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

Thioguanine-resistant primary clones were grown from single cell suspensions obtained from dog and human kidneys by enzymatic digestion. In medium containing a relatively high concentration (10 micrograms/ml) of thioguanine, thioguanine-resistant primary clones arose from each source at frequencies ranging from 10(-4) to 10(-5). A reduction in total hypoxanthine uptake was found in the thioguanine-resistant primary clones which had developed in thioguanine medium, consistent with a reduction in hypoxanthine phosphoribosyltransferase activity. When these thioguanine-resistant primary clones were subsequently grown in the absence of thioguanine and assayed for the thioguanine-resistant phenotype and hypoxanthine phosphoribosyltransferase activity, it was found that most were now thioguanine-sensitive and yielded cell-free extracts with substantial amounts of hypoxanthine phosphoribosyltransferase activity. In contrast, thioguanine-resistant human clones grown continuously in the presence of thioguanine yielded cell-free extracts with little or no detectable hypoxanthine phosphoribosyltransferase activity. Southern blot analysis demonstrated no structural alterations in the hypoxanthine phosphoribosyltransferase gene in thioguanine-resistant primary human kidney clones. These results suggest that a novel mechanism(s) for thioguanine resistance and the control of hypoxanthine phosphoribosyltransferase expression may occur in dog and human kidney cells.
 ...
PMID:A novel class of unstable 6-thioguanine-resistant cells from dog and human kidneys. 323 32

Thioguanine-resistant T lymphoblast populations were selectively amplified using T cell growth factor in the cultures of peripheral blood T cells from four Lesch-Nyhan heterozygotes. Although Lesch-Nyhan T lymphoblasts were all thioguanine-resistant, none of the cultures from 13 control subjects yielded the growth of such defective cell populations. These data provide direct evidence for the existence of a small percentage (5%-40%) of hypoxanthine-guanine phosphoribosyltransferase (HGPRT) deficient T cells in the heterozygotes, but not in normal individuals. Conversely, culture of the T lymphoblasts with azaserine plus hypoxanthine permitted the growth of the other part of the cell population that was enzyme positive. The low percentages of HGPRT-negative cells among T cells in heterozygotes suggest that the presence of this enzyme is beneficial for differentiation of lymphocytes of T cell linkage. Considering the ease and the reliability, culture of the peripheral T cells with thioguanine and T cell growth factor is very likely of practical use for detecting Lesch-Nyhan syndrome carriers among predisposed females.
 ...
PMID:A new method for the detection of Lesch-Nyhan heterozygotes by peripheral blood T cell culture using T cell growth factor. 660 83

Electroporation is a recent technique used to introduce exogenous DNA into eukaryotic cells. It is important to establish that the gene of interest is transferred into a functional, non-mutated recipient cell. V79/AP4 Chinese hamster cells were exposed to high-voltage pulsed electric fields and some biological and genetic effects were measured. The results showed that cytotoxicity was related in a dose-dependent manner to the number of applied pulses. Thioguanine-resistant colony-forming cells as well as chromosomal aberrations were also induced whereas ouabain resistants and sister-chromatid exchanges were not or slightly induced. Spontaneous and electroporation-induced clones that were phenotypically TGR/HATS were used to investigate the hprt locus. Molecular screening of the locus showed that the number of deleted exons was significantly higher in induced than in spontaneous TG-resistant clones, suggesting that the genetic damages induced by electroporation concern the loss of regions well over the size of the hprt locus.
 ...
PMID:Analysis of electroporation-induced genetic damages in V79/AP4 Chinese hamster cells. 768 57