Journal Article

Neurogranin regulates CaM dynamics at dendritic spines

Petersen, Amber, Gerges, Nashaat Z.

2015

Overview

Calmodulin (CaM) plays a key role in synaptic function and plasticity due to its ability to mediate Ca 2+ signaling. Therefore, it is essential to understand the dynamics of CaM at dendritic spines. In this study we have explored CaM dynamics using live-cell confocal microscopy and fluorescence recovery after photobleaching (FRAP) to study CaM diffusion. We find that only a small fraction of CaM in dendritic spines is immobile. Furthermore, the diffusion rate of CaM was regulated by neurogranin (Ng), a CaM-binding protein enriched at dendritic spines. Interestingly, Ng did not influence the immobile fraction of CaM at recovery plateau. We have previously shown that Ng enhances synaptic strength in a CaM-dependent manner. Taken together, these data indicate that Ng-mediated enhancement of synaptic strength is due to its ability to target, rather than sequester, CaM within dendritic spines.

• Publisher: Nature Publishing Group UK,Nature Publishing Group
• Subject: 14/19 / 14/35 / 38/109 / 631/378/2591 / 631/378/340 / Animals / Calcium Signaling / Calcium signalling / Calcium-binding protein / Calmodulin / Calmodulin - genetics / Calmodulin - metabolism / Confocal microscopy / Dendritic spines / Dendritic Spines - metabolism / Experiments / Fibroblasts / Fluorescence recovery after photobleaching / Gene Expression / Hippocampus - metabolism / Humanities and Social Sciences / Kinases / Laboratory animals / Microscopy / Microscopy, Confocal / multidisciplinary / Neurogranin / Neurogranin - genetics / Neurogranin - metabolism / Neurosciences / Phosphorylation / Photobleaching / Protein Binding / Proteins / Rats / Science / Software / Synapses - metabolism / Synaptic plasticity / Synaptic strength