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Quantitative proteomics analysis of CaMKII phosphorylation and the CaMKII interactome in the mouse forebrain.

ABSTRACT: Ca(2+)/calmodulin-dependent protein kinase II? (CaMKII?) autophosphorylation at Thr286 and Thr305/Thr306 regulates kinase activity and modulates subcellular targeting and is critical for normal synaptic plasticity and learning and memory. Here, a mass spectrometry-based approach was used to identify Ca(2+)-dependent and -independent in vitro autophosphorylation sites in recombinant CaMKII? and CaMKII?. CaMKII holoenzymes were then immunoprecipitated from subcellular fractions of forebrains isolated from either wild-type (WT) mice or mice with a Thr286 to Ala knock-in mutation of CaMKII? (T286A-KI mice) and analyzed using the same approach in order to characterize in vivo phosphorylation sites in both CaMKII isoforms and identify CaMKII-associated proteins (CaMKAPs). A total of six and seven autophosphorylation sites in CaMKII? and CaMKII?, respectively, were detected in WT mice. Thr286-phosphorylated CaMKII? and Thr287-phosphorylated CaMKII? were selectively enriched in WT Triton-insoluble (synaptic) fractions compared to Triton-soluble (membrane) and cytosolic fractions. In contrast, Thr306-phosphorylated CaMKII? and Ser315- and Thr320/Thr321-phosphorylated CaMKII? were selectively enriched in WT cytosolic fractions. The T286A-KI mutation significantly reduced levels of phosphorylation of CaMKII? at Ser275 across all subcellular fractions and of cytosolic CaMKII? at Ser315 and Thr320/Thr321. Significantly more CaMKAPs coprecipitated with WT CaMKII holoenzymes in the synaptic fraction compared to that in the membrane fraction, with functions including scaffolding, microtubule organization, actin organization, ribosomal function, vesicle trafficking, and others. The T286A-KI mutation altered the interactions of multiple CaMKAPs with CaMKII, including several proteins linked to autism spectrum disorders. These data identify CaMKII isoform phosphorylation sites and a network of synaptic protein interactions that are sensitive to the abrogation of Thr286 autophosphorylation of CaMKII?, likely contributing to the diverse synaptic and behavioral deficits of T286A-KI mice.

SUBMITTER: Baucum AJ

PROVIDER: S-EPMC4609176 | biostudies-literature | 2015 Apr

REPOSITORIES: biostudies-literature

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Quantitative proteomics analysis of CaMKII phosphorylation and the CaMKII interactome in the mouse forebrain.

Baucum Anthony J AJ Shonesy Brian C BC Rose Kristie L KL Colbran Roger J RJ

ACS chemical neuroscience 20150224 4

Ca(2+)/calmodulin-dependent protein kinase IIα (CaMKIIα) autophosphorylation at Thr286 and Thr305/Thr306 regulates kinase activity and modulates subcellular targeting and is critical for normal synaptic plasticity and learning and memory. Here, a mass spectrometry-based approach was used to identify Ca(2+)-dependent and -independent in vitro autophosphorylation sites in recombinant CaMKIIα and CaMKIIβ. CaMKII holoenzymes were then immunoprecipitated from subcellular fractions of forebrains isola ...[more]

PMID: 25650780

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Dataset Information

Quantitative proteomics analysis of CaMKII phosphorylation and the CaMKII interactome in the mouse forebrain.

Publications

Quantitative proteomics analysis of CaMKII phosphorylation and the CaMKII interactome in the mouse forebrain.

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