1
|
Quirion L, Robert A, Boulais J, Huang S, Bernal Astrain G, Strakhova R, Jo CH, Kherdjemil Y, Faubert D, Thibault MP, Kmita M, Baskin JM, Gingras AC, Smith MJ, Côté JF. Mapping the global interactome of the ARF family reveals spatial organization in cellular signaling pathways. J Cell Sci 2024; 137:jcs262140. [PMID: 38606629 PMCID: PMC11166204 DOI: 10.1242/jcs.262140] [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: 03/23/2024] [Accepted: 04/08/2024] [Indexed: 04/13/2024] Open
Abstract
The ADP-ribosylation factors (ARFs) and ARF-like (ARL) GTPases serve as essential molecular switches governing a wide array of cellular processes. In this study, we used proximity-dependent biotin identification (BioID) to comprehensively map the interactome of 28 out of 29 ARF and ARL proteins in two cellular models. Through this approach, we identified ∼3000 high-confidence proximal interactors, enabling us to assign subcellular localizations to the family members. Notably, we uncovered previously undefined localizations for ARL4D and ARL10. Clustering analyses further exposed the distinctiveness of the interactors identified with these two GTPases. We also reveal that the expression of the understudied member ARL14 is confined to the stomach and intestines. We identified phospholipase D1 (PLD1) and the ESCPE-1 complex, more precisely, SNX1, as proximity interactors. Functional assays demonstrated that ARL14 can activate PLD1 in cellulo and is involved in cargo trafficking via the ESCPE-1 complex. Overall, the BioID data generated in this study provide a valuable resource for dissecting the complexities of ARF and ARL spatial organization and signaling.
Collapse
Affiliation(s)
- Laura Quirion
- Montreal Clinical Research Institute (IRCM), Montréal, QC H2W 1R7, Canada
- Molecular Biology Programs, Université de Montréal, Montréal, QC H3T 1J4, Canada
| | - Amélie Robert
- Montreal Clinical Research Institute (IRCM), Montréal, QC H2W 1R7, Canada
| | - Jonathan Boulais
- Montreal Clinical Research Institute (IRCM), Montréal, QC H2W 1R7, Canada
| | - Shiying Huang
- Department of Chemistry and Chemical Biology and Weill Institute for Cell and Molecular Biology, Cornell University, Ithaca, NY 14853, USA
| | - Gabriela Bernal Astrain
- Molecular Biology Programs, Université de Montréal, Montréal, QC H3T 1J4, Canada
- Institute for Research in Immunology and Cancer, Université de Montréal, Montréal, QC H3T 1J4, Canada
| | - Regina Strakhova
- Molecular Biology Programs, Université de Montréal, Montréal, QC H3T 1J4, Canada
- Institute for Research in Immunology and Cancer, Université de Montréal, Montréal, QC H3T 1J4, Canada
| | - Chang Hwa Jo
- Institute for Research in Immunology and Cancer, Université de Montréal, Montréal, QC H3T 1J4, Canada
| | - Yacine Kherdjemil
- Montreal Clinical Research Institute (IRCM), Montréal, QC H2W 1R7, Canada
| | - Denis Faubert
- Montreal Clinical Research Institute (IRCM), Montréal, QC H2W 1R7, Canada
| | | | - Marie Kmita
- Montreal Clinical Research Institute (IRCM), Montréal, QC H2W 1R7, Canada
- Molecular Biology Programs, Université de Montréal, Montréal, QC H3T 1J4, Canada
- Department of Medicine, Université de Montréal, Montréal, QC H3C 3J7, Canada
- Department of Experimental Medicine, McGill University, Montréal, QC H3G 2M1, Canada
| | - Jeremy M. Baskin
- Department of Chemistry and Chemical Biology and Weill Institute for Cell and Molecular Biology, Cornell University, Ithaca, NY 14853, USA
| | - Anne-Claude Gingras
- Lunenfeld-Tanenbaum Research Institute, Sinai Health System, Toronto, ON M5G 1X5, Canada
- Department of Molecular Genetics, University of Toronto, Toronto, ON M5S 1A8, Canada
| | - Matthew J. Smith
- Institute for Research in Immunology and Cancer, Université de Montréal, Montréal, QC H3T 1J4, Canada
| | - Jean-François Côté
- Montreal Clinical Research Institute (IRCM), Montréal, QC H2W 1R7, Canada
- Molecular Biology Programs, Université de Montréal, Montréal, QC H3T 1J4, Canada
- Department of Medicine, Université de Montréal, Montréal, QC H3C 3J7, Canada
- Department of Anatomy and Cell Biology, McGill University, Montréal, QC H3A 0C7, Canada
| |
Collapse
|
2
|
Quirion L, Robert A, Boulais J, Huang S, Bernal Astrain G, Strakhova R, Jo CH, Kherdjemil Y, Thibault MP, Faubert D, Kmita M, Baskin JM, Gingras AC, Smith MJ, Cote JF. Mapping the global interactome of the ARF family reveals spatial organization in cellular signaling pathways. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2023.03.01.530598. [PMID: 36909472 PMCID: PMC10002736 DOI: 10.1101/2023.03.01.530598] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/06/2023]
Abstract
The ADP-ribosylation factors (ARFs) and ARF-like (ARLs) GTPases serve as essential molecular switches governing a wide array of cellular processes. In this study, we utilized proximity-dependent biotin identification (BioID) to comprehensively map the interactome of 28 out of 29 ARF and ARL proteins in two cellular models. Through this approach, we identified ~3000 high-confidence proximal interactors, enabling us to assign subcellular localizations to the family members. Notably, we uncovered previously undefined localizations for ARL4D and ARL10. Clustering analyses further exposed the distinctiveness of the interactors identified with these two GTPases. We also reveal that the expression of the understudied member ARL14 is confined to the stomach and intestines. We identified phospholipase D1 (PLD1) and the ESCPE-1 complex, more precisely SNX1, as proximity interactors. Functional assays demonstrated that ARL14 can activate PLD1 in cellulo and is involved in cargo trafficking via the ESCPE-1 complex. Overall, the BioID data generated in this study provide a valuable resource for dissecting the complexities of ARF and ARL spatial organization and signaling.
Collapse
|
3
|
Lin SJ, Lin MC, Liu TJ, Tsai YT, Tsai MT, Lee FJS. Endosomal Arl4A attenuates EGFR degradation by binding to the ESCRT-II component VPS36. Nat Commun 2023; 14:7859. [PMID: 38030597 PMCID: PMC10687025 DOI: 10.1038/s41467-023-42979-9] [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: 10/20/2022] [Accepted: 10/25/2023] [Indexed: 12/01/2023] Open
Abstract
Ligand-induced epidermal growth factor receptor (EGFR) endocytosis followed by endosomal EGFR signaling and lysosomal degradation plays important roles in controlling multiple biological processes. ADP-ribosylation factor (Arf)-like protein 4 A (Arl4A) functions at the plasma membrane to mediate cytoskeletal remodeling and cell migration, whereas its localization at endosomal compartments remains functionally unknown. Here, we report that Arl4A attenuates EGFR degradation by binding to the endosomal sorting complex required for transport (ESCRT)-II component VPS36. Arl4A plays a role in prolonging the duration of EGFR ubiquitinylation and deterring endocytosed EGFR transport from endosomes to lysosomes under EGF stimulation. Mechanistically, the Arl4A-VPS36 direct interaction stabilizes VPS36 and ESCRT-III association, affecting subsequent recruitment of deubiquitinating-enzyme USP8 by CHMP2A. Impaired Arl4A-VPS36 interaction enhances EGFR degradation and clearance of EGFR ubiquitinylation. Together, we discover that Arl4A negatively regulates EGFR degradation by binding to VPS36 and attenuating ESCRT-mediated late endosomal EGFR sorting.
Collapse
Affiliation(s)
- Shin-Jin Lin
- Institute of Molecular Medicine, College of Medicine, National Taiwan University, 10002, Taipei, Taiwan
- Department of Medical Research, National Taiwan University Hospital, 10002, Taipei, Taiwan
| | - Ming-Chieh Lin
- Institute of Molecular Medicine, College of Medicine, National Taiwan University, 10002, Taipei, Taiwan
- Department of Medical Research, National Taiwan University Hospital, 10002, Taipei, Taiwan
| | - Tsai-Jung Liu
- Institute of Molecular Medicine, College of Medicine, National Taiwan University, 10002, Taipei, Taiwan
- Department of Medical Research, National Taiwan University Hospital, 10002, Taipei, Taiwan
| | - Yueh-Tso Tsai
- Institute of Molecular Medicine, College of Medicine, National Taiwan University, 10002, Taipei, Taiwan
| | - Ming-Ting Tsai
- Institute of Molecular Medicine, College of Medicine, National Taiwan University, 10002, Taipei, Taiwan
| | - Fang-Jen S Lee
- Institute of Molecular Medicine, College of Medicine, National Taiwan University, 10002, Taipei, Taiwan.
- Department of Medical Research, National Taiwan University Hospital, 10002, Taipei, Taiwan.
- Center of Precision Medicine, College of Medicine, National Taiwan University, Taipei, 10002, Taiwan.
| |
Collapse
|
4
|
Manzer KM, Fromme JC. The Arf-GAP Age2 localizes to the late-Golgi via a conserved amphipathic helix. Mol Biol Cell 2023; 34:ar119. [PMID: 37672345 PMCID: PMC10846627 DOI: 10.1091/mbc.e23-07-0283] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2023] [Revised: 08/29/2023] [Accepted: 08/29/2023] [Indexed: 09/08/2023] Open
Abstract
Arf GTPases are central regulators of the Golgi complex, which serves as the nexus of membrane-trafficking pathways in eukaryotic cells. Arf proteins recruit dozens of effectors to modify membranes, sort cargos, and create and tether transport vesicles, and are therefore essential for orchestrating Golgi trafficking. The regulation of Arf activity is controlled by the action of Arf-GEFs which activate via nucleotide exchange, and Arf-GAPs which inactivate via nucleotide hydrolysis. The localization dynamics of Arf GTPases and their Arf-GAPs during Golgi maturation have not been reported. Here we use the budding yeast model to examine the temporal localization of the Golgi Arf-GAPs. We also determine the mechanisms used by the Arf-GAP Age2 to localize to the Golgi. We find that the catalytic activity of Age2 and a conserved sequence in the unstructured C-terminal domain of Age2 are both required for Golgi localization. This sequence is predicted to form an amphipathic helix and mediates direct binding of Age2 to membranes in vitro. We also report the development of a probe for sensing active Arf1 in living cells and use this probe to characterize the temporal dynamics of Arf1 during Golgi maturation.
Collapse
Affiliation(s)
- Kaitlyn M. Manzer
- Department of Molecular Biology & Genetics, Weill Institute for Cell and Molecular Biology, Cornell University, Ithaca, NY 14850
| | - J. Christopher Fromme
- Department of Molecular Biology & Genetics, Weill Institute for Cell and Molecular Biology, Cornell University, Ithaca, NY 14850
| |
Collapse
|
5
|
Manzer KM, Fromme JC. The Arf-GAP Age2 localizes to the late-Golgi via a conserved amphipathic helix. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.07.23.550229. [PMID: 37546741 PMCID: PMC10402032 DOI: 10.1101/2023.07.23.550229] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/08/2023]
Abstract
Arf GTPases are central regulators of the Golgi complex, which serves as the nexus of membrane trafficking pathways in eukaryotic cells. Arf proteins recruit dozens of effectors to modify membranes, sort cargos, and create and tether transport vesicles, and are therefore essential for orchestrating Golgi trafficking. The regulation of Arf activity is controlled by the action of Arf-GEFs, which activate via nucleotide exchange, and Arf-GAPs, which inactivate via nucleotide hydrolysis. The localization dynamics of Arf GTPases and their Arf-GAPs during Golgi maturation have not been reported. Here we use the budding yeast model to examine the temporal localization of the Golgi Arf-GAPs. We also determine the mechanisms used by the Arf-GAP Age2 to localize to the Golgi. We find that the catalytic activity of Age2 and a conserved sequence in the unstructured C-terminal domain of Age2 are both required for Golgi localization. This sequence is predicted to form an amphipathic helix and mediates direct binding of Age2 to membranes in vitro . We also report the development of a probe for sensing active Arf1 in living cells and use this probe to characterize the temporal dynamics of Arf1 during Golgi maturation.
Collapse
Affiliation(s)
- Kaitlyn M Manzer
- Department of Molecular Biology & Genetics and Weill Institute for Cell and Molecular Biology, Cornell University, Ithaca, NY 14850 USA
| | - J Christopher Fromme
- Department of Molecular Biology & Genetics and Weill Institute for Cell and Molecular Biology, Cornell University, Ithaca, NY 14850 USA
| |
Collapse
|
6
|
Li FL, Guan KL. The Arf family GTPases: Regulation of vesicle biogenesis and beyond. Bioessays 2023; 45:e2200214. [PMID: 36998106 PMCID: PMC10282109 DOI: 10.1002/bies.202200214] [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: 11/05/2022] [Revised: 03/16/2023] [Accepted: 03/17/2023] [Indexed: 04/01/2023]
Abstract
The Arf family proteins are best known for their roles in the vesicle biogenesis. However, they also play fundamental roles in a wide range of cellular regulation besides vesicular trafficking, such as modulation of lipid metabolic enzymes, cytoskeleton remodeling, ciliogenesis, lysosomal, and mitochondrial morphology and functions. Growing studies continue to expand the downstream effector landscape of Arf proteins, especially for the less-studied members, revealing new biological functions, such as amino acid sensing. Experiments with cutting-edge technologies and in vivo functional studies in the last decade help to provide a more comprehensive view of Arf family functions. In this review, we summarize the cellular functions that are regulated by at least two different Arf members with an emphasis on those beyond vesicle biogenesis.
Collapse
Affiliation(s)
- Fu-Long Li
- College of Life Sciences, Zhejiang University, Hangzhou, Zhejiang, China
| | - Kun-Liang Guan
- Department of Pharmacology and Moores Cancer Center, University of California San Diego, La Jolla, CA, USA
| |
Collapse
|
7
|
Nawrotek A, Dubois P, Zeghouf M, Cherfils J. Molecular principles of bidirectional signalling between membranes and small GTPases. FEBS Lett 2023; 597:778-793. [PMID: 36700390 DOI: 10.1002/1873-3468.14585] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2022] [Revised: 12/23/2022] [Accepted: 12/30/2022] [Indexed: 01/27/2023]
Abstract
Most small GTPases actuate their functions on subcellular membranes, which are increasingly seen as integral components of small GTPase signalling. In this review, we used the highly studied regulation of Arf GTPases by their GEFs to categorize the molecular principles of membrane contributions to small GTPase signalling, which have been highlighted by integrated structural biology combining in vitro reconstitutions in artificial membranes and high-resolution structures. As an illustration of how this framework can be harnessed to better understand the cooperation between small GTPases, their regulators and membranes, we applied it to the activation of the small GTPase Rac1 by DOCK-ELMO, identifying novel contributions of membranes to Rac1 activation. We propose that these structure-based principles should be considered when interrogating the mechanisms whereby small GTPase systems ensure spatial and temporal control of cellular signalling on membranes.
