Myosin isoforms and their light chains from the ventricular muscle of the urodelan amphibian Pleurodeles waltlii: Comparison with myosin from skeletal muscles

1996 ◽  
Vol 114 (3) ◽  
pp. 257-260 ◽  
Author(s):  
Thierry Launay ◽  
Claude L Gallien ◽  
Christophe Chanoine
Keyword(s):  
Skeletal Muscles ◽  
Light Chains ◽  
Myosin Isoforms ◽  
Ventricular Muscle ◽  
Pleurodeles Waltlii

Subunit composition of rodent isomyosins and their distribution in hindlimb skeletal muscles

1987 ◽  
Vol 63 (5) ◽  
pp. 2101-2110 ◽  
Author(s):  
R. W. Tsika ◽  
R. E. Herrick ◽  
K. M. Baldwin
Keyword(s):  
Light Chain ◽  
Skeletal Muscles ◽  
Slow Light ◽  
Muscular Activity ◽  
Light Chains ◽  
Fiber Types ◽  
Myosin Isoforms ◽  
Adult Skeletal Muscle ◽  
Physiological Importance ◽  
Fast Twitch

Three adult skeletal muscle sarcomeric myosin heavy chain (MHC) genes have been identified in the rat, suggesting that the expressed native myosin isoforms can be differentiated, in part, on the basis of their MHC composition. This study was undertaken to ascertain whether the five major native isomyosins [3 fast (Fm1, Fm2, Fm3), 1 slow (Sm), and 1 intermediate (Im)], typically expressed in the spectrum of adult rat skeletal muscles comprising the hindlimb, could be further differentiated on the basis of their MHC profiles in addition to their light chain composition. Results show that in muscles comprised exclusively of fast-twitch glycolytic (FG) fibers and consisting of Fm1, Fm2, and Fm3, such as the tensor fasciae latae, only one MHC, designated as fast type IIb, could be resolved. In soleus muscle, comprised of both slow-twitch oxidative and fast-twitch oxidative-glycolytic fibers and expressing Sm and Im, two MHC bands were resolved and designated as slow/cardiac beta-MHC and fast type IIa MHC. In muscles expressing a mixture of all three fiber types and a full complement of isomyosins, as seen in the plantaris, the MHC could be resolved into three bands. Light chain profiles were characterized for each muscle type, as well as for the purified isomyosins. These data suggest that Im (IIa) consists of a mixture of fast and slow light chains, whereas Fm (IIb) and Sm (beta) isoforms consist solely of fast- and slow-type light chains, respectively. Polypeptide mapping of denatured myosin extracted from muscles expressing contrasting isoform phenotypes suggests differences in the MHC primary structure between slow, intermediate, and fast myosin isotypes. These findings demonstrate that 1) Fm, Im, and Sm isoforms are differentiated on the bases of both their heavy and light chain components and 2) each isomyosin is distributed in a characteristic fashion among rat hindlimb skeletal muscles. Furthermore, these data suggest that the ratio of isomyosins in a given muscle or muscle region is of physiological importance to the function of that muscle during muscular activity.

Diabetes decreases Na+-K+ pump concentration in skeletal muscles, heart ventricular muscle, and peripheral nerves of rat

Diabetes ◽  
1987 ◽  
Vol 36 (7) ◽  
pp. 842-848 ◽  
Author(s):  
K. Kjeldsen ◽  
H. Braendgaard ◽  
P. Sidenius ◽  
J. S. Larsen ◽  
A. Norgaard
Keyword(s):  
Peripheral Nerves ◽  
Skeletal Muscles ◽  
Ventricular Muscle

scholarly journals Myosins and pathology: genetics and biology.

2002 ◽  
Vol 49 (4) ◽  
pp. 789-804 ◽  
Author(s):  
Maria Jolanta Redowicz
Keyword(s):  
Hypertrophic Cardiomyopathy ◽  
Myosin Heavy Chain ◽  
Inner Ear ◽  
Heavy Chain ◽  
Hair Cells ◽  
Familial Hypertrophic Cardiomyopathy ◽  
Light Chains ◽  
Myosin Isoforms ◽  
Cardiac Myosin ◽  
Genes Encoding

