Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P00492 (hypoxanthine-guanine phosphoribosyltransferase)
 2,385 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Three patients with the Lesch-Nyhan syndrome were found to have normal delayed hypersensitivity, peripheral-blood T-lymphocyte counts, lymphocyte responses to P.H.A., and serum IgM, IgA, and IgE levels. However, the percentages of B-lymphocytes, IgG levels, serum-isohaemagglutinin titres, and lymphocyte responses to pokeweed mitogen (P.W.M.) were subnormal. These observations suggest that activity of the salvage pathway of purine synthesis catalysed by hypoxanthine-guanine phosphoribosyl transferase (H.G.P.R.T.) is not required for the responses of T-lymphocytes to mitogenic or antigenic stimulation, but may contribute to the proliferation and function of B lymphocytes. The major role of the de-novo pathway of purine synthesis in human lymphocyte responses to mitogenic or antigenic stimulation is shown by the effects of inhibitors of this pathway, including immunosuppressive agents, and by the effects of congenital deficiency or inhibition of adenosine deaminase.
Lancet 1975 Dec 13
PMID:Immunological observations on patients with Lesch-Nyhan syndrome, and on the role of de-novo purine synthesis in lymphocyte transformation. 5 61

The spot corresponding to hypoxanthine phosphoribosyltransferase (HPRT; IMP:pyrophosphate phosphoribosyltransferase, EC 2.4.2.8) has been identified in two-dimensional polyacrylamide gels of HeLa cell extracts. This spot is absent in gels of 24 HPRT dificient mutants. A missense mutant displays a new HPRT spot at the same molecular weight but different isoelectric focusing position. Five independently isolated revertants of the missense mutant display spots corresponding to both the wild-type and mutant proteins indicating that they synthesize HPRT from two separate genes. If the missense protein is synthesized from a mutated form of the initially active HPRT gene, then wild-type HPRT protein in the revertants must be snythesized from a newly activated but prevously silent wild-type gene. The newly activated gene in the revertants of the missense mutation appears unstable producing a high frequency of spontaneous HPRT mutants.
Proc Natl Acad Sci U S A 1976 Dec
PMID:Analysis of HeLa cell hypoxanthine phosphoribosyltransferase mutants and revertants by two-dimensional polyacrylamide gel electrophoresis: evidence for silent gene activation. 6 48

Somatic cell hybrids were constructed between BALB/c-RAG mouse cells and feline lymphoma cells by the hypoxanthine-aminopterin-thymidine selection scheme. RAG cells spontaneously produce an endogenous B-tropic type C virus. Cat-mouse hybrids preferentially segregate feline chromosomes and retain murine chromosomes-demonstrable by karyotypic and isozyme analyses. Despite the presence of the complete mouse genome, including the viral genome, virus production was diminished to 1-5% of the levels observed in RAG parents based upon particle-associated RNA-dependent DNA polymerase (reverse transcriptase) activity in the culture fluid. Thirty-seven hybrids made on four different occasions had suppressed virus levels, and no hybrids expressed parental virus levels. Reverse selection experiments on 6-thioguanine demonstrated that a restriction gene, tentatively named Bvr-1, was linked to the feline structural genes for hypoxanthine phosphoribosyltransferase (IMP:pyrophosphate phosphoribosyltransferase; EC 2.4.4.8) and glucose-6-phosphate dehydrogenase (D-glucose-6-phosphate: NADP+ 1-oxidoreductase; EC 1.1.1.49) in cats, probably on the X-chromosome. The genetic mode of action of Bvr-1 is trans dominant in restriction of murine leukemia virus. The restriction locus results in a block late in virus maturation but prior to release, since expression of antigens for viral structural proteins and matrue budding particles is apparent on surfaces of restriced hybrid cells but not in high-speed pellets from culture fluid of restricted cells.
Proc Natl Acad Sci U S A 1976 Dec
PMID:Bvr-1, a restriction locus of a type C RNA virus in the feline cellular genome: identification, location, and phenotypic characterization in cat X mouse somatic cell hybrids. 6 49