Collapse
Affiliation(s)
- Agata Nawrotek
- CNRS, Ecole Normale Supérieure Paris-Saclay and Université Paris-Saclay, Gif-sur-Yvette, France
| | - Pavlina Dubois
- CNRS, Ecole Normale Supérieure Paris-Saclay and Université Paris-Saclay, Gif-sur-Yvette, France
| | - Mahel Zeghouf
- CNRS, Ecole Normale Supérieure Paris-Saclay and Université Paris-Saclay, Gif-sur-Yvette, France
| | - Jacqueline Cherfils
- CNRS, Ecole Normale Supérieure Paris-Saclay and Université Paris-Saclay, Gif-sur-Yvette, France
| |
Collapse
|
8
|
Chen KJ, Hsu JW, Lee FJS. AMPK promotes Arf6 activation in a kinase-independent manner upon energy deprivation. J Cell Sci 2022; 135:276453. [PMID: 36017701 PMCID: PMC9584350 DOI: 10.1242/jcs.259609] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2021] [Accepted: 08/10/2022] [Indexed: 11/20/2022] Open
Abstract
AMP-activated protein kinase (AMPK) is a crucial cellular nutrient and energy sensor that maintains energy homeostasis. AMPK also governs cancer cell invasion and migration by regulating gene expression and activating multiple cellular signaling pathways. ADP-ribosylation factor 6 (Arf6) can be activated via nucleotide exchange by guanine-nucleotide-exchange factors (GEFs), and its activation also regulates tumor invasion and migration. By studying GEF-mediated Arf6 activation, we have elucidated that AMPK functions as a noncanonical GEF for Arf6 in a kinase-independent manner. Moreover, by examining the physiological role of the AMPK–Arf6 axis, we have determined that AMPK activates Arf6 upon glucose starvation and 5-aminoimidazole-4-carboxamide-1-β-D-ribofuranoside (AICAR) treatment. We have further identified the binding motif in the C-terminal regulatory domain of AMPK that is responsible for promoting Arf6 activation and, thus, inducing cell migration and invasion. These findings reveal a noncanonical role of AMPK in which its C-terminal regulatory domain serves as a GEF for Arf6 during glucose deprivation.
Collapse
Affiliation(s)
- Kuan-Jung Chen
- Institute of Molecular Medicine, National Taiwan University, Taipei, Taiwan.,Center of Precision Medicine, College of Medicine, National Taiwan University, Taipei, Taiwan
| | - Jia-Wei Hsu
- Institute of Molecular Medicine, National Taiwan University, Taipei, Taiwan.,Institute of Biochemical Sciences, College of Life Science, National Taiwan University, Taipei, Taiwan.,Institute of Biological Chemistry, Academia Sinica, Taipei, Taiwan
| | - Fang-Jen S Lee
- Institute of Molecular Medicine, National Taiwan University, Taipei, Taiwan.,Center of Precision Medicine, College of Medicine, National Taiwan University, Taipei, Taiwan.,Department of Medical Research, National Taiwan University Hospital, Taipei, Taiwan
| |
Collapse
|
9
|
The ADP-Ribosylation Factor 4d Restricts Regulatory T-Cell Induction via Control of IL-2 Availability. Cells 2022; 11:cells11172639. [PMID: 36078047 PMCID: PMC9454872 DOI: 10.3390/cells11172639] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2022] [Revised: 08/17/2022] [Accepted: 08/23/2022] [Indexed: 11/21/2022] Open
Abstract
Interleukin-2 is central to the induction and maintenance of both natural (nTreg) and induced Foxp3-expressing regulatory T cells (iTreg). Thus, signals that modulate IL-2 availability may, in turn, also influence Treg homeostasis. Using global knockout and cell-specific knockout mouse models, we evaluated the role of the small GTPase ADP-ribosylation factor 4d (Arl4d) in regulatory T-cell biology. We show that the expression of Arl4d in T cells restricts both IL-2 production and responsiveness to IL-2, as measured by the phosphorylation of STAT5. Arl4d-deficient CD4 T cells converted more efficiently into Foxp3+ iTreg in vitro in the presence of αCD3ε and TGFβ, which was associated with their enhanced IL-2 secretion. As such, Arl4d−/− CD4 T cells induced significantly less colonic inflammation and lymphocytic infiltration in a model of transfer colitis. Thus, our data reveal a negative regulatory role for Arl4d in CD4 T-cell biology, limiting iTreg conversion via the restriction of IL-2 production, leading to reduced induction of Treg from conventional CD4 T cells.
Collapse
|
10
|
Phosphorylation of Arl4A/D promotes their binding by the HYPK chaperone for their stable recruitment to the plasma membrane. Proc Natl Acad Sci U S A 2022; 119:e2207414119. [PMID: 35857868 PMCID: PMC9335210 DOI: 10.1073/pnas.2207414119] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The Arl4 small GTPases participate in a variety of cellular events, including cytoskeleton remodeling, vesicle trafficking, cell migration, and neuronal development. Whereas small GTPases are typically regulated by their GTPase cycle, Arl4 proteins have been found to act independent of this canonical regulatory mechanism. Here, we show that Arl4A and Arl4D (Arl4A/D) are unstable due to proteasomal degradation, but stimulation of cells by fibronectin (FN) inhibits this degradation to promote Arl4A/D stability. Proteomic analysis reveals that FN stimulation induces phosphorylation at S143 of Arl4A and at S144 of Arl4D. We identify Pak1 as the responsible kinase for these phosphorylations. Moreover, these phosphorylations promote the chaperone protein HYPK to bind Arl4A/D, which stabilizes their recruitment to the plasma membrane to promote cell migration. These findings not only advance a major mechanistic understanding of how Arl4 proteins act in cell migration but also achieve a fundamental understanding of how these small GTPases are modulated by revealing that protein stability, rather than the GTPase cycle, acts as a key regulatory mechanism.
Collapse
|
11
|
Sharma R, Frasch MG, Zelgert C, Zimmermann P, Fabre B, Wilson R, Waldenberger M, MacDonald JW, Bammler TK, Lobmaier SM, Antonelli MC. Maternal-fetal stress and DNA methylation signatures in neonatal saliva: an epigenome-wide association study. Clin Epigenetics 2022; 14:87. [PMID: 35836289 PMCID: PMC9281078 DOI: 10.1186/s13148-022-01310-x] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2022] [Accepted: 07/05/2022] [Indexed: 01/02/2023] Open
Abstract
BACKGROUND Maternal stress before, during and after pregnancy has profound effects on the development and lifelong function of the infant's neurocognitive development. We hypothesized that the programming of the central nervous system (CNS), hypothalamic-pituitary-adrenal (HPA) axis and autonomic nervous system (ANS) induced by prenatal stress (PS) is reflected in electrophysiological and epigenetic biomarkers. In this study, we aimed to find noninvasive epigenetic biomarkers of PS in the newborn salivary DNA. RESULTS A total of 728 pregnant women were screened for stress exposure using Cohen Perceived Stress Scale (PSS), 164 women were enrolled, and 114 dyads were analyzed. Prenatal Distress Questionnaire (PDQ) was also administered to assess specific pregnancy worries. Transabdominal fetal electrocardiograms (taECG) were recorded to derive coupling between maternal and fetal heart rates resulting in a 'Fetal Stress Index' (FSI). Upon delivery, we collected maternal hair strands for cortisol measurements and newborn's saliva for epigenetic analyses. DNA was extracted from saliva samples, and DNA methylation was measured using EPIC BeadChip array (850 k CpG sites). Linear regression was used to identify associations between PSS/PDQ/FSI/Cortisol and DNA methylation. We found epigenome-wide significant associations for 5 CpG with PDQ and cortisol at FDR < 5%. Three CpGs were annotated to genes (Illumina Gene annotation file): YAP1, TOMM20 and CSMD1, and two CpGs were located approximately lay at 50 kb from SSBP4 and SCAMP1. In addition, two differentiated methylation regions (DMR) related to maternal stress measures PDQ and cortisol were found: DAXX and ARL4D. CONCLUSIONS Genes annotated to these CpGs were found to be involved in secretion and transportation, nuclear signaling, Hippo signaling pathways, apoptosis, intracellular trafficking and neuronal signaling. Moreover, some CpGs are annotated to genes related to autism, post-traumatic stress disorder (PTSD) and schizophrenia. However, our results should be viewed as hypothesis generating until replicated in a larger sample. Early assessment of such noninvasive PS biomarkers will allow timelier detection of babies at risk and a more effective allocation of resources for early intervention programs to improve child development. A biomarker-guided early intervention strategy is the first step in the prevention of future health problems, reducing their personal and societal impact.
Collapse
Affiliation(s)
- Ritika Sharma
- Department of Obstetrics and Gynecology, Klinikum Rechts der Isar, Technical University of Munich, Munich, Germany
- Research Unit of Molecular Epidemiology, Institute of Epidemiology, Helmholtz Zentrum Munich, Munich, Germany
| | - Martin G Frasch
- Department of Obstetrics and Gynecology and Center On Human Development and Disability (CHDD), University of Washington, Seattle, WA, USA
| | - Camila Zelgert
- Department of Obstetrics and Gynecology, Klinikum Rechts der Isar, Technical University of Munich, Munich, Germany
| | - Peter Zimmermann
- Department of Obstetrics and Gynecology, Klinikum Rechts der Isar, Technical University of Munich, Munich, Germany
| | - Bibiana Fabre
- Instituto de Fisiopatología y Bioquímica Clínica (INFIBIOC), Facultad de Farmacia y Bioquímica, Universidad de Buenos Aires, Buenos Aires, Argentina
| | - Rory Wilson
- Research Unit of Molecular Epidemiology, Institute of Epidemiology, Helmholtz Zentrum Munich, Munich, Germany
| | - Melanie Waldenberger
- Research Unit of Molecular Epidemiology, Institute of Epidemiology, Helmholtz Zentrum Munich, Munich, Germany
| | - James W MacDonald
- Department of Environmental and Occupational Health Sciences, University of Washington, Seattle, WA, USA
| | - Theo K Bammler
- Department of Environmental and Occupational Health Sciences, University of Washington, Seattle, WA, USA
| | - Silvia M Lobmaier
- Department of Obstetrics and Gynecology, Klinikum Rechts der Isar, Technical University of Munich, Munich, Germany
| | - Marta C Antonelli
- Department of Obstetrics and Gynecology, Klinikum Rechts der Isar, Technical University of Munich, Munich, Germany.
- Instituto de Biología Celular y Neurociencia "Prof. E. De Robertis", Facultad de Medicina, Universidad de Buenos Aires, Buenos Aires, Argentina.
| |
Collapse
|
12
|
Ito A, Fukaya M, Okamoto H, Sakagami H. Physiological and Pathological Roles of the Cytohesin Family in Neurons. Int J Mol Sci 2022; 23:5087. [PMID: 35563476 PMCID: PMC9104363 DOI: 10.3390/ijms23095087] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2022] [Revised: 05/01/2022] [Accepted: 05/02/2022] [Indexed: 02/05/2023] Open
Abstract
The cytohesin proteins, consisting of four closely related members (cytohesins-1, -2, -3, and -4), are a subfamily of the Sec7 domain-containing guanine nucleotide exchange factors for ADP ribosylation factors (Arfs), which are critical regulators of membrane trafficking and actin cytoskeleton remodeling. Recent advances in molecular biological techniques and the development of a specific pharmacological inhibitor for cytohesins, SecinH3, have revealed the functional involvement of the cytohesin-Arf pathway in diverse neuronal functions from the formation of axons and dendrites, axonal pathfinding, and synaptic vesicle recycling, to pathophysiological processes including chronic pain and neurotoxicity induced by proteins related to neurodegenerative disorders, such as amyotrophic lateral sclerosis and Alzheimer's disease. Here, we review the physiological and pathological roles of the cytohesin-Arf pathway in neurons and discuss the future directions of this research field.
Collapse
Affiliation(s)
- Akiko Ito
- Department of Anesthesiology, Kitasato University School of Medicine, Sagamihara 252-0374, Kanagawa, Japan; (A.I.); (H.O.)
- Department of Anatomy, Kitasato University School of Medicine, Sagamihara 252-0374, Kanagawa, Japan;
| | - Masahiro Fukaya
- Department of Anatomy, Kitasato University School of Medicine, Sagamihara 252-0374, Kanagawa, Japan;
| | - Hirotsugu Okamoto
- Department of Anesthesiology, Kitasato University School of Medicine, Sagamihara 252-0374, Kanagawa, Japan; (A.I.); (H.O.)
| | - Hiroyuki Sakagami
- Department of Anatomy, Kitasato University School of Medicine, Sagamihara 252-0374, Kanagawa, Japan;
| |
Collapse
|
13
|
Hammond GRV, Ricci MMC, Weckerly CC, Wills RC. An update on genetically encoded lipid biosensors. Mol Biol Cell 2022; 33:tp2. [PMID: 35420888 PMCID: PMC9282013 DOI: 10.1091/mbc.e21-07-0363] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2021] [Revised: 02/15/2022] [Accepted: 02/16/2022] [Indexed: 01/16/2023] Open
Abstract
Specific lipid species play central roles in cell biology. Their presence or enrichment in individual membranes can control properties or direct protein localization and/or activity. Therefore, probes to detect and observe these lipids in intact cells are essential tools in the cell biologist's freezer box. Herein, we discuss genetically encoded lipid biosensors, which can be expressed as fluorescent protein fusions to track lipids in living cells. We provide a state-of-the-art list of the most widely available and reliable biosensors and highlight new probes (circa 2018-2021). Notably, we focus on advances in biosensors for phosphatidylinositol, phosphatidic acid, and PI 3-kinase lipid products.
