Fig. 3

Vitronectin stimulates Fos-related antigen 1 (FRA-1) phosphorylation and FRA-1 transcriptional targets. a Immunoblot analyses of selected integrins in BRC cell lines and mammary tumor explants. b Immunoblot analyses of FRA-1 phosphorylation in BRC-31 cells plated on uncoated (PL), or dishes pre-coated with vitronectin (VN), fibronectin (FN) or laminin (LN). c The level of phosphorylation of FRA-1 was quantified relative to the loading control α-Tubulin. The data from three independent lysates are plotted normalized to the level of phosphorylation on uncoated dishes, *P < 0.01. d Immunoblot analyses of BRC-31 cells transfected with siRNAs against mitogen-activated protein kinase (mapk1) (extracellular signal-related kinase 2 (ERK2) knockdown (KD)), mapk3 (ERK1 KD) or scrambled control (Scr), which were subsequently plated on vitronectin-coated cell culture dishes for 30 minutes. e Gene expression analysis of FRA-1 regulated transcriptional targets, chloride channel accessory 2 (clca2), adhesion G protein-coupled receptor G6 (adgrg6), C-X-C motif chemokine ligand 8 (cxcl8) and C-C motif chemokine ligand 5 (ccl5) following plating on uncoated or extracellular matrix (ECM)-coated cell culture dishes. Data are normalized to the expression from cells plated on uncoated dishes. Error bars are the standard error of the mean. *P < 0.03. Blots (a, b, d) are representative of at least three independent sets of lysates and α-Tubulin serves as a loading control