Na,K-ATPase in dog red cells. Immunological identification and maturation-associated degradation by the proteolytic system.
The Na,K-ATPase of red cells from high K+ and low K+ dogs was studied immunologically by using antibodies raised against dog kidney enzyme. Anti-alpha subunit IgGs, which also recognized alpha (+) from brain enzyme, identified the larger subunit of erythrocyte Na,K-ATPase as a homogeneous polypeptide with Mr = 96,000 on sodium dodecyl sulfate-polyacrylamide gel electrophoresis followed by immunoblotting. In addition, erythrocyte Na,K-ATPase, purified by immunoaffinity chromatography on a monoclonal antibody-coupled column, showed the identity of its polypeptide composition to that of the renal enzyme. Furthermore, it was shown that reticulocyte lysates from high K+ and low K+ dogs substantially degraded 125I-Bolton-Hunter reagent-labeled Na,K-ATPase. This degradation of the enzyme protein was significantly enhanced by the addition of ATP and Mg2+. These results indicate that dog reticulocytes possess some mechanism for protein breakdown involving an ATP-dependent proteolytic system, resulting in the dramatic breakdown of Na,K-ATPase activity during dog reticulocyte maturation into erythrocytes (Maede, Y., and Inaba, M. (1985) J. Biol. Chem. 260, 3337-3343).
D000818:Animals; D002846:Chromatography, Affinity; D003429:Cross Reactions; D004285:Dogs; D004591:Electrophoresis, Polyacrylamide Gel; D004912:Erythrocytes / Q000201:enzymology*; D006412:Hematopoietic Stem Cells / Q000201:enzymology; D007074:Immunoglobulin G / Q000276:immunology; D008970:Molecular Weight; D010447:Peptide Hydrolases / Q000378:metabolism*; D012156:Reticulocytes / Q000201:enzymology; D000254:Sodium-Potassium-Exchanging ATPase / Q000097:blood* / Q000276:immunology
D007074:Immunoglobulin G; D010447:Peptide Hydrolases; D000254:Sodium-Potassium-Exchanging ATPase