Details

Autor(en) / Beteiligte

• Puri, Sanjeev
• Magenheimer, Brenda S.
• Maser, Robin L.
• Ryan, Erin M.
• Zien, Christopher A.
• Walker, Danielle D.
• Wallace, Darren P.
• Hempson, Scott J.
• Calvet, James P.

Titel

Polycystin-1 Activates the Calcineurin/NFAT (Nuclear Factor of Activated T-cells) Signaling Pathway

Ist Teil von

• The Journal of biological chemistry, 2004-12, Vol.279 (53), p.55455-55464

Ort / Verlag

United States: Elsevier Inc

Erscheinungsjahr

2004

Link zum Volltext

Quelle

Free E-Journal (出版社公開部分のみ）

Beschreibungen/Notizen

• Regulation of intracellular Ca2+ mobilization has been associated with the functions of polycystin-1 (PC1) and polycystin-2 (PC2), the protein products of the PKD1 and PKD2 genes. We have now demonstrated that PC1 can activate the calcineurin/NFAT (nuclear factor of activated T-cells) signaling pathway through Gαq -mediated activation of phospholipase C (PLC). Transient transfection of HEK293T cells with an NFAT promoter-luciferase reporter demonstrated that membrane-targeted PC1 constructs containing the membrane proximal region of the C-terminal tail, which includes the heterotrimeric G protein binding and activation domain, can stimulate NFAT luciferase activity. Inhibition of glycogen synthase kinase-3β by LiCl treatment further increased PC1-mediated NFAT activity. PC1-mediated activation of NFAT was completely inhibited by the calcineurin inhibitor, cyclosporin A. Cotransfection of a construct expressing the Gαq subunit augmented PC1-mediated NFAT activity, whereas the inhibitors of PLC (U73122) and the inositol trisphosphate and ryanodine receptors (xestospongin and 2-aminophenylborate) and a nonspecific Ca2+ channel blocker (gadolinium) diminished PC1-mediated NFAT activity. PC2 was not able to activate NFAT. An NFAT-green fluorescent protein nuclear localization assay demonstrated that PC1 constructs containing the C-tail only or the entire 11-transmembrane spanning region plus C-tail induced NFAT-green fluorescent protein nuclear translocation. NFAT expression was demonstrated in the M-1 mouse cortical collecting duct cell line and in embryonic and adult mouse kidneys by reverse transcriptase-PCR and immunolocalization. These data suggest a model in which PC1 signaling leads to a sustained elevation of intracellular Ca2+ mediated by PC1 activation of Gαq followed by PLC activation, release of Ca2+ from intracellular stores, and activation of store-operated Ca2+ entry, thus activating calcineurin and NFAT.