title: SAPAPs. A family of PSD-95/SAP90-associated proteins localized at postsynaptic density.
abstract: PSD-95/SAP90 is a member of membrane-associated guanylate kinases localized at postsynaptic density (PSD) in neuronal cells. Membrane-associated guanylate kinases are a family of signaling molecules expressed at various submembrane domains which have the PDZ (DHR) domains, the SH3 domain, and the guanylate kinase domain. PSD-95/SAP90 interacts with N-methyl-D-aspartate receptors 2A/B, Shaker-type potassium channels, and brain nitric oxide synthase through the PDZ (DHR) domains and clusters these molecules at synaptic junctions. However, neither the function of the SH3 domain or the guanylate kinase domain of PSD-95/SAP90, nor the protein interacting with these domains has been identified. We have isolated here a novel protein family consisting of at least four members which specifically interact with PSD-95/SAP90 and its related proteins through the guanylate kinase domain, and named these proteins SAPAPs (SAP90/PSD-95-Associated Proteins). SAPAPs are specifically expressed in neuronal cells and enriched in the PSD fraction. SAPAPs induce the enrichment of PSD-95/SAP90 to the plasma membrane in transfected cells. Thus, SAPAPs may have a potential activity to maintain the structure of PSD by concentrating its components to the membrane area.
authors.affiliation: Takai Biotimer Project, ERATO, Japan Science and Technology Corporation, c/o JCR Pharmaceuticals Co., Ltd., 2-2-10 Murotani, Nishi-ku, Kobe 651-22, Japan.
authors.forename: M
authors.initials: M
authors.lastname: Takeuchi
authors.forename: Y
authors.initials: Y
authors.lastname: Hata
authors.forename: K
authors.initials: K
authors.lastname: Hirao
authors.forename: A
authors.initials: A
authors.lastname: Toyoda
authors.forename: M
authors.initials: M
authors.lastname: Irie
authors.forename: Y
authors.initials: Y
authors.lastname: Takai
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001665:Binding Sites; D001921:Brain / Q000201:enzymology / Q000378:metabolism*; D019556:COS Cells; D003001:Cloning, Molecular; D018076:DNA, Complementary; D000076122:Disks Large Homolog 4 Protein; D015723:Gene Library; D051528:Guanylate Kinases; D047908:Intracellular Signaling Peptides and Proteins; D007700:Kinetics; D008565:Membrane Proteins; D008969:Molecular Sequence Data; D009419:Nerve Tissue Proteins / Q000737:chemistry* / Q000378:metabolism*; D009474:Neurons / Q000201:enzymology* / Q000648:ultrastructure; D019001:Nitric Oxide Synthase / Q000378:metabolism; D009703:Nucleoside-Phosphate Kinase / Q000378:metabolism; D015221:Potassium Channels / Q000378:metabolism; D051381:Rats; D016194:Receptors, N-Methyl-D-Aspartate / Q000378:metabolism; D011994:Recombinant Proteins / Q000737:chemistry / Q000378:metabolism; D000074407:SAP90-PSD95 Associated Proteins; D017386:Sequence Homology, Amino Acid; D051637:Shaker Superfamily of Potassium Channels; D013569:Synapses / Q000378:metabolism*; D014162:Transfection
chemical_list: D018076:DNA, Complementary; D000076122:Disks Large Homolog 4 Protein; C501449:Dlg4 protein, rat; D047908:Intracellular Signaling Peptides and Proteins; D008565:Membrane Proteins; D009419:Nerve Tissue Proteins; D015221:Potassium Channels; D016194:Receptors, N-Methyl-D-Aspartate; D011994:Recombinant Proteins; D000074407:SAP90-PSD95 Associated Proteins; D051637:Shaker Superfamily of Potassium Channels; C033652:postsynaptic density proteins; D019001:Nitric Oxide Synthase; D009703:Nucleoside-Phosphate Kinase; D051528:Guanylate Kinases