GTPase Activating Protein SH3 Domain Binding Protein 1 (G3BP1)

G3BP contains an acid-rich amino acid domain between amino acids 144 and 221, followed by 2 consensus RNA-binding motifs and several C-terminal arg/gly-rich boxes, which are also implicated in RNA binding. Northern blot analysis detected a 3.3-kb G3BP transcript in all fetal and adult tissues examined, with prominent expression in adult skeletal muscle. Immunofluorescence analysis of several mammalian cell lines localized G3BP within the cytoplasm. The staining intensity varied between cells, but the intensity and localization were unaltered under various experimental conditions. G3bp purified from Chinese hamster lung fibroblasts and recombinant G3BP expressed in insect cells both showed apparent molecular masses of 68 kD.