We report the identification and characterization of myr 4 (myosin from rat), the first mammalian myosin I that is not closely related to brush border myosin I. Myr 4 contains a myosin head (motor) domain, a regulatory domain with light chain binding sites and a tail domain. Sequence analysis of myosin I head (motor) domains suggested that myr 4 defines a novel subclass of myosin Is. This subclass is clearly different from the vertebrate brush border myosin I subclass (which includes myr 1) and the myosin I subclass(es) identified from Acanthamoeba castellanii and Dictyostelium discoideum. In accordance with this notion, a detailed sequence analysis of all myosin I tail domains revealed that the myr 4 tail is unique, except for a newly identified myosin I tail homology motif detected in all myosin I tail sequences. The Ca(2+)-binding protein calmodulin was demonstrated to be associated with myr 4. Calmodulin binding activity of myr 4 was mapped by gel overlay assays to the two consecutive light ...

Myosins are actin-based motor proteins involved in many cellular movements. It is interesting to study the evolutionary patterns and the functional attributes of various types of myosins. Computational search algorithms were performed to identify putative myosin members by phylogenetic analysis, sequence motifs, and coexisting domains. This study is aimed at understanding the distribution and the likely biological functions of myosins encoded in various taxa and available eukaryotic genomes. We report here a phylogenetic analysis of around 4,064 myosin motor domains, built entirely from complete or near-complete myosin repertoires incorporating many unclassified, uncharacterized sequences and new myosin classes, with emphasis on myosins from Fungi, Haptophyta, and other Stramenopiles, Alveolates, and Rhizaria (SAR). The identification of large classes of myosins in Oomycetes, Cellular slime molds, Choanoflagellates, Pelagophytes, Eustigmatophyceae, Fonticula, Eucoccidiorida, and Apicomplexans ...

Conventional myosin (myosin II) is a major component of the cytoskeleton in a wide variety of eukaryotic cells, ranging from lower amoebae to mammalian fibroblasts and neutrophils. Gene targeting technologies available in the Dictyostelium discoideum system have provided the first genetic proof that this molecular motor protein is essential for normal cytokinesis, capping of cell surface receptors, normal chemotactic cell locomotion and morphogenetic shape changes during development. Although the roles of myosin in a variety of cell functions are becoming clear, the mechanisms that regulate myosin assembly into functional bipolar filaments within cells are poorly understood. Dictyostelium is currently the only system where mutant forms of myosin can be engineered in vitro, then expressed in their native context in cells that are devoid of the wild-type isoform. We have utilized this technology in combination with nested truncation and deletion analysis to map domains of the myosin tail ...

Using optical trapping and fluorescence imaging techniques, we measured the step size and stiffness of single skeletal myosins interacting with actin filaments and arranged on myosin-rod cofilaments that approximate myosin mechanics during muscle contraction. Stiffness is dramatically lower for negatively compared to positively strained myosins, consistent with buckling of myosins subfragment 2 rod domain. Low stiffness minimizes drag of negatively strained myosins during contraction at loaded conditions. Myosins elastic portion is stretched during active force generation, reducing apparent step size with increasing load, even though the working stroke is approximately constant at about 8 nanometers. Taking account of the nonlinear nature of myosin elasticity is essential to relate myosins internal structural changes to physiological force generation and filament sliding.. ...

TY - JOUR. T1 - High-performance ion-exchange chromatography of myosin using a DEAE-5PW column. AU - Lema, Mark J.. AU - Pluskal, Malcolm G.. AU - Allen, Paul D.. PY - 1989. Y1 - 1989. N2 - High-performance ion-exchange chromatography of myosin using a DEAE-5PW packing was used to purify myosin from skeletal, cardiac and smooth muscle. This method produces high-speed resolution (30-min analysis) of myosin from contaminating myofibrillar proteins. The column has a high capacity for binding myosin (up to 1 g) and can be used for small-scale preparation of highly purified myosin. Gel analysis in the presence of sodium dodecyl sulfate showed recovery of myosin with very little contamination of other myofibrillar proteins. Myosin was also recovered from small biopsy samples (0.1 g) by a direct extraction technique with recovery of biological ATPase activity.. AB - High-performance ion-exchange chromatography of myosin using a DEAE-5PW packing was used to purify myosin from skeletal, cardiac and ...

