Inter- and intra-specific variation in myosin light chain and troponin I composition in fast muscle fibres from two species of fish (genusOreochromis) which have different temperature-dependent contractile properties

1991 ◽  
Vol 12 (5) ◽  
pp. 439-446 ◽  
Author(s):  
T. Crockford ◽  
K. E. Wommack ◽  
I. A. Johnston ◽  
B. J. McAndrew ◽  
G. Mutungi ◽  
...  
Keyword(s):  
Light Chain ◽  
Myosin Light Chain ◽  
Troponin I ◽  
Contractile Properties ◽  
Fast Muscle ◽  
Muscle Fibres ◽  
Temperature Dependent ◽  
Specific Variation

Immunocytochemical investigations of muscle differentiation in the Atlantic herring (Clupea harengus: Teleostei)

1994 ◽  
Vol 74 (1) ◽  
pp. 79-91 ◽  
Author(s):  
I. A. Johnston ◽  
Z. Horne
Keyword(s):  
Light Chain ◽  
Myosin Light Chain ◽  
Troponin I ◽  
Troponin T ◽  
Small Diameter ◽  
Fibre Volume ◽  
Clupea Harengus ◽  
Muscle Fibres ◽  
Atlantic Herring ◽  
Superficial Muscle

The myotomes in yolk-sac larvae of the Atlantic herring (Clupea harengus: Teleostei) contain a single layer of small-diameter superficial muscle fibres surrounding an inner mass of around 280 larger-diameter muscle fibres. The fraction of muscle fibre volume occupied by mitochondria is dependent on temperature, and in larvae reared at 8°C was 41% for the superficial fibres, and 25% for the inner muscle fibres. The inner muscle fibres of larvae share some myofibrillar proteins with adult white muscle, but contain unique isoforms of myosin heavy chains, troponin T, troponin I and myosin light chain 2. A monoclonal antibody has been produced which is specific to myosin light chain 3 (MLC3). Immunocytochemical studies have shown that the expression of MLC3 is switched off in the superficial muscle fibres at the start of metamorphosis when larvae reach 28–30 mm total length (TL). Metamorphosis to the juvenile stage is complete in fish 35–40 mm TL and is also associated with the development of gill filaments and the production of presumptive slow muscle fibres which form externally to the larval superficial muscle fibres in the region of the lateral line nerve.

scholarly journals Functionally significant allelic variation in myosin light chain composition in a tropical cichlid

1995 ◽  
Vol 198 (12) ◽  
pp. 2501-2508 ◽  
Author(s):  
T Crockford ◽  
I Johnston ◽  
B Mcandrew
Keyword(s):  
Light Chain ◽  
Myosin Light Chain ◽  
Allelic Variation ◽  
Test Method ◽  
Tropical Fish ◽  
Fast Muscle ◽  
F1 Hybrids ◽  
Relative Molecular Mass ◽  
Muscle Fibres ◽  
Molar Ratios

Single fast muscle fibres in the tropical fish Oreochromis andersonii were found to contain two myosin light chains (LC1s; LC1f1* or LC1f2*). Breeding experiments confirmed that the different LC1s were of allelic origin and their inheritance patterns conformed to Mendelian expectations (1:2:1). The LC1s differed in apparent relative molecular mass by 800­900. No other differences in myosin subunits were found between the LC1 genotypes. The molar ratios of LC3:LC1(total) in the fast muscle of O. andersonii homozygous for LC1f1* or LC1f2* and heterozygous for both alleles were 2.0:1, 2.1:1 and 2.2:1, respectively, as determined by capillary electrophoresis. The maximum contraction velocity (Vmax) of single skinned muscle fibres was determined at 20 °C by the slack-test method. Vmax values (fibre lengths s-1) for fast muscle fibres from O. andersonii which were homozygous for either LC1f2* or LC1f1* were 5.3 and 3.3, respectively, compared with 3.8 when both alleles were present. Crosses between Oreochromis niloticus and O. andersonii produced F1 hybrids which were heterozygous for either LC1n/LC1f1* or LC1n/LC1f2*, where LC1n is the myosin light chain for O. niloticus. The distribution of myosin light chain genotypes in hybrid offspring was not significantly different from the expected Mendelian 1:1 ratio (47 %: 53 %). The Vmax (fibre lengths s-1) of muscle fibres containing LC1f2* from hybrid Oreochromis was 4.3 compared with 3.1 for the LC1f1* genotype. The results are consistent with a functionally significant allelic variation in myosin LC1 in fast muscle fibres from O. andersonii which is also expressed in hybrid genotypes.

