Rapid Redistribution of the Postsynaptic Density Protein PSD-Zip45 (Homer 1c) and Its Differential Regulation by NMDA Receptors and Calcium Channels

Shigeo Okabe, Tomoe Urushido, Daijiro Konno, Haruo Okado, Kenji Sobue
2001 Journal of Neuroscience  
PSD-Zip45 (Homer 1c) and PSD-95 are postsynaptic density (PSD) proteins containing distinct protein-interacting motifs. Green fluorescent protein (GFP)-tagged PSD-Zip45 and PSD-95 molecules were targeted to the PSD in hippocampal neurons. We analyzed dynamic behavior of these GFP-tagged PSD proteins by using time-lapse confocal microscopy. In contrast to the less dynamic properties of PSD-95, PSD-Zip45 showed rapid redistribution and a higher steady-state turnover rate. Differential stimulation
more » ... protocols were found to alter the direction of PSD-Zip45 assembly-disassembly. Transient in-creases in intracellular Ca 2ϩ by voltage-dependent Ca 2ϩ channel activation induced PSD-Zip45 clustering. In contrast, NMDA receptor-dependent Ca 2ϩ influx resulted in the disassembly of PSD-Zip45 clusters. Thus, neuronal activity differentially redistributes a specific subset of PSD proteins, which are important for localization of both surface receptors and intracellular signaling complexes.
doi:10.1523/jneurosci.21-24-09561.2001 pmid:11739567 fatcat:dyoy4uo2bnculk2njllxjrqg6e