Carboxyl-terminal-dependent recruitment of nonmuscle myosin II to megakaryocyte contractile ring during polyploidization

Abstract Drosophila is an ideal metazoan model system for analyzing the role of nonmuscle myosin-II (henceforth, myosin) during development. In Drosophila, myosin function is required for cytokinesis and morphogenesis driven by cell migration and/or cell shape changes during oogenesis, embryogenesis, larval development and pupal metamorphosis. The mechanisms that regulate myosin function and the supramolecular structures into which myosin incorporates have not been systematically characterized. The genetic screens described here identify genomic regions that uncover loci that facilitate myosin function. The nonmuscle myosin heavy chain is encoded by a single locus, zipper. Contiguous chromosomal deficiencies that represent approximately 70% of the euchromatic genome were screened for genetic interactions with two recessive lethal alleles of zipper in a second-site noncomplementation assay for the malformed phenotype. Malformation in the adult leg reflects aberrations in cell shape changes driven by myosin-based contraction during leg morphogenesis. Of the 158 deficiencies tested, 47 behaved as second-site noncomplementors of zipper. Two of the deficiencies are strong interactors, 17 are intermediate and 28 are weak. Finer genetic mapping reveals that mutations in cytoplasmic tropomyosin and viking (collagen IV) behave as second-site noncomplementors of zipper during leg morphogenesis and that zipper function requires a previously uncharacterized locus, E3.10/J3.8, for leg morphogenesis and viability.

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Differential role of nonmuscle myosin II isoforms during blebbing of MCF-7 cells

Molecular Biology of the Cell ◽

10.1091/mbc.e16-07-0524 ◽

2017 ◽

Vol 28 (8) ◽

pp. 1034-1042 ◽

Cited By ~ 5

Author(s):

Sumit K. Dey ◽

Raman K. Singh ◽

Shyamtanu Chattoraj ◽

Shekhar Saha ◽

Alakesh Das ◽

...

Keyword(s):

Life Cycle ◽

Actin Filament ◽

Myosin Ii ◽

Nonmuscle Myosin ◽

Nonmuscle Myosin Ii ◽

Different Types ◽

Membrane Protrusions ◽

Bleb Formation ◽

Mcf 7

Bleb formation has been correlated with nonmuscle myosin II (NM-II) activity. Whether three isoforms of NM-II (NM-IIA, -IIB and -IIC) have the same or differential roles in bleb formation is not well understood. Here we report that ectopically expressed, GFP-tagged NM-II isoforms exhibit different types of membrane protrusions, such as multiple blebs, lamellipodia, combinations of both, or absence of any such protrusions in MCF-7 cells. Quantification suggests that 50% of NM-IIA-GFP–, 29% of NM-IIB-GFP–, and 19% of NM-IIC1-GFP–expressing MCF-7 cells show multiple bleb formation, compared with 36% of cells expressing GFP alone. Of interest, NM-IIB has an almost 50% lower rate of dissociation from actin filament than NM-IIA and –IIC1 as determined by FRET analysis both at cell and bleb cortices. We induced bleb formation by disruption of the cortex and found that all three NM-II-GFP isoforms can reappear and form filaments but to different degrees in the growing bleb. NM-IIB-GFP can form filaments in blebs in 41% of NM-IIB-GFP–expressing cells, whereas filaments form in only 12 and 3% of cells expressing NM-IIA-GFP and NM-IIC1-GFP, respectively. These studies suggest that NM-II isoforms have differential roles in the bleb life cycle.

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Faculty Opinions recommendation of Anillin binds nonmuscle myosin II and regulates the contractile ring.

Faculty Opinions – Post-Publication Peer Review of the Biomedical Literature ◽

10.3410/f.1030640.360429 ◽

2006 ◽

Author(s):

Michael Glotzer

Keyword(s):

Myosin Ii ◽

Nonmuscle Myosin ◽

Contractile Ring ◽

Nonmuscle Myosin Ii

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Expansion and concatenation of nonmuscle myosin IIA filaments drive cellular contractile system formation during interphase and mitosis

Molecular Biology of the Cell ◽

10.1091/mbc.e15-10-0725 ◽

2016 ◽

Vol 27 (9) ◽

pp. 1465-1478 ◽

Cited By ~ 70

Author(s):

Aidan M. Fenix ◽

Nilay Taneja ◽

Carmen A. Buttler ◽

John Lewis ◽

Schuyler B. Van Engelenburg ◽

...

