VASP is differentially phosphorylated during <i>C</i>. <i>burnetii</i> infection.

<p>THP-1 cells infected for 24 or 96 h and uninfected control cells were harvested and total protein immunoprecipitated with a PKA phospho substrate-specific antibody. (A) Immunoprecipitated proteins were subjected to Coomassie Blue staining and the arrow indicates a ~ 47 kDa protein only in infected cell samples. UI = Uninfected Cells. (B) Schematic of VASP showing five phosphorylation sites (Y39, S157, S239, T278, and S322) and EVH protein-protein interaction domains. PRO = proline rich region. (C) Immunoprecipitated proteins were subjected to immunoblot analysis using antibodies directed against VASP, phosphorylated VASP (S157), or PKA phospho substrates. Lysates were analyzed for β-tubulin to confirm equal protein loading. Agarose bead-bound PKA phospho substrate-specific antibody was eluted, immunoblotted, and probed with anti-IgG antibody to confirm equal amounts of antibody for immunoprecipitations. Densitometry analysis is shown in the graph and represents an average of three independent experiments. Error bars indicate the standard error of the mean. Control = uninfected cells. Increased levels of total and phosphorylated VASP (S157) are present in <i>C</i>. <i>burnetii</i>-infected cells.