Figure 1

MKL1 is upregulated during temperature-switched cell cycle arrest in MPC5 cells. A) MPC5 cells were cultured at the permissive temperature of 33°C or the nonpermissive temperature of 37°C. At the indicated time points, cell growth was measured using a CCK-8 assay. **p < 0.01 compared with the control (one-way ANOVA followed by Tukey’s HSD test). B) MPC5 cells were shifted from 33°C to 37°C and cultured for the indicated times. Cell proliferation was measured by immunofluorescence analysis of EdU incorporation. Scale bars, 25 μm. C) The percentage of proliferating cells was calculated as EdU-positive cells/Hoechst-stained cells × 100%. **p < 0.01 compared with the control (one-way ANOVA followed by Tukey’s HSD test). D) MPC5 cells were shifted from 33°C to 37°C and cultured for the indicated times. The mRNA expression levels of myocardin, MKL1 and MKL2 were verified by qPCR. GAPDH was used to normalize expression levels. *p < 0.05 compared with the control (one-way ANOVA followed by Tukey’s HSD test). E) MPC5 cells were shifted from 33°C to 37°C and cultured for the indicated times. Protein expression levels of MKL1 were examined by western blotting. Actin was used to normalize MKL1 levels.