This family is the N-terminus of GTSE1 proteins. GTSE-1 (G2 and S phase-expressed-1) protein is specifically expressed during S and G2 phases of the cell cycle. It is mainly localised to the microtubules and when overexpressed delays the G2 to M transition. the full protein negatively regulates p53 transactivation function, protein levels, and p53-dependent apoptosis. This domain family is found in eukaryotes, and is approximately 140 amino acids in length. There is a conserved FDFD sequence motif.

1: The cell cycle-regulated protein human GTSE-1 controls DNA damage-induced apoptosis by affecting p53 function. Monte M, Benetti R, Buscemi G, Sandy P, Del Sal G, Schneider C; J Biol Chem. 2003;278:30356-30364. PMID:12750368

2: Polo-like kinase 1 phosphorylation of G2 and S-phase-expressed 1 protein is essential for p53 inactivation during G2 checkpoint recovery. Liu XS, Li H, Song B, Liu X; EMBO Rep. 2010;11:626-632. PMID:20577264