Resistance of Erythrocyte Adenine Phosphoribosyltransferase in the Lesch-Nyhan Syndrome to Destabilization to Heat by Hypoxanthine

1974 ◽  
pp. 215-220 ◽  
Author(s):  
P. Bashkin ◽  
O. Sperling ◽  
R. Schmidt ◽  
A. Szeinberg
Keyword(s):  
Adenine Phosphoribosyltransferase

The Uptake of Adenine by Isolated Human Platelet Membranes

1974 ◽  
Vol 32 (02/03) ◽  
pp. 457-464
Author(s):  
Paul C. French ◽  
Jan J. Sixma ◽  
Holm Holmsen
Keyword(s):  
Human Platelet ◽  
Facilitated Diffusion ◽  
Adenine Phosphoribosyltransferase ◽  
Ph Optimum ◽  
Intact Cells ◽  
Platelet Membranes ◽  
Group Translocation ◽  
Triton X

SummaryAdenine uptake into isolated platelet membranes had about the same Km (151 ± 21 • 9 nM) as uptake into intact cells (159 ± 21 nM) and was also competitively inhibited by papaverine and hypoxanthine. No uptake occurred at 0° and accumulated adenine was converted to AMP. AMP was not firmly bound to protein as judged by chromatography of triton X-100 solubilized membranes on Sephadex G25. The pH optimum for adenine uptake was at pH 5-5. Exogenous 5-phosphoribosyl-l-pyrophos- phate strongly stimulated uptake. These data may be explained by uptake of adenine by facilitated diffusion followed by conversion to AMP by adenine phosphoribosyltransferase but group translocation cannot be entirely excluded.

Crystallization of the purine salvage enzyme adenine phosphoribosyltransferase

1996 ◽  
Vol 25 (4) ◽  
pp. 510-513 ◽  
Author(s):  
Cynthia L. Phillips ◽  
Buddy Ullman ◽  
Richard G. Brennan
Keyword(s):  
Adenine Phosphoribosyltransferase ◽  
Purine Salvage

scholarly journals Adenine Phosphoribosyltransferase from Monkey Liver

1969 ◽  
Vol 244 (17) ◽  
pp. 4779-4784
Author(s):  
T A Krenitsky ◽  
S M Neil ◽  
G B Elion ◽  
G H Hitchings
Keyword(s):  
Adenine Phosphoribosyltransferase ◽  
Monkey Liver

scholarly journals Allele frequency of variants reported to cause adenine phosphoribosyltransferase deficiency

2021 ◽  
Author(s):  
Hrafnhildur L. Runolfsdottir ◽  
John A. Sayer ◽  
Olafur S. Indridason ◽  
Vidar O. Edvardsson ◽  
Brynjar O. Jensson ◽  
...  
Keyword(s):  
Allele Frequency ◽  
Autosomal Recessive Disorder ◽  
European Population ◽  
Adenine Phosphoribosyltransferase ◽  
Genomic Databases ◽  
Pathogenic Variants ◽  
Adenine Phosphoribosyltransferase Deficiency ◽  
Variation Database ◽  
The Uk ◽  
Aprt Deficiency

AbstractAdenine phosphoribosyltransferase deficiency is a rare, autosomal recessive disorder of purine metabolism that causes nephrolithiasis and progressive chronic kidney disease. The small number of reported cases indicates an extremely low prevalence, although it has been suggested that missed diagnoses may play a role. We assessed the prevalence of APRT deficiency based on the frequency of causally-related APRT sequence variants in a diverse set of large genomic databases. A thorough search was carried out for all APRT variants that have been confirmed as pathogenic under recessive mode of inheritance, and the frequency of the identified variants examined in six population genomic databases: the deCODE genetics database, the UK Biobank, the 100,000 Genomes Project, the Genome Aggregation Database, the Human Genetic Variation Database and the Korean Variant Archive. The estimated frequency of homozygous genotypes was calculated using the Hardy-Weinberg equation. Sixty-two pathogenic APRT variants were identified, including six novel variants. Most common were the missense variants c.407T>C (p.(Met136Thr)) in Japan and c.194A>T (p.(Asp65Val)) in Iceland, as well as the splice-site variant c.400 + 2dup (p.(Ala108Glufs*3)) in the European population. Twenty-nine variants were detected in at least one of the six genomic databases. The highest cumulative minor allele frequency (cMAF) of pathogenic variants outside of Japan and Iceland was observed in the Irish population (0.2%), though no APRT deficiency cases have been reported in Ireland. The large number of cases in Japan and Iceland is consistent with a founder effect in these populations. There is no evidence for widespread underdiagnosis based on the current analysis.

scholarly journals Cellular and Molecular Mechanisms of Kidney Injury in 2,8-Dihydroxyadenine Nephropathy

2020 ◽  
Vol 31 (4) ◽  
pp. 799-816 ◽  
Author(s):  
Barbara Mara Klinkhammer ◽  
Sonja Djudjaj ◽  
Uta Kunter ◽  
Runolfur Palsson ◽  
Vidar Orn Edvardsson ◽  
...  
Keyword(s):  
Clinical Relevance ◽  
Molecular Mechanisms ◽  
Granulomatous Inflammation ◽  
Kidney Injury ◽  
Rare Condition ◽  
Therapeutic Interventions ◽  
Renal Tubules ◽  
Rodent Models ◽  
Adenine Phosphoribosyltransferase ◽  
Reparative Process

BackgroundHereditary deficiency of adenine phosphoribosyltransferase causes 2,8-dihydroxyadenine (2,8-DHA) nephropathy, a rare condition characterized by formation of 2,8-DHA crystals within renal tubules. Clinical relevance of rodent models of 2,8-DHA crystal nephropathy induced by excessive adenine intake is unknown.MethodsUsing animal models and patient kidney biopsies, we assessed the pathogenic sequelae of 2,8-DHA crystal-induced kidney damage. We also used knockout mice to investigate the role of TNF receptors 1 and 2 (TNFR1 and TNFR2), CD44, or alpha2-HS glycoprotein (AHSG), all of which are involved in the pathogenesis of other types of crystal-induced nephropathies.ResultsAdenine-enriched diet in mice induced 2,8-DHA nephropathy, leading to progressive kidney disease, characterized by crystal deposits, tubular injury, inflammation, and fibrosis. Kidney injury depended on crystal size. The smallest crystals were endocytosed by tubular epithelial cells. Crystals of variable size were excreted in urine. Large crystals obstructed whole tubules. Medium-sized crystals induced a particular reparative process that we term extratubulation. In this process, tubular cells, in coordination with macrophages, overgrew and translocated crystals into the interstitium, restoring the tubular luminal patency; this was followed by degradation of interstitial crystals by granulomatous inflammation. Patients with adenine phosphoribosyltransferase deficiency showed similar histopathological findings regarding crystal morphology, crystal clearance, and renal injury. In mice, deletion of Tnfr1 significantly reduced tubular CD44 and annexin two expression, as well as inflammation, thereby ameliorating the disease course. In contrast, genetic deletion of Tnfr2, Cd44, or Ahsg had no effect on the manifestations of 2,8-DHA nephropathy.ConclusionsRodent models of the cellular and molecular mechanisms of 2,8-DHA nephropathy and crystal clearance have clinical relevance and offer insight into potential future targets for therapeutic interventions.

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