FXYD7, mapping of functional sites involved in endoplasmic reticulum export, association with and regulation of Na,K-ATPase.

Details

Serval ID
serval:BIB_9A19D8B09CF6
Type
Article: article from journal or magazin.
Collection
Publications
Institution
Title
FXYD7, mapping of functional sites involved in endoplasmic reticulum export, association with and regulation of Na,K-ATPase.
Journal
Journal of Biological Chemistry
Author(s)
Crambert G., Li C., Swee L.K., Geering K.
ISSN
0021-9258
Publication state
Published
Issued date
07/2004
Peer-reviewed
Oui
Volume
279
Number
29
Pages
30888-30895
Language
english
Notes
Publication types: Journal Article
Abstract
The brain-specific FXYD7 is a member of the recently defined FXYD family that associates with the alpha1-beta1 Na,K-ATPase isozyme and induces an about 2-fold decrease in its apparent K+ affinity. By using the Xenopus oocyte as an expression system, we have investigated the role of conserved and FXYD7-specific amino acids in the cellular routing of FXYD7 and in its association with and regulation of Na,K-ATPase. In contrast to FXYD2 and FXYD4, the studies on FXYD7 show that the conserved FXYD motif in the extracytoplasmic domain is not involved in the efficient association of FXYD7 with Na,K-ATPase. On the other hand, the conserved Gly40 and Gly29, located on the same face of the transmembrane helix, were found to be implicated both in the association with and the regulation of Na,K-ATPase. Mutational analysis of FXYD7-specific regions revealed the presence of an ER export signal at the end of the cytoplasmic tail. Deletion of a C-terminal valine residue in FXYD7 significantly delayed and decreased its O-glycosylation processing and retarded the rate of its cell surface expression. This result indicates that the C-terminal valine residue is involved in the rapid and selective ER export of FXYD7, which could explain the observed post-translational association of FXYD7 with Na,K-ATPase. In conclusion, our study on FXYD7 provides new information on structural determinants of general importance for FXYD protein action. Moreover, FXYD7 is identified as a new member of proteins with a regulated ER export, which suggests that, among FXYD proteins, FXYD7 has a particular regulatory function in brain.
Keywords
Amino Acid Motifs, Amino Acid Sequence, Animals, Binding Sites, Brain/metabolism, Cell Membrane/metabolism, Cytoplasm/metabolism, DNA Mutational Analysis, DNA, Complementary/metabolism, Electrophysiology, Endoplasmic Reticulum/metabolism, Gene Deletion, Glycine/chemistry, Glycosylation, Membrane Glycoproteins/metabolism, Membrane Glycoproteins/physiology, Mice, Molecular Sequence Data, Mutation, Nerve Tissue Proteins/metabolism, Nerve Tissue Proteins/physiology, Oocytes/metabolism, Protein Binding, Protein Isoforms, Protein Structure, Tertiary, Sequence Homology, Amino Acid, Sodium-Potassium-Exchanging ATPase/chemistry, Sodium-Potassium-Exchanging ATPase/metabolism, Time Factors, Valine/chemistry, Xenopus, Xenopus laevis
Pubmed
Web of science
Open Access
Yes
Create date
24/01/2008 12:28
Last modification date
20/08/2019 15:01
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