GRB2-related adaptor protein (GRAP)

GRB2-related adaptor protein (GRAP) is a cytoplasmic signaling adaptor belonging to the GRB2/Sem5/Drk protein family. It contains a central SH2 domain flanked by two SH3 domains, enabling it to link receptor and cytoplasmic tyrosine kinases, such as stem cell factor and erythropoietin receptors, to downstream effectors like SOS1 and the Ras signaling pathway[4][9]. GRAP is primarily expressed in hematopoietic tissues but also has functions in the inner ear, where it is involved in auditory signaling. Genetic variants in GRAP are associated with autosomal recessive deafness (DFNB114)[4][9]. It plays a non-enzymatic but crucial scaffolding role in multiple cell signaling processes. Its role is distinct from GRAP2/GADS and GRB2, though all are adapter molecules with related domain architecture and similar functions in cellular signaling[3][4][5][7]. The abbreviation "DFNB114" relates specifically to the phenotypic presentation (deafness) rather than the canonical molecular nomenclature[4]. There is no evidence from current results that GRAP is a direct drug target or that any approved drugs currently interact with or inhibit/activate this protein.

Other names

GRB2-related adapter proteinDFNB114growth factor receptor-bound protein 2-related adaptor proteinGRAP