scholarly journals Enlazin, a Natural Fusion of Two Classes of Canonical Cytoskeletal Proteins, Contributes to Cytokinesis Dynamics

2006 ◽  
Vol 17 (12) ◽  
pp. 5275-5286 ◽  
Author(s):  
Edelyn Octtaviani ◽  
Janet C. Effler ◽  
Douglas N. Robinson
Keyword(s):  
Cell Adhesion ◽  
Cell Mechanics ◽  
Cell Shape ◽  
Cytoskeletal Proteins ◽  
Dominant Negative ◽  
Cortical Tension ◽  
Associated Proteins ◽  
Shape Changes ◽  
Novel Protein

Cytokinesis requires a complex network of equatorial and global proteins to regulate cell shape changes. Here, using interaction genetics, we report the first characterization of a novel protein, enlazin. Enlazin is a natural fusion of two canonical classes of actin-associated proteins, the ezrin-radixin-moesin family and fimbrin, and it is localized to actin-rich structures. A fragment of enlazin, enl-tr, was isolated as a genetic suppressor of the cytokinesis defect of cortexillin-I mutants. Expression of enl-tr disrupts expression of endogenous enlazin, indicating that enl-tr functions as a dominant-negative lesion. Enlazin is distributed globally during cytokinesis and is required for cortical tension and cell adhesion. Consistent with a role in cell mechanics, inhibition of enlazin in a cortexillin-I background restores cytokinesis furrowing dynamics and suppresses the growth-in-suspension defect. However, as expected for a role in cell adhesion, inhibiting enlazin in a myosin-II background induces a synthetic cytokinesis phenotype, frequently arresting furrow ingression at the dumbbell shape and/or causing recession of the furrow. Thus, enlazin has roles in cell mechanics and adhesion, and these roles seem to be differentially significant for cytokinesis, depending on the genetic background.

scholarly journals Automated characterization of cell shape changes during amoeboid motility by skeletonization

2010 ◽  
Vol 4 (1) ◽  
pp. 33 ◽  
Author(s):  
Yuan Xiong ◽  
Cathryn Kabacoff ◽  
Jonathan Franca-Koh ◽  
Peter N Devreotes ◽  
Douglas N Robinson ◽  
...  
Keyword(s):  
Cell Shape ◽  
Amoeboid Motility ◽  
Cell Shape Changes ◽  
Shape Changes

scholarly journals Cloning and Characterization of Cell Adhesion Kinase β, a Novel Protein-tyrosine Kinase of the Focal Adhesion Kinase Subfamily

1995 ◽  
Vol 270 (36) ◽  
pp. 21206-21219 ◽  
Author(s):  
Hiroko Sasaki ◽  
Kazuko Nagura ◽  
Masaho Ishino ◽  
Hirotoshi Tobioka ◽  
Kiyoshi Kotani ◽  
...  
Keyword(s):  
Cell Adhesion ◽  
Tyrosine Kinase ◽  
Focal Adhesion Kinase ◽  
Focal Adhesion ◽  
Protein Tyrosine Kinase ◽  
Protein Tyrosine ◽  
Kinase Subfamily ◽  
Novel Protein

scholarly journals Combinatorial patterns of graded RhoA activation and uniform F-actin depletion promote tissue curvature

Development ◽  
2021 ◽  
Author(s):  
Marlis Denk-Lobnig ◽  
Jan F Totz ◽  
Natalie C Heer ◽  
Jörn Dunkel ◽  
Adam C Martin
Keyword(s):  
Cell Mechanics ◽  
Cell Shape ◽  
Transcriptional Activity ◽  
Quantitative Imaging ◽  
Elastic Shell ◽  
Force Transmission ◽  
Rhoa Activation ◽  
Distinct Cell ◽  
Cell Shape Changes ◽  
Shape Changes

During development, gene expression regulates cell mechanics and shape to sculpt tissues. Epithelial folding proceeds through distinct cell shape changes that occur simultaneously in different regions of a tissue. Here, using quantitative imaging in Drosophila melanogaster, we investigate how patterned cell shape changes promote tissue bending during early embryogenesis. We find that the transcription factors Twist and Snail combinatorially regulate a multicellular pattern of lateral F-actin density that differs from the previously described myosin-2 gradient. This F-actin pattern correlates with whether cells apically constrict, stretch, or maintain their shape. We show that the myosin-2 gradient and F-actin depletion do not depend on force transmission, suggesting that transcriptional activity is required to create these patterns. The myosin-2 gradient width results from a gradient in RhoA activation that is refined through the balance between RhoGEF2 and the RhoGAP C-GAP. Our experimental results and simulations of a 3D elastic shell model show that tuning gradient width regulates tissue curvature.

