Molecular Mechanisms of Neuronal Actin Cytoskeleton Dynamics

A special issue of Cells (ISSN 2073-4409). This special issue belongs to the section "Cell Motility and Adhesion".

Deadline for manuscript submissions: closed (31 July 2021) | Viewed by 50955

Special Issue Editors


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Guest Editor
Philipps-Universität Marburg, Marburg, Germany
Interests: actin cytoskeleton regulation; neuron differentiation; synapse formation and function

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Guest Editor
Minerva Foundation Institute for Medical Research, Helsinki, Finland
Interests: actin cytoskeleton regulation; dendritic spines; axon initial segment (AIS)

Special Issue Information

Dear Colleagues,

The actin cytoskeleton is a major determinant of neuron morphology and function. Actin filaments (F-actin) are enriched in subcellular structures such as growth cones or dendritic spines, which are relevant for directed neurite outgrowth or synapse physiology, respectively. While numerous signaling molecules and actin-binding proteins have been implicated in the organization and dynamics of the neuronal actin cytoskeleton, our knowledge of actin regulatory mechanisms in neurons is still fragmented. Moreover, additional neuronal F-actin-based structures such as dendritic F-actin patches, longitudinal actin fibers or periodic actin rings have been discovered more recently, and their regulation and function remain largely unknown.

This Special Issue on “Molecular Mechanisms of Neuronal Actin Cytoskeleton Dynamics” aims at collecting high-quality research articles, review articles, and communications on all aspects of neuronal actin cytoskeleton regulation and function, with a focus on molecular and cell biology studies.

We look forward to your contributions.

Prof. Dr. Marco Rust
Dr. Pirta Hotulainen
Guest Editors

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Keywords

  • neuritogenesis
  • growth cones
  • neuron differentiation
  • axon initial segment
  • synaptogenesis
  • dendritic spine
  • synaptic plasticity

Published Papers (13 papers)

