PMID: 22330088

Authors:

Mills SJ, Persson C, Cozier G, Thomas MP, Tresaugues L, Erneux C, Riley AM, Nordlund P, Potter BV

Title:

A Synthetic Polyphosphoinositide Headgroup Surrogate in Complex with SHIP2 Provides a Rationale for Drug Discovery.

Journal:

ACS Chem Biol. 2012 May 18;7(5):822-8. Epub 2012 Feb 27.

Abstract:

Phosphoinositides regulate many cellular processes, and cellular levels are controlled by kinases and phosphatases. SHIP2 (SH2 (Src homology 2)-domain-containing inositol-phosphatase-2) plays a critical role in phosphoinositide signaling, cleaving the 5-phosphate from phosphatidylinositol 3,4,5-trisphosphate. SHIP2 is thought to be involved in type-2 diabetes and obesity, conditions that could therefore be open to pharmacological modulation of the enzyme. However, rational design of SHIP2 inhibitors has been limited by the absence of a high-resolution structure. Here, we present a 2.1 A resolution crystal structure of the phosphatase domain of SHIP2 bound to the synthetic ligand biphenyl 2,3',4,5',6-pentakisphosphate (BiPh(2,3',4,5',6)P(5)). BiPh(2,3',4,5',6)P(5) is not a SHIP2 substrate but inhibits Ins(1,3,4,5)P(4) hydrolysis with an IC(50) of 24.8 +/- 3.0 muM, (K(m) for Ins(1,3,4,5)P(4) is 215 +/- 28 muM). Molecular dynamics simulations suggest that when BiPh(2,3',4,5',6)P(5) binds to SHIP2, a flexible loop folds over and encloses the ligand. Compounds targeting such a closed conformation might therefore deliver SHIP2-specific drugs.