Genetic ablation of purine salvage in Cryptosporidium parvum reveals nucleotide uptake from the host cell

• DOI: 10.1073/pnas.1908239116
• Publication Date: 2019-10-01T01:54:38Z
• Authors: Mattie C. Pawlowic; Mastanbabu Somepalli; Adam Sateriale; Gillian T. Herbert; Alexis R. Gibson; Gregory D. Cuny; Lizbeth Hedstrom; Boris Striepen
• Keywords: Nucleotide salvage; Cryptosporidium parvum; Inosine monophosphate

The apicomplexan parasite Cryptosporidium is a leading global cause of severe diarrheal disease and an important contributor to early-childhood mortality. Waterborne outbreaks occur frequently, even in countries with advanced water treatment capabilities, there currently no fully effective treatment. Nucleotide pathways are attractive targets for antimicrobial development, several laboratories designing inhibitors these enzymes as potential infections. Here we take advantage newly available molecular genetics parvum investigate nucleotide biosynthesis by directed gene ablation. Surprisingly, found that the tolerates loss classical including dihydrofolate reductase-thymidylate synthase (DHFR-TS) inosine monophosphate dehydrogenase (IMPDH). We show thymidine kinase provides route absence DHFR-TS. In contrast, only single pathway has been identified C. purine salvage. Nonetheless, multiple pathway, well adenosine transporter, can be ablated. resulting mutants viable under normal conditions but hypersensitive inhibition synthesis their host cell. might use as-yet undiscovered transporters salvage enzymes; however, genetic pharmacological experiments led us conclude imports nucleotides from ATP uptake significant impact on our understanding energy metabolism given lacks oxidative phosphorylation glycolytic not constitutively expressed throughout life cycle.