Waldegger, S; Raber, G; Sussbrich, H; Ruppersberg, J P; Fakler, B; Murer, H; Lang, F; Busch, A E (1996). Coexpression and stimulation of parathyroid hormone receptor positively regulates slowly activating IsK channels expressed in Xenopus oocytes. Kidney International, 49(1):112-116.
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Expression of the IsK protein in Xenopus oocytes induced the characteristically slow, voltage-dependent outward currents. Superfusion with the parathyroid hormone (PTH) peptide 1-34 had no effect on IsK when expressed alone, but increased IsK when IsK was coexpressed with the PTH-receptor. PTH receptor stimulation caused a shift of IsK conductance-voltage relationship to more negative potentials, and a decrease of both the rate of IsK activation and deactivation. IsK regulation by PTH was independent of extracellular Ca2+, and was also present IsK protein mutants lacking the protein kinase C consensus site. However, regulation of IsK by PTH was mimicked by activators of protein kinase A (PKA) and greatly reduced in the presence of the kinase inhibitors staurosporine and H89. These results suggest that PTH regulates IsK by a mechanism involving phosphorylation independent of protein kinase C (PKC). Such regulation may play a role in proximal tubule cells of the kidney, where both PTH receptor and the IsK protein are expressed.
|Item Type:||Journal Article, refereed|
|Communities & Collections:||04 Faculty of Medicine > Institute of Physiology|
07 Faculty of Science > Institute of Physiology
|DDC:||570 Life sciences; biology|
|Date:||01 January 1996|
|Deposited On:||11 Feb 2008 13:22|
|Last Modified:||23 Nov 2012 15:28|
|Publisher:||Nature Publishing Group|
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