Collapse
Affiliation(s)
- Gerald R. V. Hammond
- Department of Cell Biology, University of Pittsburgh School of Medicine, Pittsburgh, PA 15261
| | - Morgan M. C. Ricci
- Department of Cell Biology, University of Pittsburgh School of Medicine, Pittsburgh, PA 15261
| | - Claire C. Weckerly
- Department of Cell Biology, University of Pittsburgh School of Medicine, Pittsburgh, PA 15261
| | - Rachel C. Wills
- Department of Cell Biology, University of Pittsburgh School of Medicine, Pittsburgh, PA 15261
| |
Collapse
|
14
|
Yi C, Cai C, Cheng Z, Zhao Y, Yang X, Wu Y, Wang X, Jin Z, Xiang Y, Jin M, Han L, Zhang A. Genome-wide CRISPR-Cas9 screening identifies the CYTH2 host gene as a potential therapeutic target of influenza viral infection. Cell Rep 2022; 38:110559. [PMID: 35354039 DOI: 10.1016/j.celrep.2022.110559] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2021] [Revised: 01/06/2022] [Accepted: 03/01/2022] [Indexed: 11/28/2022] Open
Abstract
Host genes critical for viral infection are effective antiviral drug targets with tremendous potential due to their universal characteristics against different subtypes of viruses and minimization of drug resistance. Accordingly, we execute a genome-wide CRISPR-Cas9 screen with multiple rounds of survival selection. Enriched in this screen are several genes critical for host sialic acid biosynthesis and transportation, including the cytohesin 2 (CYTH2), tetratricopeptide repeat protein 24 (TTC24), and N-acetylneuraminate synthase (NANS), which we confirm are responsible for efficient influenza viral infection. Moreover, we reveal that CYTH2 is required for the early stage of influenza virus infection by mediating endosomal trafficking. Furthermore, CYTH2 antagonist SecinH3 blunts influenza virus infection in vivo. In summary, these data suggest that CYTH2 is an attractive target for developing host-directed antiviral drugs and therapeutics against influenza virus infection.
Collapse
Affiliation(s)
- Chenyang Yi
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Hubei Hongshan Laboratory, Huazhong Agricultural University, Wuhan, Hubei 430070, China; Key Laboratory of Preventive Veterinary Medicine in Hubei Province, The Cooperative Innovation Center for Sustainable Pig Production, Wuhan, Hubei 430070, China
| | - Cong Cai
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Hubei Hongshan Laboratory, Huazhong Agricultural University, Wuhan, Hubei 430070, China; Key Laboratory of Preventive Veterinary Medicine in Hubei Province, The Cooperative Innovation Center for Sustainable Pig Production, Wuhan, Hubei 430070, China
| | - Ze Cheng
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Hubei Hongshan Laboratory, Huazhong Agricultural University, Wuhan, Hubei 430070, China; Key Laboratory of Preventive Veterinary Medicine in Hubei Province, The Cooperative Innovation Center for Sustainable Pig Production, Wuhan, Hubei 430070, China
| | - Yifan Zhao
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Hubei Hongshan Laboratory, Huazhong Agricultural University, Wuhan, Hubei 430070, China; Key Laboratory of Preventive Veterinary Medicine in Hubei Province, The Cooperative Innovation Center for Sustainable Pig Production, Wuhan, Hubei 430070, China
| | - Xu Yang
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Hubei Hongshan Laboratory, Huazhong Agricultural University, Wuhan, Hubei 430070, China; Key Laboratory of Preventive Veterinary Medicine in Hubei Province, The Cooperative Innovation Center for Sustainable Pig Production, Wuhan, Hubei 430070, China
| | - Yue Wu
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Hubei Hongshan Laboratory, Huazhong Agricultural University, Wuhan, Hubei 430070, China; Key Laboratory of Preventive Veterinary Medicine in Hubei Province, The Cooperative Innovation Center for Sustainable Pig Production, Wuhan, Hubei 430070, China
| | - Xiaoping Wang
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Hubei Hongshan Laboratory, Huazhong Agricultural University, Wuhan, Hubei 430070, China; Key Laboratory of Preventive Veterinary Medicine in Hubei Province, The Cooperative Innovation Center for Sustainable Pig Production, Wuhan, Hubei 430070, China
| | - Zehua Jin
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Hubei Hongshan Laboratory, Huazhong Agricultural University, Wuhan, Hubei 430070, China; Key Laboratory of Preventive Veterinary Medicine in Hubei Province, The Cooperative Innovation Center for Sustainable Pig Production, Wuhan, Hubei 430070, China
| | - Yaozu Xiang
- Shanghai East Hospital, School of Life Sciences and Technology, Tongji University, Shanghai 200000, China
| | - Meilin Jin
- Key Laboratory of Preventive Veterinary Medicine in Hubei Province, The Cooperative Innovation Center for Sustainable Pig Production, Wuhan, Hubei 430070, China; Key Laboratory of Development of Veterinary Diagnostic Products, Ministry of Agriculture of the People's Republic of China, Wuhan, Hubei 430070, China
| | - Li Han
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Hubei Hongshan Laboratory, Huazhong Agricultural University, Wuhan, Hubei 430070, China
| | - Anding Zhang
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Hubei Hongshan Laboratory, Huazhong Agricultural University, Wuhan, Hubei 430070, China; Key Laboratory of Preventive Veterinary Medicine in Hubei Province, The Cooperative Innovation Center for Sustainable Pig Production, Wuhan, Hubei 430070, China; Key Laboratory of Development of Veterinary Diagnostic Products, Ministry of Agriculture of the People's Republic of China, Wuhan, Hubei 430070, China.
| |
Collapse
|
15
|
Wang Y, Çil Ç, Harnett MM, Pineda MA. Cytohesin-2/ARNO: A Novel Bridge Between Cell Migration and Immunoregulation in Synovial Fibroblasts. Front Immunol 2022; 12:809896. [PMID: 35095899 PMCID: PMC8790574 DOI: 10.3389/fimmu.2021.809896] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2021] [Accepted: 12/17/2021] [Indexed: 11/26/2022] Open
Abstract
The guanine nucleotide exchange factor cytohesin-2 (ARNO) is a major activator of the small GTPase ARF6 that has been shown to play an important role(s) in cell adhesion, migration and cytoskeleton reorganization in various cell types and models of disease. Interestingly, dysregulated cell migration, in tandem with hyper-inflammatory responses, is one of the hallmarks associated with activated synovial fibroblasts (SFs) during chronic inflammatory joint diseases, like rheumatoid arthritis. The role of ARNO in this process has previously been unexplored but we hypothesized that the pro-inflammatory milieu of inflamed joints locally induces activation of ARNO-mediated pathways in SFs, promoting an invasive cell phenotype that ultimately leads to bone and cartilage damage. Thus, we used small interference RNA to investigate the impact of ARNO on the pathological migration and inflammatory responses of murine SFs, revealing a fully functional ARNO-ARF6 pathway which can be rapidly activated by IL-1β. Such signalling promotes cell migration and formation of focal adhesions. Unexpectedly, ARNO was also shown to modulate SF-inflammatory responses, dictating their precise cytokine and chemokine expression profile. Our results uncover a novel role for ARNO in SF-dependent inflammation, that potentially links pathogenic migration with initiation of local joint inflammation, offering new approaches for targeting the fibroblast compartment in chronic arthritis and joint disease.
Collapse
Affiliation(s)
- Yilin Wang
- Institute of Infection, Immunity and Inflammation, University of Glasgow, Glasgow, United Kingdom
| | - Çağlar Çil
- Institute of Infection, Immunity and Inflammation, University of Glasgow, Glasgow, United Kingdom
| | - Margaret M Harnett
- Institute of Infection, Immunity and Inflammation, University of Glasgow, Glasgow, United Kingdom
| | - Miguel A Pineda
- Institute of Infection, Immunity and Inflammation, University of Glasgow, Glasgow, United Kingdom.,Research Into Inflammatory Arthritis Centre Versus Arthritis (RACE), Glasgow, United Kingdom
| |
Collapse
|
16
|
Li T, Guo Y. ADP-Ribosylation Factor Family of Small GTP-Binding Proteins: Their Membrane Recruitment, Activation, Crosstalk and Functions. Front Cell Dev Biol 2022; 10:813353. [PMID: 35186926 PMCID: PMC8850633 DOI: 10.3389/fcell.2022.813353] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2021] [Accepted: 01/14/2022] [Indexed: 11/13/2022] Open
Abstract
Members of the ADP-ribosylation factor (ARF) family of guanine-nucleotide binding proteins play critical roles in various cellular processes, especially in regulating the secretory, and endocytic pathways. The fidelity of intracellular vesicular trafficking depends on proper activations and precise subcellular distributions of ARF family proteins regulated by guanine nucleotide exchange factors (GEFs) and GTPase-activating proteins (GAPs). Here we review recent progress in understanding the membrane recruitment, activation, crosstalk, and functions of ARF family proteins.
Collapse
Affiliation(s)
- Tiantian Li
- Division of Life Science and State Key Laboratory of Molecular Neuroscience, The Hong Kong University of Science and Technology, Kowloon, Hong Kong SAR, China
| | - Yusong Guo
- Division of Life Science and State Key Laboratory of Molecular Neuroscience, The Hong Kong University of Science and Technology, Kowloon, Hong Kong SAR, China
- Hong Kong University of Science and Technology, Shenzhen Research Institute, Shenzhen, China
- Southern Marine Science and Engineering Guangdong Laboratory (Guangzhou), Guangzhou, China
- *Correspondence: Yusong Guo,
| |
Collapse
|
17
|
Vargová R, Wideman JG, Derelle R, Klimeš V, Kahn RA, Dacks JB, Eliáš M. A Eukaryote-Wide Perspective on the Diversity and Evolution of the ARF GTPase Protein Family. Genome Biol Evol 2021; 13:6319025. [PMID: 34247240 PMCID: PMC8358228 DOI: 10.1093/gbe/evab157] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/02/2021] [Indexed: 12/21/2022] Open
Abstract
The evolution of eukaryotic cellular complexity is interwoven with the extensive diversification of many protein families. One key family is the ARF GTPases that act in eukaryote-specific processes, including membrane traffic, tubulin assembly, actin dynamics, and cilia-related functions. Unfortunately, our understanding of the evolution of this family is limited. Sampling an extensive set of available genome and transcriptome sequences, we have assembled a data set of over 2,000 manually curated ARF family genes from 114 eukaryotic species, including many deeply diverged protist lineages, and carried out comprehensive molecular phylogenetic analyses. These reconstructed as many as 16 ARF family members present in the last eukaryotic common ancestor, nearly doubling the previously inferred ancient system complexity. Evidence for the wide occurrence and ancestral origin of Arf6, Arl13, and Arl16 is presented for the first time. Moreover, Arl17, Arl18, and SarB, newly described here, are absent from well-studied model organisms and as a result their function(s) remain unknown. Analyses of our data set revealed a previously unsuspected diversity of membrane association modes and domain architectures within the ARF family. We detail the step-wise expansion of the ARF family in the metazoan lineage, including discovery of several new animal-specific family members. Delving back to its earliest evolution in eukaryotes, the resolved relationship observed between the ARF family paralogs sets boundaries for scenarios of vesicle coat origins during eukaryogenesis. Altogether, our work fundamentally broadens the understanding of the diversity and evolution of a protein family underpinning the structural and functional complexity of the eukaryote cells.
Collapse
Affiliation(s)
- Romana Vargová
- Department of Biology and Ecology, Faculty of Science, University of Ostrava, Czech Republic
| | - Jeremy G Wideman
- Biodesign Center for Mechanisms of Evolution, School of Life Sciences, Arizona State University, Tempe, Arizona, USA
| | - Romain Derelle
- Station d'Ecologie Théorique et Expérimentale, UMR CNRS 5321, Moulis, France
| | - Vladimír Klimeš
- Department of Biology and Ecology, Faculty of Science, University of Ostrava, Czech Republic
| | - Richard A Kahn
- Department of Biochemistry, Emory University School of Medicine, Atlanta, Georgia, USA
| | - Joel B Dacks
- Division of Infectious Disease, Department of Medicine, University of Alberta, Edmonton, Alberta, Canada.,Centre for Life's Origin and Evolution, Department of Genetics, Evolution and Environment, University College of London, United Kingdom
| | - Marek Eliáš
- Department of Biology and Ecology, Faculty of Science, University of Ostrava, Czech Republic
| |
Collapse
|
18
|
Wu SH, Chang MH, Chen YH, Wu HL, Chua HH, Chien CS, Ni YH, Chen HL, Chen HL. The ESCRT-III molecules regulate the apical targeting of bile salt export pump. J Biomed Sci 2021; 28:19. [PMID: 33750401 PMCID: PMC7941988 DOI: 10.1186/s12929-020-00706-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2020] [Accepted: 12/30/2020] [Indexed: 11/17/2022] Open
Abstract
Background The bile salt export pump (BSEP) is a pivotal apical/canalicular bile salt transporter in hepatocytes that drives the bile flow. Defects in BSEP function and canalicular expression could lead to a spectrum of cholestatic liver diseases. One prominent manifestation of BSEP-associated cholestasis is the defective canalicular localization and cytoplasmic retention of BSEP. However, the etiology of impaired BSEP targeting to the canalicular membrane is not fully understood. Our goal was to discover what molecule could interact with BSEP and affect its post-Golgi sorting. Methods The human BSEP amino acids (a.a.) 491-630 was used as bait to screen a human fetal liver cDNA library through yeast two-hybrid system. We identified a BSEP-interacting candidate and showed the interaction and colocalization in the co-immunoprecipitation in hepatoma cell lines and histological staining in human liver samples. Temperature shift assays were used to study the post-Golgi trafficking of BSEP. We further determine the functional impacts of the BSEP-interacting candidate on BSEP in vitro. A hydrodynamically injected mouse model was established for in vivo characterizing the long-term impacts on BSEP. Results We identified that charged multivesicular body protein 5 (CHMP5), a molecule of the endosomal protein complex required for transport subcomplex-III (ESCRT-III), interacted and co-localized with BSEP in the subapical compartments (SACs) in developing human livers. Cholestatic BSEP mutations in the CHMP5-interaction region have defects in canalicular targeting and aberrant retention at the SACs. Post-Golgi delivery of BSEP and bile acid secretion were impaired in ESCRT-III perturbation or CHMP5-knockdown hepatic cellular and mouse models. This ESCRT-III-mediated BSEP sorting preceded Rab11A-regulated apical cycling of BSEP. Conclusions Our results showed the first example that ESCRT-III is essential for canalicular trafficking of apical membrane proteins, and provide new targets for therapeutic approaches in BSEP associated cholestasis.
