The Vacuolar-Type H⁺-ATPase in Ovine Rumen Epithelium is Regulated by Metabolic Signals

Figure 4

Immunolocalization of Na⁺/K⁺-ATPase 𝛼-subunit (A, green) and of vH⁺-ATPase B subunit (B, green) in ovine REC. Monoclonal mouse antibodies against sheep Na⁺/K⁺-ATPase 𝛼-subunit or yeast vH⁺-ATPase 60 kDa subunit, and an Alexa fluor 488 conjugated secondary antibody were used. The nuclei are counterstained with DAPI (blue). Compared to control conditions (Ba) glucose substitution with 2-DOG (Bb) and complete MI (glucose substitution with 2-DOG and antimycin A application; Bc) induced loss of membrane staining and appearance of diffuse, cytosolic staining of vH⁺-ATPase B subunits. In contrast, the Na⁺/K⁺-ATPase was always localized to the cell membrane and not influenced by metabolic inhibition (A a–c).