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

2017 ◽  
Vol 28 (16) ◽  
pp. 2159-2169 ◽  
Author(s):  
Max-Hinderk Schuler ◽  
Agnieszka Lewandowska ◽  
Giuseppe Di Caprio ◽  
Wesley Skillern ◽  
Srigokul Upadhyayula ◽  
...  

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.

2021 ◽  
Author(s):  
Erik S Linklater ◽  
Emily Duncan ◽  
Ke Jun Han ◽  
Algirdas Kaupinis ◽  
Mindaugas Valius ◽  
...  

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.


2011 ◽  
Vol 193 (7) ◽  
pp. 1289-1303 ◽  
Author(s):  
Violaine D. Delorme-Walker ◽  
Jeffrey R. Peterson ◽  
Jonathan Chernoff ◽  
Clare M. Waterman ◽  
Gaudenz Danuser ◽  
...  

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.


2021 ◽  
Vol 220 (7) ◽  
Author(s):  
Erik S. Linklater ◽  
Emily D. Duncan ◽  
Ke-Jun Han ◽  
Algirdas Kaupinis ◽  
Mindaugas Valius ◽  
...  

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.


2004 ◽  
Vol 165 (3) ◽  
pp. 421-432 ◽  
Author(s):  
Yi Hsing Lin ◽  
Zee-Yong Park ◽  
Dayin Lin ◽  
Anar A. Brahmbhatt ◽  
Marie-Christine Rio ◽  
...  

Large-scale proteomic and functional analysis of isolated pseudopodia revealed the Lim, actin, and SH3 domain protein (Lasp-1) as a novel protein necessary for cell migration, but not adhesion to, the extracellular matrix (ECM). Lasp-1 is a ubiquitously expressed actin-binding protein with a unique domain configuration containing SH3 and LIM domains, and is overexpressed in 8–12% of human breast cancers. We find that stimulation of nonmotile and quiescent cells with growth factors or ECM proteins facilitates Lasp-1 relocalization from the cell periphery to the leading edge of the pseudopodium, where it associates with nascent focal complexes and areas of actin polymerization. Interestingly, although Lasp-1 dynamics in migratory cells occur independently of c-Abl kinase activity and tyrosine phosphorylation, c-Abl activation by apoptotic agents specifically promotes phosphorylation of Lasp-1 at tyrosine 171, which is associated with the loss of Lasp-1 localization to focal adhesions and induction of cell death. Thus, Lasp-1 is a dynamic focal adhesion protein necessary for cell migration and survival in response to growth factors and ECM proteins.


2006 ◽  
Vol 176 (1) ◽  
pp. 35-42 ◽  
Author(s):  
Erik Sahai ◽  
Raquel Garcia-Medina ◽  
Jacques Pouysségur ◽  
Emmanuel Vial

Rho GTPases participate in various cellular processes, including normal and tumor cell migration. It has been reported that RhoA is targeted for degradation at the leading edge of migrating cells by the E3 ubiquitin ligase Smurf1, and that this is required for the formation of protrusions. We report that Smurf1-dependent RhoA degradation in tumor cells results in the down-regulation of Rho kinase (ROCK) activity and myosin light chain 2 (MLC2) phosphorylation at the cell periphery. The localized inhibition of contractile forces is necessary for the formation of lamellipodia and for tumor cell motility in 2D tissue culture assays. In 3D invasion assays, and in in vivo tumor cell migration, the inhibition of Smurf1 induces a mesenchymal–amoeboid–like transition that is associated with a more invasive phenotype. Our results suggest that Smurf1 is a pivotal regulator of tumor cell movement through its regulation of RhoA signaling.


2005 ◽  
Vol 16 (1) ◽  
pp. 84-96 ◽  
Author(s):  
Michele A. Wozniak ◽  
Lina Kwong ◽  
David Chodniewicz ◽  
Richard L. Klemke ◽  
Patricia J. Keely

Although it is known that the spatial coordination of Rac and Rho activity is essential for cell migration, the molecular mechanisms regulating these GTPases during migration are unknown. We found that the expression of constitutively activated R-Ras (38V) blocked membrane protrusion and random migration. In contrast, expression of dominant negative R-Ras (41A) enhanced migrational persistence and membrane protrusion. Endogenous R-Ras is necessary for cell migration, as cells that were transfected with siRNA for R-Ras did not migrate. Expression of R-Ras (38V) decreased Rac activity and increased Rho activity around the entire cell periphery, whereas expression of dominant negative R-Ras (41A) showed the converse, suggesting that R-Ras can spatially activate Rho and inactivate Rac. Consistent with this role, endogenous R-Ras localized and was preferentially activated at the leading edge of migratory cells in response to adhesion. The effects of R-Ras on cell migration are mediated by PI3-Kinase, as an effector mutant that uncouples PI3-Kinase binding from R-Ras (38V) rescued migration. From these data, we hypothesize that R-Ras plays a key role in cell migration by locally regulating the switch from Rac to Rho activity after membrane protrusion and adhesion.