Collapse
Affiliation(s)
- Shang-Hsin Wu
- Graduate Institute of Clinical Medicine, National Taiwan University College of Medicine, Taipei, 100, Taiwan
| | - Mei-Hwei Chang
- Graduate Institute of Clinical Medicine, National Taiwan University College of Medicine, Taipei, 100, Taiwan.,Department of Pediatrics, National Taiwan University College of Medicine and National Taiwan University Children's Hospital, Taipei, 100, Taiwan.,Hepatitis Research Center, National Taiwan University Hospital, Taipei, 100, Taiwan
| | - Ya-Hui Chen
- Department of Pediatrics, National Taiwan University College of Medicine and National Taiwan University Children's Hospital, Taipei, 100, Taiwan
| | - Hui-Lin Wu
- Graduate Institute of Clinical Medicine, National Taiwan University College of Medicine, Taipei, 100, Taiwan.,Hepatitis Research Center, National Taiwan University Hospital, Taipei, 100, Taiwan
| | - Huey-Huey Chua
- Department of Pediatrics, National Taiwan University College of Medicine and National Taiwan University Children's Hospital, Taipei, 100, Taiwan
| | - Chin-Sung Chien
- Graduate Institute of Clinical Medicine, National Taiwan University College of Medicine, Taipei, 100, Taiwan
| | - Yen-Hsuan Ni
- Department of Pediatrics, National Taiwan University College of Medicine and National Taiwan University Children's Hospital, Taipei, 100, Taiwan.,Hepatitis Research Center, National Taiwan University Hospital, Taipei, 100, Taiwan.,Medical Microbiota Center of the First Core Laboratory, National Taiwan University College of Medicine, Taipei, 100, Taiwan
| | - Hui-Ling Chen
- Hepatitis Research Center, National Taiwan University Hospital, Taipei, 100, Taiwan.
| | - Huey-Ling Chen
- Department of Pediatrics, National Taiwan University College of Medicine and National Taiwan University Children's Hospital, Taipei, 100, Taiwan. .,Hepatitis Research Center, National Taiwan University Hospital, Taipei, 100, Taiwan. .,Department and Graduate Institute of Medical Education and Bioethics, National Taiwan University College of Medicine, Taipei, 100, Taiwan.
| |
Collapse
|
19
|
Montaño-Rendón F, Grinstein S, Walpole GFW. Monitoring Phosphoinositide Fluxes and Effectors During Leukocyte Chemotaxis and Phagocytosis. Front Cell Dev Biol 2021; 9:626136. [PMID: 33614656 PMCID: PMC7890364 DOI: 10.3389/fcell.2021.626136] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2020] [Accepted: 01/06/2021] [Indexed: 01/22/2023] Open
Abstract
The dynamic re-organization of cellular membranes in response to extracellular stimuli is fundamental to the cell physiology of myeloid and lymphoid cells of the immune system. In addition to maintaining cellular homeostatic functions, remodeling of the plasmalemma and endomembranes endow leukocytes with the potential to relay extracellular signals across their biological membranes to promote rolling adhesion and diapedesis, migration into the tissue parenchyma, and to ingest foreign particles and effete cells. Phosphoinositides, signaling lipids that control the interface of biological membranes with the external environment, are pivotal to this wealth of functions. Here, we highlight the complex metabolic transitions that occur to phosphoinositides during several stages of the leukocyte lifecycle, namely diapedesis, migration, and phagocytosis. We describe classical and recently developed tools that have aided our understanding of these complex lipids. Finally, major downstream effectors of inositides are highlighted including the cytoskeleton, emphasizing the importance of these rare lipids in immunity and disease.
Collapse
Affiliation(s)
- Fernando Montaño-Rendón
- Program in Cell Biology, Hospital for Sick Children, Toronto, ON, Canada.,Institute of Medical Sciences, University of Toronto, Toronto, ON, Canada
| | - Sergio Grinstein
- Program in Cell Biology, Hospital for Sick Children, Toronto, ON, Canada.,Institute of Medical Sciences, University of Toronto, Toronto, ON, Canada.,Department of Biochemistry, University of Toronto, Toronto, ON, Canada.,Keenan Research Centre for Biomedical Science, St. Michael's Hospital, Toronto, ON, Canada
| | - Glenn F W Walpole
- Program in Cell Biology, Hospital for Sick Children, Toronto, ON, Canada.,Department of Biochemistry, University of Toronto, Toronto, ON, Canada
| |
Collapse
|
20
|
Abstract
Lipids, like phosphoinositides, can be visualized in living cells in real time using genetically encoded biosensors and fluorescence microscopy. Sensor localization can be quantified by determining the fluorescence intensity of each fluorophore. Enrichment of lipids at membranes can be determined by generating and applying an organelle-specific binary mask. In this chapter, we provide a detailed list of reagents and methods to visualize and quantify relative lipid levels. Applying this approach, changes in lipid levels can be assessed in cases when lipid metabolizing enzymes are mutated or otherwise altered.
Collapse
Affiliation(s)
- Rachel C Wills
- Department of Cell Biology, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
| | - Jonathan Pacheco
- Department of Cell Biology, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
| | - Gerald R V Hammond
- Department of Cell Biology, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA.
| |
Collapse
|
21
|
Amable G, Martínez-León E, Picco ME, Nemirovsky SI, Rozengurt E, Rey O. Metformin inhibition of colorectal cancer cell migration is associated with rebuilt adherens junctions and FAK downregulation. J Cell Physiol 2020; 235:8334-8344. [PMID: 32239671 PMCID: PMC7529638 DOI: 10.1002/jcp.29677] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2019] [Accepted: 03/06/2020] [Indexed: 01/04/2023]
Abstract
E-cadherin, a central component of the adherens junction (AJ), is a single-pass transmembrane protein that mediates cell-cell adhesion. The loss of E-cadherin surface expression, and therefore cell-cell adhesion, leads to increased cell migration and invasion. Treatment of colorectal cancer (CRC)-derived cells (SW-480 and HT-29) with 2.0 mM metformin promoted a redistribution of cytosolic E-cadherin to de novo formed puncta along the length of the contacting membranes of these cells. Metformin also promoted translocation from the cytosol to the plasma membrane of p120-catenin, another core component of the AJs. Furthermore, E-cadherin and p120-catenin colocalized with β-catenin at cell-cell contacts. Western blot analysis of lysates of CRC-derived cells revealed a substantial metformin-induced increase in the level of p120-catenin as well as E-cadherin phosphorylation on Ser838/840 , a modification associated with β-catenin/E-cadherin interaction. These modifications in E-cadherin, p120-catenin and β-catenin localization suggest that metformin induces rebuilding of AJs in CRC-derived cells. Those modifications were accompanied by the inhibition of focal adhesion kinase (FAK), as revealed by a significant decrease in the phosphorylation of FAK at Tyr397 and paxillin at Tyr118 . These changes were associated with a reduction in the numbers, but an increase in the size, of focal adhesions and by the inhibition of cell migration. Overall, these observations indicate that metformin targets multiple pathways associated with CRC development and progression.
Collapse
Affiliation(s)
- Gastón Amable
- Consejo Nacional de Investigaciones Científicas y Técnicas, Universidad de Buenos Aires, Instituto de Inmunología, Genética y Metabolismo, Facultad de Farmacia y Bioquímica, Hospital de Clínicas “José de San Martín”, Ciudad Autónoma de Buenos Aires, 1120, Argentina
| | - Eduardo Martínez-León
- Consejo Nacional de Investigaciones Científicas y Técnicas, Universidad de Buenos Aires, Instituto de Inmunología, Genética y Metabolismo, Facultad de Farmacia y Bioquímica, Hospital de Clínicas “José de San Martín”, Ciudad Autónoma de Buenos Aires, 1120, Argentina
| | - María Elisa Picco
- Consejo Nacional de Investigaciones Científicas y Técnicas, Universidad de Buenos Aires, Instituto de Inmunología, Genética y Metabolismo, Facultad de Farmacia y Bioquímica, Hospital de Clínicas “José de San Martín”, Ciudad Autónoma de Buenos Aires, 1120, Argentina
| | - Sergio I. Nemirovsky
- Instituto de Química Biológica de la Facultad de Ciencias Exactas y Naturales, Consejo Nacional de Investigaciones Científicas y Técnicas, Universidad de Buenos Aires, Ciudad Autónoma de Buenos Aires, 1428EGA, Argentina
| | - Enrique Rozengurt
- Unit of Signal Transduction and Gastrointestinal Cancer, Division of Digestive Diseases, Department of Medicine, CURE: Digestive Diseases Research Center and Molecular Biology Institute, David Geffen School of Medicine, University of California at Los Angeles, CA, 90095-1768, USA
| | - Osvaldo Rey
- Consejo Nacional de Investigaciones Científicas y Técnicas, Universidad de Buenos Aires, Instituto de Inmunología, Genética y Metabolismo, Facultad de Farmacia y Bioquímica, Hospital de Clínicas “José de San Martín”, Ciudad Autónoma de Buenos Aires, 1120, Argentina
| |
Collapse
|
22
|
Lin SJ, Huang CF, Wu TS, Li CC, Lee FJS. Arl4D-EB1 interaction promotes centrosomal recruitment of EB1 and microtubule growth. Mol Biol Cell 2020; 31:2348-2362. [PMID: 32755434 PMCID: PMC7851962 DOI: 10.1091/mbc.e18-10-0611] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Abstract
ADP-ribosylation factor (Arf)-like 4D (Arl4D), one of the Arf-like small GTPases, functions in the regulation of cell morphology, cell migration, and actin cytoskeleton remodeling. End-binding 1 (EB1) is a microtubule (MT) plus-end tracking protein that preferentially localizes at the tips of the plus ends of growing MTs and at the centrosome. EB1 depletion results in many centrosome-related defects. Here, we report that Arl4D promotes the recruitment of EB1 to the centrosome and regulates MT nucleation. We first showed that Arl4D interacts with EB1 in a GTP-dependent manner. This interaction is dependent on the C-terminal EB homology region of EB1 and partially dependent on an SxLP motif of Arl4D. We found that Arl4D colocalized with γ-tubulin in centrosomes and the depletion of Arl4D resulted in a centrosomal MT nucleation defect. We further demonstrated that abolishing Arl4D-EB1 interaction decreased MT nucleation rate and diminished the centrosomal recruitment of EB1 without affecting MT growth rate. In addition, Arl4D binding to EB1 increased the association between the p150 subunit of dynactin and the EB1, which is important for MT stabilization. Together, our results indicate that Arl4D modulates MT nucleation through regulation of the EB1–p150 association at the centrosome.
Collapse
Affiliation(s)
- Shin-Jin Lin
- Institute of Molecular Medicine, National Taiwan University, 100225 Taipei, Taiwan.,Department of Medical Research, National Taiwan University Hospital, National Taiwan University, 100225 Taipei, Taiwan
| | - Chun-Fang Huang
- Institute of Molecular Medicine, National Taiwan University, 100225 Taipei, Taiwan
| | - Tsung-Sheng Wu
- Institute of Molecular Medicine, National Taiwan University, 100225 Taipei, Taiwan
| | - Chun-Chun Li
- Institute of Molecular Medicine, National Taiwan University, 100225 Taipei, Taiwan
| | - Fang-Jen S Lee
- Institute of Molecular Medicine, National Taiwan University, 100225 Taipei, Taiwan.,Center of Precision Medicine, College of Medicine, National Taiwan University, 100225 Taipei, Taiwan.,Department of Medical Research, National Taiwan University Hospital, National Taiwan University, 100225 Taipei, Taiwan
| |
Collapse
|
23
|
Casalou C, Ferreira A, Barral DC. The Role of ARF Family Proteins and Their Regulators and Effectors in Cancer Progression: A Therapeutic Perspective. Front Cell Dev Biol 2020; 8:217. [PMID: 32426352 PMCID: PMC7212444 DOI: 10.3389/fcell.2020.00217] [Citation(s) in RCA: 42] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2020] [Accepted: 03/12/2020] [Indexed: 12/13/2022] Open
Abstract
The Adenosine diphosphate-Ribosylation Factor (ARF) family belongs to the RAS superfamily of small GTPases and is involved in a wide variety of physiological processes, such as cell proliferation, motility and differentiation by regulating membrane traffic and associating with the cytoskeleton. Like other members of the RAS superfamily, ARF family proteins are activated by Guanine nucleotide Exchange Factors (GEFs) and inactivated by GTPase-Activating Proteins (GAPs). When active, they bind effectors, which mediate downstream functions. Several studies have reported that cancer cells are able to subvert membrane traffic regulators to enhance migration and invasion. Indeed, members of the ARF family, including ARF-Like (ARL) proteins have been implicated in tumorigenesis and progression of several types of cancer. Here, we review the role of ARF family members, their GEFs/GAPs and effectors in tumorigenesis and cancer progression, highlighting the ones that can have a pro-oncogenic behavior or function as tumor suppressors. Moreover, we propose possible mechanisms and approaches to target these proteins, toward the development of novel therapeutic strategies to impair tumor progression.
Collapse
Affiliation(s)
- Cristina Casalou
- CEDOC, NOVA Medical School, Faculdade de Ciências Médicas, Universidade NOVA de Lisboa, Lisbon, Portugal
| | - Andreia Ferreira
- CEDOC, NOVA Medical School, Faculdade de Ciências Médicas, Universidade NOVA de Lisboa, Lisbon, Portugal
| | - Duarte C Barral
- CEDOC, NOVA Medical School, Faculdade de Ciências Médicas, Universidade NOVA de Lisboa, Lisbon, Portugal
| |
Collapse
|
24
|
The GEF Cytohesin-2/ARNO Mediates Resistin induced Phenotypic Switching in Vascular Smooth Muscle Cells. Sci Rep 2020; 10:3672. [PMID: 32111889 PMCID: PMC7048779 DOI: 10.1038/s41598-020-60446-z] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2019] [Accepted: 02/12/2020] [Indexed: 12/27/2022] Open
Abstract
The pro-inflammatory adipokine resistin induces a phenotypic switch of vascular smooth muscle cells (VSMC), a process decisive for atherosclerosis, including morphological changes, increased synthetic activity, proliferation and migration. The guanine-exchange factor ARNO (Cytohesin-2) has been shown to be important for morphological changes and migration of other cell types. In this study we dissected the role of ARNO in resistin induced VSMC phenotypic switching and signalling. Firstly, treatment with the cytohesin inhibitor Secin H3 prevented the resistin mediated induction of morphological changes in VSMC. Secondly, Secin H3 treatment as well as expression of an inactive ARNO (EK) reduced resistin induced VSMC synthetic activity, as assessed by matrix metalloproteinase 2 (MMP-2) expression, as well as the migration into a wound in vitro compared to ARNO WT expression. Thirdly, we found ARNO to influence MMP-2 expression and migration via activation of p38 MAPK and the JNK/AP-1 pathway. Interestingly, these processes were shown to be dependent on the binding of PIP3, as mutation of the ARNO PH-domain inhibited VSMC migration, MMP-2 expression as well as p38 MAPK and JNK signalling. Thus, we demonstrate that ARNO is an important link in resistin dependent cell signalling leading to morphological changes, MMP-2 production and migration of VSMC.
