Negatively regulates Ras signaling pathways and downstream activation of MAP kinases (, ). Recruits and translocates NF1 to the cell membrane, thereby enabling NF1-dependent hydrolysis of active GTP-bound Ras to inactive GDP-bound Ras . Inhibits fibroblast growth factor (FGF)-induced retinal lens fiber differentiation, probably by inhibiting FGF-mediated phosphorylation of ERK1/2 (By similarity). Inhibits TGFB-induced epithelial-to-mesenchymal transition in lens epithelial cells (By similarity).
Subcellular locations: Cell membrane, Cytoplasmic vesicle, Secretory vesicle membrane, Cytoplasm
Detected in the cytoplasm of the stratum spinosum cells, where it is associated with cytoplasmic vesicles that are supposed to be secretory granules.
Expressed in liver, skin, small intestine, salivary gland and prostate.