To examine the function of GADD34, we used the yeast two-hybrid system to clone the protein that interacts with the murine GADD34 gene product. We utilized, as bait, the product of the GADD34 cDNA deletions including the PEST region and the gamma(1)34.5 domain. One of the cDNAs cloned encoded murine Translin which is known to bind to the DNA sequence detected in the DNA translocation. The interaction between GADD34 and Translin was also confirmed by an in vitro binding assay and in vivo two-hybrid analysis in NIH 3T3 cells. Although GADD34 expression was significantly elevated with methyl methanesulfonate treatment, we could not detect the induction of Translin mRNA.