1
|
Carrington G, Fatima U, Caramujo I, Lewis T, Casas-Mao D, Peckham M. A multiscale approach reveals the molecular architecture of the autoinhibited kinesin KIF5A. J Biol Chem 2024; 300:105713. [PMID: 38309508 PMCID: PMC10907169 DOI: 10.1016/j.jbc.2024.105713] [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: 11/06/2023] [Revised: 01/23/2024] [Accepted: 01/26/2024] [Indexed: 02/05/2024] Open
Abstract
Kinesin-1 is a microtubule motor that transports cellular cargo along microtubules. KIF5A is one of three kinesin-1 isoforms in humans, all of which are autoinhibited by an interaction between the motor and an IAK motif in the proximal region of the C-terminal tail. The C-terminal tail of KIF5A is ∼80 residues longer than the other two kinesin-1 isoforms (KIF5B and KIF5C) and it is unclear if it contributes to autoinhibition. Mutations in KIF5A cause neuronal diseases and could affect autoinhibition, as reported for a mutation that skips exon 27, altering its C-terminal sequence. Here, we combined negative-stain electron microscopy, crosslinking mass spectrometry (XL-MS) and AlphaFold2 structure prediction to determine the molecular architecture of the full-length autoinhibited KIF5A homodimer, in the absence of light chains. We show that KIF5A forms a compact, bent conformation, through a bend between coiled-coils 2 and 3, around P687. XL-MS of WT KIF5A revealed extensive interactions between residues in the motor, between coiled-coil 1 and the motor, between coiled-coils 1 and 2, with coiled-coils 3 and 4, and the proximal region of the C-terminal tail and the motor in the autoinhibited state, but not between the distal C-terminal region and the rest of the molecule. While negative-stain electron microscopy of exon-27 KIF5A splice mutant showed the presence of autoinhibited molecules, XL-MS analysis suggested that its autoinhibited state is more labile. Our model offers a conceptual framework for understanding how mutations within the motor and stalk domain may affect motor activity.
Collapse
Affiliation(s)
- Glenn Carrington
- Faculty of Biological Sciences, Astbury Centre for Structural Biology and the School of Molecular and Cellular Biology, University of Leeds, Leeds, UK
| | - Uzrama Fatima
- Faculty of Biological Sciences, Astbury Centre for Structural Biology and the School of Molecular and Cellular Biology, University of Leeds, Leeds, UK
| | - Ines Caramujo
- Faculty of Biological Sciences, Astbury Centre for Structural Biology and the School of Molecular and Cellular Biology, University of Leeds, Leeds, UK
| | - Tarek Lewis
- Faculty of Biological Sciences, Astbury Centre for Structural Biology and the School of Molecular and Cellular Biology, University of Leeds, Leeds, UK
| | - David Casas-Mao
- Faculty of Biological Sciences, Astbury Centre for Structural Biology and the School of Molecular and Cellular Biology, University of Leeds, Leeds, UK
| | - Michelle Peckham
- Faculty of Biological Sciences, Astbury Centre for Structural Biology and the School of Molecular and Cellular Biology, University of Leeds, Leeds, UK.
| |
Collapse
|
2
|
Alfadil E, Bradke F. Moving through the crowd. Where are we at understanding physiological axon growth? Semin Cell Dev Biol 2023; 140:63-71. [PMID: 35817655 DOI: 10.1016/j.semcdb.2022.07.001] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2022] [Revised: 07/01/2022] [Accepted: 07/04/2022] [Indexed: 01/28/2023]
Abstract
Axon growth enables the rapid wiring of the central nervous system. Understanding this process is a prerequisite to retriggering it under pathological conditions, such as a spinal cord injury, to elicit axon regeneration. The last decades saw progress in understanding the mechanisms underlying axon growth. Most of these studies employed cultured neurons grown on flat surfaces. Only recently studies on axon growth were performed in 3D. In these studies, physiological environments exposed more complex and dynamic aspects of axon development. Here, we describe current views on axon growth and highlight gaps in our knowledge. We discuss how axons interact with the extracellular matrix during development and the role of the growth cone and its cytoskeleton within. Finally, we propose that the time is ripe to study axon growth in a more physiological setting. This will help us uncover the physiologically relevant mechanisms underlying axon growth, and how they can be reactivated to induce axon regeneration.
