Native nonmuscle myosin II stability and light chain binding inDrosophila melanogaster

2006 ◽  
Vol 63 (10) ◽  
pp. 604-622 ◽  
Author(s):  
Josef D. Franke ◽  
Amanda L. Boury ◽  
Noel J. Gerald ◽  
Daniel P. Kiehart
Keyword(s):  
Light Chain ◽  
Myosin Ii ◽  
Nonmuscle Myosin ◽  
Nonmuscle Myosin Ii

scholarly journals Myosin Motors and Not Actin Comets Are Mediators of the Actin-based Golgi-to-Endoplasmic Reticulum Protein Transport

2003 ◽  
Vol 14 (2) ◽  
pp. 445-459 ◽  
Author(s):  
Juan M. Durán ◽  
Ferran Valderrama ◽  
Susana Castel ◽  
Juana Magdalena ◽  
Mónica Tomás ◽  
...  
Keyword(s):  
Endoplasmic Reticulum ◽  
Golgi Complex ◽  
Light Chain ◽  
Shiga Toxin ◽  
Actin Filaments ◽  
Protein Transport ◽  
Myosin Ii ◽  
Nonmuscle Myosin ◽  
Nonmuscle Myosin Ii ◽  
Myosin Motors

We have previously reported that actin filaments are involved in protein transport from the Golgi complex to the endoplasmic reticulum. Herein, we examined whether myosin motors or actin comets mediate this transport. To address this issue we have used, on one hand, a combination of specific inhibitors such as 2,3-butanedione monoxime (BDM) and 1-[5-isoquinoline sulfonyl]-2-methyl piperazine (ML7), which inhibit myosin and the phosphorylation of myosin II by the myosin light chain kinase, respectively; and a mutant of the nonmuscle myosin II regulatory light chain, which cannot be phosphorylated (MRLC2AA). On the other hand, actin comet tails were induced by the overexpression of phosphatidylinositol phosphate 5-kinase. Cells treated with BDM/ML7 or those that express the MRLC2AA mutant revealed a significant reduction in the brefeldin A (BFA)-induced fusion of Golgi enzymes with the endoplasmic reticulum (ER). This delay was not caused by an alteration in the formation of the BFA-induced tubules from the Golgi complex. In addition, the Shiga toxin fragment B transport from the Golgi complex to the ER was also altered. This impairment in the retrograde protein transport was not due to depletion of intracellular calcium stores or to the activation of Rho kinase. Neither the reassembly of the Golgi complex after BFA removal nor VSV-G transport from ER to the Golgi was altered in cells treated with BDM/ML7 or expressing MRLC2AA. Finally, transport carriers containing Shiga toxin did not move into the cytosol at the tips of comet tails of polymerizing actin. Collectively, the results indicate that 1) myosin motors move to transport carriers from the Golgi complex to the ER along actin filaments; 2) nonmuscle myosin II mediates in this process; and 3) actin comets are not involved in retrograde transport.

Essential light chain of Drosophila nonmuscle myosin II

1995 ◽  
Vol 16 (5) ◽  
pp. 491-498 ◽  
Author(s):  
Kevin A. Edwards ◽  
Xiao-Jia Chang ◽  
Daniel P. Kiehart
Keyword(s):  
Light Chain ◽  
Myosin Ii ◽  
Nonmuscle Myosin ◽  
Essential Light Chain ◽  
Nonmuscle Myosin Ii

scholarly journals Mammalian Nonmuscle Myosin II Binds to Anionic Phospholipids with Concomitant Dissociation of the Regulatory Light Chain

2016 ◽  
Vol 291 (48) ◽  
pp. 24828-24837 ◽  
Author(s):  
Xiong Liu ◽  
Shi Shu ◽  
Neil Billington ◽  
Chad D. Williamson ◽  
Shuhua Yu ◽  
...  
Keyword(s):  
Light Chain ◽  
Myosin Ii ◽  
Regulatory Light Chain ◽  
Nonmuscle Myosin ◽  
Anionic Phospholipids ◽  
Nonmuscle Myosin Ii

scholarly journals Nonmuscle myosin IIA dynamically guides regulatory light chain phosphorylation and assembly of nonmuscle myosin IIB

