TY - JOUR
T1 - Characterization of a mutant Leishmania donovani deficient in adenosine kinase activity
AU - Iovannisci, David M.
AU - Ullman, Buddy
N1 - Funding Information:
We would like to thankM s. KathleenB arr, Mr. GeraldW ells, and Dr. Robert Lesterf or measuring inorgapnhico sphatlee velsi n leishmaniaelx tractsW. e would also like to thankM s. Paula Hollingswortfho r technicaal ssistancaen dMs. Lisa Miller and Ms. Ginger Hodgefos r theirh elpi n thep reparatioonf this manuscript. This investigatiorne ceivedfi nanciasl upportfr omthe UNDP/World Bank/WHO SpeciaPl rogrammfeo r Researcahn dT rainingin TropicaDl iseasesa,n dt heN ational Instituteosf Health NationAadl visoryA llergya ndI nfectiouDs iseaseCs ouncil.
PY - 1984/6
Y1 - 1984/6
N2 - From a mutagenized population of wildtype Leishmania donovani promastigotes, a clonal cell line, TUBA2, was isolated by virtue of its ability to survive and grow in 20 μM tubercidin (7-deazaadenosine). The TUBA2 clone was also 1000-fold less sensitive than the parental line to growth inhibition by formycin A, another cytotoxic adenosine analog. Parental and mutant cells, however, were equally sensitive to growth inhibition by formycin B, allopurinol riboside, and 6-thioguanosine. Mutant cell extracts, unlike those prepared from wildtype cells, did not phosphorylate radiolabelled adenosine, tubercidin, or formycin A. Intact adenosine kinase-deficient cells did not accumulate exogenous tubercidin or formycin A but incorporated [14C]adenosine at rates 25% of those found for parental cells. The uptake data suggest that adenosine kinase plays an important role in the metabolism of adenosine but indicate alternative metabolic pathways for this nucleoside. The metabolism of adenosine to the nucleotide level in TUBA2 cells appears to be initiated via deribosylation to adenine. Significant amounts of both adenosine hydrolytic and adenosine phosphorylytic activities have been detected in L. donovani promastigotes. Furthermore, L. donovani extracts could slowly catalyze the deamination of formycin A. The isolation and characterization of adenosine kinase-deficient cells has provided considerable insight into the function of the purine pathway in L. donovani.
AB - From a mutagenized population of wildtype Leishmania donovani promastigotes, a clonal cell line, TUBA2, was isolated by virtue of its ability to survive and grow in 20 μM tubercidin (7-deazaadenosine). The TUBA2 clone was also 1000-fold less sensitive than the parental line to growth inhibition by formycin A, another cytotoxic adenosine analog. Parental and mutant cells, however, were equally sensitive to growth inhibition by formycin B, allopurinol riboside, and 6-thioguanosine. Mutant cell extracts, unlike those prepared from wildtype cells, did not phosphorylate radiolabelled adenosine, tubercidin, or formycin A. Intact adenosine kinase-deficient cells did not accumulate exogenous tubercidin or formycin A but incorporated [14C]adenosine at rates 25% of those found for parental cells. The uptake data suggest that adenosine kinase plays an important role in the metabolism of adenosine but indicate alternative metabolic pathways for this nucleoside. The metabolism of adenosine to the nucleotide level in TUBA2 cells appears to be initiated via deribosylation to adenine. Significant amounts of both adenosine hydrolytic and adenosine phosphorylytic activities have been detected in L. donovani promastigotes. Furthermore, L. donovani extracts could slowly catalyze the deamination of formycin A. The isolation and characterization of adenosine kinase-deficient cells has provided considerable insight into the function of the purine pathway in L. donovani.
KW - Genetics
KW - Leishmania donovani
KW - Purine metabolism
UR - http://www.scopus.com/inward/record.url?scp=0021129825&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=0021129825&partnerID=8YFLogxK
U2 - 10.1016/0166-6851(84)90131-2
DO - 10.1016/0166-6851(84)90131-2
M3 - Article
C2 - 6090896
AN - SCOPUS:0021129825
SN - 0166-6851
VL - 12
SP - 139
EP - 151
JO - Molecular and Biochemical Parasitology
JF - Molecular and Biochemical Parasitology
IS - 2
ER -