An ultrasensitive Ca2+/calmodulin-dependent protein kinase II-protein phosphatase 1 switch facilitates specificity in postsynaptic calcium signaling. Academic Article uri icon

Overview

abstract

  • The strength of hippocampal synapses can be persistently increased by signals that activate Ca2+/calmodulin-dependent protein kinase II (CaMKII). This CaMKII-dependent long-term potentiation is important for hippocampal learning and memory. In this work we show that CaMKII exhibits an intriguing switch-like activation that likely is important for changes in synaptic strength. We found that autophosphorylation of CaMKII by itself showed a steep dependence on Ca2+ concentration [Hill coefficient (nH) approximately 5]. However, an even steeper Ca2+ dependence (nH approximately 8) was observed when autophosphorylation is balanced by the dephosphorylation activity of protein phosphatase 1 (PP1). This autophosphorylation-dephosphorylation switch was found to be reversible because PP1 dephosphorylates CaMKII when Ca2+ is lowered to a basal level. The switch-like response of a CaMKII-PP1 system suggests that CaMKII and PP1 may function together as a simple molecular device that specifically translates only strong Ca2+ signals into all-or-none potentiation of individual hippocampal synapses.

publication date

  • August 19, 2003

Research

keywords

  • Calcium Signaling
  • Calcium-Calmodulin-Dependent Protein Kinases
  • Phosphoprotein Phosphatases
  • Synapses

Identity

PubMed Central ID

  • PMC193592

Scopus Document Identifier

  • 0041836230

PubMed ID

  • 12928489

Additional Document Info

volume

  • 100

issue

  • 18