Figure 2.

Both ERK3 L290P and L290V mutants have increased ability to promote lung cancer cell migration and invasion. (a) Western blot analysis of ERK3 and ERK3 mutants’ expression in H1299 cells transfected with an empty vector (EV), ERK3 wild type (ERK3), ERK3 L290P or ERK3 L290V plasmids as indicated. β-actin was used as a loading control. (b) The effect of L290P/V mutations on ERK3’s role in H1299 cell migration was analyzed by two-chamber transwell migration assay of H1299 cells transfected with an EV, wild type ERK3 or each of the ERK3 L290 mutants. Representative images are shown at the bottom. Quantitative results are presented as number of migrated cells per field. Values in bar graph represent mean ± S.D. of 3 separate experiments. *P < 0.05 by Student’s t-test. (c) Two-chamber transwell invasion assay of H1299 cells transfected with the indicated plasmids. Representative images are shown at the bottom. Quantitative results are presented as number of invaded cells per field. Values in bar graph represent mean ± S.D. of 3 separate experiments. *P < 0.05 by Student’s t-test. (d) Western blot analysis of ERK3 and ERK3 mutants’ expression in A549 cells transduced with lentiviral expression constructs as indicated. Please note that the lower bands in ERK3 blot are endogenous ERK3 proteins and the upper bands are exogenously expressed ERK3 or ERK3 L290P/V mutants that contain 6 Myc tags at the N-terminus. (e) Two-chamber transwell invasion assay of A549 cells with lentiviral transduction of EV, wild type ERK3 or each of the ERK3 L290 mutants. Representative images are shown at the bottom. Quantitative results are presented as number of invaded cells per field. Values in bar graph represent mean ± S.D. of 3 separate experiments. *P < 0.05 by Student’s t-test.