scholarly journals Cysteine residues in the C-terminus of the neutral- and basic-amino-acid transporter heavy-chain subunit contribute to functional properties of the system b0,+-type amino acid transporter

2000 ◽  
Vol 351 (3) ◽  
pp. 677-682 ◽  
Author(s):  
George J. PETER ◽  
Tatiana B. PANOVA ◽  
Graham R. CHRISTIE ◽  
Peter M. TAYLOR
Keyword(s):  
Amino Acid ◽  
Basic Amino Acid ◽  
Thiol Group ◽  
Amino Acid Transporter ◽  
Cysteine Residues ◽  
Type I ◽  
Direct Role ◽  
C Terminus ◽  
Acid Transporter ◽  
Major Target

The neutral- and basic-amino-acid-transport glycoprotein NBAT (rBAT, D2) expressed in renal and jejunal brush-border membranes interacts with the b0,+AT permease to produce a heteromeric transporter effecting amino acid and cystine absorption. NBAT mutations result in type I cystinuria. The b0,+AT permease is presumed to be the catalytic subunit, but we have been investigating the possibility that cysteine residues within the C-terminus of NBAT are also important for expression of transport function. NBAT mutants were produced with combinations of Cys664/671/683 → Ala substitutions. Mutants with Cys664 → Ala show decreased arginine and cystine transport and specifically lose sensitivity to inhibition of transport by the thiol-group reagent N-ethylmaleimide (NEM). We suggest that the C-terminus of NBAT may have a direct role in the mechanism of System b0,+ transport (the major transport activity defective in type I cystinuria) and that Cys664 of NBAT is the major target for NEM-induced inactivation of the transport mechanism.

scholarly journals Primary- and secondary-structural analysis of a unique prokaryotic metallothionein from a Synechococcus sp. cyanobacterium

1988 ◽  
Vol 251 (3) ◽  
pp. 691-699 ◽  
Author(s):  
R W Olafson ◽  
W D McCubbin ◽  
C M Kay
Keyword(s):  
Amino Acid ◽  
Metal Binding ◽  
Helical Structure ◽  
Basic Amino Acid ◽  
Cysteine Residues ◽  
Amino Acid Residues ◽  
C Terminus ◽  
Empirical Relations ◽  
Heavy Metal Binding ◽  
Synechococcus Sp

Biochemical and physiological studies of Synechococcus cyanobacteria have indicated the presence of a low-Mr heavy-metal-binding protein with marked similarity to eukaryotic metallothioneins (MTs). We report here the characterization of a Synechococcus prokaryotic MT isolated by gel-permeation and reverse-phase chromatography. The large number of variants of this molecule found during chromatographic separation could not be attributed to the presence of major isoproteins as assessed by amino acid analysis and amino acid sequencing of isoforms. Two of the latter were shown to have identical primary structures that differed substantially from the well-described eukaryotic MTs. In addition to six long-chain aliphatic residues, two aromatic residues were found adjacent to one another near the centre of the molecule, making this the most hydrophobic MT to be described. Other unusual features included a pair of histidine residues located in repeating Gly-His-Thr-Gly sequences near the C-terminus and a complete lack of association of hydroxylated residues with cysteine residues, as is commonly found in eukaryotes. Similarly, aside from a single lysine residue, no basic amino acid residues were found adjacent to cysteine residues in the sequence. Most importantly, sequence alignment analyses with mammalian, invertebrate and fungal MT sequences showed no statistically significant homology aside from the presence of Cys-Xaa-Cys structures common to all MTs. On the other hand, like other MTs, the prokaryotic molecule appears to be free of alpha-helical structure but has a considerable amount of beta-structure, as predicted by both c.d. measurements and the Chou & Fasman empirical relations. Considered together, these data suggested that some similarity between the metal-thiolate clusters of the prokaryote and eukaryote MTs may exist.

scholarly journals Multiple components of arginine and phenylalanine transport induced in neutral and basic amino acid transporter-cRNA-injected Xenopus oocytes

1996 ◽  
Vol 318 (3) ◽  
pp. 915-922 ◽  
Author(s):  
George J PETER ◽  
Iain G. DAVIDSON ◽  
Aamir AHMED ◽  
Lynn McILROY ◽  
Alexander R. FORRESTER ◽  
...  
Keyword(s):  
Amino Acid ◽  
Xenopus Oocytes ◽  
Competitive Inhibition ◽  
Protein Complexes ◽  
Basic Amino Acid ◽  
Amino Acid Transporter ◽  
Transport Processes ◽  
Arginine Transport ◽  
Acid Transporter ◽  
Phenylalanine Transport

