TY - JOUR
T1 - Experimental modulation of PRPP availability for ribonucleotide synthesis from hypoxanthine in human skin febroblast cultures
AU - Holland, Mary Jean C
AU - Klein, Natalie C.
AU - Cox, Rody P.
N1 - Funding Information:
This researchw as supportedi n part by the Samuel A. Berger Foundationa nd by USPHS grant AM 14528. Dr Holland is an Arthritis Foundation Fellow. The experimentalw ork was completedw hile Dr Klein was a Genetics Trainee (Training Grant GM 00047).
PY - 1978/2
Y1 - 1978/2
N2 - The intracellular concentration of the cosubstrate 5-phosphoribosyl 1-pyrophosphate (PRPP) may be rate-limiting for the reactions, catalysed by hypoxanthine phosphoribosyltransferase, by which mammalian cells convert the purine bases hypoxanthine, xanthine, and guanine to their ribonucleotide derivatives. The rate of conversion of [14C]hypoxanthine to radioactive phosphorylated products by intact human diploid skin fibroblasts was measured in the presence of compounds previously reported to alter PRPP concentration in a variety of cell types Methylene blue, previously reported to increase PRPP concentration in a variety of cultured cells including skin fibroblasts, increased product formation from hypoxanthine, with maximum effect following 60 min preincubation with 0.4 mM. Incubation with adenine, orotic acid, allopurinol, or adenosine has been shown to decrease PRPP concentration. Of these compounds, only adenine and adenosine decreased the rate of ribonucleotide synthesis from hypoxanthine in cultured skin fibroblasts. This decrease probably resulted from decreased PRPP synthesis rather than increased PRPP utilization. The reaction products isolated from cells following incubation with either [14C]adenine or [14C]adenosine included adenosine monophosphate and adenosine diphosphate, both inhibitors of PRPP synthetase.
AB - The intracellular concentration of the cosubstrate 5-phosphoribosyl 1-pyrophosphate (PRPP) may be rate-limiting for the reactions, catalysed by hypoxanthine phosphoribosyltransferase, by which mammalian cells convert the purine bases hypoxanthine, xanthine, and guanine to their ribonucleotide derivatives. The rate of conversion of [14C]hypoxanthine to radioactive phosphorylated products by intact human diploid skin fibroblasts was measured in the presence of compounds previously reported to alter PRPP concentration in a variety of cell types Methylene blue, previously reported to increase PRPP concentration in a variety of cultured cells including skin fibroblasts, increased product formation from hypoxanthine, with maximum effect following 60 min preincubation with 0.4 mM. Incubation with adenine, orotic acid, allopurinol, or adenosine has been shown to decrease PRPP concentration. Of these compounds, only adenine and adenosine decreased the rate of ribonucleotide synthesis from hypoxanthine in cultured skin fibroblasts. This decrease probably resulted from decreased PRPP synthesis rather than increased PRPP utilization. The reaction products isolated from cells following incubation with either [14C]adenine or [14C]adenosine included adenosine monophosphate and adenosine diphosphate, both inhibitors of PRPP synthetase.
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U2 - 10.1016/0014-4827(78)90166-0
DO - 10.1016/0014-4827(78)90166-0
M3 - Article
C2 - 627232
AN - SCOPUS:0017876076
SN - 0014-4827
VL - 111
SP - 237
EP - 243
JO - Experimental Cell Research
JF - Experimental Cell Research
IS - 2
ER -