Phosphoribosylpyrophosphate synthetase and the regulation of phosphoribosylpyrophosphate production in human cells.
between purine nucleoside diphosphate inhibition and inorganic phosphate (Pi) activation; and intracellular concentration of the PRS1 isoform. The operation of additional determinants of rates of PRPP synthesis in human cells is suggested by: (1) multiple PRS isoforms with distinctive physical and kinetic properties; (2) nearly immediate activation of intracellular PRPP synthesis in response to mitogens, growth-promoters, and increased intracellular Mg2+ concentrations; (3) tissue-specific differences in PRS1 and PRS2 transcript and isoform expression; and (4) reversible association of PRS subunits with one another and/or with PRS-associated proteins (PAPs), as a result of which the catalytic and perhaps regulatory properties of PRS isoforms are modified.
Becker
M A
MA
The Unversity of Chicago, University of Chicago Medical Center, Illinois 60637, USA.
D000595:Amino Acid Sequence; D001412:Bacillus subtilis / Q000201:enzymology / Q000235:genetics; D006801:Humans; D007527:Isoenzymes / Q000037:antagonists & inhibitors / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D008954:Models, Biological; D008969:Molecular Sequence Data; D010754:Phosphoribosyl Pyrophosphate / Q000096:biosynthesis*; D012268:Ribose-Phosphate Pyrophosphokinase / Q000037:antagonists & inhibitors / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D017386:Sequence Homology, Amino Acid
D007527:Isoenzymes; D010754:Phosphoribosyl Pyrophosphate; D012268:Ribose-Phosphate Pyrophosphokinase