Proline Rich Akt Substrate (PRAS40) is a 40 kDa substrate of Akt. Akt and PRAS40 can be found in the phosphoinositide 3 kinase (PI3K) pathway, which plays a role in glucose uptake, cell growth, and apoptosis inhibition. PRAS40 is a 14-3-3 binding protein that reacts with insulin, but whose precise function is not yet known. It may bind SH3 and WW domain containing proteins resulting in a change of function. Activated Akt phosphorylates PRAS40 on threonine 246. Mutation of PRAS40 threonine 246 has been shown to be apoptotic.