Keyword(s):

Actin Filaments ◽

Molecular Motor ◽

Myosin Ii ◽

Cell Movement ◽

Nonmuscle Myosin ◽

Contractile Ring ◽

Contractile System ◽

Nonmuscle Myosin Ii ◽

Dividing Cells ◽

Contractile Forces

Cell movement and cytokinesis are facilitated by contractile forces generated by the molecular motor, nonmuscle myosin II (NMII). NMII molecules form a filament (NMII-F) through interactions of their C-terminal rod domains, positioning groups of N-terminal motor domains on opposite sides. The NMII motors then bind and pull actin filaments toward the NMII-F, thus driving contraction. Inside of crawling cells, NMIIA-Fs form large macromolecular ensembles (i.e., NMIIA-F stacks), but how this occurs is unknown. Here we show NMIIA-F stacks are formed through two non–mutually exclusive mechanisms: expansion and concatenation. During expansion, NMIIA molecules within the NMIIA-F spread out concurrent with addition of new NMIIA molecules. Concatenation occurs when multiple NMIIA-Fs/NMIIA-F stacks move together and align. We found that NMIIA-F stack formation was regulated by both motor activity and the availability of surrounding actin filaments. Furthermore, our data showed expansion and concatenation also formed the contractile ring in dividing cells. Thus interphase and mitotic cells share similar mechanisms for creating large contractile units, and these are likely to underlie how other myosin II–based contractile systems are assembled.

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Genetic Analysis Demonstrates a Direct Link Between Rho Signaling and Nonmuscle Myosin Function During Drosophila Morphogenesis

Genetics ◽

10.1093/genetics/155.3.1253 ◽

2000 ◽

Vol 155 (3) ◽

pp. 1253-1265 ◽

Cited By ~ 8

Author(s):

Susan R Halsell ◽

Benjamin I Chu ◽

Daniel P Kiehart

Keyword(s):

Signal Transduction ◽

Myosin Ii ◽

Signal Transduction Pathway ◽

P Element ◽

Nonmuscle Myosin ◽

Genetic Screens ◽

Induced Mutations ◽

Nonmuscle Myosin Ii ◽

Carboxyl Terminal ◽

Actomyosin Cytoskeleton

Abstract A dynamic actomyosin cytoskeleton drives many morphogenetic events. Conventional nonmuscle myosin-II (myosin) is a key chemomechanical motor that drives contraction of the actin cytoskeleton. We have explored the regulation of myosin activity by performing genetic screens to identify gene products that collaborate with myosin during Drosophila morphogenesis. Specifically, we screened for second-site noncomplementors of a mutation in the zipper gene that encodes the nonmuscle myosin-II heavy chain. We determined that a single missense mutation in the zipperEbr allele gives rise to its sensitivity to second-site noncomplementation. We then identify the Rho signal transduction pathway as necessary for proper myosin function. First we show that a lethal P-element insertion interacts genetically with zipper. Subsequently we show that this second-site noncomplementing mutation disrupts the RhoGEF2 locus. Next, we show that two EMS-induced mutations, previously shown to interact genetically with zipperEbr, disrupt the RhoA locus. Further, we have identified their molecular lesions and determined that disruption of the carboxyl-terminal CaaX box gives rise to their mutant phenotype. Finally, we show that RhoA mutations themselves can be utilized in genetic screens. Biochemical and cell culture analyses suggest that Rho signal transduction regulates the activity of myosin. Our studies provide direct genetic proof of the biological relevance of regulation of myosin by Rho signal transduction in an intact metazoan.

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[331] EXPRESSION, LOCALISATION AND ROLE OF NONMUSCLE MYOSIN II ISOFORMS IN MOUSE HEPATIC STELLATE CELLS

Journal of Hepatology ◽

10.1016/s0168-8278(07)61929-1 ◽

2007 ◽

Vol 46 ◽

pp. S130 ◽

Cited By ~ 1

Author(s):

Z.A. Liu ◽

H. Reynaert ◽

E. Van Rossen ◽

B. Schroyen ◽

L. van Grunsven ◽

...

