Myosin isoforms in anuran skeletal muscle: Their influence on contractile properties and in vivo muscle function

  title={Myosin isoforms in anuran skeletal muscle: Their influence on contractile properties and in vivo muscle function},
  author={Gordon Lutz and Richard L. Lieber},
  journal={Microscopy Research and Technique},
  • G. Lutz, R. Lieber
  • Published 15 September 2000
  • Biology
  • Microscopy Research and Technique
Functional studies on isolated single anuran skeletal muscle cells represent classic experiments from which much of our understanding of muscle contraction mechanisms have been derived. Because of their superb mechanical stability when isolated, single anuran fibers provide a uniquely powerful model system that can be exploited to understand the relationship between myosin heavy chain (MHC) and myosin light chain (MLC) composition and muscle fiber function. In this review, we summarize historic… 

Studies of myosin isoforms in muscle cells: single cell mechanics and gene transfer.

The current authors summarize recent studies defining the myosin isoforms in muscle from frogs and the relationship between myosIn isoforms and mechanical performance of intact single muscle cells and the potential for simple plasmid-based in vivo gene transfer approaches to elucidate the structural basis of muscle protein function in intact cells.

The motor protein myosin in skeletal muscle is a hexameric polypeptide consisting of two myosin heavy chain (MHC)

Frog muscle is unique in that relatively long, single, intact ‘living’ fibres can be isolated that retain excellent mechanical stability and from which sarcomere length transients can readily be measured by laser diffraction.

Influence of myosin isoforms on contractile properties of intact muscle fibers from Rana pipiens.

The force-velocity properties of single intact fast-twitch fibers from R. pipiens that contained MHC types 1 or 2 or coexpressed MHC1 and MHC2 isoforms are measured to demonstrate the powerful relationship between MHC isoforms and F-V properties of the two most common Rana pipiens fiber types.

In vivo expression of myosin essential light chain using plasmid expression vectors in regenerating frog skeletal muscle

The feasibility of using in vivo gene transfer to probe the structural basis of contractile protein function in skeletal muscle is demonstrated and further improvements in the level and consistency of myosin transgene expression may be achieved in future studies are discussed.

Electrophoretic and functional identification of two troponin C isoforms in toad skeletal muscle fibers.

The Ca(2+) activation properties of toad fibers containing the TnC-T/c isoform appear to be consistent with the previously reported physiological characteristics of amphibian slow-tonic muscle fibers.

Identification of myosin light chains in Rana pipiens skeletal muscle and their expression patterns along single fibres.

The intraspecific polymorphism in MLC1 expression is likely to have a genetic basis, but the correlation between segments was weaker than between fibres, and is unlikely to be caused by allelic variation.

Limited expression of slow tonic myosin heavy chain in human cranial muscles

It is suggested that reports of MHCst in human masticatory and laryngeal muscles reflect false‐positive identification of M HCst due to cross‐reactivity of Ab ALD‐58 with another MHC isoform.

Comparative trends in shortening velocity and force production in skeletal muscles.

  • S. Medler
  • Biology
    American journal of physiology. Regulatory, integrative and comparative physiology
  • 2002
Overall, the contractile properties of skeletal muscles are conserved among phylogenic groups, but have been significantly influenced by other factors such as body size and mode of locomotion.

The genome of the diploid anuran Xenopus tropicalis contains a novel array of sarcoplasmic myosin heavy chain genes expressed in larval muscle and larynx

Genetic organization of MyHC isoforms may be highly conserved across tetrapods, and duplication of the fast-skeletal MyHC array appears to have led to expression divergence of muscle proteins in the larval and adult stages of the anuran life cycle.

Plasticity of skeletal muscle phenotype: Mechanical consequences

A discussion of those factors (i.e., factors 2–5) that appear to be highly malleable in the work‐loop technique to provide a more realistic approach toward understanding muscle function.



Four novel myosin heavy chain transcripts define a molecular basis for muscle fibre types in Ranapipiens

Comparison of sequence homology among amphibian, avian and mammalian MHC families supports the concept of independent evolution of fast MHC genes within vertebrate classes subsequent to the amphibian/avian/mammalian radiation.

Some advances in integrative muscle physiology.

  • L. Rome
  • Biology
    Comparative biochemistry and physiology. Part B, Biochemistry & molecular biology
  • 1998

Mechanical properties and myosin heavy chain isoform composition of skinned skeletal muscle fibres from a human biopsy sample

The distribution of shortening velocity and kinetics of stretch activation values suggest that two muscle fibre subtypes may exist in human type I fibres, similar to that in myosin heavy chain.

Type 2X-myosin heavy chain is coded by a muscle fiber type-specific and developmentally regulated gene

In situ hybridization analyses show that 2X-MyHC transcripts are expressed at high levels in the diaphragm and fast hindlimb muscles and can be coexpressed either with 2B- or 2A- MyHC transcripts in a number of fibers.

Structural properties of frog muscle myosin.

Physiological effects accompanying the removal of myosin LC2 from skinned skeletal muscle fibers.

ATPase Activity of Myosin Correlated with Speed of Muscle Shortening

  • M. Bárány
  • Biology, Chemistry
    The Journal of general physiology
  • 1967
A role for the ATPase activity of myosin in determining the speed of muscle contraction is suggested and the F-actin-binding ability of myOSin from various muscles was rather constant.

Unloaded shortening velocity and myosin heavy chain and alkali light chain isoform composition in rat skeletal muscle fibres.

The maximum velocity of shortening as determined by the slack test (Vo) was tested for its relationship with MHC composition and with alkali MLC isoform ratio of fast fibres of known M HC composition and was found to be proportional to the relative content of MLC3f in IIA, IIX and IIB fibres.

Quantitative analyses of myosin heavy-chain mRNA and protein isoforms in single fibers reveal a pronounced fiber heterogeneity in normal rabbit muscles.

The detection of high amounts of IIBD and IIDB fibers suggested that hybrid fibers represent functional elements within the fiber spectrum of normal muscles, and an unexpected heterogeneity of the fast fiber population with regard to numerous fibers coexpressing MHCIIb and MHCiid/x.