THE PEA3 PROTEIN OF THE ETS ONCOGENE FAMILY IS A PUTATIVE TRANSCRIPTIONAL MODULATOR OF THE MOUSE EPIDIDYMIS-SPECIFIC GLUTATHIONE-PEROXIDASEGENE GPX5

This report presents data that suggest that the tissue-restricted poly oma enhancer activator protein (PEA3) of the Ets oncogene family of DN A-binding proteins is a putative modulator of the epididymis-specific glutathione peroxidase 5 gene gpx5. Northern and polymerase chain reac tions on reverse-transcribed epididymal RNAs were used to show that th e PEA3 factor is spatially and temporally expressed within the mouse e pididymis in a manner consistent with gpx5 characteristics of expressi on. Then, using cotransfection experiments carried out in heterologous tissue-culture cells with various deletions of the gpx5 promoter driv ing a CAT reporter gene, we have shown that the transcriptional activi ty of the gpx5 promoter is modulated by the presence of the PEA3 prote in. Subsequently, we have shown using gel-shift assays that DNA sequen ces located within the 5' flanking region of the gpx5 gene have the ab ility to bind specifically to the PEA3 protein. Finally, using Norther n assays we present data that suggest that PEA3 mRNA accumulation in t he mouse caput epididymidis is controlled by androgens and testicular factors. Altogether, these results strongly suggest that the PEA3 fact or might participate in the transcriptional control of the murine epid idymis caput-specific gpx5 gene. (C) 1998 Wiley-Liss, Inc.