Abstract
Recently we have identified mRNA encoding a hitherto unknown mammalian X,K-ATPase beta-subunit expressed predominantly in muscle tissue (Pestov, N. B. et al. (1999) FEBS Lett. 456, 243-248). Here we demonstrate the existence of the predicted protein, designated as beta(m) (beta(muscle)), in human adult skeletal muscle membranes using immunoblotting with beta(m)-specific antibodies generated against recombinant polypeptide formed by extramembrane beta(m) domains. The electrophoretic mobility of beta(m) was shown to be abnormally low due to the presence of Glu-rich sequences. In contrast to mature forms of other known X,K-ATPase beta-subunits, carbohydrate moiety of beta(m) is sensitive to endoglycosidase H and appears to be composed of short high-mannose or hybrid N-glycans. This finding argues in favor of an intracellular location of beta(m) in human skeletal muscle.
Copyright 2000 Academic Press.
Publication types
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Research Support, Non-U.S. Gov't
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Research Support, U.S. Gov't, P.H.S.
MeSH terms
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Amino Acid Sequence
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Base Sequence
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Blotting, Western
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Catalysis
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Electrophoresis, Polyacrylamide Gel
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Female
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Glutamic Acid / chemistry
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Glycoside Hydrolases / metabolism
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Glycosylation
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H(+)-K(+)-Exchanging ATPase / biosynthesis*
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H(+)-K(+)-Exchanging ATPase / chemistry*
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Humans
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Immunoblotting
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Mannose / chemistry
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Middle Aged
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Molecular Sequence Data
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Muscle, Skeletal / enzymology*
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Muscle, Skeletal / metabolism*
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Myocardium / metabolism
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Polysaccharides / chemistry
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Protein Isoforms
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Protein Structure, Tertiary
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Recombinant Proteins / metabolism
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Reverse Transcriptase Polymerase Chain Reaction
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Sequence Homology, Amino Acid
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Sodium-Potassium-Exchanging ATPase / biosynthesis*
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Sodium-Potassium-Exchanging ATPase / chemistry*
Substances
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Polysaccharides
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Protein Isoforms
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Recombinant Proteins
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Glutamic Acid
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Glycoside Hydrolases
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H(+)-K(+)-Exchanging ATPase
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Sodium-Potassium-Exchanging ATPase
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Mannose