Protein motors, such as kinesin and myosin, use chemical energy in the form of ATP to physically move along filaments and perform complex mechanical tasks in the cell, such as intracellular transport, cell division and muscle contraction. Myosin and kinesin are motor proteins that move along actin and microtubules, respectively. The primary goal for this dissertation research is to determine structure-function relationships in Myo I, a class-VII myosin, and in Ncd, a member of the kinesin superfamily. Myosin VII is a member of the myosin family that is found in human tissues and that has high homology to a D. discoideum myosin, Myo I. Work towards obtaining a crystal structure of Myo I are presented in this thesis. A Myo I structure would be the first structure of a class-VII myosin and a MyTH domain and would help discern the role myosin VIIs play in the cell. The structure of a different class of myosin may help better determine force-producing conformational changes in myosins. Ncd is a ...
Protein motors, such as kinesin and myosin, use chemical energy in the form of ATP to physically move along filaments and perform complex mechanical tasks in the cell, such as intracellular transport, cell division and muscle contraction. Myosin and kinesin are motor proteins that move along actin and microtubules, respectively. The primary goal for this dissertation research is to determine structure-function relationships in Myo I, a class-VII myosin, and in Ncd, a member of the kinesin superfamily. Myosin VII is a member of the myosin family that is found in human tissues and that has high homology to a D. discoideum myosin, Myo I. Work towards obtaining a crystal structure of Myo I are presented in this thesis. A Myo I structure would be the first structure of a class-VII myosin and a MyTH domain and would help discern the role myosin VIIs play in the cell. The structure of a different class of myosin may help better determine force-producing conformational changes in myosins. Ncd is a ...
Abstract: Studies in Dictyostelium discoideum have established that the cycle of myosin II bipolar filament assembly and disassembly controls the temporal and spatial localization of myosin II during critical cellular processes, such as cytokinesis and cell locomotion. Myosin heavy chain kinase A (MHCK A) is a key enzyme regulating myosin II filament disassembly through myosin heavy chain phosphorylation in Dictyostelium. Under various cellular conditions, MHCK A is recruited to actin-rich cortical sites and is preferentially enriched at sites of pseudopod formation, and thus MHCK A is proposed to play a role in regulating localized disassembly of myosin II filaments in the cell. MHCK A possesses an aminoterminal coiled-coil domain that participates in the oligomerization, cellular localization, and actin binding activities of the kinase. In the current study, we show that the interaction between the coiled-coil domain of MHCK A and filamentous actin leads to an ~40-fold increase in the initial ...
Abstract: Myosin heavy chain kinase (MHCK) A phosphorylates mapped sites at the C-terminal tail of Dictyostelium myosin II heavy chain, driving disassembly of myosin filaments both in vitro and in vivo. MHCK A is organized into three functional domains that include an N-terminal coiled-coil region, a central kinase catalytic domain unrelated to conventional protein kinases, and a WD repeat domain at the C terminus. MHCK B is a homologue of MHCK A that possesses structurally related catalytic and WD repeat domains. In the current study, we explored the role of the WD repeat domains in defining the activities of both MHCK A and MHCK B using recombinant bacterially expressed truncations of these kinases either with or without their WD repeat domains. We demonstrate that substrate targeting is a conserved function of the WD repeat domains of both MHCK A and MHCK B and that this targeting is specific forDictyostelium myosin II filaments. We also show that the mechanism of targeting involves direct ...
TY - JOUR. T1 - Movement of myosin‐coated structures on actin cables. AU - Sheetz, Michael. AU - Spudich, James A.. PY - 1983/1/1. Y1 - 1983/1/1. N2 - Myosin‐coated spheres from 0.6 to 120 μm in diameter move in vitro on a substratum of polar arrays of actin cables derived from the alga Nitella. The force for this movement is provided by skeletal muscle myosin since it is ATP‐dependent, and N‐ethylmaleimide (NEM) inactivation of the myosin blocks movement. These observations demonstrate that attachment of myosin in a random orientation to structures will enable those structures to move along polar arrays of actin filaments.. AB - Myosin‐coated spheres from 0.6 to 120 μm in diameter move in vitro on a substratum of polar arrays of actin cables derived from the alga Nitella. The force for this movement is provided by skeletal muscle myosin since it is ATP‐dependent, and N‐ethylmaleimide (NEM) inactivation of the myosin blocks movement. These observations demonstrate that attachment ...
A myosin heavy chain polypeptide has been identified and localized in Nicotiana pollen tubes using monoclonal anti-myosin antibodies. The epitopes of these antibodies were found to reside on the myosin heavy chain head and rod portion and were, therefore, designated anti-S-1 (myosin S-1) and anti-LMM (light meromyosin). On Western blots of the total soluble pollen tube proteins, both anti-S-1 and anti-LMM label a polypeptide of approximately 175,000 Mr. Immunofluorescence microscopy shows that both antibodies yield numerous fluorescent spots throughout the whole length of the tube, often with an enrichment in the tube tip. These fluorescent spots are thought to represent vesicles and/or organelles in the pollen tubes. In addition to this common pattern, anti-S-1 stains both the generative cell and the vegetative nuclear envelope. The different staining patterns of the nucleus between anti-S-1 and anti-LMM may be caused by some organization and/or anchorage state of the myosin molecules on the ...
Telokin, an abundant gizzard protein, inhibited phosphorylation of regulatory light chain when filamentous myosin was used as the substrate but no inhibition was observed with myosin subfragment 1. At physiological telokin-to-myosin molar ratio (1:1), the inhibition amounted to a 3.5-fold reduction in the initial phosphorylation rate whereas at high molar excess of telokin over myosin, we observed an up to 20-fold decrease in this rate. In agreement with previous observations [Shirinsky, Vorotnikow, Birukov, Nanaev, Collinge, Lukas, Sellers and Watterson (1993) J. Biol. Chem. 268, 16578Ő16583], telokin did not inhibit phosphorylation of the isolated regulatory light chain of myosin and only moderately (35%) inhibited that of heavy meromyosin. To gain a better understanding of the mechanism of this inhibition, we investigated the effects of telokin on the recently described [Babiychuk, Babiychuk and Sobieszek (1995) Biochemistry 34, 6366Ő6372] oligomeric properties of smooth-muscle myosin ...
Blebbistatin is a small-molecule, high-affinity, noncompetitive inhibitor of myosin II. We have used negative staining electron microscopy to study the effects of blebbistatin on the organization of the myosin heads on muscle thick filaments. Loss of ADP and Pi from the heads causes thick filaments to lose their helical ordering. In the presence of 100 microM blebbistatin, disordering was at least 10 times slower. In the M.ADP state, myosin heads are also disordered. When blebbistatin was added to M.ADP thick filaments, helical ordering was restored. However, blebbistatin did not improve the order of thick filaments lacking bound nucleotide. Addition of calcium to relaxed muscle homogenates induced thick-thin filament interaction and filament sliding. In the presence of blebbistatin, filament interaction was inhibited. These structural observations support the conclusion, based on biochemical studies, that blebbistatin inhibits myosin ATPase and actin interaction by stabilizing the closed switch 2
During muscle development myosin molecules form symmetrical thick filaments which integrate with the thin filaments to produce the regular sarcomeric lattice. In Drosophila indirect flight muscles (IFM) the details of this process can be studied using genetic approaches. The weeP26 transgenic line has a GFP-encoding exon inserted into the single Drosophila muscle myosin heavy chain gene, Mhc. The weeP26 IFM sarcomeres have a unique MHC-GFP-labelling pattern restricted to the sarcomere core, explained by non-translation of the GFP exon following alternative splicing. Characterisation of wild type IFM MHC mRNA confirmed the presence of an alternately spliced isoform, expressed earlier than the major IFM-specific isoform. The two wild-type IFM-specific MHC isoforms differ by the presence of a C-terminal tailpiece in the minor isoform. The sequential expression and assembly of these two MHCs into developing thick filaments suggest a role for the tailpiece in initiating A-band formation. The ...
Viruses are obligatory parasites that depend on host Hula o for their replication as el as for their local and syst movement to establish infection. Although myosin motors are hought to contribute to plant virus infection, their exact role in the specific infection steps have not been addressed. Here we investigated the replication, cell-to-cell and systemic spread of Tobacco mosaic virus (TMV) using dominant negative inhibition of myosin activity. We found that interference with the functions of three class VIII myosins and two class XI myosins significantly reduced the local and long-distance transport o virus. We further determined that the inactivation of myosins XI-2 and XI-K affected the structure and dynamic behavior of th ER leading to aggregation of he viral movement protein (MP) and to a delay in the MP accumulation in plasmodesmata (PD) The inactivation of myosin XI-2 but not of myosin XI-K affected the localization pattern of the 126k replicase subunit and the level of TMV ...
