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 ◽  
...  

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.

2015 ◽  
Vol 29 (S1) ◽  
Author(s):  
Sumit Dey ◽  
Shekhar Saha ◽  
Siddhartha Jana

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

Genetics ◽  
1998 ◽  
Vol 148 (4) ◽  
pp. 1845-1863
Author(s):  
Susan R Halsell ◽  
Daniel P Kiehart

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.


Blood ◽  
2014 ◽  
Vol 124 (16) ◽  
pp. 2564-2568 ◽  
Author(s):  
Idinath Badirou ◽  
Jiajia Pan ◽  
Céline Legrand ◽  
Aibing Wang ◽  
Larissa Lordier ◽  
...  

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


2007 ◽  
Vol 46 ◽  
pp. S130 ◽  
Author(s):  
Z.A. Liu ◽  
H. Reynaert ◽  
E. Van Rossen ◽  
B. Schroyen ◽  
L. van Grunsven ◽  
...  

2017 ◽  
Vol 216 (7) ◽  
pp. 1925-1936 ◽  
Author(s):  
Oleg Milberg ◽  
Akiko Shitara ◽  
Seham Ebrahim ◽  
Andrius Masedunskas ◽  
Muhibullah Tora ◽  
...  

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.


2007 ◽  
Vol 178 (7) ◽  
pp. 1177-1191 ◽  
Author(s):  
Morgan B. Goulding ◽  
Julie C. Canman ◽  
Eric N. Senning ◽  
Andrew H. Marcus ◽  
Bruce Bowerman

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.


2015 ◽  
Vol 29 (S1) ◽  
Author(s):  
Shekhar Saha ◽  
Shyamtanu Chattoraj ◽  
Debdatta Halder ◽  
Swagata Goswami ◽  
Kankan Bhattacharyya ◽  
...  

2015 ◽  
Vol 24 (17) ◽  
pp. 2065-2077 ◽  
Author(s):  
Sneha Arora ◽  
Shekhar Saha ◽  
Saheli Roy ◽  
Madhurima Das ◽  
Siddhartha S. Jana ◽  
...  

2014 ◽  
Vol 261 ◽  
pp. 666-676 ◽  
Author(s):  
Stefanie Janßen ◽  
Viktoria Gudi ◽  
Chittappen K. Prajeeth ◽  
Vikramjeet Singh ◽  
Katharina Stahl ◽  
...  

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