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Sugawara T, Matsu-Ura H, Inagaki R, Kawamura T, Tanaka M, Hara Y, Saito K, Fukaya M, Moriguchi S, Sakagami H. EFA6A, a Guanine Nucleotide Exchange Factor for Arf6, Regulates Developmental Stage-Dependent Spine Morphogenesis, Synaptic Plasticity, and Long-Term Memory in the Hippocampus. Mol Neurobiol 2025:10.1007/s12035-025-05009-x. [PMID: 40335791 DOI: 10.1007/s12035-025-05009-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2025] [Accepted: 04/29/2025] [Indexed: 05/09/2025]
Abstract
EFA6A is a guanine nucleotide exchange factor for ADP ribosylation factor 6 (Arf6), a small GTPase involved in membrane trafficking and actin cytoskeleton remodeling. While EFA6A-Arf6 signaling has been shown to regulate dendritic spine formation and maintenance in cultured neurons, its role in higher brain functions remains unclear in vivo. Here, we generated mice lacking two EFA6A splicing isoforms, EFA6A and EFA6As, to examine their role in regulating spine morphology and hippocampus-dependent learning and memory. The loss of EFA6A and EFA6As caused reduced dendritic spine density in developing CA1 pyramidal neurons, whereas dendritic spines aberrantly increased in adults. Furthermore, the mutant mice also showed impaired maintenance of long-term potentiation (LTP) at Schaffer collateral-CA1 synapses in the hippocampus and memory retention in the passive avoidance test. These findings provide the first in vivo evidence that the EFA6A isoforms, EFA6A and EFA6As, collectively regulate spine formation bidirectionally in a developmental stage-dependent manner, which is likely to underlie hippocampal synaptic plasticity and memory formation.
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Affiliation(s)
- Takeyuki Sugawara
- Department of Anatomy, Kitasato University School of Medicine, 1-15-1 Kitazato, Minami-ku, Sagamihara, Kanagawa, 252-0374, Japan
| | - Hikaru Matsu-Ura
- Department of Anatomy, Kitasato University School of Medicine, 1-15-1 Kitazato, Minami-ku, Sagamihara, Kanagawa, 252-0374, Japan
| | - Ryo Inagaki
- Research Center for Pharmaceutical Development, Graduate School of Pharmaceutical Sciences, Tohoku University, 6-3 Aramaki-Aoba, Aoba-ku, Sendai, Miyagi, 980-8578, Japan
| | - Taichi Kawamura
- Department of Anatomy, Kitasato University School of Medicine, 1-15-1 Kitazato, Minami-ku, Sagamihara, Kanagawa, 252-0374, Japan
| | - Manabu Tanaka
- Bio-Imaging Center, Kitasato University School of Medicine, 1-15-1 Kitazato, Minami-ku, Sagamihara, Kanagawa, 252-0374, Japan
| | - Yoshinobu Hara
- Department of Anatomy, Kitasato University School of Medicine, 1-15-1 Kitazato, Minami-ku, Sagamihara, Kanagawa, 252-0374, Japan
| | - Koji Saito
- Department of Anatomy, Kitasato University School of Medicine, 1-15-1 Kitazato, Minami-ku, Sagamihara, Kanagawa, 252-0374, Japan
| | - Masahiro Fukaya
- Department of Anatomy, Kitasato University School of Medicine, 1-15-1 Kitazato, Minami-ku, Sagamihara, Kanagawa, 252-0374, Japan
- Department of Anatomical Science, School of Allied Health Sciences, Kitasato University, 1-15-1 Kitazato, Minami-ku, Sagamihara, Kanagawa, 252-0373, Japan
| | - Shigeki Moriguchi
- Research Center for Pharmaceutical Development, Graduate School of Pharmaceutical Sciences, Tohoku University, 6-3 Aramaki-Aoba, Aoba-ku, Sendai, Miyagi, 980-8578, Japan
| | - Hiroyuki Sakagami
- Department of Anatomy, Kitasato University School of Medicine, 1-15-1 Kitazato, Minami-ku, Sagamihara, Kanagawa, 252-0374, Japan.
