GHSR constitutive activity fails to reduce CaVβ density on plasma membrane in the absence of CaVα1. (A) Confocal images of tsA201 cells co-transfected with CaVβ2a-eGFP, CaVα2δ1, plasma membrane marker (PM-marker), endoplasmic reticulum-marker (ER-marker) and GHSR (+GHSR, n=9) or of controls transfected with empty plasmid (-GHSR, n=9). (B) Confocal images of tsA201 cells co-transfected with CaVβ3-eGFP, CaVα2δ1, plasma membrane marker (PM-marker), endoplasmic reticulum-marker (ER-marker) and GHSR (+GHSR, n=7) or of controls transfected with empty plasmid (-GHSR, n=8). Bar graphs show the colocalization of green signal from CaVβ3-eGFP or CaVβ2a-eGFP with blue signal (from PM-marker) or with red signal (from ER-marker). Scale bars: 10 µm. Error bars represent mean±s.e.m., individual points represent each quantified cell. Student's t-test (A) and Mann–Whitney test (B).