Does the colonic H,K-ATPase also act as an Na,K-ATPase?

被引:70
作者
Cougnon, M
Bouyer, P
Planelles, G
Jaisser, F
机构
[1] Univ Paris 05, Fac Med Necker, INSERM U467, F-75015 Paris, France
[2] Univ Paris 07, INSERM U246, Fac Med Xavier Bichat, F-75018 Paris, France
关键词
D O I
10.1073/pnas.95.11.6516
中图分类号
O [数理科学和化学]; P [天文学、地球科学]; Q [生物科学]; N [自然科学总论];
学科分类号
07 ; 0710 ; 09 ;
摘要
We previously have demonstrated that the colonic P-ATPase alpha subunit cDNA encodes an H,K-ATPase when expressed in Xenopus laevis oocytes. Besides its high level of amino acid homology (75%) with the Na,K-ATPase, the colonic H,K-ATPase also shares a common pharmacological profile with Na,K-ATPase, because both are ouabain-sensitive and Sch 28080-insensitive. These features raise the possibility that an unrecognized property of the colonic H,K-ATPase would be Na+ translocation. To test this hypothesis, ion-selective microelectrodes were used to measure the intracellular Na+ activity of X. laevis oocytes expressing various combinations of P-ATPase subunits. The results show that expression in oocytes of the colonic H,K-ATPase affects intracellular Naf homeostasis in a way similar to the expression of the Bufo marinus Na,K-ATPase; intracellular Na+ activity is lower in oocytes expressing the colonic H,K-ATPase or the B. marinas Na,K-ATPase than in oocytes expressing the gastric H,K-ATPase or a beta subunit alone. In oocytes expressing the colonic H,K-ATPase, the decrease in intracellular Naf activity persists when diffusive Na+ influx is enhanced by functional expression of the amiloride-sensitive epithelial Na+ channel, suggesting that the decrease is related to increased active Na+ efflux. The Na+ decrease depends on the presence of K+ in the external medium and is inhibited by 2 mM ouabain, a concentration that inhibits the colonic H,K-ATPase. These data are consistent with the hypothesis that the colonic H,K-ATPase may transport Na+, acting as an (Na,H),K-ATPase. Despite its molecular and functional characterization, the physiological role of the colonic (Na,H),K-ATPase in colonic and renal ion homeostasis remains to be elucidated.
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页码:6516 / 6520
页数:5
相关论文
共 28 条
[1]   CELL AND LUMINAL ACTIVITIES OF CHLORIDE, POTASSIUM, SODIUM AND PROTONS IN THE LATE DISTAL TUBULE OF NECTURUS KIDNEY [J].
ANAGNOSTOPOULOS, T ;
PLANELLES, G .
JOURNAL OF PHYSIOLOGY-LONDON, 1987, 393 :73-89
[2]   POTASSIUM TRANSLOCATION BY THE NA+/K+ PUMP IS VOLTAGE INSENSITIVE [J].
BAHINSKI, A ;
NAKAO, M ;
GADSBY, DC .
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA, 1988, 85 (10) :3412-3416
[3]   K depletion modifies the properties of Sch-28080-sensitive K-ATPase in rat collecting duct [J].
BuffinMeyer, B ;
YounesIbrahim, M ;
BarletBas, C ;
Cheval, L ;
Marsy, S ;
Doucet, A .
AMERICAN JOURNAL OF PHYSIOLOGY-RENAL PHYSIOLOGY, 1997, 272 (01) :F124-F131
[4]   AMILORIDE-SENSITIVE EPITHELIAL NA+ CHANNEL IS MADE OF 3 HOMOLOGOUS SUBUNITS [J].
CANESSA, CM ;
SCHILD, L ;
BUELL, G ;
THORENS, B ;
GAUTSCHI, I ;
HORISBERGER, JD ;
ROSSIER, BC .
NATURE, 1994, 367 (6462) :463-467
[5]   EPITHELIAL SODIUM-CHANNEL RELATED TO PROTEINS INVOLVED IN NEURODEGENERATION [J].
CANESSA, CM ;
HORISBERGER, JD ;
ROSSIER, BC .
NATURE, 1993, 361 (6411) :467-470
[6]   MUTATION OF A CYSTEINE IN THE 1ST TRANSMEMBRANE SEGMENT OF NA,K-ATPASE ALPHA SUBUNIT CONFERS OUABAIN RESISTANCE [J].
CANESSA, CM ;
HORISBERGER, JD ;
LOUVARD, D ;
ROSSIER, BC .
EMBO JOURNAL, 1992, 11 (05) :1681-1687
[7]   Functional expression of the colonic H+,K+-ATPase alpha-subunit - Pharmacologic properties and assembly with X(+),K+-ATPase beta-subunits [J].
Codina, J ;
Kone, BC ;
DelmasMata, JT ;
Dubose, TD .
JOURNAL OF BIOLOGICAL CHEMISTRY, 1996, 271 (47) :29759-29763
[8]   Further investigation of ionic diffusive properties and of NH4+ pathways in Xenopus laevis oocyte cell membrane [J].
Cougnon, M ;
Bouyer, P ;
Hulin, P ;
Anagnostopoulos, T ;
Planelles, G .
PFLUGERS ARCHIV-EUROPEAN JOURNAL OF PHYSIOLOGY, 1996, 431 (04) :658-667
[9]   The rat distal colon P-ATPase alpha subunit encodes a ouabain-sensitive H+,K+-ATPase [J].
Cougnon, M ;
Planelles, G ;
Crowson, MS ;
Shull, GE ;
Rossier, BC ;
Jaisser, F .
JOURNAL OF BIOLOGICAL CHEMISTRY, 1996, 271 (13) :7277-7280
[10]  
CROWSON MS, 1992, J BIOL CHEM, V267, P13740