REPE - THE DICTYOSTELIUM HOMOLOG OF THE HUMAN XERODERMA-PIGMENTOSUM GROUP-E GENE IS DEVELOPMENTALLY-REGULATED AND CONTAINS A LEUCINE-ZIPPERMOTIF

We have cloned and characterized the Dictyostelium discoideum repE gen e, a homolog of the human xeroderma pigmentosum (XP) group E gene whic h encodes a UV-damaged DNA binding protein, The repE gene maps to chro mosome 4 and it is the first gene identified in Dictyostelium that is homologous to those involved in nucleotide excision repair and their r elated XP diseases in humans,The predicted protein encodes a leucine z ipper motif. The repE gene is not expressed by mitotically dividing ce lls, and repE mRNA is first detected during the aggregation phase of d evelopment when the cells have ceased dividing and replicating genomic DNA, The mRNA level plateaus by the time the developing cells have en tered multicellular aggregates and remains at the same steady-state le vel for the remainder of development. In addition, we have demonstrate d that the level of mRNA is very low in developing cells. These observ ations suggest that repE may play a regulatory role in development, Th e data indicate that potential developmental roles for XP-related gene s can be profitably studied in this system.