Collapse
|
25
|
Kimura K, Matsumoto S, Harada T, Morii E, Nagatomo I, Shintani Y, Kikuchi A. ARL4C is associated with initiation and progression of lung adenocarcinoma and represents a therapeutic target. Cancer Sci 2020; 111:951-961. [PMID: 31925985 PMCID: PMC7060486 DOI: 10.1111/cas.14303] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2019] [Revised: 11/26/2019] [Accepted: 12/23/2019] [Indexed: 02/06/2023] Open
Abstract
Lung adenocarcinoma is the most common histological type of lung cancer and is classified into adenocarcinoma in situ (AIS), minimally invasive adenocarcinoma (MIA) and invasive adenocarcinoma (IA). Atypical adenomatous hyperplasia (AAH) lesions are possible precursors to adenocarcinoma. However, the mechanism underlying the stepwise continuum of lung adenocarcinoma is unclear. In this study, the involvement of ADP‐ribosylation factor (ARF)‐like (ARL) 4C (ARL4C), a member of the small GTP‐binding protein family, in the progression of lung adenocarcinoma and the possibility of ARL4C as a molecular target for lung cancer therapy were explored. ARL4C was frequently expressed in AAH and ARL4C expression in immortalized human small airway epithelial cells promoted cell proliferation and suppressed cell death. In addition, ARL4C was expressed with increased frequency in AIS, MIA and IA in a stage‐dependent manner, and the expression was correlated with histologic grade, fluorine‐18 fluorodeoxyglucose uptake and poor prognosis. An anti–sense oligonucleotide (ASO) against ARL4C (ARL4C ASO‐1316) inhibited RAS‐related C3 botulinum toxin substrate activity and nuclear import of Yes‐associated protein and transcriptional coactivator with PDZ‐binding motif, and suppressed in vitro proliferation and migration of lung cancer cells with KRAS or epidermal growth factor receptor (EGFR) mutations. In addition, transbronchial administration of ARL4C ASO‐1316 suppressed orthotopic tumor formation induced by these cancer cells. Thus, ARL4C is involved in the initiation of the premalignant stage and is associated with the stepwise continuum of lung adenocarcinoma. ARL4C ASO‐1316 would be useful for lung adenocarcinoma patients expressing ARL4C regardless of the KRAS or EGFR mutation.
Collapse
Affiliation(s)
- Kenji Kimura
- Department of Molecular Biology and Biochemistry, Graduate School of Medicine, Osaka University, Suita, Japan.,Department of General Thoracic Surgery, Graduate School of Medicine, Osaka University, Suita, Japan
| | - Shinji Matsumoto
- Department of Molecular Biology and Biochemistry, Graduate School of Medicine, Osaka University, Suita, Japan
| | - Takeshi Harada
- Department of Molecular Biology and Biochemistry, Graduate School of Medicine, Osaka University, Suita, Japan
| | - Eiichi Morii
- Department of Pathology, Graduate School of Medicine, Osaka University, Suita, Japan
| | - Izumi Nagatomo
- Department of Respiratory Medicine and Clinical Immunology, Graduate School of Medicine, Osaka University, Suita, Japan
| | - Yasushi Shintani
- Department of General Thoracic Surgery, Graduate School of Medicine, Osaka University, Suita, Japan
| | - Akira Kikuchi
- Department of Molecular Biology and Biochemistry, Graduate School of Medicine, Osaka University, Suita, Japan
| |
Collapse
|
26
|
Chen KJ, Chiang TC, Yu CJ, Lee FJS. Cooperative recruitment of Arl4A and Pak1 to the plasma membrane contributes to sustained Pak1 activation for cell migration. J Cell Sci 2020; 133:jcs233361. [PMID: 31932503 DOI: 10.1242/jcs.233361] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2019] [Accepted: 12/17/2019] [Indexed: 01/27/2023] Open
Abstract
Cell migration requires the coordination of multiple signaling pathways involved in membrane dynamics and cytoskeletal rearrangement. The Arf-like small GTPase Arl4A has been shown to modulate actin cytoskeleton remodeling. However, evidence of the function of Arl4A in cell migration is insufficient. Here, we report that Arl4A acts with the serine/threonine protein kinase Pak1 to modulate cell migration through their cooperative recruitment to the plasma membrane. We first observed that Arl4A and its isoform Arl4D interact with Pak1 and Pak2 and showed that Arl4A recruits Pak1 and Pak2 to the plasma membrane. The fibronectin-induced Pak1 localization at the plasma membrane is reduced in Arl4A-depleted cells. Unexpectedly, we found that Pak1, but not Arl4A-binding-defective Pak1, can recruit a cytoplasmic myristoylation-deficient Arl4A-G2A mutant to the plasma membrane. Furthermore, we found that the Arl4A-Pak1 interaction, which is independent of Rac1 binding to Pak1, is required for Arl4A-induced cell migration. Thus, we infer that there is feedback regulation between Arl4A and Pak1, in which they mutually recruit each other to the plasma membrane for Pak1 activation, thereby modulating cell migration through direct interaction.
Collapse
Affiliation(s)
- Kuan-Jung Chen
- Institute of Molecular Medicine, College of Medicine, National Taiwan University, Taipei 10002, Taiwan
- Department of Medical Research, National Taiwan University Hospital, Taipei 10002, Taiwan
| | - Tsai-Chen Chiang
- Institute of Molecular Medicine, College of Medicine, National Taiwan University, Taipei 10002, Taiwan
- Department of Medical Research, National Taiwan University Hospital, Taipei 10002, Taiwan
| | - Chia-Jung Yu
- Department of Cell and Molecular Biology, College of Medicine, Chang Gung University, Taoyuan 33302, Taiwan
- Department of Thoracic Medicine, Chang Gung Memorial Hospital, Linkou, Taoyuan 33305, Taiwan
| | - Fang-Jen S Lee
- Institute of Molecular Medicine, College of Medicine, National Taiwan University, Taipei 10002, Taiwan
- Department of Medical Research, National Taiwan University Hospital, Taipei 10002, Taiwan
- Center of Precision Medicine, College of Medicine, National Taiwan University, Taipei 10002, Taiwan
| |
Collapse
|
27
|
Sztul E, Chen PW, Casanova JE, Cherfils J, Dacks JB, Lambright DG, Lee FJS, Randazzo PA, Santy LC, Schürmann A, Wilhelmi I, Yohe ME, Kahn RA. ARF GTPases and their GEFs and GAPs: concepts and challenges. Mol Biol Cell 2019; 30:1249-1271. [PMID: 31084567 PMCID: PMC6724607 DOI: 10.1091/mbc.e18-12-0820] [Citation(s) in RCA: 149] [Impact Index Per Article: 29.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2019] [Revised: 02/26/2019] [Accepted: 03/11/2019] [Indexed: 12/12/2022] Open
Abstract
Detailed structural, biochemical, cell biological, and genetic studies of any gene/protein are required to develop models of its actions in cells. Studying a protein family in the aggregate yields additional information, as one can include analyses of their coevolution, acquisition or loss of functionalities, structural pliability, and the emergence of shared or variations in molecular mechanisms. An even richer understanding of cell biology can be achieved through evaluating functionally linked protein families. In this review, we summarize current knowledge of three protein families: the ARF GTPases, the guanine nucleotide exchange factors (ARF GEFs) that activate them, and the GTPase-activating proteins (ARF GAPs) that have the ability to both propagate and terminate signaling. However, despite decades of scrutiny, our understanding of how these essential proteins function in cells remains fragmentary. We believe that the inherent complexity of ARF signaling and its regulation by GEFs and GAPs will require the concerted effort of many laboratories working together, ideally within a consortium to optimally pool information and resources. The collaborative study of these three functionally connected families (≥70 mammalian genes) will yield transformative insights into regulation of cell signaling.
Collapse
Affiliation(s)
- Elizabeth Sztul
- Department of Cell, Developmental and Integrative Biology, University of Alabama at Birmingham, Birmingham, AL 35294
| | - Pei-Wen Chen
- Department of Biology, Williams College, Williamstown, MA 01267
| | - James E. Casanova
- Department of Cell Biology, University of Virginia, Charlottesville, VA 22908
| | - Jacqueline Cherfils
- Laboratoire de Biologie et Pharmacologie Appliquée, CNRS and Ecole Normale Supérieure Paris-Saclay, 94235 Cachan, France
| | - Joel B. Dacks
- Division of Infectious Disease, Department of Medicine, University of Alberta, Edmonton, AB T6G 2H7, Canada
| | - David G. Lambright
- Program in Molecular Medicine and Department of Biochemistry and Molecular Pharmacology, University of Massachusetts Medical School, Amherst, MA 01605
| | - Fang-Jen S. Lee
- Institute of Molecular Medicine, College of Medicine, National Taiwan University, Taipei 10002, Taiwan
| | | | - Lorraine C. Santy
- Department of Biochemistry and Molecular Biology, Pennsylvania State University, University Park, PA 16802
| | - Annette Schürmann
- German Institute of Human Nutrition, 85764 Potsdam-Rehbrücke, Germany
| | - Ilka Wilhelmi
- German Institute of Human Nutrition, 85764 Potsdam-Rehbrücke, Germany
| | - Marielle E. Yohe
- Pediatric Oncology Branch, Center for Cancer Research, National Cancer Institute, Bethesda, MD 20892
| | - Richard A. Kahn
- Department of Biochemistry, Emory University School of Medicine, Atlanta, GA 30322-3050
| |
Collapse
|
28
|
Abstract
Lipids convey both structural and functional properties to eukaryotic membranes. Understanding the basic lipid composition and the dynamics of these important molecules, in the context of cellular membranes, can shed light on signaling, metabolism, trafficking, and even membrane identity. The development of genetically encoded lipid biosensors has allowed for the visualization of specific lipids inside individual, living cells. However, a number of caveats and considerations have emerged with the overexpression of these biosensors. In this Technical Perspective, we provide a current list of available genetically encoded lipid biosensors, together with criteria that determine their veracity. We also provide some suggestions for the optimal utilization of these biosensors when both designing experiments and interpreting results.
Collapse
Affiliation(s)
- Rachel C Wills
- Department of Cell Biology, University of Pittsburgh School of Medicine, Pittsburgh, PA 16261
| | - Brady D Goulden
- Department of Cell Biology, University of Pittsburgh School of Medicine, Pittsburgh, PA 16261
| | - Gerald R V Hammond
- Department of Cell Biology, University of Pittsburgh School of Medicine, Pittsburgh, PA 16261
| |
Collapse
|
29
|
Chen YT, Wang IH, Wang YH, Chiu WY, Hu JH, Chen WH, Lee FJS. Action of Arl1 GTPase and golgin Imh1 in Ypt6-independent retrograde transport from endosomes to the trans-Golgi network. Mol Biol Cell 2019; 30:1008-1019. [PMID: 30726160 PMCID: PMC6589904 DOI: 10.1091/mbc.e18-09-0579] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
The Arf and Rab/Ypt GTPases coordinately regulate membrane traffic and organelle structure by regulating vesicle formation and fusion. Ample evidence has indicated that proteins in these two families may function in parallel or complementarily; however, the manner in which Arf and Rab/Ypt proteins perform interchangeable functions remains unclear. In this study, we report that a Golgi-localized Arf, Arl1, could suppress Ypt6 dysfunction via its effector golgin, Imh1, but not via the lipid flippase Drs2. Ypt6 is critical for the retrograde transport of vesicles from endosomes to the trans-Golgi network (TGN), and its mutation leads to severe protein mislocalization and growth defects. We first overexpress the components of the Arl3-Syt1-Arl1-Imh1 cascade and show that only Arl1 and Imh1 can restore endosome-to-TGN trafficking in ypt6-deleted cells. Interestingly, increased abundance of Arl1 or Imh1 restores localization of the tethering factor Golgi associated retrograde–protein (GARP) complex to the TGN in the absence of Ypt6. We further show that the N-terminal domain of Imh1 is critical for restoring GARP localization and endosome-to-TGN transport in ypt6-deleted cells. Together, our results reveal the mechanism by which Arl1-Imh1 facilitates the recruitment of GARP to the TGN and compensates for the endosome-to-TGN trafficking defects in dysfunctional Ypt6 conditions.
Collapse
Affiliation(s)
- Yan-Ting Chen
- Institute of Molecular Medicine, College of Medicine, National Taiwan University, Taipei 100, Taiwan
| | - I-Hao Wang
- Institute of Molecular Medicine, College of Medicine, National Taiwan University, Taipei 100, Taiwan
| | - Yi-Hsun Wang
- Institute of Molecular Medicine, College of Medicine, National Taiwan University, Taipei 100, Taiwan
| | - Wan-Yun Chiu
- Institute of Molecular Medicine, College of Medicine, National Taiwan University, Taipei 100, Taiwan
| | - Jen-Hao Hu
- Institute of Molecular Medicine, College of Medicine, National Taiwan University, Taipei 100, Taiwan
| | - Wen-Hui Chen
- Institute of Molecular Medicine, College of Medicine, National Taiwan University, Taipei 100, Taiwan
| | - Fang-Jen S Lee
- Institute of Molecular Medicine, College of Medicine, National Taiwan University, Taipei 100, Taiwan.,Department of Medical Research, National Taiwan University Hospital, Taipei 100, Taiwan.,Center of Precision Medicine, College of Medicine, National Taiwan University, Taipei 10002, Taiwan
| |
Collapse
|
30
|
Chiang TS, Lin MC, Tsai MC, Chen CH, Jang LT, Lee FJS. ADP-ribosylation factor-like 4A interacts with Robo1 to promote cell migration by regulating Cdc42 activation. Mol Biol Cell 2019; 30:69-81. [PMID: 30427759 PMCID: PMC6337904 DOI: 10.1091/mbc.e18-01-0001] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2018] [Revised: 10/26/2018] [Accepted: 11/01/2018] [Indexed: 12/11/2022] Open
Abstract
Cell migration is a highly regulated event that is initiated by cell membrane protrusion and actin reorganization. Robo1, a single-pass transmembrane receptor, is crucial for neuronal guidance and cell migration. ADP-ribosylation factor (Arf)-like 4A (Arl4A), an Arf small GTPase, functions in cell morphology, cell migration, and actin cytoskeleton remodeling; however, the molecular mechanisms of Arl4A in cell migration are unclear. Here, we report that the binding of Arl4A to Robo1 modulates cell migration by promoting Cdc42 activation. We found that Arl4A interacts with Robo1 in a GTP-dependent manner and that the Robo1 amino acid residues 1394-1398 are required for this interaction. The Arl4A-Robo1 interaction is essential for Arl4A-induced cell migration and Cdc42 activation but not for the plasma membrane localization of Robo1. In addition, we show that the binding of Arl4A to Robo1 decreases the association of Robo1 with the Cdc42 GTPase-activating protein srGAP1. Furthermore, Slit2/Robo1 binding down-regulates the Arl4A-Robo1 interaction in vivo, thus attenuating Cdc42-mediated cell migration. Therefore, our study reveals a novel mechanism by which Arl4A participates in Slit2/Robo1 signaling to modulate cell motility by regulating Cdc42 activity.