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Research

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21 pages, 3064 KiB  
Article
Specificity and Redundancy of Profilin 1 and 2 Function in Brain Development and Neuronal Structure
by Marina Di Domenico, Melanie Jokwitz, Walter Witke and Pietro Pilo Boyl
Cells 2021, 10(9), 2310; https://doi.org/10.3390/cells10092310 - 03 Sep 2021
Cited by 8 | Viewed by 2680
Abstract
Profilin functions have been discussed in numerous cellular processes, including actin polymerization. One puzzling aspect is the concomitant expression of more than one profilin isoform in most tissues. In neuronal precursors and in neurons, profilin 1 and profilin 2 are co-expressed, but their [...] Read more.
Profilin functions have been discussed in numerous cellular processes, including actin polymerization. One puzzling aspect is the concomitant expression of more than one profilin isoform in most tissues. In neuronal precursors and in neurons, profilin 1 and profilin 2 are co-expressed, but their specific and redundant functions in brain morphogenesis are still unclear. Using a conditional knockout mouse model to inactivate both profilins in the developing CNS, we found that threshold levels of profilin are necessary for the maintenance of the neuronal stem-cell compartment and the generation of the differentiated neurons, irrespective of the specific isoform. During embryonic development, profilin 1 is more abundant than profilin 2; consequently, modulation of profilin 1 levels resulted in a more severe phenotype than depletion of profilin 2. Interestingly, the relevance of the isoforms was reversed in the postnatal brain. Morphology of mature neurons showed a stronger dependence on profilin 2, since this is the predominant isoform in neurons. Our data highlight redundant functions of profilins in neuronal precursor expansion and differentiation, as well as in the maintenance of pyramidal neuron dendritic arborization. The specific profilin isoform is less relevant; however, a threshold profilin level is essential. We propose that the common activity of profilin 1 and profilin 2 in actin dynamics is responsible for the observed compensatory effects. Full article
(This article belongs to the Special Issue Molecular Mechanisms of Neuronal Actin Cytoskeleton Dynamics)
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13 pages, 2680 KiB  
Article
Cortactin Contributes to Activity-Dependent Modulation of Spine Actin Dynamics and Spatial Memory Formation
by Jonas Cornelius, Klemens Rottner, Martin Korte and Kristin Michaelsen-Preusse
Cells 2021, 10(7), 1835; https://doi.org/10.3390/cells10071835 - 20 Jul 2021
Cited by 3 | Viewed by 2409
Abstract
Postsynaptic structures on excitatory neurons, dendritic spines, are actin-rich. It is well known that actin-binding proteins regulate actin dynamics and by this means orchestrate structural plasticity during the development of the brain, as well as synaptic plasticity mediating learning and memory processes. The [...] Read more.
Postsynaptic structures on excitatory neurons, dendritic spines, are actin-rich. It is well known that actin-binding proteins regulate actin dynamics and by this means orchestrate structural plasticity during the development of the brain, as well as synaptic plasticity mediating learning and memory processes. The actin-binding protein cortactin is localized to pre- and postsynaptic structures and translocates in a stimulus-dependent manner between spines and the dendritic compartment, thereby indicating a crucial role for synaptic plasticity and neuronal function. While it is known that cortactin directly binds F-actin, the Arp2/3 complex important for actin nucleation and branching as well as other factors involved in synaptic plasticity processes, its precise role in modulating actin remodeling in neurons needs to be deciphered. In this study, we characterized the general neuronal function of cortactin in knockout mice. Interestingly, we found that the loss of cortactin leads to deficits in hippocampus-dependent spatial memory formation. This impairment is correlated with a prominent dysregulation of functional and structural plasticity. Additional evidence shows impaired long-term potentiation in cortactin knockout mice together with a complete absence of structural spine plasticity. These phenotypes might at least in part be explained by alterations in the activity-dependent modulation of synaptic actin in cortactin-deficient neurons. Full article
(This article belongs to the Special Issue Molecular Mechanisms of Neuronal Actin Cytoskeleton Dynamics)
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25 pages, 8940 KiB  
Article
Integrin-Linked Kinase (ILK) Plays an Important Role in the Laminin-Dependent Development of Dorsal Root Ganglia during Chicken Embryogenesis
by Ewa Mrówczyńska and Antonina Joanna Mazur
Cells 2021, 10(7), 1666; https://doi.org/10.3390/cells10071666 - 02 Jul 2021
Cited by 1 | Viewed by 3105
Abstract
Integrin-linked kinase (ILK) is mainly localized in focal adhesions where it interacts and modulates the downstream signaling of integrins affecting cell migration, adhesion, and survival. The interaction of dorsal root ganglia (DRG) cells, being part of the peripheral nervous system (PNS), with the [...] Read more.
