Figure 2. Knockdown of ESCRT Components Leads to a Persistence in SMAD2 Phosphorylation upon TGF-β Treatment.
(A–D) HaCaT cells were transfected with non-targeting (NT) control siRNAs or siRNAs targeting VPS28 (A), UBAP1 (B), PTPN23 (C), or VPS4B (D)and stimulated with TGF-β for the times indicated. Levels of PSMAD2, SMAD2/3, TGFBR1, TGFBR2, and tubulin as a loading control were assayed by western blot. Quantifications are the normalized average ± SD of three independent experiments. *p < 0.05. The extent of knockdown was assessed by qPCR, and the normalized average ± SD from the same three independent experiments is shown bottom right.