Faculty Opinions recommendation of Dictyostelium and Acanthamoeba myosin II assembly domains go to the cleavage furrow of Dictyostelium myosin II-null cells.

2003 ◽  
Author(s):  
William Bement
Keyword(s):  
Myosin Ii ◽  
Cleavage Furrow ◽  
Dictyostelium Myosin

Role of myosin II tail sequences in its function and localization at the cleavage furrow in Dictyostelium

1999 ◽  
Vol 112 (13) ◽  
pp. 2195-2201 ◽  
Author(s):  
S. Shu ◽  
R.J. Lee ◽  
J.M. LeBlanc-Straceski ◽  
T.Q. Uyeda
Keyword(s):  
Myosin Head ◽  
Myosin Ii ◽  
Equatorial Region ◽  
Chain Gene ◽  
Cleavage Furrow ◽  
Tail Domain ◽  
Specific Domain ◽  
Dictyostelium Myosin ◽  
Skeletal Myosin

Cytoplasmic myosin II accumulates in the cleavage furrow and provides the force for cytokinesis in animal and amoeboid cells. One model proposes that a specific domain in the myosin II tail is responsible for its localization, possibly by interacting with a factor concentrated in the equatorial region. To test this possibility, we have expressed myosins carrying mutations in the tail domain in a strain of Dictyostelium cells from which the endogenous myosin heavy chain gene has been deleted. The mutations used in this study include four internal tail deletions: Mydelta824-941, Mydelta943-1464, Mydelta943-1194 and Mydelta1156-1464. Contrary to the prediction of the hypothesis, immunofluorescence staining demonstrated that all mutant myosins were able to move toward the furrow region. Chimeric myosins, which consisted of a Dictyostelium myosin head and chicken skeletal myosin tail, also efficiently localized to the cleavage furrow. All these deletion and chimeric mutant myosins, except for Mydelta943-1464, the largest deletion mutant, were able to support cytokinesis in suspension. Our data suggest that there is no single specific domain in the tail of Dictyostelium myosin II that is required for its functioning at and localization to the cleavage furrow.

scholarly journals Novel Myosin Heavy Chain Kinase Involved in Disassembly of Myosin II Filaments and Efficient Cleavage in MitoticDictyostelium Cells

2002 ◽  
Vol 13 (12) ◽  
pp. 4333-4342 ◽  
Author(s):  
Akira Nagasaki ◽  
Go Itoh ◽  
Shigehiko Yumura ◽  
Taro Q.P. Uyeda
Keyword(s):  
Myosin Heavy Chain ◽  
Heavy Chain ◽  
Myosin Ii ◽  
Kinase Domain ◽  
Cleavage Furrow ◽  
Wild Type ◽  
Daughter Cells ◽  
Cleavage Process ◽  
Interphase Cells ◽  
Myosin Heavy Chain Kinase

We have cloned a full-length cDNA encoding a novel myosin II heavy chain kinase (mhckC) from Dictyostelium. Like other members of the myosin heavy chain kinase family, themhckC gene product, MHCK C, has a kinase domain in its N-terminal half and six WD repeats in the C-terminal half. GFP-MHCK C fusion protein localized to the cortex of interphase cells, to the cleavage furrow of mitotic cells, and to the posterior of migrating cells. These distributions of GFP-MHCK C always corresponded with that of myosin II filaments and were not observed in myosin II-null cells, where GFP-MHCK C was diffusely distributed in the cytoplasm. Thus, localization of MHCK C seems to be myosin II-dependent. Cells lacking the mhckC gene exhibited excessive aggregation of myosin II filaments in the cleavage furrows and in the posteriors of the daughter cells once cleavage was complete. The cleavage process of these cells took longer than that of wild-type cells. Taken together, these findings suggest MHCK C drives the disassembly of myosin II filaments for efficient cytokinesis and recycling of myosin II that occurs during cytokinesis.

scholarly journals Polar relaxation by dynein-mediated removal of cortical myosin II

2020 ◽  
Vol 219 (8) ◽  
Author(s):  
Bernardo Chapa-y-Lazo ◽  
Motonari Hamanaka ◽  
Alexander Wray ◽  
Mohan K. Balasubramanian ◽  
Masanori Mishima
Keyword(s):  
Recent Work ◽  
Molecular Mechanism ◽  
Molecular Mechanisms ◽  
Myosin Ii ◽  
Cell Cortex ◽  
Cleavage Furrow ◽  
Contractile Ring ◽  
C Elegans ◽  
Polar Cell

Nearly six decades ago, Lewis Wolpert proposed the relaxation of the polar cell cortex by the radial arrays of astral microtubules as a mechanism for cleavage furrow induction. While this mechanism has remained controversial, recent work has provided evidence for polar relaxation by astral microtubules, although its molecular mechanisms remain elusive. Here, using C. elegans embryos, we show that polar relaxation is achieved through dynein-mediated removal of myosin II from the polar cortexes. Mutants that position centrosomes closer to the polar cortex accelerated furrow induction, whereas suppression of dynein activity delayed furrowing. We show that dynein-mediated removal of myosin II from the polar cortexes triggers a bidirectional cortical flow toward the cell equator, which induces the assembly of the actomyosin contractile ring. These results provide a molecular mechanism for the aster-dependent polar relaxation, which works in parallel with equatorial stimulation to promote robust cytokinesis.

scholarly journals Activity of nonmuscle myosin II isoforms determines localization at the cleavage furrow of megakaryocytes

