Publications

• Comparison of solubilised kainate and alpha-amino-3-hydroxy-5- methylisoxazolepropionate binding sites in chick cerebellum.

  Henley J.M., Barnard E.A.

  [3H]Kainate bound to chick cerebellar membranes with a KD of 0.6 microM and with an exceptionally high Bmax of 165 pmol/mg of protein. In octylglucoside-solubilised extracts, the affinity of [3H]kainate was reduced (KD = 2.7 microM), but the Bmax was relatively unchanged (130 pmol/mg of protein). ... >> More

  [3H]Kainate bound to chick cerebellar membranes with a KD of 0.6 microM and with an exceptionally high Bmax of 165 pmol/mg of protein. In octylglucoside-solubilised extracts, the affinity of [3H]kainate was reduced (KD = 2.7 microM), but the Bmax was relatively unchanged (130 pmol/mg of protein). The rank potency of competitive ligands was domoate greater than kainate greater than 6-cyano-7-nitroquinoxaline-2,3-dione (CNQX) greater than glutamate. Binding sites for alpha-[3H]amino-3-hydroxy-5-methylisoxazolepropionate ([3H]AMPA) were much less abundant, with KD and Bmax values in membranes of 86 nM and 1 pmol/mg of protein, respectively. The affinity of [3H]AMPA binding was also reduced on solubilisation (KD = 465 nM), but there was an increase in the Bmax (1.7 pmol/mg of protein). Quisqualate and CNQX were the most effective displacers of [3H]AMPA binding, but kainate was also a relatively potent inhibitor. However, in contrast to the displacement profile for [3H]kainate, domoate was markedly less potent than kainate at displacing [3H]AMPA. These results suggest that [3H]AMPA binds to a small subset of the kainate sites that, unlike the majority of the [3H]kainate binding protein, which has been reported to be located in the Bergmann glia, may represent neuronal unitary non-N-methyl-D-aspartate receptors. << Less

  J Neurochem 56:702-705(1991) [PubMed] [EuropePMC]

• Cloning and functional expression of a human Na(+) and Cl(-)-dependent neutral and cationic amino acid transporter B(0+).

  Sloan J.L., Mager S.

  A Na(+)-dependent neutral and cationic amino acid transport system (B(0+)) plays an important role in many cells and tissues; however, the molecular basis for this transport system is still unknown. To identify new transporters, the expressed sequence tag database was queried, and cDNA fragments w ... >> More

  A Na(+)-dependent neutral and cationic amino acid transport system (B(0+)) plays an important role in many cells and tissues; however, the molecular basis for this transport system is still unknown. To identify new transporters, the expressed sequence tag database was queried, and cDNA fragments with sequence similarity to the Na(+)/Cl(-)-dependent neurotransmitter transporter family were identified. Based on these sequences, rapid amplification of cDNA ends of human mammary gland cDNA was used to obtain a cDNA of 4.5 kilobases (kb). The open reading frame encodes a 642-amino acid protein named amino acid transporter B(0+). Human ATB(0+) (hATB(0+)) is a novel member of the Na(+)/Cl(-)-dependent neurotransmitter transporter family with the highest sequence similarity to the glycine and proline transporters. Northern blot analysis identified transcripts of approximately 4.5 kb and approximately 2 kb in the lung. Another tissue survey suggests expression in the trachea, salivary gland, mammary gland, stomach, and pituitary gland. Electrophysiology and radiolabeled amino acid uptake measurements were used to functionally characterize the transporter expressed in Xenopus oocytes. hATB(0+) was found to transport both neutral and cationic amino acids, with the highest affinity for hydrophobic amino acids and the lowest affinity for proline. Amino acid transport was Na(+) and Cl(-)-dependent and was attenuated in the presence of 2-aminobicyclo-[2.2.1]-heptane-2-carboxylic acid, a system B(0+) inhibitor. These characteristics are consistent with system B(0+) amino acid transport. Thus, hATB(0+) is the first cloned B(0+) amino acid transporter. << Less

  J. Biol. Chem. 274:23740-23745(1999) [PubMed] [EuropePMC]

  This publication is cited by 16 other entries.