| Autor: |
Raynaud F; UMR5539, EPHE-CNRS-UM2, cc107, Université Montpellier II, place E. Bataillon, 34095 Montpellier cedex 5, France. raynaudf@univ-montp2.fr, Jond-Necand C, Marcilhac A, Fürst D, Benyamin Y |
| Jazyk: |
angličtina |
| Zdroj: |
The international journal of biochemistry & cell biology [Int J Biochem Cell Biol] 2006 Mar; Vol. 38 (3), pp. 404-13. Date of Electronic Publication: 2005 Oct 27. |
| DOI: |
10.1016/j.biocel.2005.09.020 |
| Abstrakt: |
Calpains are a family of calcium-dependent cysteine-proteases involved in cytoskeleton remodelling and muscle differentiation. In a recent study, we observed the presence of calpain 1 in the muscle contractile apparatus and specifically in the N1- and N2-lines. This calpain isoform was found to be involved in the degradation of muscle fibres via proteolysis of key proteins in Z-disk and costameric junctions. The goal of this study was to determine whether gamma-filamin--a specific muscle isoform of the filamin family--is a calpain 1 substrate and to characterise this interaction. Gamma-filamin is a major muscle architectural protein located in the Z-line and under the sarcolemmal membrane. This protein is a component of the chain binding the sarcolemma to the sarcomeric structure. In this study, we found that gamma-filamin formed a stable complex in vitro and in cells with calpain 1 in the absence of calcium stimulation. We also located the binding domains in the C-terminus of gamma-filamin with a cleavage site between serine 2626 and serine 2627 in the hinge 2 region. The catalytic (80 kDa) and regulatory (28 kDa) subunits of calpain 1 are both involved in high affinity binding at gamma-filamin. Moreover, we showed that phosphorylation of the filamin C-terminus domain by PKC alpha protected gamma-filamin against proteolysis by calpain 1 in COS cells. Stimulation of PKC activity in myotubes, prevented gamma-filamin proteolysis by calpain and resulted in an increase in myotube adhesion. |
| Databáze: |
MEDLINE |
| Externí odkaz: |
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