Fig. 3
From: Vimentin dephosphorylation at ser-56 is regulated by type 1 protein phosphatase in smooth muscle
Knockdown of PP1 increases vimentin phosphorylation at Ser-56 and contraction in smooth muscle. a Mouse tracheal rings were transduced with lentiviruses encoding control shRNA or PP1 shRNA. These tissues were then incubated in the serum-free medium for 4 days. Immunoblot analysis was used to assess protein expression in tissues. Ctrl, control shRNA; PP1, PP1shRNA. *Significantly lower protein ratios of PP1/actin in tissues transduced with virus encoding PP1 shRNA than in tissues expressing control shRNA (p < 0.05). Data represent mean ± SE (n = 5). b Tracheal rings treated with control or PP1 shRNA were stimulated with ACh (10−4 M, 5 min), or left unstimulated. Vimentin phosphorylation at Ser-56 was evaluated by immunoblotting. Vimentin phosphorylation is normalized to unstimulated rings treated with control shRNA. Data are mean values of eight independent experiments. Error bars indicate SE (*, p < 0.05). c Contraction of tracheal rings was evaluated, after which they were transduced with lentiviruses as described above. Contractile responses were compared before and after incubation. Contraction is normalized to the contraction of rings treated with control shRNA in response to stimulation with 10−3 M ACh. *Significantly higher contraction of rings treated with PP1 shRNA as compared to tissues infected with viruses encoding control shRNA (p < 0.05). Data are mean ± SE (n = 6)