title: Synaptic and subcellular localization of A-kinase anchoring protein 150 in rat hippocampal CA1 pyramidal cells: Co-localization with excitatory synaptic markers.
abstract: Excitatory and inhibitory ionotropic receptors are regulated by protein kinases and phosphatases, which are localized to specific subcellular locations by one of several anchoring proteins. One of these is the A-kinase anchoring protein (AKAP150), which confers spatial specificity to protein kinase A and protein phosphatase 2B in the rat brain. The distribution of AKAP150 was examined at rat hippocampal CA1 pyramidal cell asymmetric and symmetric post-synaptic densities and with respect to the distribution of markers of excitatory (vesicular glutamate transporter 1, glutamate receptor subunit 1) and inhibitory receptors (vesicular GABA transporter, GABA receptor type A beta2/3 subunits, gephyrin) and the Golgi marker, trans-Golgi network glycoprotein 38. AKAP150 was close to asymmetric synapses, consistent with numerous molecular and biochemical studies suggesting its interaction with components of the excitatory postsynaptic density. In contrast, we did not find AKAP150-immunoreactivity associated with inhibitory synapses in rat CA1 neurons, despite reports demonstrating an in vitro interaction between AKAP150 and GABA receptor type A receptor beta subunits, and the reported co-localization of these proteins in rat hippocampal cultures. There was some overlap between AKAP150 and GABA receptor type A receptor beta2/3-immunoreactivity intracellularly in perinuclear clusters. These findings support previous work indicating the integration of kinase and phosphatase activity at excitatory synapses by AKAP150, but do not support a role for selective targeting of AKAP150 and its accompanying proteins to inhibitory synapses.
authors.affiliation: Department of Pharmacology and the Cellular and Molecular Neurobiology Program, 3035 Arlington Avenue, Medical University of Ohio, Toledo, OH 43614, USA.
authors.forename: S M
authors.initials: SM
authors.lastname: Lilly
authors.forename: F J
authors.initials: FJ
authors.lastname: Alvarez
authors.forename: E I
authors.initials: EI
authors.lastname: Tietz
mesh_terms: D054758:A Kinase Anchor Proteins; D048868:Adaptor Proteins, Signal Transducing / Q000378:metabolism*; D000818:Animals; D002352:Carrier Proteins / Q000378:metabolism; D006624:Hippocampus / Q000166:cytology*; D007150:Immunohistochemistry / Q000379:methods; D008297:Male; D008562:Membrane Glycoproteins / Q000378:metabolism; D008565:Membrane Proteins / Q000378:metabolism; D016253:Microscopy, Immunoelectron / Q000379:methods; D017966:Pyramidal Cells / Q000166:cytology / Q000378:metabolism*; D051381:Rats; D017207:Rats, Sprague-Dawley; D018091:Receptors, AMPA / Q000378:metabolism; D011963:Receptors, GABA-A / Q000378:metabolism; D013347:Subcellular Fractions / Q000378:metabolism; D013569:Synapses / Q000378:metabolism* / Q000648:ultrastructure; D050598:Vesicular Glutamate Transport Protein 1 / Q000378:metabolism*; D050495:Vesicular Inhibitory Amino Acid Transport Proteins / Q000378:metabolism
chemical_list: D054758:A Kinase Anchor Proteins; D048868:Adaptor Proteins, Signal Transducing; D002352:Carrier Proteins; D008562:Membrane Glycoproteins; D008565:Membrane Proteins; D018091:Receptors, AMPA; D011963:Receptors, GABA-A; D050598:Vesicular Glutamate Transport Protein 1; D050495:Vesicular Inhibitory Amino Acid Transport Proteins; C415703:Akap5 protein, rat; C493466:Slc17a7 protein, rat; C118623:Slc32a1 protein, rat; C513045:Tgoln2 protein, rat; C073441:gephyrin