What are the steps in the formation of transverse arcs? In general, initiation of stress fiber formation is modulated by signaling cascades involving RhoA small GTPase [1] (reviewed in [2]). Most G-actin polymerization is driven by the actin polymerizing machinery at the barbed end [...]
What are the steps in ventral stress fiber formation? Recent data suggests that ventral stress fibers are created by reorganizing pre-existing dorsal stress fibers and transverse arcs [1].Other contrasting models for the formation of ventral stress fibers not covered in this resource include annealing [...]
How is stress fiber assembly regulated? Tension-dependent actin polymerization and assembly of stress fibers is influenced by many factors (reviewed in [1][2]), including differences in substrate composition [3], rigidity [4][5][6] (reviewed in [7]), cell membrane phospholipids [8], external force (reviewed in [9]), as well [...]
How do lipid bilayer components move? One of the tenets of the Fluid-Mosaic membrane model is that the components of the bilayers are free to move. Before describing the differences between lipid and protein movement in the bilayer, it is important to consider the [...]
Why are membrane lipids asymmetrical? The human red blood cell is functionally specialized for transporting oxygen. In order to maximize oxygen capacity, it has no nucleus or organelles, consisting primarily of plasma membrane and hemoglobin. This made it an ideal candidate for membrane studies. [...]
What are cell membranes? What are the physiological functions of biological membranes? Eukaryotic cells and their organelles are enveloped by viscoelastic layers made of lipids and proteins. These layers are generally referred to as cell membranes and when they surround the entire cell, they [...]
What steps are involved in the myosin powerstroke? Each myosin motor protein possesses ATPase activity and functions in a cyclical manner that couples ATP binding and hydrolysis to a conformational change in the protein. This process is known as the ‘powerstroke cycle’ (reviewed in [...]
What is Myosin Light Chain Kinase? Myosin light chain kinase (MLCK) is a calcium/calmodulin-dependent serine/threonine kinase, belonging to the immunoglobulin superfamily. It phosphorylates the regulatory myosin light chains of myosin II, in order to facilitate myosin binding to actin and therefore aid contractility. Its [...]
What are cytoskeletal cages? Cytoskeletal components can assemble into cage-like structures within the cell. These cages serve to segregate intracellular regions or organelles, and can protect their contents from mechanical stress. At the level of the whole cell, the cell cortex is a meshwork [...]
Cytoskeleton Dynamics The cytoskeleton is a highly dynamic network of filamentous proteins that exists in the 3D space to link all regions and components of the cell. All cells, including bacteria, have a cytoskeleton in one form or another. This network is multifunctional, providing [...]
What is the plasma membrane? Plasma membranes are subcellular structures, approximately 10nm thick, that form a protective boundary around the cell as well as the cell’s organelles. They serve to both impede foreign material from entering the cell, and prevent the cellular contents from [...]
How do mechanically-gated ion channels facilitate mechanotransduction? Mechanotransduction relies on the ability of cells to convert mechanical cues, such as stretch or compression, to biochemical signals. One way this occurs is through the activity of mechanically-gated ion channels. Calcium ions channels: Physiologically, calcium ions [...]
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One of four Research Centres of Excellence at NUS, MBI is working to identify, measure and describe how the forces for motility and morphogenesis are expressed at the molecular, cellular and tissue level.