Cloning of ARE-containing genes by AU-motif-directed display

A procedure suitable for cloning labile mRNAs that contain AU motifs is pre sented (AU-DD). These motifs are regulatory sequences within the so-called AU-rich elements (AREs) often found in 3' untranslated regions of genes suc h as cytokines, proto-oncogenes, and transcription factors. AU-DD is an AU- motif-directed differential display that permits the identification of ARE- containing genes differentially expressed after cell activation. It has bee n applied to peripheral blood monocytes and a T cell clone to isolate 59 cD NA fragments associated to activation. Fourteen percent of isolated fragmen ts belong to already known genes that certainly are cytokines and transduct ion/transcription factors. The remaining 86% correspond to unknown genes of which 92% have been confirmed to be differentially expressed. These data d emonstrate the efficiency of the system and support the notion that numerou s genes falling into those categories remain unidentified and that they can be cloned by this method. (C) 1998 Academic Press.