Fig. 8.

Jagged1 deficiency impairs Ca²⁺ sensitization. A: representative immunoblots displaying impaired KCl-induced phosphorylation (P) of myosin phosphatase-targeting subunit 1 (MYPT1; residues Thr⁶⁹⁶ and Thr⁸⁵³) in Jagged1-deficient [tamoxifen (TM)-treated (+TM) smooth muscle myosin heavy chain-Cre^ERT2 (SMMHC-Cre^ERT2)/Jagged1 flox/flox (Jag1^f/f)] aortic smooth muscle cells (SMCs). Cultured SMCs were exposed to 60 mM KCl for 0–30 min (0–30′). Data represent means ± SE (n = 3) and were analyzed using one-way ANOVA with Tukey’s post hoc test, *P < 0.01 and **P < 0.05 (vs. 0 min). KCl stim, KCl stimulation; −TM, sunflower oil control. B: Jagged1-stimulated MYPT1 phosphorylation was Rho kinase dependent. A10 aortic SMCs were treated for 5 h with DMSO or the Rho kinase inhibitor Y27632 followed by fixed-ligand [Fc, delta-like protein-4 (Dll4), or Jagged1 (J1)] stimulation for 24 h. Representative immunoblots are shown. Data represent means ± SE (n = 3) and were analyzed using one-way ANOVA with a Tukey’s post hoc test, *P < 0.05, **P < 0.01, and ***P < 0.001.