scholarly journals IRSp53 coordinates AMPK and 14-3-3 signaling to regulate filopodia dynamics and directed cell migration

2019 ◽  
Vol 30 (11) ◽  
pp. 1285-1297 ◽  
Author(s):  
David J. Kast ◽  
Roberto Dominguez
Keyword(s):  
Cell Migration ◽  
Cancer Cell ◽  
Rho Gtpase ◽  
Cell Communication ◽  
Phosphorylation Sites ◽  
Bar Domain ◽  
Directed Cell Migration ◽  
Downstream Effectors ◽  
Dependent Inhibition ◽  
Membrane Protrusions

Filopodia are actin-filled membrane protrusions that play essential roles in cell motility and cell–cell communication and act as precursors of dendritic spines. IRSp53 is an essential regulator of filopodia formation, which couples Rho-GTPase signaling to actin cytoskeleton and membrane remodeling. IRSp53 has three major domains: an N-terminal inverse-BAR (I-BAR) domain, a Cdc42- and SH3-binding CRIB-PR domain, and an SH3 domain that binds downstream cytoskeletal effectors. Phosphorylation sites in the region between the CRIB-PR and SH3 domains mediate the binding of 14-3-3. Yet the mechanism by which 14-­3-3 regulates filopodia formation and dynamics and its role in cell migration are poorly understood. Here, we show that phosphorylation-dependent inhibition of IRSp53 by 14-3-3 counters activation by Cdc42 and cytoskeletal effectors, resulting in down-regulation of filopodia dynamics and cancer cell migration. In serum-starved cells, increased IRSp53 phosphorylation triggers 14-3-3 binding, which inhibits filopodia formation and dynamics, irrespective of whether IRSp53 is activated by Cdc42 or downstream effectors (Eps8, Ena/VASP). Pharmacological activation or inhibition of AMPK, respectively, increases or decreases the phosphorylation of two of three sites in IRSp53 implicated in 14-3-3 binding. Mutating these phosphorylation sites reverses 14-3-3-dependent inhibition of filopodia dynamics and cancer cell chemotaxis.

scholarly journals Mechanism of IRSp53 inhibition by 14-3-3

2018 ◽  
Author(s):  
David J. Kast ◽  
Roberto Dominguez
Keyword(s):  
Conformational Changes ◽  
Dendritic Spines ◽  
Mammalian Cells ◽  
Neuronal Development ◽  
Rho Gtpase ◽  
Phosphorylation Sites ◽  
Binding Studies ◽  
Bar Domain ◽  
Dependent Inhibition ◽  
Bicistronic Expression

AbstractFilopodia are precursors of dendritic spines and polarized cell migration. The I-BAR-domain protein IRSp53 is an essential regulator of filopodia dynamics that couples Rho-GTPase signaling to cytoskeleton and membrane remodeling, playing essential roles in neuronal development and cell motility. Here, we describe a mechanism whereby phosphorylation-dependent inhibition of IRSp53 by 14-3-3 counters membrane binding and activation by Cdc42 or downstream cytoskeletal effectors. Phosphoproteomics, quantitative binding studies and crystal structures show that 14-3-3 binds to two pairs of phosphorylation sites in IRSp53. Using bicistronic expression we obtained a heterodimer of IRSp53 in which only one subunit is phosphorylated, and show that each subunit of the IRSp53 dimer independently binds a 14-3-3 dimer. A FRET-sensor assay developed using natively phosphorylated and 14-3-3-binding competent IRSp53 purified from mammalian cells reveals opposite conformational changes in IRSp53 upon binding of activatory (Cdc42, Eps8) vs. inhibitory (14-3-3) inputs.

scholarly journals Long non-coding RNA ARHGAP5-AS1 inhibits migration of breast cancer cell via stabilizing SMAD7 protein

2021 ◽  
Author(s):  
Chen-Long Wang ◽  
Jing-Chi Li ◽  
Ci-Xiang Zhou ◽  
Cheng-Ning Ma ◽  
Di-Fei Wang ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Cell Migration ◽  
Cell Lines ◽  
Cancer Cell ◽  
Breast Cancer Cell ◽  
Rho Gtpase ◽  
Critical Role ◽  
Luciferase Reporter ◽  
Breast Cancer Cell Lines ◽  
Smad7 Protein