Integrin-linked kinase (ILK) is mainly localized in focal adhesions where it interacts and modulates the downstream signaling of integrins affecting cell migration, adhesion, and survival. The interaction of dorsal root ganglia (DRG) cells, being part of the peripheral nervous system (PNS), with the extracellular matrix (ECM) via integrins is crucial for proper PNS development. A few studies have focused on ILK’s role in PNS development, but none of these have focused on chicken. Therefore, we decided to investigate ILK’s role in the development of Gallus gallus domesticus’s DRG. First, using RT-PCR, Western blotting, and in situ hybridization, we show that ILK is expressed in DRG. Next, by immunocytochemistry, we show ILK’s localization both intracellularly and on the cell membrane of DRG neurons and Schwann cell precursors (SCPs). Finally, we describe ILK’s involvement in multiple aspects of DRG development by performing functional experiments in vitro. IgG-mediated interruption of ILK’s action improved DRG neurite outgrowth, modulated their directionality, stimulated SCPs migration, and impacted growth cone morphology in the presence of laminin-1 or laminin-1 mimicking peptide IKVAV. Taken together, our results show that ILK is important for chicken PNS development, probably via its exposure to the ECM. Full article
(This article belongs to the Special Issue Molecular Mechanisms of Neuronal Actin Cytoskeleton Dynamics)
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14 pages, 4816 KiB  
Article
Functional Redundancy of Cyclase-Associated Proteins CAP1 and CAP2 in Differentiating Neurons
by Felix Schneider, Isabell Metz, Sharof Khudayberdiev and Marco B. Rust
Cells 2021, 10(6), 1525; https://doi.org/10.3390/cells10061525 - 17 Jun 2021
Cited by 12 | Viewed by 2499
Abstract
Cyclase-associated proteins (CAPs) are evolutionary-conserved actin-binding proteins with crucial functions in regulating actin dynamics, the spatiotemporally controlled assembly and disassembly of actin filaments (F-actin). Mammals possess two family members (CAP1 and CAP2) with different expression patterns. Unlike most other tissues, both CAPs are [...] Read more.
Cyclase-associated proteins (CAPs) are evolutionary-conserved actin-binding proteins with crucial functions in regulating actin dynamics, the spatiotemporally controlled assembly and disassembly of actin filaments (F-actin). Mammals possess two family members (CAP1 and CAP2) with different expression patterns. Unlike most other tissues, both CAPs are expressed in the brain and present in hippocampal neurons. We recently reported crucial roles for CAP1 in growth cone function, neuron differentiation, and neuron connectivity in the mouse brain. Instead, CAP2 controls dendritic spine morphology and synaptic plasticity, and its dysregulation contributes to Alzheimer’s disease pathology. These findings are in line with a model in which CAP1 controls important aspects during neuron differentiation, while CAP2 is relevant in differentiated neurons. We here report CAP2 expression during neuron differentiation and its enrichment in growth cones. We therefore hypothesized that CAP2 is relevant not only in excitatory synapses, but also in differentiating neurons. However, CAP2 inactivation neither impaired growth cone morphology and motility nor neuron differentiation. Moreover, CAP2 mutant mice did not display any obvious changes in brain anatomy. Hence, differently from CAP1, CAP2 was dispensable for neuron differentiation and brain development. Interestingly, overexpression of CAP2 rescued not only growth cone size in CAP1-deficient neurons, but also their morphology and differentiation. Our data provide evidence for functional redundancy of CAP1 and CAP2 in differentiating neurons, and they suggest compensatory mechanisms in single mutant neurons. Full article
(This article belongs to the Special Issue Molecular Mechanisms of Neuronal Actin Cytoskeleton Dynamics)
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21 pages, 5656 KiB  
Article
Deletion of the Actin-Associated Tropomyosin Tpm3 Leads to Reduced Cell Complexity in Cultured Hippocampal Neurons—New Insights into the Role of the C-Terminal Region of Tpm3.1
by Tamara Tomanić, Claire Martin, Holly Stefen, Esmeralda Parić, Peter Gunning and Thomas Fath
Cells 2021, 10(3), 715; https://doi.org/10.3390/cells10030715 - 23 Mar 2021
Cited by 7 | Viewed by 2711
Abstract
Tropomyosins (Tpms) have been described as master regulators of actin, with Tpm3 products shown to be involved in early developmental processes, and the Tpm3 isoform Tpm3.1 controlling changes in the size of neuronal growth cones and neurite growth. Here, we used primary mouse [...] Read more.
Tropomyosins (Tpms) have been described as master regulators of actin, with Tpm3 products shown to be involved in early developmental processes, and the Tpm3 isoform Tpm3.1 controlling changes in the size of neuronal growth cones and neurite growth. Here, we used primary mouse hippocampal neurons of C57/Bl6 wild type and Bl6Tpm3flox transgenic mice to carry out morphometric analyses in response to the absence of Tpm3 products, as well as to investigate the effect of C-terminal truncation on the ability of Tpm3.1 to modulate neuronal morphogenesis. We found that the knock-out of Tpm3 leads to decreased neurite length and complexity, and that the deletion of two amino acid residues at the C-terminus of Tpm3.1 leads to more detrimental changes in neurite morphology than the deletion of six amino acid residues. We also found that Tpm3.1 that lacks the 6 C-terminal amino acid residues does not associate with stress fibres, does not segregate to the tips of neurites, and does not impact the amount of the filamentous actin pool at the axonal growth cones, as opposed to Tpm3.1, which lacks the two C-terminal amino acid residues. Our study provides further insight into the role of both Tpm3 products and the C-terminus of Tpm3.1, and it forms the basis for future studies that aim to identify the molecular mechanisms underlying Tpm3.1 targeting to different subcellular compartments. Full article
(This article belongs to the Special Issue Molecular Mechanisms of Neuronal Actin Cytoskeleton Dynamics)
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Review