The docking of the heads onto the thick filament backbone may be directly relevant to the physiology of how muscles most efficiently maintain the relaxed state (2, 3). Several published three-dimensional (3D) reconstructions of relaxed myosin thick filaments (4-8) indicate that the heads are docked in an asymmetric structure known as the interacting heads motif (IHM) (Fig. 1D). The IHM was first observed in smooth muscle myosin and explained how smooth muscle myosin is switched on and off by phosphorylation (9). In the IHM, one head is called blocked because its actin-binding domain contacts the adjacent head and is therefore unavailable to bind actin. The other head is called free because its actin-binding domain is not obstructed and could theoretically bind actin. The IHM was originally thought to be specific to smooth and nonmuscle myosin but was later observed in thick filaments from tarantula (4, 10), scallop (8), Limulus (5), and human cardiac muscle (6, 7), leading to the suggestions ...

Muscle, motor unit and muscle fibre type-specific differences in force-generating capacity have been investigated for many years, but there is still no consensus regarding specific differences between slow- and fast-twitch muscles, motor units or muscle fibres. This is probably related to a number of different confounding factors disguising the function of the molecular motor protein myosin. We have therefore studied the force-generating capacity of specific myosin isoforms or combination of isoforms extracted from short single human muscle fibre segments in a modified single fibre myosin in vitro motility assay, in which an internal load (actin-binding protein) was added in different concentrations to evaluate the force-generating capacity. The force indices were the x-axis intercept and the slope of the relationship between the fraction of moving filaments and the α-actinin concentration. The force-generating capacity of the β/slow myosin isoform (type I) was weaker (P , 0.05) than the fast ...

Caldesmon interaction with smooth muscle myosin and its ability to cross-link actin filaments to myosin were investigated by the use of several bacterially expressed myosin-binding fragments of caldesmon. We have confirmed the presence of two functionally different myosin-binding sites located in domains 1 and 3/4a of caldesmon. The binding of the C-terminal site is highly sensitive to ionic strength and hardly participates in acto-myosin cross-linking, while the N-terminal binding site is relatively independent of ionic strength and apparently contains two separate myosin contact regions within residues 1-28 and 29-128 of chicken gizzard caldesmon. Both these N-terminal sub-sites are involved in the interaction with myosin and are predominantly responsible for the caldesmon-mediated high-affinity cross-linking of actin and myosin filaments, without affecting the affinity of direct acto-myosin interaction. Binding of caldesmon and its fragments to myosin or rod filaments revealed affinity in the ...

Mts1 protein (S100A4 according to a new classification) has been implicated in the formation of the metastatic phenotype via regulation of cell motility and invasiveness. Previously we have demonstrated that Mts1 protein interacted with the heavy chain of nonmuscle myosin in a calcium- dependent manner. To elucidate the role of the Mts1-myosin interaction, we mapped the Mts1-binding region on the myosin heavy chain molecule. We prepared proteolytically digested platelet myosin and a series of overlapped myosin heavy chain protein fragments and used them in a blot overlay with Mts1 protein. Here we report that the Mts1-binding site is located within a 29-amino acid region, at the C-terminal end of the myosin heavy chain (between 1909-1937 amino acids). Two-dimensional phosphopeptide analysis showed that Mts1 protein inhibits protein kinase C phosphorylation of the platelet myosin heavy chain at Ser-1917. We hypothesize that Mts1 protein regulates cytoskeletal dynamics of the metastatic cells ...