Patterns of Interaction Between Cytoskeletal Elements of Cultured Cells: Modification by Cytochalasin D and A Tumor Promotor

1982 ◽  
Vol 40 ◽  
pp. 8-11
Author(s):  
Manfred Schliwa
Keyword(s):  
Cell Shape ◽  
Intracellular Transport ◽  
Cultured Cells ◽  
Cell Movement ◽  
Structural Basis ◽  
Tumor Promotor ◽  
Associated Proteins ◽  
Cytoskeletal Elements ◽  
Patterns Of Interaction ◽  
Shape Changes

Immunofluorescence and electron microscopy have identified three major filament types in a wide variety of cultured cells: microtubules, intermediate filaments, and microfilaments (F-actin). The complex of these filaments and their associated proteins is now commonly referred to as the cytoskeleton and is generally believed to form the structural basis for such cellular activities as cell movement, intracellular transport, and cell shape changes.

Misdirected vimentin messenger RNA alters cell morphology and motility

2000 ◽  
Vol 113 (13) ◽  
pp. 2433-2443
Author(s):  
E.J. Morris ◽  
K. Evason ◽  
C. Wiand ◽  
T.J. L'Ecuyer ◽  
A.B. Fulton
Keyword(s):  
Messenger Rna ◽  
Cytoskeletal Proteins ◽  
Dominant Negative ◽  
Dominant Negative Effect ◽  
Messenger Rnas ◽  
Vimentin Expression ◽  
Beta Actin ◽  
Associated Proteins ◽  
Negative Effect ◽  
Cellular Phenotypes

Localized messenger RNAs were first observed as embryonic determinants that altered development when mislocalized. In recent years localized mRNAs have been found for several cytoskeletal proteins, including actin, vimentin and several microtubule associated proteins. We sought to determine whether redirecting mRNA for a cytoskeletal protein to an inappropriate address would alter cellular phenotypes. To do so we generated vimentin mRNAs with a myc epitope tag and the (beta)-actin 3′ untranslated region (3′ UTR) as a localization signal. When misdirected vimentin mRNAs are expressed in either fibroblasts or SW13 cells, cells develop numerous, extremely long processes; these cells also move more slowly to enter a wound of the monolayer. In situ hybridization revealed that the misdirected mRNA was often localized in the processes, in contrast to endogenous vimentin mRNA. The processes usually contained actin distal to the transgenic vimentin and microtubules proximal to it. SW13 cells lacking vimentin produced fewer and shorter processes, suggesting a dominant negative effect that involves recruitment of endogenous vimentin. Control experiments that transfected in constructs expressing tagged, correctly localized vimentin, or (beta)-galactosidase that localized through the (beta)-actin 3′ UTR, indicate that neither the shape nor the motility changes are solely due to the level of vimentin expression in the cell. This is direct evidence that the site of expression for at least one cytoskeletal mRNA alters the phenotype of the cell in which it is expressed. Messenger RNA localization is proving to be as essential for the normal maintenance of somatic cell phenotypes as embryonic determinants are for embryogenesis.

scholarly journals The Drosophila Ral GTPase Regulates Developmental Cell Shape Changes through the Jun NH2-terminal Kinase Pathway

1999 ◽  
Vol 146 (2) ◽  
pp. 361-372 ◽  
Author(s):  
Kazunobu Sawamoto ◽  
Per Winge ◽  
Shinya Koyama ◽  
Yuki Hirota ◽  
Chiharu Yamada ◽  
...  
Keyword(s):  
Cell Shape ◽  
Effector Proteins ◽  
Dominant Negative ◽  
Loss Of Function ◽  
Jnk Pathway ◽  
Cell Shape Changes ◽  
Ral Gtpase ◽  
Shape Changes ◽  
Constitutively Active

