https://scholars.lib.ntu.edu.tw/handle/123456789/424755
Title: | Alpha-kinase 1, a new component in apical protein transport | Authors: | Heine, Martin Cramm-Behrens, Catharina I Ansari, Athar HSUEH-PING CHU Ryazanov, Alexey G Naim, Hassan Y Jacob, Ralf |
Issue Date: | 8-Jul-2005 | Journal Volume: | 280 | Journal Issue: | 27 | Start page/Pages: | 25637-25643 | Source: | The Journal of biological chemistry | Abstract: | A key aspect in the structure of epithelial cells is the maintenance of a polarized organization based on a highly specific sorting machinery for cargo destined for the apical or the basolateral membrane domain at the exit site of the trans-Golgi network. We could recently identify two distinct post-trans-Golgi network vesicle populations that travel along separate routes to the plasma membrane, a lipid raft-dependent and a lipid raft-independent pathway. A new component of raft-carrying apical vesicles is alpha-kinase 1 (ALPK1), which was identified in immunoisolated vesicles carrying raft-associated sucrase-isomaltase (SI). This kinase was absent from vesicles carrying raft-non-associated lactase-phlorizin hydrolase. The expression of ALPK1 increases by the time of epithelial cell differentiation, whereas the intracellular localization of ALPK1 on apical transport vesicles was confirmed by confocal analysis. A phosphorylation assay on isolated SI-carrying vesicles revealed the phosphorylation of a protein band of about 105 kDa, which could be identified as the motor protein myosin I. Finally, a specific reduction of ALPK1-expression by RNA interference results in a significant decrease in the apical delivery of SI. Taken together, our data suggest that the phosphorylation of myosin I by ALPK1 is an essential process in the apical trafficking of raft-associated SI. |
URI: | https://scholars.lib.ntu.edu.tw/handle/123456789/424755 | ISSN: | 0021-9258 | DOI: | https://api.elsevier.com/content/abstract/scopus_id/21844442358 10.1074/jbc.M502265200 |
Appears in Collections: | 分子與細胞生物學研究所 |
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J. Biol. Chem.-2005-Heine-25637-43.pdf | 565.46 kB | Adobe PDF | View/Open |
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