Growth Arrest Specific Protein 1 (GAS1)

Growth arrest-specific 1 plays a role in growth suppression. GAS1 blocks entry to S phase and prevents cycling of normal and transformed cells. Gas1 is a putative tumor suppressor gene.The deduced 345-amino acid protein contains 2 putative transmembrane domains, an RGD consensus recognition sequence, and 1 potential N-glycosylation site. The human and mouse proteins share 82% sequence identity. In vitro translation resulted in a protein with an apparent molecular mass of about 45 kD. the GAS1 protein undergoes cotranslational modifications within the endoplasmic reticulum. Modifications consist of signal peptide cleavage, N-linked glycosylation, and glycosylphosphatidylinositol anchor addition. Immunoelectron microscopy of resting mouse fibroblasts found Gas1 randomly distributed over the outer leaflet of the plasma membrane.