Faculty Opinions recommendation of Pak1 regulates focal adhesion strength, myosin IIA distribution, and actin dynamics to optimize cell migration.

Cell motility requires the spatial and temporal coordination of forces in the actomyosin cytoskeleton with extracellular adhesion. The biochemical mechanism that coordinates filamentous actin (F-actin) assembly, myosin contractility, adhesion dynamics, and motility to maintain the balance between adhesion and contraction remains unknown. In this paper, we show that p21-activated kinases (Paks), downstream effectors of the small guanosine triphosphatases Rac and Cdc42, biochemically couple leading-edge actin dynamics to focal adhesion (FA) dynamics. Quantitative live cell microscopy assays revealed that the inhibition of Paks abolished F-actin flow in the lamella, displaced myosin IIA from the cell edge, and decreased FA turnover. We show that, by controlling the dynamics of these three systems, Paks regulate the protrusive activity and migration of epithelial cells. Furthermore, we found that expressing Pak1 was sufficient to overcome the inhibitory effects of excess adhesion strength on cell motility. These findings establish Paks as critical molecules coordinating cytoskeletal systems for efficient cell migration.

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Rab40/Cullin5 complex regulates EPLIN and actin cytoskeleton dynamics during cell migration and invasion

10.1101/2021.04.01.438077 ◽

2021 ◽

Author(s):

Erik S Linklater ◽

Emily Duncan ◽

Ke Jun Han ◽

Algirdas Kaupinis ◽

Mindaugas Valius ◽

...

Keyword(s):

Cell Migration ◽

Actin Cytoskeleton ◽

Focal Adhesion ◽

Focal Adhesions ◽

Leading Edge ◽

Stress Fibers ◽

Actin Dynamics ◽

Migration And Invasion ◽

Matrix Remodeling ◽

Cell Migration And Invasion

Rab40b is a SOCS box containing protein that regulates the secretion of MMPs to facilitate extracellular matrix remodeling during cell migration. Here we show that Rab40b interacts with Cullin5 via the Rab40b SOCS domain. We demonstrate that loss of Rab40b/Cullin5 binding decreases cell motility and invasive potential, and show that defective cell migration and invasion stem from alteration to the actin cytoskeleton, leading to decreased invadopodia formation, decreased actin dynamics at the leading edge, and an increase in stress fibers. We also show that these stress fibers anchor at less dynamic, more stable focal adhesions. Mechanistically, changes in the cytoskeleton and focal adhesion dynamics are mediated in part by EPLIN, which we demonstrate to be a binding partner of Rab40b and a target for Rab40b/Cullin5 dependent localized ubiquitylation and degradation. Thus, we propose a model where the Rab40b/Cullin5 dependent ubiquitylation regulates EPLIN localization to promote cell migration and invasion by altering focal adhesion and cytoskeletal dynamics.

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S100P Dissociates Myosin IIA Filaments and Focal Adhesion Sites to Reduce Cell Adhesion and Enhance Cell Migration

Journal of Biological Chemistry ◽

10.1074/jbc.m112.349787 ◽

2012 ◽

Vol 287 (19) ◽

pp. 15330-15344 ◽

Cited By ~ 37

Author(s):

Min Du ◽

Guozheng Wang ◽

Thamir M. Ismail ◽

Stephane Gross ◽

David G. Fernig ◽

...

Keyword(s):

Cell Migration ◽

Cell Adhesion ◽

Focal Adhesion ◽

Adhesion Sites ◽

Myosin Iia

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Altered Actin Dynamics in Cell Migration of GNE Mutant Cells

Frontiers in Cell and Developmental Biology ◽

10.3389/fcell.2021.603742 ◽

2021 ◽

Vol 9 ◽

Author(s):

Shamulailatpam Shreedarshanee Devi ◽

Rashmi Yadav ◽

Ranjana Arya

Keyword(s):