Myosin Protein is the most advanced, synergistic blend of the highest quality protein powders, peptides and amino acids on the market today. It contains the precise amino acid mix to maximize protein synthesis, decrease muscle breakdown and enhance athletic performance.. Myosin Protein, with its combination of fast and slow proteins and peptides, is specially engineered to provide several anabolic amino acid peak bursts that result in an immediate and several intermediate marked increases in serum amino acids and subsequently protein synthesis. As well, Myosin Protein provides a long term steady increase in serum amino acid levels that lasts for several hours and has been shown to have marked anticatabolic effects.. The bottom line is that Myosin Protein Complex is the most advanced, synergistic blend of the highest quality proteins, peptides and amino acids on the market today, bar none. It contains an optimized protein/peptide/amino acid mix that maximizes protein synthesis and muscle mass, ...

Contractile agonists can mobilize Ca2+ from both intracellular and extracellular stores in smooth muscle. This study addresses the role of Ca2+ mobilization as it relates to the complex manner by which Ca2+ regulates the contractile system in smooth muscle. In swine carotid media, both histamine and phenylephrine produced initial rapid increases in myosin phosphorylation and stress. Stress was sustained for the duration of the stimulus while myosin phosphorylation slowly declined to steady-state levels. Removal of extracellular Ca2+ or elimination of cellular Ca2+ influx did not dramatically reduce the initial rapid increase in myosin phosphorylation produced by either agonist but reduced steady-state levels of myosin phosphorylation to basal values. Initial rapid increases in stress were seen, but stress was not maintained. Following depletion of Ca2+ from sarcoplasmic reticulum, muscle activation by Ca2+ influx in the presence of phenylephrine occurred without an initial transient in myosin ...

TY - JOUR. T1 - Characterization of myosin V binding to brain vesicles. AU - Miller, Kyle E.. AU - Sheetz, Michael. PY - 2000/1/28. Y1 - 2000/1/28. N2 - Myosin II and V are important for the generation and segregation of subcellular compartments. We observed that vesicular myosin II and V were associated with the protein scaffolding of a common subset of vesicles by density sedimentation, electron microscopy, and immunofluorescence. Solubilization of either myosin II or V was caused by polyphosphates with the following efficacy at 10 mM: for myosin II ATP-Mg2+ = ATP = AMP-PNP (5- adenylyl imidodiphosphate) , pyrophosphate = tripolyphosphate ,, tetrapolyphosphate = ADP , cAMP = Mg2+; and for myosin V pyrophosphate = tripolyphosphate , ATP-Mg2+ = ATP = AMP-PNP ,, ADP = tetrapolyphosphate , cAMP = Mg2+. Consequently, we suggest solubilization was not an effect of phosphorylation, hydrolysis, or disassociation of myosin from actin filaments. Scatchard analysis of myosin V binding to stripped dense ...

1. Combined histochemical and biochemical single-fibre analyses [Staron & Pette (1987) Biochem. J. 243, 687-693], were used to investigate the rabbit tibialis-anterior fibre population. 2. This muscle is composed of four histochemically defined fibre types (I, IIC, IIA and IIB). 3. Type I fibres contain slow myosin light chains LC1s and LC2 and the slow myosin heavy chain HCI, and types IIA and IIB contain the fast myosin light chains LC1f, LC2f and LC3f and the fast heavy chains HCIIa and HCIIb respectively. 4. A small fraction of fibres (IIAB), histochemically intermediate between types IIA and IIB, contain the fast light myosin chains but display a coexistence of HCIIa and HCIIb. 5. Similarly to the soleus muscle, C fibres in the tibialis anterior muscle contain both fast and slow myosin light chains and heavy chains. The IIC fibres show a predominance of the fast forms and the IC fibres (histochemically intermediate between types I and IIC) a predominance of the slow forms. 6. A total of 60 ...

