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Biomedical subjects

H C Kornau

Publications and source records attributed to H C Kornau.

4 recordsLinked to original sources

Domain interaction between NMDA receptor subunits and the postsynaptic density protein PSD-95.

The N-methyl-D-aspartate (NMDA) receptor subserves synaptic glutamate-induced transmission and plasticity in central neurons. The yeast two-hybrid system was used to show that the cytoplasmic tails of NMDA receptor subunits interact with a prominent postsynaptic density protein PSD-95. The second PDZ domain in PSD-95 binds to the seven-amino acid, COOH-terminal domain containing the terminal tSXV motif (where S is serine, X is any amino acid, and V is valine) common to NR2 subunits and certain NR1 splice forms. Transcripts encoding PSD-95 are expressed in a pattern similar to that of NMDA receptors, and the NR2B subunit co-localizes with PSD-95 in cultured rat hippocampal neurons. The interaction of these proteins may affect the plasticity of excitatory synapses.

Amino Acid Sequence

The organization of the gene for the functionally dominant alpha-amino-3-hydroxy-5-methylisoxazole-4-propionic acid receptor subunit GluR-B.

The murine gene encoding the GluR-B subunit of alpha-amino-3-hydroxy-5-methylisoxazole-4-propionic acid receptors was characterized with respect to exon-intron organization, transcriptional start site, alternatively spliced transcripts, and adenosine to guanosine substitutions between gene and complementary DNA sequence. The GluR-B gene spans > 90 kilobase pairs and harbors 17 exons. Transcription appears to initiate approximately 430 nucleotides upstream of the translational start codon, with no intron in the 5'-untranslated region of the gene. Four alternatively spliced mRNAs are generated from the primary GluR-B transcript, two containing the modules Flip and Flop, and another two with alternate C-terminal coding sequence. The major GluR-B mRNAs in murine brain, 4 and 6 kilobase differ in the length of their 3'-untranslated region.

Alternative Splicing

Mutations in E.coli 16s rRNA that enhance and decrease the activity of a suppressor tRNA.

The in vivo expression of mutations constructed within helix 34 of 16S rRNA has been examined together with a nonsense tRNA suppressor for their action at stop codons. The data revealed two novel results: in contrast to previous findings, some of the rRNA mutations affected suppression at UAA and UAG nonsense codons. Secondly, both an increase and a decrease in the efficiency of the suppressor tRNA were induced by the mutations. This is the first report that rRNA mutations decreased the efficiency of a suppressor tRNA. The data are interpreted as there being competition between the two release factors (RF-1 and RF-2) for an overlapping domain and that helix 34 influences this interaction.

Base Sequence