Figure 5: Stk38 inhibits MEKK2 expression.

(a) Luciferase assay of activation of Elk1 in HEK293T cells transfected with 50 ng MEKK2-expressing plasmid, 100 ng Elk1 luciferase reporter plasmid, 2.5 ng pTK-Renilla-luciferase and 0, 100 or 200 ng of Stk38-expressing plasmid. Luciferase activity was measured and normalized by Renilla luciferase activity. Data are shown as mean±s.d. (n=4) of one typical experiment (**P<0.01, Student’s t-test). Similar results were obtained in three independent experiments. (b) Immunoblot assay of MEKK2 expression in HEK293T cells transfected with MEKK2-expressing plasmid and increased amount of Stk38-expressing plasmid. Similar results were obtained in three independent experiments. (c) Immunoblot assay of MEKK2 expression in wild-type (WT) and Stk38-deficient macrophages. Similar results were obtained in three independent experiments. (d) Schematic diagram of wild-type and mutant Stk38. Numbers in parentheses indicate amino acids included in the constructs. (e) Immunoblot (IB) assay of MEKK2 expression in HEK293 cells transfected with MEKK2-expressing plasmid together with wild-type or mutant Stk38-expressing plasmids. Similar results were obtained in three independent experiments.