2021 ◽  
Author(s):  
Kai Weissenbruch ◽  
Magdalena Fladung ◽  
Justin Grewe ◽  
Laurent Baulesch ◽  
Ulrich Sebastian Schwarz ◽  
...  
Keyword(s):  
Light Chain ◽  
Mammalian Cells ◽  
Myosin Ii ◽  
Regulatory Light Chain ◽  
Force Generation ◽  
Nonmuscle Myosin ◽  
Force Output ◽  
Nonmuscle Myosin Ii ◽  
Phosphorylation Pattern ◽  
Regulatory Light Chain Phosphorylation

Nonmuscle myosin II minifilaments have emerged as central elements for force generation and mechanosensing by mammalian cells. Each minifilament can have a different composition and activity due to the existence of the three nonmuscle myosin II isoforms A, B and C and their respective phosphorylation pattern. We have used CRISPR/Cas9-based knockout cells, quantitative image analysis and mathematical modelling to dissect the dynamic processes that control the formation and activity of heterotypic minifilaments and found a strong asymmetry between isoforms A and B. Loss of NM IIA completely abrogates regulatory light chain phosphorylation and reduces the level of assembled NM IIB. Activated NM IIB preferentially co-assembles into pre-formed NM IIA minifilaments and stabilizes the filament in a force-dependent mechanism. NM IIC is only weakly coupled to these processes. We conclude that NM IIA and B play clearly defined complementary roles during assembly of functional minifilaments. NM IIA is responsible for the formation of nascent pioneer minifilaments. NM IIB incorporates into these and acts as a clutch that limits the force output to prevent excessive NM IIA activity. Together these two isoforms form a balanced system for regulated force generation.

scholarly journals Effect of ATP and regulatory light-chain phosphorylation on the polymerization of mammalian nonmuscle myosin II

2017 ◽  
Vol 114 (32) ◽  
pp. E6516-E6525 ◽  
Author(s):  
Xiong Liu ◽  
Neil Billington ◽  
Shi Shu ◽  
Shu-Hua Yu ◽  
Grzegorz Piszczek ◽  
...  
Keyword(s):  
Light Scattering ◽  
Light Chain ◽  
Myosin Ii ◽  
Monomer Concentration ◽  
Regulatory Light Chain ◽  
Nonmuscle Myosin ◽  
Nonmuscle Myosin Ii ◽  
New Location ◽  
Regulatory Light Chain Phosphorylation

Addition of 1 mM ATP substantially reduces the light scattering of solutions of polymerized unphosphorylated nonmuscle myosin IIs (NM2s), and this is reversed by phosphorylation of the regulatory light chain (RLC). It has been proposed that these changes result from substantial depolymerization of unphosphorylated NM2 filaments to monomers upon addition of ATP, and filament repolymerization upon RLC-phosphorylation. We now show that the differences in myosin monomer concentration of RLC-unphosphorylated and -phosphorylated recombinant mammalian NM2A, NM2B, and NM2C polymerized in the presence of ATP are much too small to explain their substantial differences in light scattering. Rather, we find that the decrease in light scattering upon addition of ATP to polymerized unphosphorylated NM2s correlates with the formation of dimers, tetramers, and hexamers, in addition to monomers, an increase in length, and decrease in width of the bare zones of RLC-unphosphorylated filaments. Both effects of ATP addition are reversed by phosphorylation of the RLC. Our data also suggest that, contrary to previous models, assembly of RLC-phosphorylated NM2s at physiological ionic strength proceeds from folded monomers to folded antiparallel dimers, tetramers, and hexamers that unfold and polymerize into antiparallel filaments. This model could explain the dynamic relocalization of NM2 filaments in vivo by dephosphorylation of RLC-phosphorylated filaments, disassembly of the dephosphorylated filaments to folded monomers, dimers, and small oligomers, followed by diffusion of these species, and reassembly of filaments at the new location following rephosphorylation of the RLC.

scholarly journals Anillin Binds Nonmuscle Myosin II and Regulates the Contractile Ring

2005 ◽  
Vol 16 (1) ◽  
pp. 193-201 ◽  
Author(s):  
Aaron F. Straight ◽  
Christine M. Field ◽  
Timothy J. Mitchison
Keyword(s):  
Light Chain ◽  
Myosin Light Chain ◽  
Cultured Cells ◽  
Contractile Activity ◽  
Myosin Ii ◽  
Human Cells ◽  
Myosin Light Chain Phosphorylation ◽  
Nonmuscle Myosin ◽  
Contractile Ring ◽  
Nonmuscle Myosin Ii