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Fukaya M, Ibuchi K, Sugawara T, Itakura M, Ito A, Shiroshima T, Hara Y, Okamoto H, Luton F, Sakagami H. EFA6A, an Exchange Factor for Arf6, Regulates NGF-Dependent TrkA Recycling From Early Endosomes and Neurite Outgrowth in PC12 Cells. Traffic 2024; 25:e12936. [PMID: 38725127 DOI: 10.1111/tra.12936] [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: 03/22/2023] [Revised: 12/18/2023] [Accepted: 12/26/2023] [Indexed: 06/03/2024]
Abstract
Endosomal trafficking of TrkA is a critical process for nerve growth factor (NGF)-dependent neuronal cell survival and differentiation. The small GTPase ADP-ribosylation factor 6 (Arf6) is implicated in NGF-dependent processes in PC12 cells through endosomal trafficking and actin cytoskeleton reorganization. However, the regulatory mechanism for Arf6 in NGF signaling is largely unknown. In this study, we demonstrated that EFA6A, an Arf6-specific guanine nucleotide exchange factor, was abundantly expressed in PC12 cells and that knockdown of EFA6A significantly inhibited NGF-dependent Arf6 activation, TrkA recycling from early endosomes to the cell surface, prolonged ERK1/2 phosphorylation, and neurite outgrowth. We also demonstrated that EFA6A forms a protein complex with TrkA through its N-terminal region, thereby enhancing its catalytic activity for Arf6. Similarly, we demonstrated that EFA6A forms a protein complex with TrkA in cultured dorsal root ganglion (DRG) neurons. Furthermore, cultured DRG neurons from EFA6A knockout mice exhibited disturbed NGF-dependent TrkA trafficking compared with wild-type neurons. These findings provide the first evidence for EFA6A as a key regulator of NGF-dependent TrkA trafficking and signaling.
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Affiliation(s)
- Masahiro Fukaya
- Department of Anatomy, Kitasato University School of Medicine, Sagamihara, Japan
| | - Kanta Ibuchi
- Department of Anatomy, Kitasato University School of Medicine, Sagamihara, Japan
| | - Takeyuki Sugawara
- Department of Anatomy, Kitasato University School of Medicine, Sagamihara, Japan
| | - Makoto Itakura
- Department of Biochemistry, Kitasato University School of Medicine, Sagamihara, Japan
| | - Akiko Ito
- Department of Anesthesiology, Kitasato University School of Medicine, Sagamihara, Japan
| | - Tomoko Shiroshima
- Department of Anatomy, Kitasato University School of Medicine, Sagamihara, Japan
| | - Yoshinobu Hara
- Department of Anatomy, Kitasato University School of Medicine, Sagamihara, Japan
| | - Hirotsugu Okamoto
- Department of Anesthesiology, Kitasato University School of Medicine, Sagamihara, Japan
| | - Frédéric Luton
- CNRS, Institut de Pharmacologie Moléculaire et Cellulaire (IPMC), Université Côte d'Azur, Valbonne, France
| | - Hiroyuki Sakagami
- Department of Anatomy, Kitasato University School of Medicine, Sagamihara, Japan
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Litif CG, Flom LT, Sandum KL, Hodgins SL, Vaccaro L, Stitzel JA, Blouin NA, Mannino MC, Gigley JP, Schoborg TA, Bobadilla AC. Differential genetic expression within reward-specific ensembles in mice. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2023.11.02.565378. [PMID: 37961222 PMCID: PMC10635086 DOI: 10.1101/2023.11.02.565378] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/15/2023]
Abstract
Maladaptive reward seeking is a hallmark of cocaine use disorder. To develop therapeutic targets, it is critical to understand the neurobiological changes specific to cocaine-seeking without altering the seeking of natural rewards, e.g., sucrose. The prefrontal cortex (PFC) and the nucleus accumbens core (NAcore) are known regions associated with cocaine- and sucrose-seeking ensembles, i.e., a sparse population of co-activated neurons. Within ensembles, transcriptomic alterations in the PFC and NAcore underlie the learning and persistence of cocaine- and sucrose-seeking behavior. However, transcriptomes exclusively driving cocaine seeking independent from sucrose seeking have not yet been defined using a within-subject approach. Using Ai14:cFos-TRAP2 transgenic mice in a dual cocaine and sucrose self-administration model, we fluorescently sorted (FACS) and characterized (RNAseq) the transcriptomes defining cocaine- and sucrose-seeking ensembles. We found reward- and region-specific transcriptomic changes that will help develop clinically relevant genetic approaches to decrease cocaine-seeking behavior without altering non-drug reward-based positive reinforcement.
