Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound   Target Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound

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Query: EC:2.4.2.8 (hypoxanthine-guanine phosphoribosyltransferase)
2,527 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Twenty independent man-mouse (Cl1D,LA/TK-, HPRT-) and man-hamster (CH,HPRT-) hybrids using female human cells with balanced reciprocal translocation XX,t(X;5)(q21;q11) were analyzed for human genes localized on chromosome 5 (HEXB), on chromosome X (PGK, GALA, HPRT, G6PD) and for the different chromosomes in relation with the balanced reciprocal translocation (chr.5, chr.5q-, chr.Xq+, chr.X). The different results obtained indicate that the genes for human markers HEXB, PGK are on Xq+, and that the genes for human markers GALA, G6PD are on 5q-. These data implicate finally the following localizations: HEXB on 5q11 leads to 5qter; PGK on Xq21 leads to Xpter; GALA, HPRT, G6PD on Xq21 leads to Xqter.
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PMID:Regional localization of the genes for human HEXB. PGK, GALA. HPRT, G6PD by somatic cell hybridization. 627 30

Hypoxanthine phosphoribosyltransferase-deficient (HPRT-) F9-derived teratocarcinoma stem cells carrying an SV40 genome (12-16TG cells) were fused with Mus caroli (M. car.) spleen cells, and a stem cell hybrid containing reduced numbers of M. car. chromosomes was isolated (BC6 stem cell). The BC6 cells containing an active X chromosome from each parental cell were induced to differentiate in retinoic acid, and differentiated clones were isolated. Most differentiated clones retained both parental X chromosomes in active form. One differentiated clone, BC6-13, grew equally well in hypoxanthine/aminopterin/thymidine (HAT) selective medium (which requires an active M. car. HPRT (E.C.2.4.2.8) locus) or in 6-thioguanine (6TG, which would require either loss or inactivation of the M. car. HPRT locus). Using cDNA probes for HPRT and phosphoglycerate kinase (PGK) (E.C.2.7.2.3) loci and biochemical assays for HPRT and PGK enzymes, it was shown that BC6-13 cells, whether grown in nonselective medium, HAT medium, or 6TG-containing medium, retain the HPRT and PGK genes of both parental cells, but the M. car. forms of HPRT and PGK were inactivated in cells treated with 6TG. 6-Thioguanine seems to act as an inducer, one effect of which is X chromosome inactivation, which seems to be complete and irreversible as early as 24 h after addition of 6TG to BC6-13 cells.
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PMID:Activity of X-linked genes in stem and differentiated Mus musculus X Mus caroli hybrid cells. 654 51

Somatic cell hybrid clones were derived from the fusion of hypoxanthine phosphoribosyltransferase (HPRT; EC 2.4.2.8)-deficient mouse cells and two different human fibroblast strains, each carrying an X chromosome-autosome translocation. One of these had an X/11 translocation [46,X,t(X;11)(p21;q13)] and the other had an X/19 translocation [46,X,t(X;19)(q22;q13)]. The structurally normal human X chromosome is the late-replicating (genetically inactive) chromosome in these two cell strains; the rearranged X chromosome is early replicating (genetically active). One primary hybrid clone carrying both the translocated X chromosome and the structurally normal X chromosome was isolated in hypoxanthine/aminopterin/thymidine medium from each of these two cell fusion experiments. These clones were then selected in medium containing 8-azaguanine to achieve the loss of the active human HPRT locus. Five subclones from the cell hybrid with the X/11 translocation failed to express two known human X-chromosome markers [glucose-6-phosphate dehydrogenase (G6PD; EC 1.1.1.49) and phosphoglycerate kinase (PGK; EC 2.7.2.3)] but did express human microsomal steroid sulfatase (STS; sterol-sulfate sulfohydrolase, EC 3.1.6.2). Three of these were cytogenetically analyzed and found to contain a structurally normal human X chromosome but not the X/11 translocation. Two subclones were isolated in 8-azaguanine from the hybrid with the X/19 translocation. Cytogenetic analysis of these two clones showed the presence of a structurally normal human X chromosome; the X/19 translocation was not present. They did not express human G6PD, PGK, or HPRT but did express human STS. These results indicate that human STS is expressed from a locus on the inactive human X chromosome and support our earlier finding that the STS locus escapes X-inactivation in man.
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PMID:Expression of an X-linked gene from an inactive human X chromosome in mouse-human hybrid cells: further evidence for the noninactivation of the steroid sulfatase locus in man. 693 82

