Role of specific acidic lipids on the reconstitution of sodium-dependent amino acid transport in proteoliposomes derived from Ehrlich cell plasma membranes

Biochemistry ◽  
1990 ◽  
Vol 29 (19) ◽  
pp. 4575-4581 ◽  
Author(s):  
Guorong Lin ◽  
John I. McCormick ◽  
Sirano Dhe-Paganon ◽  
John R. Silvius ◽  
Rose M. Johnstone
Keyword(s):  
Amino Acid ◽  
Amino Acid Transport ◽  
Plasma Membranes ◽  
Acid Transport ◽  
Ehrlich Cell ◽  
Cell Plasma ◽  
Sodium Dependent ◽  
Acidic Lipids

scholarly journals Identification of the integrin α3β1 as a component of a partially purified A-system amino acid transporter from Ehrlich cell plasma membranes

1995 ◽  
Vol 311 (3) ◽  
pp. 743-751 ◽  
Author(s):  
J I McCormick ◽  
R M Johnstone
Keyword(s):  
Amino Acid ◽  
Amino Acid Transport ◽  
Plasma Membranes ◽  
Amino Acid Transporter ◽  
Acid Transport ◽  
Transport Activity ◽  
Western Blots ◽  
Ehrlich Cell ◽  
Cell Plasma ◽  
Beta 1 Integrin

We have previously reported [McCormick and Johnstone (1988) Proc. Natl. Acad. Sci. U.S.A. 85, 7877-7881] the partial purification of the Na(+)-dependent A-system amino acid transporter from Ehrlich cell plasma membranes and have suggested that a 120-130 kDa peptide, a major component of the purified fraction [octyl glucoside (OG) extract], is involved in Na(+)-dependent amino acid transport. In the present study, N-terminal sequence analysis of the 120-130 kDa peptide revealed a sequence similar to that of the alpha 3 subunit of the integrin alpha 3 beta 1. The presence of alpha 3 beta 1 was confirmed by Western blots of the OG extract probed with anti-alpha 3 or -beta 1 antibodies. Western blots also showed that an antibody originally raised against the 120-130 kDa peptide crossreacts with both the alpha 3 and beta 1 integrin subunits. Co-purification of alpha 3 beta 1 and Na(+)-dependent transport activity suggested that the two activities might be associated. Evidence that alpha 3 plays a role in transport is shown by the fact that an antibody against human alpha 3, but not beta 1, removed transport activity (approximately 25% loss) from cholate-solubilized Ehrlich membranes. Further purification of OG extracts using concanavalin A and wheat-germ lectin columns resulted in the separation of transport activity from the bulk (but not all) of alpha 3 beta 1 integrin without loss of the transport activity. These results indicate that the integrin itself is not essential for amino acid transport. Reconstitution of a purified alpha 3 beta 1-depleted protein fraction showed high levels of Na(+)-dependent, alpha-methylaminoisobutyric-acid-inhibitable amino acid transport in proteoliposomes, whereas reconstituted integrin alone showed little transport activity. However, in the integrin-depleted fractions, high amino acid uptake occurred in K+ which compromised the accurate measurement of the Na(+)-dependent component of uptake. The data suggest that alpha 3 may be associated with the A-system transporter and may modulate the activity of this carrier. Moreover, transfection of K562 and RD cells with human alpha 3 and alpha 2 cDNA showed that the former but not the latter increased A-system transport, thus providing more direct evidence that alpha 3 may modulate A-system transport activity.

scholarly journals A rapid method for the functional reconstitution of amino acid transport systems from rat liver plasma membranes. Partial purification of System A

1988 ◽  
Vol 255 (3) ◽  
pp. 963-969 ◽  
Author(s):  
A R Quesada ◽  
J D McGivan
Keyword(s):  
Amino Acid ◽  
Rapid Method ◽  
Amino Acid Transport ◽  
Plasma Membranes ◽  
Transport Systems ◽  
Partial Purification ◽  
Acid Transport ◽  
Transport Activity ◽  
System A ◽  
System L

