sensitive factor attachment protein α (αSNAP) regulates matrix adhesion and integrin processing in human epithelial cells. J Biol Chem 2013; 289:2424-39. [PMID: 24311785 DOI: 10.1074/jbc.m113.498691] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Integrin-based adhesion to the extracellular matrix (ECM) plays critical roles in controlling differentiation, survival, and motility of epithelial cells. Cells attach to the ECM via dynamic structures called focal adhesions (FA). FA undergo constant remodeling mediated by vesicle trafficking and fusion. A soluble N-ethylmaleimide-sensitive factor (NSF) attachment protein α (αSNAP) is an essential mediator of membrane fusion; however, its roles in regulating ECM adhesion and cell motility remain unexplored. In this study, we found that siRNA-mediated knockdown of αSNAP induced detachment of intestinal epithelial cells, whereas overexpression of αSNAP increased ECM adhesion and inhibited cell invasion. Loss of αSNAP impaired Golgi-dependent glycosylation and trafficking of β1 integrin and decreased phosphorylation of focal adhesion kinase (FAK) and paxillin resulting in FA disassembly. These effects of αSNAP depletion on ECM adhesion were independent of apoptosis and NSF. In agreement with our previous reports that Golgi fragmentation mediates cellular effects of αSNAP knockdown, we found that either pharmacologic or genetic disruption of the Golgi recapitulated all the effects of αSNAP depletion on ECM adhesion. Furthermore, our data implicates β1 integrin, FAK, and paxillin in mediating the observed pro-adhesive effects of αSNAP. These results reveal novel roles for αSNAP in regulating ECM adhesion and motility of epithelial cells.
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Téoulé F, Brisac C, Pelletier I, Vidalain PO, Jégouic S, Mirabelli C, Bessaud M, Combelas N, Autret A, Tangy F, Delpeyroux F, Blondel B. The Golgi protein ACBD3, an interactor for poliovirus protein 3A, modulates poliovirus replication. J Virol 2013; 87:11031-46. [PMID: 23926333 PMCID: PMC3807280 DOI: 10.1128/jvi.00304-13] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2013] [Accepted: 07/19/2013] [Indexed: 01/11/2023] Open
Abstract
We have shown that the circulating vaccine-derived polioviruses responsible for poliomyelitis outbreaks in Madagascar have recombinant genomes composed of sequences encoding capsid proteins derived from poliovaccine Sabin, mostly type 2 (PVS2), and sequences encoding nonstructural proteins derived from other human enteroviruses. Interestingly, almost all of these recombinant genomes encode a nonstructural 3A protein related to that of field coxsackievirus A17 (CV-A17) strains. Here, we investigated the repercussions of this exchange, by assessing the role of the 3A proteins of PVS2 and CV-A17 and their putative cellular partners in viral replication. We found that the Golgi protein acyl-coenzyme A binding domain-containing 3 (ACBD3), recently identified as an interactor for the 3A proteins of several picornaviruses, interacts with the 3A proteins of PVS2 and CV-A17 at viral RNA replication sites, in human neuroblastoma cells infected with either PVS2 or a PVS2 recombinant encoding a 3A protein from CV-A17 [PVS2-3A(CV-A17)]. The small interfering RNA-mediated downregulation of ACBD3 significantly increased the growth of both viruses, suggesting that ACBD3 slowed viral replication. This was confirmed with replicons. Furthermore, PVS2-3A(CV-A17) was more resistant to the replication-inhibiting effect of ACBD3 than the PVS2 strain, and the amino acid in position 12 of 3A was involved in modulating the sensitivity of viral replication to ACBD3. Overall, our results indicate that exchanges of nonstructural proteins can modify the relationships between enterovirus recombinants and cellular interactors and may thus be one of the factors favoring their emergence.
