| Literature DB >> 17078968 |
Sonali P Barwe1, Sanguk Kim, Sigrid A Rajasekaran, James U Bowie, Ayyappan K Rajasekaran.
Abstract
Na,K-ATPase is a hetero-oligomer of alpha and beta-subunits. The Na,K-ATPase beta-subunit (Na,K-beta) is involved in both the regulation of ion transport activity, and in cell-cell adhesion. By structure prediction and evolutionary analysis, we identified two distinct faces on the Na,K-beta transmembrane domain (TMD) that could mediate protein-protein interactions: a glycine zipper motif and a conserved heptad repeat. Here, we show that the heptad repeat face is involved in the hetero-oligomeric interaction of Na,K-beta with Na,K-alpha, and the glycine zipper face is involved in the homo-oligomerization of Na,K-beta. Point mutations in the heptad repeat motif reduced Na,K-beta binding to Na,K-alpha, and Na,K-ATPase activity. Na,K-beta TMD homo-oligomerized in biological membranes, and mutation of the glycine zipper motif affected oligomerization and cell-cell adhesion. These results provide a structural basis for understanding how Na,K-beta links ion transport and cell-cell adhesion.Entities:
Mesh：
Substances：
Year: 2006 PMID： 17078968 PMCID： PMC2459552 DOI： 10.1016/j.jmb.2006.10.029
Source DB: PubMed Journal: J Mol Biol ISSN： 0022-2836 Impact factor: 5.469