Non-muscle cells express multiple myosin-II electric motor necessary protein myosin IIA, myosin IIB and myosin IIC transcribed from different loci in the individual genome. the dispersing margins had KU14R manufacture been dropped in myosin II? cells. Amazingly, myosin IIcells displayed longer actin filaments connected to focal connections in the scattering margins parallel. Hence, with different assignments in the regulations of the actin network and focal connections development, both myosin IIB and IIA determine the fate of lamellipodia extension during cell spreading. Launch Cell migration has a fundamental function in the maintenance and advancement of the regular physiology of every patient. Deregulation of cell migration is normally suggested as a factor in cancers spread, mental retardation, an infection, and vascular illnesses. Cells initiate migration by increasing their plasma membrane layer in the type of lamellipodia that needs the orchestration of the cell cytoskeleton [1]. KU14R ...
Myosin: Biosynthesis, Classes and Function opens with a discussion on class I myosins, the most varied members of the myosin superfamily and a remarkable group of molecular motor proteins that move actin filaments and produce force. Class I myosin molecules have various physiological roles including maintenance of normal intestinal brush border structure, glucose homeostasis, glomerular filtration, immune function, and tumor promotion and suppression, and new studies are revealing that mutations may lead to diseases including cancer and kidney disease. Thus, the authors review the structure and function of the eight myosin-I isoforms (Myo1a-Myo1h) that are expressed in mammals. Next, the book discusses muscle contractile function and its association with the activity of the protein complex actomyosin, in which myosin exhibits enzyme activity, namely the ability to hydrolyze ATP.. The demonstrated ability of calix[4]arenes C-97, C-99, C-90 and thiacalix[4]arenes C-798 and C-800 can be used for ...
Cardiac-specific myosin light chain kinase (cMLCK) is the kinase predominantly responsible for the maintenance of the basal level of phosphorylation of cardiac myosin light chain 2 (MLC2), which it phosphorylates at Ser-15. This phosphorylation repels the myosin heads from the thick myosin filament and moves them toward the thin actin filament. Unlike smooth muscle cells, MLC2 phosphorylation in striated muscle cells appears to be a positive modulator of Ca2+ sensitivity that shifts the Ca2+-force relationship toward the left and increases the maximal force response and thus does not initiate muscle contraction. Recent studies have revealed an increasing number of details of the biochemical, physiological, and pathophysiological characteristics of cMLCK. The combination of recent technological advances and the discovery of a novel class of biologically active nonstandard peptides will hopefully translate into the development of drugs for the treatment of heart diseases. (Circ J 2013; 77: ...
TY - JOUR. T1 - Effects of the myosin ATPase inhibitor, 2,3-butanedione-2-monoxime, on growth and dimorphic switches of Candida albicans. AU - Woo, M.. AU - Jwa, M.. AU - Kim, J.. AU - Song, K.. PY - 2000/1/1. Y1 - 2000/1/1. N2 - Dimorphic yeast Candida albicans reversibly switches between the form of yeast and hyphae depending on external conditions. We investigated possible roles of the myosin family in the growth and dimorphic switches of C. albicans with a general myosin ATPase inhibitor, 2,3-butanedione-2-monoxime (BDM). Transition to hyphae as well as proliferation by budding was completely inhibited by BDM at 16 mM. Presence of 16 mM BDM did not affect hyphae-to-bud transition but it blocked budding. The effects of BDM on yeast growth and dimorphic switches were reversible. More than 70% of the BDM-treated cells demonstrated defects in the amount and the polarized localization of F-actin as well as in the shape and migration of the nucleus, suggesting that myosin activities are needed in ...
TY - JOUR. T1 - Bio-nanomuscle project. T2 - Contractile properties of single actin filaments in an a-band motility assay system. AU - Suzuki, Madoka. AU - Fujita, Hideaki. AU - Ishiwata, Shinichi. PY - 2004. Y1 - 2004. N2 - We have developed a new microscopic technique to measure the force generated on a single actin filament (FA) in the A-band in which the intact lattice structure composed of myosin thick filaments is maintained; we call this newly developed system Bionanomuscle (or an A-band motility assay system). The A-bands were prepared by selective removal of thin filaments from rabbit skeletal glycerinated myofibrils under optical microscope with the use of gelsolin (a severing and barbed (B)-end capping protein of FA) that was prepared from bovine serum. A polystyrene bead of 1 μm in diameter attached to the B-end of FA (through a gelsolin molecule attached to the surface of the bead) was trapped and manipulated with optical tweezers. The displacement of the bead up to 200 nm ...
Myosin IIIA is a protein that in humans is encoded by the MYO3A gene.[1][2] The protein encoded by this gene belongs to the myosin superfamily. Myosins are actin-dependent motor proteins and are categorized into conventional myosins (class II) and unconventional myosins (classes I and III through XV) based on their variable C-terminal cargo-binding domains. Class III myosins, such as this one, have a kinase domain N-terminal to the conserved N-terminal motor domains and are expressed in photoreceptors. The protein encoded by this gene plays an important role in hearing in humans. Three different recessive, loss of function mutations in the encoded protein have been shown to cause nonsyndromic progressive hearing loss. Expression of this gene is highly restricted, with the strongest expression in retina and cochlea.[2] ...
The evolution of land plants is characterized by whole genome duplications (WGD), which drove species diversification and evolutionary novelties. Detecting these events is especially difficult if they date back to the origin of the plant kingdom. Established methods for reconstructing WGDs include intra- and inter-genome comparisons, KS age distribution analyses, and phylogenetic tree constructions. By analysing 67 completely sequenced plant genomes 775 myosins were identified and manually assembled. Phylogenetic trees of the myosin motor domains revealed orthologous and paralogous relationships and were consistent with recent species trees. Based on the myosin inventories and the phylogenetic trees, we have identified duplications of the entire myosin motor protein family at timings consistent with 23 WGDs, that had been reported before. We also predict 6 WGDs based on further protein family duplications. Notably, the myosin data support the two recently reported WGDs in the common ancestor of all
Fig 1 Positions of subdomains and connectors in the three myosin states and closure of the 50-kDa cleft. a, A comparison of the myosin V motor domain to the Dictyostelium myosin II in the near-rigor and transition states shows the different positions of the subdomains, nucleotide-binding elements and connectors in each state. The structures have been superimposed on the N-terminal subdomains. Relative to this subdomain, the rotation necessary to move from the myosin V state to the near-rigor state is indicated for each subdomain of myosin V; similarly, the rotation necessary to move from the near-rigor to the transition state is indicated on the subdomains of the transition-state structure. Contours of the solvent-accessible cavities for the near-rigor (1,735 ...
SILVA, A C R; KENDRICK-JONES, J; REINACH, Fernando de Castro. Construction of a regulatory myosin light chain capable regulation of myosin. Arquivos de Biologia e Tecnologia[S.l: s.n.], 1988 ...
We have investigated myosin isoform expression during progressive cardiac hypertrophy and the development of congestive heart failure in young male rats. Cardiac enlargement was produced by placing a constricting band (0.024-inch diameter) around the ascending aorta of 25-day-old animals, which resulted in progressively increased stenosis as the rat matured. A 57% and 77% cardiac hypertrophy was observed at 2 and 8 weeks, respectively, with signs of congestive failure at the latter time point. Myosin isoform expression was examined in the subendocardial and subepicardial myocardium of the left ventricle and the free wall of the right ventricle by use of native gel electrophoresis. The percentage of the V3 isoform increased dramatically in both ventricles. In the subendocardial myocardium of the left ventricle, expression of the V3 isoform increased (p less than or equal to 0.05) relative to the subepicardial myocardium at 2, 4, and 8 weeks (17.1% vs. 10.2%, 29.4% vs. 18%, and 46.6% vs. 36.2%). ...
article: Effects of prolonged strenuous endurance exercise on plasma myosin heavy chain fragments and other muscular proteins. Cycling vs running - The Journal of Sports Medicine and Physical Fitness 1998 March;38(1):10-7 - Minerva Medica - Riviste
Looking for online definition of myosin, heavy polypeptide 5 in the Medical Dictionary? myosin, heavy polypeptide 5 explanation free. What is myosin, heavy polypeptide 5? Meaning of myosin, heavy polypeptide 5 medical term. What does myosin, heavy polypeptide 5 mean?
This study illuminates the aspects of cell migration, which is central to many biological processes. To understand cell migration we examine the relationship between local cytoskeletal features and local morphology. We demonstrate this relationship on cells stained for Actin and Myosin We connect the actin/myosin co-localizated structural organization to movements such as membrane protrusions. Membrane protrusions are good indicators of cell migration. Cells can sense the mechanical stiffness or the chemical identity of the surfaces they attach to. We show that these surfaces impact cytoskeletal structure. We develop a classifier to correlate the contextual features extracted from actin/myosin co-localized structure to different cell surfaces. We also describe a new distance based metric to measure the strength of collocated multi-channel two dimensional data for user selected regions. We provide tools, implemented as plugins for the popular ImageJ toolkit, that are available for download by the ...
