CHIF, a member of the FXYD protein family, is a regulator of Na,K-ATPase distinct from the gamma-subunit
Details
Serval ID
serval:BIB_A5A4AC7FBCD9
Type
Article: article from journal or magazin.
Collection
Publications
Institution
Title
CHIF, a member of the FXYD protein family, is a regulator of Na,K-ATPase distinct from the gamma-subunit
Journal
EMBO Journal
ISSN
0261-4189 (Print)
Publication state
Published
Issued date
08/2001
Volume
20
Number
15
Pages
3993-4002
Notes
Journal Article
Research Support, Non-U.S. Gov't --- Old month value: Aug 1
Research Support, Non-U.S. Gov't --- Old month value: Aug 1
Abstract
The biological role of small membrane proteins of the new FXYD family is largely unknown. The best characterized FXYD protein is the gamma-subunit of the Na,K-ATPase (NKA) that modulates the Na,K-pump function in the kidney. Here, we report that, similarly to gamma(a) and gamma(b) splice variants, the FXYD protein CHIF (corticosteroid-induced factor) is a type I membrane protein which is associated with NKA in renal tissue, and modulates the Na,K-pump transport when expressed in Xenopus oocytes. In contrast to gamma(a) and gamma(b), which both decrease the apparent Na+ affinity of the Na,K-pump, CHIF significantly increases the Na+ affinity and decreases the apparent K+ affinity due to an increased Na+ competition at external binding sites. The extracytoplasmic FXYD motif is required for stable gamma-subunit and CHIF interaction with NKA, while cytoplasmic, positively charged residues are necessary for the gamma-subunit's association efficiency and for CHIF's functional effects. These data document that CHIF is a new tissue-specific regulator of NKA which probably plays a crucial role in aldosterone-responsive tissues responsible for the maintenance of body Na+ and K+ homeostasis.
Keywords
Alternative Splicing
Amino Acid Sequence
Animals
Humans
Isoenzymes/genetics/metabolism
Kidney/metabolism
Membrane Proteins/*metabolism
Molecular Sequence Data
Na(+)-K(+)-Exchanging ATPase/genetics/*metabolism
Oocytes/metabolism
Protein Processing, Post-Translational
Rats
Xenopus laevis
Pubmed
Web of science
Create date
24/01/2008 12:28
Last modification date
20/08/2019 15:10