2014 ◽  
Vol 306 (8) ◽  
pp. C753-C761 ◽  
Author(s):  
Rachel A. Cleary ◽  
Ruping Wang ◽  
Omar Waqar ◽  
Harold A. Singer ◽  
Dale D. Tang

c-Abl is a nonreceptor protein tyrosine kinase that has a role in regulating smooth muscle cell proliferation and contraction. The role of c-Abl in smooth muscle cell migration has not been investigated. In the present study, c-Abl was found in the leading edge of smooth muscle cells. Knockdown of c-Abl by RNA interference attenuated smooth muscle cell motility as evidenced by time-lapse microscopy. Furthermore, the actin-associated proteins cortactin and profilin-1 (Pfn-1) have been implicated in cell migration. In this study, cell adhesion induced cortactin phosphorylation at Tyr-421, an indication of cortactin activation. Phospho-cortactin and Pfn-1 were also found in the cell edge. Pfn-1 directly interacted with cortactin in vitro. Silencing of c-Abl attenuated adhesion-induced cortactin phosphorylation and Pfn-1 localization in the cell edge. To assess the role of cortactin/Pfn-1 coupling, we developed a cell-permeable peptide. Treatment with the peptide inhibited the interaction of cortactin with Pfn-1 without affecting cortactin phosphorylation. Moreover, treatment with the peptide impaired the recruitment of Pfn-1 to the leading edge and cell migration. Finally, β1-integrin was required for the recruitment of c-Abl to the cell edge. Inhibition of actin dynamics impaired the spatial distribution of c-Abl. These results suggest that β1-integrin may recruit c-Abl to the leading cell edge, which may regulate cortactin phosphorylation in response to cell adhesion. Phosphorylated cortactin may facilitate the recruitment of Pfn-1 to the cell edge, which promotes localized actin polymerization, leading edge formation, and cell movement. Conversely, actin dynamics may strengthen the recruitment of c-Abl to the leading edge.


2007 ◽  
Vol 18 (10) ◽  
pp. 3860-3872 ◽  
Author(s):  
Justin G. Peacock ◽  
Ann L. Miller ◽  
William D. Bradley ◽  
Olga C. Rodriguez ◽  
Donna J. Webb ◽  
...  

In migrating cells, actin polymerization promotes protrusion of the leading edge, whereas actomyosin contractility powers net cell body translocation. Although they promote F-actin–dependent protrusions of the cell periphery upon adhesion to fibronectin (FN), Abl family kinases inhibit cell migration on FN. We provide evidence here that the Abl-related gene (Arg/Abl2) kinase inhibits fibroblast migration by attenuating actomyosin contractility and regulating focal adhesion dynamics. arg−/− fibroblasts migrate at faster average speeds than wild-type (wt) cells, whereas Arg re-expression in these cells slows migration. Surprisingly, the faster migrating arg−/− fibroblasts have more prominent F-actin stress fibers and focal adhesions and exhibit increased actomyosin contractility relative to wt cells. Interestingly, Arg requires distinct functional domains to inhibit focal adhesions and actomyosin contractility. The kinase domain–containing Arg N-terminal half can act through the RhoA inhibitor p190RhoGAP to attenuate stress fiber formation and cell contractility. However, Arg requires both its kinase activity and its cytoskeleton-binding C-terminal half to fully inhibit focal adhesions. Although focal adhesions do not turn over efficiently in the trailing edge of arg−/− cells, the increased contractility of arg−/− cells tears the adhesions from the substrate, allowing for the faster migration observed in these cells. Together, our data strongly suggest that Arg inhibits cell migration by restricting actomyosin contractility and regulating its coupling to the substrate through focal adhesions.


2009 ◽  
Vol 296 (3) ◽  
pp. C414-C421 ◽  
Author(s):  
Shannon M. Gallagher ◽  
John J. Castorino ◽  
Nancy J. Philp

Monocarboxylate transporter (MCT) 4 is a heteromeric proton-coupled lactate transporter that is noncovalently linked to the extracellular matrix metalloproteinase inducer CD147 and is typically expressed in glycolytic tissues. There is increasing evidence to suggest that ion transporters are part of macromolecular complexes involved in regulating β1-integrin adhesion and cell movement. In the present study we examined whether MCTs play a role in cell migration through their interaction with β1-integrin. Using reciprocal coimmunoprecipitation assays, we found that β1-integrin selectively associated with MCT4 in ARPE-19 and MDCK cells, two epithelial cell lines that express both MCT1 and MCT4. In polarized monolayers of ARPE-19 cells, MCT4 and β1-integrin colocalized to the basolateral membrane, while both proteins were found in the leading edge lamellapodia of migrating cells. In scratch-wound assays, MCT4 knockdown slowed migration and increased focal adhesion size. In contrast, silencing MCT1 did not alter the rate of cell migration or focal adhesion size. Taken together, our findings suggest that the specific interaction of MCT4 with β1-integrin may regulate cell migration through modulation of focal adhesions.


2014 ◽  
Vol 25 (5) ◽  
pp. 658-668 ◽  
Author(s):  
Pascale Daou ◽  
Salma Hasan ◽  
Dennis Breitsprecher ◽  
Emilie Baudelet ◽  
Luc Camoin ◽  
...  

Formins constitute a large family of proteins that regulate the dynamics and organization of both the actin and microtubule cytoskeletons. Previously we showed that the formin mDia1 helps tether microtubules at the cell cortex, acting downstream of the ErbB2 receptor tyrosine kinase. Here we further study the contributions of mDia1 and its two most closely related formins, mDia2 and mDia3, to cortical microtubule capture and ErbB2-dependent breast carcinoma cell migration. We find that depletion of each of these three formins strongly disrupts chemotaxis without significantly affecting actin-based structures. Further, all three formins are required for formation of cortical microtubules in a nonredundant manner, and formin proteins defective in actin polymerization remain active for microtubule capture. Using affinity purification and mass spectrometry analysis, we identify differential binding partners of the formin-homology domain 2 (FH2) of mDia1, mDia2, and mDia3, which may explain their nonredundant roles in microtubule capture. The FH2 domain of mDia1 specifically interacts with Rab6-interacting protein 2 (Rab6IP2). Further, mDia1 is required for cortical localization of Rab6IP2, and concomitant depletion of Rab6IP2 and IQGAP1 severely disrupts cortical capture of microtubules, demonstrating the coinvolvement of mDia1, IQGAP1, and Rab6IP2 in microtubule tethering at the leading edge.


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