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Affiliation(s)
- Carl G. Litif
- School of Pharmacy, University of Wyoming, Laramie, Wyoming, USA
| | - Levi T. Flom
- School of Pharmacy, University of Wyoming, Laramie, Wyoming, USA
| | | | | | - Lucio Vaccaro
- School of Pharmacy, University of Wyoming, Laramie, Wyoming, USA
| | - Jerry A. Stitzel
- Department of Integrative Physiology, University of Colorado Boulder, Boulder, Colorado, USA
- Institute for Behavioral Genetics, University of Colorado Boulder, Boulder, Colorado, USA
| | - Nicolas A. Blouin
- Department of Molecular Biology, University of Wyoming, Laramie, Wyoming, USA
| | | | - Jason P. Gigley
- Department of Molecular Biology, University of Wyoming, Laramie, Wyoming, USA
| | - Todd A. Schoborg
- Department of Molecular Biology, University of Wyoming, Laramie, Wyoming, USA
| | - Ana-Clara Bobadilla
- School of Pharmacy, University of Wyoming, Laramie, Wyoming, USA
- Department of Biomedical Sciences, Colorado State University, Fort Collins, Colorado, USA
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Partisani M, Baron CL, Ghossoub R, Fayad R, Pagnotta S, Abélanet S, Macia E, Brau F, Lacas-Gervais S, Benmerah A, Luton F, Franco M. EFA6A, an exchange factor for Arf6, regulates early steps in ciliogenesis. J Cell Sci 2021; 134:237326. [PMID: 33483367 DOI: 10.1242/jcs.249565] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2020] [Accepted: 11/20/2020] [Indexed: 12/13/2022] Open
Abstract
Ciliogenesis is a coordinated process initiated by the recruitment and fusion of pre-ciliary vesicles at the distal appendages of the mother centriole through mechanisms that remain unclear. Here, we report that EFA6A (also known as PSD), an exchange factor for the small G protein Arf6, is involved in early stage of ciliogenesis by promoting the fusion of distal appendage vesicles forming the ciliary vesicle. EFA6A is present in the vicinity of the mother centriole before primary cilium assembly and prior to the arrival of Arl13B-containing vesicles. During ciliogenesis, EFA6A initially accumulates at the mother centriole and later colocalizes with Arl13B along the ciliary membrane. EFA6A depletion leads to the inhibition of ciliogenesis, the absence of centrosomal Rab8-positive structures and the accumulation of Arl13B-positive vesicles around the distal appendages. Our results uncover a novel fusion machinery, comprising EFA6A, Arf6 and Arl13B, that controls the coordinated fusion of ciliary vesicles docked at the distal appendages of the mother centriole.
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Affiliation(s)
- Mariagrazia Partisani
- Institut de Pharmacologie Moléculaire et Cellulaire (IPMC), UMR 7275 CNRS-Université Côte d'Azur, 660, route des lucioles, 06560 Valbonne, France
| | - Carole L Baron
- Institut de Pharmacologie Moléculaire et Cellulaire (IPMC), UMR 7275 CNRS-Université Côte d'Azur, 660, route des lucioles, 06560 Valbonne, France
| | - Rania Ghossoub
- Centre de Recherche en Cancérologie de Marseille (CRCM), Inserm, U1068-CNRS UMR7258, Aix-Marseille Université, Institut Paoli-Calmettes, 13009 Marseille, France
| | - Racha Fayad
- Institut de Pharmacologie Moléculaire et Cellulaire (IPMC), UMR 7275 CNRS-Université Côte d'Azur, 660, route des lucioles, 06560 Valbonne, France
| | - Sophie Pagnotta
- Centre Commun de Microscopie Appliquée (CCMA), Université Côte d'Azur Parc Valrose, 06103 Nice cedex 2, France
| | - Sophie Abélanet
- Institut de Pharmacologie Moléculaire et Cellulaire (IPMC), UMR 7275 CNRS-Université Côte d'Azur, 660, route des lucioles, 06560 Valbonne, France
| | - Eric Macia
- Institut de Pharmacologie Moléculaire et Cellulaire (IPMC), UMR 7275 CNRS-Université Côte d'Azur, 660, route des lucioles, 06560 Valbonne, France
| | - Frédéric Brau
- Institut de Pharmacologie Moléculaire et Cellulaire (IPMC), UMR 7275 CNRS-Université Côte d'Azur, 660, route des lucioles, 06560 Valbonne, France
| | - Sandra Lacas-Gervais
- Centre Commun de Microscopie Appliquée (CCMA), Université Côte d'Azur Parc Valrose, 06103 Nice cedex 2, France
| | - Alexandre Benmerah
- Université de Paris, Imagine Institute, Laboratory of Inherited Kidney Diseases, INSERM UMR 1163, F-75015, Paris, France
| | - Frédéric Luton
- Institut de Pharmacologie Moléculaire et Cellulaire (IPMC), UMR 7275 CNRS-Université Côte d'Azur, 660, route des lucioles, 06560 Valbonne, France
| | - Michel Franco
- Institut de Pharmacologie Moléculaire et Cellulaire (IPMC), UMR 7275 CNRS-Université Côte d'Azur, 660, route des lucioles, 06560 Valbonne, France
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Cataloguing and Selection of mRNAs Localized to Dendrites in Neurons and Regulated by RNA-Binding Proteins in RNA Granules. Biomolecules 2020; 10:biom10020167. [PMID: 31978946 PMCID: PMC7072219 DOI: 10.3390/biom10020167] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2019] [Revised: 01/18/2020] [Accepted: 01/20/2020] [Indexed: 12/15/2022] Open
Abstract
Spatiotemporal translational regulation plays a key role in determining cell fate and function. Specifically, in neurons, local translation in dendrites is essential for synaptic plasticity and long-term memory formation. To achieve local translation, RNA-binding proteins in RNA granules regulate target mRNA stability, localization, and translation. To date, mRNAs localized to dendrites have been identified by comprehensive analyses. In addition, mRNAs associated with and regulated by RNA-binding proteins have been identified using various methods in many studies. However, the results obtained from these numerous studies have not been compiled together. In this review, we have catalogued mRNAs that are localized to dendrites and are associated with and regulated by the RNA-binding proteins fragile X mental retardation protein (FMRP), RNA granule protein 105 (RNG105, also known as Caprin1), Ras-GAP SH3 domain binding protein (G3BP), cytoplasmic polyadenylation element binding protein 1 (CPEB1), and staufen double-stranded RNA binding proteins 1 and 2 (Stau1 and Stau2) in RNA granules. This review provides comprehensive information on dendritic mRNAs, the neuronal functions of mRNA-encoded proteins, the association of dendritic mRNAs with RNA-binding proteins in RNA granules, and the effects of RNA-binding proteins on mRNA regulation. These findings provide insights into the mechanistic basis of protein-synthesis-dependent synaptic plasticity and memory formation and contribute to future efforts to understand the physiological implications of local regulation of dendritic mRNAs in neurons.