Both smooth muscle and nonmuscle myosin II activity is regulated by the phosphorylation state of the myosin regulatory light chain (MLC, MRLC, MLC20, Myl9). Phosphorylation of MLC at Thr-18 and Ser-19 activates myosin II motor activity and increases myosin filament stability. This activation has important roles in vari
Activation and Inhibition of Cardiac Thin Filaments by Single and Multiple Domains Constructs of Human Cardiac Myosin Binding Protein-C (cMyBP-C) at Low Calcium Meeting Abstract ...
As shown in this study, Myo1c is one of the main class I myosins expressed in B cells. Previous observations from our group indicated that this molecule could be involved in cytoskeleton rearrangements of B lymphocytes, during the spreading induced by immobilized anti-CD44, B220, or MHC-II Abs (17). During live-cell observations using GFP tagged Myo1c, we observed strong localization of this molecule in all membrane protrusions generated during spreading in addition to enrichment of the protein at the points where membrane extensions begin to appear.. Class I myosins have been identified recently as key players in regulating cell deformation (28). Although overexpression of full-length Myo1c did not significantly alter the cell morphology; when endogenous myosin function is altered by using the dominant negative IQ-Tail construct, the spreading process is modified. The pictures show a nonpolarized spreading pattern, which means that the cells do not produce one or two long projections as control ...
Four Caenorhabditis elegans genes encode muscle-type specific myosin heavy chain isoforms: myo-1 and myo-2 are expressed in the pharyngeal muscles; unc-54 and myo-3 are expressed in body wall muscles. We have used transformation-rescue and lacZ fusion assays to determine sequence requirements for regulated myosin gene expression during development. Multiple tissue-specific activation elements are present for all four genes. For each of the four genes, sequences upstream of the coding region are tissue-specific promoters, as shown by their ability to drive expression of a reporter gene (lacZ) in the appropriate muscle type. Each gene contains at least one additional tissue-specific regulatory element, as defined by the ability to enhance expression of a heterologous promoter in the appropriate muscle type. In rescue experiments with unc-54, two further requirements apparently independent of tissue specificity were found: sequences within the 3 non-coding region are essential for activity while ...
1B7T|br|MYOSIN DIGESTED BY PAPAIN|br|DOI: 10.2210/pdb1b7t/pdb|br|Classification: MYOSIN|br|Deposited: 1999-01-15 Released: 1999-05-12|br|Deposition author(s): Houdusse, A., Kalabokis, V., Himmel, D., Szent-|br|Gyorgyi, A.G., Cohen, C.|br|Organism: Argopecten irradians|br|Structural Biology Knowledgebase: 1B7T (15 models >15 annotations) |br|SBKB.org|br|Experimental Data Snapshot|br|Method: X-RAY DIFFRACTION|br|Resolution: 2.5 Å|br|R-Value Free: 0.297|br|R-Value Work: 0.224|br|wwPDB Validation Full Report|br|Primary Citation |br|Atomic structure of scallop myosin subfragment S1 complexed with MgADP: a novel conformation of the myosin head.|br|Houdusse, A., Kalabokis, V.N., Himmel, D., Szent-Gyorgyi, A.G., Cohen, C.|br|(1999) Cell(Cambridge,Mass.) 97: 459-470|br|http://www.rcsb.org/pdb/explore/explore.do?structureId=1B7T
Tryptic and chymotryptic light meromyosin paracrystals from red and cardiac muscles of rabbit show a negative and positive staining pattern with uranyl acetate and phosphotungstate that sharply differs from that of white muscle light meromyosin paracrystals. The main periodicity of about 430 A is the same regardless of the source of light meromyosin. The results are discussed in terms of the molecular structure and the functional properties of various myosins.. ...
Myosin regulatory light polypeptide 9 is a protein that in humans is encoded by the MYL9 gene. Myosin, a structural component of muscle, consists of two heavy chains and four light chains. The protein encoded by this gene is a myosin light chain that may regulate muscle contraction by modulating the ATPase activity of myosin heads. The encoded protein binds calcium and is activated by myosin light chain kinase. Two transcript variants encoding different isoforms have been found for this gene. GRCh38: Ensembl release 89: ENSG00000101335 - Ensembl, May 2017 GRCm38: Ensembl release 89: ENSMUSG00000067818 - Ensembl, May 2017 Human PubMed Reference:. Mouse PubMed Reference:. Kumar CC, Mohan SR, Zavodny PJ, Narula SK, Leibowitz PJ (May 1989). Characterization and differential expression of human vascular smooth muscle myosin light chain 2 isoform in nonmuscle cells. Biochemistry. 28 (9): 4027-35. doi:10.1021/bi00435a059. PMID 2526655. Entrez Gene: myosin. Stelzl U, Worm U, Lalowski M, et al. ...
Acanthamoeba myosin-II forms filaments of two different sizes. Thin bipolar filaments 7 nm wide and 200 nm long consist of 16 myosin-II molecules. Thick bipolar filaments of variable width (14-19 nm) consist of 40 or more myosin-II molecules. Both have a central bare zone 90 nm long and myosin heads projecting laterally at the ends. The heads are arranged in rows spaced 15 nm apart. In the case of the thin myosin-II filaments there are two molecules per row. The thick filaments are formed rapidly and reversibly in the presence of 6-10 mM MgCl2 (or any of five other different divalent cations tested) by the lateral aggregation of thin myosin-II filaments. Acid pH also favors thick filament formation. Neither the myosin-II concentration (50-1,000 micrograms/ml) nor ATP has an effect on the morphology of the filaments. The polymerization mechanism was studied quantitatively by measuring the amount of polymer formed (Cp) under various conditions as a function of total myosin-II concentration (Ct). ...
This decrease in motor velocity as a function of Myo2p concentration suggests that Myo2p is a nonprocessive motor. To quantify the processivity of Myo2p, we determined its duty ratio. Processive motors, such as conventional kinesin, have duty ratios of close to 1.0 (Howard et al. 1989), whereas nonprocessive motors have very low duty ratios; for example skeletal muscle myosin II has a duty ratio of 0.04 (Uyeda et al. 1990; Harris and Warshaw 1993). To determine the Myo2p duty ratio, the average filament velocities were plotted over a range of motor density and fit to Formula 1. The results indicate that the maximum duty ratio for Myo2p is ∼0.2, a value significantly lower than that expected for a processive motor, but still significantly higher than values observed for the highly nonprocessive motor, myosin-II (duty ratio = 0.04; Fig. 4 A).. The landing rate data for Myo2p was fit to Formula 2, a model originally developed by Hancock and Howard 1998 to examine the landing rate of kinesin (see ...
TY - JOUR. T1 - Involvement of headless myosin X in the motility of immortalized gonadotropin-releasing hormone neuronal cells. AU - Wang, Jun Jie. AU - Fu, Xiu Qing. AU - Guo, Yu Guang. AU - Yuan, Lin. AU - Gao, Qian Qian. AU - Yu, Hua Li. AU - Shi, Heng Liang. AU - Wang, Xing Zhi. AU - Xiong, Wen Cheng. AU - Zhu, Xiao Juan. N1 - Funding Information: This work was supported by the National Natural Science Foundation of China (30670689) and the Program for New Century Excellent Talents in University (NCET-07-0173), Specialized Research Fund for the Doctoral Program of High Education (20060200008) and Scientific Research Foundation for the Returned Overseas Chinese Scholars from the Ministry of Education of China.. PY - 2009/5. Y1 - 2009/5. N2 - Myosin X (Myo X), an unconventional myosin with a tail homology 4-band 4.1/ezrin/radixin/moesin (MyTH4-FERM) tail, is expressed ubiquitously in various mammalian tissues. In addition to the full-length Myo X (Myo X FL), a headless form is synthesized in ...
The actomyosin network is thought to support fundamental processes of plant development and cell expansion such as polarized elongation of root hairs and the diffuse growth of epidermal and mesophyll cells. Inhibition of myosins via pharmacological treatments represents one of the key approaches for understanding of their roles in different cellular processes. However, the use of the standard plant myosin inhibitor, 2,3-butanedionemonoxime (BDM), is questioned as it requires a high concentration and may not be as specific as desired. By testing drugs that inhibit animal and yeast myosins V, the Staiger laboratory previously found pentabromopseudilin (PBP) as a potential inhibitor of plant myosins in vivo. In order to verify PBP as a plant myosin inhibitor in vitro, an actin filament gliding assay powered by chicken Myosin Va (MyoVa) was developed as a positive control using Total Internal Reflection Fluorescence Microscopy (TIRFM). Here, we partially purified a YFP-tagged Myosin XIK from Arabidopsis
TY - JOUR. T1 - The role of myosin II in glioma invasion of the brain. AU - Beadle, Christopher. AU - Assanah, Marcela C.. AU - Monzo, Pascale. AU - Vallee, Richard. AU - Rosenfeld, Steven S.. AU - Canoll, Peter. PY - 2008/8. Y1 - 2008/8. N2 - The ability of gliomas to invade the brain limits the efficacy of standard therapies. In this study, we have examined glioma migration in living brain tissue by using two novel in vivo model systems. Within the brain, glioma cells migrate like nontransformed, neural progenitor cells - extending a prominent leading cytoplasmic process followed by a burst of forward movement by the cell body that requires myosin II. In contrast, on a two-dimensional surface, glioma cells migrate more like fibroblasts, and they do not require myosin II to move. To explain this phenomenon, we studied glioma migration through a series of synthetic membranes with defined pore sizes. Our results demonstrate that the A and B isoforms of myosin II are specifically required when a ...
