title: Differential localization of SAP102 and PSD-95 is revealed in hippocampal spines using super-resolution light microscopy.
abstract: Synapse-associated protein 102 (SAP102) and postsynaptic density 95 (PSD-95) are two major cytoskeleton proteins in the postsynaptic density (PSD). Both of them belong to the membrane-associated guanylate kinase (MAGUK) family, which clusters and anchors glutamate receptors and other proteins at synapses. In our previous study, we found that SAP102 and PSD-95 have different distributions, using combined light/electron microscopy (LM/EM) methods.1 Here, we double labeled endogenous SAP102 and PSD-95 in mature hippocampal neurons, and then took images by two different kinds of super resolution microscopy-Stimulated Emission Depletion microscopy (STED) and DeltaVision OMX 3D super resolution microscopy. We found that our 2D and 3D super resolution data were consistent with our previous LM/EM data, showing significant differences in the localization of SAP102 and PSD-95 in spines: SAP102 is distributed in both the PSD and cytoplasm of spines, while PSD-95 is concentrated only in the PSD area. These results indicate functional differences between SAP102 and PSD-95 in synaptic organization and plasticity.
authors.affiliation: Laboratory of Cell Structure and Dynamics Bethesda, MD USA.
authors.forename: Chan-Ying
authors.initials: CY
authors.lastname: Zheng
authors.forename: Ya-Xia
authors.initials: YX
authors.lastname: Wang
authors.forename: Bechara
authors.initials: B
authors.lastname: Kachar
authors.forename: Ronald S
authors.initials: RS
authors.lastname: Petralia