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The C-terminal domain of EFA6A interacts directly with F-actin and assembles F-actin bundles. Sci Rep 2019; 9:19209. [PMID: 31844082 PMCID: PMC6915736 DOI: 10.1038/s41598-019-55630-9] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2019] [Accepted: 11/28/2019] [Indexed: 01/08/2023] Open
Abstract
The Arf6-specific exchange factor EFA6 is involved in the endocytic/recycling pathway for different cargos. In addition EFA6 acts as a powerful actin cytoskeleton organizer, a function required for its role in the establishment of the epithelial cell polarity and in neuronal morphogenesis. We previously showed that the C-terminus of EFA6 (EFA6-Ct) is the main domain which contributes to actin reorganization. Here, by in vitro and in vivo experiments, we sought to decipher, at the molecular level, how EFA6 controls the dynamic and structuring of actin filaments. We showed that EFA6-Ct interferes with actin polymerization by interacting with and capping actin filament barbed ends. Further, in the presence of actin mono-filaments, the addition of EFA6-Ct triggered the formation of actin bundles. In cells, when the EFA6-Ct was directed to the plasma membrane, as is the case for the full-length protein, its expression induced the formation of membrane protrusions enriched in actin cables. Collectively our data explain, at least in part, how EFA6 plays an essential role in actin organization by interacting with and bundling F-actin.
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Saegusa S, Fukaya M, Kakegawa W, Tanaka M, Katsumata O, Sugawara T, Hara Y, Itakura M, Okubo T, Sato T, Yuzaki M, Sakagami H. Mice lacking EFA6C/Psd2, a guanine nucleotide exchange factor for Arf6, exhibit lower Purkinje cell synaptic density but normal cerebellar motor functions. PLoS One 2019; 14:e0216960. [PMID: 31095630 PMCID: PMC6522047 DOI: 10.1371/journal.pone.0216960] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2019] [Accepted: 05/01/2019] [Indexed: 11/18/2022] Open
Abstract
ADP ribosylation factor 6 (Arf6) is a small GTPase that regulates various neuronal events including formation of the axon, dendrites and dendritic spines, and synaptic plasticity through actin cytoskeleton remodeling and endosomal trafficking. EFA6C, also known as Psd2, is a guanine nucleotide exchange factor for Arf6 that is preferentially expressed in the cerebellar cortex of adult mice, particularly in Purkinje cells. However, the roles of EFA6C in cerebellar development and functions remain unknown. In this study, we generated global EFA6C knockout (KO) mice using the CRISPR/Cas9 system and investigated their cerebellar phenotypes by histological and behavioral analyses. Histological analyses revealed that EFA6C KO mice exhibited normal gross anatomy of the cerebellar cortex, in terms of the thickness and cellularity of each layer, morphology of Purkinje cells, and distribution patterns of parallel fibers, climbing fibers, and inhibitory synapses. Electron microscopic observation of the cerebellar molecular layer revealed that the density of asymmetric synapses of Purkinje cells was significantly lower in EFA6C KO mice compared with wild-type control mice. However, behavioral analyses using accelerating rotarod and horizontal optokinetic response tests failed to detect any differences in motor coordination, learning or adaptation between the control and EFA6C KO mice. These results suggest that EFA6C plays ancillary roles in cerebellar development and motor functions.