TY - JOUR. T1 - Dynamic regulation of vascular myosin light chain (MYL9) with injury and aging. AU - Shehadeh, Lina A.. AU - Webster, Keith A.. AU - Hare, Joshua M.. AU - Vazquez-Padron, Roberto I.. N1 - Copyright: Copyright 2012 Elsevier B.V., All rights reserved.. PY - 2011/10/7. Y1 - 2011/10/7. N2 - Background: Aging-associated changes in the cardiovascular system increase the risk for disease development and lead to profound alterations in vascular reactivity and stiffness. Elucidating the molecular response of arteries to injury and age will help understand the exaggerated remodeling of aging vessels. Methodology/Principal Findings: We studied the gene expression profile in a model of mechanical vascular injury in the iliac artery of aging (22 months old) and young rats (4 months old). We investigated aging-related variations in gene expression at 30 min, 3 d and 7 d post injury. We found that the Myosin Light Chain gene (MYL9) was the only gene differentially expressed in the aged versus ...
The development of cell-cell junctions was a fundamental step in metazoan evolution and human health depends on the formation and function of cell junctions. the apical junction and an apically-directed actin flow generated by NMII contraction.45 As a major force generator and component of adherens junctions NMII may also have yet to be discovered roles at the junction. Myo1e at Specialized Glomerular Junctional Complexes Class I myosins are single-headed motors with short tails that bind to lipid membranes.46 They are phylogenetically ancient and are found in amoebae fungi and animals. Many organisms express several class I myosins; the slime mold expresses seven46 and humans express eight class I myosins.3 Myo1a one of the best known class I myosins forms a link between the plasma membrane and the actin filaments of intestinal microvilli.47 Myo1e (initially called human myosin-1c or myr3) has a longer tail that contains both a membrane-binding domain and an SH3 domain48 (Fig.?1). Myo1e is ...
Phosphorylation of the regulatory light chain of myosin II (MLC(20)) at the activation sites promotes both the motor activity and the filament formation of myosin II, thus playing an important role in various cell motile processes. In contrast, the physiological function of phosphorylation of MLC(20) at the inhibitory sites is unknown. Here we report for the first time the function of the inhibitory site phosphorylation in the cells. We successfully produced the antibodies specifically recognizing the phosphorylation sites of MLC(20) at Ser1, and the platelet-derived growth factor (PDGF)-induced change in the phosphorylation at the Ser1 was monitored. The phosphorylation of MLC(20) at the Ser1 significantly increased during the PDGF-induced actin cytoskeletal reorganization. PDGF disassembled the stress fibers, and this was attenuated with the expression of unphosphorylatable MLC(20) at the Ser1/Ser2 phosphorylation sites. The present results suggest that the down-regulation of myosin II activity
TY - JOUR. T1 - Myosin II contributes to cell-scale actin network treadmilling through network disassembly. AU - Wilson, Cyrus A.. AU - Tsuchida, Mark A.. AU - Allen, Greg M.. AU - Barnhart, Erin L.. AU - Applegate, Kathryn T.. AU - Yam, Patricia T.. AU - Ji, Lin. AU - Keren, Kinneret. AU - Danuser, Gaudenz. AU - Theriot, Julie A.. PY - 2010/5/20. Y1 - 2010/5/20. N2 - Crawling locomotion of eukaryotic cells is achieved by a process dependent on the actin cytoskeleton: protrusion of the leading edge requires assembly of a network of actin filaments, which must be disassembled at the cell rear for sustained motility. Although ADF/cofilin proteins have been shown to contribute to actin disassembly, it is not clear how activity of these locally acting proteins could be coordinated over the distance scale of the whole cell. Here we show that non-muscle myosin II has a direct role in actin network disassembly in crawling cells. In fish keratocytes undergoing motility, myosin II is concentrated in ...
To characterize the structure of jaw muscle fibres expressing masticatory (superfast) myosin, X-ray diffraction patterns of glycerinated fibres of dog masseter were compared with those of dog tibialis anterior in the relaxed state. Meridional reflections of masseter fibres were laterally broad, indicating that myosin filaments are staggered along the filament axis. Compared with tibialis anterior fibres, the peak of the first myosin layer line of masseter fibres was lower in intensity and shifted towards the meridian, while lattice spacings were larger at a similar sarcomere length. These suggest that the myosin heads of masticatory fibres are mobile, and tend to protrude from the filament shaft towards actin filaments. Lowering temperature or treating with N-phenylmaleimide shifted the peak of the first myosin layer line of tibialis anterior fibres towards the meridian and the resulting profile resembled that of masseter fibres. This suggests that the protruding mobile heads in the non-treated ...
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TY - JOUR. T1 - Reconciling the working strokes of a single head of skeletal muscle myosin estimated from laser-trap experiments and crystal structures. AU - Sleep, John. AU - Lewalle, Alexandre. AU - Smith, David Aitchison. PY - 2006. Y1 - 2006. M3 - Article. VL - 103. SP - 1278. EP - 1282. JO - Proceedings of the National Academy of Sciences of the United States of America. JF - Proceedings of the National Academy of Sciences of the United States of America. SN - 0027-8424. IS - 5. ER - ...
Cell division concludes with cytokinesis, a process driven by a contractile ring of actin and myosin that lies underneath the plasma membrane at the cells equator. Although myosin is essential for cytokinesis in various animal models, whether and to what extent this reflects its motor activity or its ability to crosslink actin has been a matter of debate. Now Daniel Osorio, Ana Carvalho and colleagues tackle this problem with the help of CRISPR/Cas9 gene editing and C. elegans embryos. Mutations introduced into the ATPase domain of non-muscle myosin-2 (NMY-2, the sole myosin required for early cytokinesis) bind to actin but fail to translocate it in vitro. In the animal, these motor-dead mutations lead to adult sterility and embryonic inviability, and fail to support cytokinesis. When motor activity is partially impaired, cytokinesis is prolonged and more sensitive to reductions in overall NMY-2 levels. Finally, although actin levels in the contractile ring are not affected by either NMY-2 ...
In addition, mutations in zipper (Drosophila myosin II) have been shown to lead to disruptions in the formation of boundaries in the imaginal disc and ommatidia (Major and Irvine, 2006; Fiehler and Wolff, 2007), and mutations in Myh10 in mice lead to hydrocephalus as a result of disruptions in the ventricular layer boundary (Ma et al., 2007). MYH10 and MYH14 are distributed at boundaries between different cell types within the OC, and the alignments of these cell types was affected in blebbistatin-treated explants and, to a lesser extent, in Myh10DN mutants. The specific role of myosin II in boundary formation is unclear. However, its ability to regulate contractile tension along F-actin cables through crosslinking has been implicated (Major and Irvine, 2006; Ma et al., 2007).. Myosin II has also been shown to regulate CE during germband extension in Drosophila through modulation of junctional remodeling (Bertet et al., 2004; Zallen and Wieschaus, 2004). In particular, cell-cell junctions ...
a. A b. B c. C d. D e. E 46. The contraction of skeletal muscles is based on: a. Myosin filaments shortening b. Actin filaments shortening c. Actin and myosin filaments both shortening d. Actin and myosin filaments sliding past each other e. Cycles of binding and release orchestrated by the heads of actin filaments 47. A skeletal muscle deprived of adequate ATP will: a. Immediately relax b. Enter a state where actin and myosin are unable to separate c. Fire many more action potentials than usual d. Sequester all free calcium ions into the sarcoplasmic reticulum 48. Listed below are some of the steps involved in skeletal muscle contraction. These steps are not listed in chronological order. Which step occurs last? a. Neurotransmitters are released into the neuromuscular junction b. Myosin-binding sites are exposed on thin filaments c. The action potential travels deep into the muscle fiber cell via T tubules d. A depolarization of the muscle fiber occurs e. Ca2+ is released from the sarcoplasmic ...
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Functional characteristics of Myosin V and Broad Complex during Drosophila oogenesis identification and analysis of myosin genes in Drosophila ...
