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)

Human myosin light chain-2 (MYL2) is an important protein involved in the regulation of myosin ATPase activity in smooth muscle. In cardiac muscle, the precise role of MYL2 is not well understood; however, an increase in ventricular MYL2 is observed during myocardial hypertrophy in cardiac patients with valve stenosis. The chromosomal location of the gene coding for MYL2 was identified using a cloned cDNA for human MYL2. Southern blot analysis of DNA from a human/rodent somatic cell hybrid mapping panel showed that the BamHI fragment that hybridized with this cDNA probe was concordant with chromosome 12. The 768-bp cDNA was hybridized to human metaphase chromosomes. The results revealed a significant clustering of silver grains over chromosome 12 bands q23-q24.3, indicating that the gene coding for MYL2 is located in this region.
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PMID:Localization of the gene coding for ventricular myosin regulatory light chain (MYL2) to human chromosome 12q23-q24.3. 138 40

Cross-reinnervation studies performed ex ovo with newly hatched chicks demonstrate that peripheral motor neurons control the phenotypic characteristics of avian muscles. The present experiments were designed to determine whether or not nerves play a similar role during the initial expression of muscle fiber types. Previous experiments indicated that differentiation of specific fiber types occurs during the first week of embryogenesis, temporally coincident with the penetration of nerves within muscle masses. These observations suggested that peripheral nerves may be associated with the initial differentiation of fiber types. To test this hypothesis directly, anterior limb buds of the chick embryo were rendered aneurogenic by deletion of the brachial segment of the neural tube. To ensure a completely aneurogenic environment for developing brachial muscles, surgery was performed at day 2 in ovo before the exit of ventral root fibers. Experimental and control embryos from Stage (St) 25 (4.5 d) through St 45 (19d) were analyzed histochemically by a silver-cholinesterase reaction to detect nerves and by the myosin ATPase reaction, following alkali and acid preincubation, to determine the fiber type composition of the muscles. In addition, the total volume of aneurogenic and control muscles was compared. Results demonstrate that the characteristic myosin ATPase profiles of individual aneurogenic and innervated (control) muscles were identical throughout the entire period analyzed. Therefore, we conclude that these enzymic profiles are endogenously expressed and are not under neuronal control during early embryogenesis. Furthermore, the entire sequence of events from the migration of myogenic cells to the anterior limb bud through the division of the primary muscle masses to form individual brachial muscles proceeded on schedule in the absence of nerves. Since the growth of aneurogenic muscles was impaired, we conclude that during embryogenesis peripheral motor nerves are necessary initially for the proper growth of muscles and ultimately, for their survival. They are not involved, however, with either the initial formation or initial differentiation of individual brachial muscles.
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PMID:Differentiation of muscle fiber types in aneurogenic brachial muscles of the chick embryo. 621 81