Abstract
p94/calpain 3, a skeletal muscle-specific member of calpain protease family, is characterized by apparent Ca(2+)-independence during exhaustive autolysis and concomitant proteolysis of non-self substrates. The purpose of our study was to comprehensively profile the structural basis of p94 enabling activation in the cytosol without an extra Ca(2+). Ca(2+)-dependent p94 mutants were screened using "p94-trapping", which is an application of yeast genetic reporter system called "proteinase-trapping". Several amino acids were revealed as critical for apparent Ca(2+)-independent p94 activity. These results highlight the importance of conserved amino acids in domain IIb as well as in the p94-specific IS2 region.
Publication types
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Research Support, Non-U.S. Gov't
MeSH terms
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Amino Acid Sequence
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Animals
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COS Cells
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Calcium / pharmacology
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Calpain / chemistry*
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Calpain / isolation & purification
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Calpain / metabolism*
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Chlorocebus aethiops
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Conserved Sequence*
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Models, Molecular
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Molecular Sequence Data
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Muscle Proteins / chemistry*
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Muscle Proteins / isolation & purification
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Muscle Proteins / metabolism*
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Mutant Proteins / chemistry
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Mutant Proteins / isolation & purification
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Mutant Proteins / metabolism
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Mutation / genetics
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Peptide Hydrolases / chemistry*
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Peptide Hydrolases / metabolism*
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Protein Processing, Post-Translational* / drug effects
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Protein Structure, Tertiary
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Sodium / pharmacology
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Structure-Activity Relationship
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Substrate Specificity / drug effects
Substances
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Muscle Proteins
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Mutant Proteins
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Sodium
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Peptide Hydrolases
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CAPN3 protein, human
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Calpain
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Calcium