KEPI plays a negative role in the repression that accompanies translational inhibition guided by the uORF element of human CHOP transcript during stress response

•KEPI, known as a PP1 inhibitor, was down-regulate during ER stress.•KEPI induces ATF4 and CHOP translation dependent on the increase of p-eIF2α.•During stress, overexpression of KEPI could reduce huORFchop-tag mRNA translation.•KEPI plays a negative role in uORFchop–mediated translation during ER stress.