Phosphorylation of SPICK2, an AKT2 channel homologue from Samanea motor cells
SPICK2, a homologue of the weakly-inward-rectifying Shaker-like Arabidopsis K channel, AKT2, is a candidate K+-influx channel participating in light- and clock-regulated leaf movements of the legume, Samanea saman. Light and the biological clock regulate the in situ K+-influx channel activity differ...
| Publié dans: | Journal of experimental botany. - 1985. - 57(2006), 14 vom: 15., Seite 3583-94 |
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| Auteur principal: | |
| Autres auteurs: | , , , , , , , , , |
| Format: | Article |
| Langue: | English |
| Publié: |
2006
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| Accès à la collection: | Journal of experimental botany |
| Sujets: | Journal Article Research Support, Non-U.S. Gov't Enzyme Inhibitors Membrane Proteins Plant Proteins Potassium Channels, Inwardly Rectifying RNA, Messenger Cesium 1KSV9V4Y4I Okadaic Acid plus... |
| Résumé: | SPICK2, a homologue of the weakly-inward-rectifying Shaker-like Arabidopsis K channel, AKT2, is a candidate K+-influx channel participating in light- and clock-regulated leaf movements of the legume, Samanea saman. Light and the biological clock regulate the in situ K+-influx channel activity differentially in extensor and flexor halves of the pulvinus (the S. saman leaf motor organ), and also-though differently-the transcript level of SPICK2 in the pulvinus. This disparity between the in situ channel activity versus its candidate transcript, along with the sequence analysis of SPICK2, suggest an in situ regulation of the activity of SPICK2, possibly by phosphorylation and/or by interaction with cAMP. Consistent with this (i) the activity of the voltage-dependent K+-selective fraction of the inward current in extensor and flexor cells was affected differentially in whole-cell patch-clamp assays promoting phosphorylation (using the protein phosphatase inhibitor okadaic acid); (ii) several proteins in isolated plasma membrane-enriched vesicles of the motor cells underwent phosphorylation without an added kinase in conditions similar to patch-clamp; and (iii) the SPICK2 protein was phosphorylated in vitro by the catalytic subunit of the broad-range cAMP-dependent protein kinase. All of these results are consistent with the notion that SPICK2 is the K+-influx channel, and is regulated in vivo directly by phosphorylation |
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| Description: | Date Completed 27.02.2007 Date Revised 16.11.2017 published: Print-Electronic Citation Status MEDLINE |
| ISSN: | 1460-2431 |