The rat brain postsynaptic density fraction contains a homolog of the Drosophila discs-large tumor suppressor protein.
In CNS synapses, the synaptic junctional complex with associated postsynaptic density is presumed to contain proteins responsible for adhesion between pre- and postsynaptic membranes and for postsynaptic signal transduction. We have found that a prominent, brain-specific protein (PSD-95) enriched in the postsynaptic density fraction from rat brain is highly similar to the Drosophila lethal(1)discs-large-1 (dlg) tumor suppressor protein. The dlg protein is associated with septate junctions in developing flies and contains a guanylate kinase domain that is required for normal control of cell division. The sequence similarity between dlg and PSD-95 suggests that molecular mechanisms critical for growth control in developing organisms may also regulate synapse formation, stabilization, or function in the adult brain.
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Division of Biology, California Institute of Technology, Pasadena 91125.
Hunt
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Kennedy
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D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D001921:Brain / Q000196:embryology / Q000254:growth & development / Q000502:physiology; D001923:Brain Chemistry; D004247:DNA / Q000737:chemistry; D003712:Dendrites / Q000737:chemistry; D000076122:Disks Large Homolog 4 Protein; D029721:Drosophila Proteins; D015870:Gene Expression; D007301:Insect Hormones / Q000737:chemistry*; D047908:Intracellular Signaling Peptides and Proteins; D008565:Membrane Proteins; D008969:Molecular Sequence Data; D009419:Nerve Tissue Proteins / Q000737:chemistry* / Q000235:genetics; D012333:RNA, Messenger / Q000032:analysis; D051381:Rats; D017386:Sequence Homology, Amino Acid; D013569:Synapses / Q000737:chemistry* / Q000502:physiology; D014018:Tissue Distribution; D025521:Tumor Suppressor Proteins
D000076122:Disks Large Homolog 4 Protein; C501449:Dlg4 protein, rat; D029721:Drosophila Proteins; D007301:Insect Hormones; D047908:Intracellular Signaling Peptides and Proteins; D008565:Membrane Proteins; D009419:Nerve Tissue Proteins; D012333:RNA, Messenger; D025521:Tumor Suppressor Proteins; C033652:postsynaptic density proteins; C070350:dlg1 protein, Drosophila; D004247:DNA