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Updated: Jun 10, 2026
Preparation of Synaptic Plasma Membrane and Postsynaptic Density Proteins Using a Discontinuous Sucrose Gradient
Published on: September 3, 2014
A plasma membrane Ca2+ ATPase isoform at the postsynaptic density
A C Burette1, E E Strehler, R J Weinberg
1Department of Cell and Developmental Biology, University of North Carolina at Chapel Hill, 314 Taylor Hall, CB# 7090, Chapel Hill, NC 27599, USA. alain_burette@med.unc.edu
Abstract:
Most excitatory input in the hippocampus impinges on dendritic spines. Entry of Ca(2+) into spines through NMDA receptors can trigger a sequence of biochemical reactions leading to sustained changes in synaptic efficacy. To provide specificity, dendritic spines restrict the diffusion of Ca(2+) signaling and downstream molecules. The postsynaptic density (PSD) (the most prominent subdomain within the spine) is the site of Ca(2+) entry through NMDA receptors. We here demonstrate that Ca(2+) can also be removed via pumps embedded in the PSD. Using light- and electron-microscopic immunohistochemistry, we find that PMCA2w, a member of the plasma membrane Ca(2+)-ATPase (PMCA) family, concentrates at the PSD of most hippocampal spines. We propose that PMCA2w may be recruited into supramolecular complexes at the postsynaptic density, thus helping to regulate Ca(2+) nanodomains at subsynaptic sites. Taken together, these results suggest a novel function for PMCAs as modulators of Ca(2+) signaling at the synapse.
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