Primary structure of an apical protein from Xenopus laevis that participates in amiloride-sensitive sodium channel activity.

Details

Serval ID
serval:BIB_FB9E24A7E6B9
Type
Article: article from journal or magazin.
Collection
Publications
Institution
Title
Primary structure of an apical protein from Xenopus laevis that participates in amiloride-sensitive sodium channel activity.
Journal
The Journal of cell biology
Author(s)
Staub O., Verrey F., Kleyman T.R., Benos D.J., Rossier B.C., Kraehenbuhl J.P.
ISSN
0021-9525
ISSN-L
0021-9525
Publication state
Published
Issued date
12/1992
Peer-reviewed
Oui
Volume
119
Number
6
Pages
1497-1506
Language
english
Notes
Publication types: Journal Article ; Research Support, Non-U.S. Gov't
Publication Status: ppublish
Abstract
High resistance epithelia express on their apical side an amiloride-sensitive sodium channel that controls sodium reabsorption. A cDNA was found to encode a 1,420-amino acid long polypeptide with no signal sequence, a putative transmembrane segment, and three predicted amphipathic alpha helices. A corresponding 5.2-kb mRNA was detected in Xenopus laevis kidney, intestine, and oocytes, with weak expression in stomach and eyes. An antibody directed against a fusion protein containing a COOH-terminus segment of the protein and an antiidiotypic antibody known to recognize the amiloride binding site of the epithelial sodium channel (Kleyman, T. R., J.-P. Kraehenbuhl, and S. A. Ernst. 1991. J. Biol. Chem. 266:3907-3915) immunoprecipitated a similar protein complex from [35S]methionine-labeled and from apically radioiodinated Xenopus laevis kidney-derived A6 cells. A single integral of 130-kD protein was recovered from samples reduced with DTT. The antibody also cross-reacted by ELISA with the putative amiloride-sensitive sodium channel isolated from A6 cells (Benos, D. J., G. Saccomani, and S. Sariban-Sohraby. 1987. J. Biol. Chem. 262:10613-10618). Although the protein is translated, cRNA injected into oocytes did not reconstitute amiloride-sensitive sodium transport, while antisense RNA or antisense oligodeoxynucleotides specific for two distinct sequences of the cloned cDNA inhibited amiloride-sensitive sodium current induced by injection of A6 cell mRNA. We propose that the cDNA encodes an apical plasma membrane protein that plays a role in the functional expression of the amiloride-sensitive epithelial sodium channel. It may represent a subunit of the Xenopus laevis sodium channel or a regulatory protein essential for sodium channel function.
Keywords
Amiloride/pharmacology, Amino Acid Sequence, Animals, Base Sequence, Bufo marinus, Cell Polarity, Cloning, Molecular, Epithelium, Gene Library, Kidney, Membrane Proteins/biosynthesis, Membrane Proteins/drug effects, Membrane Proteins/genetics, Molecular Sequence Data, Protein Conformation, RNA, Messenger/analysis, Sodium/metabolism, Sodium Channels/drug effects, Sodium Channels/genetics, Tissue Distribution, Xenopus Proteins, Xenopus laevis/genetics
Pubmed
Web of science
Open Access
Yes
Create date
24/01/2008 14:01
Last modification date
02/07/2024 8:40
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