Jae Yung Lee

RpS3, a DNA repair endonuclease and ribosomal protein, is involved in apoptosis

It is known that mammalian rpS3 functions as a DNA repair endonuclease and ribosomal protein S3. It was also observed that several ribosomal proteins or DNA repair enzymes are related to apoptosis. We report here a third function of rpS3, induction of apoptosis. The localization of green fluorescent protein (GFP)‐rpS3 is changed to the nuclear membrane when lymphocytic cells undergo rpS3‐induced apoptosis. Transient expression of GFP‐rpS3 activates caspase‐8/caspase‐3 and sensitizes cytokine‐induced apoptosis. Deletion analysis reveals that the two functions of rpS3, DNA repair and apoptosis, use independent functional domains.

Determination of the core promoter regions of the Saccharomyces cerevisiae RPS3 gene.

Ribosomal protein genes (RPG), which are scattered throughout the genomes of all eukaryotes, are subjected to coordinated expression. In yeast, the expression of RPGs is highly regulated, mainly at the transcriptional level. Recent research has found that many ribosomal proteins (RPs) function in multiple processes in addition to protein synthesis. Therefore, detailed knowledge of promoter architecture as well as gene regulation is important in understanding the multiple cellular processes mediated by RPGs. In this study, we investigated the functional architecture of the yeast RPS3 promoter and identified many putative cis-elements. Using beta-galactosidase reporter analysis and EMSA, the core promoter of RPS3 containing UASrpg and T-rich regions was corroborated. Moreover, the promoter occupancy of RPS3 by three transcription factors was confirmed. Taken together, our results further the current understanding of the promoter architecture and trans-elements of the Saccharomyces cerevisiae RPS3 gene.