PICK1 mediates transient synaptic expression of GluA2-lacking AMPA receptors during glycine-induced AMPA receptor trafficking.
The number and subunit composition of postsynaptic AMPA receptors (AMPARs) is a key determinant of synaptic transmission. The vast majority of AMPARs contain GluA2 subunit, which renders the channel impermeable to calcium. However, a small proportion are GluA2 lacking and therefore calcium permeable (CP-AMPARs). It has been proposed recently that long-term potentiation (LTP) involves not only an increase in the total number of AMPARs at the synapse but also a transient switch to CP-AMPARs in the first few minutes after LTP induction. The molecular mechanisms that underlie this switch to CP-AMPARs and the subsequent switch back to calcium-impermeable AMPARs are unknown. Here, we show that endogenous GluA1 is rapidly inserted at the synaptic plasma membrane of rat hippocampal neurons immediately after stimulation with elevated glycine, a treatment known to induce LTP. In contrast, GluA2 is restricted from trafficking to the cell surface by a glycine-induced increase in PICK1-GluA2 binding on endosomal compartments. Between 5 and 20 min after stimulus, activation of CP-AMPARs triggers a release of GluA2 from PICK1, allowing GluA2-containing AMPARs to traffic to the synaptic plasma membrane. These results define a PICK1-dependent mechanism that underlies transient alterations in the subunit composition and calcium permeability of synaptic AMPARs that is important during the early phase after stimulation with glycine and therefore is likely to be important during the expression of LTP.
Medical Research Council Centre for Synaptic Plasticity and School of Biochemistry, Medical Sciences Building, University of Bristol, Bristol, BS8 1TD, United Kingdom.
Nadia
N
Jaafari
Jeremy M
JM
Henley
Jonathan G
JG
Hanley
D000818:Animals; D019921:Biotinylation; D002118:Calcium / Q000378:metabolism; D002352:Carrier Proteins / Q000235:genetics / Q000378:metabolism*; D002478:Cells, Cultured; D003598:Cytoskeletal Proteins; D000076122:Disks Large Homolog 4 Protein; D004622:Embryo, Mammalian; D011992:Endosomes / Q000187:drug effects / Q000378:metabolism; D019204:GTP-Binding Proteins / Q000378:metabolism; D005786:Gene Expression Regulation / Q000187:drug effects / Q000502:physiology; D005998:Glycine / Q000494:pharmacology*; D006624:Hippocampus / Q000166:cytology; D047468:Immunoprecipitation; D047908:Intracellular Signaling Peptides and Proteins / Q000378:metabolism; D017774:Long-Term Potentiation / Q000187:drug effects / Q000235:genetics; D008565:Membrane Proteins / Q000378:metabolism; D018613:Microscopy, Confocal; D009154:Mutation / Q000235:genetics; D009419:Nerve Tissue Proteins / Q000378:metabolism; D009474:Neurons / Q000166:cytology / Q000502:physiology*; D009687:Nuclear Proteins / Q000235:genetics / Q000378:metabolism*; D021381:Protein Transport / Q000187:drug effects; D034741:RNA, Small Interfering / Q000235:genetics / Q000378:metabolism; D051381:Rats; D017208:Rats, Wistar; D018091:Receptors, AMPA / Q000172:deficiency / Q000235:genetics / Q000378:metabolism*; D013096:Spermine / Q000031:analogs & derivatives / Q000494:pharmacology; D013569:Synapses / Q000378:metabolism; D013997:Time Factors; D014162:Transfection; D014168:Transferrin / Q000378:metabolism; D033921:Vesicular Transport Proteins / Q000378:metabolism
D002352:Carrier Proteins; D003598:Cytoskeletal Proteins; D000076122:Disks Large Homolog 4 Protein; C501449:Dlg4 protein, rat; C491308:Grip1 protein, rat; D047908:Intracellular Signaling Peptides and Proteins; D008565:Membrane Proteins; D009419:Nerve Tissue Proteins; D009687:Nuclear Proteins; C498298:PICK1 protein, rat; D034741:RNA, Small Interfering; D018091:Receptors, AMPA; D014168:Transferrin; D033921:Vesicular Transport Proteins; C492252:Wdr44 protein, rat; C093846:early endosome antigen 1; C067506:1-naphthylacetylspermine; D013096:Spermine; D019204:GTP-Binding Proteins; C104722:glutamate receptor ionotropic, AMPA 2; D002118:Calcium; D005998:Glycine