Characterization of a murine gene encoding an acidic-basic dipeptide repeat that interacts with GADD34

GADD34 is one of a subset of proteins induced after DNA damage or cell growth arrest. To examine the function of GADD34, we used the yeast two-hybrid system to clone the protein that interacts with murine GADD34. We utilized as bait the partial product of GADD34 cDNA including the PEST region and the gamma(1)34.5. One cDNA clone was almost the same as MuRED, which encodes an acidic-basic dipeptide repeat; we named it G34BP. The interaction between GADD34 and G34BP was also confirmed in the NIH3T3 cells by in vivo two-hybrid analysis. For the binding of two proteins, the PEST region was important, and the C-terminal of G34BP was necessary. G34BP was detected in all the mouse tissues examined. Although GADD34 was significantly elevated with methyl methanesulfonate treatment, G34BP expression was not induced. Overexpression of G34BP in the NIH3T3 cells inhibited the cell growth analyzed by WST1 assay.