Collapse
Affiliation(s)
- Tsai-Shin Chiang
- Institute of Molecular Medicine, National Taiwan University, Taipei 10002, Taiwan
| | - Ming-Chieh Lin
- Institute of Molecular Medicine, National Taiwan University, Taipei 10002, Taiwan
- Center of Precision Medicine, College of Medicine, National Taiwan University, Taipei 10002, Taiwan
| | - Meng-Chen Tsai
- Institute of Molecular Medicine, National Taiwan University, Taipei 10002, Taiwan
| | - Chieh-Hsin Chen
- Institute of Molecular Medicine, National Taiwan University, Taipei 10002, Taiwan
| | - Li-Ting Jang
- Institute of Molecular Medicine, National Taiwan University, Taipei 10002, Taiwan
| | - Fang-Jen S. Lee
- Institute of Molecular Medicine, National Taiwan University, Taipei 10002, Taiwan
- Center of Precision Medicine, College of Medicine, National Taiwan University, Taipei 10002, Taiwan
- Department of Medical Research, National Taiwan University Hospital, Taipei 10002, Taiwan
| |
Collapse
|
31
|
Somerville TDD, Xu Y, Miyabayashi K, Tiriac H, Cleary CR, Maia-Silva D, Milazzo JP, Tuveson DA, Vakoc CR. TP63-Mediated Enhancer Reprogramming Drives the Squamous Subtype of Pancreatic Ductal Adenocarcinoma. Cell Rep 2018; 25:1741-1755.e7. [PMID: 30428345 PMCID: PMC6296757 DOI: 10.1016/j.celrep.2018.10.051] [Citation(s) in RCA: 128] [Impact Index Per Article: 21.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2018] [Revised: 09/06/2018] [Accepted: 10/12/2018] [Indexed: 12/14/2022] Open
Abstract
The aberrant expression of squamous lineage markers in pancreatic ductal adenocarcinoma (PDA) has been correlated with poor clinical outcomes. However, the functional role of this putative transdifferentiation event in PDA pathogenesis remains unclear. Here, we show that expression of the transcription factor TP63 (ΔNp63) is sufficient to install and sustain the enhancer landscape and transcriptional signature of the squamous lineage in human PDA cells. We also demonstrate that TP63-driven enhancer reprogramming promotes aggressive tumor phenotypes, including enhanced cell motility and invasion, and an accelerated growth of primary PDA tumors and metastases in vivo. This process ultimately leads to a powerful addiction of squamous PDA cells to continuous TP63 expression. Our study demonstrates the functional significance of squamous transdifferentiation in PDA and reveals TP63-based reprogramming as an experimental tool for investigating mechanisms and vulnerabilities linked to this aberrant cell fate transition.
Collapse
Affiliation(s)
| | - Yali Xu
- Cold Spring Harbor Laboratory, Cold Spring Harbor, NY 11724, USA
| | - Koji Miyabayashi
- Cold Spring Harbor Laboratory, Cold Spring Harbor, NY 11724, USA; Lustgarten Foundation Pancreatic Cancer Research Laboratory, Cold Spring Harbor, NY 11724, USA
| | - Hervé Tiriac
- Cold Spring Harbor Laboratory, Cold Spring Harbor, NY 11724, USA; Lustgarten Foundation Pancreatic Cancer Research Laboratory, Cold Spring Harbor, NY 11724, USA
| | - Cristian R Cleary
- Cold Spring Harbor Laboratory, Cold Spring Harbor, NY 11724, USA; Graduate Program in Genetics, Stony Brook University, Stony Brook, NY 11794, USA
| | - Diogo Maia-Silva
- Cold Spring Harbor Laboratory, Cold Spring Harbor, NY 11724, USA; Watson School of Biological Sciences, Cold Spring Harbor Laboratory, Cold Spring Harbor, NY 11724, USA
| | - Joseph P Milazzo
- Cold Spring Harbor Laboratory, Cold Spring Harbor, NY 11724, USA
| | - David A Tuveson
- Cold Spring Harbor Laboratory, Cold Spring Harbor, NY 11724, USA; Lustgarten Foundation Pancreatic Cancer Research Laboratory, Cold Spring Harbor, NY 11724, USA
| | | |
Collapse
|
32
|
The PDL1-inducible GTPase Arl4d controls T effector function by limiting IL-2 production. Sci Rep 2018; 8:16123. [PMID: 30382149 PMCID: PMC6208435 DOI: 10.1038/s41598-018-34522-4] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2018] [Accepted: 10/08/2018] [Indexed: 11/20/2022] Open
Abstract
Interleukin-2 (IL-2) is a key regulator of adaptive immune responses but its regulation is incompletely understood. We previously found that PDL1-dependent signals were pivotal for liver sinusoidal endothelial cell-mediated priming of CD8 T cells, which have a strongly reduced capacity to produce IL-2. Here, we show that the expression of the ARF-like GTPase Arl4d is PD-L1-dependently induced in such LSEC-primed T cells, and is associated with reduced IL-2 secretion and Akt phosphorylation. Conversely, Arl4d-deficient T cells overproduced IL-2 upon stimulation. Arl4d-deficiency in CD8 T cells also enhanced their expansion and effector function during viral infection in vivo. Consistent with their increased IL-2 production, Arl4d-deficient T cells showed enhanced development into KLRG1+CD127− short-lived effector cells (SLEC), which is dependent on IL-2 availability. Thus, our data reveal a PD-L1-dependent regulatory circuitry that involves the induction of Arl4d for limiting IL-2 production in T cells.
Collapse
|
33
|
Ito A, Fukaya M, Saegusa S, Kobayashi E, Sugawara T, Hara Y, Yamauchi J, Okamoto H, Sakagami H. Pallidin is a novel interacting protein for cytohesin-2 and regulates the early endosomal pathway and dendritic formation in neurons. J Neurochem 2018; 147:153-177. [PMID: 30151872 DOI: 10.1111/jnc.14579] [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] [Received: 03/15/2018] [Revised: 07/25/2018] [Accepted: 08/21/2018] [Indexed: 12/29/2022]
Abstract
Cytohesin-2 is a member of the guanine nucleotide exchange factors for ADP ribosylation factor 1 (Arf1) and Arf6, which are small GTPases that regulate membrane traffic and actin dynamics. In this study, we first demonstrated that cytohesin-2 localized to the plasma membrane and vesicles in various subcellular compartment in hippocampal neurons by immunoelectron microscopy. Next, to understand the molecular network of cytohesin-2 in neurons, we conducted yeast two-hybrid screening of brain cDNA libraries using cytohesin-2 as bait and isolated pallidin, a component of the biogenesis of lysosome-related organelles complex 1 (BLOC-1) involved in endosomal trafficking. Pallidin interacted specifically with cytohesin-2 among cytohesin family members. Glutathione S-transferase pull-down and immunoprecipitation assays further confirmed the formation of a protein complex between cytohesin-2 and pallidin. Immunofluorescence demonstrated that cytohesin-2 and pallidin partially colocalized in various subsets of endosomes immunopositive for EEA1, syntaxin 12, and LAMP2 in hippocampal neurons. Knockdown of pallidin or cytohesin-2 reduced cytoplasmic EEA1-positive early endosomes. Furthermore, knockdown of pallidin increased the total dendritic length of cultured hippocampal neurons, which was rescued by co-expression of wild-type pallidin but not a mutant lacking the ability to interact with cytohesin-2. In contrast, knockdown of cytohesin-2 had the opposite effect on total dendritic length. The present results suggested that the interaction between pallidin and cytohesin-2 may participate in various neuronal functions such as endosomal trafficking and dendritic formation in hippocampal neurons. Cover Image for this issue: doi: 10.1111/jnc.14197.
Collapse
Affiliation(s)
- Akiko Ito
- Department of Anatomy, Kitasato University School of Medicine, Sagamihara, Kanagawa, Japan.,Department of Anesthesiology, Kitasato University School of Medicine, Sagamihara, Kanagawa, Japan
| | - Masahiro Fukaya
- Department of Anatomy, Kitasato University School of Medicine, Sagamihara, Kanagawa, Japan
| | - Shintaro Saegusa
- Department of Anatomy, Kitasato University School of Medicine, Sagamihara, Kanagawa, Japan
| | - Emi Kobayashi
- Department of Anatomy, Kitasato University School of Medicine, Sagamihara, Kanagawa, Japan
| | - Takeyuki Sugawara
- Department of Anatomy, Kitasato University School of Medicine, Sagamihara, Kanagawa, Japan
| | - Yoshinobu Hara
- Department of Anatomy, Kitasato University School of Medicine, Sagamihara, Kanagawa, Japan
| | - Junji Yamauchi
- Laboratory of Molecular Neuroscience and Neurology, School of Life Sciences, Tokyo University of Pharmacy and Life Sciences, Hachioji, Tokyo, Japan
| | - Hirotsugu Okamoto
- Department of Anesthesiology, Kitasato University School of Medicine, Sagamihara, Kanagawa, Japan
| | - Hiroyuki Sakagami
- Department of Anatomy, Kitasato University School of Medicine, Sagamihara, Kanagawa, Japan
| |
Collapse
|
34
|
Juszczak GR, Stankiewicz AM. Glucocorticoids, genes and brain function. Prog Neuropsychopharmacol Biol Psychiatry 2018; 82:136-168. [PMID: 29180230 DOI: 10.1016/j.pnpbp.2017.11.020] [Citation(s) in RCA: 82] [Impact Index Per Article: 13.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/08/2017] [Revised: 10/18/2017] [Accepted: 11/23/2017] [Indexed: 01/02/2023]
Abstract
The identification of key genes in transcriptomic data constitutes a huge challenge. Our review of microarray reports revealed 88 genes whose transcription is consistently regulated by glucocorticoids (GCs), such as cortisol, corticosterone and dexamethasone, in the brain. Replicable transcriptomic data were combined with biochemical and physiological data to create an integrated view of the effects induced by GCs. The most frequently reported genes were Errfi1 and Ddit4. Their up-regulation was associated with the altered transcription of genes regulating growth factor and mTORC1 signaling (Gab1, Tsc22d3, Dusp1, Ndrg2, Ppp5c and Sesn1) and progression of the cell cycle (Ccnd1, Cdkn1a and Cables1). The GC-induced reprogramming of cell function involves changes in the mRNA level of genes responsible for the regulation of transcription (Klf9, Bcl6, Klf15, Tle3, Cxxc5, Litaf, Tle4, Jun, Sox4, Sox2, Sox9, Irf1, Sall2, Nfkbia and Id1) and the selective degradation of mRNA (Tob2). Other genes are involved in the regulation of metabolism (Gpd1, Aldoc and Pdk4), actin cytoskeleton (Myh2, Nedd9, Mical2, Rhou, Arl4d, Osbpl3, Arhgef3, Sdc4, Rdx, Wipf3, Chst1 and Hepacam), autophagy (Eva1a and Plekhf1), vesicular transport (Rhob, Ehd3, Vps37b and Scamp2), gap junctions (Gjb6), immune response (Tiparp, Mertk, Lyve1 and Il6r), signaling mediated by thyroid hormones (Thra and Sult1a1), calcium (Calm2), adrenaline/noradrenaline (Adcy9 and Adra1d), neuropeptide Y (Npy1r) and histamine (Hdc). GCs also affected genes involved in the synthesis of polyamines (Azin1) and taurine (Cdo1). The actions of GCs are restrained by feedback mechanisms depending on the transcription of Sgk1, Fkbp5 and Nr3c1. A side effect induced by GCs is increased production of reactive oxygen species. Available data show that the brain's response to GCs is part of an emergency mode characterized by inactivation of non-core activities, restrained inflammation, restriction of investments (growth), improved efficiency of energy production and the removal of unnecessary or malfunctioning cellular components to conserve energy and maintain nutrient supply during the stress response.
Collapse
Affiliation(s)
- Grzegorz R Juszczak
- Department of Animal Behavior, Institute of Genetics and Animal Breeding, Jastrzebiec, ul. Postepu 36A, 05-552 Magdalenka, Poland.
| | - Adrian M Stankiewicz
- Department of Molecular Biology, Institute of Genetics and Animal Breeding, Jastrzebiec, ul. Postepu 36A, 05-552 Magdalenka, Poland
| |
Collapse
|
35
|
Chiang TS, Wu HF, Lee FJS. ADP-ribosylation factor-like 4C binding to filamin-A modulates filopodium formation and cell migration. Mol Biol Cell 2017; 28:3013-3028. [PMID: 28855378 PMCID: PMC5662259 DOI: 10.1091/mbc.e17-01-0059] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2017] [Revised: 08/17/2017] [Accepted: 08/25/2017] [Indexed: 11/30/2022] Open
Abstract
Filamin-A plays a key role in tumorigenesis as well as the metastatic progression of prostate cancer, ovarian cancer, and gastric carcinoma. In this study, we identified filamin-A as a novel effector of Arl4C and showed that binding between Arl4C and FLNa modulates the formation of filopodia and cell migration by promoting activation of Cdc42. Changes in cell morphology and the physical forces that occur during migration are generated by a dynamic filamentous actin cytoskeleton. The ADP-ribosylation factor–like 4C (Arl4C) small GTPase acts as a molecular switch to regulate morphological changes and cell migration, although the mechanism by which this occurs remains unclear. Here we report that Arl4C functions with the actin regulator filamin-A (FLNa) to modulate filopodium formation and cell migration. We found that Arl4C interacted with FLNa in a GTP-dependent manner and that FLNa IgG repeat 22 is both required and sufficient for this interaction. We also show that interaction between FLNa and Arl4C is essential for Arl4C-induced filopodium formation and increases the association of FLNa with Cdc42-GEF FGD6, promoting cell division cycle 42 (Cdc42) GTPase activation. Thus our study revealed a novel mechanism, whereby filopodium formation and cell migration are regulated through the Arl4C-FLNa–mediated activation of Cdc42.