The mutagenicity and cytotoxicity of 19 ICR compounds, including 6 reported previously, have been determined in the Chinese hamster ovary/hypoxanthine-guanine phosphoribosyltransferase system. As with other physical and chemical agents, ICR 170 and 191 exhibit a phenotypic expression time of 7 to 9 days, independent of concentrations tested. Thirteen of these compounds are mutagenic. At equimolar concentrations, the compounds with the tertiary amine-type side chain (ICR 217, 340, 355, 368, 170, and 292) are more mutagenic than the compounds with the secondary amine-type side chain (ICR 449, 371, 191, and 372). All secondary amine types show a "plateau" in their concentration-dependent mutagenesis curves at 3 to 4 microM. Shortening of the side chain by one carbon (ICR 171) results in a reduced mutagenicity. Substitution of a sulfur atom for a nitrogen in the side chain (ICR 342) increases both mutagenicity and cytotoxicity. The presence of two 2-chloroethyl groups on the side chain (ICR 220) also results in greatly increased cytotoxicity and mutagenicity. When the 2-chloroethyl group of ICR 340, 372, 292, 191, or 170 is replaced by a 2-hydroxyethyl group (ICR 340-OH, 372-OH, 292-OH, 191-OH, or 170-OH), a mutagenically inactive compound results which remains toxic. Replacement of the amine linkage with an ether linkage (ICR 283) also yields a mutagenically inactive compound.
Cancer Res 1979 Dec
PMID:Mutagenicity and cytotoxicity of nineteen heterocyclic mustards (ICR compounds) in cultured mammalian cells. 9 29

Mutagenized stem cells of a cultured mouse teratocarcinoma cell line were selected for resistance to the purine base analog 6-thioguanine. Cells of a resistant clone were completely deficient in activity of the enzyme hypoxanthine phosphoribosyltransferase (HPRT, IMP:pyrophosphate phosphoribosyltransferase, EC 2.4.2.8), the same X-linked lesion as occurs in human Lesch-Nyhan disease. After microinjection into blastocysts of another genetic strain, the previously malignant cells successfully participated in normal embryogenesis and tumor-free, viable mosaic mice were obtained. Cells of tumor lineage were identified by strain markers in virtually all tissues of some individuals. Mature function of those cells was evident from their tissue-specific products (e.g., melanins, liver proteins). These mutagenized teratocarcinoma cells are therefore developmentally totipotent. Retention of the severe HPRT deficiency in the differentiated state was documented in extracts of mosaic tissues by depressed specific activity of the enzyme, and also by presence of unlabeled clones in autoradiographs of explanted cells incubated in [(3)H]hypoxanthine. Some mosaic individuals had mutant-strain cells in only one or a few tissues. Such animals may provide unique opportunities to identify the tissue sources of particular aspects of the complex disease syndrome. The tissue distribution of HPRT-deficient cells suggests that selection against them is particularly strong in blood of the mosaic mice, as is already known to be the case in human heterozygotes. This phenotypic parallelism supports the expectation that afflicted F(1) male mice that might be obtained from mutant germ cells can serve as a model of the human disease.
Proc Natl Acad Sci U S A 1977 Dec
PMID:Mosaic mice with teratocarcinoma-derived mutant cells deficient in hypoxanthine phosphoribosyltransferase. 27 82

Two brothers were found to have athetoid cerebral palsy, mental and growth retardation and evidence of self mutilation. One had passed a renal calculus and both had high serum uric acid levels. The diagnosis of Lesch-Nyhan syndrome was confirmed by the finding of low levels of hypoxanthine-guanine phosphoribosyl transferase in erythrocytes and by autoradiography of fibriblasts. The mother, maternal grandmother, a female sibling and a maternal aunt were identified as carriers of the X-linked mutation which was responsible for the enzyme deficiency in the two male siblings.
N Z Med J 1977 Dec 14
PMID:The Lesch-Nyhan syndrome: a family study. 27 69