Keyword(s):

Hepatic Stellate Cells ◽

Myosin Ii ◽

Stellate Cells ◽

Nonmuscle Myosin ◽

Nonmuscle Myosin Ii

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Concerted actions of distinct nonmuscle myosin II isoforms drive intracellular membrane remodeling in live animals

The Journal of Cell Biology ◽

10.1083/jcb.201612126 ◽

2017 ◽

Vol 216 (7) ◽

pp. 1925-1936 ◽

Cited By ~ 29

Author(s):

Oleg Milberg ◽

Akiko Shitara ◽

Seham Ebrahim ◽

Andrius Masedunskas ◽

Muhibullah Tora ◽

...

Keyword(s):

Molecular Mechanisms ◽

Secretory Granules ◽

Myosin Ii ◽

Membrane Remodeling ◽

Nonmuscle Myosin ◽

Nonmuscle Myosin Ii ◽

Mammalian Tissues ◽

Actomyosin Cytoskeleton

Membrane remodeling plays a fundamental role during a variety of biological events. However, the dynamics and the molecular mechanisms regulating this process within cells in mammalian tissues in situ remain largely unknown. In this study, we use intravital subcellular microscopy in live mice to study the role of the actomyosin cytoskeleton in driving the remodeling of membranes of large secretory granules, which are integrated into the plasma membrane during regulated exocytosis. We show that two isoforms of nonmuscle myosin II, NMIIA and NMIIB, control distinct steps of the integration process. Furthermore, we find that F-actin is not essential for the recruitment of NMII to the secretory granules but plays a key role in the assembly and activation of NMII into contractile filaments. Our data support a dual role for the actomyosin cytoskeleton in providing the mechanical forces required to remodel the lipid bilayer and serving as a scaffold to recruit key regulatory molecules.

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Control of nuclear centration in the C. elegans zygote by receptor-independent Gα signaling and myosin II

The Journal of Cell Biology ◽

10.1083/jcb.200703159 ◽

2007 ◽

Vol 178 (7) ◽

pp. 1177-1191 ◽

Cited By ~ 29

Author(s):

Morgan B. Goulding ◽

Julie C. Canman ◽

Eric N. Senning ◽

Andrew H. Marcus ◽

Bruce Bowerman

Keyword(s):

Mitotic Spindle ◽

Myosin Ii ◽

Nonmuscle Myosin ◽

Wild Type ◽

Spindle Positioning ◽

C Elegans ◽

Nonmuscle Myosin Ii ◽

Pulling Forces ◽

Actomyosin Contraction

Mitotic spindle positioning in the Caenorhabditis elegans zygote involves microtubule-dependent pulling forces applied to centrosomes. In this study, we investigate the role of actomyosin in centration, the movement of the nucleus–centrosome complex (NCC) to the cell center. We find that the rate of wild-type centration depends equally on the nonmuscle myosin II NMY-2 and the Gα proteins GOA-1/GPA-16. In centration- defective let-99(−) mutant zygotes, GOA-1/GPA-16 and NMY-2 act abnormally to oppose centration. This suggests that LET-99 determines the direction of a force on the NCC that is promoted by Gα signaling and actomyosin. During wild-type centration, NMY-2–GFP aggregates anterior to the NCC tend to move further anterior, suggesting that actomyosin contraction could pull the NCC. In GOA-1/GPA-16–depleted zygotes, NMY-2 aggregate displacement is reduced and largely randomized, whereas in a let-99(−) mutant, NMY-2 aggregates tend to make large posterior displacements. These results suggest that Gα signaling and LET-99 control centration by regulating polarized actomyosin contraction.

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Anti-β2GPI antibodies stimulate endothelial cell microparticle release via a nonmuscle myosin II motor protein-dependent pathway

Blood ◽

10.1182/blood-2013-03-490318 ◽

2013 ◽

Vol 122 (23) ◽

pp. 3808-3817 ◽

Cited By ~ 23

Author(s):

Venkaiah Betapudi ◽

George Lominadze ◽

Linda Hsi ◽

Belinda Willard ◽

Meifang Wu ◽

...

Keyword(s):

Endothelial Cells ◽

Endothelial Cell ◽

Myosin Ii ◽

Motor Protein ◽

Nonmuscle Myosin ◽

Endothelial Microparticles ◽

Nonmuscle Myosin Ii ◽

Key Points ◽

Dependent Pathway

Key Points Activation of endothelial cells by anti-β2GPI antibodies causes myosin RLC phosphorylation, leading to actin-myosin association. In response to anti-β2GPI antibodies, release of endothelial microparticles, but not E-selectin expression, requires actomyosin assembly.

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