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Affiliation(s)
- François Téoulé
- Institut Pasteur, Unité de Biologie des Virus Entériques, Paris, France
- INSERM U994, Paris, France
- Université Versailles Saint-Quentin, Versailles, France
| | - Cynthia Brisac
- Institut Pasteur, Unité de Biologie des Virus Entériques, Paris, France
- INSERM U994, Paris, France
- Université Versailles Saint-Quentin, Versailles, France
| | - Isabelle Pelletier
- Institut Pasteur, Unité de Biologie des Virus Entériques, Paris, France
- INSERM U994, Paris, France
| | - Pierre-Olivier Vidalain
- Institut Pasteur, Unité de Génomique Virale et Vaccination, Paris, France
- CNRS URA 3015, Paris, France
| | - Sophie Jégouic
- Institut Pasteur, Unité de Biologie des Virus Entériques, Paris, France
- INSERM U994, Paris, France
| | - Carmen Mirabelli
- Institut Pasteur, Unité de Biologie des Virus Entériques, Paris, France
| | - Maël Bessaud
- Institut Pasteur, Unité de Biologie des Virus Entériques, Paris, France
- INSERM U994, Paris, France
| | - Nicolas Combelas
- Institut Pasteur, Unité de Biologie des Virus Entériques, Paris, France
- INSERM U994, Paris, France
| | - Arnaud Autret
- Institut Pasteur, Unité de Biologie des Virus Entériques, Paris, France
- INSERM U994, Paris, France
| | - Frédéric Tangy
- Institut Pasteur, Unité de Génomique Virale et Vaccination, Paris, France
- CNRS URA 3015, Paris, France
| | - Francis Delpeyroux
- Institut Pasteur, Unité de Biologie des Virus Entériques, Paris, France
- INSERM U994, Paris, France
| | - Bruno Blondel
- Institut Pasteur, Unité de Biologie des Virus Entériques, Paris, France
- INSERM U994, Paris, France
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48
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Midgley R, Moffat K, Berryman S, Hawes P, Simpson J, Fullen D, Stephens DJ, Burman A, Jackson T. A role for endoplasmic reticulum exit sites in foot-and-mouth disease virus infection. J Gen Virol 2013; 94:2636-2646. [PMID: 23963534 PMCID: PMC3836498 DOI: 10.1099/vir.0.055442-0] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Picornaviruses replicate their genomes in association with cellular membranes. While enteroviruses are believed to utilize membranes of the early secretory pathway, the origin of the membranes used by foot-and-mouth disease virus (FMDV) for replication are unknown. Secretory-vesicle traffic through the early secretory pathway is mediated by the sequential acquisition of two distinct membrane coat complexes, COPII and COPI, and requires the coordinated actions of Sar1, Arf1 and Rab proteins. Sar1 is essential for generating COPII vesicles at endoplasmic reticulum (ER) exit sites (ERESs), while Arf1 and Rab1 are required for subsequent vesicle transport by COPI vesicles. In the present study, we have provided evidence that FMDV requires pre-Golgi membranes of the early secretory pathway for infection. Small interfering RNA depletion of Sar1 or expression of a dominant-negative (DN) mutant of Sar1a inhibited FMDV infection. In contrast, a dominant-active mutant of Sar1a, which allowed COPII vesicle formation but inhibited the secretory pathway by stabilizing COPII coats, caused major disruption to the ER–Golgi intermediate compartment (ERGIC) but did not inhibit infection. Treatment of cells with brefeldin A, or expression of DN mutants of Arf1 and Rab1a, disrupted the Golgi and enhanced FMDV infection. These results show that reagents that block the early secretory pathway at ERESs have an inhibitory effect on FMDV infection, while reagents that block the early secretory pathway immediately after ER exit but before the ERGIC and Golgi make infection more favourable. Together, these observations argue for a role for Sar1 in FMDV infection and that initial virus replication takes place on membranes that are formed at ERESs.
