scholarly journals Innervation-dependent and fiber type-specific transcriptional regulation of the slow myosin heavy chain 2 promoter in avian skeletal muscle fibers

2004 ◽  
Vol 231 (2) ◽  
pp. 292-302 ◽  
Author(s):  
Hongbin Jiang ◽  
Theresa Jordan ◽  
Jinyuan Li ◽  
Hui Li ◽  
Joseph X. DiMario
Keyword(s):  
Skeletal Muscle ◽  
Transcriptional Regulation ◽  
Myosin Heavy Chain ◽  
Heavy Chain ◽  
Fiber Type ◽  
Muscle Fibers ◽  
Slow Myosin ◽  
Skeletal Muscle Fibers ◽  
Slow Myosin Heavy Chain

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

1993 ◽  
Vol 123 (4) ◽  
pp. 823-835 ◽  
Author(s):  
C DeNardi ◽  
S Ausoni ◽  
P Moretti ◽  
L Gorza ◽  
M Velleca ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Myosin Heavy Chain ◽  
Heavy Chain ◽  
Muscle Development ◽  
Fiber Type ◽  
Muscle Fibers ◽  
Hindlimb Muscles ◽  
Isolation And Characterization ◽  
Skeletal Muscle Fibers ◽  
Myhc Isoforms

We have previously reported the identification of a distinct myosin heavy chain (MyHC) isoform in a major subpopulation of rat skeletal muscle fibers, referred to as 2X fibers (Schiaffino, S., L. Gorza, S. Sartore, L. Saggin, M. Vianello, K. Gundersen, and T. Lømo. 1989. J. Muscle Res. Cell Motil. 10:197-205). However, it was not known whether 2X-MyHC is the product of posttranslational modification of other MyHCs or is coded by a distinct mRNA. We report here the isolation and characterization of cDNAs coding a MyHC isoform that is expressed in type 2X skeletal muscle fibers. 2X-MyHC transcripts differ from other MyHC transcripts in their restriction map and 3' end sequence and are thus derived from a distinct 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. At the single fiber level the distribution of each MyHC mRNA closely matches that of the corresponding protein, determined by specific antibodies on serial sections. In hindlimb muscles 2X-, 2A-, and 2B-MyHC transcripts are first detected by postnatal day 2-5 and display from the earliest stages a distinct pattern of distribution in different muscles and different fibers. The emergence of type 2 MyHC isoforms thus defines a distinct neonatal phase of fiber type differentiation during muscle development. The functional significance of MyHC isoforms is discussed with particular reference to the velocity of shortening of skeletal muscle fibers.

scholarly journals A Calcineurin-NFATc3-Dependent Pathway Regulates Skeletal Muscle Differentiation and Slow Myosin Heavy-Chain Expression

2000 ◽  
Vol 20 (17) ◽  
pp. 6600-6611 ◽  
Author(s):  
Ulrike Delling ◽  
Jolana Tureckova ◽  
Hae W. Lim ◽  
Leon J. De Windt ◽  
Peter Rotwein ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Signal Transduction ◽  
Gene Transfer ◽  
Myosin Heavy Chain ◽  
Heavy Chain ◽  
Myogenic Differentiation ◽  
Fiber Type ◽  
Slow Myosin ◽  
Slow Myosin Heavy Chain ◽  
Myocyte Differentiation

ABSTRACT The differentiation and maturation of skeletal muscle cells into functional fibers is coordinated largely by inductive signals which act through discrete intracellular signal transduction pathways. Recently, the calcium-activated phosphatase calcineurin (PP2B) and the family of transcription factors known as NFAT have been implicated in the regulation of myocyte hypertrophy and fiber type specificity. Here we present an analysis of the intracellular mechanisms which underlie myocyte differentiation and fiber type specificity due to an insulinlike growth factor 1 (IGF-1)–calcineurin–NFAT signal transduction pathway. We demonstrate that calcineurin enzymatic activity is transiently increased during the initiation of myogenic differentiation in cultured C2C12 cells and that this increase is associated with NFATc3 nuclear translocation. Adenovirus-mediated gene transfer of an activated calcineurin protein (AdCnA) potentiates C2C12 and Sol8 myocyte differentiation, while adenovirus-mediated gene transfer of noncompetitive calcineurin-inhibitory peptides (cain or ΔAKAP79) attenuates differentiation. AdCnA infection was also sufficient to rescue myocyte differentiation in an IGF-depleted myoblast cell line. Using 10T1/2 cells, we demonstrate that MyoD-directed myogenesis is dramatically enhanced by either calcineurin or NFATc3 cotransfection, while a calcineurin inhibitory peptide (cain) blocks differentiation. Enhanced myogenic differentiation directed by calcineurin, but not NFATc3, preferentially specifies slow myosin heavy-chain expression, while enhanced differentiation through mitogen-activated protein kinase kinase 6 (MKK6) promotes fast myosin heavy-chain expression. These data indicate that a signaling pathway involving IGF-calcineurin-NFATc3 enhances myogenic differentiation whereas calcineurin acts through other factors to promote the slow fiber type program.