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20 pages, 4095 KiB  
Review
Control of Synapse Structure and Function by Actin and Its Regulators
by Juliana E. Gentile, Melissa G. Carrizales and Anthony J. Koleske
Cells 2022, 11(4), 603; https://doi.org/10.3390/cells11040603 - 09 Feb 2022
Cited by 14 | Viewed by 4288
Abstract
Neurons transmit and receive information at specialized junctions called synapses. Excitatory synapses form at the junction between a presynaptic axon terminal and a postsynaptic dendritic spine. Supporting the shape and function of these junctions is a complex network of actin filaments and its [...] Read more.
Neurons transmit and receive information at specialized junctions called synapses. Excitatory synapses form at the junction between a presynaptic axon terminal and a postsynaptic dendritic spine. Supporting the shape and function of these junctions is a complex network of actin filaments and its regulators. Advances in microscopic techniques have enabled studies of the organization of actin at synapses and its dynamic regulation. In addition to highlighting recent advances in the field, we will provide a brief historical perspective of the understanding of synaptic actin at the synapse. We will also highlight key neuronal functions regulated by actin, including organization of proteins in the pre- and post- synaptic compartments and endocytosis of ion channels. We review the evidence that synapses contain distinct actin pools that differ in their localization and dynamic behaviors and discuss key functions for these actin pools. Finally, whole exome sequencing of humans with neurodevelopmental and psychiatric disorders has identified synaptic actin regulators as key disease risk genes. We briefly summarize how genetic variants in these genes impact neurotransmission via their impact on synaptic actin. Full article
(This article belongs to the Special Issue Molecular Mechanisms of Neuronal Actin Cytoskeleton Dynamics)
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17 pages, 2444 KiB  
Review
Drosophila Dendritic Arborisation Neurons: Fantastic Actin Dynamics and Where to Find Them
by Lukas Kilo, Tomke Stürner, Gaia Tavosanis and Anna B. Ziegler
Cells 2021, 10(10), 2777; https://doi.org/10.3390/cells10102777 - 16 Oct 2021
Cited by 5 | Viewed by 3308
Abstract
Neuronal dendrites receive, integrate, and process numerous inputs and therefore serve as the neuron’s “antennae”. Dendrites display extreme morphological diversity across different neuronal classes to match the neuron’s specific functional requirements. Understanding how this structural diversity is specified is therefore important for shedding [...] Read more.
Neuronal dendrites receive, integrate, and process numerous inputs and therefore serve as the neuron’s “antennae”. Dendrites display extreme morphological diversity across different neuronal classes to match the neuron’s specific functional requirements. Understanding how this structural diversity is specified is therefore important for shedding light on information processing in the healthy and diseased nervous system. Popular models for in vivo studies of dendrite differentiation are the four classes of dendritic arborization (c1da–c4da) neurons of Drosophila larvae with their class-specific dendritic morphologies. Using da neurons, a combination of live-cell imaging and computational approaches have delivered information on the distinct phases and the time course of dendrite development from embryonic stages to the fully developed dendritic tree. With these data, we can start approaching the basic logic behind differential dendrite development. A major role in the definition of neuron-type specific morphologies is played by dynamic actin-rich processes and the regulation of their properties. This review presents the differences in the growth programs leading to morphologically different dendritic trees, with a focus on the key role of actin modulatory proteins. In addition, we summarize requirements and technological progress towards the visualization and manipulation of such actin regulators in vivo. Full article
(This article belongs to the Special Issue Molecular Mechanisms of Neuronal Actin Cytoskeleton Dynamics)
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46 pages, 5061 KiB  
Review
Cofilin and Actin Dynamics: Multiple Modes of Regulation and Their Impacts in Neuronal Development and Degeneration
