The function of GADD34 is a recovery from a shutoff of protein synthesis induced by ER stress: elucidation by GADD34-deficient mice.

SPECIFIC AIMSGADD34 is a member of the protein family whose expression is up-regulated by growth arrest and DNA damage, but its function has not yet been elucidated in vivo. We tried to find the function of GADD34 by constructing GADD34-deficient mice.PRINCIPAL FINDINGS1. GADD34 is highly expressed at the fetal stage and in adult mouse organsAt the fetal stage of C57BL/6CR mice, GADD34 mRNA expression was detected on embryonic day 8.5 (E8.5), E9.5, E12.5 (especially strong), E14.5, and E18.5. Almost no expression was detected on E10.5, E11.5, and E13.5. The distribution of GADD34 was ubiquitously expressed on E12.5; it is expressed at high levels in the brain, spinal cord, tongue, lung, and genital tubercle. In adult mice, GADD34 expression was strong in the spleen and lung, moderate in the thymus and muscle, weak in the brain, and almost undetectable in the other organs examined (liver, small intestine, testis, and ovary).2. GADD34 knockout mice show normal development and normal fertilityTo elucidate th...