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TY - JOUR. T1 - The molecular effects of skeletal muscle myosin regulatory light chain phosphorylation. AU - Greenberg, Michael J.. AU - Mealy, Tanya R.. AU - Watt, James D.. AU - Jones, Michelle. AU - Szczesna-Cordary, Danuta. AU - Moore, Jeffrey R.. PY - 2009/8. Y1 - 2009/8. N2 - Phosphorylation of the myosin regulatory light chain (RLC) in skeletal muscle has been proposed to act as a molecular memory of recent activation by increasing the rate of force development, ATPase activity, and isometric force at submaximal activation in fibers. It has been proposed that these effects stem from phosphorylation-induced movement of myosin heads away from the thick filament backbone. In this study, we examined the molecular effects of skeletal muscle myosin RLC phosphorylation using in vitro motility assays. We showed that, independently of the thick filament backbone, the velocity of skeletal muscle myosin is decreased upon phosphorylation due to an increase in the myosin duty cycle. Furthermore, we ...
TY - JOUR. T1 - The interaction of F-actin with phosphorylated and unphosphorylated myosins IA and IB from Acanthamoeba castellanii.. AU - Albanesi, J. P.. AU - Hammer, J. A.. AU - Korn, E. D.. PY - 1983/8/25. Y1 - 1983/8/25. N2 - Myosins IA and IB from Acanthamoeba castellanii are single-headed molecules which, upon phosphorylation of their heavy chains by a specific kinase, express actin-activated Mg2+-ATPase activity. These myosins show no tendency to self-associate under assay conditions, a property which allows unambiguous kinetic and actin-binding data to be obtained. Both myosin isoenzymes exhibit a complex dependence of actomyosin ATPase activity on F-actin concentration. A conventional hyperbolic dependence is observed at low concentrations of F-actin but at higher F-actin concentrations, inhibition and then apparent reactivation are seen to occur. From those early portions of the velocity profiles which do not deviate from simple Michaelis-Menten type kinetics, values for the Vmax (10 ...
TY - JOUR. T1 - Correlation between myosin heavy chain expression and actomyosin atpase activity in human muscle fibers. AU - Proctor, David Nathan. AU - Joyner, M. J.. AU - Sieck, G. C.. PY - 1996. Y1 - 1996. N2 - The myosin heavy chain (MHC) is the site of ATP hydrolysis during crossbridge cycling; therefore, a correlation should exist between MHC isoform expression and actomyosin ATPase activity in human muscle fibers. Needle biopsies were obtained from the quadriceps femoris of 5 sedentary subjects (21-43 yr). Fibers were classified histochemicalîy and also on the basis of MHC isoform immunoreactivity. Calcium-activated actomyosin ATPase activity of muscle fibers (20 fibers per type) was determined in alternate serial sections using a quantitative histochemical procedure (Blanco & Sieck, Histochem J. 24: 431-444, 1992}. The mean actomyosin ATPase activity (mmol Pi/ liter tissue/min) of type I fibers (52.8±6.1) was two-fold lower (p,0.05) than that of type Ha (102.1 + 13.3) and type IIx ...
TY - JOUR. T1 - Smooth muscle myosin expression, isoform composition, and functional activities in rat corpus cavernosum altered by the streptozotocin-induced type 1 diabetes. AU - Zhang, Xinhua. AU - Kanika, Nirmala D.. AU - Melman, Arnold. AU - DiSanto, Michael E.. PY - 2012/1. Y1 - 2012/1. N2 - Diabetes mellitus (DM) is a quite common chronic disease, and the prevalence of erectile dysfunction (ED) is three times higher in this large population. Although diabetes-related ED has been studied extensively, the actin-myosin contractile apparatus was not examined. The mRNAs encoding smooth muscle myosin (SMM) heavy chains (MHC) and essential light chains (LC 17) exist as several different alternatively spliced isoforms with distinct contractile properties. Recently, we provided novel data that blebbistatin (BLEB), a specific myosin II inhibitor, potently relaxed corpus cavernosum smooth muscle (CCSM). In this study, we examine whether diabetes alters SMM expression, alternative splicing, and/or ...
Myosins are molecular motors that convert chemical energy into mechanical force. Vertebrate cells contain three myosin II isoforms, designated as myosin IIA, IIB and IIC, and each isoform has unique biochemical and biophysical charasterics. It is generally accepted that all three isoforms are involved in regulating actin structures and cell contraction. However, it is unknown what role(s) each isoform plays in maintaining actin structures and generating cellular force. Experiments presented in this thesis will begin to document what role myosin IIA plays in endothelial cell contraction and actin dynamics.;Myosin IIA ablated from endothelial cells by infection with adenovirus encoding a short hairpin interfering RNA targeting mouse nonmuscle myosin IIA (shRNAi-IIA) mediated knockdown of myosin IIA, altered endothelial cell shape and induced reorganization of actin filaments. Myosin IIB content was unaltered and myosin IIB remained associated with actin filaments. Cell attachement and spreading occured
TY - JOUR. T1 - Regulation of myosin light chain kinase and telokin expression in smooth muscle tissues. AU - Herring, B. Paul. AU - El-Mounayri, Omar. AU - Gallagher, Patricia J.. AU - Yin, Feng. AU - Zhou, Jiliang. PY - 2006/11/24. Y1 - 2006/11/24. N2 - The mylk1 gene is a large gene spanning ∼250 kb and comprising at least 31 exons. The mylk1 gene encodes at least four protein products: two isoforms of the 220-kDa myosin light chain kinase (MLCK), a 130-kDa MLCK, and telokin. Transcripts encoding these products are derived from four independent promoters within the mylk1 gene. The kinases expressed from the mylk1 gene have been extensively characterized and function to regulate the activity of nonmuscle and smooth muscle myosin II. Activation of these myosin motors by MLCK modulates a variety of contractile processes, including smooth muscle contraction, cell adhesion, migration, and proliferation. Dysregulation of these processes contributes to a number of diseases. The noncatalytic gene ...
The interaction between the calcium-binding protein S100A4 and the C-terminal fragments of nonmuscle myosin heavy chain IIA has been studied by equilibrium and kinetic methods. Using site-directed mutants, we conclude that Ca(2+) binds to the EF2 domain of S100A4 with micromolar affinity and that the K(d) value for Ca(2+) is reduced by several orders of magnitude in the presence of myosin target fragments. The reduction in K(d) results from a reduced dissociation rate constant (from 16 s(-1) to 0.3 s(-1) in the presence of coiled-coil fragments) and an increased association rate constant. Using peptide competition assays and NMR spectroscopy, we conclude that the minimal binding site on myosin heavy chain IIA corresponds to A1907-G1938; therefore, the site extends beyond the end of the coiled-coil region of myosin. Electron microscopy and turbidity assays were used to assess myosin fragment filament disassembly by S100A4. The latter assay demonstrated that S100A4 binds to the filaments and ...
Three novel beta cardiac myosin heavy chain (MHC) gene missense mutations, Phe513Cys, Gly716Arg, and Arg719Trp, which cause familial hypertrophic cardiomyopathy (FHC) are described. One mutation in exon 15 (Phe513Cys) does not alter the charge of the encoded amino acid, and affected family members have a near normal life expectancy. The Gly716Arg mutation (exon 19; charge change of +1) causes FHC in three family members, one of whom underwent transplantation for heart failure. The Arg719Trp mutation (exon 19; charge change of -1) was found in four unrelated FHC families with a high incidence of premature death and an average life expectancy in affected individuals of 38 yr. A comparable high frequency of disease-related deaths in four families with the Arg719Trp mutation suggests that this specific gene defect directly accounts for the observed malignant phenotype. Further, the significantly different life expectancies associated with the Arg719Trp vs. Phe513Cys mutation (P | 0.001) support the
TY - JOUR. T1 - C0 and C1 N-terminal Ig domains of myosin binding protein C exert different effects on thin filament activation. AU - Harris, Samantha P.. AU - Belknap, Betty. AU - Van Sciver, Robert E.. AU - White, Howard D.. AU - Galkin, Vitold E.. PY - 2016/2/9. Y1 - 2016/2/9. N2 - Mutations in genes encoding myosin, the molecular motor that powers cardiac muscle contraction, and its accessory protein, cardiac myosin binding protein C (cMyBP-C), are the two most common causes of hypertrophic cardiomyopathy (HCM). Recent studies established that the N-terminal domains (NTDs) of cMyBP-C (e.g., C0, C1, M, and C2) can bind to and activate or inhibit the thin filament (TF). However, the molecular mechanism(s) by which NTDs modulate interaction of myosin with the TF remains unknown and the contribution of each individual NTD to TF activation/inhibition is unclear. Here we used an integrated structure-function approach using cryoelectron microscopy, biochemical kinetics, and force measurements to ...
Oxidative stress-induced neuronal apoptosis plays an important role in the progression of central nervous system (CNS) diseases. In our study, when neuronal cells were exposed to hydrogen peroxide (H2O2), an exogenous oxidant, cell apoptosis was observed with typical morphological changes including membrane blebbing, neurite retraction and cell contraction. The actomyosin system is considered to be responsible for the morphological changes, but how exactly it regulates oxidative stress-induced neuronal apoptosis and the distinctive functions of different myosin II isoforms remain unclear. We demonstrate that myosin IIA was required for neuronal contraction, while myosin IIB was required for neuronal outgrowth in normal conditions. During H2O2-induced neuronal apoptosis, myosin IIA, rather than IIB, interacted with actin filaments to generate contractile forces that leaded to morphological changes. Moreover, myosin IIA knockout using CRISPR/Cas9 reduced H2O2-induced neuronal apoptosis and the associated
Postnatal myosin heavy chain isoform expression in normal mice and mice null for IIb or IId myosin heavy chains Journal Article ...