This article summarizes current knowledge on the genetics and possible molecular mechanisms of Human pathologies resulted from mutations within the genes encoding several myosin isoforms. Mutations within the genes encoding some myosin isoforms have been found to be responsible for blindness (myosins III and VIIA), deafness (myosins I, IIA, IIIA, VI, VIIA and XV) and familial hypertrophic cardiomyopathy (beta cardiac myosin heavy chain and both the regulatory and essential light chains). Myosin III localizes predominantly to photoreceptor cells and is proved to be engaged in the vision process in Drosophila. In the inner ear, myosin I is postulated to play a role as an adaptive motor in the tip links of stereocilia of hair cells, myosin IIA seems to be responsible for stabilizing the contacts between adjacent inner ear hair cells, myosin VI plays a role as an intracellular motor transporting membrane structures within the hair cells while myosin VIIA most probably participates in forming links between neighbouring stereocilia and myosin XV probably stabilizes the stereocilia structure. About 30% of patients with familial hypertrophic cardiomyopathy have mutations within the genes encoding the beta cardiac myosin heavy chain and both light chains that are grouped within the regions of myosin head crucial for its functions. The alterations lead to the destabilization of sarcomeres and to a decrease of the myosin ATPase activity and its ability to move actin filaments.

Myosin light chains in normal and pathological human skeletal muscles

1983 ◽  
Vol 6 (1) ◽  
pp. 40-47 ◽  
Author(s):  
Fran�oise Pons ◽  
Jocelyne Leger ◽  
Michel Georgesco ◽  
Fran�ois Bonnel ◽  
Jean J. Leger
Keyword(s):  
Skeletal Muscles ◽  
Light Chains ◽  
Myosin Light Chains ◽  
Human Skeletal Muscles

Response of slow and fast muscle to hypothyroidism: maximal shortening velocity and myosin isoforms

1992 ◽  
Vol 263 (1) ◽  
pp. C86-C94 ◽  
Author(s):  
V. J. Caiozzo ◽  
R. E. Herrick ◽  
K. M. Baldwin
Keyword(s):  
Skeletal Muscles ◽  
Relative Content ◽  
Type I ◽  
Myosin Isoforms ◽  
Velocity Data ◽  
Sprague Dawley ◽  
Shortening Velocity ◽  
Sprague Dawley Rats ◽  
Force Velocity ◽  
Fast Twitch

This study examined both the shortening velocity and myosin isoform distribution of slow- (soleus) and fast-twitch (plantaris) skeletal muscles under hypothyroid conditions. Adult female Sprague-Dawley rats were randomly assigned to one of two groups: control (n = 7) or hypothyroid (n = 7). In both muscles, the relative contents of native slow myosin (SM) and type I myosin heavy chain (MHC) increased in response to the hypothyroid treatment. The effects were such that the hypothyroid soleus muscle expressed only the native SM and type I MHC isoforms while repressing native intermediate myosin and type IIA MHC. In the plantaris, the relative content of native SM and type I MHC isoforms increased from 5 to 13% and from 4 to 10% of the total myosin pool, respectively. Maximal shortening velocity of the soleus and plantaris as measured by the slack test decreased by 32 and 19%, respectively, in response to hypothyroidism. In contrast, maximal shortening velocity as estimated by force-velocity data decreased only in the soleus (-19%). No significant change was observed for the plantaris.

Diabetes Decreases Na+-K+ Pump Concentration in Skeletal Muscles, Heart Ventricular Muscle, and Peripheral Nerves of Rat

Diabetes ◽  
1987 ◽  
Vol 36 (7) ◽  
pp. 842-848 ◽  
Author(s):  
K. Kjeldsen ◽  
H. Braendgaard ◽  
P. Sidenius ◽  
J. S. Larsen ◽  
A. Norgaard
Keyword(s):  
Peripheral Nerves ◽  
Skeletal Muscles ◽  
Ventricular Muscle

scholarly journals Developmental regulation of myosin gene expression in mouse cardiac muscle.

1990 ◽  
Vol 111 (6) ◽  
pp. 2427-2436 ◽  
Author(s):  
G E Lyons ◽  
S Schiaffino ◽  
D Sassoon ◽  
P Barton ◽  
M Buckingham
Keyword(s):  
Gene Expression ◽  
Cardiac Muscle ◽  
Ventricular Myocytes ◽  
Muscle Cells ◽  
Mouse Heart ◽  
Myosin Isoforms ◽  
Mrna Levels ◽  
Ventricular Muscle ◽  
Ventricular Cells ◽  
Low Levels

