Abstract
The single-stranded DNA and RNA binding protein, Purα, has recently received special attention as this protein, by associating with the specific nucleotide sequence (GGN repeats) and/or several important cellular and viral proteins regulates crucial biological events such as transcription, replication, and cell proliferation. In this study, we focused on the promoter activity of the Purα upstream DNA sequence and demonstrated that the sequence spanning 6,000 nucleotides upstream of the Purα transcription start site has promoter activity in various cell types. Results from promoter deletion studies revealed that this region encompasses various regulatory motifs which differentially participate in the promoter activity of Purα in various cells. The transcription start site of Purα is surrounded by the GA/GC-rich sequence which exhibits the ability to interact with Purα, suggesting a role for autoregulation of Purα transcription. Results from co-transfection studies revealed that ectopic expression of Purα reduced transcriptional activity of the Purα promoter and the region located between amino acid residues, 1–85 of Purα is important for the observed autoregulatory event. The regulatory protein of the human neurotropic virus, JCV, T-antigen, which interacts with Purα, decreased transcriptional activity of the Purα promoter. Co-expression of JCV T-antigen and Purα had no significant effect on the suppression of Purα gene transcription by either protein. The importance of this finding in light of earlier results showing down regulation of Purα during JCV infection of glial cells is discussed. © 2001 Wiley-Liss, Inc.
Published Version
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