PYRIMIDINE SALVAGE IN GIARDIA-LAMBLIA
PYRIMIDINE SALVAGE IN GIARDIA-LAMBLIA
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DOI：
10.1084/jem.161.3.437
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发表时间：
1985-01-01
影响因子：
15.3
通讯作者：
WANG, CC
中科院分区：
文献类型：
--
作者：
ALDRITT, SM;TIEN, P;WANG, CC
The anaerobic protozoan parasite G. lamblia is incapable of de novo pyrimidine metabolism, as shown by its inability to incorporate orotate, bicarbonate and aspartate into the pyrimidine nucleotide pool. Results from high performance liquid chromatography of pyrimidine and pyrimidine nucleoside pulse-labeled nucleotide pools and enzyme assays suggest that the parasite satisfies its pyrimidine nucleotide needs predominantly through salvage of uracil by a cytoplasmic uracil phosphoribosyltransferase. Exogenous uridine and cytidine are primarily converted to uracil by the action of uridine hydrolase and cytidine deaminase before incorporation into nucleotide pools. Direct salvage of cytosine occurs, to a relatively limited extent, via cytosine phosphoribosyltransferase. G. lamblia relies on salvage of exogenous thymidine for TMP synthesis, accomplished primarily through the action of a 100,000 g-pelletable thymidine phosphotransferase.