Title: Regulatory Light Chains of Striated Muscle Myosin. Structure, Function and Malfunction. VOLUME: 3 ISSUE: 2. Author(s):Danuta Szczesna-Cordary. Affiliation:Department of Molecular&Cellular Pharmacology, University of Miami School of MedicineRosenstiel Medical Sciences Building R-189, Room 6113, USA. Keywords:regulatory light chains of myosin (rlc), Phosphorylation, skinned fibers, familial hypertrophic, cardiomyopathy (fhc) mutations.. Abstract: Striated (skeletal and cardiac) muscle is activated by the binding of Ca2+ to troponin C and is regulated by the thin filament proteins, tropomyosin and troponin. Unlike in molluscan or smooth muscles, the myosin regulatory light chains (RLC) of striated muscles do not play a major regulatory role and their function is still not well understood. The N-terminal domain of RLC contains a Ca2+-Mg2+-binding site and, analogous to that of smooth muscle myosin, also contains a phosphorylation site. During muscle contraction, the increase in Ca2+ ...

TY - JOUR. T1 - Ca2+, cAMP, and changes in myosin phosphorylation during contraction of smooth muscle. AU - Aksoy, M. O.. AU - Mras, S.. AU - Kamm, K. E.. AU - Murphy, R. A.. PY - 1983. Y1 - 1983. N2 - Phosphorylation of myosin increases rapidly upon stimulation of an arterial smooth muscle. However, peak values are not maintained and phosphorylation declines, while active stress increases monotonically to a sustained steady state. The aim of this study was to determine the reason(s) for the transient change in myosin phosphorylation. Four hypotheses were considered: 1) reduced substrate, i.e., ATP depletion, 2) altered access of either the myosin kinase or phosphatase to the cross bridge, 3) reduced myosin kinase activity secondary to its phosphorylation by adenosine 3,5-cyclic monophosphate-dependent protein kinase, and 4) reduced myoplasmic [Ca2+] during the contraction. Our results suggest that the most likely explanation is that there are two Ca2+-dependent regulatory processes: 1) myosin ...

Antibodies with epitopes near the heavy meromyosin/light meromyosin junction distinguish the folded from the extended conformational states of smooth muscle myosin. Antibody 10S.1 has 100-fold higher avidity for folded than for extended myosin, while antibody S2.2 binds preferentially to the extended state. The properties of these antibodies provide direct evidence that the conformation of the rod is different in the folded than the extended monomeric state, and suggest that this perturbation may extend into the subfragment 2 region of the rod. Two antihead antibodies with epitopes on the heavy chain map at or near the head/rod junction. Magnesium greatly enhances the binding of these antibodies to myosin, showing that the conformation of the heavy chain in the neck region changes upon divalent cation binding to the regulatory light chain. Myosin assembly is also altered by antibody binding. Antibodies that bind to the central region of the rod block disassembly of filaments upon MgATP addition. ...

The global cell movements that shape an embryo are driven by intricate changes to the cytoarchitecture of individual cells. In a developing embryo, these changes are controlled by patterning genes that confer cell identity. However, little is known about how patterning genes influence cytoarchitecture to drive changes in cell shape. In this paper, we analyze the function of the folded gastrulation gene (fog), a known target of the patterning gene twist. Our analysis of fog function therefore illuminates a molecular pathway spanning all the way from patterning gene to physical change in cell shape. We show that secretion of Fog protein is apically polarized, making this the earliest polarized component of a pathway that ultimately drives myosin to the apical side of the cell. We demonstrate that fog is both necessary and sufficient to drive apical myosin localization through a mechanism involving activation of myosin contractility with actin. We determine that this contractility driven form of ...

In smooth muscle cells (SMCs) isolated from rabbit carotid, femoral, and saphenous arteries, relative myosin isoform mRNA levels were measured in RT-PCR to test for correlations between myosin isoform expression and unloaded shortening velocity. Unloaded shortening velocity and percent smooth muscle myosin heavy chain 2 (SM2) and myosin light chain 17b (MLC17b) mRNA levels were not significantly different in single SMCs isolated from the luminal and adluminal regions of the carotid media. Saphenous artery SMCs shortened significantly faster (P | 0.05) than femoral SMCs and had more SM2 mRNA (P | 0.05) than carotid SMCs and less MLC17b mRNA (P | 0.001) and higher tissue levels of SMB mRNA (P | 0.05) than carotid and femoral SMCs. No correlations were found between percent SM2 and percent MLC17b mRNA levels and unloaded shortening velocity in SMCs from these arteries. We have previously shown that myosin heavy chain (MHC) SM1/SM2 and SMA/SMB and MLC17a/MLC17b isoform mRNA levels correlate with protein

