Dual Adaptor Of Phosphotyrosine And 3-Phosphoinositides (DAPP1)

Adaptor proteins are a link between 'upstream' cell surface receptors and nonreceptor protein tyrosine kinases and 'downstream' molecules such as phosphatidylinositol (PtdIns) 3-kinase (PI3K).Sequence analysis predicted that the 280-amino acid protein contains a potential myristoylation site (a glycine after the N-terminal methionine), an N-terminal SH2 domain, and a C-terminal PH domain with a PtdIns-interacting motif. The authors noted that APS also has an SH2 domain and a PH domain but at opposite termini of the protein. PCR of cDNA libraries and Northern blot analysis revealed ubiquitous expression of 2.7-kb transcripts, with highest levels in placenta and lung. A protein-lipid overlay analysis indicated that the PH domain of DAPP1 interacts with physiologic enantiomers of PtdIns.