Signal Transduction ◽

Cell Migration ◽

Sialic Acid ◽

Focal Adhesion ◽

Actin Polymerization ◽

Cytoskeletal Proteins ◽

Confocal Imaging ◽

Actin Dynamics ◽

Focal Adhesion Complex ◽

Adhesion Complex

Cell migration is an essential cellular process that requires coordination of cytoskeletal dynamics, reorganization, and signal transduction. The actin cytoskeleton is central in maintaining the cellular structure as well as regulating the mechanisms of cell motility. Glycosylation, particularly sialylation of cell surface proteins like integrins, regulates signal transduction from the extracellular matrix to the cytoskeletal network. The activation of integrin by extracellular cues leads to recruitment of different focal adhesion complex proteins (Src, FAK, paxillin, etc.) and activates the signal including Rho GTPases for the regulation of actin assembly and disassembly. During cell migration, the assembly and disassembly of actin filament provides the essential force for the cell to move. Abnormal sialylation can lead to actin signaling dysfunction leading to aberrant cell migration, one of the main characteristics of cancer and myopathies. In the present study, we have reported altered F-actin to G-actin ratios in GNE mutated cells. These cells exhibit pathologically relevant mutations of GNE (UDP N-acetylneuraminic 2-epimerase/N-acetylmannosamine kinase), a key sialic acid biosynthetic enzyme. It was found that GNE neither affects the actin polymerization nor binds directly to actin. However, mutation in GNE resulted in increased binding of α-actinin to actin filaments. Further, through confocal imaging, GNE was found to be localized in focal adhesion complex along with paxillin. We further elucidated that mutation in GNE resulted in upregulation of RhoA protein and Cofilin activity is downregulated, which could be rescued with Rhosin and chlorogenic acid, respectively. Lastly, mutant in GNE reduced cell migration as implicated from wound healing assay. Our study indicates that molecules altering Cofilin function could significantly revert the cell migration defect due to GNE mutation in sialic acid-deficient cells. We propose cytoskeletal proteins to be alternate drug targets for disorders associated with GNE such as GNE myopathy.

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Miro1-mediated mitochondrial positioning shapes intracellular energy gradients required for cell migration

Molecular Biology of the Cell ◽

10.1091/mbc.e16-10-0741 ◽

2017 ◽

Vol 28 (16) ◽

pp. 2159-2169 ◽

Cited By ~ 52

Author(s):

Max-Hinderk Schuler ◽

Agnieszka Lewandowska ◽

Giuseppe Di Caprio ◽

Wesley Skillern ◽

Srigokul Upadhyayula ◽

...

Keyword(s):

Cell Migration ◽

Focal Adhesion ◽

Energy Production ◽

Rho Gtpase ◽

Leading Edge ◽

Dorsal Surface ◽

Actin Dynamics ◽

Cell Cortex ◽

Cell Periphery ◽

Intracellular Energy

It has long been postulated, although never directly demonstrated, that mitochondria are strategically positioned in the cytoplasm to meet local requirements for energy production. Here we show that positioning of mitochondria in mouse embryonic fibroblasts (MEFs) determines the shape of intracellular energy gradients in living cells. Specifically, the ratio of ATP to ADP was highest at perinuclear areas of dense mitochondria and gradually decreased as more-peripheral sites were approached. Furthermore, the majority of mitochondria were positioned at the ventral surface of the cell, correlating with high ATP:ADP ratios close to the ventral membrane, which rapidly decreased toward the dorsal surface. We used cells deficient for the mitochondrial Rho-GTPase 1 (Miro1), an essential mediator of microtubule-based mitochondrial motility, to study how changes in mitochondrial positioning affect cytoplasmic energy distribution and cell migration, an energy-expensive process. The mitochondrial network in Miro1−/− MEFs was restricted to the perinuclear area, with few mitochondria present at the cell periphery. This change in mitochondrial distribution dramatically reduced the ratio of ATP to ADP at the cell cortex and disrupted events essential for cell movement, including actin dynamics, lamellipodia protrusion, and membrane ruffling. Cell adhesion status was also affected by changes in mitochondrial positioning; focal adhesion assembly and stability was decreased in Miro1−/−MEFs compared with Miro1+/+ MEFs. Consequently Miro1−/− MEFs migrated slower than control cells during both collective and single-cell migration. These data establish that Miro1-mediated mitochondrial positioning at the leading edge provides localized energy production that promotes cell migration by supporting membrane protrusion and focal adhesion stability.

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Rab40–Cullin5 complex regulates EPLIN and actin cytoskeleton dynamics during cell migration

The Journal of Cell Biology ◽

10.1083/jcb.202008060 ◽

2021 ◽

Vol 220 (7) ◽

Author(s):

Erik S. Linklater ◽

Emily D. Duncan ◽

Ke-Jun Han ◽

Algirdas Kaupinis ◽

Mindaugas Valius ◽

...

Keyword(s):

Cell Migration ◽

Actin Cytoskeleton ◽

Focal Adhesion ◽

Focal Adhesions ◽

Leading Edge ◽

Stress Fibers ◽

Actin Dynamics ◽

Migration And Invasion ◽

Matrix Remodeling ◽

Cell Migration And Invasion

Rab40b is a SOCS box–containing protein that regulates the secretion of MMPs to facilitate extracellular matrix remodeling during cell migration. Here, we show that Rab40b interacts with Cullin5 via the Rab40b SOCS domain. We demonstrate that loss of Rab40b–Cullin5 binding decreases cell motility and invasive potential and show that defective cell migration and invasion stem from alteration to the actin cytoskeleton, leading to decreased invadopodia formation, decreased actin dynamics at the leading edge, and an increase in stress fibers. We also show that these stress fibers anchor at less dynamic, more stable focal adhesions. Mechanistically, changes in the cytoskeleton and focal adhesion dynamics are mediated in part by EPLIN, which we demonstrate to be a binding partner of Rab40b and a target for Rab40b–Cullin5-dependent localized ubiquitylation and degradation. Thus, we propose a model where Rab40b–Cullin5-dependent ubiquitylation regulates EPLIN localization to promote cell migration and invasion by altering focal adhesion and cytoskeletal dynamics.

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