Abstract Purpose Tumor metastasis is the main cause of death from breast cancer patients and cell migration plays a critical role in cancer metastasis. Recent studies have shown long non-coding RNAs (lncRNAs) play an essential role in the initiation and progression of cancer. In the present study, the role of an LncRNA, Rho GTPase Activating Protein 5- Antisense 1 (ARHGAP5-AS1) in breast cancer was investigated. Methods RNA sequencing was performed to find out dysregulated LncRNAs in MDA-MB-231-LM2 cells. Transwell migration assays and F-actin staining were utilized to estimate cell migration ability. RNA pulldown assays and RNA immunoprecipitation were used to prove the interaction between ARHGAP5-AS1 and SMAD7. Western blot and immunofluorescence imaging were used to examine the protein levels. Dual luciferase reporter assays were performed to evaluate the activation of TGF-β signaling. Results We analyzed the RNA-seq data of MDA-MB-231 and its highly metastatic derivative MDA-MB-231-LM2 cell lines (referred to as LM2) and identified a novel lncRNA (NR_027263) named as ARHGAP5-AS1, which expression was significantly downregulated in LM2 cells. Further functional investigation showed ARHGAP5-AS1 could inhibit cell migration via suppression of stress fibers in breast cancer cell lines. Afterwards, SMAD7 was further identified to interact with ARHGAP5-AS1 by its PY motif and thus its ubiquitination and degradation was blocked due to reduced interaction with E3 ligase SMURF1 and SMURF2. Moreover, ARHGAP5-AS1 could inhibit TGF-β signaling pathway due to its inhibitory role on SMAD7. Conclusion ARHGAP5-AS1 inhibits breast cancer cell migration via stabilization of SMAD7 protein and could serve as a novel biomarker and a potential target for breast cancer in the future.

The atypical Rho GTPase RhoD is a regulator of actin cytoskeleton dynamics and directed cell migration

2017 ◽  
Vol 352 (2) ◽  
pp. 255-264 ◽  
Author(s):  
Magdalena Blom ◽  
Katarina Reis ◽  
Johan Heldin ◽  
Johan Kreuger ◽  
Pontus Aspenström
Keyword(s):  
Cell Migration ◽  
Actin Cytoskeleton ◽  
Rho Gtpase ◽  
Directed Cell Migration ◽  
Cytoskeleton Dynamics

scholarly journals The anticancer phytochemical rocaglamide inhibits Rho GTPase activity and cancer cell migration

Oncotarget ◽  
2016 ◽  
Vol 7 (32) ◽  
pp. 51908-51921 ◽  
Author(s):  
Michael S. Becker ◽  
Paul M. Müller ◽  
Jörg Bajorat ◽  
Anne Schroeder ◽  
Marco Giaisi ◽  
...  
Keyword(s):  
Cell Migration ◽  
Cancer Cell ◽  
Rho Gtpase ◽  
Cancer Cell Migration ◽  
Gtpase Activity

scholarly journals Rho GTPases and the emerging role of tunneling nanotubes in physiology and disease

2020 ◽  
Vol 319 (5) ◽  
pp. C877-C884
Author(s):  
Suli Zhang ◽  
Marcelo G. Kazanietz ◽  
Mariana Cooke
Keyword(s):  
Rho Gtpases ◽  
Cell Function ◽  
Rho Gtpase ◽  
Cell Communication ◽  
Nucleotide Exchange ◽  
Tunneling Nanotubes ◽  
Guanine Nucleotide Exchange ◽  
Physiological Processes ◽  
Membrane Protrusions ◽  
Intercellular Exchange

Tunneling nanotubes (TNTs) emerged as important specialized actin-rich membrane protrusions for cell-to-cell communication. These structures allow the intercellular exchange of material, such as ions, soluble proteins, receptors, vesicles and organelles, therefore exerting critical roles in normal cell function. Indeed, TNTs participate in a number of physiological processes, including embryogenesis, immune response, and osteoclastogenesis. TNTs have been also shown to contribute to the transmission of retroviruses (e.g., human immunodeficiency virus-1, HIV-1) and coronaviruses. As with other membrane protrusions, the involvement of Rho GTPases in the formation of these elongated structures is undisputable, although the mechanisms involved are not yet fully elucidated. The tight control of Rho GTPase function by guanine nucleotide exchange factors (GEFs) and GTPase-activating proteins (GAPs) strongly suggests that localized control of these Rho regulators may contribute to TNT assembly and disassembly. Deciphering the intricacies of the complex signaling mechanisms leading to actin reorganization and TNT development would reveal important information about their involvement in normal cellular physiology as well as unveil potential targets for disease management.

scholarly journals Three-dimensional Cancer Cell Migration Directed by Dual Mechanochemical Guidance

2021 ◽  
Author(s):  
Pedram Esfahani ◽  
Herbert Levine ◽  
Mrinmoy Mukherjee ◽  
Bo Sun
Keyword(s):  
Cell Migration ◽  
Cancer Cell ◽  
Breast Cancer Cells ◽  
Three Dimensional ◽  
Contact Guidance ◽  
Chemical Gradient ◽  
Cell Microenvironment ◽  
Directed Cell Migration ◽  
The Impact ◽  
Cell Mechanosensing

