RACK1 binds to inositol 1,4,5-trisphosphate receptors and mediates Ca2+ release

AUTOR(ES)

Patterson, Randen L.

FONTE

National Academy of Sciences

RESUMO

RACK1 is not a G protein but closely resembles the heterotrimeric Gβ-subunit. RACK1 serves as a scaffold, linking protein kinase C to its substrates. We demonstrate that RACK1 physiologically binds inositol 1,4,5-trisphosphate receptors and regulates Ca2+ release by enhancing inositol 1,4,5-trisphosphate receptor binding affinity for inositol 1,4,5-trisphosphate. Overexpression of RACK1 or depletion of RACK1 by interference RNA markedly augments or diminishes Ca2+ release, respectively, without affecting Ca2+ entry. These findings establish RACK1 as a physiologic mediator of agonist-induced Ca2+ release.

Documentos Relacionados

• Activating calcium release through inositol 1,4,5-trisphosphate receptors without inositol 1,4,5-trisphosphate
• Diffusion of inositol 1,4,5-trisphosphate but not Ca2+ is necessary for a class of inositol 1,4,5-trisphosphate-induced Ca2+ waves.
• Inositol 1,4,5-trisphosphate receptor/GAPDH complex augments Ca2+ release via locally derived NADH
• Bcl-XL affects Ca2+ homeostasis by altering expression of inositol 1,4,5-trisphosphate receptors
• Agonist-induced Ca2+ entry determined by inositol 1,4,5-trisphosphate recognition