TY - JOUR. T1 - Identification of Tau and MAP2 as novel substrates of Rho-kinase and myosin phosphatase. AU - Amano, Mutsuki. AU - Kaneko, Takako. AU - Maeda, Akio. AU - Nakayama, Masanori. AU - Ito, Masaaki. AU - Yamauchi, Takashi. AU - Goto, Hideyuki. AU - Fukata, Yuko. AU - Oshiro, Noriko. AU - Shinohara, Azusa. AU - Iwamatsu, Akihiro. AU - Kaibuchi, Kozo. N1 - Copyright: Copyright 2008 Elsevier B.V., All rights reserved.. PY - 2003/11. Y1 - 2003/11. N2 - Rho-kinase and myosin phosphatase are implicated in the phosphorylation-state of myosin light chain downstream of Rho, which is thought to induce smooth muscle contraction and stress fibre formation in non-muscle cells. Here, we found that microtubule-associated proteins, Tau and MAP2, interacted with the myosin-binding subunit (MBS) of myosin phosphatase, and were the possible substrates of both Rho-kinase and myosin phosphatase. We determined the phosphorylation sites of Tau (Thr245, Thr377, Ser409) and MAP2 (Ser1796) by Rho-kinase. We ...
Slovenščina (Slovenian). In the present research we tried to prove, that specific myosin heavy chain is relat-ed to a prevalent metabolic type and that activ-ities of succinate-dehydrogenase and a glycerophosphate dehydrogenase in the same fibre types can be different in different muscles. We defined the muscle fibre types (I, IIA and IIB) on transversal sections of frozen muscles accord-ing to their myofibrillar ATPase activity in alka-line and acidic media. We excised extensor digitorum longus, tibialis anterior and diaphragm muscles of five Wistar rats. In the same fibres we immunohistochemically demonstrated myosin heavy chains (MHC) I, IIA, IIB and IIX and histochemically and histophotometrically deter-mined the activities of succinate-dehydrogenase and glycerophosphate dehydrogenase. On the basis of the measured values we differ-entiated fibres in oxydative, glycolytic and oxydative-glycolytic. We found out, that MHC I are present in type I fibres (in extensor digitorum longus muscle ...
Smooth Muscle Myosin, Alexa Fluor 488, clone: SMMS-1, eBioscience™ 25μg; Alexa Fluor 488 Smooth Muscle Myosin, Alexa Fluor 488, clone: SMMS-1,...
Introduction: The extraocular muscles (EOMs) are considered a separate class of skeletal muscle, allotype. Myosin is the major contractile protein in muscle. The myosin heavy chain (MyHC) isoforms are the best molecular markers of functional heterogeneity of muscle fibers. The relaxation rate, reflects the rate at which Ca2+ is transported back into the sarcoplasmic reticulum (SR) mostly by SR Ca2+ATPase (SERCA). Myosin binding protein C (MyBP-C), plays a physiological role in regulating contraction. The laminins (Ln) are the major non-collagenous components of the basement membrane (BM) surrounding muscle fibers and are important for muscle fiber integrity.. Methods: Adult human EOMs were studied with SDS-PAGE, immunoblots and immunocytochemistry, the latter with antibodies against six MyHC, 2 SERCA, 2 MyBP-C and 8 laminin chain isoforms. The capillary density was also determined.. Results: Most fibers contained a mixture of MyHC isoforms. Three major groups of fibers could be distinguished. ...
In the present study we aimed to determine the functional properties and the myosin heavy chain (MHC) isoform composition of single chemically skinned fibres from the vocal muscle of four adult men (age: 55-67 years). Single fibres, dissected from the bioptic samples, were chemically skinned and isometric tension (P0) and maximal shortening velocity (V0) were measured at pCa 4.6. MHC and myosin light chain (MLC) composition of fibre segments and MHC distribution of the biopsy samples were analysed by SDS-poly-acrylamide gel electrophoresis (SDS-PAGE) and densitometry. Four MHC isoforms (1, 2A, 2X and a fourth isoform, provisionally called L) and five MLC isoforms (MLC1s, MLC1f, MLC3f, MLC2f, MLC2s) were identified. The major findings of this study were: (1) fast MHC isoforms (in particular MHC-2A) and fast fibres were predominant, (2) one-third of the fibres were mixed or hybrid, i.e. expressed more than one MHC isoform, (3) V0 and P0 values were determined by the MHC isoform composition and ...
Antigen Background Myosin is a contractile muscle specific protein composed of two heavy and four light chains. The myosin heavy chain has many isoforms which are specific for different muscles or fiber types, some of which are developmentally regulated. The range of myosin heavy chain antibodies may prove useful for investigating development of intrafusal and extrafusal muscle fibers and the course of muscle fiber regeneration. At the ultrastructural level, antibodies can reveal architectural details of the myofilament as well as the cytoplasmic and membrane sites of new myosin integration.. ...
Myosin light chain kinase (MLCK)-dependent phosphorylation of the regulatory light chain (RLC) of cardiac myosin is known to play a beneficial role in heart disease, but the idea of a phosphorylation-mediated reversal of a hypertrophic cardiomyopathy (HCM) phenotype is novel. Our previous studies on transgenic (Tg) HCM-RLC mice revealed that the D166V (Aspartate166 →Valine) mutation-induced changes in heart morphology and function coincided with largely reduced RLC phosphorylation in situ. In this paper, we hypothesized that the introduction of a constitutively phosphorylated Serine15 (S15D) into the hearts of D166V mice would prevent the development of a deleterious HCM phenotype. In support of this notion, MLCK-induced phosphorylation of D166V-mutated hearts was found to rescue some of their abnormal contractile properties. Tg-S15D-D166V mice were generated with the human cardiac RLC-S15D-D166V construct substituted for mouse cardiac RLC and were subjected to functional, structural, and ...
TY - JOUR. T1 - Differential Regulation of Alternatively Spliced Endothelial Cell Myosin Light Chain Kinase Isoforms by p60Src. AU - Birukov, Konstantin G.. AU - Csortos, Csilla. AU - Marzilli, Lisa. AU - Dudek, Steven. AU - Ma, Shwu Fan. AU - Bresnick, Anne R.. AU - Verin, Alexander D.. AU - Cotter, Robert J.. AU - Garcia, Joe G.N.. PY - 2001/3/16. Y1 - 2001/3/16. N2 - The Ca2+/calmodulin-dependent endothelial cell myosin light chain kinase (MLCK) triggers actomyosin contraction essential for vascular barrier regulation and leukocyte diapedesis. Two high molecular weight MLCK splice variants, EC MLCK-1 and EC MLCK-2 (210-214 kDa), in human endothelium are identical except for a deleted single exon in MLCK-2 encoding a 69-amino acid stretch (amino acids 436-505) that contains potentially important consensus sites for phosphorylation by p60Src kinase (Lazar, V., and Garcia, J. G. (1999) Genomics 57, 256-267). We have now found that both recombinant EC MLCK splice variants exhibit comparable ...
TY - JOUR. T1 - Myosin V walks hand-over-hand. T2 - Single fluorophore imaging with 1.5-nm localization. AU - Yildiz, Ahmet. AU - Forkey, Joseph N.. AU - McKinney, Sean A.. AU - Ha, Taekjip. AU - Goldman, Yale E.. AU - Selvin, Paul R.. PY - 2003/6/27. Y1 - 2003/6/27. N2 - Myosin V is a dimeric molecular motor that moves processively on actin, with the center of mass moving ±37 nanometers for each adenosine triphosphate hydrolyzed. We have labeled myosin V with a single fluorophore at different positions in the light-chain domain and measured the step size with a standard deviation of ,1.5 nanometers, with 0.5-second temporal resolution, and observation times of minutes. The step size alternates between 37 + 2x nm and 37 - 2x, where x is the distance along the direction of motion between the dye and the midpoint between the two heads. These results strongly support a hand-over-hand model of motility, not an inchworm model.. AB - Myosin V is a dimeric molecular motor that moves processively on ...
Background: Reversible lysine-acetylation of proteins is regulated by histone acetyl transferases and deacetylases (HDACs). Previous studies from this laboratory have shown that a class-II HDAC, HDAC4 is associated with cardiac sarcomeres, and that HDAC-inhibitors enhance the contractile activity of myofilaments. Since, HDAC4 has little or no deacetylase activity of its own, this study was undertaken to examine the presence of other HDACs on cardiac sarcomeres.. Methods and Results: We prepared skinned papillary muscle fibers of the mouse heart and subjected them to western analysis. Results showed that a class-I HDAC, HDAC3 was localized to cardiac sarcomeres. By immuno-histochemical and electron microscopic analyses we found that HDAC3 was localized to the A-band of cardiac sarcomeres. We therefore examined the reversible acetylation of the A-band protein, myosin heavy chains (MHCs). MHC isoforms were prepared from control and PTU-treated mice, and examined for acetylation by western analysis ...
