Rat GRB2 Related Adaptor Protein 2 (GRAP2) Protein

Background

GRAP2, also known as GADS (GRB2-related adaptor downstream of SHC), is a hematopoietic-specific adaptor protein that serves as a key mediator in immune cell activation. It contains SH2 and SH3 domains, enabling interactions with critical proteins like LAT (linker for activation of T cells), SLP-76, and SOS to form multiprotein complexes (signalosomes). These complexes activate downstream signaling pathways, including NF-κB, MAPK/ERK, and actin cytoskeletal rearrangements required for immune synapse formation. GRAP2 is essential for T-cell receptor (TCR) and B-cell receptor (BCR) signaling, supporting processes like lymphocyte proliferation, antigen receptor-mediated activation, and cytokine production. GRAP2 is required for immune cell polarization, adhesion, and migration, ensuring effective adaptive immune responses. Dysregulation contributes to immune deficiencies, autoimmune diseases, and hematopoietic disorders, affecting lymphocyte development and function. Knockout studies reveal impaired T-cell development, antigen signaling defects, and reduced cytokine responses, highlighting its critical role in adaptive immunity and lymphocyte signaling.