Collapse
Affiliation(s)
- Tsai-Shin Chiang
- Institute of Molecular Medicine, College of Medicine, National Taiwan University, 100 Taipei, Taiwan
| | - Hsu-Feng Wu
- Institute of Molecular Medicine, College of Medicine, National Taiwan University, 100 Taipei, Taiwan
| | - Fang-Jen S Lee
- Institute of Molecular Medicine, College of Medicine, National Taiwan University, 100 Taipei, Taiwan .,Department of Medical Research, National Taiwan University Hospital, 100 Taipei, Taiwan
| |
Collapse
|
36
|
Matsumoto S, Fujii S, Kikuchi A. Arl4c is a key regulator of tubulogenesis and tumourigenesis as a target gene of Wnt-β-catenin and growth factor-Ras signalling. J Biochem 2016; 161:27-35. [PMID: 28053143 DOI: 10.1093/jb/mvw069] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2016] [Accepted: 09/13/2016] [Indexed: 12/19/2022] Open
Abstract
Epithelial tubular morphogenesis (tubulogenesis) is a fundamental morphogenetic process of many epithelial organs. In this developmental process, epithelial cells migrate, proliferate, polarize and differentiate towards surrounding mesenchymal tissue to form tubule structures. Although epithelial tissue structures are basically stable in the postnatal period, epithelial cells regain highly proliferative and invasive potentials within mesenchymal tissue during tumour formation (tumourigenesis). Therefore, there must be a common molecular basis orchestrating the cellular behaviours involved in both tubulogenesis and tumourigenesis. ADP-ribosylation factor (Arf)-like protein 4c (Arl4c), which belongs to the small GTP-binding protein family, is expressed by the simultaneous activation of Wnt-β-catenin and growth factor-Ras-mitogen-activated protein kinase signalling, was identified as an essential regulator of tubulogenesis. Arl4c expression was also involved in the tumour formation of colorectal and lung cancers. In this review, we focus on Arl4c as a novel Wnt signal target molecule that links epithelial tubulogenesis to tumourigenesis.
Collapse
Affiliation(s)
- Shinji Matsumoto
- Department of Molecular Biology and Biochemistry, Graduate School of Medicine, Osaka University, 2-2 Yamadaoka, Suita, Osaka 565-0871, Japan
| | - Shinsuke Fujii
- Department of Molecular Biology and Biochemistry, Graduate School of Medicine, Osaka University, 2-2 Yamadaoka, Suita, Osaka 565-0871, Japan.,Laboratory of Oral Pathology, Division of Maxillofacial Diagnostic and Surgical Sciences, Faculty of Dental Science, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka 812-8582, Japan
| | - Akira Kikuchi
- Department of Molecular Biology and Biochemistry, Graduate School of Medicine, Osaka University, 2-2 Yamadaoka, Suita, Osaka 565-0871, Japan
| |
Collapse
|
37
|
Abstract
Members of the ADP-ribosylation factor (Arf) family of small GTP-binding (G) proteins regulate several aspects of membrane trafficking, such as vesicle budding, tethering and cytoskeleton organization. Arf family members, including Arf-like (Arl) proteins have been implicated in several essential cellular functions, like cell spreading and migration. These functions are used by cancer cells to disseminate and invade the tissues surrounding the primary tumor, leading to the formation of metastases. Indeed, Arf and Arl proteins, as well as their guanine nucleotide exchange factors (GEFs) and GTPase-activating proteins (GAPs) have been found to be abnormally expressed in different cancer cell types and human cancers. Here, we review the current evidence supporting the involvement of Arf family proteins and their GEFs and GAPs in cancer progression, focusing on 3 different mechanisms: cell-cell adhesion, integrin internalization and recycling, and actin cytoskeleton remodeling.
Collapse
Affiliation(s)
- Cristina Casalou
- a CEDOC, NOVA Medical School - Faculdade de Ciências Médicas, Universidade NOVA de Lisboa , Lisbon , Portugal
| | - Alexandra Faustino
- a CEDOC, NOVA Medical School - Faculdade de Ciências Médicas, Universidade NOVA de Lisboa , Lisbon , Portugal.,b ProRegeM PhD Program, NOVA Medical School - Faculdade de Ciências Médicas, Universidade NOVA de Lisboa , Lisbon , Portugal
| | - Duarte C Barral
- a CEDOC, NOVA Medical School - Faculdade de Ciências Médicas, Universidade NOVA de Lisboa , Lisbon , Portugal
| |
Collapse
|
38
|
Hammond GRV, Balla T. Polyphosphoinositide binding domains: Key to inositol lipid biology. Biochim Biophys Acta Mol Cell Biol Lipids 2015; 1851:746-58. [PMID: 25732852 DOI: 10.1016/j.bbalip.2015.02.013] [Citation(s) in RCA: 168] [Impact Index Per Article: 18.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2014] [Revised: 01/29/2015] [Accepted: 02/17/2015] [Indexed: 01/01/2023]
Abstract
Polyphosphoinositides (PPIn) are an important family of phospholipids located on the cytoplasmic leaflet of eukaryotic cell membranes. Collectively, they are critical for the regulation of many aspects of membrane homeostasis and signaling, with notable relevance to human physiology and disease. This regulation is achieved through the selective interaction of these lipids with hundreds of cellular proteins, and thus the capability to study these localized interactions is crucial to understanding their functions. In this review, we discuss current knowledge of the principle types of PPIn-protein interactions, focusing on specific lipid-binding domains. We then discuss how these domains have been re-tasked by biologists as molecular probes for these lipids in living cells. Finally, we describe how the knowledge gained with these probes, when combined with other techniques, has led to the current view of the lipids' localization and function in eukaryotes, focusing mainly on animal cells. This article is part of a Special Issue entitled Phosphoinositides.
Collapse
Affiliation(s)
- Gerald R V Hammond
- Department of Cell Biology, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA.
| | - Tamas Balla
- Section on Molecular Signal Transduction, Eunice Shriver Kennedy National Institute for Child Health and Human Development, National Institutes of Health, Bethesda, MD, USA.
| |
Collapse
|
39
|
Liu J, Lee DM, Yu CG, Angers S, Harris TJC. Stepping stone: a cytohesin adaptor for membrane cytoskeleton restraint in the syncytial Drosophila embryo. Mol Biol Cell 2014; 26:711-25. [PMID: 25540427 PMCID: PMC4325841 DOI: 10.1091/mbc.e14-11-1554] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
Abstract
Cytohesin Arf-GEFs are conserved plasma membrane regulators. The sole Drosophila cytohesin, Steppke, restrains Rho1-dependent membrane cytoskeleton activity at the base of plasma membrane furrows of the syncytial embryo. By mass spectrometry, we identified a single major Steppke-interacting protein from syncytial embryos, which we named Stepping stone (Sstn). By sequence, Sstn seems to be a divergent homologue of the mammalian cytohesin adaptor FRMD4A. Our experiments supported this relationship. Specifically, heterophilic coiled-coil interactions linked Sstn and Steppke in vivo and in vitro, whereas a separate C-terminal region was required for Sstn localization to furrows. Sstn mutant and RNAi embryos displayed abnormal, Rho1-dependent membrane cytoskeleton expansion from the base of pseudocleavage and cellularization furrows, closely mimicking Steppke loss-of-function embryos. Elevating Sstn furrow levels had no effect on the steppke phenotype, but elevating Steppke furrow levels reversed the sstn phenotype, suggesting that Steppke acts downstream of Sstn and that additional mechanisms can recruit Steppke to furrows. Finally, the coiled-coil domain of Steppke was required for Sstn binding and in addition homodimerization, and its removal disrupted Steppke furrow localization and activity in vivo. Overall we propose that Sstn acts as a cytohesin adaptor that promotes Steppke activity for localized membrane cytoskeleton restraint in the syncytial Drosophila embryo.
Collapse
Affiliation(s)
- Jiangshu Liu
- Department of Cell and Systems Biology, University of Toronto, Toronto, ON M5S 3G5, Canada
| | - Donghoon M Lee
- Department of Cell and Systems Biology, University of Toronto, Toronto, ON M5S 3G5, Canada
| | - Cao Guo Yu
- Department of Cell and Systems Biology, University of Toronto, Toronto, ON M5S 3G5, Canada
| | - Stephane Angers
- Department of Pharmaceutical Sciences, Leslie Dan Faculty of Pharmacy, University of Toronto, Toronto, ON M5S 3G5, Canada Department of Biochemistry, University of Toronto, Toronto, ON M5S 3G5, Canada
| | - Tony J C Harris
- Department of Cell and Systems Biology, University of Toronto, Toronto, ON M5S 3G5, Canada
| |
Collapse
|
40
|
Caveolin-1 regulates genomic action of the glucocorticoid receptor in neural stem cells. Mol Cell Biol 2014; 34:2611-23. [PMID: 24777604 DOI: 10.1128/mcb.01121-13] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
While glucocorticoids (GCs) are used clinically to treat many conditions, their neonatal and prenatal usage is increasingly controversial due to reports of delayed adverse outcomes, especially their effects on brain development. Such alterations may reflect the impact of GCs on neural progenitor/stem cell (NPSC) function. We previously demonstrated that the lipid raft protein caveolin-1 (Cav-1) was required for rapid GC signaling in embryonic mouse NPSCs operating through plasma membrane-bound glucocorticoid receptors (GRs). We show here that genomic GR signaling in NPSCs requires Cav-1. Loss of Cav-1 impacts the transcriptional response of many GR target genes (e.g., the serum- and glucocorticoid-regulated kinase 1 gene) that are likely to mediate the antiproliferative effects of GCs. Microarray analysis of wild-type C57 or Cav-1-deficient NPSCs identified approximately 100 genes that are differentially regulated by GC treatment. These changes in hormone responsiveness in Cav-1 knockout NPSCs are associated with the loss of GC-regulated phosphorylation of GR at serine 211 but not at serine 226. Chromatin recruitment of total GR to regulatory regions of target genes such as Fkbp-5, RhoJ, and Sgk-1, as well as p211-GR recruitment to Sgk-1, are compromised in Cav-1 knockout NPSCs. Cav-1 is therefore a multifunctional regulator of GR in NPSCs influencing both rapid and genomic action of the receptor to impact cell proliferation.
Collapse
|
41
|
Fujii S, Matsumoto S, Nojima S, Morii E, Kikuchi A. Arl4c expression in colorectal and lung cancers promotes tumorigenesis and may represent a novel therapeutic target. Oncogene 2014; 34:4834-44. [PMID: 25486429 DOI: 10.1038/onc.2014.402] [Citation(s) in RCA: 60] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2014] [Revised: 10/29/2014] [Accepted: 10/30/2014] [Indexed: 12/27/2022]
Abstract
We recently demonstrated that expression of ADP-ribosylation factor (ARF)-like 4c (Arl4c) induced by a combination of Wnt/β-catenin and epidermal growth factor/Ras signaling in normal epithelial cells grown in three-dimensional culture promotes cellular migration and proliferation, resulting in formation of tube-like structures, suggesting the involvement of Arl4c in epithelial morphogenesis. It is conceivable that there could be a common mechanism between epithelial morphogenesis and carcinogenesis. Therefore the current study was conducted to investigate whether Arl4c might be involved in tumorigenesis. Immunohistochemical analyses of tissue specimens obtained from colorectal and lung cancer patients revealed that Arl4c was not observed in non-tumor regions but was strongly expressed at high frequencies in tumor lesions. Inhibition of Wnt/β-catenin or Ras/mitogen-activated protein kinase signaling reduced Arl4c mRNA levels in HCT116 colorectal cancer cells and A549 lung cancer cells. Knockdown of Arl4c inhibited Rac activity and also prevented nuclear localization of yes-associated protein (YAP)/transcriptional co-activator with PDZ-binding motif (TAZ) in these cancer cells. Arl4c-depleted cancer cells consistently showed decreased migration, invasion and proliferation capabilities both in vitro and in vivo. Furthermore, direct injection of Arl4c small interfering RNA (siRNA) into HCT116 cell-derived tumors (in vivo treatment with siRNA) inhibited tumor growth in immunodeficient mice. These results suggest that Arl4c is involved in tumorigenesis and might represent a novel therapeutic target for suppressing proliferation and invasion of colorectal and lung cancer cells.
Collapse
Affiliation(s)
- S Fujii
- Department of Molecular Biology and Biochemistry, Graduate School of Medicine, Osaka University, Suita, Japan.,Interdisciplinary Program for Biomedical Sciences (IPBS), Institute for Academic Initiatives, Osaka University, Suita, Japan
| | - S Matsumoto
- Department of Molecular Biology and Biochemistry, Graduate School of Medicine, Osaka University, Suita, Japan
| | - S Nojima
- Department of Pathology, Graduate School of Medicine, Osaka University, Suita, Japan
| | - E Morii
- Department of Pathology, Graduate School of Medicine, Osaka University, Suita, Japan
| | - A Kikuchi
- Department of Molecular Biology and Biochemistry, Graduate School of Medicine, Osaka University, Suita, Japan
| |
Collapse
|
42
|
Torii T, Miyamoto Y, Tago K, Sango K, Nakamura K, Sanbe A, Tanoue A, Yamauchi J. Arf6 guanine nucleotide exchange factor cytohesin-2 binds to CCDC120 and is transported along neurites to mediate neurite growth. J Biol Chem 2014; 289:33887-903. [PMID: 25326380 DOI: 10.1074/jbc.m114.575787] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The mechanism of neurite growth is complicated, involving continuous cytoskeletal rearrangement and vesicular trafficking. Cytohesin-2 is a guanine nucleotide exchange factor for Arf6, an Arf family molecular switch protein, controlling cell morphological changes such as neuritogenesis. Here, we show that cytohesin-2 binds to a protein with a previously unknown function, CCDC120, which contains three coiled-coil domains, and is transported along neurites in differentiating N1E-115 cells. Transfection of the small interfering RNA (siRNA) specific for CCDC120 into cells inhibits neurite growth and Arf6 activation. When neurites start to extend, vesicles containing CCDC120 and cytohesin-2 are transported in an anterograde manner rather than a retrograde one. As neurites continue extension, anterograde vesicle transport decreases. CCDC120 knockdown inhibits cytohesin-2 localization into vesicles containing CCDC120 and diffuses cytohesin-2 in cytoplasmic regions, illustrating that CCDC120 determines cytohesin-2 localization in growing neurites. Reintroduction of the wild type CCDC120 construct into cells transfected with CCDC120 siRNA reverses blunted neurite growth and Arf6 activity, whereas the cytohesin-2-binding CC1 region-deficient CCDC120 construct does not. Thus, cytohesin-2 is transported along neurites by vesicles containing CCDC120, and it mediates neurite growth. These results suggest a mechanism by which guanine nucleotide exchange factor for Arf6 is transported to mediate neurite growth.
