High impact information on HPRT1

• The addition of FGF to PAEC increased phosphoribosyl pyrophosphate (PRPP) synthetase activity by approximately 8-fold and the PRPP content by approximately 2-fold, but it did not increase hypoxanthine-guanine phosphoribosyltransferase (HGPRT) activity or hypoxanthine transport [1].
• Levels of G6PD and HPRT RNA were also higher in female morulae and blastocysts than in males, but only G6PD levels were significantly different between the sexes [2].
• G6PD, HPRT and ZFX transcripts were noted in all pre-compaction stage embryos and in female and male blastocysts [2].
• Two genes located on the X chromosome, glucose-6-phosphate dehydrogenase (G6PD) and hypoxanthine phosphoribosyl transferase (HPRT), are involved in controlling the amount of oxygen radicals, and hence they might have influence in embryo development [3].
• Comparison of the hprt mutant frequency by the T cell cloning assay was made in parallel [4].

Biological context of HPRT1

• Whereas the FISH assignment of XIST indicates a similar location on the q-arm of the human and cattle X chromosomes, the locus of HPRT1 supported the assumption of a chromosome rearrangement between the distal half of the q-arm of HSAX and the p-arm of BTAX identified by RH mapping [5].
• Hypoxanthine-guanine phosphoribosyltransferase (HGPRT)-deficient mutants of a bovine kidney cell line (MDBK) were selected following mutagenesis with ethylmethane sulfonate or ICR-170G [6].
• The activity of hypoxanthine phosphoribosyltransferase (HPRT) was determined in the bovine embryo during early embryonic development [7].

Anatomical context of HPRT1

• Characterizing mutagenesis in the hprt gene of rat alveolar epithelial cells [8].
• Specifically, erythrocyte concentration of phosphoribosylpyrophosphate (PRPP) and activities of PRPP synthetase, adenine phosphoribosyltransferase, and hypoxanthine-guanine phosphoribosyltransferase appear to be normal in cattle heterozygous for UMP synthase deficiency [9].

Associations of HPRT1 with chemical compounds

• A significant increase in hprt mutation frequency was detected in alveolar epithelial cells obtained from rats exposed to ENU or alpha-quartz; the latter observation is the first demonstration that crystalline silica exposure is mutagenic in vivo [8].
• Sensitivity of ticks to allopurinol, an inhibitor of hypoxanthine-guanine-phosphoribosyltransferase, supports the importance of purine salvage in this tick and the potential role of nucleotidase in this pathway [10].
• These results indicate that HPRT activity of bovine preimplantation embryos can be microassayed using radiolabeled hypoxanthine, and this assay could provide an alternative method for embryo sexing [7].
• In summary, these studies show that rat alveolar epithelial cells isolated by pronase digestion and Nycodenz separation techniques and cultured in a defined media can be used in a clonal selection assay for mutation in the hprt gene [8].
• The rat alveolar epithelial cell cultures were exposed in vitro to the mutagens ethylnitrosourea (ENU) and H2O2, and mutation in the hprt gene was selected for by culture in the presence of the toxic purine analog, 6-thioguanine (6TG) [8].

Analytical, diagnostic and therapeutic context of HPRT1

• Using a semiquantitative sensitive reverse transcriptase-polymerase chain reaction (RT-PCR) assay, we detected G6PD and HPRT mRNA expression at the early blastocyst stage in all bovine embryos analyzed [3].
• Hypoxanthine-guanine phosphoribosyltransferase (EC 2.4.2.8) from beef brain has been purified 3100-fold to apparent homogeneity using a purification procedure based on GMP-Sepharose affinity chromatography [11].

References