FIG. 2.

GC is targeted to the neuromuscular synapse in muscle cells and expressed in muscle-associated microvasculature. (A) Representative confocal micrographs showing that α2GC subunit is not localized to the cis-Golgi complex marked by GM130, but is expressed in blood vessels closely associated with muscle cells in the tibialis anterior. Striated staining was also observed potentially representing another GC2 compartment. (B) Representative confocal micrographs showing that β1GC subunit localizes to the cis-Golgi complex marked by GM130 in myofibers and to muscle-associated blood vessels. (C) Representative confocal micrographs of a transverse section of gastrocnemius muscles coimmunolabeled with α-bungarotoxin to identify postsynaptic AchRs of the neuromuscular junction (left panel) and anti-β1GC antibodies (middle panel). β1GC was enriched at the neuromuscular junction (right panel) and in blood vessels, but did not localize to the sarcolemma. (D) Representative high-magnification confocal micrographs showing an en face view of the neuromuscular junction labeled with AchR (left panel) from a gastrocnemius myofiber. β1GC (middle panel) colocalized with AchR (right panel), indicating targeting of GC to the neuromuscular synapse. (E) Representative confocal micrographs showing that α1GC subunit is localized to the cis-Golgi complex marked by GM130 and to striations and blood vessels closely associated with individual muscle fibers in the tibialis anterior. For all groups, n ≥ 3. AchR, acetylcholine receptor. To see this illustration in color, the reader is referred to the web version of this article at www.liebertpub.com/ars