TY - JOUR. T1 - Analysis of stress in the active site of myosin accompanied by conformational changes in transient state intermediate complexes using photoaffinity labeling and 19F-NMR spectroscopy. AU - Maruta, Shinsaku. AU - Henry, Gillian D.. AU - Ohki, Takashi. AU - Kambara, Taketoshi. AU - Sykes, Brian D.. AU - Ikebe, Mitsuo. PY - 1998/3/15. Y1 - 1998/3/15. N2 - Myosin forms stable ternary complexes with ADP and the phosphate analogues, fluoroaluminate (Al F4/-), fluoroberyllate (BeF(n)) or orthovanadate (Vi); these ternary complexes mimic transient intermediates in the myosin ATPase cycle. Moreover, we previously demonstrated that these complexes may mimic different myosin ATPase reaction intermediates corresponding to separate steps in the cross-bridge cycle [Maruta, S., Henry, G. D., Sykes, B. D. and Ikebe, M. (1993) J. Biol. Chem. 268, 7093-7100]. Park et al. suggested that the changing conformation of ATP during hydrolysis stresses the active site of myosin subfragment-1 (S-1) through ...

The last eukaryotic common ancestor already had an amazingly complex cell possessing genomic and cellular features such as spliceosomal introns, mitochondria, cilia-dependent motility, and a cytoskeleton together with several intracellular transport systems. In contrast to the microtubule-based dyneins and kinesins, the actin-filament associated myosins are considerably divergent in extant eukaryotes and a unifying picture of their evolution has not yet emerged. Here, we manually assembled and annotated 7852 myosins from 929 eukaryotes providing an unprecedented dense sequence and taxonomic sampling. For classification we complemented phylogenetic analyses with gene structure comparisons resulting in 79 distinct myosin classes. The intron pattern analysis and the taxonomic distribution of the classes suggest two myosins in the last eukaryotic common ancestor, a class-1 prototype and another myosin, which is most likely the ancestor of all other myosin classes. The sparse distribution of class-2 and

Although cytoskeletal proteins such as myosin II are implicated in the control of insulin secretion, their precise role is poorly understood. In other secretory cells, myosin II is predominantly regulated via the phosphorylation of the regulatory light chains (RLC). The current study was aimed at investigating RLC phosphorylation in beta-cells. In both the insulin-secreting cell line RINm5F and rat pancreatic islets, the RLC was basally phosphorylated on the myosin light chain kinase sites (Ser19/Thr18). Phosphorylation at these sites was not consistently increased by either metabolic stimuli (glyceraldehyde/glucose) or the depolarizing agent KCl. The RLC sites phosphorylated by protein kinase C (PKC) (Ser1/Ser2) were unphosphorylated in the basal state, not affected by nutrients or KCl, and only slightly increased by the PKC activator phorbol 12-myristate 13-acetate (PMA). Like the other insulin secretagogues, however, PMA did promote serine phosphorylation of the myosin heavy chain (MHC) in RINm5F

Centrosomes are the main microtubule (MT)-organizing centers in animal cells, but they also influence the actin/myosin cytoskeleton. The Drosophila CP190 protein is nuclear in interphase, interacts with centrosomes during mitosis, and binds to MTs directly in vitro. CP190 has an essential function in the nucleus as a chromatin insulator, but centrosomes and MTs appear unperturbed in Cp190 mutants. Thus, the centrosomal function of CP190, if any, is unclear. Here, we examine the function of CP190 in Cp190 mutant germline clone embryos. Mitosis is not perturbed in these embryos, but they fail in axial expansion, an actin/myosin-dependent process that distributes the nuclei along the anterior-to-posterior axis of the embryo. Myosin organization is disrupted in these embryos, but actin appears unaffected. Moreover, a constitutively activated form of the myosin regulatory light chain can rescue the axial expansion defect in mutant embryos, suggesting that CP190 acts upstream of myosin activation. A CP190