The induced uptakes of l-[3H]phenylalanine and l-[3H]arginine in oocytes injected with clonal NBAT (neutral and basic amino acid transporter) cRNA show differential inactivation by pre-treatment with N-ethylmaleimide (NEM), revealing at least two distinct transport processes. NEM-resistant arginine transport is inhibited by leucine and phenylalanine but not by alanine or valine; mutual competitive inhibition of NEM-resistant uptake of arginine and phenylalanine indicates that the two amino acids share a single transporter. NEM-senstive arginine transport is inhibited by leucine, phenylalanine, alanine and valine. At least two NEM-sensitive transporters may be expressed because we have been unable to confirm mutual competitive inhibition between arginine and phenylalanine transport. The NEM-resistant transport mechanism appears to involve distinct but overlapping binding sites for cationic and zwitterionic substrates. NBAT is known to form oligomeric protein complexes in cell membranes, and its functional roles when expressed in Xenopus oocytes may include interaction with oocyte proteins, leading to increased native amino acid transport activities; these resemble NBAT-expressed activities in terms of NEM-sensitivity and apparent substrate range (including an unusual inhibition by β-phenylalanine).

scholarly journals Characterization of the rat neutral and basic amino acid transporter utilizing anti-peptide antibodies.

1993 ◽  
Vol 90 (9) ◽  
pp. 4022-4026 ◽  
Author(s):  
R. Mosckovitz ◽  
N. Yan ◽  
E. Heimer ◽  
A. Felix ◽  
S. S. Tate ◽  
...  
Keyword(s):  
Amino Acid ◽  
Basic Amino Acid ◽  
Amino Acid Transporter ◽  
Acid Transporter ◽  
Peptide Antibodies

Cell-surface receptor for ecotropic murine retroviruses is a basic amino-acid transporter

Nature ◽  
1991 ◽  
Vol 352 (6337) ◽  
pp. 729-731 ◽  
Author(s):  
Hao Wang ◽  
Michael P. Kavanaugh ◽  
R. Alan North ◽  
David Kabat
Keyword(s):  
Amino Acid ◽  
Cell Surface ◽  
Basic Amino Acid ◽  
Amino Acid Transporter ◽  
Cell Surface Receptor ◽  
Surface Receptor ◽  
Acid Transporter

scholarly journals Ultrastructural localization of a neutral and basic amino acid transporter in rat kidney and intestine.

1993 ◽  
Vol 90 (16) ◽  
pp. 7779-7783 ◽  
Author(s):  
V. M. Pickel ◽  
M. J. Nirenberg ◽  
J. Chan ◽  
R. Mosckovitz ◽  
S. Udenfriend ◽  
...  
Keyword(s):  
Amino Acid ◽  
Rat Kidney ◽  
Basic Amino Acid ◽  
Ultrastructural Localization ◽  
Amino Acid Transporter ◽  
Acid Transporter

scholarly journals Luminal Heterodimeric Amino Acid Transporter Defective in Cystinuria

1999 ◽  
Vol 10 (12) ◽  
pp. 4135-4147 ◽  
Author(s):  
Rahel Pfeiffer ◽  
Jan Loffing ◽  
Grégoire Rossier ◽  
Christian Bauch ◽  
Christian Meier ◽  
...  
Keyword(s):  
Amino Acid ◽  
Amino Acid Transport ◽  
Autosomal Recessive ◽  
Chromosomal Localization ◽  
Amino Acid Transporter ◽  
Type I ◽  
Acid Transport ◽  
Fusion Construct ◽  
Dibasic Amino Acid ◽  
Acid Transporter

Mutations of the glycoprotein rBAT cause cystinuria type I, an autosomal recessive failure of dibasic amino acid transport (b0,+ type) across luminal membranes of intestine and kidney cells. Here we identify the permease-like protein b0,+AT as the catalytic subunit that associates by a disulfide bond with rBAT to form a hetero-oligomeric b0,+amino acid transporter complex. We demonstrate its b0,+-type amino acid transport kinetics using a heterodimeric fusion construct and show its luminal brush border localization in kidney proximal tubule. These biochemical, transport, and localization characteristics as well as the chromosomal localization on 19q support the notion that the b0,+AT protein is the product of the gene defective in non-type I cystinuria.

Immunocytochemical localization of the renal neutral and basic amino acid transporter in rat adrenal gland, brainstem, and spinal cord

1995 ◽  
Vol 356 (4) ◽  
pp. 505-522 ◽  
Author(s):  
Melissa J. Nirenberg ◽  
Suresh S. Tate ◽  
Rachel Mosckovitz ◽  
Sidney Udenfriend ◽  
Virginia M. Pickel
Keyword(s):  
Spinal Cord ◽  
Amino Acid ◽  
Adrenal Gland ◽  
Basic Amino Acid ◽  
Amino Acid Transporter ◽  
Immunocytochemical Localization ◽  
Acid Transporter
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