We demonstrate that the contractile ring protein anillin interacts directly with nonmuscle myosin II and that this interaction is regulated by myosin light chain phosphorylation. We show that despite their interaction, anillin and myosin II are independently targeted to the contractile ring. Depletion of anillin in Drosophila or human cultured cells results in cytokinesis failure. Human cells depleted for anillin fail to properly regulate contraction by myosin II late in cytokinesis and fail in abscission. We propose a role for anillin in spatially regulating the contractile activity of myosin II during cytokinesis.

scholarly journals Phosphorylation of Nonmuscle myosin II-A regulatory light chain resists Sendai virus fusion with host cells

2015 ◽  
Vol 5 (1) ◽  
Author(s):  
Provas Das ◽  
Shekhar Saha ◽  
Sunandini Chandra ◽  
Alakesh Das ◽  
Sumit K. Dey ◽  
...  
Keyword(s):  
Light Chain ◽  
Sendai Virus ◽  
Myosin Ii ◽  
Regulatory Light Chain ◽  
Host Cells ◽  
Nonmuscle Myosin ◽  
Virus Fusion ◽  
Nonmuscle Myosin Ii

Ca2+ Sensitivity of Smooth Muscle and Nonmuscle Myosin II: Modulated by G Proteins, Kinases, and Myosin Phosphatase

2003 ◽  
Vol 83 (4) ◽  
pp. 1325-1358 ◽  
Author(s):  
ANDREW P. SOMLYO ◽  
AVRIL V. SOMLYO
Keyword(s):  
Smooth Muscle ◽  
G Proteins ◽  
Cancer Progression ◽  
Light Chain ◽  
Myosin Light Chain ◽  
Myosin Ii ◽  
Nonmuscle Myosin ◽  
Myosin Phosphatase ◽  
Lim Kinase ◽  
Nonmuscle Myosin Ii

Somlyo, Andrew P., and Avril V. Somlyo. Ca2+ Sensitivity of Smooth Muscle and Nonmuscle Myosin II: Modulated by G Proteins, Kinases, and Myosin Phosphatase. Physiol Rev 83: 1325-1358, 2003; 10.1152/physrev.00023.2003.— Ca2+ sensitivity of smooth muscle and nonmuscle myosin II reflects the ratio of activities of myosin light-chain kinase (MLCK) to myosin light-chain phosphatase (MLCP) and is a major, regulated determinant of numerous cellular processes. We conclude that the majority of phenotypes attributed to the monomeric G protein RhoA and mediated by its effector, Rho-kinase (ROK), reflect Ca2+ sensitization: inhibition of myosin II dephosphorylation in the presence of basal (Ca2+ dependent or independent) or increased MLCK activity. We outline the pathway from receptors through trimeric G proteins (Gαq, Gα12, Gα13) to activation, by guanine nucleotide exchange factors (GEFs), from GDP · RhoA · GDI to GTP · RhoA and hence to ROK through a mechanism involving association of GEF, RhoA, and ROK in multimolecular complexes at the lipid cell membrane. Specific domains of GEFs interact with trimeric G proteins, and some GEFs are activated by Tyr kinases whose inhibition can inhibit Rho signaling. Inhibition of MLCP, directly by ROK or by phosphorylation of the phosphatase inhibitor CPI-17, increases phosphorylation of the myosin II regulatory light chain and thus the activity of smooth muscle and nonmuscle actomyosin ATPase and motility. We summarize relevant effects of p21-activated kinase, LIM-kinase, and focal adhesion kinase. Mechanisms of Ca2+ desensitization are outlined with emphasis on the antagonism between cGMP-activated kinase and the RhoA/ROK pathway. We suggest that the RhoA/ROK pathway is constitutively active in a number of organs under physiological conditions; its aberrations play major roles in several disease states, particularly impacting on Ca2+ sensitization of smooth muscle in hypertension and possibly asthma and on cancer neoangiogenesis and cancer progression. It is a potentially important therapeutic target and a subject for translational research.

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