Click here to close
Hello! We notice that you are using Internet Explorer, which is not supported by Xenbase and may cause the site to display incorrectly.
We suggest using a current version of Chrome,
FireFox, or Safari.
Characterization of the endogenous carnitine transport and expression of a rat renal Na(+)-dependent carnitine transport system in Xenopus laevis oocytes.
Berardi S
,
Hagenbuch B
,
Carafoli E
,
Krähenbühl S
.
???displayArticle.abstract???
L-Carnitine transport was characterized in Xenopus laevis oocytes before and after injection of mRNA isolated from rat renal cortex. Non-injected oocytes revealed endogenous Na(+)-dependent transport of L-carnitine. After injection of 15 ng of rat kidney mRNA, the Na(+)-dependent L-carnitine transport increased 2-3-fold, reaching maximal activity after 5-6 days. The expressed carnitine transport was maximal at pH 7.5, whereas the endogenous transport showed no clear maximum between pH 6.0 and 8.5. Kinetic analysis revealed apparent Km values for L-carnitine of 66 microM for the endogenous and 149 microM for the expressed transport. Trimethyl-lysine and D-carnitine inhibited both the endogenous and the expressed transport. In contrast, L-acetylcarnitine, L-isovalerylcarnitine, L-palmitoylcarnitine and butyrobetaine inhibited predominantly the expressed transport, whereas glycinebetaine had no inhibitory effect on either transport system. Size-fractionated rat renal-cortex mRNA (median size 2 kb) induced a 3-fold higher L-carnitine transport than did unfractionated mRNA. These studies demonstrate that Xenopus laevis oocytes exhibit Na(+)-dependent L-carnitine transport and provide the basis for expression-cloning of a rat renal Na(+)-dependent L-carnitine transport system.
Bieber,
Possible functions of short-chain and medium-chain carnitine acyltransferases.
1982, Pubmed
Bieber,
Possible functions of short-chain and medium-chain carnitine acyltransferases.
1982,
Pubmed
Brass,
Relationship between acid-soluble carnitine and coenzyme A pools in vivo.
1980,
Pubmed
Bremer,
Carnitine--metabolism and functions.
1983,
Pubmed
Chomczynski,
Single-step method of RNA isolation by acid guanidinium thiocyanate-phenol-chloroform extraction.
1987,
Pubmed
Engel,
Carnitine deficiency of human skeletal muscle with associated lipid storage myopathy: a new syndrome.
1973,
Pubmed
FRITZ,
The effect of muscle extracts on the oxidation of palmitic acid by liver slices and homogenates.
1955,
Pubmed
Hagenbuch,
Expression of the hepatocyte Na+/bile acid cotransporter in Xenopus laevis oocytes.
1990,
Pubmed
,
Xenbase
Hagenbuch,
Functional expression cloning and characterization of the hepatocyte Na+/bile acid cotransport system.
1991,
Pubmed
,
Xenbase
Horiuchi,
Primary defect of juvenile visceral steatosis (jvs) mouse with systemic carnitine deficiency is probably in renal carnitine transport system.
1994,
Pubmed
Keene,
Myocardial L-carnitine deficiency in a family of dogs with dilated cardiomyopathy.
1991,
Pubmed
Li,
Uptake of L-carnitine by rat jejunal brush border microvillous membrane vesicles. Evidence of passive diffusion.
1990,
Pubmed
Ramsay,
The carnitine acyltransferases and their role in modulating acyl-CoA pools.
1993,
Pubmed
Rebouche,
Sodium gradient-stimulated transport of L-carnitine into renal brush border membrane vesicles: kinetics, specificity, and regulation by dietary carnitine.
1984,
Pubmed
Robey,
Induction of glycinebetaine uptake into Xenopus oocytes by injection of poly(A)+ RNA from renal cells exposed to high extracellular NaCl.
1991,
Pubmed
,
Xenbase
Rodrigues Pereira,
Cardiomyopathy associated with carnitine loss in kidneys and small intestine.
1988,
Pubmed
Treem,
Primary carnitine deficiency due to a failure of carnitine transport in kidney, muscle, and fibroblasts.
1988,
Pubmed
Vary,
Characterization of carnitine transport in isolated perfused adult rat hearts.
1982,
Pubmed
Wallace,
Protein incorporation by isolated amphibian oocytes. 3. Optimum incubation conditions.
1973,
Pubmed
,
Xenbase
Yamauchi,
Cloning of a Na(+)- and Cl(-)-dependent betaine transporter that is regulated by hypertonicity.
1992,
Pubmed
,
Xenbase
Zimmerli,
Multispecificity of Na+-dependent taurocholate uptake in basolateral (sinusoidal) rat liver plasma membrane vesicles.
1989,
Pubmed