What is myotonin protein kinase?
100814
myotonin protein kinase: gene product of myotonic dystrophy is localized in the sarcoplasmic reticulum of skeletal muscle. Also, may be located at the intercalated discs and have a different isoform in cardiac tissue.\n\nIt is quite important to know the exact localization and function of myotonin protein kinase (MtPK), identified as the gene product of myotonic dystrophy, the most prevalent disease with multisystem disorders among muscular dystrophies. To investigate the localization of MtPK, we raised a polyclonal antibody against a synthetic peptide chosen within the deduced sequence of MtPK. This antibody detected both a membrane-bound 70-kd protein and a soluble 55-kd protein on Western blots of human muscles. By using this antibody for immunohistochemical studies of both biopsied human skeletal muscle fibers and mature innervated cultured muscle fibers, we can now demonstrate by confocal laser scanning microscopy that MtPK is localized mainly in the I-band. By immunoelectron microscopy, it was determined that MtPK is a membrane-bound protein localized mainly in the terminal cisternae of the sarcoplasmic reticulum. To our knowledge, this is the first documentation of the ultrastructural localization of MtPK. This finding is quite important for clarifying the pathophysiological basis of myotonic dystrophy, which might be due to a dysregulation of calcium metabolism.
81671
Muscle disruption means muscle rupture.\n\nMuscle damage means myocells are not performing the action or dead.
85291
In the absence of calcium ions, tropomyosin blocks access to the mysosin binding site of actin. When calcium binds to troponin, the positions of troponin and tropomyosin are altered on the the thin flament and myosin then has access to its binding site on actin.\n\nMyosin hydolyzes ATP and undergoes a conformational change into a high-energy state. The head group of myosin binds to actin forming a cross-bridge between the thick and thin filaments. The energy stored by myosin is released, and ADP and inorganic phosphate dissociate from myosin. The resulting relaxation of the myosin molecule entails rotation of the globular head, which induces longitudinal sliding of the filaments.\n\nWhen the calcium level decreases, troponin locks tropomyosin in the blocking position and the thin filament slides back to the resting state.
650844
Jock Itch. Get tough actin Tinactin.
547015
Muscle cells undergo hypertrophy when they are exercised (resistance training).  Hypertrophy means each fibre that makes up the muscle increases in width but not in number.  The current theory is that small tears are produced in the muscle when it is worked out.  As these tears are healed during recovery (~48hrs after exercise) the muscle lays down new contractile filaments (protein) and begins to increase in diameter.  Some research does suggest that hyperplasia (increased muscle cells) can occur when the muscle reaches a very large size, but this has not been completely proven yet.  Satellite cells, which are stem-like cells in the muscle can also be stimulated by hormones produced by exercise (like IGF-2) to migrate into the muslce and join with existing muscle cells.  This adds nuclei to the existing cells along with contractile filaments allowing the muscle to increase in diameter (hypertrophy).
971960
Yeah, more mitochondria for energy and more ribosomes (rough ER) to produce proteins necessary for contraction (actin + myosin).\n\nRegards,\nRyan
801326
Signal molecules are often called ligands, and they bind to receptors on the outside of cells.  The proteins (or glycoproteins) that we call receptors are membrane bound proteins (like a G-protein coupled receptor.  So, ligands (like a hormone) bind reversibly to these receptors, and begin the G-Protein signaling cascade.  After stimulating the receptor, they are simply knocked off or fall off.\n\nWhen a ligand stimulates a G-Protein coupled receptor, the receptor changes conformation, allowing it to associate with a 3-unit (trimeric) G-Protein.  The alpha unit of the G-protein interacts with the receptor, and changes, where a bound GDP is replaced by a GTP molecule.  The G-protein/GTP complex then activates a protein called adenylyl cyclase, which converts free cytoplasmic ATP into cAMP (cyclic AMP).  The cAMP then activates PROTEIN KINASES, which in turn activate transcription factors, initiating transcription of some final gene product.\n\nLet me give you an example.  Fight or flight response, the body needs extra glucose to give to muscle cells, the heart, the brain, etc . . . the sympathetic system is activated, and the adrenal gland releases epinephrine.  Epi then circulates where in liver cells, it binds to a G-Protein coupled receptor called a Beta-adrenergic receptor (adrenergic always refers to a receptor that epinephrine binds to).  The receptor interacts with a G-Protein, the G-protein complexes with GTP, the GTP/G-protein complex activate adenylyl cyclase, ATP is converted to cAMP, transcription factors are activated, proteins that lead to glucose production are transcribed and translated.  As a result, more glucose is released into the bloodstream for skeletal muscle to use as energy.\n\nThis is just one example of how a G-Protein works, there are others, but this gives you a basic idea of cell signaling.  Cell signaling is EVERYWHERE, it is very important to understand it.
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When a muscle is stimulated more than once in a brief period, the contractions produced by those stimuli can be summed. Each muscular contraction is an all-or-nothing process (including contraction and relaxation of the muscle fiber), and the action potentials (AP) in the cell are not added to other AP. \nBut if the nervous stimuli are closer together, the contractions will undergo summation because the motor units don't have time to relax.\nIf new stimuli occur at high frequency, and the motor units cannot relax at all, tetany ensues = an homogeneous fusion of contractions.
56795
"silent information regulator" proteins.
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Dopamine, Serotonin 2A and GABA A
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http://en.wikipedia.org/wiki/Oxidative_phosphorylation\n \nthis site should be useful for that
680721
low serotonin equals depression
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CPK  is creatine phosphokinase, an enzyme found in heart, muscle, and brain tissue. An elevation in CPK  most often alerts physicians to order an MB fraction, the one specific for cardiac (heart). Usually if the MB fraction is normal you can rule out cardiac damage. Therefore, it is very likely that  your son had  high CPK levels due to the weight lifting because of severe muscle strain
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Specifically, CPK is creatinine kinase, and it is one of two cardiac enzymes a doctor will check if he/she suspects a heart attack.  However, the CPK level can be elevated for other reasons, such as mucle tissue damage in other parts of the body.
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The contraction phenomenon in muscular cells are mostly due to interaction of two elements, ie, Actin and Myosin. Their interaction are powered by some molecules called ATP. The ATP is produced in some cellular structures called mitochondria. The role of food for human is to produce energy. Energy is produced by hydrolyzing of ATP.
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threonine\n\nthere should be a table in your textbook with mRNA codons and corresponding AA's.
767674
a muscle fiber found near the heart.\n\nA cylindrical multinucleated cell composed of myofibrils that contract when stimulated.