Morphometry and muscle gene expression in hypertrophied hearts from polyomavirus large T antigen transgenic mice

1995 ◽  
Vol 269 (1) ◽  
pp. H86-H95 ◽  
Author(s):  
E. Holder ◽  
B. Mitmaker ◽  
L. Alpert ◽  
L. Chalifour
Keyword(s):  
Transgenic Mice ◽  
Myosin Heavy Chain ◽  
Heavy Chain ◽  
Light Chain ◽  
Myosin Light Chain ◽  
Troponin I ◽  
T Antigen ◽  
Large T Antigen ◽  
Cross Sectional

Transgenic mice expressing polyomavirus large T antigen (PVLT) in cardiomyocytes develop a cardiac hypertrophy in adulthood. Morphometric analysis identified cardiomyocytes enlarged up to ninefold in cross-sectional area in the adult transgenic hearts compared with normal age-matched nontransgenic hearts. Most enlarged cardiomyocytes were found in the subendocardium, whereas normal-sized cardiomyocytes were localized to the midmyocardium. Transgenic hearts did not express detectable skeletal muscle actin mRNA or protein, or skeletal troponin I isoform mRNA. Some, but not all, transgenic hearts expressed an increase in the beta-myosin heavy chain mRNA. All five transgenic mice tested had increased expression of atrial natriuretic factor (ANF) mRNA. Whereas normal hearts expressed three myosin light chain proteins of 19, 16, and 15 kDa, we found that the 19-kDa myosin light chain was not observed in the transgenic hearts. We conclude that adult, PVLT-expressing, transgenic mice developed enlarged cardiomyocytes with an increase in beta-myosin heavy chain and ANF mRNA expression, but a widespread skeletal isoform usage was not present in these transgenic mice. The adult transgenic hearts thus display histological and molecular changes similar to those found in hypertrophy induced by a pressure overload in vivo.

scholarly journals Effects of temperature and method of heat treatment on myofibrillar proteins of pork

2014 ◽  
Vol 20 (3) ◽  
pp. 407-415 ◽  
Author(s):  
Dragan Vujadinovic ◽  
Radoslav Grujic ◽  
Vladimir Tomovic ◽  
Aleksandra Torbica
Keyword(s):  
Heat Treatment ◽  
Light Chain ◽  
Myosin Light Chain ◽  
Troponin I ◽  
Troponin T ◽  
Protein S ◽  
Treatment Temperature ◽  
M Protein ◽  
Meat Sample ◽  
Myofibrillar Proteins

During the tests in this paper, meat processing was carried out at different temperatures between the range of 51?C to 100?C. The meat was processed by dry heat (roasting) and wet heat treatments (cooking) in water at atmospheric pressure. After heat treatment, myofibrillar proteins were extracted from solutions at constant ionic strength. Quantitative and qualitative determinations of protein?s fractions were performed by capillary electrophoresis. Myofibrillar proteins were also analized for fresh pork meat sample. Results obtained in fresh meat were compared with those recorded after roasting and cooking. In the fresh and thermally processed pork the following proteins were identified: myosin, light chain 3; myosin, light chain 2; troponin - C; troponin - I; myosin, light chain 1; tropomyosin; troponin - T; actin; desmin; ? - actinin; C - protein; M - protein (M?); M - protein (M?); heavy meromyosin - HMM. For both methods of thermal processing, with increasing heat treatment temperature, concentration of soluble protein in the extract decreases rapidly after 51?C. Cooking treatment had a more intense effect on the proteins change and denaturation than roasting.

scholarly journals Angiotensin Receptor II type 1 and the activation of Myosin Light-Chain Kinase and Protein Kinase C-βII. Mini Review.

