DAPP1 Gene - Dual Adaptor of Phosphotyrosine and 3-Phosphoinositides | Function, Mutations & Disease

DAPP1 (dual adaptor of phosphotyrosine and 3-phosphoinositides), also known as BCAP, encodes a protein that contains an N-terminal pleckstrin homology (PH) domain and a C-terminal Src homology 2 (SH2) domain. It functions as an adaptor in B-cell receptor (BCR) signaling, linking the BCR to phosphatidylinositol 3-kinase (PI3K) activation. The PH domain binds phosphatidylinositol (3,4,5)-trisphosphate (PIP3), recruiting the protein to the plasma membrane, while the SH2 domain interacts with phosphorylated tyrosine residues on other signaling proteins. DAPP1 is involved in B-cell development, activation, and survival.

Tissue Expression

Cell Line Expression

Hotspot Mutations

Mutation functional classification

• B cell receptor signaling pathway (Reactome: R-HSA-983705)

• PI3K/AKT signaling (Reactome: R-HSA-1257604)

• Fcgamma receptor (FCGR) dependent phagocytosis (Reactome: R-HSA-2029480)

DAPP1 is a 280-amino acid adaptor protein with a PH domain at the N-terminus and an SH2 domain at the C-terminus. The PH domain specifically binds PIP3, enabling membrane recruitment upon PI3K activation. The SH2 domain binds phosphotyrosine motifs, facilitating interactions with upstream kinases such as SYK and BTK. DAPP1 is essential for optimal BCR-mediated PI3K activation, B-cell proliferation, and survival. It is predominantly expressed in hematopoietic tissues, especially B cells.