Details

Autor(en) / Beteiligte

• Zhang, Xuexin
• Pathak, Trayambak
• Yoast, Ryan
• Emrich, Scott
• Xin, Ping
• Nwokonko, Robert M.
• Johnson, Martin
• Wu, Shilan
• Delierneux, Céline
• Gueguinou, Maxime
• Hempel, Nadine
• Putney, James W.
• Gill, Donald L.
• Trebak, Mohamed

Titel

A calcium/cAMP signaling loop at the ORAI1 mouth drives channel inactivation to shape NFAT induction

Ist Teil von

• Nature communications, 2019-04, Vol.10 (1), p.1971-13, Article 1971

Ort / Verlag

London: Nature Publishing Group UK

Erscheinungsjahr

2019

Quelle

MEDLINE

Beschreibungen/Notizen

• ORAI1 constitutes the store-operated Ca 2+ release-activated Ca 2+ (CRAC) channel crucial for life. Whereas ORAI1 activation by Ca 2+ -sensing STIM proteins is known, still obscure is how ORAI1 is turned off through Ca 2+ -dependent inactivation (CDI), protecting against Ca 2+ toxicity. Here we identify a spatially-restricted Ca 2+ /cAMP signaling crosstalk critical for mediating CDI. Binding of Ca 2+ -activated adenylyl cyclase 8 (AC8) to the N-terminus of ORAI1 positions AC8 near the mouth of ORAI1 for sensing Ca 2+ . Ca 2+ permeating ORAI1 activates AC8 to generate cAMP and activate PKA. PKA, positioned by AKAP79 near ORAI1, phosphorylates serine-34 in ORAI1 pore extension to induce CDI whereas recruitment of the phosphatase calcineurin antagonizes the effect of PKA. Notably, CDI shapes ORAI1 cytosolic Ca 2+ signature to determine the isoform and degree of NFAT activation. Thus, we uncover a mechanism of ORAI1 inactivation, and reveal a hitherto unappreciated role for inactivation in shaping cellular Ca 2+ signals and NFAT activation. ORAI1 constitutes the store-operated Ca 2+ release-activated Ca 2+ (CRAC) channel, but how this channel is turned off through Ca 2+ -dependent inactivation (CDI) remained unclear. Here the authors identify a spatially-restricted Ca 2+ /cAMP signaling crosstalk critical for mediating CDI which in turn regulates cellular Ca 2+ signals and NFAT activation.