Faculty Opinions recommendation of The role of Ppt/Wnt5 in regulating cell shape and movement during zebrafish gastrulation.

Author(s):  
Marek Mlodzik
Keyword(s):  
2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Cécile Gaston ◽  
Simon De Beco ◽  
Bryant Doss ◽  
Meng Pan ◽  
Estelle Gauquelin ◽  
...  

AbstractAt the basis of cell shape and behavior, the organization of actomyosin and its ability to generate forces are widely studied. However, the precise regulation of this contractile network in space and time is unclear. Here, we study the role of the epithelial-specific protein EpCAM, a contractility modulator, in cell shape and motility. We show that EpCAM is required for stress fiber generation and front-rear polarity acquisition at the single cell level. In fact, EpCAM participates in the remodeling of a transient zone of active RhoA at the cortex of spreading epithelial cells. EpCAM and RhoA route together through the Rab35/EHD1 fast recycling pathway. This endosomal pathway spatially organizes GTP-RhoA to fine tune the activity of actomyosin resulting in polarized cell shape and development of intracellular stiffness and traction forces. Impairment of GTP-RhoA endosomal trafficking either by silencing EpCAM or by expressing Rab35/EHD1 mutants prevents proper myosin-II activity, stress fiber formation and ultimately cell polarization. Collectively, this work shows that the coupling between co-trafficking of EpCAM and RhoA, and actomyosin rearrangement is pivotal for cell spreading, and advances our understanding of how biochemical and mechanical properties promote cell plasticity.


2021 ◽  
pp. 1-7
Author(s):  
Dongjie Zhou ◽  
Zheng-Wen Nie ◽  
Xiang-Shun Cui

The cytoskeleton plays an orchestrating role in polarized cell growth. Microtubules (MTs) not only play critical roles in chromosome alignment and segregation but also control cell shape, division, and motility. A member of the plus-end tracking proteins, end-binding protein 1 (EB1), regulates MT dynamics and plays vital roles in maintaining spindle symmetry and chromosome alignment during mitosis. However, the role of EB1 in mouse oocyte meiosis remains unknown. Here, we examined the localization patterns and expression levels of EB1 at different stages. EB1 protein level was found to be stable during meiosis. EB1 mainly localized along the spindle and had a similar localization pattern as that of α-tubulin. The EB1 protein was degraded with a Trim-Away method, and the results were further confirmed with western blotting and immunofluorescence. At 12 h of culture after EB1 knockdown (KD), a reduced number of mature MII oocytes were observed. EB1 KD led to spindle disorganization, chromosome misalignment, and missegregation; β-catenin protein binds to actin via the adherens junctional complex, which was significantly reduced in the EB1 KD oocytes. Collectively, we propose that the impairment of EB1 function manipulates spindle formation, thereby promoting chromosomal loss, which is expected to fuel aneuploidy and possibly fertilization failure.


2010 ◽  
Vol 191 (2) ◽  
pp. 233-236 ◽  
Author(s):  
Jagesh V. Shah

In this issue, Pitaval et al. (2010. J. Cell Biol. doi:10.1083/jcb.201004003) demonstrate that cell geometry can regulate the elaboration of a primary cilium. Their findings and approaches are part of a historical line of inquiry investigating the role of cell shape in intracellular organization and cellular function.


2008 ◽  
Vol 182 (2) ◽  
pp. 221-223 ◽  
Author(s):  
Iiro Taneli Helenius ◽  
Greg J. Beitel

Tubular organs are essential for life, but lumen formation in nonepithelial tissues such as the vascular system or heart is poorly understood. Two studies in this issue (Medioni, C., M. Astier, M. Zmojdzian, K. Jagla, and M. Sémériva. 2008. J. Cell Biol. 182:249–261; Santiago-Martínez, E., N.H. Soplop, R. Patel, and S.G. Kramer. 2008. J. Cell Biol. 182:241–248) reveal unexpected roles for the Slit–Robo signaling system during Drosophila melanogaster heart morphogenesis. In cardioblasts, Slit and Robo modulate the cell shape changes and domains of E-cadherin–based adhesion that drive lumen formation. Furthermore, in contrast to the well-known paracrine role of Slit and Robo in guiding cell migrations, here Slit and Robo may act by autocrine signaling. In addition, the two groups demonstrate that heart lumen formation is even more distinct from typical epithelial tubulogenesis mechanisms because the heart lumen is bounded by membrane surfaces that have basal rather than apical attributes. As the D. melanogaster cardioblasts are thought to have significant evolutionary similarity to vertebrate endothelial and cardiac lineages, these findings are likely to provide insights into mechanisms of vertebrate heart and vascular morphogenesis.


