scholarly journals Caenorhabditis elegans Flamingo FMI-1 controls dendrite self-avoidance through F-actin assembly

Development ◽  
2020 ◽  
Vol 147 (14) ◽  
pp. dev179168
Author(s):  
Hao-Wei Hsu ◽  
Chien-Po Liao ◽  
Yueh-Chen Chiang ◽  
Ru-Ting Syu ◽  
Chun-Liang Pan
Keyword(s):  
Caenorhabditis Elegans ◽  
Genetic Analysis ◽  
Actin Cytoskeleton ◽  
Adhesion Molecules ◽  
Cell Polarity ◽  
Planar Cell Polarity ◽  
Molecular Mechanisms ◽  
Protein Complexes ◽  
Actin Assembly ◽  
Proper Functioning

ABSTRACTSelf-avoidance is a conserved mechanism that prevents crossover between sister dendrites from the same neuron, ensuring proper functioning of the neuronal circuits. Several adhesion molecules are known to be important for dendrite self-avoidance, but the underlying molecular mechanisms are incompletely defined. Here, we show that FMI-1/Flamingo, an atypical cadherin, is required autonomously for self-avoidance in the multidendritic PVD neuron of Caenorhabditis elegans. The fmi-1 mutant shows increased crossover between sister PVD dendrites. Our genetic analysis suggests that FMI-1 promotes transient F-actin assembly at the tips of contacting sister dendrites to facilitate their efficient retraction during self-avoidance events, probably by interacting with WSP-1/N-WASP. Mutations of vang-1, which encodes the planar cell polarity protein Vangl2 previously shown to inhibit F-actin assembly, suppress self-avoidance defects of the fmi-1 mutant. FMI-1 downregulates VANG-1 levels probably through forming protein complexes. Our study identifies molecular links between Flamingo and the F-actin cytoskeleton that facilitate efficient dendrite self-avoidance.

scholarly journals Celsr1 and CAMSAP3 differently regulate intercellular and intracellular cilia orientation in oviduct multiciliated cells

2020 ◽  
Author(s):  
Fumiko Matsukawa Usami ◽  
Masaki Arata ◽  
Dongbo Shi ◽  
Sanae Oka ◽  
Yoko Higuchi ◽  
...  
Keyword(s):  
Cell Polarity ◽  
Planar Cell Polarity ◽  
Molecular Mechanisms ◽  
The Other ◽  
Basal Bodies ◽  
Generating Functional ◽  
Tissue Polarity ◽  
Other Hand ◽  
Multiciliated Cells ◽  
Polarity Regulation

SummaryThe molecular mechanisms by which cilia orientation is coordinated within and between multiciliated cells (MCCs) is not fully understood. By observing the orientation of basal bodies (BB) in MCCs of mouse oviducts, here, we show that Celsr1, a planar cell polarity (PCP) factor involved in tissue polarity regulation, is dispensable for determining BB orientation in individual cells, whereas CAMSAP3, a microtubule minus-end regulator, is critical for this process but not for PCP. MCCs exhibit a characteristic BB orientation and microtubule gradient along the tissue axis, and these intracellular polarities were maintained in the cells lacking Celsr1, although the intercellular coordination of the polarities was partly disrupted. On the other hand, CAMSAP3 regulated the assembly of microtubules interconnecting BBs by localizing at the BBs, and its mutation led to disruption of intracellular coordination of BB orientation, but not affecting PCP factor localization. Thus, both Celsr1 and CAMSAP3 are responsible for BB orientation but in distinct ways; and therefore, their cooperation should be critical for generating functional multiciliated tissues.

scholarly journals Mechanochemical Control of Symmetry Breaking in the Caenorhabditis elegans Zygote

2021 ◽  
Vol 8 ◽  
Author(s):  
Wan Jun Gan ◽  
Fumio Motegi
Keyword(s):  
Caenorhabditis Elegans ◽  
Symmetry Breaking ◽  
Actin Cytoskeleton ◽  
Cell Polarity ◽  
Break Symmetry ◽  
Cell Cortex ◽  
Aurora A Kinase ◽  
Advective Flow ◽  
Polar State ◽  
Cellular Components

Cell polarity is the asymmetric organization of cellular components along defined axes. A key requirement for polarization is the ability of the cell to break symmetry and achieve a spatially biased organization. Despite different triggering cues in various systems, symmetry breaking (SB) usually relies on mechanochemical modulation of the actin cytoskeleton, which allows for advected movement and reorganization of cellular components. Here, the mechanisms underlying SB in Caenorhabditis elegans zygote, one of the most popular models to study cell polarity, are reviewed. A zygote initiates SB through the centrosome, which modulates mechanics of the cell cortex to establish advective flow of cortical proteins including the actin cytoskeleton and partitioning defective (PAR) proteins. The chemical signaling underlying centrosomal control of the Aurora A kinase–mediated cascade to convert the organization of the contractile actomyosin network from an apolar to polar state is also discussed.

scholarly journals Tissue Organization by Cadherin Adhesion Molecules: Dynamic Molecular and Cellular Mechanisms of Morphogenetic Regulation

2011 ◽  
Vol 91 (2) ◽  
pp. 691-731 ◽  
Author(s):  
Carien M. Niessen ◽  
Deborah Leckband ◽  
Alpha S. Yap
Keyword(s):  
Cell Surface ◽  
Actin Cytoskeleton ◽  
Cell Signaling ◽  
Adhesion Molecules ◽  
Molecular Basis ◽  
Molecular Mechanisms ◽  
Comprehensive Understanding ◽  
Cellular Mechanisms ◽  
Tissue Integrity ◽  
Tissue Organization

