title: Rapid dispersion of SynGAP from synaptic spines triggers AMPA receptor insertion and spine enlargement during LTP.
abstract: SynGAP is a Ras-GTPase activating protein highly enriched at excitatory synapses in the brain. Previous studies have shown that CaMKII and the RAS-ERK pathway are critical for several forms of synaptic plasticity including LTP. NMDA receptor-dependent calcium influx has been shown to regulate the RAS-ERK pathway and downstream events that result in AMPA receptor synaptic accumulation, spine enlargement, and synaptic strengthening during LTP. However, the cellular mechanisms whereby calcium influx and CaMKII control Ras activity remain elusive. Using live-imaging techniques, we have found that SynGAP is rapidly dispersed from spines upon LTP induction in hippocampal neurons, and this dispersion depends on phosphorylation of SynGAP by CaMKII. Moreover, the degree of acute dispersion predicts the maintenance of spine enlargement. Thus, the synaptic dispersion of SynGAP by CaMKII phosphorylation during LTP represents a key signaling component that transduces CaMKII activity to small G protein-mediated spine enlargement, AMPA receptor synaptic incorporation, and synaptic potentiation.
authors.affiliation: Department of Neuroscience and Howard Hughes Medical Institute, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA.
authors.forename: Yoichi
authors.initials: Y
authors.lastname: Araki
authors.affiliation: Division of Life Science, Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong.
authors.forename: Menglong
authors.initials: M
authors.lastname: Zeng
authors.affiliation: Division of Life Science, Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong.
authors.forename: Mingjie
authors.initials: M
authors.lastname: Zhang
authors.affiliation: Department of Neuroscience and Howard Hughes Medical Institute, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA. Electronic address: rhuganir@jhmi.edu.
authors.forename: Richard L
authors.initials: RL
authors.lastname: Huganir
mesh_terms: D000818:Animals; D002118:Calcium / Q000378:metabolism; D054732:Calcium-Calmodulin-Dependent Protein Kinase Type 2 / Q000378:metabolism*; D049229:Dendritic Spines / Q000378:metabolism* / Q000502:physiology; D020690:GTPase-Activating Proteins / Q000378:metabolism*; D006624:Hippocampus / Q000166:cytology* / Q000378:metabolism; D017774:Long-Term Potentiation / Q000502:physiology*; D036881:Long-Term Synaptic Depression; D020935:MAP Kinase Signaling System; D009473:Neuronal Plasticity; D009474:Neurons / Q000378:metabolism / Q000502:physiology; D010766:Phosphorylation; D051381:Rats; D018091:Receptors, AMPA / Q000378:metabolism*; D016194:Receptors, N-Methyl-D-Aspartate / Q000378:metabolism*; D015398:Signal Transduction; D018631:ras Proteins
chemical_list: D020690:GTPase-Activating Proteins; D018091:Receptors, AMPA; D016194:Receptors, N-Methyl-D-Aspartate; C112202:Syngap1 protein, rat; D054732:Calcium-Calmodulin-Dependent Protein Kinase Type 2; D018631:ras Proteins; D002118:Calcium