Expression of the two isoforms of cardiac myosin heavy chain (MHC), MHC alpha and MHC beta, in mammals is regulated postnatally by a variety of stimuli, including serum hormone levels. Less is known about the factors that regulate myosin gene expression in rapidly growing cardiac muscle in embryos. Using isoform-specific 35S-labeled cRNA probes corresponding to the two MHC genes and the two myosin alkali light chain (MLC) genes expressed in cardiac muscle, we have investigated the temporal and spatial pattern of expression of these different genes in the developing mouse heart by in situ hybridization. Between 7.5 and 8 d post coitum (p.c.), the newly formed cardiac tube begins to express MHC alpha, MHC beta, MLC1 atrial (MLC1A), and MLC1 ventricular (MLC1V) gene transcripts at high levels throughout the myocardium. As a distinct ventricular chamber forms between 8 and 9 d p.c., MHC beta mRNAs begin to be restricted to ventricular myocytes. This process is complete by 10.5 d p.c. During this time, MHC alpha mRNA levels decrease in ventricular muscle cells but continue to be expressed at high levels in atrial muscle cells. MHC alpha transcripts continue to decrease in ventricular myocytes until 16 d p.c., when they are detectable at low levels, but then increase, and finally replace MHC beta mRNAs in ventricular muscle by 7 d after birth. Like MHC beta, MLC1V transcripts become restricted to ventricular myocytes, but at a slower rate. MLC1V mRNAs continue to be detected at low levels in atrial cells until 15.5 d p.c. MLC1A mRNA levels gradually decrease but are still detectable in ventricular cells until a few days after birth. This dynamic pattern of changes in the myosin phenotype in the prenatal mouse heart suggests that there are different regulatory mechanisms for cell-specific expression of myosin isoforms during cardiac development.

0897 Label-free quantification of myosin isoforms in porcine skeletal muscles

2016 ◽  
Vol 94 (suppl_5) ◽  
pp. 432-432
Author(s):  
J. Y. Jeong ◽  
H. S. Yang ◽  
J. K. Seo ◽  
H. W. Yum ◽  
G. D. Kim
Keyword(s):  
Skeletal Muscles ◽  
Myosin Isoforms ◽  
Label Free ◽  
Label Free Quantification ◽  
Free Quantification

Muscle sarcomere lesions and thrombosis after spaceflight and suspension unloading

1992 ◽  
Vol 73 (2) ◽  
pp. S33-S43 ◽  
Author(s):  
D. A. Riley ◽  
S. Ellis ◽  
C. S. Giometti ◽  
J. F. Hoh ◽  
E. I. Ilyina-Kakueva ◽  
...  
Keyword(s):  
Weight Bearing ◽  
Eccentric Contraction ◽  
Light Chains ◽  
Myosin Light Chains ◽  
Myosin Isoforms ◽  
Myofibrillar Proteins ◽  
Fatty Acid Binding ◽  
Fast Myosin ◽  
Slow Twitch ◽  
Fast Twitch

Spaceflight (flight) and tail suspension-hindlimb unloading (unloaded) produced significant decreases in fiber cross-sectional areas of the adductor longus (AL), a slow-twitch antigravity muscle. However, the mean wet weight of the flight AL muscles was near normal, whereas that of the suspension unloaded AL muscles was significantly reduced. Interstitial edema within the flight AL, but not in the unloaded AL, appeared to account for this apparent disagreement. In both experimental conditions, the slow-twitch oxidative fibers atrophied more than the fast-twitch oxidative-glycolytic and fast-twitch glycolytic fibers. Immunostaining showed that slow-twitch oxidative fibers expressed fast myosin, producing hybrid fibers containing slow and fast myosin isoforms. Two-dimensional gel electrophoresis of flight AL muscles revealed increased content of fast myosin light chains and decreased amounts of slow myosin light chains and fatty acid-binding protein. In the flight AL, absolute mitochondrial content decreased, but the relatively greater breakdown of myofibrillar proteins maintained mitochondrial concentration near normal in the central intermyofibrillar regions of fibers. Subsarcolemmal mitochondria were preferentially lost and reduced below normal concentration. Elevated fiber immunostaining for ubiquitin conjugates was suggestive of ubiquitin-mediated breakdown of myofibrillar proteins. On return to weight bearing for 8–11 h, the weakened atrophic muscles exhibited eccentric contraction-like lesions (hyperextension of sarcomeres with A-band filaments pulled apart and fragmented), tearing of the supporting connective tissue, and thrombosis of the microcirculation. Segmental necrosis of muscle fibers, denervation of neuromuscular junctions, and extravasation of red blood cells were minimal. Lymphocyte antibody markers did not indicate a significant immune reaction. The flight AL exhibited threefold more eccentric-like lesions than the unloaded AL; the high reentry G forces experienced by the flight animals, but not the unloaded group, possibly accounted for this difference. Muscle atrophy appears to increase the susceptibility to form eccentric contraction-like lesions after reloading; this may reflect weakening of the myofibrils and extracellular matrix. Microcirculation was also compromised by spaceflight, such that there was increased formation of thrombi in the post-capillary venules and capillaries. This blockage led to edema by 8–11 h after resumption of weight bearing by the COSMOS 2044 rats. The present findings indicate that defective microcirculation most likely accounted for the extensive tissue necrosis and microhemorrhages observed for COSMOS 1887 rats killed 2 days after landing.

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