Linked Life Data

11278434

Source:http://linkedlifedata.com/resource/pubmed/id/11278434

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
19
pubmed:dateCreated
2001-5-7
pubmed:abstractText
In oligomeric P2-ATPases such as Na,K- and H,K-ATPases, beta subunits play a fundamental role in the structural and functional maturation of the catalytic alpha subunit. In the present study we performed a tryptophan scanning analysis on the transmembrane alpha-helix of the Na,K-ATPase beta1 subunit to investigate its role in the stabilization of the alpha subunit, the endoplasmic reticulum exit of alpha-beta complexes, and the acquisition of functional properties of the Na,K-ATPase. Single or multiple tryptophan substitutions in the beta subunits transmembrane domain had no significant effect on the structural maturation of alpha subunits expressed in Xenopus oocytes nor on the level of expression of functional Na,K pumps at the cell surface. Furthermore, tryptophan substitutions in regions of the transmembrane alpha-helix containing two GXXXG transmembrane helix interaction motifs or a cysteine residue, which can be cross-linked to transmembrane helix M8 of the alpha subunit, had no effect on the apparent K(+) affinity of Na,K-ATPase. On the other hand, substitutions by tryptophan, serine, alanine, or cysteine, but not by phenylalanine of two highly conserved tyrosine residues, Tyr(40) and Tyr(44), on another face of the transmembrane helix, perturb the transport kinetics of Na,K pumps in an additive way. These results indicate that at least two faces of the beta subunits transmembrane helix contribute to inter- or intrasubunit interactions and that two tyrosine residues aligned in the beta subunits transmembrane alpha-helix are determinants of intrinsic transport characteristics of Na,K-ATPase.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
May
pubmed:issn
0021-9258
pubmed:author
pubmed:issnType
Print
pubmed:day
11
pubmed:volume
276
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
16356-64
pubmed:dateRevised
2007-11-15
pubmed:meshHeading
pubmed-meshheading:11278434-Amino Acid Sequence, pubmed-meshheading:11278434-Amino Acid Substitution, pubmed-meshheading:11278434-Animals, pubmed-meshheading:11278434-Cell Membrane, pubmed-meshheading:11278434-Endoplasmic Reticulum, pubmed-meshheading:11278434-Glycine, pubmed-meshheading:11278434-Kinetics, pubmed-meshheading:11278434-Membrane Potentials, pubmed-meshheading:11278434-Models, Molecular, pubmed-meshheading:11278434-Molecular Sequence Data, pubmed-meshheading:11278434-Mutagenesis, Site-Directed, pubmed-meshheading:11278434-Protein Structure, Secondary, pubmed-meshheading:11278434-Protein Subunits, pubmed-meshheading:11278434-Recombinant Proteins, pubmed-meshheading:11278434-Sodium-Potassium-Exchanging ATPase, pubmed-meshheading:11278434-Tryptophan, pubmed-meshheading:11278434-Xenopus
pubmed:year
2001
pubmed:articleTitle
Structural and functional features of the transmembrane domain of the Na,K-ATPase beta subunit revealed by tryptophan scanning.
pubmed:affiliation
Institut de Pharmacologie et Toxicologie de l'Université, rue du Bugnon 27, CH 1005-Lausanne, Switzerland.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't