SHIPs ahoy

In 1996 three groups independently cloned a hemopoietic specific, are homol ogy 2-containing inositol 5'-phosphatase which, based on its structure, was called SHIP. More recently, a second more widely expressed SHIP-like prote in has been cloned and called SHIP2. Both specifically hydrolyze phosphatid ylinositol-3,4,5-trisphosphate and inositol 1,3,4,5-tetrakisphosphate in vi tro. Moreover, SHIP has been shown in vivo to be the primary enzyme respons ible for breaking down phosphatidylinositol-3,4,5-trisphosphate to phosphat idylinositol-3,4-bisphosphate in normal mast cells and, as a result, limits normal and prevents inappropriate mast cell degranulation. Because of thei r ability to break down phosphatidyrinositol-3,4,5-trisphosphate the SHIPs have the potential to regulate many, if not all, phosphatidylinositol-3-kin ase induced events including, proliferation, differentiation, apoptosis, en d cell activation, cell movement and adhesion and will thus likely be the s ubject of intensive research over the next few years. (C) 1999 Elsevier Sci ence Ltd. All rights reserved.