Na,K-ATPase in skeletal muscle: two populations of β-spectrin control localization in the sarcolemma but not partitioning between the sarcolemma and the transverse tubules

Abstract

There was an error published in J. Cell Sci. 114, 751-762.In Fig. 1, the authors mistakenly included several panels taken from quadriceps muscle that had been used in a previous publication, rather than original images of the extensor digitorum longus. The corrected figure is shown below.

Tissue-specific Role of the Na,K-ATPase α2 Isozyme in Skeletal Muscle

“…4). Control muscle fibers express the ␣1 isoform mainly on the surface sarcolemma, as reported (28). sk␣2 Ϫ/Ϫ muscle fibers show enhanced ␣1 expression on the surface sarcolemma, consistent with the increased ␣1 protein detected on Western blot.…”

“…Within muscle cells (fibers), it is expressed on the transverse tubule membrane (Fig. 3, A and D); in discreet regions of the surface sarcolemma, including the muscle end plate, caveolae, and costameres (10,28,36); and on the sheath surrounding the muscle spindle (not shown). In non-muscle cells within the tissue (Fig.…”

The cardiac glycoside binding site on the Na,K-ATPase α2 isoform plays a role in the dynamic regulation of active transport in skeletal muscle

“…This result indicates that the cardiac glycoside affinity of the ␣2 isoform is not required for maintaining bulk interstitial K ϩ homeostasis during intense muscle contraction lasting tens of minutes. This measurement cannot exclude the possibility that the local [K] change in the transverse tubules, where the ␣2 isoform is localized (28), may differ between genotypes or that earlier, rapid changes may have been missed.…”

Na+-K+-ATPase in rat skeletal muscle: muscle fiber-specific differences in exercise-induced changes in ion affinity and maximal activity

“…The ␣1 and ␣2 isoforms are found in all muscle fiber types; however, they exhibit different cellular localization patterns. Both the ␣1 and ␣2 isoforms are present in the sarcolemmal fraction, but only the ␣2 isoform is present in the T-tubules (29). The ␤1 isoform is mainly found in oxidative fibers, whereas the ␤2 isoform is found in glycolytic fibers (9,28).…”