Collapse
Affiliation(s)
- Eissa Alfadil
- Laboratory of Axon Growth and Regeneration, Deutsches Zentrum für Neurodegenerative Erkrankungen (DZNE), Venusberg-Campus 1, Building 99, 53127, Bonn, Germany.
| | - Frank Bradke
- Laboratory of Axon Growth and Regeneration, Deutsches Zentrum für Neurodegenerative Erkrankungen (DZNE), Venusberg-Campus 1, Building 99, 53127, Bonn, Germany
| |
Collapse
|
3
|
Choi K, Lee J, Kang HJ. Myelination defects in the medial prefrontal cortex of Fkbp5 knockout mice. FASEB J 2021; 35:e21297. [PMID: 33410216 DOI: 10.1096/fj.202001883r] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2020] [Revised: 11/14/2020] [Accepted: 12/07/2020] [Indexed: 12/13/2022]
Abstract
The hypothalamic-pituitary-adrenal (HPA) axis plays a principal role in stress response regulation and has been implicated in the etiology of stress-related disorders. The HPA axis regulates the normal synthesis and release of glucocorticoids; dysregulation of the HPA axis causes abnormal responses to stress. FK506-binding protein 5 (FKBP5), a co-chaperone of heat shock protein 90 in the glucocorticoid receptor (GR) molecular complex, is a key GR sensitivity regulator. FKBP5 single nucleotide polymorphisms are associated with dysregulated HPA axis and increased risk of stress-related disorders, including posttraumatic stress disorder (PTSD) and depression. In this study, we profiled the microRNAs (miRNAs) in the medial prefrontal cortex of Fkbp5 knockout (Fkbp5-/- ) mice and identified the target genes of differentially expressed miRNAs using sequence-based miRNA target prediction. Gene ontology analysis revealed that the differentially expressed miRNAs were involved in nervous system development, regulation of cell migration, and intracellular signal transduction. The validation of the expression of predicted target genes using quantitative polymerase chain reaction revealed that the expression of axon development-related genes, specifically actin-binding LIM protein 1 (Ablim1), lemur tyrosine kinase 2 (Lmtk2), kinesin family member 5c (Kif5c), neurofascin (Nfasc), and ephrin type-A receptor 4 (Epha4), was significantly decreased, while that of brain-derived neurotrophic factor (Bdnf) was significantly increased in the brain of Fkbp5-/- mice. These results suggest that axonal development-related genes can serve as potential targets in future studies focused on understanding the pathophysiology of PTSD.
Collapse
Affiliation(s)
- Koeul Choi
- Department of Life Science, Chung-Ang University, Seoul, Korea
| | - Joonhee Lee
- Department of Life Science, Chung-Ang University, Seoul, Korea
| | - Hyo Jung Kang
- Department of Life Science, Chung-Ang University, Seoul, Korea
| |
Collapse
|
4
|
VAMP4 Maintains a Ca 2+-Sensitive Pool of Spontaneously Recycling Synaptic Vesicles. J Neurosci 2020; 40:5389-5401. [PMID: 32532887 DOI: 10.1523/jneurosci.2386-19.2020] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2019] [Revised: 05/29/2020] [Accepted: 06/05/2020] [Indexed: 11/21/2022] Open
Abstract
Spontaneous neurotransmitter release is a fundamental property of synapses in which neurotransmitter filled vesicles release their content independent of presynaptic action potentials (APs). Despite their seemingly random nature, these spontaneous fusion events can be regulated by Ca2+ signaling pathways. Here, we probed the mechanisms that maintain Ca2+ sensitivity of spontaneous release events in synapses formed between hippocampal neurons cultured from rats of both sexes. In this setting, we examined the potential role of vesicle-associated membrane protein 4 (VAMP4), a vesicular soluble N-ethylmaleimide-sensitive factor attachment protein receptor (SNARE) protein in spontaneous neurotransmission. Our results show that VAMP4 is required for Ca2+-dependent spontaneous excitatory neurotransmission, with a limited role in spontaneous inhibitory neurotransmission. Key residues in VAMP4 that regulate its retrieval as well as functional clathrin-mediated vesicle trafficking were essential for the maintenance of VAMP4-mediated spontaneous release. Moreover, high-frequency stimulation (HFS) that typically triggers asynchronous release and retrieval of VAMP4 from the plasma membrane also augmentsCa2+-sensitive spontaneous release for up to 30 min in a VAMP4-dependent manner. This VAMP4-mediated link between asynchronous and spontaneous excitatory neurotransmission might serve as a presynaptic substrate for synaptic plasticity coupling distinct forms of release.SIGNIFICANCE STATEMENT Spontaneous neurotransmitter release that occurs independent of presynaptic action potentials (APs) shows significant sensitivity to intracellular Ca2+ levels. In this study, we identify the vesicular soluble N-ethylmaleimide-sensitive factor attachment protein receptor (SNARE) molecule vesicle-associated membrane protein 4 (VAMP4) as a key component of the machinery that maintains these Ca2+-sensitive fraction of spontaneous release events. Following brief intense activity, VAMP4-dependent synaptic vesicle retrieval supports a pool of vesicles that fuse spontaneously in the long term. We propose that this vesicle trafficking pathway acts to shape spontaneous release and associated signaling based on previous activity history of synapses.