Blood ◽  
2016 ◽  
Vol 128 (26) ◽  
pp. 3137-3145 ◽  
Author(s):  
Anita Roy ◽  
Larissa Lordier ◽  
Stefania Mazzi ◽  
Yunhua Chang ◽  
Valérie Lapierre ◽  
...  
Keyword(s):  
Myosin Ii ◽  
Cleavage Furrow ◽  
Nonmuscle Myosin ◽  
Nonmuscle Myosin Ii

Publisher's Note: There is an Inside Blood Commentary on this article in this issue.

scholarly journals LvsA, a Protein Related to the Mouse Beige Protein, Is Required for Cytokinesis in Dictyostelium

1999 ◽  
Vol 10 (12) ◽  
pp. 4429-4439 ◽  
Author(s):  
Eunice Kwak ◽  
Noel Gerald ◽  
Denis A. Larochelle ◽  
Kalpa K. Vithalani ◽  
Maria L. Niswonger ◽  
...  
Keyword(s):  
Sequence Analysis ◽  
Suspension Culture ◽  
Cell Lines ◽  
Heavy Chain ◽  
Large Volume ◽  
Myosin Ii ◽  
Cleavage Furrow ◽  
Membrane Processing ◽  
Chediak Higashi Syndrome ◽  
Unusual Phenotype

We isolated a Dictyostelium cytokinesis mutant with a defect in a novel locus called large volume sphere A (lvsA). lvsA mutants exhibit an unusual phenotype when attempting to undergo cytokinesis in suspension culture. Early in cytokinesis, they initiate furrow formation with concomitant myosin II localization at the cleavage furrow. However, the furrow is later disrupted by a bulge that forms in the middle of the cell. This bulge is bounded by furrows on both sides, which are often enriched in myosin II. The bulge can increase and decrease in size multiple times as the cell attempts to divide. Interestingly, this phenotype is similar to the cytokinesis failure of Dictyosteliumclathrin heavy-chain mutants. Furthermore, both cell lines cap ConA receptors but form only a C-shaped loose cap. Unlike clathrin mutants,lvsA mutants are not defective in endocytosis or development. The LvsA protein shares several domains in common with the molecules beige and Chediak–Higashi syndrome proteins that are important for lysosomal membrane traffic. Thus, on the basis of the sequence analysis of the LvsA protein and the phenotype of thelvsA mutants, we postulate that LvsA plays an important role in a membrane-processing pathway that is essential for cytokinesis.

scholarly journals Myosin IIB assembly state determines its mechanosensitive dynamics

2019 ◽  
Vol 218 (3) ◽  
pp. 895-908 ◽  
Author(s):  
Eric S. Schiffhauer ◽  
Yixin Ren ◽  
Vicente A. Iglesias ◽  
Priyanka Kothari ◽  
Pablo A. Iglesias ◽  
...  
Keyword(s):  
Mathematical Modeling ◽  
Cell Shape ◽  
Cellular Response ◽  
Myosin Ii ◽  
3T3 Cells ◽  
Dictyostelium Myosin ◽  
Highly Sensitive ◽  
Key Players ◽  
Nih 3T3 ◽  
Shape Changes

Dynamical cell shape changes require a highly sensitive cellular system that can respond to chemical and mechanical inputs. Myosin IIs are key players in the cell’s ability to react to mechanical inputs, demonstrating an ability to accumulate in response to applied stress. Here, we show that inputs that influence the ability of myosin II to assemble into filaments impact the ability of myosin to respond to stress in a predictable manner. Using mathematical modeling for Dictyostelium myosin II, we predict that myosin II mechanoresponsiveness will be biphasic with an optimum established by the percentage of myosin II assembled into bipolar filaments. In HeLa and NIH 3T3 cells, heavy chain phosphorylation of NMIIB by PKCζ, as well as expression of NMIIA, can control the ability of NMIIB to mechanorespond by influencing its assembly state. These data demonstrate that multiple inputs to the myosin II assembly state integrate at the level of myosin II to govern the cellular response to mechanical inputs.

scholarly journals Dynacortin, a Genetic Link between Equatorial Contractility and Global Shape Control Discovered by Library Complementation of a Dictyostelium discoideum Cytokinesis Mutant

2000 ◽  
Vol 150 (4) ◽  
pp. 823-838 ◽  
Author(s):  
Douglas N. Robinson ◽  
James A. Spudich
Keyword(s):  
Dictyostelium Discoideum ◽  
Shape Control ◽  
Myosin Ii ◽  
Genetic Interactions ◽  
Cell Cortex ◽  
Cleavage Furrow ◽  
Family Protein ◽  
Globally Distributed ◽  
Suppression Strategy ◽  
Novel Protein

We have developed a system for performing interaction genetics in Dictyostelium discoideum that uses a cDNA library complementation/multicopy suppression strategy. Chemically mutagenized cells were screened for cytokinesis-deficient mutants and one mutant was subjected to library complementation. Isolates of four different genes were recovered as modifiers of this strain's cytokinesis defect. These include the cleavage furrow protein cortexillin I, a novel protein we named dynacortin, an ezrin-radixin-moesin-family protein, and coronin. The cortexillin I locus and transcript were found to be disrupted in the strain, identifying it as the affected gene. Dynacortin is localized partly to the cell cortex and becomes enriched in protrusive regions, a localization pattern that is similar to coronin and partly dependent on RacE. During cytokinesis, dynacortin is found in the cortex and is somewhat enriched at the poles. Furthermore, it appears to be reduced in the cleavage furrow. The genetic interactions and the cellular distributions of the proteins suggest a hypothesis for cytokinesis in which the contraction of the medial ring is a function of spatially restricted cortexillin I and myosin II and globally distributed dynacortin, coronin, and RacE.

Sign in / Sign up

Export Citation Format

Share Document