論文 - 詳細
| RRC ID | 28600 |
|---|---|
| 著者 | Ono Y, Ojima K, Torii F, Takaya E, Doi N, Nakagawa K, Hata S, Abe K, Sorimachi H. |
| タイトル | Skeletal muscle-specific calpain is an intracellular Na+-dependent protease. |
| ジャーナル | J Biol Chem |
| Abstract |
Because intracellular [Na(+)] is kept low by Na(+)/K(+)-ATPase, Na(+) dependence is generally considered a property of extracellular enzymes. However, we found that p94/calpain 3, a skeletal-muscle-specific member of the Ca(2+)-activated intracellular "modulator proteases" that is responsible for a limb-girdle muscular dystrophy ("calpainopathy"), underwent Na(+)-dependent, but not Cs(+)-dependent, autolysis in the absence of Ca(2+). Furthermore, Na(+) and Ca(2+) complementarily activated autolysis of p94 at physiological concentrations. By blocking Na(+)/K(+)-ATPase, we confirmed intracellular autolysis of p94 in cultured cells. This was further confirmed using inactive p94:C129S knock-in (p94CS-KI) mice as negative controls. Mutagenesis studies showed that much of the p94 molecule contributed to its Na(+)/Ca(2+)-dependent autolysis, which is consistent with the scattered location of calpainopathy-associated mutations, and that a conserved Ca(2+)-binding sequence in the protease acted as a Na(+) sensor. Proteomic analyses using Cs(+)/Mg(2+) and p94CS-KI mice as negative controls revealed that Na(+) and Ca(2+) direct p94 to proteolyze different substrates. We propose three roles for Na(+) dependence of p94; 1) to increase sensitivity of p94 to changes in physiological [Ca(2+)], 2) to regulate substrate specificity of p94, and 3) to regulate contribution of p94 as a structural component in muscle cells. Finally, this is the first example of an intracellular Na(+)-dependent enzyme. |
| 巻・号 | 285(30) |
| ページ | 22986-98 |
| 公開日 | 2010-7-23 |
| DOI | 10.1074/jbc.M110.126946 |
| PII | S0021-9258(20)60341-6 |
| PMID | 20460380 |
| PMC | PMC2906292 |
| MeSH | Amino Acid Sequence Animals Autolysis Binding Sites Calcium / metabolism Calcium / pharmacology Calpain / chemistry Calpain / genetics Calpain / metabolism* Enzyme Activation / drug effects Humans Intracellular Space / enzymology* Mice Molecular Sequence Data Muscle, Skeletal / enzymology* Mutation Organ Specificity Protein Structure, Tertiary Rats Sodium / metabolism* Sodium / pharmacology Substrate Specificity |
| IF | 4.238 |
| 引用数 | 33 |
| WOS 分野 | BIOCHEMISTRY & MOLECULAR BIOLOGY |
| オルトメトリクス指標 |
オルトメトリクス指標項目
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| 各媒体での言及数の合計 | 0 |
| リソース情報 | |
| 遺伝子材料 | pcDNA3.1-N-FlagC-humanCAPN3(p94) (RDB08250) pBluescript-human-CAPN3(p94) (RDB08249) |