What are Motor Proteins? Motor proteins, such as myosins and kinesins, move along cytoskeletal filaments via a force-dependent mechanism that is driven by the hydrolysis of ATP molecules (reviewed in [1]). Nucleotide hydrolysis and controlled inorganic phosphate release by motor proteins causes restructuring of [...]
How do motor proteins transport cargo along the cytoskeleton? Along with providing structural support to the cell, and transmitting force signals, cytoskeletal filaments also provide cells with a network of ‘tracks’ that can be followed by specific proteins for the directed delivery of vesicles [...]
What is Myosin? An Introduction to the Myosin Superfamily of Proteins Myosin I has unique tail domain(s) relative to other myosin members which allows myosin I to bind to membrane lipids or to more than one actin filament at a time (see panel ‘A’ [...]
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 [...]
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 [...]
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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.