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Affiliation(s)
- Shintaro Saegusa
- Department of Anatomy, Kitasato University School of Medicine, Sagamihara, Kanagawa, Japan
| | - Masahiro Fukaya
- Department of Anatomy, Kitasato University School of Medicine, Sagamihara, Kanagawa, Japan
| | - Wataru Kakegawa
- Department of Physiology, Keio University School of Medicine, Tokyo, Japan
| | - Manabu Tanaka
- Bio-imaging Center, Kitasato University School of Medicine, Sagamihara, Kanagawa, Japan
| | - Osamu Katsumata
- 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
| | - Makoto Itakura
- Department of Biochemistry, Kitasato University School of Medicine, Sagamihara, Kanagawa, Japan
| | - Tadashi Okubo
- Department of Laboratory Animal Science, Kitasato University School of Medicine, Sagamihara, Kanagawa, Japan
| | - Toshiya Sato
- Department of Laboratory Animal Science, Kitasato University School of Medicine, Sagamihara, Kanagawa, Japan
| | - Michisuke Yuzaki
- Department of Physiology, Keio University School of Medicine, Tokyo, Japan
| | - Hiroyuki Sakagami
- Department of Anatomy, Kitasato University School of Medicine, Sagamihara, Kanagawa, Japan
- * E-mail:
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Milanini J, Fayad R, Partisani M, Lecine P, Borg JP, Franco M, Luton F. EFA6 regulates lumen formation through alpha-actinin 1. J Cell Sci 2017; 131:jcs.209361. [DOI: 10.1242/jcs.209361] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2017] [Accepted: 12/11/2017] [Indexed: 01/07/2023] Open
Abstract
A key step of epithelial morphogenesis is the creation of the lumen. Luminogenesis by hollowing proceeds through the fusion of apical vesicles at cell-cell contact. The small nascent lumens grow through extension, coalescence and enlargement coordinated with cell division to give rise to a single central lumen. Here, using MDCK cells grown in 3D-culture, we show that EFA6A participates in luminogenesis. EFA6A recruits α-actinin 1 (ACTN1) through direct binding. In polarized cells, ACTN1 was found to be enriched at the tight junction where it acts as a primary effector of EFA6A for normal luminogenesis. Both proteins are essential for the lumen extension and enlargement, where they mediate their effect by regulating the cortical acto-myosin contractility. Finally, ACTN1 was also found to act as an effector for the isoform EFA6B in the human mammary tumoral MCF7 cell line. EFA6B restored the glandular morphology of this tumoral cell line in an ACTN1-dependent manner. Thus, we identified new regulators of cyst luminogenesis essential for the proper maturation of a newly-formed lumen into a single central lumen.
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Affiliation(s)
- Julie Milanini
- Université Côte d'Azur, CNRS, Institut de Pharmacologie Moléculaire et Cellulaire (IPMC), Valbonne, France
| | - Racha Fayad
- Université Côte d'Azur, CNRS, Institut de Pharmacologie Moléculaire et Cellulaire (IPMC), Valbonne, France
| | - Mariagrazia Partisani
- Université Côte d'Azur, CNRS, Institut de Pharmacologie Moléculaire et Cellulaire (IPMC), Valbonne, France
| | - Patrick Lecine
- Centre de Recherche en Cancérologie de Marseille (CRCM), "Cell Polarity, Cell Signalling and Cancer", Equipe Labellisée Ligue Contre le Cancer, Inserm U1068, Marseille, F-13009, France; CNRS, UMR7258, Marseille, F-13009, France; Institut Paoli-Calmettes, Marseille, F-13009, France; Aix-Marseille University, UM105, Marseille, F-13284, France
- present address: BIOASTER, Lyon, France
| | - Jean-Paul Borg
- Centre de Recherche en Cancérologie de Marseille (CRCM), "Cell Polarity, Cell Signalling and Cancer", Equipe Labellisée Ligue Contre le Cancer, Inserm U1068, Marseille, F-13009, France; CNRS, UMR7258, Marseille, F-13009, France; Institut Paoli-Calmettes, Marseille, F-13009, France; Aix-Marseille University, UM105, Marseille, F-13284, France
| | - Michel Franco
- Université Côte d'Azur, CNRS, Institut de Pharmacologie Moléculaire et Cellulaire (IPMC), Valbonne, France
| | - Frédéric Luton
- Université Côte d'Azur, CNRS, Institut de Pharmacologie Moléculaire et Cellulaire (IPMC), Valbonne, France
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Fukaya M, Ohta S, Hara Y, Tamaki H, Sakagami H. Distinct subcellular localization of alternative splicing variants of EFA6D, a guanine nucleotide exchange factor for Arf6, in the mouse brain. J Comp Neurol 2016; 524:2531-52. [PMID: 27241101 DOI: 10.1002/cne.24048] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2015] [Revised: 03/31/2016] [Accepted: 05/24/2016] [Indexed: 11/07/2022]
Abstract
