Degradation and endoplasmic reticulum retention of unassembled alpha- and beta-subunits of Na,K-ATPase correlate with interaction of BiP

Details

Serval ID
serval:BIB_803C50EAD037
Type
Article: article from journal or magazin.
Collection
Publications
Institution
Title
Degradation and endoplasmic reticulum retention of unassembled alpha- and beta-subunits of Na,K-ATPase correlate with interaction of BiP
Journal
Journal of Biological Chemistry
Author(s)
Beggah  A., Mathews  P., Beguin  P., Geering  K.
ISSN
0021-9258 (Print)
Publication state
Published
Issued date
08/1996
Volume
271
Number
34
Pages
20895-902
Notes
Comparative Study
Journal Article
Research Support, Non-U.S. Gov't
Research Support, U.S. Gov't, P.H.S. --- Old month value: Aug 23
Abstract
Assembly of alpha- and beta-subunits in the endoplasmic reticulum is a prerequisite for the structural and functional maturation of oligomeric P-type ATPases. In Xenopus oocytes, overexpressed, unassembled alpha- and beta-subunits of Xenopus Na,K-ATPase are retained in the endoplasmic reticulum (ER) and are degraded with different kinetics, while unassembled beta-subunits of gastric H, K-ATPase leave the ER. In this study, we have investigated the role of the immunoglobulin-binding protein, BiP, in the folding, assembly, and ER retention of ATPase subunits. We determined the primary sequence of Xenopus BiP and used polyclonal antibodies to examine the interaction with BiP of various wild type and mutant alpha- and beta-subunits overexpressed in Xenopus oocytes. Our results show that ER-retained, unassembled Na,K-ATPase beta-subunits, but not transport-competent H,K-ATPase beta-subunits, efficiently associate with BiP until assembly with alpha-subunits occurs. Furthermore, the kinetics of BiP interaction with unassembled wild type and with mutant Na,K-ATPase beta-subunits parallels their respective stability against cellular degradation. Finally, alpha-subunits that are overexpressed in oocytes and are rapidly degraded and endogenous oocyte alpha-subunits that are stably expressed as individual assembly-competent proteins also interact with oocyte or exogenous BiP, and the interaction time correlates with the protein's stability. These data demonstrate for the first time that BiP might be involved in a long term maturation arrest and/or in the ER quality control of a multimembrane-spanning protein and lend support for a universal chaperone function of BiP.
Keywords
Animals Base Sequence Biological Transport Carrier Proteins/*metabolism Cell Compartmentation Cloning, Molecular DNA Primers/chemistry DNA, Complementary/genetics Endoplasmic Reticulum, Rough/*metabolism H(+)-K(+)-Exchanging ATPase/*metabolism *Heat-Shock Proteins Macromolecular Substances Molecular Chaperones/*metabolism Molecular Sequence Data Na(+)-K(+)-Exchanging ATPase/chemistry/*metabolism Oocytes Precipitin Tests Protein Binding Protein Folding Rats Sequence Alignment Sequence Homology, Amino Acid Xenopus laevis
Pubmed
Web of science
Create date
24/01/2008 12:28
Last modification date
20/08/2019 14:40
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