This gene encodes a protein that binds inositol 1,3,4,5-tetrakisphosphate and stimulates the GTPase activity of Ras p21. This protein functions as a negative regulator of the Ras signalling pathway. It is an 829-amino acid protein that binds phospholipids in both a calcium-dependent and -independent
manner.It is localized to the cell membrane via a pleckstrin homology (PH) domain in the C-terminal region. The PH domains of GAP1-InsP4 BP are essential for membrane targeting via binding of specific phospholipids.