Collapse
|
5
|
Jin J, Ravindran P, Di Meo D, Püschel AW. Igf1R/InsR function is required for axon extension and corpus callosum formation. PLoS One 2019; 14:e0219362. [PMID: 31318893 PMCID: PMC6638864 DOI: 10.1371/journal.pone.0219362] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2018] [Accepted: 06/21/2019] [Indexed: 12/02/2022] Open
Abstract
One of the earliest steps during the development of the nervous system is the establishment of neuronal polarity and the formation of an axon. The intrinsic mechanisms that promote axon formation have been extensively analyzed. However, much less is known about the extrinsic signals that initiate axon formation. One of the candidates for these signals is Insulin-like growth factor 1 (Igf1) that acts through the Igf1 (Igf1R) and insulin receptors (InsR). Since Igf1R and InsR may act redundantly we analyzed conditional cortex-specific knockout mice that are deficient for both Igf1r and Insr to determine if they regulate the development of the cortex and the formation of axons in vivo. Our results show that Igf1R/InsR function is required for the normal development of the embryonic hippocampus and cingulate cortex while the lateral cortex does not show apparent defects in the Igf1r;Insr knockout. In the cingulate cortex, the number of intermediate progenitors and deep layer neurons is reduced and the corpus callosum is absent at E17. However, cortical organization and axon formation are not impaired in knockout embryos. In culture, cortical and hippocampal neurons from Igf1r;Insr knockout embryos extend an axon but the length of this axon is severely reduced. Our results indicate that Igf1R/InsR function is required for brain development in a region-specific manner and promotes axon growth but is not essential for neuronal polarization and migration in the developing brain.
Collapse
Affiliation(s)
- Jing Jin
- Institut für Molekulare Zellbiologie, University of Münster, Münster, Germany
- Cells-in-Motion Cluster of Excellence, University of Münster, Münster, Germany
| | | | - Danila Di Meo
- Institut für Molekulare Zellbiologie, University of Münster, Münster, Germany
- Cells-in-Motion Cluster of Excellence, University of Münster, Münster, Germany
| | - Andreas W. Püschel
- Institut für Molekulare Zellbiologie, University of Münster, Münster, Germany
- Cells-in-Motion Cluster of Excellence, University of Münster, Münster, Germany
- * E-mail:
| |
Collapse
|
6
|
Quiroga S, Bisbal M, Cáceres A. Regulation of plasma membrane expansion during axon formation. Dev Neurobiol 2017; 78:170-180. [PMID: 29090510 DOI: 10.1002/dneu.22553] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2017] [Revised: 10/28/2017] [Accepted: 10/29/2017] [Indexed: 12/14/2022]
Abstract
Here, will review current evidence regarding the signaling pathways and mechanisms underlying membrane addition at sites of active growth during axon formation. © 2017 Wiley Periodicals, Inc. Develop Neurobiol 78: 170-180, 2018.
Collapse
Affiliation(s)
- Santiago Quiroga
- Dpto. de Química Biológica Ranwel Caputto y Centro de Investigaciones en Química Biológica Córdoba (CIQUIBIC-CONICET) Av. Haya de la Torre s/n Ciudad Universitaria, Córdoba, Argentina.,Universidad Nacional de Córdoba (UNC) Av. Haya de la Torre s/n Ciudad Universitaria, Córdoba, Argentina
| | - Mariano Bisbal
- Universidad Nacional de Córdoba (UNC) Av. Haya de la Torre s/n Ciudad Universitaria, Córdoba, Argentina.,Instituto Mercedes y Martín Ferreyra (INIMEC-CONICET) Av. Friuli 2434, 5016, Córdoba, Argentina.,Instituto Universitario Ciencias Biomédicas de Córdoba (IUCBC), Av. Friuli 2786, 5016, Córdoba, Argentina
| | - Alfredo Cáceres
- Universidad Nacional de Córdoba (UNC) Av. Haya de la Torre s/n Ciudad Universitaria, Córdoba, Argentina.,Instituto Mercedes y Martín Ferreyra (INIMEC-CONICET) Av. Friuli 2434, 5016, Córdoba, Argentina.,Instituto Universitario Ciencias Biomédicas de Córdoba (IUCBC), Av. Friuli 2786, 5016, Córdoba, Argentina
| |
Collapse
|