by James R. Bamburg, Laurie S. Minamide, O’Neil Wiggan, Lubna H. Tahtamouni and Thomas B. Kuhn
Cells 2021, 10(10), 2726; https://doi.org/10.3390/cells10102726 - 12 Oct 2021
Cited by 44 | Viewed by 7312
Abstract
Proteins of the actin depolymerizing factor (ADF)/cofilin family are ubiquitous among eukaryotes and are essential regulators of actin dynamics and function. Mammalian neurons express cofilin-1 as the major isoform, but ADF and cofilin-2 are also expressed. All isoforms bind preferentially and cooperatively along [...] Read more.
Proteins of the actin depolymerizing factor (ADF)/cofilin family are ubiquitous among eukaryotes and are essential regulators of actin dynamics and function. Mammalian neurons express cofilin-1 as the major isoform, but ADF and cofilin-2 are also expressed. All isoforms bind preferentially and cooperatively along ADP-subunits in F-actin, affecting the filament helical rotation, and when either alone or when enhanced by other proteins, promotes filament severing and subunit turnover. Although self-regulating cofilin-mediated actin dynamics can drive motility without post-translational regulation, cells utilize many mechanisms to locally control cofilin, including cooperation/competition with other proteins. Newly identified post-translational modifications function with or are independent from the well-established phosphorylation of serine 3 and provide unexplored avenues for isoform specific regulation. Cofilin modulates actin transport and function in the nucleus as well as actin organization associated with mitochondrial fission and mitophagy. Under neuronal stress conditions, cofilin-saturated F-actin fragments can undergo oxidative cross-linking and bundle together to form cofilin-actin rods. Rods form in abundance within neurons around brain ischemic lesions and can be rapidly induced in neurites of most hippocampal and cortical neurons through energy depletion or glutamate-induced excitotoxicity. In ~20% of rodent hippocampal neurons, rods form more slowly in a receptor-mediated process triggered by factors intimately connected to disease-related dementias, e.g., amyloid-β in Alzheimer’s disease. This rod-inducing pathway requires a cellular prion protein, NADPH oxidase, and G-protein coupled receptors, e.g., CXCR4 and CCR5. Here, we will review many aspects of cofilin regulation and its contribution to synaptic loss and pathology of neurodegenerative diseases. Full article
(This article belongs to the Special Issue Molecular Mechanisms of Neuronal Actin Cytoskeleton Dynamics)
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26 pages, 1669 KiB  
Review
Dendritic Spine Initiation in Brain Development, Learning and Diseases and Impact of BAR-Domain Proteins
by Pushpa Khanal and Pirta Hotulainen
Cells 2021, 10(9), 2392; https://doi.org/10.3390/cells10092392 - 12 Sep 2021
Cited by 20 | Viewed by 5151
Abstract
Dendritic spines are small, bulbous protrusions along neuronal dendrites where most of the excitatory synapses are located. Dendritic spine density in normal human brain increases rapidly before and after birth achieving the highest density around 2–8 years. Density decreases during adolescence, reaching a [...] Read more.
Dendritic spines are small, bulbous protrusions along neuronal dendrites where most of the excitatory synapses are located. Dendritic spine density in normal human brain increases rapidly before and after birth achieving the highest density around 2–8 years. Density decreases during adolescence, reaching a stable level in adulthood. The changes in dendritic spines are considered structural correlates for synaptic plasticity as well as the basis of experience-dependent remodeling of neuronal circuits. Alterations in spine density correspond to aberrant brain function observed in various neurodevelopmental and neuropsychiatric disorders. Dendritic spine initiation affects spine density. In this review, we discuss the importance of spine initiation in brain development, learning, and potential complications resulting from altered spine initiation in neurological diseases. Current literature shows that two Bin Amphiphysin Rvs (BAR) domain-containing proteins, MIM/Mtss1 and SrGAP3, are involved in spine initiation. We review existing literature and open databases to discuss whether other BAR-domain proteins could also take part in spine initiation. Finally, we discuss the potential molecular mechanisms on how BAR-domain proteins could regulate spine initiation. Full article
