title: The palmitoyl acyltransferase DHHC2 regulates recycling endosome exocytosis and synaptic potentiation through palmitoylation of AKAP79/150.
abstract: Phosphorylation and dephosphorylation of AMPA-type ionotropic glutamate receptors (AMPARs) by kinases and phosphatases and interactions with scaffold proteins play essential roles in regulating channel biophysical properties and trafficking events that control synaptic strength during NMDA receptor-dependent synaptic plasticity, such as LTP and LTD. We previously demonstrated that palmitoylation of the AMPAR-linked scaffold protein A-kinase anchoring protein (AKAP) 79/150 is required for its targeting to recycling endosomes in dendrites, where it regulates exocytosis from these compartments that is required for LTP-stimulated enlargement of postsynaptic dendritic spines, delivery of AMPARs to the plasma membrane, and maintenance of synaptic potentiation. Here, we report that the recycling endosome-resident palmitoyl acyltransferase DHHC2 interacts with and palmitoylates AKAP79/150 to regulate these plasticity signaling mechanisms. In particular, RNAi-mediated knockdown of DHHC2 expression in rat hippocampal neurons disrupted stimulation of exocytosis from recycling endosomes, enlargement of dendritic spines, AKAP recruitment to spines, and potentiation of AMPAR-mediated synaptic currents that occur during LTP. Importantly, expression of a palmitoylation-independent lipidated AKAP mutant in DHHC2-deficient neurons largely restored normal plasticity regulation. Thus, we conclude that DHHC2-AKAP79/150 signaling is an essential regulator of dendritic recycling endosome exocytosis that controls both structural and functional plasticity at excitatory synapses.
authors.affiliation: Department of Pharmacology and.
authors.forename: Kevin M
authors.initials: KM
authors.lastname: Woolfrey
authors.affiliation: Department of Pharmacology and.
authors.forename: Jennifer L
authors.initials: JL
authors.lastname: Sanderson
authors.affiliation: Department of Pharmacology and Program in Neuroscience University of Colorado School of Medicine, Anschutz Medical Campus, Aurora, Colorado 80045 mark.dellacqua@ucdenver.edu.
authors.forename: Mark L
authors.initials: ML
authors.lastname: Dell'Acqua
mesh_terms: D054758:A Kinase Anchor Proteins / Q000378:metabolism*; D000217:Acyltransferases / Q000235:genetics / Q000378:metabolism*; D000818:Animals; D019556:COS Cells; D002478:Cells, Cultured; D002522:Chlorocebus aethiops; D049229:Dendritic Spines / Q000378:metabolism; D011992:Endosomes / Q000378:metabolism*; D005089:Exocytosis; D005260:Female; D057809:HEK293 Cells; D006624:Hippocampus / Q000166:cytology / Q000378:metabolism; D006801:Humans; D054878:Lipoylation; D017774:Long-Term Potentiation; D008297:Male; D051381:Rats; D017207:Rats, Sprague-Dawley; D013569:Synapses / Q000378:metabolism / Q000502:physiology
chemical_list: D054758:A Kinase Anchor Proteins; D000217:Acyltransferases; C000596549:Zdhhc2 protein, rat
keywords: A-kinase anchoring protein; AMPAR; LTP; palmitoylation; recycling endosome; trafficking