Figure 1.

Both ERK3 L290P and ERK3 L290V mutants have increased ability to promote HeLa cell migration as compared to wild type ERK3. (a) Western blot analysis of ERK3 and ERK3 mutants’ expression in HeLa cells transfected with either a pSG5 empty vector, wild type ERK3 (ERK3 WT), or each ERK3 L290 mutant as indicated. β-actin was used as a loading control. (b) The effect of L290P/V mutations on ERK3’s role in HeLa cell migration. HeLa cells were transfected with each different pSG5 plasmid as indicated. Two days post-transfection, cell migration was analyzed using a two-chamber transwell system. Migrated cells were stained with crystal violet, photographed and counted under a microscope at 50X magnifications. Quantitative results are presented as the number of migrated cells per field. Values in the bar graph represent mean ± S.D. of 3 separate experiments. *P < 0.05 by Student’s t-test. Representative images are shown at the bottom. (c) The effect of L290P/V mutations on ERK3’s role in HeLa cell proliferation. HeLa cells were transfected with the following plasmids: empty vector (EV), ERK3 WT, ERK3 L290P or ERK3 L290V. Cell growth at different time points (days) was determined by MTS proliferation assay and expressed as OD₄₉₀. Values represent mean ± S.D. of 3 separate experiments. Statistical analysis was conducted by student’s t-test. N.S.: no significance.