title: AIDA-1 Moves out of the Postsynaptic Density Core under Excitatory Conditions.
abstract: AIDA-1 is highly enriched in postsynaptic density (PSD) fractions and is considered a major component of the PSD complex. In the present study, immunogold electron microscopy was applied to determine localization as well as the activity-induced redistribution of AIDA-1 at the PSD using two antibodies that recognize two different epitopes. In cultured rat hippocampal neurons under basal conditions, immunogold label for AIDA-1 is mostly located within the dense core of the PSD, with a median distance of ~30 nm from the postsynaptic membrane. Under excitatory conditions, such as depolarization with high K+ (90 mM, 2 min) or application of NMDA (50 μM, 2 min), AIDA-1 label density at the PSD core is reduced to 40% of controls and the median distance of label from the postsynaptic membrane increases to ~55 nm. The effect of excitatory conditions on the postsynaptic distribution of AIDA-1 is reversed within 30 minutes after returning to control conditions. The reversible removal of AIDA-1 from the PSD core under excitatory conditions is similar to the redistribution of another abundant PSD protein, SynGAP. Both SynGAP-alpha1 and AIDA-1 are known to bind PSD-95. Activity-induced transient translocation of these abundant proteins from the PSD core could promote structural flexibility, vacate sites on PSD-95 for the insertion of other components and thus may create a window for synaptic modification.
authors.affiliation: Laboratory of Neurobiology, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, Maryland, United States of America.
authors.forename: Ayse
authors.initials: A
authors.lastname: Dosemeci
authors.affiliation: Laboratory of Neurobiology, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, Maryland, United States of America.
authors.forename: Dana
authors.initials: D
authors.lastname: Toy
authors.affiliation: Laboratory of Neurobiology, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, Maryland, United States of America.
authors.forename: Thomas S
authors.initials: TS
authors.lastname: Reese
authors.affiliation: EM Facility, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, Maryland, United States of America.
authors.forename: Jung-Hwa
authors.initials: JH
authors.lastname: Tao-Cheng
mesh_terms: D000818:Animals; D002352:Carrier Proteins / Q000378:metabolism*; D002478:Cells, Cultured; D006624:Hippocampus / Q000166:cytology; D016202:N-Methylaspartate / Q000494:pharmacology*; D009474:Neurons / Q000166:cytology / Q000378:metabolism / Q000648:ultrastructure; D057907:Post-Synaptic Density / Q000187:drug effects / Q000378:metabolism* / Q000648:ultrastructure; D011188:Potassium / Q000494:pharmacology*; D017207:Rats, Sprague-Dawley
chemical_list: C000607858:Anks1b protein, rat; D002352:Carrier Proteins; D016202:N-Methylaspartate; D011188:Potassium