Anti-phospho RasGRP2 (Ser554) from rabbit

RAS guanyl-releasing protein 2 (UniProt: Q9QUG9; also known as Calcium and DAG-regulated guanine nucleotide exchange factor I, RasGRP2, CalDAG-GEFI, F25B3.3 kinase-like protein) is encoded by the Rasgrp2 gene (Gene ID: 19395) in murine species. RasGRP proteins are considered as activators of Ras and other related small GTPases by virtue of functioning as guanine nucleotide exchange factors (GEFs). RasGRP-1 through -4 share many structural domains, however, they display subtle differences between each of the different family members. They are expressed in distinct patterns, such as in different cells of the hematopoietic system and in the brain. RasGRP2's expression is restricted to platelets and their precursors, megakaryocytes, and neutrophils. RasGRP2 functions as a calcium- and DAG-regulated nucleotide exchange factor specifically activating Rap through the exchange of bound GDP for GTP. It may also activate other GTPases such as RRAS, RRAS2, NRAS, KRAS, but not HRAS. It is also reported to function in aggregation of platelets and adhesion of T-lymphocytes and neutrophils, probably through inside-out integrin activation. RaGRP2 is found both in the cytosol and associated with membranes. It is shown to be enriched at juxtamembrane areas and membrane ruffles. Three isoforms of RasGRP2 have been reported that are generated by alternative splicing. It contains two EF-hand domains, one N-terminal Ras-GEF domain, one phorbol-ester/DAG-type zinc finger domain, and one Ras-GEF domain. RasGRP2 deficient animals exhibit bleeding problems due to defects in platelets aggregation and degranulation. (Ref.: Olga Ksionda, O et al. (2013). Front Biol (Beijing). 8(5): 508 532).