AKAP79 enables calcineurin to directly suppress protein kinase A activity

Autor: Timothy W Church, Parul Tewatia, Saad Hannan, João Antunes, Olivia Eriksson, Trevor G Smart, Jeanette Hellgren Kotaleski, Matthew G Gold
Jazyk: angličtina
Rok vydání: 2021
Předmět:
Zdroj: eLife, Vol 10 (2021)
Druh dokumentu: article
ISSN: 2050-084X
DOI: 10.7554/eLife.68164
Popis: Interplay between the second messengers cAMP and Ca2+ is a hallmark of dynamic cellular processes. A common motif is the opposition of the Ca2+-sensitive phosphatase calcineurin and the major cAMP receptor, protein kinase A (PKA). Calcineurin dephosphorylates sites primed by PKA to bring about changes including synaptic long-term depression (LTD). AKAP79 supports signaling of this type by anchoring PKA and calcineurin in tandem. In this study, we discovered that AKAP79 increases the rate of calcineurin dephosphorylation of type II PKA regulatory subunits by an order of magnitude. Fluorescent PKA activity reporter assays, supported by kinetic modeling, show how AKAP79-enhanced calcineurin activity enables suppression of PKA without altering cAMP levels by increasing PKA catalytic subunit capture rate. Experiments with hippocampal neurons indicate that this mechanism contributes toward LTD. This non-canonical mode of PKA regulation may underlie many other cellular processes.
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