The Ral GTPase is activated by RalGDS, which is one of the effector proteins for Ras. Previous studies have suggested that Ral might function to regulate the cytoskeleton; however, its in vivo function is unknown. We have identified a Drosophila homologue of Ral that is widely expressed during embryogenesis and imaginal disc development. Two mutant Drosophila Ral (DRal) proteins, DRalG20V and DRalS25N, were generated and analyzed for nucleotide binding and GTPase activity. The biochemical analyses demonstrated that DRalG20V and DRalS25N act as constitutively active and dominant negative mutants, respectively. Overexpression of the wild-type DRal did not cause any visible phenotype, whereas DRalG20V and DRalS25N mutants caused defects in the development of various tissues including the cuticular surface, which is covered by parallel arrays of polarized structures such as hairs and sensory bristles. The dominant negative DRal protein caused defects in the development of hairs and bristles. These phenotypes were genetically suppressed by loss of function mutations of hemipterous and basket, encoding Drosophila Jun NH2-terminal kinase kinase (JNKK) and Jun NH2-terminal kinase (JNK), respectively. Expression of the constitutively active DRal protein caused defects in the process of dorsal closure during embryogenesis and inhibited the phosphorylation of JNK in cultured S2 cells. These results indicate that DRal regulates developmental cell shape changes through the JNK pathway.

Synthesis of putative microtubule-associated proteins by mouse blastocysts during early outgrowth in vitro

1984 ◽  
Vol 62 (9) ◽  
pp. 885-893 ◽  
Author(s):  
William R. Bates ◽  
Gerald M. Kidder
Keyword(s):  
Cell Shape ◽  
Polyacrylamide Gel Electrophoresis ◽  
Blastocyst Stage ◽  
Cytoskeletal Proteins ◽  
Biochemical Basis ◽  
Microtubule Associated Proteins ◽  
Associated Proteins ◽  
Two Stages

The outgrowth of mouse trophoblast in culture provides a simplified model system analogous in certain ways to blastocyst implantation in vivo. Day-four blastocysts cultured for 3 days in vitro undergo extensive changes in cell shape and motility which are likely to involve the complex cytoskeletal system of the trophoblast cells. To explore the biochemical basis of these changes, one set of cytoskeletal proteins, the microtubule-associated proteins (MAPs), was studied. Day 4 blastocysts were labeled with [35S]methionine and blastocyst outgrowths, after 3 days in culture from the blastocyst stage, were labeled with [3H] methionine. Labeled embryos were disrupted and the soluble supernatants were pooled, and newly synthesized proteins from the two stages were coassembled with taxol-stabilized brain microtubule polymer enriched for MAP-binding sites. Double-labeled coassembly proteins (putative MAPS) were then released from the microtubule polymer by treatment with 0.35 M NaCl and analyzed by one-dimensional polyacrylamide gel electrophoresis. 3H/35S dpm ratios were determined for individual protein bands to compare the relative synthesis rates for day 4 blastocyst and day 3 outgrowth MAPs. In spite of the extensive changes in cell shape and motility associated with blastocyst outgrowth, a common set of putative MAPs characterizes the two stages investigated, including several in the size range of tau factors. No synthesis of high molecular weight MAPs comparable with MAP 1 or MAP 2 from brain was detected. The synthesis rates of individual MAPs relative to each other remain constant over this period and are likely coordinated with total protein and tubulin synthesis.

scholarly journals Unified quantitative characterization of epithelial tissue development

eLife ◽  
2015 ◽  
Vol 4 ◽  
Author(s):  
Boris Guirao ◽  
Stéphane U Rigaud ◽  
Floris Bosveld ◽  
Anaïs Bailles ◽  
Jesús López-Gay ◽  
...  
Keyword(s):  
Cell Shape ◽  
Tissue Growth ◽  
Epithelial Tissue ◽  
Tissue Development ◽  
Tissue Morphogenesis ◽  
Quantitative Characterization ◽  
Cell Shape Changes ◽  
The Impact ◽  
Shape Changes

