title: Splice variants of the gamma subunit (FXYD2) and their significance in regulation of the Na, K-ATPase in kidney.
abstract: The recent discovery of a family of single-span membrane proteins (the FXYD proteins) introduced a new direction to the rather complicated area of regulation of Na, K-ATPase. At least six members of the family have been shown to associate with the Na, K-ATPase in a cell- and tissue-specific manner, while four of them, namely the gamma subunit (FXYD2), CHIF (FXYD4), phospholemman (FXYD1), and dysadherin (FXYD5) have been identified in kidney. All four exhibited different effects on the properties of the pump in heterologous expression systems. Taken along with their non-overlapping expression patterns in the nephron, this provides a potential structural basis for the segment-specific properties of the Na, K-ATPase that had been reported in a number of papers on kidney physiology. This brief review summarizes our own contributions on structure/functional characterization of one of the family members, the gamma subunit (FXYD2). The focus is on splice variants of gamma, their structural similarity and yet distinct effects conferred to Na, K-ATPase.
authors.affiliation: Laboratory of Membrane Biology, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts, USA.
authors.forename: Elena
authors.initials: E
authors.lastname: Arystarkhova
authors.forename: Kathleen J
authors.initials: KJ
authors.lastname: Sweadner
mesh_terms: D017398:Alternative Splicing; D000818:Animals; D049109:Cell Proliferation; D006801:Humans; D007527:Isoenzymes; D007668:Kidney / Q000201:enzymology*; D008565:Membrane Proteins / Q000737:chemistry / Q000235:genetics / Q000502:physiology; D010750:Phosphoproteins / Q000737:chemistry / Q000235:genetics / Q000502:physiology; D011487:Protein Conformation; D021122:Protein Subunits; D000254:Sodium-Potassium-Exchanging ATPase / Q000737:chemistry / Q000235:genetics* / Q000502:physiology
chemical_list: D007527:Isoenzymes; D008565:Membrane Proteins; D010750:Phosphoproteins; D021122:Protein Subunits; C069141:phospholemman; C416502:FXYD2 protein, human; D000254:Sodium-Potassium-Exchanging ATPase