EFA6D (guanine nucleotide exchange factor for ADP-ribosylation factor 6 [Arf6]D) is also known as EFA6R, Psd3, and HCA67. It is the fourth member of the EFA6 family with guanine nucleotide exchange activity for Arf6, a small guanosine triphosphatase (GTPase) that regulates endosomal trafficking and actin cytoskeleton remodeling. We propose a classification and nomenclature of 10 EFA6D variants deposited in the GenBank database as EFA6D1a, 1b, 1c, 1d, 1s, 2a, 2b, 2c, 2d, and 2s based on the combination of N-terminal and C-terminal insertions. Polymerase chain reaction analysis showed the expression of all EFA6D variants except for variants a and d in the adult mouse brain. Immunoblotting analysis with novel variant-specific antibodies showed the endogenous expression of EFA6D1b, EFA6D1c, and EFA6D1s at the protein level, with the highest expression being EFA6D1s, in the brain. Immunoblotting analysis of forebrain subcellular fractions showed the distinct subcellular distribution of EFA6D1b/c and EFA6D1s. The immunohistochemical analysis revealed distinct but overlapping immunoreactive patterns between EFA6D1b/c and EFA6D1s in the mouse brain. In immunoelectron microscopic analyses of the hippocampal CA3 region, EFA6D1b/c was present predominantly in the mossy fiber axons of dentate granule cells, whereas EFA6D1s was present abundantly in the cell bodies, dendritic shafts, and spines of hippocampal pyramidal cells. These results provide the first anatomical evidence suggesting the functional diversity of EFA6D variants, particularly EFA6D1b/c and EFA6D1s, in neurons. J. Comp. Neurol. 524:2531-2552, 2016. © 2016 Wiley Periodicals, Inc.
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Affiliation(s)
- Masahiro Fukaya
- Department of Anatomy, Kitasato University School of Medicine, Sagamihara, Kanagawa, 252-0374, Japan
| | - Shingo Ohta
- Department of Anatomy, Kitasato University School of Medicine, Sagamihara, Kanagawa, 252-0374, Japan
| | - Yoshinobu Hara
- Department of Anatomy, Kitasato University School of Medicine, Sagamihara, Kanagawa, 252-0374, Japan
| | - Hideaki Tamaki
- Department of Anatomy, Kitasato University School of Medicine, Sagamihara, Kanagawa, 252-0374, Japan
| | - Hiroyuki Sakagami
- Department of Anatomy, Kitasato University School of Medicine, Sagamihara, Kanagawa, 252-0374, Japan
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10
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Li XZ, Zhang SN, Lu F, Liu SM. Microarray Expression Analysis for the Paradoxical Roles of Acanthopanax senticosus Harms in Treating α-Synucleinopathies. Phytother Res 2015; 30:243-52. [PMID: 26612828 DOI: 10.1002/ptr.5522] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2015] [Revised: 10/26/2015] [Accepted: 11/01/2015] [Indexed: 01/04/2023]
Abstract
α-Synuclein is a key player in the pathogenesis of neurodegenerative disorders with Lewy bodies. Our previous studies have also showed that Acanthopanax senticosus harms (AS) could significantly suppress α-synuclein overexpression and toxicity. Identifying the RNAs related to α-synucleinopathies may facilitate understanding the pathogenesis of the diseases and the safe application of AS in the clinic. Microarray expression profiling of long non-coding RNAs (lncRNAs) and mRNAs was undertaken in control non-transgenic and human α-synuclein transgenic mice. The effects of AS on central nervous system (CNS) in pathology and physiology were investigated based on the lncRNA/mRNA targets analysis. In total, 341 lncRNAs and 279 mRNAs were differentially expressed by α-synuclein stimulus, among which 29 lncRNAs and 25 mRNAs were involved in the anti-α-synucleinopathies mechanism of AS. However, the levels of 19/29 lncRNAs and 12/25 mRNAs in AS group were similar to those in α-synuclein group, which may cause potential neurotoxicity analogous to α-synuclein. This study demonstrated that some of lncRNAs/mRNAs were involved in α-synuclein related pathophysiology, and AS produced the bidirectional effects on CNS under pathological and physiological conditions.
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Affiliation(s)
- Xu-zhao Li
- Chinese Medicine Toxicological Laboratory, Heilongjiang University of Chinese Medicine, Harbin, 150040, China.,Department of Pharmacy, GuiYang College of Traditional Chinese Medicine, GuiYang, 550025, China
| | - Shuai-nan Zhang
- Chinese Medicine Toxicological Laboratory, Heilongjiang University of Chinese Medicine, Harbin, 150040, China
| | - Fang Lu
- Chinese Medicine Toxicological Laboratory, Heilongjiang University of Chinese Medicine, Harbin, 150040, China
| | - Shu-min Liu
- Chinese Medicine Toxicological Laboratory, Heilongjiang University of Chinese Medicine, Harbin, 150040, China.,Drug Safety Evaluation Center, Heilongjiang University of Chinese Medicine, Harbin, 150040, China
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11
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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: 1.4] [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.