scholarly journals Innervation regulates myosin heavy chain isoform expression in developing skeletal muscle fibers

1996 ◽  
Vol 58 (1-2) ◽  
pp. 115-127 ◽  
Author(s):  
Bruno Lefeuvre ◽  
Fe´lix Crossin ◽  
Josiane Fontaine-Pe´rus ◽  
Everett Bandman ◽  
Marie-France Gardahaut
Keyword(s):  
Skeletal Muscle ◽  
Myosin Heavy Chain ◽  
Heavy Chain ◽  
Muscle Fibers ◽  
Myosin Heavy Chain Isoform ◽  
Skeletal Muscle Fibers ◽  
Isoform Expression

Single-fiber myosin heavy chain polymorphism: how many patterns and what proportions?

2003 ◽  
Vol 285 (3) ◽  
pp. R570-R580 ◽  
Author(s):  
Vincent J. Caiozzo ◽  
Michael J. Baker ◽  
Karen Huang ◽  
Harvey Chou ◽  
Ya Zhen Wu ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Myosin Heavy Chain ◽  
Heavy Chain ◽  
Muscle Fibers ◽  
Myosin Heavy Chain Isoforms ◽  
Single Fiber ◽  
Myosin Heavy Chain Isoform ◽  
Skeletal Muscle Fibers ◽  
Velocity Relationship ◽  
Force Velocity

Previous studies have reported the existence of skeletal muscle fibers that coexpress multiple myosin heavy chain isoforms. These surveys have usually been limited to studying the polymorphic profiles of skeletal muscle fibers from a limited number of muscles (i.e., usually <4). Additionally, few studies have considered the functional implications of polymorphism. Hence, the primary objective of this study was to survey a relatively large number of rat skeletal muscle/muscle regions and muscle fibers ( n≈ 5,000) to test the hypothesis that polymorphic fibers represent a larger fraction of the total pool of fibers than do so-called monomorphic fibers, which express only one myosin heavy chain isoform. Additionally, we used Hill's statistical model of the force-velocity relationship to differentiate the functional consequences of single-fiber myosin heavy chain isoform distributions found in these muscles. The results demonstrate that most muscles and regions of rodent skeletal muscles contain large proportions of polymorphic fibers, with the exception of muscles such as the slow soleus muscle and white regions of fast muscles. Several muscles were also found to have polymorphic profiles that are not consistent with the I↔IIA↔IIX↔IIB scheme of muscle plasticity. For instance, it was found that the diaphragm muscle normally contains I/IIX fibers. Functionally, the high degree of polymorphism may 1) represent a strategy for producing a spectrum of contractile properties that far exceeds that simply defined by the presence of four myosin heavy chain isoforms and 2) result in relatively small differences in function as defined by the force-velocity relationship.

Myosin heavy chain expression within the tapered ends of skeletal muscle fibers

1995 ◽  
Vol 242 (4) ◽  
pp. 462-470 ◽  
Author(s):  
Benjamin W. C. Rosser ◽  
Donna M. Waldbillig ◽  
Stacey D. Lovo ◽  
Jacalyn D. Armstrong ◽  
Everett Bandman
Keyword(s):  
Skeletal Muscle ◽  
Myosin Heavy Chain ◽  
Heavy Chain ◽  
Muscle Fibers ◽  
Skeletal Muscle Fibers
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