Unknown concentrations of orotic acid can be measured by competition with a known amount of [carboxyl-14C]orotic acid for reaction with a limiting amount of phosphoribosylpyrophosphate in the presence of orotate phosphoribosyltransferase and orotidine monophosphate decarboxylase. The dilution of the specific radioactivity in the product 14CO2 is a sensitive and accurate measure of the amount of orotic acid present in the sample. Orotidine can also be determined after hydrolytic cleavage to orotic acid. The method was used to measure orotic acid and orotidine in urine samples from newborns, healthy controls and patients with gout or deficiency of hypoxanthine-guanine phosphoribosyltransferase receiving allopurinol. Urinary excretion of orotic acid and orotidine in newborns was similar whether the infants were breast-fed or received milk powder. The excretion of orotidine was increased in all patients receiving allopurinol. After allopurinol administration orotic acid excretion was increased in gouty patients but close to normal values in patients with deficiency of hypoxanthine-guanine phosphoribosyltransferase. The results are discussed in relation to the mechanism by which allopurinol inhibits pyrimidine metabolism.
Clin Chim Acta 1978 Dec 15
PMID:The urinary excretion of orotic acid and orotidine, measured by an isotope dilution assay. 36 97

The results are described of a behavioural programme designed to modify self-injurious behaviour of a child with Lesch-Nyhan syndrome. The treatment combined extinction of the injurious behaviour and reinforcement of alternative behaviour, and was successful in the controlled hospital environment. However, an attempt to teach the parents to continue the treatment at home failed. The results are discussed in terms of the possible relationship between organic and environmental factors in maintaining the injurious behaviour, and the importance of analysing both the behaviour itself and the factors (including familial) maintaining it. It is suggested that parents should be advised about management of behavioural problems at an early age.
Dev Med Child Neurol 1979 Dec
PMID:Problems in the behavioural treatment of self-injury in the Lesch-Nyhan syndrome. 52 Jul 17

The patient, H.Chr.B., was among the first reported with hyperuricemia and central nervous system symptoms. He has been found to have a variant of hypoxanthine guanine phosphoribosyl transferase (HPRT; E.C.2.4.2.8) distinct from the enzyme present in patients with the Lesch-Nyhan syndrome. The patient had chroeoathetosis, spasticity, dysarthric speech, and hyperuricemia. However, his intelligence was normal and he had no evidence of self-mutilation. There was no activity of HPRT in the lysates of erythrocytes and cultured fibroblasts when analyzed in the usual manner. Using a newly developed method for the study of purine metabolism in intact cultured cells, this patient was found to metabolize some 9% of 8-14C-hypoxanthine, and 90% of the isotope utilized was converted to adenine and guanine nucleotides. In contrast, cells from patients with the Lesch-Nyhan syndrome were virtually completely unable to convert hypoxanthine to nucleotides. The patient's fibroblasts were even more efficient in the metabolism of 8-14C-guanine, which was utilized to the extent of 27%, over 80% of which was converted to guanine and adenine nucleotides. The growth of the cultured fibroblasts of this patient was intermediate in media containing hypoxanthine aminopterin thymidine (HAT), whereas the growth of Lesch-Nyhan cells was inhibited and normal cells grew normally. Similarly in 8-azaguanine, 6-thioguanine, and 8-azahypoxanthine, the growth of the patient's cells was intermediate between normal and Lesch-Nyhan cells. These observations provide further evidence for genetic heterogeneity among patients with disorders in purine metabolism involving the HPRT gene. They document that this famous patient did not have the Lesch-Nyhan syndrome.
Pediatr Res 1979 Dec
PMID:Utilization of purines by an HPRT variant in an intelligent, nonmutilative patient with features of the Lesch-Nyhan syndrome. 52 96

Genes coding for enzymes functioning in purine salvage pathways have been located on the chromosome of Escherichia coli. The gene add encoding adenosine deaminase was located by transduction at 31 min, the gene order was established to be man-uidA-add-aroD. A deletion covering man-uidA-add was obtained. The gene gsk encoding guanosine kinase was cotransducible with purE and shown to be located at 13 min. The gene hpt encoding hypoxanthine phosphoribosyltransferase was cotransducible with tonA indicating a location at 3 min. The location of the gene gpt encoding guanine (xanthine) phosphoribosyltransferase in the proA-proB region was confirmed.
Mol Gen Genet 1975 Dec 30
PMID:Location on the chromosome of Escherichia coli of genes governing purine metabolism. Adenosine deaminase (add), guanosine kinase (gsk) and hypoxanthine phosphoribosyltransferase (hpt). 76 47


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