Myosin light chain kinase (MLCK) induces contraction of the perijunctional apical actomyosin ring in response to phosphorylation of the myosin light chain. Abnormal expression of MLCK has been observed in respiratory diseases, pancreatitis, cardiovascular diseases, cancer, and inflammatory bowel disease (IBD). The signaling pathways involved in MLCK activation and triggering of endothelial barrier dysfunction are discussed in this review. The pharmacological effects of regulating MLCK expression by inhibitors such as ML-9, ML-7, microbial products, naturally occurring products, and microRNAs are also discussed. The influence of MLCK in inflammatory diseases starts with endothelial barrier dysfunction. The effectiveness of anti-MLCK treatment may depend on alleviation of that primary pathological mechanism. This review summarizes evidence for the potential benefits of anti-MLCK agents in the treatment of inflammatory disease and the importance of avoiding treatment-related side effects, as MLCK is widely
Browsing Doctoral Degrees (Molecular Biology and Human Genetics) by Title An investigation of myosin binding protein C mutations in South Africa and a search for ligands binding to myosin binding protein C ...
We observed the localization of the contractile proteins myosin, filamentous actin, alpha-actinin, tropomyosin, and vinculin in surface-activated, spreading human platelets using a single fluorescence staining procedure and conventional fluorescence microscopy. Myosin was distributed in a speckled pattern that extended radially from the granulomere. F-actin demonstrated cable-networks. Tropomyosin and alpha-actinin occurred in a punctuate distribution, and vinculin was localized at adhesion sites. Although myosin, F-actin, alpha-actinin, tropomyosin, and vinculin were not studied in resting platelets, our data support the idea that these contractile proteins are reorganized and reassembled in activated platelets during platelet function.
TY - JOUR. T1 - Functional and biophysical analyses of the class XIV Toxoplasma gondii Myosin D. AU - Herm-Götz, Angelika. AU - Delbac, Frêdêric. AU - Weiss, Stefan. AU - Nyitrai, Miklos. AU - Stratmann, Rolf. AU - Tomavo, Stanislas. AU - Sibley, L. David. AU - Geeves, Michael A.. AU - Soldati, Dominique. PY - 2006/2/1. Y1 - 2006/2/1. N2 - The obligate intracellular parasite Toxoplasma gondii uses gliding motility to migrate across the biological barriers of the host and to invade cells. This unique form of locomotion requires an intact actin cytoskeleton and involves at least one motor protein (TgMyoA) that belongs to the class XIV of the myosin superfamily. TgMyoA is anchored in the inner membrane complex and is essential for the gliding motion, host cell invasion and egress of T. gondii tachyzoites. TgMyoD is the smallest T. gondii myosin and is structurally very closely related to TgMyoA. We show here that TgMyoD exhibits similar transient kinetic properties as the fast single-headed ...
Purpose: Aging is associated with a decline in muscle volume, power output, and the velocity at which peak power (Vopt) occurs. The current study aimed to examine the relationship between lower-limb power output characteristics, muscle myosin heavy chain (MHC) composition, and lean limb volume. Methods: Lower-limb power output during repeated efforts on an inertial sprint cycle and single-leg thrusts on the modified Nottingham power rig was studied in seven young and seven old males in relation to muscle MHC isoform composition of the vastus lateralis. Results: Older subjects produced significantly lower power outputs and Vopt under all conditions (P , 0.01) and had lower proportions of fast MHC isoforms (P , 0.05). Peak power output during cycling was significantly related to lower-limb lean volume (r = 0.92, P , 0.05), whereas Vopt during sprint cycling was closely related to vastus lateralis MHC-II composition (r = 0.80, P , 0.05). Conclusions: These results provide further evidence of the ...
In order to understand the mechanism of defective myofibrilogenesis in muscular dystrophy, we have used the genomic cloned DNA specific for myosin light chain 2A (MLC 2A) to check its expression. The fusion of a partial digest of λLC5, containing the upstream sequence of MLC 2A gene with the expression vector of Psvocat has already been reported. Using this CAT-fused recombinant containing 1.6 kb of MLC 2A gene, we were able to detect the promoter activity in normal heart cells, H9C2 cell line whereas a restricted expression of MLC 2A gene was noticed in muscular dystrophic muscle cells from heart and skeletal. We have also measured the transient transfection efficiency by contransfecting with the plasmid LacZ. Simultaneous assay of β-galactosidase and CAT in the cell extract was performed. With β-galactosidase as control, we confirmed that the promoter activity of MLC 2A gene is inhibited in muscular dystrophy though there is a normal rate of transfection occurred. ...
Familial hypertrophic cardiomyopathy (HCM) is caused by mutations in 9 sarcomeric protein genes. The most commonly affected is beta-myosin heavy chain (MYH7), where missense mutations cluster in the head and neck regions and directly affect motor function. Comparable mutations have not been described in the light meromyosin (LMM) region of the myosin rod, nor would these be expected to directly affect motor function. We studied 82 probands with HCM in whom no mutations had been found in MYH7 exons encoding the head and neck regions of myosin nor in the other frequently implicated disease genes. Primers were designed to amplify exons 24 to 40 of MYH7. These amplimers were subjected to temperature modulated heteroduplex analysis by denaturing high-performance liquid chromatography. An Ala1379Thr missense mutation in exon 30 segregated with disease in three families and was not present in 200 normal chromosomes. The mutation occurred on two haplotypes, indicating that it was not a polymorphism linked with
Blebbistatin inhibits myosin ATPase activity and this way acto-myosin based motility. It binds halfway between the nucleotide binding pocket and the actin binding cleft of myosin, predominantly in an actin detached conformation.[10] This type of inhibition relaxes the acto-myosin myofilaments and leads to several biological effects. Blebbistatin inhibits the formation of blebs in melanoma cell culture,[11] hence its name. At a cellular level, blebbistatin also inhibits cytokinesis [11] and may also disrupt mitotic spindle formation.[12] Migration of cells can be either enhanced or inhibited depending on other conditions.[13] In neurons, blebbistatin was found to promote neurite outgrowth.[14] At the organ level blebbistatin stops the contraction of skeletal muscle [15] or heart muscle.[16] Blebbistatin has also been found to stabilize the super relaxed state in the myofilaments, where myosin heads are in a helical order and interact with each other but not with actin.[17][18][19] ...
Filament assembly of nonmuscle myosin IIA (NMIIA) is selectively regulated by the small Ca²⁺-binding protein, S100A4, which causes enhanced cell migration and metastasis in certain cancers. Our NMR structure shows that an S100A4 dimer binds to a single myosin heavy chain in an asymmetrical configuration. NMIIA in the complex forms a continuous helix that stretches across the surface of S100A4 and engages the Ca²⁺-dependent binding sites of each subunit in the dimer. Synergy between these sites leads to a very tight association (K(D) ∼1 nM) that is unique in the S100 family. Single-residue mutations that remove this synergy weaken binding and ameliorate the effects of S100A4 on NMIIA filament assembly and cell spreading in A431 human epithelial carcinoma cells. We propose a model for NMIIA filament disassembly by S100A4 in which initial binding to the unstructured NMIIA tail initiates unzipping of the coiled coil and disruption of filament packing.. ...
Purpose: : Defects in the gene encoding for myosin VIIa (myo7a) cause Usher syndrome 1B and affected patients suffer of deafness, vestibular dysfunction, and blindness. Myo7a is expressed in inner hair cells, retinal photoreceptors, and in the retinal pigment epithelium. Here, we characterize the retinal phenotype of 3 different myo7a alleles in the mutant zebrafish mariner. Methods: : We examined light and dark adapted mutant larvae of the different affected alleles (mar ty220d, tc320b, tr202) at different developmental stages. The morphology of dark / light adapted, and light damaged retinas was assessed by standard histology and electron microscopy. Immunocytochemistry was used to identify subpopulations of retinal neurons and to localize myosin VIIa in the zebrafish retina. Furthermore, the optokinetic response (OKR) was used to analyze light adaptation defects, and electroretinogramms (ERGs) were measured to compare mutant and wt retinal functionality. Results: : ERGs reveal reduced b-waves ...
Catalytic domain of the Protein Serine/Threonine Kinase, Class IIIA myosin. Serine/threonine kinases (STKs), class IIIA myosin subfamily, catalytic (c) domain. STKs catalyze the transfer of the gamma-phosphoryl group from ATP to serine/threonine residues on protein substrates. The class III myosin subfamily is part of a larger superfamily that includes the catalytic domains of other protein STKs, protein tyrosine kinases, RIO kinases, aminoglycoside phosphotransferase, choline kinase, and phosphoinositide 3-kinase. Class III myosins are motor proteins containing an N-terminal kinase catalytic domain and a C-terminal actin-binding domain. Class III myosins may play an important role in maintaining the structural integrity of photoreceptor cell microvilli. In photoreceptor cells, they may also function as cargo carriers during light-dependent translocation of proteins such as transducin and arrestin. Class IIIA myosin is highly expressed in retina and in inner ear hair cells. It is localized to ...
