A spatial model of autophosphorylation of CaMKII in a glutamatergic spine suggests a network-driven kinetic mechanism for bistable changes in synaptic strength

Abstract Activation of N-methyl-D-aspartate-type glutamate receptors (NMDARs) at synapses in the CNS triggers changes in synaptic strength that underlie memory formation in response to strong synaptic stimuli. The primary target of Ca2+flowing through NMDARs is Ca2+/calmodulin-dependent protein kinase II (CaMKII) which forms dodecameric holoenzymes that are highly concentrated at the postsynaptic site. Activation of CaMKII is necessary to trigger long-term potentiation of synaptic strength (LTP), and is prolonged by autophosphorylation of subunits within the holoenzyme. Here we use MCell4, an agent-based, stochastic, modeling platform to model CaMKII holoenzymes placed within a realistic spine geometry. We show how two mechanisms of regulation of CaMKII, ‘Ca2+-calmodulin-trapping (CaM-trapping)’ and dephosphorylation by protein phosphatase-1 (PP1) shape the autophosphorylation response during a repeated high-frequency stimulus. Our simulation results suggest that autophosphorylation of CaMKII does not constitute a bistable switch. Instead, prolonged but temporary, autophosphorylation of CaMKII may contribute to a biochemical-network-based ‘kinetic proof-reading” mechanism that controls induction of synaptic plasticity..

Medienart:

Preprint

Erscheinungsjahr:

2024

Erschienen:

2024

Enthalten in:

bioRxiv.org - (2024) vom: 06. Feb. Zur Gesamtaufnahme - year:2024

Sprache:

Englisch

Beteiligte Personen:

Bartol, Thomas M. [VerfasserIn]
Ordyan, Mariam [VerfasserIn]
Sejnowski, Terrence J. [VerfasserIn]
Rangamani, Padmini [VerfasserIn]
Kennedy, Mary B. [VerfasserIn]

Links:

Volltext [kostenfrei]

Themen:

570
Biology

doi:

10.1101/2024.02.02.578696

funding:

Förderinstitution / Projekttitel:

PPN (Katalog-ID):

XBI042378133