Am J Physiol Cell Physiol Fuel your research with LabChart
HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
QUICK SEARCH:   [advanced]


     

Am J Physiol Cell Physiol 279: C1336-C1344, 2000;
0363-6143/00 $5.00
This Article
Right arrow Full Text
Right arrow Full Text (PDF)
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Right arrow Citation Map
Services
Right arrow Email this article to a friend
Right arrow Similar articles in this journal
Right arrow Similar articles in ISI Web of Science
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via ISI Web of Science (12)
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Nawrath, H.
Right arrow Articles by Closs, E. I.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Nawrath, H.
Right arrow Articles by Closs, E. I.
Vol. 279, Issue 5, C1336-C1344, November 2000

Voltage dependence of L-arginine transport by hCAT-2A and hCAT-2B expressed in oocytes from Xenopus laevis

Hermann Nawrath, Jörg W. Wegener, Johanna Rupp, Alice Habermeier, and Ellen I. Closs

Department of Pharmacology, Johannes Gutenberg University, 55101 Mainz, Germany

Membrane potential and currents were investigated with the two-electrode voltage-clamp technique in Xenopus laevis oocytes expressing hCAT-2A or hCAT-2B, the splice variants of the human cationic amino acid transporter hCAT-2. Both hCAT-2A- and hCAT-2B-expressing oocytes exhibited a negative extracellular L-arginine concentration ([L-Arg]o)-sensitive membrane potential, additive to the K+ diffusion potential, when cells were incubated in Leibovitz medium (containing 1.45 mM L-Arg and 0.25 mM L-lysine). The two carrier proteins produced inward and outward currents, which were dependent on the L-Arg gradient and membrane potential. Ion substitution experiments showed that the hCAT-induced currents were independent of external Na+, K+, Ca2+, or Mg2+. The apparent Michaelis-Menten constant values at -60 mV, obtained from plots of L-Arg-induced currents against [L-Arg]o, were 0.97 and 0.13 mM in oocytes expressing hCAT-2A and hCAT-2B, respectively; maximal currents amounted to -194 ± 8 and -84 ± 2 nA, respectively. At saturating [L-Arg]o, the current-voltage relationships of hCAT-2A-expressing oocytes became steeper, yielding an additional conductance up to 2 µS/oocyte, whereas those of hCAT-2B-expressing oocytes were simply shifted to the right, resulting in voltage-independent difference currents. The distinct electrochemical properties of the two isoforms of hCAT-2 are assumed to contribute differentially to the membrane transport and the maintenance of cationic amino acids in various tissues.

amino acid transporter; membrane current; two-electrode voltage clamp


This article has been cited by other articles:


Home page
 J. Physiol.Home page
R. D. Peluffo
L-Arginine currents in rat cardiac ventricular myocytes
J. Physiol., May 1, 2007; 580(3): 925 - 936.
[Abstract] [Full Text] [PDF]

Home page
 J. Physiol.Home page
C. V. Remillard and J. X.-J. Yuan
Cardiac L-arginine transport: the CAT is back
J. Physiol., May 1, 2007; 580(3): 699 - 700.
[Full Text] [PDF]

Home page
 J. Nutr.Home page
E. I. Closs, A. Simon, N. Vekony, and A. Rotmann
Plasma Membrane Transporters for Arginine
J. Nutr., October 1, 2004; 134(10): 2752S - 2759S.
[Abstract] [Full Text] [PDF]

Home page
 RNAHome page
D. FAULHAMMER, B. ESCHGFALLER, S. STARK, P. BURGSTALLER, W. ENGLBERGER, J. ERFURTH, F. KLEINJUNG, J. RUPP, S. D. VULCU, W. SCHRODER, et al.
Biostable aptamers with antagonistic properties to the neuropeptide nociceptin/orphanin FQ
RNA, March 1, 2004; 10(3): 516 - 527.
[Abstract] [Full Text] [PDF]

Home page
 Physiol. Rev.Home page
G. E. Mann, D. L. Yudilevich, and L. Sobrevia
Regulation of Amino Acid and Glucose Transporters in Endothelial and Smooth Muscle Cells
Physiol Rev, January 1, 2003; 83(1): 183 - 252.
[Abstract] [Full Text] [PDF]


HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
Visit Other APS Journals Online