There are no specific protocols for Anti-Myosin Phosphatase 1+Myosin Phosphatase 2 antibody [YE336] (ab32519). Please download our general protocols booklet

Arterial vascular smooth muscle cells (VSMCs) play an important role in the function of many organ systems. Abnormality in the contractile and/or regulatory apparatus of smooth muscle is implicated in the pathogenesis of a variety of disease conditions such as hypertension, coronary and cerebral vasospasm, miscarriage, and erectile dysfunction. VSMCs in vivo show remarkable plasticity once they need to adapt to changes in environments, such as new development of vasculature and remodeling after vascular injury or during vascular diseases like arteriosclerosis (Owens, 1995). These arterial cells undergo rapid changes in shape and functional property from non-proliferative and contractile to proliferative and mobile phenotype.. Agonist stimulation of VSMCs induces phosphorylation of the 20 kDa regulatory light chain of myosin (MLC), which increases actin-activated myosin ATPase activity and contraction (Hartshorne, 1987; Somlyo and Somlyo, 2003). MLC phosphorylation is governed by the opposing ...

TY - JOUR. T1 - Myosin II is involved in the production of constitutive transport vesicles from the TGN. AU - Müsch, Anne. AU - Cohen, David. AU - Rodriguez-Boulan, Enrique. PY - 1997/7/28. Y1 - 1997/7/28. N2 - The participation of nonmuscle myosins in the transport of organelles and vesicular carriers along actin filaments has been documented. In contrast, there is no evidence for the involvement of myosins in the production of vesicles involved in membrane traffic. Here we show that the putative TGN coat protein p200 (Narula, N., I. McMorrow, G. Plopper, J. Doherty, K.S. Matlin, B. Burke, and J.L. Stow. 1992. J. Cell Biol. 114: 1113- 1124) is myosin II. The recruitment of myosin II to Golgi membranes is dependent on actin and is regulated by G proteins. Using an assay that studies the release of transport vesicles from the TGN in vitro we provide functional evidence that p200/myosin is involved in the assembly of basolateral transport vesicles carrying vesicular stomatitis virus G protein ...

Sheep polyclonal fast skeletal Myosin antibody validated for WB, IP, ELISA, IHC, Neut, ICC/IF and tested in Human, Mouse, Rat and Rabbit. Immunogen…

Toxoplasma gondii is an obligate intracellular parasite that enters cells by a process of active penetration. Host cell penetration and parasite motility are driven by a myosin motor complex consisting of four known proteins: TgMyoA, an unconventional Class XIV myosin; TgMLC1, a myosin light chain; and two membrane-associated proteins, TgGAP45 and TgGAP50. Little is known about how the activity of the myosin motor complex is regulated. Here, we show that treatment of parasites with a recently identified small-molecule inhibitor of invasion and motility results in a rapid and irreversible change in the electrophoretic mobility of TgMLC1. While the precise nature of the TgMLC1 modification has not yet been established, it was mapped to the peptide Val46-Arg59. To determine if the TgMLC1 modification is responsible for the motility defect observed in parasites after compound treatment, the activity of myosin motor complexes from control and compound-treated parasites was compared in an in vitro ...

Band 2 was identified as myosin heavy chain A (non-muscle) (Fig. 4B). Myosin heavy chain-A, non-muscle, is a cellular/cytoplasmic myosin very similar in structure to the skeletal, cardiac, and smooth muscle myosins. It has been identified in a wide range of cells including yeast and mammalian cells (22). The key feature of cytoplasmic myosin is its binding to actin filaments thereby generating contractile forces during cytokinesis and in maintaining cortical tension because of the hydrolysis of ATP. The function of cytoplasmic myosin is known to be regulated by its phosphorylation state (23). In Dictyostelium, for example, specific phosphorylation of threonine residues 1823, 1833, and 2029 is observed, which drives myosin from filamentous to a monomeric state thereby inhibiting cellular activity (24).. Tandem mass spectrometry was performed to confirm the identity of the protein migrating at 120 kDa in band 3. It was revealed to be drebrin 1 (F-actin-binding protein) (data not shown). It is an ...

