Actin

of cytoskeletal element (microtubules and actin): Lamellipodia is the base of the cone which is comprised of actin mesh work stabilized by microtubule whereas Filopodia is the finger-like projection entirely comprised of actin. The movement of growth cone is regulated by polymerization/depolymerization of actin and tubulin. Polymerization is defined as the addition of strands in G-actin (monomeric Globular actin) to form F-actin (polymeric Fibrous actin). Various Rho family GTPases like RAC1 and…

binding of contractile units. Actin filaments project from one end of the dense bodies. Suspended in between the actin are the thick myosin filaments. When the smooth muscle is stimulated to contract, the myosin filaments will start inching toward the actin, resulting in the shortening of fibers. Essentially, once the mesh-like structure of the smooth muscle cell is activated, it will pull the cell membrane inward. The highest force output is generated when the actin and myosin overlap…

cell. eEF1A has been identified as an actin binding protein. Competitive binding experiments with eEF1A, F-actin and aa-tRNA showed that as pH increases, the affinity of eEF1A for F-actin decreased while that for aa-tRNA increased (2). A previous work done by the Kinzy lab two classes of eEF1A mutants were generated. Class one mutants, N305S- and N329S-Ura3p, were found to maintain normal levels of global translation while exhibiting disorganization of actin cytoskeleton. Class two mutants,…

There are many different parts of skeletal muscles that are important to the function of the muscles. Each muscle is made up of a lot of muscle fibers. Each muscle fiber has a thin coating covering the fiber called the sarcolemma. The muscle fibers also have a cytoplasmic type substance called sarcoplasm. Sarcoplasm contains large amount of glycosomes and myoglobin. Myoglobin is a protein that stores oxygen inside the muscle fibers. The muscle fibers contain striations that are made up of…

As we have mention on preceding page, actin and myosin filaments inside the sarcomeres of muscle fibres bind to make cross-bridges and glide history one one additional, create a reduction. The sliding filament theory explain how these cross-bridges are bent and the succeeding reduction of power…

Muscles in a way are the most important parts of the body. If we didn’t have muscles it would be impossible to move around, and do things. Muscles make everything we do possible, but there is more to muscles than meets the eye. Yes there are the kinds of muscles which allow us to walk and pick up things, but there are also different kinds of muscles which if anything are equally important. Before we dive into the kinds of muscles and their functions, let’s get a better idea of how muscles work.…

ActA has been shown to have a role in actin rearrangements. Eukaryotic mitochondrial cells transfected with actA display colocalization of ActA with actin indicating ActA has the ability to induce host actin rearrangement (14). Further supporting evidence for the role of actA in L.monocytogenes host intracellular growth is the fact deletion of actA leads to smaller plaque formation on mouse L2 cells (15). Production of ActA and rearranging host actin at a pole allows for L.monocytogenes to be…

present on the actin-containing thin filaments of myofibrils. Troponin proteins consists of three different subunits, Troponin T, Troponin I, and Troponin C, with each subunit being responsible for a different part of troponin function. Troponin T is a tropomyosin-binding subunit and hence regulates the interaction of the troponin complex with actin thin filaments, troponin I is an inhibitor of the ATP-ase activity of myosin and responsible for the inability of myosin binding to actin in the…

Tessa Jones Professor Pericone M.S. Human Anatomy & Physiology I – BIOL 130-03 20 November 2017 The Stiff Truth About Rigor Mortis Growing up, I have always been intrigued by murder mysteries. My favorite shows consisted of Criminal Minds, CSI, and NCIS. From watching these shows episode after episode, I have become familiarized with the term “Rigor Mortis”. Rigor Mortis is referred to as the third stage of death, where the muscles in the body contract leaving the body “stiff” for a period of…

Alexandra Banales X explains Y The purpose of this experiment was to measure the tension, or force, produced by interacting filaments in a muscle fiber. In order to test this, a subject had three electrode disks located on their forearm. These disks were connected to a computer monitor which traced the EMG records and the Force trace of their muscle contraction. Data was observed while the subject changed their hand movement in different ways including wrist positions such as fully flexed,…