Human urate oxidase gene: Cloning and partial sequence analysis reveal a stop codon within the fifth exon

Rat urate oxidase produced by recombinant baculovirus expression: formation of peroxisome crystalloid core-like structures.

“…The absence of urate oxidase in humans and hominoid primates has been shown recently to be due to nonsense mutations in the urate oxidase gene (4)(5)(6). The presence of normal urate oxidase cDNA sequences in the Old and New World monkeys [such as baboon, rhesus monkey, and squirrel monkey (4,6)] and the indication that the structure of the urate oxidase gene is highly conserved during evolution (4-7) suggest that a mutational event leading to the silencing of this gene in humans and hominoid primates is a relatively recent evolutionary event (2,6).…”

“…Recently, the molecular cloning of urate oxidase cDNA from some species (4,9) and the determination of the structure of rat urate oxidase gene (7) have generated considerable interest in the evolutionary aspects of this gene (4)(5)(6). Furthermore, since this gene is expressed exclusively in the liver ofmost mammals, it provides a valuable system for studying tissue-specific regulation of gene expression (9).…”

Molecular Analysis, Subcellular Localization and Tissue Distribution of Enzymes Involved in Uric Acid Degradation.

“…The relatively higher levels of uric acid in human and hominoid primates is postulated to contribute to increased life span and decreased incidences of cancer compared to other vertebrates, in view of the potent antioxidant properties exhibited by uric acid [3]. In the rat, and in most other animals that possess urate oxidase activity, this enzyme is associated with the crystalloid or semidense inclusions present within the peroxisomes in hepatic parenchymal cells, whereas human liver peroxisomes lack such cores, which is consistent with the absence of this enzyme in humans [1,6,14,22,24,25 [27,31,32,34,35]. Although, the presence of urate oxidase in peroxisomes has been well established, there is some confusion as to the subcellular localization of allantoinase and allantoicase [27,33].…”

“…Most mammals, with the exception of human and hominoid primates, have urate oxidase activity in their livers and excrete allantoin as the end product of purine metabolism, as these animals have lost allantoinase and allantoicase [7,13]. The absence of urate oxidase activity in humans and primates accounts for the excretion of uric acid in these species [7,31,33,34], whereas the presence of all three enzymes responsible for the uric acid metabolism in lower vertebrates, for example fish and frog, results in the breakdown of uric acid all the way to urea and glyoxylic acid [8,18,23]. The relatively higher levels of uric acid in human and hominoid primates is postulated to contribute to increased life span and decreased incidences of cancer compared to other vertebrates, in view of the potent antioxidant properties exhibited by uric acid [3].…”

Optimum conditions for uricase enzyme production by Gliomastix gueg

“…The first important application discovered for uricase was in clinical biochemistry as a diagnostic reagent for measurement of uric acid in blood and other biological fluids (Adamek et al, 1989). Higher primates (apes and humans) lack functional uricase and excrete uric acid as the end product of purine degradation (Friedman et al, 1985;Yeldandi et al, 1990). In some individuals, uric acid precipitates, leading to gout symptoms.…”