Figure 4: Specificity of PP2Ce Activity to PLN Thr-17 Phosphorylation

(A) Immunoblot of PP2Ce, GFP, and PLN phosphorylation (Ser-16 and Thr-17) in NRVM expressing GFP or PP2Ce wild-type or PP2Ce phosphatase dead mutant (D320A) following 1 μmol/l isoproterenol treatment at different time points as indicated. (B) ISO-induced PP2Ce expression and PLN phosphorylation in NRVM-expressing PP2Ce truncation mutant (⊿1–57), which has lost ER targeting capacity (28,29). (C) PP2Ce–GST fusion protein was incubated with PLN isolated from NRVM with or without ISO treatment, followed by immunoblot for total and phosphorylation levels of PLN at Ser-16 and Thr-17. (D) Coimmunoprecipitation of PP2Ce and PLN in mouse heart using PP2Ce TG and PP2Ce KO as positive and negative control, respectively. ISO = isoproterenol; TG = transgenic; other abbreviations as in Figures 2 and 3.



Elsevier user license