Localization of calpain 3 in human skeletal muscle and its alteration in limb-girdle muscular dystrophy 2A muscle.

Abstract

Calpain 3/p94, the skeletal muscle-specific isoform of the calpain large subunit family, is a protein product of the gene responsible for limb-girdle muscular dystrophy type 2A (LGMD2A). Through yeast two-hybrid experiments, calpain 3 has been shown to bind to titin in myofibrils [Sorimachi et al. (1995) J. Biol. Chem. 270, 31158-31162]. However, because of extensive autolysis activity, calpain 3 localization in skeletal muscle has been undefined. In this study, we generated a polyclonal antibody against an N-terminal 98-amino-acid calpain 3 fragment, which is not homologous to the corresponding regions of other conventional calpains. This antibody stained myofibrils with a unique repeated doublet-pattern. Confocal microscopic observation with marker antibodies confirmed that calpain 3 is localized in the N2 region of myofibrils. Furthermore, using this antibody, we examined the localization of calpain 3 in LGMD2A muscles.

• Authors: Yoko Keira, Satoru Noguchi, Narihiro Minami, Yukiko K Hayashi, Ichizo Nishino
• Journal: Journal of biochemistry (J Biochem) Vol. 133 Issue 5 Pg. 659-64 (May 2003) ISSN: 0021-924X [Print] England
• PMID: 12801918 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• Isoenzymes
• Muscle Proteins
• CAPN3 protein, human
• Calpain

Topics

• Calpain (metabolism)
• Fluorescent Antibody Technique
• Humans
• Isoenzymes
• Microscopy, Confocal
• Muscle Proteins
• Muscle, Skeletal (enzymology, pathology, ultrastructure)
• Muscular Dystrophies (enzymology, pathology)
• Myofibrils (chemistry, enzymology, ultrastructure)
• Subcellular Fractions (enzymology)