Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.6.4.1 (myosin ATPase)
 1,140 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The distribution of collagen fibers of rat masticatory muscles during the postnatal period (two weeks), was investigated by electrophoresis and immunohistochemistry. At these stages, the myosin of rat masticatory muscles displays specific electrophoretic patterns. Comparison of the myosin patterns of these muscles allows their identification. 1) Analysis by SDS-PAGE indicated that one of three weakly reactive stainable proteins with lower mobility than the heavy chain of myosin disappeared from the temporal muscle on day 13, as compared with other masticatory muscles. However, in histochemical analysis of the muscle fibers, the reaction specific for succinic dehydrogenase (SDH) activity was strong, and the fibers on day 13 could be classified into two types with respect to SDH activity. By contrast, on day 0, the fibers were classified into two types with respect to myosin ATPase activity. 2) Immunohistochemical analysis indicated that the distribution of the components of the extracellular matrix in the epimysium (type I collagen), perimysium (type I collagen, fibronectin, and laminin) and endomysium (type III collagen, fibronectin, laminin, and tenascin) was related to the metabolic capacity on days 12 to 13. The variability in the types of myosin and in proteins of the extracellular matrix might be important during the development of rat masticatory muscles.
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PMID:Distribution of the macromolecular components of masticatory muscles during differentiation of the muscle fibers in the postnatal rat. 857 Jan 40

The mechanism by which vascular smooth muscle (VSM) cells modulate their contractility in response to structural cues from extracellular matrix remains poorly understood. When pulmonary VSM cells were cultured on increasing densities of immobilized fibronectin (FN), cell spreading, myosin light chain (MLC) phosphorylation, cytoskeletal prestress (isometric tension in the cell before vasoagonist stimulation), and the active contractile response to the vasoconstrictor endothelin-1 all increased in parallel. In contrast, MLC phosphorylation did not increase when suspended cells were allowed to bind FN-coated microbeads (4.5-microm diameter) or cultured on micrometer-sized (30 x 30 microm) FN islands surrounded by nonadhesive regions that support integrin binding but prevent cell spreading. Cell spreading and MLC phosphorylation also both decreased in parallel when the mechanical compliance of flexible FN substrates was raised. MLC phosphorylation was inhibited independently of cell shape when cytoskeletal prestress was dissipated using a myosin ATPase inhibitor in fully spread cells, whereas it increased to maximal levels when microtubules were disrupted using nocodazole in cells adherent to FN but not in suspended cells. These data demonstrate that changes in cell-extracellular matrix (ECM) interactions modulate smooth muscle cell contractility at the level of biochemical signal transduction and suggest that the mechanism underlying this regulation may involve physical interplay between ECM and the cytoskeleton, such that cell spreading and generation of cytoskeletal tension feed back to promote MLC phosphorylation and further increase tension generation.
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PMID:Extracellular matrix controls myosin light chain phosphorylation and cell contractility through modulation of cell shape and cytoskeletal prestress. 1476 83

Cadherins and integrins are major adhesion molecules regulating cell-cell and cell-matrix interactions. In vitro and in vivo studies have demonstrated the existence of crosstalk between integrins and cadherins in cell adhesion and motility. We used a dual pipette assay to measure the force required to separate E-cadherin-producing cell doublets and to investigate the role of integrin in regulating the strength of intercellular adhesion. A greater force was required to separate cell doublets bound to fibronectin or vitronectin-coated beads than for doublets bound to polylysine-coated beads. This effect depended on cell spreading and the duration of stimulation. Cells expressing type II cadherin-7 also responded to fibronectin stimulation to produce a higher intercellular adhesion. Establishment of cadherin-mediated adhesion needed ROCK, MLCK and myosin ATPase II activity. The regulation of intercellular adhesion strength by integrin stimulation required activation of Src family kinases, ROCK and actomyosin contractility. These findings highlight the importance and mechanisms of molecular crosstalk between cadherins and integrins in the control of cell plasticity during histogenesis and morphogenesis.
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PMID:Integrins stimulate E-cadherin-mediated intercellular adhesion by regulating Src-kinase activation and actomyosin contractility. 2014 95