A rapid method for the functional reconstruction of amino acid transport from liver plasma-membrane vesicles using the neutral detergent decanoyl-N-glucamide (‘MEGA-10’) is described. The method is a modification of that previously employed in this laboratory for reconstitution of amino acid transport systems from kidney brush-border membranes [Lynch & McGivan (1987) Biochem. J. 244, 503-508]. The transport activities termed ‘System A’, ‘System N’, and ‘System L’ are all reconstituted. The reconstitution procedure is rapid and efficient and is suitable as an assay for transport activity in studies involving membrane fractionation. By using this reconstitution procedure, System A transport activity was partially purified by lectin-affinity chromatography.

Role of the gamma-glutamyl cycle in the regulation of amino acid translocation

1989 ◽  
Vol 257 (6) ◽  
pp. E916-E922 ◽  
Author(s):  
J. R. Vina ◽  
M. Palacin ◽  
I. R. Puertes ◽  
R. Hernandez ◽  
J. Vina
Keyword(s):  
Amino Acids ◽  
Mammary Gland ◽  
Amino Acid ◽  
Amino Acid Transport ◽  
Acid Transport ◽  
Pregnant Rats ◽  
Gamma Glutamyl ◽  
Extracellular Signals ◽  
Previously Treated

Amino acid translocation was studied in the mammary gland of lactating rats and in the placenta of pregnant rats. The uptake of amino acids by the mammary gland is maximal on days 10-14 of lactation and is minimal on days 19-21. However, on day 19 maximal uptake can be restored by injection of 1) small amounts of gamma-glutamyl amino acids, 2) 5-oxoproline, and 3) an inhibitor of 5-oxoprolinase. A severe decrease in uptake of amino acids at the peak of lactation is provoked by anthglutin, an inhibitor of gamma-glutamyltranspeptidase (GGT). Simultaneous injection of 5-oxoproline blocks these effects of anthglutin. In pregnant rats, inhibition (79%) of placental GGT activity by acivicin results in a 50% decrease of placental L-[U-14C]-alanine transfer and 70-80% decrease in its incorporation into the placental and fetal proteins. Infusion of 5-oxoproline to mothers previously treated with acivicin restored the L-[U-14C]-alanine transfer. Acivicin or 5-oxoproline did not modify the transfer and metabolism of D-[U14C]glucose by the fetal placental unit. These results show that the gamma-glutamyl cycle should not be considered a mechanism for amino acid transport but rather a generator of extracellular signals, gamma-glutamyl amino acids, that are converted intracellularly to 5-oxoproline, which activates uptake and/or metabolism of amino acids.

scholarly journals Role of Oxoproline in the Regulation of Neutral Amino Acid Transport across the Blood-Brain Barrier

1996 ◽  
Vol 271 (32) ◽  
pp. 19129-19133 ◽  
Author(s):  
Wha-Joon Lee ◽  
Richard A. Hawkins ◽  
Darryl R. Peterson ◽  
Juan R. Viña
Keyword(s):  
Amino Acid ◽  
Blood Brain Barrier ◽  
Amino Acid Transport ◽  
Neutral Amino Acid ◽  
Brain Barrier ◽  
Acid Transport ◽  
Blood Brain

scholarly journals The role of system A for neutral amino acid transport in the regulation of cell volume

2001 ◽  
Vol 18 (1) ◽  
pp. 27-38 ◽  
Author(s):  
Ovidio Bussolati ◽  
Valeria Dall'Asta ◽  
Renata Franchi-Gazzola ◽  
Roberto Sala ◽  
Bianca Maria Rotoli ◽  
...  
Keyword(s):  
Amino Acid ◽  
Cell Volume ◽  
Amino Acid Transport ◽  
Neutral Amino Acid ◽  
Acid Transport ◽  
System A
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