論文 - 詳細
| RRC ID | 42333 |
|---|---|
| 著者 | Matsushita M, Kozak JA, Shimizu Y, McLachlin DT, Yamaguchi H, Wei FY, Tomizawa K, Matsui H, Chait BT, Cahalan MD, Nairn AC. |
| タイトル | Channel function is dissociated from the intrinsic kinase activity and autophosphorylation of TRPM7/ChaK1. |
| ジャーナル | J Biol Chem |
| Abstract |
TRPM7/ChaK1 is a unique channel/kinase that contains a TRPM channel domain with 6 transmembrane segments fused to a novel serine-threonine kinase domain at its C terminus. The goal of this study was to investigate a possible role of kinase activity and autophosphorylation in regulation of channel activity of TRPM7/ChaK1. Residues essential for kinase activity were identified by site-directed mutagenesis. Two major sites of autophosphorylation were identified in vitro by mass spectrometry at Ser(1511) and Ser(1567), and these sites were found to be phosphorylated in intact cells. TRPM7/ChaK1 is a cation-selective channel that exhibits strong outward rectification and inhibition by millimolar levels of internal [Mg(2+)]. Mutation of the two autophosphorylation sites or of a key catalytic site that abolished kinase activity did not alter channel activity measured by whole-cell recording or Ca(2+) influx. Inhibition by internal Mg(2+) was also unaffected in the autophosphorylation site or "kinase-dead" mutants. Moreover, kinase activity was enhanced by Mg(2+), was decreased by Zn(2+), and was unaffected by Ca(2+). In contrast, channel activity was inhibited by all three of these divalent cations. However, deletion of much of C-terminal kinase domain resulted in expression of an apparently inactive channel. We conclude that neither current activity nor regulation by internal Mg(2+) is affected by kinase activity or autophosphorylation but that the kinase domain may play a structural role in channel assembly or subcellular localization. |
| 巻・号 | 280(21) |
| ページ | 20793-803 |
| 公開日 | 2005-5-27 |
| DOI | 10.1074/jbc.M413671200 |
| PII | S0021-9258(20)64084-4 |
| PMID | 15781465 |
| MeSH | Amino Acid Sequence Animals Binding Sites Calcium / metabolism Calcium / pharmacology Cations, Divalent Cell Line Crystallization Electric Conductivity Escherichia coli / genetics Gene Expression Ion Channels / chemistry Ion Channels / genetics Ion Channels / physiology* Magnesium / pharmacology Mass Spectrometry Membrane Proteins / chemistry Membrane Proteins / genetics Membrane Proteins / physiology* Mice Molecular Sequence Data Mutagenesis, Site-Directed Patch-Clamp Techniques Phosphorylation Protein Kinases / chemistry Protein Kinases / genetics Protein Kinases / metabolism* Protein Kinases / physiology* Recombinant Fusion Proteins Spodoptera Structure-Activity Relationship TRPM Cation Channels Zinc / pharmacology |
| IF | 4.238 |
| 引用数 | 125 |
| 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 |
| 過去6か月間でのオルトメトリクス指標の変動値 | 0.0 |
| リソース情報 | |
| ヒト・動物細胞 | |