G1-To-S-Phase Transition Protein 2 (GSPT2)

GSPT2 is closely related to GSPT1, a GTP-binding protein that plays an essential role at the G1- to S-phase transition of the cell cycle in yeast and human cells. GSPT1 is a positive regulator of translational accuracy and, in a binary complex with eRF1, functions as a polypeptide chain release factor.

The deduced 632-amino acid protein has a 2-domain structure with a unique N-terminal region and a conserved C-terminal eukaryotic elongation factor 1-alpha-like domain. Mouse Gspt2 shares 81% identity with human GSPT1. RT-PCR analysis revealed expression in all tissues examined, with relative abundance in brain. In contrast to Gspt1, Gspt2 expression in Swiss 3T3 cells did not fluctuate with the cell cycle or upon phorbol ester stimulation.