© 2015 Elsevier Inc. Abstract We have investigated the effect of the E41K, R91G, and E139del β-tropomyosin (TM) mutations that cause congenital myopathy on the position of TM and orientation of actin monomers and myosin heads at different mimicked stages of the ATPase cycle in troponin-free ghost muscle fibers by polarized fluorimetry. A multi-step shifting of wild-type TM to the filament center accompanied by an increase in the amount of switched on actin monomers and the strongly bound myosin heads was observed during the ATPase cycle. The R91G mutation shifts TM further towards the inner and outer domains of actin at the strong- and weak-binding stages, respectively. The E139del mutation retains TM near the inner domains, while the E41K mutation captures it near the outer domains. The E41K and R91G mutations can induce the strong binding of myosin heads to actin, when TM is located near the outer domains. The E139del mutation inhibits the amount of strongly bound myosin heads throughout the ATPase

Cytokinesis is the process by which a cell partitions its surface and cytoplasm to form two daughter cells. In both animal and yeast cells, this process involves the assembly and contraction of an actomyosin ring. It is noteworthy that for a long time, among the hundreds of myosins known, only the conventional myosins of class II had been implicated in cell division (Field et al., 1999). However, a recent study established the involvement of two myosins of type V in S. pombe (Win et al., 2001). The asexual multiplication of T. gondii occurs by a peculiar process named endodyogeny, which is defined as the gradual development of two daughter parasites within a fully differentiated mother; the mother is incorporated into the daughters during the process (Fig. 1). In T. gondii, actin inhibitors did not prevent replication, per se, but disrupted the inheritance of mother cell organelles, resulting in the formation of residual bodies (Shaw et al., 2000). Therefore, myosin motor(s) were anticipated to ...

anti-Myosin Regulatory Light Chain 2, Smooth Muscle Isoform (MYL9) (pThr19), (AA 10-25) antibody (Cy5.5) ABIN753243 from antibodies-online

BACKGROUND: In contrast to conventional muscle myosins, where two different light chains (LCs) stabilize the elongated regulatory domain (RD) region of the head portion of the molecule, unconventional myosins are a diverse group of motors in which from one to six calmodulin (CaM) subunits are bound tandemly to the RD. In both cases, the heavy chains of the RDs have special sequences called IQ motifs to which the LCs or CaM bind. A previously puzzling aspect of certain unconventional myosins is their unusual mode of regulation, where activation of motility occurs at low levels of Ca2+. Although the atomic structure of the conventional muscle myosin RD has been determined, no crystallographic structure of the RD of an unconventional myosin is yet available. RESULTS: We have constructed a model of vertebrate CaM bound to the first IQ motif present in the neck region of an unconventional myosin (chicken brush border myosin I), using strict binding rules derived from the crystal structure of the ...

A monomeric myosin first spotted in electron micrographs almost 30 years ago has finally been united with a proposed function. Tyska and Mooseker (page 395) report that myosin-1A associates with and anchors a raft component in apical membranes.. Myosin-1A was previously thought to shuttle Golgi-derived cargos to the plasma membrane (after most of the distance had been covered using microtubule-based motors). But the in vitro evidence for this came from undifferentiated cells, and in mature, polarized colon epithelial cells, Tyska and Mooseker see no evidence of shuttling by myosin-1A. What they did spot was cofractionation and cross-linking of myosin-1A with the transmembrane disaccharidase sucrase-isomaltase (SI). This raft protein is lost from the apical surface when a fragment of either myosin-1A or SI interferes with the link between the two full-length proteins.. Thus, myosin-1A may serve as an anchor, with the clustering of SI in rafts helping to secure the link even if an individual ...

