title: Differential expression of isoforms of PSD-95 binding protein (GKAP/SAPAP1) during rat brain development.
abstract: PSD-95/SAP90, which binds to the C-terminus of NMDA receptor and Shaker-type potassium channel, is one of the major postsynaptic density proteins. Recently, novel classes of proteins interacting with the guanylate kinase domain of PSD-95 have been identified, guanylate kinase-associated protein (GKAP) and SAP90/PSD-95-associated proteins (SAPAPs). Here we report the isolation of new isoforms of PSD-95 binding protein (GKAP/SAPAP1) using the yeast two-hybrid system. The isolated protein directly interacts with the guanylate kinase domain of PSD-95. Northern blot analyses revealed that the expression of these isoforms containing distinct N-terminal sequences is differentially regulated during brain development. The present findings suggest that each isoform of the PSD-95 binding protein is differentially expressed in a development-dependent manner and may be involved in the complex formation of PSD-95 and channel/receptors at the postsynaptic density.
authors.affiliation: Department of Neurochemistry and Neuropharmacology, Biomedical Research Center, Osaka University Medical School, Suita, Japan.
authors.forename: N
authors.initials: N
authors.lastname: Kawashima
authors.forename: K
authors.initials: K
authors.lastname: Takamiya
authors.forename: J
authors.initials: J
authors.lastname: Sun
authors.forename: A
authors.initials: A
authors.lastname: Kitabatake
authors.forename: K
authors.initials: K
authors.lastname: Sobue
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001921:Brain / Q000196:embryology / Q000378:metabolism*; D002352:Carrier Proteins / Q000096:biosynthesis* / Q000235:genetics; D000076122:Disks Large Homolog 4 Protein; D005260:Female; D018507:Gene Expression Regulation, Developmental; D047908:Intracellular Signaling Peptides and Proteins; D008565:Membrane Proteins; D008969:Molecular Sequence Data; D009419:Nerve Tissue Proteins / Q000378:metabolism*; D011247:Pregnancy; D051381:Rats; D000074407:SAP90-PSD95 Associated Proteins; D017421:Sequence Analysis
chemical_list: D002352:Carrier Proteins; D000076122:Disks Large Homolog 4 Protein; C501449:Dlg4 protein, rat; D047908:Intracellular Signaling Peptides and Proteins; D008565:Membrane Proteins; D009419:Nerve Tissue Proteins; D000074407:SAP90-PSD95 Associated Proteins; C033652:postsynaptic density proteins