Related Experiment Videos
Structure of the rat PRPS1 gene encoding phosphoribosylpyrophosphate synthetase subunit I
1Department of Biochemistry, Chiba University School of Medicine, Japan.
Insights
Researchers characterized the rat PRPS1 gene, detailing its exon-intron structure and promoter region. Key elements like transcription start sites and binding sites were identified, revealing similarities to housekeeping genes.
Area of Science:
- Molecular Biology
- Gene Regulation
Background:
- Phosphoribosylpyrophosphate (PP-Rib-P) synthetase subunit I (PRPS1) is crucial for nucleotide biosynthesis and is constitutively expressed.
- Understanding the PRPS1 gene's structure and regulation is vital for comprehending cellular metabolism.
Purpose of the Study:
- To elucidate the exon-intron organization of the rat PRPS1 gene.
- To identify the transcription promoter sequence and regulatory elements of the rat PRPS1 gene.
Main Methods:
- Gene sequencing to determine exon-intron boundaries.
- S1 nuclease assays and primer extension to identify transcription start points.
- Bioinformatic analysis to identify promoter elements (TATA, CCAAT, GC boxes).
Main Results:
- The rat PRPS1 gene spans 22 kilobases, comprising 7 exons with varying sizes.
- Four transcription start points were identified, located between 126 and 129 bp upstream of the ATG codon.
- A TATA-like sequence, a CCAAT element, and three GC boxes were found in the promoter region.
- The promoter region showed homology to that of the beta-actin gene, suggesting conserved regulatory mechanisms.
Conclusions:
- The study provides a detailed map of the rat PRPS1 gene structure and its promoter region.
- Identified regulatory elements offer insights into the transcriptional control of PRPS1.
- The findings contribute to understanding the molecular basis of PRPS1 expression in mammals.
Abstract:
Phosphoribosylpyrophosphate (PP-Rib-P) synthetase (EC 2.7.6.1) subunit I gene (PRPS1) is constitutively expressed in various tissues (Taira, M., Iizasa, T., Yamada, K., Shimada, H., and Tatibana, M. (1989) Biochim. Biophys. Acta 1007, 203-208). We report here the exon-intron organization and the transcription promoter sequence of rat PRPS1 gene. This gene has 22 kilobases and is split into 7 exons ranging in size from 99 to 251 base pairs (bp), except for exon 7 (1008 bp). A putative PP-Rib-P binding site is encoded in exon 5. The exon-intron boundaries are similar to the consensus sequences for mammalian introns. S1 nuclease and primer extension assays with the use of RNA from rat Yoshida ascites sarcoma cells led to the identification of four possible transcription start points closely spaced between 126 and 129 bp from the ATG initiation codon. In the upstream region from the transcriptional start sites, we observed a TATA-like sequence (TAATTTAAT) at nucleotides -28, a CCAAT element (AGCCAATC) at nucleotides -80, and three GC boxes (putative Sp1-binding sites) at nucleotides -103, -43, and -10. A comparison of the promoter region for PRPS1 with those of other housekeeping genes revealed a homology resembling that of the beta-actin gene.