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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
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12
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Fukaya M, Fukushima D, Hara Y, Sakagami H. EFA6A, a guanine nucleotide exchange factor for Arf6, interacts with sorting nexin-1 and regulates neurite outgrowth. J Neurochem 2013; 129:21-36. [PMID: 24261326 DOI: 10.1111/jnc.12524] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2013] [Revised: 10/09/2013] [Accepted: 11/04/2013] [Indexed: 01/11/2023]
Abstract
The membrane trafficking and actin cytoskeleton remodeling mediated by ADP ribosylation factor 6 (Arf6) are functionally linked to various neuronal processes including neurite formation and maintenance, neurotransmitter release, and receptor internalization. EFA6A is an Arf6-specific guanine nucleotide exchange factor that is abundantly expressed in the brain. In this study, we identified sorting nexin-1 (SNX1), a retromer component that is implicated in endosomal sorting and trafficking, as a novel interacting partner for EFA6A by yeast two-hybrid screening. The interaction was mediated by the C-terminal region of EFA6A and a BAR domain of SNX1, and further confirmed by pull-down assay and immunoprecipitation from mouse brain lysates. In situ hybridization analysis demonstrated the widespread expression of SNX1 in the mouse brain, which overlapped with the expression of EFA6A in the forebrain. Immunofluorescent analysis revealed the partial colocalization of EFA6A and SNX1 in the dendritic fields of the hippocampus. Immunoelectron microscopic analysis revealed the overlapping subcellular localization of EFA6A and SNX1 at the post-synaptic density and endosomes in dendritic spines. In Neuro-2a neuroblastoma cells, expression of either EFA6A or SNX1 induced neurite outgrowth, which was further enhanced by co-expression of EFA6A and SNX1. The present findings suggest a novel mechanism by which EFA6A regulates Arf6-mediated neurite formation through the interaction with SNX1.
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Affiliation(s)
- Masahiro Fukaya
- Department of Anatomy, Kitasato University School of Medicine, Sagamihara, Kanagawa, Japan
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13
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Ugolotti R, Mesejo P, Zongaro S, Bardoni B, Berto G, Bianchi F, Molineris I, Giacobini M, Cagnoni S, Di Cunto F. Visual search of neuropil-enriched RNAs from brain in situ hybridization data through the image analysis pipeline hippo-ATESC. PLoS One 2013; 8:e74481. [PMID: 24040258 PMCID: PMC3767670 DOI: 10.1371/journal.pone.0074481] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2013] [Accepted: 07/30/2013] [Indexed: 11/23/2022] Open
Abstract
Motivation RNA molecules specifically enriched in the neuropil of neuronal cells and in particular in dendritic spines are of great interest for neurobiology in virtue of their involvement in synaptic structure and plasticity. The systematic recognition of such molecules is therefore a very important task. High resolution images of RNA in situ hybridization experiments contained in the Allen Brain Atlas (ABA) represent a very rich resource to identify them and have been so far exploited for this task through human-expert analysis. However, software tools that may automatically address the same objective are not very well developed. Results In this study we describe an automatic method for exploring in situ hybridization data and discover neuropil-enriched RNAs in the mouse hippocampus. We called it Hippo-ATESC (Automatic Texture Extraction from the Hippocampal region using Soft Computing). Bioinformatic validation showed that the Hippo-ATESC is very efficient in the recognition of RNAs which are manually identified by expert curators as neuropil-enriched on the same image series. Moreover, we show that our method can also highlight genes revealed by microdissection-based methods but missed by human visual inspection. We experimentally validated our approach by identifying a non-coding transcript enriched in mouse synaptosomes. The code is freely available on the web at http://ibislab.ce.unipr.it/software/hippo/.
