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

2017 ◽  
Vol 216 (7) ◽  
pp. 1925-1936 ◽  
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.

scholarly journals Emerging Role of Nonmuscle Myosin II and Implications for NMMII Associated Deafness

2011 ◽  
Vol 145 (2_suppl) ◽  
pp. P209-P210
Author(s):  
Elliott Kozin ◽  
Bechara Kachar ◽  
Felipe Salles ◽  
Robert Adelstein ◽  
Xuefei Ma ◽  
...  
Keyword(s):  
Myosin Ii ◽  
Nonmuscle Myosin ◽  
Nonmuscle Myosin Ii

Second-Site Noncomplementation Identifies Genomic Regions Required for Drosophila Nonmuscle Myosin Function During Morphogenesis

Genetics ◽  
1998 ◽  
Vol 148 (4) ◽  
pp. 1845-1863
Author(s):  
Susan R Halsell ◽  
Daniel P Kiehart
Keyword(s):  
Cell Shape ◽  
Myosin Ii ◽  
Nonmuscle Myosin ◽  
Genetic Screens ◽  
Nonmuscle Myosin Ii ◽  
Cell Shape Changes ◽  
Genomic Regions ◽  
Shape Changes ◽  
Strong Interactors

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.

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

2017 ◽  
Vol 28 (8) ◽  
pp. 1034-1042 ◽  
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.

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

Blood ◽  
2014 ◽  
Vol 124 (16) ◽  
pp. 2564-2568 ◽  
Author(s):  
Idinath Badirou ◽  
Jiajia Pan ◽  
Céline Legrand ◽  
Aibing Wang ◽  
Larissa Lordier ◽  
...  
Keyword(s):  
Myosin Ii ◽  
Specific Role ◽  
Nonmuscle Myosin ◽  
Contractile Ring ◽  
Terminal Domain ◽  
Nonmuscle Myosin Ii ◽  
Key Points ◽  
Carboxyl Terminal

Key Points C-terminal domain determines myosin II localization to the MK contractile ring and the specific role of NMII-B in MK polyploidization.

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

Genetics ◽  
2000 ◽  
Vol 155 (3) ◽  
pp. 1253-1265 ◽  
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.

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

2007 ◽  
Vol 46 ◽  
pp. S130 ◽  
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

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

2007 ◽  
Vol 178 (7) ◽  
pp. 1177-1191 ◽  
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.

scholarly journals Methamphetamine learning induces persistent nonmuscle myosin II-dependent spine motility in the basolateral amygdala

2019 ◽  
Author(s):  
Erica J. Young ◽  
Hua Lin ◽  
Theodore M. Kamenecka ◽  
Gavin Rumbaugh ◽  
Courtney A. Miller
Keyword(s):  
Basolateral Amygdala ◽  
Molecular Mechanisms ◽  
Myosin Ii ◽  
Selective Vulnerability ◽  
Actin Dynamics ◽  
Nonmuscle Myosin ◽  
Systemic Injection ◽  
Nonmuscle Myosin Ii ◽  
Window Of Vulnerability ◽  
Induced Changes

ABSTRACTNonmuscle myosin II inhibition (NMIIi) in the basolateral amygdala (BLA) selectively disrupts memories associated with methamphetamine (METH) days after learning, without retrieval. However, the molecular mechanisms underlying this selective vulnerability remain poorly understood. A known function of NMII is to transiently activate dendritic spine actin dynamics with learning. Therefore, we hypothesized that METH-associated learning perpetuates NMII-driven actin dynamics in dendritic spines, leading to an extended window of vulnerability for memory disruption. Two-photon imaging of actin-mediated spine motility in neurons from memory-related structures, BLA and CA1, revealed a persistent increase in spine motility after METH-associated learning that was restricted to BLA neurons. METH-induced changes to BLA spine dynamics were reversed by a single systemic injection of an NMII inhibitor. Thus, a perpetual form of NMII-driven spine actin dynamics in BLA neurons may contribute to the unique susceptibility of METH-associated memories.

scholarly journals Role of Negative Charge on C2 Insert of Nonmuscle Myosin II‐C: Intermittent Structural Oscillation and Aggregation in Neuritogenesis

2015 ◽  
Vol 29 (S1) ◽  
Author(s):  
Shekhar Saha ◽  
Shyamtanu Chattoraj ◽  
Debdatta Halder ◽  
Swagata Goswami ◽  
Kankan Bhattacharyya ◽  
...  
Keyword(s):  
Negative Charge ◽  
Myosin Ii ◽  
Nonmuscle Myosin ◽  
Nonmuscle Myosin Ii

scholarly journals Role of Nonmuscle Myosin II in Migration of Wharton's Jelly-Derived Mesenchymal Stem Cells

2015 ◽  
Vol 24 (17) ◽  
pp. 2065-2077 ◽  
Author(s):  
Sneha Arora ◽  
Shekhar Saha ◽  
Saheli Roy ◽  
Madhurima Das ◽  
Siddhartha S. Jana ◽  
...  
Keyword(s):  
Stem Cells ◽  
Mesenchymal Stem Cells ◽  
Myosin Ii ◽  
Wharton’S Jelly ◽  
Nonmuscle Myosin ◽  
Wharton's Jelly ◽  
Nonmuscle Myosin Ii
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