We studied the effect of chronic mechanical overloading on the isoenzyme composition of rat cardiac myosin in several experimental models: aortic stenosis (AS), aortic incompetence (AI), aortocaval fistula (ACF), overload of the non-infarcted area after left coronary ligation (INF), and overload of the spontaneously hypertensive rats (SHR). Samples of the left and right ventricles were isolated from these hearts, and myosins were analyzed by electrophoresis in non-dissociating conditions. The myosin isoenzymes were called V1, V2, and V3 in order of decreasing mobility, according to the nomenclature of Hoh et al. Controls of the Wistar and Wistar Kyoto (WKY) strains were almost exclusively V1, A slow age-dependent shift toward V3 was observed in the left ventricles of adult Wistar rats, which at 30 weeks of age (body weight 600 g) contained approximately 15% of this form. In all models of cardiac hypertrophy, an isoenzymic redistribution was observed with a significant increase in V3. The level ...

Define myosin. myosin synonyms, myosin pronunciation, myosin translation, English dictionary definition of myosin. n. Any of a class of proteins that bind with actin filaments and generate many kinds of cell movement, especially the contraction of myofibrils in muscle...

TY - JOUR. T1 - Primary structure and cellular localization of chicken brain myosin-V (p190), an unconventional myosin with calmodulin light chains. AU - Espreafico, Enilza M.. AU - Cheney, Richard E.. AU - Matteoli, Michela. AU - Nascimento, Alexandra A C. AU - De Camilli, Pietro V.. AU - Larson, Roy E.. AU - Mooseker, Mark S.. PY - 1992/12. Y1 - 1992/12. N2 - Recent biochemical studies of p190, a calmodulin (CM)-binding protein purified from vertebrate brain, have demonstrated that this protein, purified as a complex with bound CM, shares a number of properties with myosins (Espindola, F. S., E. M. Espreafico, M. V. Coelho, A. R. Martins, F. R. C. Costa, M. S. Mooseker, and R. E. Larson. 1992. J. Cell Biol. 118:359-368). To determine whether or not p190 was a member of the myosin family of proteins, a set of overlapping cDNAs encoding the full-length protein sequence of chicken brain pi 90 was isolated and sequenced. Verification that the deduced primary structure was that of p190 was ...

Anti-Myosin VI polyclonal antibody (STJ96437) was developed using a synthesized peptide derived from the N-terminal region of human Myosin VI at AA range: 40-120. This antibody is applicable for use in western blot, immunohistochemistry-P, ELISA and immun

The actin cytoskeleton is crucial for function and morphology of neuronal synapses. Moreover, altered regulation of the neuronal actin cytoskeleton has been implicated in neuropsychiatric diseases such as autism spectrum disorder (ASD). Myosin XVI is a neuronally expressed unconventional myosin known to bind the WAVE regulatory complex (WRC), a regulator of filamentous actin (F-actin) polymerization. Notably, the gene encoding the myosins heavy chain (MYO16) shows genetic association with neuropsychiatric disorders including ASD. Here, we investigated whether myosin XVI plays a role for actin cytoskeleton regulation in the dendritic spines of cerebellar Purkinje cells (PCs), a neuronal cell type crucial for motor learning, social cognition and vocalization. We provide evidence that both myosin XVI and the WRC component WAVE1 localize to PC spines. Fluorescence recovery after photobleaching (FRAP) analysis of GFP-actin in cultured PCs shows that Myo16 knockout as well as PC-specific Myo16 knockdown,

Purification of native myosin filaments from muscle.: Analysis of the structure and function of native thick (myosin-containing) filaments of muscle has been ha

The smaller subunits of MYOSINS that bind near the head groups of MYOSIN HEAVY CHAINS. The myosin light chains have a molecular weight of about 20 KDa and there are usually one essential and one regulatory pair of light chains associated with each heavy chain. Many myosin light chains that bind calcium are considered calmodulin-like proteins ...

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 ...

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

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 ...

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

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. ...

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 ...

As a member of the wwPDB, the RCSB PDB curates and annotates PDB data according to agreed upon standards. The RCSB PDB also provides a variety of tools and resources. Users can perform simple and advanced searches based on annotations relating to sequence, structure and function. These molecules are visualized, downloaded, and analyzed by users who range from students to specialized scientists.

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 ...

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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