We have established a cell line from mouse kidney cells expressing the tfm mutation and showed that these cells lack androgen binding activity. A subclone of these simian virus 40 (SV40)-transformed cells (6TGR-SV-tfm) selected in 6-thioguanine and lacking hypoxanthine phosphoribosyltransferase was used to produce a series of mouse--human hybrids containing the normal human X chromosome or various X autosome-translocation chromosomes (expressing only segments of the human X chromosome). When the androgen receptor locus (AR) was present in the hybrid, the number of receptor sites and kinetics of binding were similar to that in the human parental cells. Analysis of hybrids with partial human X chromosomes by using assays for X chromosome-linked enzymes and for the androgen receptor protein indicate that the AR locus on the human X chromosome is near the centromere between Xq13 and Xp11 and is proximal to the locus for phosphoglycerate kinase. Hybrids derived from 6TGR-SV-tfm mouse cells and human labial fibroblasts from an XY individual with the ar- form of androgen insensitivity have no binding activity. The lack of complementation indicates that the X chromosome-linked mutations in mouse and man affect homologous loci and supports the evolutionary conservation of X chromosomal loci in mammals; however, the position of the locus on the human X chromosome indicates that intrachromosomal rearrangement has occurred.
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PMID:Studies of the locus for androgen receptor: localization on the human X chromosome and evidence for homology with the Tfm locus in the mouse. 694 33

The karyotype of microcebus murinus (MIM) (lemuridae) is considered by Dutrillaux (1979) as the closest to the karyotype ancestral to all primates. A large number of homoeologies exists between the banding patterns of MIM chromosomes and those of man (HSA). We report a comparison of the gene maps of these two species which confirms most of these homoeologies. Fifteen cell hybrids were obtained by fusing MIM fibroblasts and an HPRT- Chinese hamster cell line. Twenty-seven enzyme markers were investigated. The following assignments were demonstrated: NP to chromosome MIM 2, homoeologous to HSA 14; the syntenic group PGD-ENO1-PGM1 to MIM 3, homoeologous to HSA 1p; LDHA to MIM 5, homoeologous to HSA 11; Me1 to MIM 6, homoeologous to HSA 6; the syntenic group LDHB-CS-PEPB-ENO2-TPI to MIM 7, homoeologous to HSA 12; the syntenic group AK1-AK3 to MIM 10, which we considered to be homoeologous to HSA 9 (we do not consider MIM 9 to be homoeologous to HSA 9, as does Dutrillaux, 1979); GOT1 to MIM 15, homoeologous to HSA 10; the syntenic group HPRT-G6PD-PGK-GLA to MIM X. Synteny dissociation in three hybrids suggests closer linkage between G6PD and HPRT than between PGK-GLA and HPRT. Three syntenic groups, known in man, were confirmed in MIM but could not be assigned with full confidence: ACP1-MDH1, MP1-PKM2, and PEPD-GPI. GUK1 and PEPC, known to be syntenic in man, were found to be asyntenic in MIM and could not be assigned. PGM2 and SOD1 could not be assigned. A comparison of these gene assignments with those known in Cebus capucinus showed a remarkable homoeology for six chromosomes of the two species.
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PMID:Gene mapping of Microcebus murinus (Lemuridae): a comparison with man and Cebus capucinus (Cebidae). 695 81

Thirteen pig-hamster and fifteen pig-mouse hybrid ceil lines were developed. These lines eliminate the pig chromosomes preferentially. The following syntenies were demonstrated: G6PD, PGK, HPRT, and PKM2, MPI.
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PMID:[Gene mapping in the pig (Sus scrofa 1.). I. Study of two syntenic groups G6PD, PGK, HPRT and PKM2, MPI (author's transl)]. 696 34

