Maturation of the catalytic alpha-subunit of Na,K-ATPase during intracellular transport

Details

Serval ID
serval:BIB_00A68BEDB081
Type
Article: article from journal or magazin.
Collection
Publications
Institution
Title
Maturation of the catalytic alpha-subunit of Na,K-ATPase during intracellular transport
Journal
Journal of Cell Biology
Author(s)
Geering  K., Kraehenbuhl  J. P., Rossier  B. C.
ISSN
0021-9525
Publication state
Published
Issued date
12/1987
Peer-reviewed
Oui
Volume
105
Number
6 Pt 1
Pages
2613-9
Notes
Journal Article
Research Support, Non-U.S. Gov't --- Old month value: Dec
Abstract
The protease sensitivity of the catalytic alpha-subunit of Na,K-ATPase during intracellular transport along the exocytic pathway has been investigated in two amphibian epithelial cell lines. Controlled trypsinolysis followed by immunoprecipitation of cell homogenates or microsomal fractions from [35S]methionine pulse-chased A6 kidney cells revealed distinct cleavage patterns by SDS-PAGE. Shortly after synthesis (7-min pulse), the 98-kD alpha-subunit is fully sensitive to trypsin digestion and is cleaved into a 35-kD membrane-bound and a 27.5-kD soluble peptide. With a 15-min pulse, 10% of the newly synthesized polypeptide becomes resistant to trypsin digestion. With longer chase time, the proportion of protease-resistant alpha-subunit further increases. Concomitantly, the alpha-subunit acquires the ability to undergo cation-dependent conformational transitions, as reflected by distinct tryptic digest patterns in the presence of Na+ or K+. Similar results were obtained in TBM cells, a toad bladder cell line. Our data indicate that the catalytic subunit of Na,K-ATPase is structurally rearranged during intracellular transport from its site of synthesis to its site of action at the cell surface, a modification which might mark the functional maturation of the enzyme.
Keywords
Animals Biological Transport Bufo marinus Cell Line Exocytosis Kinetics Macromolecular Substances Na(+)-K(+)-Exchanging ATPase/*biosynthesis Peptide Fragments/analysis Protein Conformation Trypsin Xenopus laevis
Pubmed
Web of science
Open Access
Yes
Create date
24/01/2008 13:01
Last modification date
20/08/2019 12:22
Usage data