2019 ◽  
Author(s):  
Gerry A. Smith
Keyword(s):  
Protein Kinase C ◽  
Protein Kinase ◽  
Light Chain ◽  
Myosin Light Chain Kinase ◽  
Myosin Light Chain ◽  
Troponin I ◽  
Kinase C ◽  
Skeletal Muscle Contraction ◽  
Agonist Property

The involvement of the angiotensin II type 1 receptor in the Frank-Starling Law of the Heart, where the various activations are very limited, allows simple analysis of the kinase systems involved and thence extrapolation of the mechanism to that of angiotensin control of activation of cardiac and skeletal muscle contraction. The involvement of phosphorylation of the myosin light chain in the control of contraction is accepted but not fully understood. The involvement of troponin-I phosphorylation is also indicated but of unknown mechanism. There is no known signal for activation of myosin light chain kinase or Protein Kinase C-βII other than Ca2+/calmodulin but the former is constitutively active and thus has to be under control of a regulated inhibitor the latter kinase may also be the same. Ca2+/calmodulin is not activated in Frank-Starling, i.e. there are no diastolic or systolic [Ca2+] changes. I suggest here that that the regulated inhibition is by myosin light chain phosphatase and/or β-arrestin. Angiotensin activation is by translocation of the β-arrestin from the sarcoplasm to the PM thus reducing its inhibition in the sarcoplasm, this reduced inhibition has been wrongly attributed to a mythical downstream agonist property of β-arrestin.

Determinants of the contractile properties in the embryonic chicken gizzard and aorta

2000 ◽  
Vol 279 (6) ◽  
pp. C1722-C1732 ◽  
Author(s):  
Ozgur Ogut ◽  
Frank V. Brozovich
Keyword(s):  
Smooth Muscle ◽  
Light Chain ◽  
Myosin Light Chain ◽  
Smooth Muscles ◽  
Contractile Properties ◽  
In Vitro Motility ◽  
Force Maintenance ◽  
Isoform Expression ◽  
Force Activation

Smooth muscle is generally grouped into two classes of differing contractile properties. Tonic smooth muscles show slow rates of force activation and relaxation and slow speeds of shortening ( V max) but force maintenance, whereas phasic smooth muscles show poor force maintenance but have fast V max and rapid rates of force activation and relaxation. We characterized the development of gizzard and aortic smooth muscle in embryonic chicks to identify the cellular determinants that define phasic (gizzard) and tonic (aortic) contractile properties. Early during development, tonic contractile properties are the default for both tissues. The gizzard develops phasic contractile properties between embryonic days ( ED) 12 and 20, characterized primarily by rapid rates of force activation and relaxation compared with the aorta. The rapid rate of force activation correlates with expression of the acidic isoform of the 17-kDa essential myosin light chain (MLC17a). Previous data from in vitro motility assays (Rover AS, Frezon Y, and Trybus KM. J Muscle Res Cell Motil 18: 103–110, 1997) have postulated that myosin heavy chain (MHC) isoform expression is a determinant for V max in intact tissues. In the current study, differences in V max did not correlate with previously published differences in MHC or MLC17a isoforms. Rather, V max was increased with thiophosphorylation of the 20-kDa regulatory myosin light chain (MLC20) in the gizzard, suggesting that a significant internal load exists. Furthermore, V max in the gizzard increased during postnatal development without changes in MHC or MLC17 isoforms. Although the rate of MLC20 phosphorylation was similar at ED 20, the rate of MLC20 dephosphorylation was significantly higher in the gizzard versus the aorta, correlating with expression of the M130 isoform of the myosin binding subunit in the myosin light chain phosphatase (MLCP) holoenzyme. These results indicate that unique MLCP and MLC17 isoform expression marks the phasic contractile phenotype.

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