Collapse
Affiliation(s)
- Tomohiro Torii
- From the Department of Pharmacology, National Research Institute for Child Health and Development, Setagaya, Tokyo 157-8535,
| | - Yuki Miyamoto
- From the Department of Pharmacology, National Research Institute for Child Health and Development, Setagaya, Tokyo 157-8535
| | - Kenji Tago
- the Graduate School of Medicine, Jichi Medical University, Shimotsuke, Tochigi 329-0498
| | - Kazunori Sango
- the Amyotrophic Lateral Sclerosis/Neuropathy Project, Tokyo Metropolitan Institute of Medical Science, Setagaya, Tokyo 156-8506
| | - Kazuaki Nakamura
- From the Department of Pharmacology, National Research Institute for Child Health and Development, Setagaya, Tokyo 157-8535
| | - Atsushi Sanbe
- the School of Pharmacy, Iwate Medical University, Morioka, Iwate 020-0023, and
| | - Akito Tanoue
- From the Department of Pharmacology, National Research Institute for Child Health and Development, Setagaya, Tokyo 157-8535
| | - Junji Yamauchi
- From the Department of Pharmacology, National Research Institute for Child Health and Development, Setagaya, Tokyo 157-8535, the Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, Bunkyo, Tokyo 113-8510, Japan
| |
Collapse
|
43
|
Abstract
The Arf small G proteins regulate protein and lipid trafficking in eukaryotic cells through a regulated cycle of GTP binding and hydrolysis. In their GTP-bound form, Arf proteins recruit a specific set of protein effectors to the membrane surface. These effectors function in vesicle formation and tethering, non-vesicular lipid transport and cytoskeletal regulation. Beyond fundamental membrane trafficking roles, Arf proteins also regulate mitosis, plasma membrane signaling, cilary trafficking and lipid droplet function. Tight spatial and temporal regulation of the relatively small number of Arf proteins is achieved by their guanine nucleotide-exchange factors (GEFs) and GTPase-activating proteins (GAPs), which catalyze GTP binding and hydrolysis, respectively. A unifying function of Arf proteins, performed in conjunction with their regulators and effectors, is sensing, modulating and transporting the lipids that make up cellular membranes. In this Cell Science at a Glance article and the accompanying poster, we discuss the unique features of Arf small G proteins, their functions in vesicular and lipid trafficking in cells, and how these functions are modulated by their regulators, the GEFs and GAPs. We also discuss how these Arf functions are subverted by human pathogens and disease states.
Collapse
Affiliation(s)
- Catherine L Jackson
- Membrane Dynamics and Intracellular Trafficking, Institut Jacques Monod, CNRS, UMR 7592, Université Paris Diderot, Sorbonne Paris Cité, F-75013 Paris, France
| | - Samuel Bouvet
- Membrane Dynamics and Intracellular Trafficking, Institut Jacques Monod, CNRS, UMR 7592, Université Paris Diderot, Sorbonne Paris Cité, F-75013 Paris, France
| |
Collapse
|
44
|
Asymmetric neuroblast divisions producing apoptotic cells require the cytohesin GRP-1 in Caenorhabditis elegans. Genetics 2014; 198:229-47. [PMID: 25053664 DOI: 10.1534/genetics.114.167189] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
Cytohesins are Arf guanine nucleotide exchange factors (GEFs) that regulate membrane trafficking and actin cytoskeletal dynamics. We report here that GRP-1, the sole Caenorhabditis elegans cytohesin, controls the asymmetric divisions of certain neuroblasts that divide to produce a larger neuronal precursor or neuron and a smaller cell fated to die. In the Q neuroblast lineage, loss of GRP-1 led to the production of daughter cells that are more similar in size and to the transformation of the normally apoptotic daughter into its sister, resulting in the production of extra neurons. Genetic interactions suggest that GRP-1 functions with the previously described Arf GAP CNT-2 and two other Arf GEFs, EFA-6 and BRIS-1, to regulate the activity of Arf GTPases. In agreement with this model, we show that GRP-1's GEF activity, mediated by its SEC7 domain, is necessary for the posterior Q cell (Q.p) neuroblast division and that both GRP-1 and CNT-2 function in the Q.posterior Q daughter cell (Q.p) to promote its asymmetry. Although functional GFP-tagged GRP-1 proteins localized to the nucleus, the extra cell defects were rescued by targeting the Arf GEF activity of GRP-1 to the plasma membrane, suggesting that GRP-1 acts at the plasma membrane. The detection of endogenous GRP-1 protein at cytokinesis remnants, or midbodies, is consistent with GRP-1 functioning at the plasma membrane and perhaps at the cytokinetic furrow to promote the asymmetry of the divisions that require its function.
Collapse
|
45
|
Wittinghofer A. Arf Proteins and Their Regulators: At the Interface Between Membrane Lipids and the Protein Trafficking Machinery. RAS SUPERFAMILY SMALL G PROTEINS: BIOLOGY AND MECHANISMS 2 2014. [PMCID: PMC7123483 DOI: 10.1007/978-3-319-07761-1_8] [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] [Indexed: 12/02/2022]
Abstract
The Arf small GTP-binding (G) proteins regulate membrane traffic and organelle structure in eukaryotic cells through a regulated cycle of GTP binding and hydrolysis. The first function identified for Arf proteins was recruitment of cytosolic coat complexes to membranes to mediate vesicle formation. However, subsequent studies have uncovered additional functions, including roles in plasma membrane signalling pathways, cytoskeleton regulation, lipid droplet function, and non-vesicular lipid transport. In contrast to other families of G proteins, there are only a few Arf proteins in each organism, yet they function specifically at many different cellular locations. Part of this specificity is achieved by formation of complexes with their guanine nucleotide-exchange factors (GEFs) and GTPase activating proteins (GAPs) that catalyse GTP binding and hydrolysis, respectively. Because these regulators outnumber their Arf substrates by at least 3-to-1, an important aspect of understanding Arf function is elucidating the mechanisms by which a single Arf protein is incorporated into different GEF, GAP, and effector complexes. New insights into these mechanisms have come from recent studies showing GEF–effector interactions, Arf activation cascades, and positive feedback loops. A unifying theme in the function of Arf proteins, carried out in conjunction with their regulators and effectors, is sensing and modulating the properties of the lipids that make up cellular membranes.
Collapse
Affiliation(s)
- Alfred Wittinghofer
- Max-Planck-Institute of Molecular Physiology, Dortmund, Nordrhein-Westfalen Germany
| |
Collapse
|
46
|
Kawaguchi K, Saito K, Asami H, Ohta Y. ADP ribosylation factor 6 (Arf6) acts through FilGAP protein to down-regulate Rac protein and regulates plasma membrane blebbing. J Biol Chem 2014; 289:9675-82. [PMID: 24526684 DOI: 10.1074/jbc.m113.546051] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The small GTP-binding protein Arf6 reorganizes the actin cytoskeleton through the regulation of Rac activity. We identified FilGAP, a Rac-specific Rho GTPase-activating protein that is recruited to plasma membranes by binding to activated Arf6. FilGAP binds to Arf6 through its pleckstrin homology domain. Activated Arf6 stimulated RacGAP activity of FilGAP, and knockdown of endogenous Arf6 by siRNA suppresses FilGAP-mediated bleb formation. Mutant FilGAP lacking phosphatidylinositol 3,4,5-trisphosphate (PIP3) binding (FilGAP R39C) binds to activated Arf6 and induces bleb formation. Moreover, bleb formation induced by wild-type FilGAP occurs in the presence of phosphatidylinositol 3-kinase inhibitors, suggesting a PIP3-independent interaction between FilGAP and Arf6. We propose that FilGAP may function as a mediator of the regulation of Rac by Arf6.
Collapse
Affiliation(s)
- Kaori Kawaguchi
- From the Division of Cell Biology, Department of Biosciences, School of Science, Kitasato University, 1-15-1 Kitasato, Sagamihara, Minami-ku, Kanagawa 252-0373, Japan
| | | | | | | |
Collapse
|
47
|
Abstract
The ARF-like (ARL) proteins, within the ARF family, are a collection of functionally diverse GTPases that share extensive (>40 %) identity with the ARFs and each other and are assumed to share basic mechanisms of regulation and a very incompletely documented degree of overlapping regulators. At least four ARLs were already present in the last eukaryotic common ancestor, along with one ARF, and these have been expanded to >20 members in mammals. We know little about the majority of these proteins so our review will focus on those about which the most is known, including ARL1, ARL2, ARL3, ARL4s, ARL6, ARL13s, and ARFRP1. From this fragmentary information we extract some generalizations and conclusions regarding the sources and extent of specificity and functions of the ARLs.
Collapse
Affiliation(s)
- Alfred Wittinghofer
- Max-Planck-Institute of Molecular Physiology, Dortmund, Nordrhein-Westfalen Germany
| |
Collapse
|
48
|
Hiester KG, Santy LC. The cytohesin coiled-coil domain interacts with threonine 276 to control membrane association. PLoS One 2013; 8:e82084. [PMID: 24303080 PMCID: PMC3841123 DOI: 10.1371/journal.pone.0082084] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2012] [Accepted: 10/30/2013] [Indexed: 01/08/2023] Open
Abstract
Cell migration is regulated by a number of small GTPases, including members of the Arf family. Cytohesins, a family of Arf-activating proteins, have been extensively implicated in the regulation of Arfs during migration and cell shape change. Membrane association of both the Arf and its activating protein is a prerequisite for Arf activation. Therefore regulating the extent of cytohesin membrane association is a mechanism for controlling the initiation of cell movement. We have discovered a novel intramolecular interaction that controls the association of cytohesins with membranes. The presence of the coiled-coil domain reduces the association of cytohesin 2 with membranes. We demonstrate that this domain interacts with more C-terminal regions of the protein. This interaction is independent of another previously identified autoinhibitory conformation. A threonine residue (T276) in the cytohesin 2 PH domain is a target for phosphorylation by Akt. Mutation of this threonine to aspartic acid, to mimic phosphorylation, disrupts the binding of the coiled-coil domain to c-terminal regions and promotes membrane association of cytohesin 2. The presence of a second autoinhibitory interaction in the cytohesins suggests that these proteins can act a signal integrators that stimulate migration only after receive multiple pro-migratory signals.
Collapse
Affiliation(s)
- Kevin G. Hiester
- Department of Biochemistry and Molecular Biology, Pennsylvania State University, University Park, Pennsylvania, United States of America
| | - Lorraine C. Santy
- Department of Biochemistry and Molecular Biology, Pennsylvania State University, University Park, Pennsylvania, United States of America
- * E-mail:
| |
Collapse
|
49
|
An alteration in ELMOD3, an Arl2 GTPase-activating protein, is associated with hearing impairment in humans. PLoS Genet 2013; 9:e1003774. [PMID: 24039609 PMCID: PMC3764207 DOI: 10.1371/journal.pgen.1003774] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2013] [Accepted: 07/24/2013] [Indexed: 12/30/2022] Open
Abstract
Exome sequencing coupled with homozygosity mapping was used to identify a transition mutation (c.794T>C; p.Leu265Ser) in ELMOD3 at the DFNB88 locus that is associated with nonsyndromic deafness in a large Pakistani family, PKDF468. The affected individuals of this family exhibited pre-lingual, severe-to-profound degrees of mixed hearing loss. ELMOD3 belongs to the engulfment and cell motility (ELMO) family, which consists of six paralogs in mammals. Several members of the ELMO family have been shown to regulate a subset of GTPases within the Ras superfamily. However, ELMOD3 is a largely uncharacterized protein that has no previously known biochemical activities. We found that in rodents, within the sensory epithelia of the inner ear, ELMOD3 appears most pronounced in the stereocilia of cochlear hair cells. Fluorescently tagged ELMOD3 co-localized with the actin cytoskeleton in MDCK cells and actin-based microvilli of LLC-PK1-CL4 epithelial cells. The p.Leu265Ser mutation in the ELMO domain impaired each of these activities. Super-resolution imaging revealed instances of close association of ELMOD3 with actin at the plasma membrane of MDCK cells. Furthermore, recombinant human GST-ELMOD3 exhibited GTPase activating protein (GAP) activity against the Arl2 GTPase, which was completely abolished by the p.Leu265Ser mutation. Collectively, our data provide the first insights into the expression and biochemical properties of ELMOD3 and highlight its functional links to sound perception and actin cytoskeleton. Autosomal recessive nonsyndromic hearing loss is a genetically heterogeneous disorder. Here, we report a severe-to-profound mixed hearing loss locus, DFNB88 on chromosome 2p12-p11.2. Exome enrichment followed by massive parallel sequencing revealed a c.794T>C transition mutation in ELMOD3 that segregated with DFNB88-associated hearing loss in a large Pakistani family. This transition mutation is predicted to substitute a highly invariant leucine residue with serine (p.Leu265Ser) in the engulfment and cell motility (ELMO) domain of the protein. No biological activity has been described previously for the ELMOD3 protein. We investigated the biochemical properties and ELMOD3 expression to gain mechanistic insights into the function of ELMOD3 in the inner ear. In rodent inner ears, ELMOD3 immunoreactivity was observed in the cochlear and vestibular hair cells and supporting cells. However, ELMOD3 appears most pronounced in the stereocilia of cochlear hair cells. Ex vivo, ELMOD3 is associated with actin-based structures, and this link is impaired by the DFNB88 mutation. ELMOD3 exhibited GAP activity against Arl2, a small GTPase, providing a potential functional link between Arf family signaling and stereocilia actin-based cytoskeletal architecture. Our study provides new insights into the molecules that are necessary for the development and/or function of inner ear sensory cells.
Collapse
|
50
|
Structural basis for membrane recruitment and allosteric activation of cytohesin family Arf GTPase exchange factors. Proc Natl Acad Sci U S A 2013; 110:14213-8. [PMID: 23940353 PMCID: PMC3761562 DOI: 10.1073/pnas.1301883110] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
Membrane recruitment of cytohesin family Arf guanine nucleotide exchange factors depends on interactions with phosphoinositides and active Arf GTPases that, in turn, relieve autoinhibition of the catalytic Sec7 domain through an unknown structural mechanism. Here, we show that Arf6-GTP relieves autoinhibition by binding to an allosteric site that includes the autoinhibitory elements in addition to the PH domain. The crystal structure of a cytohesin-3 construct encompassing the allosteric site in complex with the head group of phosphatidyl inositol 3,4,5-trisphosphate and N-terminally truncated Arf6-GTP reveals a large conformational rearrangement, whereby autoinhibition can be relieved by competitive sequestration of the autoinhibitory elements in grooves at the Arf6/PH domain interface. Disposition of the known membrane targeting determinants on a common surface is compatible with multivalent membrane docking and subsequent activation of Arf substrates, suggesting a plausible model through which membrane recruitment and allosteric activation could be structurally integrated.
Collapse
|