Directed cell migration guided by external cues plays a central role in many physiological and pathophysiological processes. The microenvironment of cells often simultaneously contains various cues and the motility response of cells to multiplexed guidance is poorly understood. Here we combine experiments and mathematical models to study the three-dimensional migration of breast cancer cells in the presence of both contact guidance and a chemoattractant gradient. We find that the chemotaxis of cells is complicated by the presence of contact guidance as the microstructure of extracellular matrix (ECM) vary spatially. In the presence of dual guidance, the impact of ECM alignment is determined externally by the coherence of ECM fibers, and internally by cell mechanosensing Rho/Rock pathways. When contact guidance is parallel to the chemical gradient, coherent ECM fibers significantly increase the efficiency of chemotaxis. When contact guidance is perpendicular to the chemical gradient, cells exploit the ECM disorder to locate paths for chemotaxis. Our results underscores the importance of fully characterizing the cancer cell microenvironment in order to better understand invasion and metastasis.

scholarly journals Actin dynamics in cell migration

2019 ◽  
Vol 63 (5) ◽  
pp. 483-495 ◽  
Author(s):  
Matthias Schaks ◽  
Grégory Giannone ◽  
Klemens Rottner
Keyword(s):  
Plasma Membrane ◽  
Cell Migration ◽  
Actin Filament ◽  
Rho Gtpases ◽  
Rho Gtpase ◽  
Actin Dynamics ◽  
Regulatory Complex ◽  
Membrane Protrusions ◽  
Filament Networks ◽  
Contractile Forces

Abstract Cell migration is an essential process, both in unicellular organisms such as amoeba and as individual or collective motility in highly developed multicellular organisms like mammals. It is controlled by a variety of activities combining protrusive and contractile forces, normally generated by actin filaments. Here, we summarize actin filament assembly and turnover processes, and how respective biochemical activities translate into different protrusion types engaged in migration. These actin-based plasma membrane protrusions include actin-related protein 2/3 complex-dependent structures such as lamellipodia and membrane ruffles, filopodia as well as plasma membrane blebs. We also address observed antagonisms between these protrusion types, and propose a model – also inspired by previous literature – in which a complex balance between specific Rho GTPase signaling pathways dictates the protrusion mechanism employed by cells. Furthermore, we revisit published work regarding the fascinating antagonism between Rac and Rho GTPases, and how this intricate signaling network can define cell behavior and modes of migration. Finally, we discuss how the assembly of actin filament networks can feed back onto their regulators, as exemplified for the lamellipodial factor WAVE regulatory complex, tightly controlling accumulation of this complex at specific subcellular locations as well as its turnover.

Engineering Tools for Studying Coordination Between Biochemical and Biomechanical Activities in Cell Migration

2011 ◽  
Author(s):  
Sungsoo Na
Keyword(s):  
Cell Migration ◽  
Rho Gtpases ◽  
Rho Gtpase ◽  
Resonance Energy Transfer ◽  
Focal Adhesions ◽  
Resonance Energy ◽  
Leading Edge ◽  
Dynamic Feedback ◽  
Chemical Signaling ◽  
Directed Cell Migration

Cell migration is achieved by the dynamic feedback interactions between traction forces generated by the cell and exerted onto the underlying extracellular matrix (ECM), and intracellular mechano-chemical signaling pathways, e.g., Rho GTPase (RhoA, Rac1, and Cdc42) activities [1,2,3]. These components are differentially distributed within a cell, and thus the coordination between tractions and mechanotransduction (i.e, RhoA and Rac1 activities) must be implemented at a precise spatial and temporal order to achieve optimized, directed cell migration [4,5]. Recent studies have shown that focal adhesions at the leading edge exert strong tractions [6], and these traction sites are co-localized with focal adhesion sites [7]. Further, by using the fluorescence resonance energy transfer (FRET) technology coupled with genetically encoded biosensors, researchers reported that Rho GTPases, such as RhoA [8], Rac1 [9], and Cdc42 [10] are maximally activated at the leading edge, suggesting the leading edge of the cell as its common functional site for Rho GTPase activities. All these works, however, were done separately, and the relationship between tractions and mechanotransduction during cell migration has not been demonstrated directly because of the difficulty in simultaneously recording tractions and mechanotransduction in migrating cells, precluding direct comparison between these results. Furthermore, these studies have been conducted by monitoring cells on glass coverslips, the stiffness of which is ∼ 65 giga pascal (GPa), at least three to six order higher than the physiological range of ECM stiffness. Although it is increasingly accepted that ECM stiffness influences cell migration, it is not known exactly how physiologically relevant ECM stiffness (order of kPa range) affects the dynamics of RhoA and Rac1 activities. For a complete understanding of the mechanism of mechano-chemical signaling in the context of cell migration, the dynamics and interplay between biomechanical (e.g., tractions) and biochemical (e.g., Rho GTPase) activities should be visualized within the physiologically relevant range of ECM stiffness.

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