| Autor: |
Guerra, L., Favia, M., Fanelli, T., Calamita, G., Svelto, M., Bagorda, A., Jacobson, K. A., Reshkin, S. J., Casavola, V. |
| Předmět: |
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| Zdroj: |
Pflügers Archiv: European Journal of Physiology; Oct2004, Vol. 449 Issue 1, p66-75, 10p |
| Abstrakt: |
Nucleotide binding to purinergic P2Y receptors contributes to the regulation of a variety of physiological functions in renal epithelial cells. Here, we investigate the regulatory mechanism of the P2Y1 receptor agonist 2-methylthioadenosine diphosphate (2-MeSADP) on Cl- transport in A6 cells, a commonly used model of the distal section of theXenopus laevisnephron. Protein and mRNA expression analysis together with functional measurements demonstrated the basolateral location of theXenopusP2Y1 receptor. 2-MeSADP increased intracellular [Ca2+] and cAMP and Cl- efflux, responses that were all inhibited by the specific P2Y1 receptor antagonist MRS 2179. Cl- efflux was also inhibited by the cystic fibrosis transmembrane conductance regulator (CFTR) blocker glibenclamide. Inhibition of either protein kinase A (PKA) or the binding between A-kinase-anchoring proteins (AKAPs) and the regulatory PKA RII subunit blocked the 2-MeSADP-induced activation of CFTR, suggesting that PKA mediates P2Y1 receptor regulation of CFTR through one or more AKAPs. Further, the truncation of the PDZ1 domain of the scaffolding protein Na+/H+ exchanger regulatory factor-2 (NHERF-2) inhibited 2-MeSADP-dependent stimulation of Cl- efflux, suggesting the involvement of this scaffolding protein. Activation or inhibition of PKC had no effect per se on basal Cl- efflux but potentiated or reduced the 2-MeSADP-dependent stimulation of Cl- efflux, respectively. These data suggest that theX. laevisP2Y1 receptor in A6 cells can increase both cAMP/PKA and Ca2+/PKC intracellular levels and that the PKC pathway is involved in CFTR activation via potentiation of the PKA pathway. [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
| Externí odkaz: |
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