FIG. 1.

GC expression differs between oxidative and glycolytic skeletal muscles and GC localizes to membranes of the cis-Golgi complex. (A) Quantitation of Western blots of α1GC subunit (GC1) expression in WT glycolytic (gastrocnemius and tibialis anterior) and oxidative (soleus and diaphragm) skeletal muscles from 3-month-old mice (B) Quantitation of Western blots of β1GC subunit expression in gas, TA, sol, and dia skeletal muscles from 3-month-old WT mice. (C) Quantitation of Western blots of α2GC subunit (GC2) expression in glycolytic and oxidative skeletal muscles from 2-month-old WT mice. In (A–C), expression was normalized to mean gastrocnemius GC subunit expression. n = 7 for all groups. **p < 0.01, ***p < 0.001, and ****p < 0.0001 by one-way ANOVA with Tukey's multiple comparison test. (D) Representative confocal micrographs showing colocalization (right panel) of the cis-Golgi complex marker, GM130 (left panel), and the β1GC subunit (middle panel) in a WT gastrocnemius myofiber. (E) Representative confocal micrographs of α1GC^−/− gastrocnemius myofiber showing normal GM130 labeling (left panel), but reduced cis-Golgi β1GC labeling (middle panel). For (D, E), insets show a magnified view of Golgi labeling with n ≥ 6 for WT and α1GC^−/− groups. (F) Representative Western blots of α1GC and β1GC expression in gas, TA, sol, and dia from WT and α1GC^−/− mice. (G) Quantitation of Western blots of β1GC expression in α1GC^−/− muscles. β1GC expression is expressed as mean percentage of WT. For (F, G), n = 7 for both groups. ****p < 0.0001 by Student's unpaired t-test comparison of mean β1GC expression between WT and α1GC^−/− muscles. GC, soluble guanylate cyclase; Gas, gastrocnemius; TA, tibialis anterior; Sol, soleus; Dia, diaphragm; WT, wild-type. To see this illustration in color, the reader is referred to the web version of this article at www.liebertpub.com/ars