Subcellular distribution and immunocytochemical localization of Na,K-ATPase subunit isoforms in human skeletal muscle
- 1 January 1994
- journal article
- research article
- Published by Taylor & Francis Ltd in Molecular Membrane Biology
- Vol. 11 (4), 255-262
- https://doi.org/10.3109/09687689409160435
Abstract
The expression of Na,K-ATPase isoforms was investigated in human skeletal muscle membranes isolated by subcellular fractionation. The alpha 1, alpha 2, alpha 3 and beta 1 subunits were detectable in membranes prepared from the human soleus muscle. The alpha 1 subunit was largely detected in a fraction enriched with plasma membranes (PM), its abundance in an intracellular membrane fraction (IM) accounted for only 4% of that in the PM fraction. No alpha 1 subunits were detected in membranes of sarcoplasmic reticulum (SR) origin. The PM and IM fractions were enriched with alpha 2 subunits which were less abundant in the SR-enriched fraction. The abundance of alpha 2 molecules within the IM fraction was about 75% of that in the PM fraction when the total protein content for the two fractions was taken into account. Immunocytochemical studies confirmed the localization of the alpha 1 subunit to the muscle cell surface. The alpha 2 subunit was also found to be present in the cell surface but the observation that alpha 2 immunofluorescence was diffusely dispersed throughout the muscle fibre indicated that it was also present intracellularly, consistent with its biochemical localization in the PM and IM membrane fractions. The alpha 3 subunit was detected largely in the PM fraction but the lack of good antibodies to this isoform precluded an analysis of its immunocytochemical localization. The beta 1 subunit was enriched in the PM fraction but was also detected to a modest extent in the IM.(ABSTRACT TRUNCATED AT 250 WORDS)Keywords
This publication has 35 references indexed in Scilit:
- Expression of β subunit isoforms of the Na+,K+‐ATPase is muscle type‐specificFEBS Letters, 1993
- The functional role of the β‐subunit in the maturation and intracellular transport of Na,K‐ATPaseFEBS Letters, 1991
- Mutual dependence of Na,K‐ATPase α‐ and β‐subunits for correct posttranslational processing and intracellular transportFEBS Letters, 1990
- Isozymes of the Na+/K+-ATPaseBiochimica et Biophysica Acta (BBA) - Reviews on Biomembranes, 1989
- Antisera specific for the .alpha.1, .alpha.2, .alpha.3, and .beta. subunits of the sodium-potassium ATPase: differential expression of .alpha. and .beta. subunits in rat tissue membranesBiochemistry, 1989
- Tissue distribution of mRNAs encoding the α isoforms and β subunit of rat Na+,K+-ATPaseBiochemical and Biophysical Research Communications, 1987
- Biochemical characterization of plasma membrane isolated from human skeletal muscleFEBS Letters, 1985
- Effect of streptozotocin‐induced diabetes upon intracellular sodium in rat skeletal muscleFEBS Letters, 1979
- A rapid and sensitive method for the quantitation of microgram quantities of protein utilizing the principle of protein-dye bindingAnalytical Biochemistry, 1976
- Cleavage of Structural Proteins during the Assembly of the Head of Bacteriophage T4Nature, 1970