RJK39 is a clone of Chinese hamster cells carrying a mutation which inactivates hypoxanthine-guanine phosphoribosyltransferase (HGPRT) and reduces the apparent molecular weight of the enzyme. Using mutagens, we have isolated subclones of RJK39 which will grow in the counterselective HAT medium. Some continue to be HGPRT-deficient and survived the selection because they are resistant to aminopterin. In all but one of the HGPRT-positive revertants, the molecular weight of the enzyme returned to the wild-type value. However, the phenotypes of several of those strains indicate they produce altered forms of HGPRT, and one can conclude that second-site mutations must be able to cause intragenic suppression of the original mutation in RJK39. One of the revertants is pseudotetraploid and functionally heterozygous at the HGPRT locus. Segregation studies with that clone localized the genes for HGPRT, glucose-6-phosphate dehydrogenase, and phosphoglycerate kinase to the short arm of the Chinese hamster X chromosome.
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PMID:Reversion of a mutation affecting the molecular weight of HGPRT: intragenic suppression and localization of X-linked genes. 719 35

Inherited variations in monoamine oxidase (MAO) activity are thought to affect human behavior and expression of disease. The present study has established the chromosomal location of one of the structural genes coding for this enzyme. Mapping was carried out by somatic cell hybridization between normal human skin fibroblasts and mouse neuroblastoma cells. Selective media for growth of cells with or without hypoxanthine phosphoribosyltransferase (HPRT) activity were used to obtain hybrid lines which had retained or lost the human X chromosome, respectively. Cytogenetic techniques, isozyme analysis, and limited proteolysis and peptide mapping of [3H]pargyline-labeled MAO were used to characterize hybrid lines. With one exception, only lines containing the human X chromosome and human forms of two X-linked enzymes (phosphoglycerate kinase and glucose-6-phosphate dehydrogenase) expressed the human form of the flavin polypeptide of type A MAO. The exceptional hybrid line contained a putative translocation of part of the human X chromosome, since it expressed human forms of both MAO and phosphoglycerate kinase but neither the human form of glucose-6-phosphate dehydrogenase nor HPRT activity. This evidence indicates that the structural gene for the flavin polypeptide of MAO-A is on the human X chromosome. This represents the first chromosomal assignment of a human gene coding for an enzyme of neurotransmitter metabolism. This information will help to elucidate the structure of MAO and modes of its inheritance in the human population.
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PMID:Gene for monoamine oxidase type A assigned to the human X chromosome. 719 39

Twenty three allogeneic bone marrow transplant (BMT) patients with female donors and 23 female autologous transplant patients were assessed for clonality status after transplant to determine the nature of haemopoietic reconstitution. The X chromosome probes PGK, HPRT and M27 beta were used to assess clonality by analysis of X chromosome inactivation. Results were obtained for 15 allogeneic patients, 14 of whom gave polyclonal results after transplantation. One patient gave a skewed pattern of X chromosome inactivation after transplant due to extreme Lyonisation of the donor cells. Results were obtained from 19 autologous transplant patients, 17 of whom gave polyclonal results after transplant. Two patients gave patterns of skewed X chromosome inactivation in post-transplant samples, reflected in their constitutive DNA, due to extreme Lyonisation. The remaining patients could not be assessed because of hypermethylation of HpaII sites or indistinguishable digested and undigested alleles using M27 beta probe analysis. Haemopoietic reconstitution after allogeneic and autologous BMT, in our patients, was found to be polyclonal. Skewed patterns of X chromosome inactivation seen after transplant were due to extreme Lyonisation of the infused haemopoietic cells.
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PMID:Clonality studies in patients undergoing allogeneic and autologous bone marrow transplantation for haematological malignancies. 774 60

The restriction fragment length polymorphisms (RFLP) of the X-chromosome phosphoglycerate kinase (PGK) and hypoxanthine phosphoribosyltransferase (HPRT) genes were used to study the clonal basis of the chronic myeloproliferative disorders (CMPD). Analyses were performed on granulocyte and T-lymphocyte fractions obtained from 24 females; 13 had essential thrombocythaemia (ET), eight polycythaemia vera (PV) and three myelofibrosis with myeloid metaplasia (MMM). All 24 of these patients had monoclonal patterns of X-inactivation in the granulocyte fraction. For the T-lymphocyte fraction, non-clonal patterns of X-inactivation were observed in 8/13 patients with ET, 7/8 with PV and 1/3 with MMM, while the remaining eight subjects were found to have monoclonal patterns of X-inactivation. Our findings suggest that the majority of the CMPD in these patients originated from a relatively committed progenitor cell without the capacity to differentiate into T cells, and convincingly demonstrated heterogeneity of lineage involvement.
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PMID:Clonality in chronic myeloproliferative disorders defined by X-chromosome linked probes: demonstration of heterogeneity in lineage involvement. 798 39


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