(This article belongs to the Special Issue Molecular Mechanisms of Neuronal Actin Cytoskeleton Dynamics)
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24 pages, 1286 KiB  
Review
LIM-Kinases in Synaptic Plasticity, Memory, and Brain Diseases
by Youssif Ben Zablah, Haiwang Zhang, Radu Gugustea and Zhengping Jia
Cells 2021, 10(8), 2079; https://doi.org/10.3390/cells10082079 - 13 Aug 2021
Cited by 23 | Viewed by 4610
Abstract
Learning and memory require structural and functional modifications of synaptic connections, and synaptic deficits are believed to underlie many brain disorders. The LIM-domain-containing protein kinases (LIMK1 and LIMK2) are key regulators of the actin cytoskeleton by affecting the actin-binding protein, cofilin. In addition, [...] Read more.
Learning and memory require structural and functional modifications of synaptic connections, and synaptic deficits are believed to underlie many brain disorders. The LIM-domain-containing protein kinases (LIMK1 and LIMK2) are key regulators of the actin cytoskeleton by affecting the actin-binding protein, cofilin. In addition, LIMK1 is implicated in the regulation of gene expression by interacting with the cAMP-response element-binding protein. Accumulating evidence indicates that LIMKs are critically involved in brain function and dysfunction. In this paper, we will review studies on the roles and underlying mechanisms of LIMKs in the regulation of long-term potentiation (LTP) and depression (LTD), the most extensively studied forms of long-lasting synaptic plasticity widely regarded as cellular mechanisms underlying learning and memory. We will also discuss the involvement of LIMKs in the regulation of the dendritic spine, the structural basis of synaptic plasticity, and memory formation. Finally, we will discuss recent progress on investigations of LIMKs in neurological and mental disorders, including Alzheimer’s, Parkinson’s, Williams–Beuren syndrome, schizophrenia, and autism spectrum disorders. Full article
(This article belongs to the Special Issue Molecular Mechanisms of Neuronal Actin Cytoskeleton Dynamics)
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12 pages, 1162 KiB  
Review
Actin Cytoskeleton Role in the Maintenance of Neuronal Morphology and Long-Term Memory
by Raphael Lamprecht
Cells 2021, 10(7), 1795; https://doi.org/10.3390/cells10071795 - 15 Jul 2021
Cited by 14 | Viewed by 3138
Abstract
Evidence indicates that long-term memory formation creates long-lasting changes in neuronal morphology within a specific neuronal network that forms the memory trace. Dendritic spines, which include most of the excitatory synapses in excitatory neurons, are formed or eliminated by learning. These changes may [...] Read more.
Evidence indicates that long-term memory formation creates long-lasting changes in neuronal morphology within a specific neuronal network that forms the memory trace. Dendritic spines, which include most of the excitatory synapses in excitatory neurons, are formed or eliminated by learning. These changes may be long-lasting and correlate with memory strength. Moreover, learning-induced changes in the morphology of existing spines can also contribute to the formation of the neuronal network that underlies memory. Altering spines morphology after memory consolidation can erase memory. These observations strongly suggest that learning-induced spines modifications can constitute the changes in synaptic connectivity within the neuronal network that form memory and that stabilization of this network maintains long-term memory. The formation and elimination of spines and other finer morphological changes in spines are mediated by the actin cytoskeleton. The actin cytoskeleton forms networks within the spine that support its structure. Therefore, it is believed that the actin cytoskeleton mediates spine morphogenesis induced by learning. Any long-lasting changes in the spine morphology induced by learning require the preservation of the spine actin cytoskeleton network to support and stabilize the spine new structure. However, the actin cytoskeleton is highly dynamic, and the turnover of actin and its regulatory proteins that determine and support the actin cytoskeleton network structure is relatively fast. Molecular models, suggested here, describe ways to overcome the dynamic nature of the actin cytoskeleton and the fast protein turnover and to support an enduring actin cytoskeleton network within the spines, spines stability and long-term memory. These models are based on long-lasting changes in actin regulatory proteins concentrations within the spine or the formation of a long-lasting scaffold and the ability for its recurring rebuilding within the spine. The persistence of the actin cytoskeleton network within the spine is suggested to support long-lasting spine structure and the maintenance of long-term memory. Full article