Understanding the mechanisms regulating development requires a quantitative characterization of cell divisions, rearrangements, cell size and shape changes, and apoptoses. We developed a multiscale formalism that relates the characterizations of each cell process to tissue growth and morphogenesis. Having validated the formalism on computer simulations, we quantified separately all morphogenetic events in the Drosophila dorsal thorax and wing pupal epithelia to obtain comprehensive statistical maps linking cell and tissue scale dynamics. While globally cell shape changes, rearrangements and divisions all significantly participate in tissue morphogenesis, locally, their relative participations display major variations in space and time. By blocking division we analyzed the impact of division on rearrangements, cell shape changes and tissue morphogenesis. Finally, by combining the formalism with mechanical stress measurement, we evidenced unexpected interplays between patterns of tissue elongation, cell division and stress. Our formalism provides a novel and rigorous approach to uncover mechanisms governing tissue development.

scholarly journals Combinatorial patterns of graded RhoA activation and uniform F-actin depletion promote tissue curvature

2020 ◽  
Author(s):  
Marlis Denk-Lobnig ◽  
Natalie C Heer ◽  
Adam C Martin
Keyword(s):  
Gene Expression ◽  
Cell Mechanics ◽  
Cell Shape ◽  
Quantitative Imaging ◽  
Expression Patterns ◽  
Rhoa Activation ◽  
Ventral Furrow ◽  
Distinct Cell ◽  
Cell Shape Changes ◽  
Shape Changes

AbstractDuring development, gene expression regulates cell mechanics and shape to sculpt tissues. Epithelial folding proceeds through distinct cell shape changes that occur in different regions of a tissue. Here, using quantitative imaging in Drosophila melanogaster, we investigate how patterned cell shape changes promote tissue bending during early embryogenesis. We find that the transcription factors Twist and Snail combinatorially regulate a unique multicellular pattern of junctional F-actin density, which corresponds to whether cells apically constrict, stretch, or maintain their shape. Part of this pattern is a gradient in junctional F-actin and apical myosin-2, and the width of this gradient regulates tissue curvature. The actomyosin gradient results from a gradient in RhoA activation that is refined by a balance between RhoGEF2 and the RhoGAP C-GAP. Thus, cell behavior in the ventral furrow is choreographed by the interplay of distinct gene expression patterns and this coordination regulates tissue shape.

scholarly journals CDC42 and Rac1 control different actin-dependent processes in the Drosophila wing disc epithelium.

1995 ◽  
Vol 131 (1) ◽  
pp. 151-164 ◽  
Author(s):  
S Eaton ◽  
P Auvinen ◽  
L Luo ◽  
Y N Jan ◽  
K Simons
Keyword(s):  
Epithelial Cells ◽  
Cell Shape ◽  
Larval Instar ◽  
Cell Types ◽  
Wing Disc ◽  
Dominant Negative ◽  
The Third ◽  
Drosophila Wing ◽  
Cell Shape Changes ◽  
Shape Changes

Cdc42 and Rac1 are members of the rho family of small guanosinetriphosphatases and are required for a diverse set of cytoskeleton-membrane interactions in different cell types. Here we show that these two proteins contribute differently to the organization of epithelial cells in the Drosophila wing imaginal disc. Drac1 is required to assemble actin at adherens junctions. Failure of adherens junction actin assembly in Drac1 dominant-negative mutants is associated with increased cell death. Dcdc42, on the other hand, is required for processes that involve polarized cell shape changes during both pupal and larval development. In the third larval instar, Dcdc42 is required for apico-basal epithelial elongation. Whereas normal wing disc epithelial cells increase in height more than twofold during the third instar, cells that express a dominant-negative version of Dcdc42 remain short and are abnormally shaped. Dcdc42 localizes to both apical and basal regions of the cell during these events, and mediates elongation, at least in part, by effecting a reorganization of the basal actin cytoskeleton. These observations suggest that a common cdc42-based mechanism may govern polarized cell shape changes in a wide variety of cell types.

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