title: Chinese hamster ovary cell mutants specifically affected in the phosphorylation of C-purine nucleosides.
abstract: In Chinese hamster ovary cells, two different types of mutants resistant to purine nucleoside analogs have been isolated. One type of mutants selected in presence of C-nucleosides formycin A and formycin B (FomR mutants) exhibited a high degree of cross resistance to different C-nucleosides but showed very slight to no cross resistance to various N-nucleosides. In contrast, mutants selected in presence of toyocamycin (Toyr mutants) exhibited a high degree of cross resistance to all C- and N-adenosine analogs. Studies on the cellular uptake and phosphorylation of [3H]adenosine, [3H]tubercidin, and [3H]formycin A show that, unlike the Toyr mutants which show reduced phosphorylation of all three compounds, the FomR mutants show reduced cellular phosphorylation of only [3H]formycin A. It is suggested that the genetic lesion in the FomR mutants affects adenosine kinase in a novel manner that specifically affects the phosphorylation of C-purine nucleosides.
mesh_terms: D000241:Adenosine / Q000378:metabolism; D000818:Animals; D000903:Antibiotics, Antineoplastic / Q000494:pharmacology*; D002460:Cell Line; D006224:Cricetinae; D003412:Cricetulus; D004351:Drug Resistance; D005260:Female; D005573:Formycins / Q000494:pharmacology*; D010053:Ovary / Q000378:metabolism*; D010766:Phosphorylation; D011684:Purine Nucleosides / Q000378:metabolism* / Q000494:pharmacology; D012254:Ribavirin / Q000031:analogs & derivatives / Q000494:pharmacology; D013997:Time Factors; D014372:Tubercidin / Q000494:pharmacology
chemical_list: D000903:Antibiotics, Antineoplastic; D005573:Formycins; D011684:Purine Nucleosides; D012254:Ribavirin; D000241:Adenosine; D014372:Tubercidin; C033706:tiazofurin