The Role of Calpastatin (the Specific Calpain Inhibitor) in Myoblast Differentiation and Fusion

Barnoy, Sivia; Glaser, Tova; Kosower, Nechama S.

doi:10.1006/bbrc.1996.0509

Cited by 66 publications

(52 citation statements)

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“…For some proteins, there is a transient increase during differentiation, followed by diminution in the myotubes, as observed for 2h,5h-oligoadenylate synthetase (2,5A synthetase) [31] and cathepsin B [32]. Other proteins are transiently diminished before myoblast fusion, as observed for calpastatin [10] and insulin growth factor-binding protein 3 (IGFBP-3) [33].…”

Section: Discussionmentioning

confidence: 92%

“…Using red cells as an experimental model, it was found that the cell fusibility depended on the ratio of calpain to calpastatin [4,6]. In a study on rat L8 myoblast fusion, we found that the µ-calpain and m-calpain levels did not change significantly during myoblast differentiation, whereas calpastatin diminished markedly prior to myoblast fusion and reappeared after fusion [10]. A selective, limited, calpain-induced degradation of some cytoskeletal and membrane proteins was observed in the L8 fusing myoblasts [14].…”

Section: Introductionmentioning

confidence: 93%

“…The cells were grown in 0.1 % gelatin-coated 90-mm Petri dishes in Waymouth medium, supplemented by 15 % fetal calf serum, 1 % antibiotics and 1 % glutamine (growth medium, GM), and induced to differentiate, according to the procedures described previously [10]. When the cells reached 50 % confluency, the medium was changed to Dulbecco's modified Eagle's medium, supplemented by 2 % horse serum, 1 % antibiotics, 1 % glutamine and 4 units of insulin\100 ml of medium (differentiation medium, DM).…”

Section: Myoblast Cultures and Inhibition Of Myoblast Fusion And Protmentioning

confidence: 99%

“…A limited membrane-protein degradation appears to be required for cell fusion, a degradation that would allow membrane disorganization in fusing cells [1][2][3][4][5][6]. It has been proposed that calpain (Ca# + -dependent intracellular protease) is involved in the fusion-associated protein degradation [4][5][6][7][8][9][10][11]. Most cells, in addition to having one or more of the known calpain isoenzymes, contain the specific inhibitor calpastatin, with ratios of calpain to calpastatin varying among different tissues and cell types [12,13].…”

Section: Introductionmentioning

confidence: 99%

“…The overall results indicate that the decreased stability of calpastatin protein, along with inhibition of calpastatin synthesis, lead to the diminution of calpastatin in the differentiating myoblasts, prior to fusion. The transient diminution of calpastatin protein [10] and of its mRNA may be part of the myogenic programme responsible for myoblast differentiation [18].…”

Section: Introductionmentioning

confidence: 99%

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Regulation of calpain and calpastatin in differentiating myoblasts: mRNA levels, protein synthesis and stability

Barnoy

Supino-Rosin

Kosower

2000

Biochemical Journal

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Tel Aviv 69978, IsraelCalpain (Ca# + -dependent intracellular protease)-induced proteolysis has been considered to play a role in myoblast fusion to myotubes. We found previously that calpastatin (the endogenous inhibitor of calpain) diminishes transiently during myoblast differentiation. To gain information about the regulation of calpain and calpastatin in differentiating myoblasts, we evaluated the stability and synthesis of calpain and calpastatin, and measured their mRNA levels in L8 myoblasts. We show here that µ-calpain and m-calpain are stable, long-lived proteins in both dividing and differentiating L8 myoblasts. Calpain is synthesized in differentiating myoblasts, and calpain mRNA levels do not change during differentiation. In contrast, calpastatin (though also a long-lived protein in myoblasts), is less stable in differentiating myoblasts than in the dividing cells, and its synthesis is inhibited upon initiation of differentiation. Inhibition of cal-

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Section: Discussionmentioning

confidence: 92%

Section: Introductionmentioning

confidence: 93%

Section: Myoblast Cultures and Inhibition Of Myoblast Fusion And Protmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Regulation of calpain and calpastatin in differentiating myoblasts: mRNA levels, protein synthesis and stability

Barnoy

Supino-Rosin

Kosower

2000

Biochemical Journal

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Effects of thiol protease inhibitors on myoblast fusion and myofibril assembly in vitro

Moncman¹,

Wang²

1998

Cell Motil. Cytoskeleton

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To investigate the roles of thiol proteases such as cathepsins and calpains in muscle differentiation, we have treated primary cultures of pectoralis muscle with a variety of protease inhibitors and examined the effects these agents have on myoblast fusion and myofibrillogenesis. We have found that a membrane‐permeable inhibitor, E64D, has dramatic effects on both events of muscle differentiation. Cells treated with this inhibitor display gross morphological changes, severe delays in myofibril assembly, and reduced ability to fuse in culture. These morphological changes are correlated with a build up of β1‐integrin throughout the cytoplasm. These effects could also be produced using NH4Cl, a lysosomotrophic agent. In addition, we show that two nonpermeable inhibitors (leupeptin and E64) slightly decrease myoblast fusion, but have no effects on the ability of the cells to form mature myofibrils. These results are discussed in terms of their relevance to the inheritable disease of muscular dystrophy and I‐cell disease (mucolipodosis II). Cell Motil. Cytoskeleton 40:354–367, 1998. © 1998 Wiley‐Liss, Inc.

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Fusomorphogenesis: Cell fusion in organ formation

Shemer

Podbilewicz

2000

Dev. Dyn.

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The Role of Calpastatin (the Specific Calpain Inhibitor) in Myoblast Differentiation and Fusion

Cited by 66 publications

References 0 publications

Regulation of calpain and calpastatin in differentiating myoblasts: mRNA levels, protein synthesis and stability

Regulation of calpain and calpastatin in differentiating myoblasts: mRNA levels, protein synthesis and stability

Effects of thiol protease inhibitors on myoblast fusion and myofibril assembly in vitro

Fusomorphogenesis: Cell fusion in organ formation

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