Schematic representation of Pyk2 phosphorylation triggered by Src.

<p>In the inactive state, Pyk2 is in an unphosphorylated state. Upon integrin ligand binding, Src phosphorylates Y402, creating a binding site for the SH2-domain of Src, and enabling further phosphorylation of Pyk2 by Src, including at site Y579 (and likely at Y580, although not studied here). As shown by others [<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0149231#pone.0149231.ref021" target="_blank">21</a>,<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0149231#pone.0149231.ref022" target="_blank">22</a>] phosphorylated and activated Pyk2 dimerizes or oligomerizes with itself, leading to further phosphorylation of Pyk2 via auto/trans-phosphorylation.