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Affiliation(s)
- Roberto Ugolotti
- Department of Information Engineering, University of Parma, Parma, Italy
| | - Pablo Mesejo
- Department of Information Engineering, University of Parma, Parma, Italy
| | - Samantha Zongaro
- CNRS UMR 7275, Institute of Molecular and Cellular Pharmacology, University of Nice-Sophia Antipolis, Valbonne, France
| | - Barbara Bardoni
- CNRS UMR 7275, Institute of Molecular and Cellular Pharmacology, University of Nice-Sophia Antipolis, Valbonne, France
| | - Gaia Berto
- Molecular Biotechnology Center, Department of Molecular Biotechnology and Health Sciences, University of Torino, Torino, Italy
| | - Federico Bianchi
- Molecular Biotechnology Center, Department of Molecular Biotechnology and Health Sciences, University of Torino, Torino, Italy
| | - Ivan Molineris
- Molecular Biotechnology Center, Department of Molecular Biotechnology and Health Sciences, University of Torino, Torino, Italy
| | - Mario Giacobini
- Department of Veterinary Sciences, University of Torino, Torino, Italy
| | - Stefano Cagnoni
- Department of Information Engineering, University of Parma, Parma, Italy
- * E-mail: (SC); (FDC)
| | - Ferdinando Di Cunto
- Molecular Biotechnology Center, Department of Molecular Biotechnology and Health Sciences, University of Torino, Torino, Italy
- Neuroscience Institute of Torino (NIT), University of Torino, Torino, Italy
- * E-mail: (SC); (FDC)
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14
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Torii T, Miyamoto Y, Nakamura K, Maeda M, Yamauchi J, Tanoue A. Arf6 guanine-nucleotide exchange factor, cytohesin-2, interacts with actinin-1 to regulate neurite extension. Cell Signal 2012; 24:1872-82. [DOI: 10.1016/j.cellsig.2012.05.016] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2012] [Revised: 05/16/2012] [Accepted: 05/24/2012] [Indexed: 10/28/2022]
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15
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Mo J, Choi S, Ahn PG, Sun W, Lee HW, Kim H. PDZ-scaffold protein, Tamalin promotes dendritic outgrowth and arborization in rat hippocampal neuron. Biochem Biophys Res Commun 2012; 422:250-5. [PMID: 22569042 DOI: 10.1016/j.bbrc.2012.04.136] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2012] [Accepted: 04/25/2012] [Indexed: 02/02/2023]
Abstract
Tamalin is a scaffold protein known to regulate membrane trafficking through its interaction with cytohesin-2/ARNO, guanine nucleotide exchange factor (GEF) on ADP-ribosylation factor (Arf) 1/6, and induces actin reorganization. However, the neuronal function of Tamalin is not well understood. Here, we report that Tamalin participates in neurite development through the association with exchange factor for Arf6 (EFA6A)/Arf6 signaling. In immature hippocampal neuron, Tamalin knockdown markedly reduced the dendritic outgrowth, the number of dendritic tips and the levels of filamentous actin (F-actin) and microtubule-associated protein 2 (MAP2) in dendrites. In addition, Tamalin colocalized with EFA6A and Arf6 in the dendritic shaft. Tamalin knockdown reduced the number, size, and intensity of endogenous EFA6A cluster, whereas overexpression of Tamalin showed opposite effects compared with those of knockdown. These results suggest that Tamalin is responsible for neuronal dendritic development via regulation of EFA6A/Arf6-mediated cytoskeleton dynamics.
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Affiliation(s)
- Jiwon Mo
- Department of Anatomy and Division of Brain Korea 21 Biomedical Science, College of Medicine, Korea University, 126-1, 5-Ka, Anam-Dong, Seongbuk-Gu, Seoul 136-705, Republic of Korea
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16
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Théard D, Labarrade F, Partisani M, Milanini J, Sakagami H, Fon EA, Wood SA, Franco M, Luton F. USP9x-mediated deubiquitination of EFA6 regulates de novo tight junction assembly. EMBO J 2010; 29:1499-509. [PMID: 20339350 DOI: 10.1038/emboj.2010.46] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2010] [Accepted: 03/03/2010] [Indexed: 11/09/2022] Open
Abstract
In epithelial cells, the tight junction (TJ) functions as a permeability barrier and is involved in cellular differentiation and proliferation. Although many TJ proteins have been characterized, little is known about the sequence of events and temporal regulation of TJ assembly in response to adhesion cues. We report here that the deubiquitinating enzyme USP9x has a critical function in TJ biogenesis by controlling the levels of the exchange factor for Arf6 (EFA6), a protein shown to facilitate TJ formation, during a narrow temporal window preceding the establishment of cell polarity. At steady state, EFA6 is constitutively ubiquitinated and turned over by the proteasome. However, at newly forming contacts, USP9x-mediated deubiquitination protects EFA6 from proteasomal degradation, leading to a transient increase in EFA6 levels. Consistent with this model, USP9x and EFA6 transiently co-localize at primordial epithelial junctions. Furthermore, knockdown of either EFA6 or USP9x impairs TJ biogenesis and EFA6 overexpression rescues TJ biogenesis in USP9x-knockdown cells. As the loss of cell polarity is a critical event in the metastatic spread of cancer, these findings may help to understand the pathology of human carcinomas.
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Affiliation(s)
- Delphine Théard
- Institut de Pharmacologie Moléculaire et Cellulaire, Université de Nice Sophia-Antipolis, Valbonne, France
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