GRB2 Related Adaptor Protein (GRAP) Antibody

Background

GRAP is an adaptor protein similar to GRB2, containing SH2 and SH3 domains that mediate protein-protein interactions between receptor tyrosine kinases and intracellular signaling molecules. It is primarily expressed in hematopoietic and immune cells, where it plays a critical role in T-cell receptor (TCR) and cytokine receptor signaling pathways, including MAPK/ERK, JNK, and calcium mobilization cascades. GRAP functions as a scaffold protein, recruiting signaling molecules like SOS, PLCγ, and SHC to facilitate pathways that regulate cell proliferation, survival, and differentiation. It supports immune cell activation, lymphocyte development, and adaptive immune responses. Dysregulation of GRAP impairs immune signaling, leading to defects in T-cell activation, cytokine production, and immune homeostasis. It is particularly important in balancing immune responses to prevent overactivation or immunodeficiency. Knockout studies emphasize its role in TCR signaling, showing defects in T-cell proliferation and response to antigenic stimulation.