DAPP1: a dual adaptor for phosphotyrosine and 3-phosphoinositides

We have identified a novel 280 amino acid protein which contains a putative myristoylation site at its N-terminus followed by an Src homology (SH2) do main and a pleckstrin homology (PH) domain at its C-terminus. It has been t ermed dual adaptor for phosphotyrosine: and 3-phosphoinositides (DAPP1). DA PP1 is widely expressed and exhibits high-affinity interactions with PtdIns (3,4,5)P-3 and PtdIns(3,4)P-2, but not with other phospholipids tested. The se observations predict that DAPP1 will interact with both tyrosine phospho rylated proteins and 3-phosphoinositides and may therefore play a role in r egulating the location and/or activity of such proteins(s) in response to a gonists that elevate PtdIns(3,4,5)P-3 and PtdIns(3,4)P-2.