<i>dPdxk</i> mutants are defective in the insulin signaling pathway.

<p>(A) Simplified representation of the insulin-signaling pathway; see text for description. (B) Western blotting showing that <i>dPdxk¹</i> mutants contain normal levels of DILP2. (C) Akt phosphorylation levels in wild type (wt) and <i>dPdxk¹</i> mutant brains with or without insulin stimulation; P-Akt is the phosphorylated (Ser 505) Akt protein recognized by phospho-specific antibody; Pan-Akt is the is total Akt protein recognized by a specific antibody; Gio is a <i>Drososphila</i> Phosphatidylinositol transfer protein used as loading control (see <a href="http://www.plosgenetics.org/article/info:doi/10.1371/journal.pgen.1004199#s4" target="_blank">Methods</a>). (D) Quantification of the Akt phosphorylation levels. The intensity of the P-Akt bands was normalized to both total Akt and the Gio loading control. The columns are the means ±SE of 12 independent samples of 20 brains from 3 independent experiments (see <a href="http://www.plosgenetics.org/article/info:doi/10.1371/journal.pgen.1004199#s4" target="_blank">Methods</a>); the wild type pAkt/panAkt/Gio ratio has been arbitrarily set equal to 1. *, significantly different with p<0.05 in the Student t test. A short-exposure version of the blot from insulin-stimulated brains (<a href="http://www.plosgenetics.org/article/info:doi/10.1371/journal.pgen.1004199#pgen.1004199.s002" target="_blank">Figure S2</a>) provides visual evidence for a reduced P-Akt level in <i>dPdxk</i> mutants.