1985 ◽  
Vol 74 (1) ◽  
pp. 267-282
Author(s):  
L.V. Domnina ◽  
J.A. Rovensky ◽  
J.M. Vasiliev ◽  
I.M. Gelfand

The role of microtubules in the spreading of cells from the liver-derived IAR2 rat cell line was studied. Cells in the control medium seeded on a flat isotropic glass surface rapidly spread to form discoid shapes. Spreading in colcemid-containing medium was disorganized and delayed; partial reversal of spreading was observed. Nevertheless, even in the presence of colcemid the cells finally spread to discoid flattened shapes. IAR2 cells in medium without colcemid spread not to discoid but to elongated shapes under three different sets of conditions: (1) when the cells were forced to spread on narrow strips of adhesive glass surface between two non-adhesive lipid films; (2) when the cells spread on the poorly adhesive surface of poly(HEMA)-covered glass; (3) when the cells spread on the usual glass surfaces in medium containing cytochalasin D. Addition of colcemid to the media reversed the polarized spreading under the first two conditions; colcemid did not reverse the formation of the elongated cell shape acquired by the cells spreading in cytochalasin-containing medium. Effects of microtubule-destroying drugs on the spreading of epithelial and fibroblast cells are compared and discussed. It is suggested that microtubules are essential for the stabilization of the spread state of those attached cytoplasmic processes and lamellae that do not have numerous and stable-cell substratum contacts, e.g. the processes formed at the early stages of spreading or the elongated processes of polarized cells. Possibly, microtubules stabilize the non-contracted state of the actin cytoskeleton in these processes.


2015 ◽  
Vol 208 (4) ◽  
pp. 443-455 ◽  
Author(s):  
Heath E. Johnson ◽  
Samantha J. King ◽  
Sreeja B. Asokan ◽  
Jeremy D. Rotty ◽  
James E. Bear ◽  
...  

Mesenchymal cells such as fibroblasts are weakly polarized and reorient directionality by a lamellipodial branching mechanism that is stabilized by phosphoinositide 3-kinase (PI3K) signaling. However, the mechanisms by which new lamellipodia are initiated and directed are unknown. Using total internal reflection fluorescence microscopy to monitor cytoskeletal and signaling dynamics in migrating cells, we show that peripheral F-actin bundles/filopodia containing fascin-1 serve as templates for formation and orientation of lamellipodia. Accordingly, modulation of fascin-1 expression tunes cell shape, quantified as the number of morphological extensions. Ratiometric imaging reveals that F-actin bundles/filopodia play both structural and signaling roles, as they prime the activation of PI3K signaling mediated by integrins and focal adhesion kinase. Depletion of fascin-1 ablated fibroblast haptotaxis on fibronectin but not platelet-derived growth factor chemotaxis. Based on these findings, we conceptualize haptotactic sensing as an exploration, with F-actin bundles directing and lamellipodia propagating the process and with signaling mediated by adhesions playing the role of integrator.


2009 ◽  
Vol 329 (1-2) ◽  
pp. 175-179 ◽  
Author(s):  
Masaaki Miyamoto ◽  
Shinki Iwashita ◽  
Satomi Yamaguchi ◽  
Yoshitaka Ono
Keyword(s):  

2020 ◽  
Vol 71 (18) ◽  
pp. 5414-5424
Author(s):  
Yoshihisa Yoshimi ◽  
Katsuya Hara ◽  
Mami Yoshimura ◽  
Nobukazu Tanaka ◽  
Takumi Higaki ◽  
...  

Abstract Arabinogalactan-proteins (AGPs) are a family of plant extracellular proteoglycans implicated in many physiological events. AGP is decorated with type II arabinogalactans (AGs) consisting of a β-1,3-galactan backbone and β-1,6-galactan side chains, to which other sugars are attached. Based on the fact that a type II AG-specific inhibitor, β-Yariv reagent, perturbs growth and development, it has been proposed that type II AGs participate in the regulation of cell shape and tissue organization. However, the mechanisms by which type II AGs participate have not yet been established. Here, we describe a novel system that causes specific degradation of type II AGs in Arabidopsis, by which a gene encoding a fungal exo-β-1,3-galactanase that specifically hydrolyzes β-1,3-galactan backbones of type II AGs is expressed under the control of a dexamethasone-inducible promoter. Dexamethasone treatment increased the galactanase activity, leading to a decrease in Yariv reagent-reactive AGPs in transgenic Arabidopsis. We detected the typical oligosaccharides released from type II AGs by Il3GAL in the soluble fraction, demonstrating that Il3GAL acted on type II AG in the transgenic plants. Additionally, this resulted in severe tissue disorganization in the hypocotyl and cotyledons, suggesting that the degradation of type II AGs affected the regulation of cell shape.


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