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Affiliation(s)
| | - Katy Moffat
- The Pirbright Institute, Pirbright, Surrey GU24 0NF, UK
| | | | | | | | - Daniel Fullen
- The Pirbright Institute, Pirbright, Surrey GU24 0NF, UK
| | - David J Stephens
- Cell Biology Laboratories, School of Biochemistry, Medical Sciences Building, University of Bristol, University Walk, Bristol BS8 1TD, UK
| | - Alison Burman
- The Pirbright Institute, Pirbright, Surrey GU24 0NF, UK
| | - Terry Jackson
- The Pirbright Institute, Pirbright, Surrey GU24 0NF, UK
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Nakai W, Kondo Y, Saitoh A, Naito T, Nakayama K, Shin HW. ARF1 and ARF4 regulate recycling endosomal morphology and retrograde transport from endosomes to the Golgi apparatus. Mol Biol Cell 2013; 24:2570-81. [PMID: 23783033 PMCID: PMC3744953 DOI: 10.1091/mbc.e13-04-0197] [Citation(s) in RCA: 61] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
Abstract
The ARF1+ARF4 and ARF1+ARF3 pairs are both required for integrity of recycling endosomes but are involved in distinct transport pathways: the former pair regulates retrograde transport from endosomes to the TGN, whereas the latter is required for the transferrin recycling pathway from endosomes to the plasma membrane. Small GTPases of the ADP-ribosylation factor (ARF) family, except for ARF6, mainly localize to the Golgi apparatus, where they trigger formation of coated carrier vesicles. We recently showed that class I ARFs (ARF1 and ARF3) localize to recycling endosomes, as well as to the Golgi, and are redundantly required for recycling of endocytosed transferrin. On the other hand, the roles of class II ARFs (ARF4 and ARF5) are not yet fully understood, and the complementary or overlapping functions of class I and class II ARFs have been poorly characterized. In this study, we find that simultaneous depletion of ARF1 and ARF4 induces extensive tubulation of recycling endosomes. Moreover, the depletion of ARF1 and ARF4 inhibits retrograde transport of TGN38 and mannose-6-phosphate receptor from early/recycling endosomes to the trans-Golgi network (TGN) but does not affect the endocytic/recycling pathway of transferrin receptor or inhibit retrograde transport of CD4-furin from late endosomes to the TGN. These observations indicate that the ARF1+ARF4 and ARF1+ARF3 pairs are both required for integrity of recycling endosomes but are involved in distinct transport pathways: the former pair regulates retrograde transport from endosomes to the TGN, whereas the latter is required for the transferrin recycling pathway from endosomes to the plasma membrane.
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Affiliation(s)
- Waka Nakai
- Graduate School of Pharmaceutical Sciences, Kyoto University, Sakyo-ku, Kyoto 606-8501, Japan
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50
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Adolf F, Herrmann A, Hellwig A, Beck R, Brügger B, Wieland FT. Scission of COPI and COPII vesicles is independent of GTP hydrolysis. Traffic 2013; 14:922-32. [PMID: 23691917 DOI: 10.1111/tra.12084] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2012] [Revised: 05/15/2013] [Accepted: 05/20/2013] [Indexed: 12/29/2022]
Abstract
Intracellular transport and maintenance of the endomembrane system in eukaryotes depends on formation and fusion of vesicular carriers. A seeming discrepancy exists in the literature about the basic mechanism in the scission of transport vesicles that depend on GTP-binding proteins. Some reports describe that the scission of COP-coated vesicles is dependent on GTP hydrolysis, whereas others found that GTP hydrolysis is not required. In order to investigate this pivotal mechanism in vesicle formation, we analyzed formation of COPI- and COPII-coated vesicles utilizing semi-intact cells. The small GTPases Sar1 and Arf1 together with their corresponding coat proteins, the Sec23/24 and Sec13/31 complexes for COPII and coatomer for COPI vesicles were required and sufficient to drive vesicle formation. Both types of vesicles were efficiently generated when GTP hydrolysis was blocked either by utilizing the poorly hydrolyzable GTP analogs GTPγS and GMP-PNP, or with constitutively active mutants of the small GTPases. Thus, GTP hydrolysis is not required for the formation and release of COP vesicles.
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Affiliation(s)
- Frank Adolf
- Heidelberg University Biochemistry Center, University of Heidelberg, Im Neuenheimer Feld 328, D-69120, Heidelberg, Germany
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