This review addresses the cellular and molecular mechanisms of cadherin-based tissue morphogenesis. Tissue physiology is profoundly influenced by the distinctive organizations of cells in organs and tissues. In metazoa, adhesion receptors of the classical cadherin family play important roles in establishing and maintaining such tissue organization. Indeed, it is apparent that cadherins participate in a range of morphogenetic events that range from support of tissue integrity to dynamic cellular rearrangements. A comprehensive understanding of cadherin-based morphogenesis must then define the molecular and cellular mechanisms that support these distinct cadherin biologies. Here we focus on four key mechanistic elements: the molecular basis for adhesion through cadherin ectodomains, the regulation of cadherin expression at the cell surface, cooperation between cadherins and the actin cytoskeleton, and regulation by cell signaling. We discuss current progress and outline issues for further research in these fields.

scholarly journals The neural G protein Gαo tagged with GFP at an internal loop is functional in C. elegans

2021 ◽  
Author(s):  
Santosh Kumar ◽  
Andrew C Olson ◽  
Michael R Koelle
Keyword(s):  
Genetic Analysis ◽  
G Protein ◽  
Molecular Mechanisms ◽  
Fluorescent Protein ◽  
Protein Complexes ◽  
Egg Laying ◽  
Biochemical Purification ◽  
Internal Loop ◽  
C Elegans

Abstract Gαo is the alpha subunit of the major heterotrimeric G protein in neurons and mediates signaling by every known neurotransmitter, yet the signaling mechanisms activated by Gαo remain to be fully elucidated. Genetic analysis in Caenorhabditis elegans has shown that Gαo signaling inhibits neuronal activity and neurotransmitter release, but studies of the molecular mechanisms underlying these effects have been limited by lack of tools to complement genetic studies with other experimental approaches. Here we demonstrate that inserting the green fluorescent protein (GFP) into an internal loop of the Gαo protein results in a tagged protein that is functional in vivo and that facilitates cell biological and biochemical studies of Gαo. Transgenic expression of Gαo-GFP rescues the defects caused by loss of endogenous Gαo in assays of egg laying and locomotion behaviors. Defects in body morphology caused by loss of Gαo are also rescued by Gαo-GFP. The Gαo-GFP protein is localized to the plasma membrane of neurons, mimicking localization of endogenous Gαo. Using GFP as an epitope tag, Gαo-GFP can be immunoprecipitated from C. elegans lysates to purify Gαo protein complexes. The Gαo-GFP transgene reported in this study enables studies involving in vivo localization and biochemical purification of Gαo to complement the already well-developed genetic analysis of Gαo signaling.

scholarly journals A ubiquitin C-terminal hydrolase is required to maintain osmotic balance and execute actin-dependent processes in the early C. elegansembryo

2002 ◽  
Vol 115 (11) ◽  
pp. 2293-2302
Author(s):  
Susanne Kaitna ◽  
Heinke Schnabel ◽  
Ralf Schnabel ◽  
Anthony A. Hyman ◽  
Michael Glotzer
Keyword(s):  
Caenorhabditis Elegans ◽  
Actin Cytoskeleton ◽  
Cell Polarity ◽  
Maternal Effect ◽  
Embryonic Lethality ◽  
Cleavage Furrow ◽  
Osmotic Regulation ◽  
Osmotic Balance ◽  
Dependent Processes

In the early Caenorhabditis elegans embryo, establishment of cell polarity and cytokinesis are both dependent upon reorganization of the actin cytoskeleton. Mutations in the cyk-3 gene cause maternal effect embryonic lethality. Embryos produced by homozygous cyk-3 mutant animals become multinucleate. We have further analyzed the cyk-3mutant phenotype and have found that cyk-3 mutant embryos fail to properly polarize the actin cytoskeleton and fail to segregate germline determinants. In addition, they fail to assemble an intact cleavage furrow. However, we have found that cyk-3 mutant embryos are intrinsically defective in osmotic regulation and that the cytokinesis defects can be partially rescued by providing osmotic support. The cyk-3 gene has been identified and found to encode a ubiquitin C-terminal hydrolase that is active against model substrates. These data indicate that the deubiquitination of certain substrates by CYK-3 is crucial for cellular osmoregulation. Defects in osmoregulation appear to indirectly affect actin-dependent processes.

scholarly journals Frizzled3 inhibits Vangl2-Prickle3 association to establish planar cell polarity in the vertebrate neural plate

2021 ◽  
Author(s):  
Ilya Chuykin ◽  
Keiji Itoh ◽  
Kyeongmi Kim ◽  
Sergei Y. Sokol
Keyword(s):  
Epithelial Cells ◽  
Complex Formation ◽  
Cell Polarity ◽  
Planar Cell Polarity ◽  
Protein Complexes ◽  
Neural Plate ◽  
Van Gogh

The orientation of epithelial cells in the plane of the tissue, known as planar cell polarity (PCP), is regulated by interactions of asymmetrically localized PCP protein complexes. In the Xenopus neural plate, Van Gogh-like2 (Vangl2) and Prickle3 (Pk3) proteins form a complex at the anterior cell boundaries, but how this complex is regulated in vivo remains largely unknown. Here we use proximity biotinylation and crosslinking approaches to show that Vangl2-Pk3 association is inhibited by Frizzled3 (Fz3), a core PCP protein that is specifically expressed in the neuroectoderm and is essential for the establishment of PCP in this tissue. This inhibition required Fz3-dependent Vangl2 phosphorylaton. Consistent with our observations, the complex of Pk3 with nonphosphorylatable Vangl2 did not polarize in the neural plate. These findings provide evidence for in vivo regulation of Vangl2-Pk3 complex formation and localization by a Frizzled receptor.

Sign in / Sign up

Export Citation Format

Share Document