Functions as a calcium- and DAG-regulated nucleotide exchange factor specifically activating Rap through the exchange of bound GDP for GTP. May also activate other GTPases such as RRAS, RRAS2, NRAS, KRAS but not HRAS. Functions in aggregation of platelets and adhesion of T-lymphocytes and neutrophils probably through inside-out integrin activation. May function in the muscarinic acetylcholine receptor M1/CHRM1 signaling pathway. Isoform 1 and isoform 2 are differently regulated by calcium and DAG. Forms a signaling complex with RAP1 and BRAF (By similarity). Interacts with RAP1. Interacts with F-actin. Found both in the cytosol and associated with membranes. Isoform 2 mainly localizes to the cell membrane. Enriched at juxtamembrane areas and membrane ruffles through association with F-actin. Localizes to the cell bodies and axons of striatal neurons (By similarity). Detected in platelets, neutrophils and T lymphocytes (at protein level). Expressed in brain where it is enriched in the striatum. Also expressed in the hematopoietic system. Detected in heart, brain, lung, placenta, liver, skeletal muscle and kidney. Expressed in fetal brain, lung, liver and kidney. The N-terminal Ras-GEF domain mediates association with F-actin. Isoform 2 is palmitoylated and myristoylated. The disease is caused by variants affecting the gene represented in this entry. The corresponding protein is not undetectable. Belongs to the RASGRP family. Defects in RASGRP2 were initially thought (PubMed:17576779) to be the cause of leukocyte adhesion deficiency type 3 (LAD3), a syndrome characterized by recurrent bacterial infections and major bleeding disorders. However, it was later shown (PubMed:19064721, PubMed:19234463 and PubMed:19234460) that it is not the case and that LAD3 is caused by defects in FERMT3 gene. RASGRP2 mutation db