(This article belongs to the Special Issue Molecular Mechanisms of Neuronal Actin Cytoskeleton Dynamics)
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23 pages, 715 KiB  
Review
Fe65: A Scaffolding Protein of Actin Regulators
by Vanessa Augustin and Stefan Kins
Cells 2021, 10(7), 1599; https://doi.org/10.3390/cells10071599 - 25 Jun 2021
Cited by 8 | Viewed by 3789
Abstract
The scaffolding protein family Fe65, composed of Fe65, Fe65L1, and Fe65L2, was identified as an interaction partner of the amyloid precursor protein (APP), which plays a key function in Alzheimer’s disease. All three Fe65 family members possess three highly conserved interaction domains, forming [...] Read more.
The scaffolding protein family Fe65, composed of Fe65, Fe65L1, and Fe65L2, was identified as an interaction partner of the amyloid precursor protein (APP), which plays a key function in Alzheimer’s disease. All three Fe65 family members possess three highly conserved interaction domains, forming complexes with diverse binding partners that can be assigned to different cellular functions, such as transactivation of genes in the nucleus, modulation of calcium homeostasis and lipid metabolism, and regulation of the actin cytoskeleton. In this article, we rule out putative new intracellular signaling mechanisms of the APP-interacting protein Fe65 in the regulation of actin cytoskeleton dynamics in the context of various neuronal functions, such as cell migration, neurite outgrowth, and synaptic plasticity. Full article
(This article belongs to the Special Issue Molecular Mechanisms of Neuronal Actin Cytoskeleton Dynamics)
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15 pages, 1173 KiB  
Review
The Role of Protein Arginine Methylation as Post-Translational Modification on Actin Cytoskeletal Components in Neuronal Structure and Function
by Britta Qualmann and Michael M. Kessels
Cells 2021, 10(5), 1079; https://doi.org/10.3390/cells10051079 - 01 May 2021
Cited by 4 | Viewed by 3846
Abstract
The brain encompasses a complex network of neurons with exceptionally elaborated morphologies of their axonal (signal-sending) and dendritic (signal-receiving) parts. De novo actin filament formation is one of the major driving and steering forces for the development and plasticity of the neuronal arbor. [...] Read more.
The brain encompasses a complex network of neurons with exceptionally elaborated morphologies of their axonal (signal-sending) and dendritic (signal-receiving) parts. De novo actin filament formation is one of the major driving and steering forces for the development and plasticity of the neuronal arbor. Actin filament assembly and dynamics thus require tight temporal and spatial control. Such control is particularly effective at the level of regulating actin nucleation-promoting factors, as these are key components for filament formation. Arginine methylation represents an important post-translational regulatory mechanism that had previously been mainly associated with controlling nuclear processes. We will review and discuss emerging evidence from inhibitor studies and loss-of-function models for protein arginine methyltransferases (PRMTs), both in cells and whole organisms, that unveil that protein arginine methylation mediated by PRMTs represents an important regulatory mechanism in neuritic arbor formation, as well as in dendritic spine induction, maturation and plasticity. Recent results furthermore demonstrated that arginine methylation regulates actin cytosolic cytoskeletal components not only as indirect targets through additional signaling cascades, but can also directly control an actin nucleation-promoting factor shaping neuronal cells—a key process for the formation of neuronal networks in vertebrate brains. Full article
(This article belongs to the Special Issue Molecular Mechanisms of Neuronal Actin Cytoskeleton Dynamics)
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