Catalytic domain of the Protein Serine/Threonine Kinase, Class IIIB myosin. Serine/threonine kinases (STKs), class IIIB myosin subfamily, catalytic (c) domain. STKs catalyze the transfer of the gamma-phosphoryl group from ATP to serine/threonine residues on protein substrates. The class III myosin subfamily is part of a larger superfamily that includes the catalytic domains of other protein STKs, protein tyrosine kinases, RIO kinases, aminoglycoside phosphotransferase, choline kinase, and phosphoinositide 3-kinase. Class III myosins are motor proteins containing an N-terminal kinase catalytic domain and a C-terminal actin-binding domain. Class III myosins may play an important role in maintaining the structural integrity of photoreceptor cell microvilli. They may also function as cargo carriers during light-dependent translocation, in photoreceptor cells, of proteins such as transducin and arrestin. Class IIIB myosin is expressed highly in retina. It is also present in the brain and testis. The ...
non-muscle Myosin IIB小鼠单克隆抗体[3H2](ab684)可与小鼠, 大鼠, 兔, 仓鼠, 人样本反应并经WB, IHC, Flow Cyt, ICC/IF实验严格验证,被13篇文献引用并得到5个独立的用户反馈。
TY - JOUR. T1 - The occurrence of myosin light chain kinase in non-muscle tissues. AU - Miyamoto, E.. AU - Matsui, K.. AU - Fukunaga, K.. PY - 1981/1/1. Y1 - 1981/1/1. UR - http://www.scopus.com/inward/record.url?scp=0019412942&partnerID=8YFLogxK. UR - http://www.scopus.com/inward/citedby.url?scp=0019412942&partnerID=8YFLogxK. U2 - 10.2220/biomedres.2.341. DO - 10.2220/biomedres.2.341. M3 - Article. AN - SCOPUS:0019412942. VL - 2. SP - 341. EP - 346. JO - Biomedical Research (Japan). JF - Biomedical Research (Japan). SN - 0388-6107. IS - 3. ER - ...
TY - JOUR. T1 - Phosphorylation of MYPT1 by protein kinase C attenuates interaction with PP1 catalytic subunit and the 20 kDa light chain of myosin. AU - Tóth, Attila. AU - Kiss, Enikö. AU - Gergely, P.. AU - Walsh, Michael P.. AU - Hartshorne, David J.. AU - Erdődi, F.. PY - 2000/11/3. Y1 - 2000/11/3. N2 - The effect of phosphorylation in the N-terminal region of myosin phosphatase target subunit 1 (MYPT1) on the interactions with protein phosphatase 1 catalytic subunit (PP1c) and with phosphorylated 20 kDa myosin light chain (P-MLC20) was studied. Protein kinase C (PKC) phosphorylated threonine-34 (1 mol/mol), the residue preceding the consensus PP1c-binding motif (35KVKF38) in MYPT11-38, but this did not affect binding of the peptide to PP1c. PKC incorporated 2 mol P(i) into MYPT11-296 suggesting a second site of phosphorylation within the ankyrin repeats (residues 40-296). This phosphorylation diminished the stimulatory effect of MYPT11-296 on the P-MLC20 phosphatase activity of PP1c. ...
calmodulin-dependent protein kinase activity, myosin light chain kinase activity, structural constituent of cytoskeleton, protein phosphorylation
Circular RNA Myosin Light Chain Kinase (MYLK) Promotes Prostate Cancer Progression through Modulating Mir-29a Expression - Article statistics #908009
TY - JOUR. T1 - Monitoring the Myosin Crossbridge Cycle in Contracting Muscle. T2 - Steps towards Muscle the Movie.. AU - Eakins, Felicity. AU - Knupp, Carlo. AU - Squire, John M. PY - 2019/7/20. Y1 - 2019/7/20. N2 - Some vertebrate muscles (e.g. those in bony fsh) have a simple lattice A-band which is so well ordered that low-angle X-ray difraction patterns are sampled in a simple way amenable to crystallographic techniques. Time-resolved X-ray diffraction through the contractile cycle should provide a movie of the molecular movements involved in muscle contraction. Generation of Muscle-The Movie was suggested in the 1990s and since then eforts have been made to work out how to achieve it. Here we discuss how a movie can be generated, we discuss the problems and opportunities, and present some new observations. Low angle X-ray difraction patterns from bony fsh muscles show myosin layer lines that are well sampled on row-lines expected from the simple hexagonal A-band lattice. The 1st, 2nd ...
Tropomyosin is a rod-shaped molecule composed of two intertwined polypeptides with a length approximately equal to that of seven actin molecules. Chains of tropomyosin molecules are arranged end to end along the actin thin filament. These tropomyosin molecules partially cover the myosin-binding site on each actin molecule, thereby preventing the cross-bridges from making contact with actin. Each tropomyosin molecule is held in this blocking position by troponin, a smaller, globular protein that is bound to both tropomyosin and actin. One molecule of troponin binds to each molecule of tropomyosin and regulates the access to myosin-binding sites on the seven actin molecules in contact with tropomyosin. This is the status of a resting muscle fiber; troponin and tropomyosin cooperatively block the interaction of cross-bridges with the thin filament. ...
Description: Enzyme-linked immunosorbent assay based on the Double-antibody Sandwich method for detection of Mouse Myosin Binding Protein C, Slow Type (MYBPC1) in samples from Serum, plasma, tissue homogenates and other biological fluids. with no significant corss-reactivity with analogues from other species ...
TY - JOUR. T1 - Loss of myosin Vb promotes apical bulk endocytosis in neonatal enterocytes. AU - Engevik, Amy C.. AU - Kaji, Izumi. AU - Postema, Meagan M.. AU - Faust, James J.. AU - Meyer, Anne R.. AU - Williams, Janice A.. AU - Fitz, Gillian N.. AU - Tyska, Matthew J.. AU - Wilson, Jean M.. AU - Goldenring, James R.. PY - 2019/11/4. Y1 - 2019/11/4. N2 - In patients with inactivating mutations in myosin Vb (Myo5B), enterocytes show large inclusions lined by microvilli. The origin of inclusions in small-intestinal enterocytes in microvillus inclusion disease is currently unclear. We postulated that inclusions in Myo5b KO mouse enterocytes form through invagination of the apical brush border membrane. 70-kD FITC-dextran added apically to Myo5b KO intestinal explants accumulated in intracellular inclusions. Live imaging of Myo5b KO-derived enteroids confirmed the formation of inclusions from the apical membrane. Treatment of intestinal explants and enteroids with Dyngo resulted in accumulation of ...
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INTRODUCTION. Muscle fibers and extracellular intramuscular connective tissue are the main components of skeletal striated muscle. In order to identify types of fibers, the enzymatic activity is one of the characteristics that had permitted to classify myocytes according to their metabolism (oxidative, intermediate and glycolytic), velocity of contraction (slow twitch fibers, intermediate fibers and fast twitch fibers) and to molecular level, isoforms of myosin heavy chain (MHC-1, MHC-IIA, MCHIIB) (Purslow, 2010; de Freitas et al., 2009; Scott et al., 2001). Enzyme histochemistry techniques such as mATPase (myosin adenosine triphosphatase) and NADH-TR (nicotinamide adenine dinucleotide tetrazolium reductase), indicate in striated skeletal muscle tissue, fast twitch fibers that are associated with glycolytic and glycolytic-intermediate metabolism, while slow twitch fibers with oxidative metabolism (Vivo et al., 2004; Hebling et al., 2006; Carmo-Araújo et al., 2007; de Freitas et al.).. Modern ...
Myofiber growth and myofibril assembly at the myotendinous junction (MTJ) of stretch-hypertrophied rabbit skeletal muscle was studied by in situ hybridization, immunofluorescence, and electron microscopy. In situ hybridization identified higher levels of myosin heavy chain (MHC) mRNA at the MTJ of fibers stretched for 4 d. Electron microscopy at the MTJ of these lengthening fibers revealed a large cytoplasmic space devoid of myofibrils, but containing polysomes, sarcoplasmic reticulum and T-membranes, mitochondria, Golgi complexes, and nascent filament assemblies. Tallies from electron micrographs indicate that myofibril assembly in stretched fibers followed a set sequence of events. (a) In stretched fiber ends almost the entire sarcolemmal membrane was electron dense but only a portion had attached myofibrils. Vinculin, detected by immunofluorescence, was greatly increased at the MTJ membrane of stretched muscles. (b) Thin filaments were anchored to the sarcolemma at the electron dense sites. ...