Abstract
Rapid kinetic techniques were employed to measure the transport of adenine in adenine phosphoribosyltransferase-deficient L929 and Chinese hamster ovary (CHO) cells in zero-trans entry and exit and equilibrium exchange procedures. The kinetic parameters of transport were computed by fitting appropriate integrated rate equations to time courses of transmembrane equilibration of radiolabeled adenine. Adenine transport conformed to the simple carrier model with directional symmetry and equal mobility of loaded and empty carrier. The Michaelis-Menten constants and maximum velocities for various strains of L929 cells fell between 2.3 and 3.5 mM and 90 and 150 pmol/microliters of cell water per s, respectively, values similar to those previously reported for CHO and Novikoff hepatoma cells. The corresponding values for hypoxanthine transport in L929 cells were 413 microM and 16 pmol/microliters of cell water per s. Adenine transport velocities were directly proportional to adenine concentrations between 0.03 and 50 microM in both CHO and Novikoff cells. The results indicate that adenine is transported in these cells by a single, low-affinity, high-capacity transporter. Adenine transport was inhibited by hypoxanthine in some cell strains, but not in others. Adenine also rapidly bound to L929 cells in a saturable manner (KD = 18 microM), presumably to the cell surface (about 3 X 10(7) sites per cell).
Full text
PDF








Selected References
These references are in PubMed. This may not be the complete list of references from this article.
- Cohen A., Ullman B., Martin D. W., Jr Characterization of a mutant mouse lymphoma cell with deficient transport of purine and pyrimidine nucleosides. J Biol Chem. 1979 Jan 10;254(1):112–116. [PubMed] [Google Scholar]
- Cybulski R. L., Fry D. W., Goldman I. D. Adenosine stimulation of uphill adenine transport in L1210 leukemia cells. Evidence for a novel countertransport mechanism. J Biol Chem. 1981 May 10;256(9):4455–4459. [PubMed] [Google Scholar]
- Lucas A., Flintoff W., Anderson R., Percy D., Coulter M., Dales S. In vivo and in vitro models of demyelinating diseases: tropism of the JHM strain of murine hepatitis virus for cells of glial origin. Cell. 1977 Oct;12(2):553–560. doi: 10.1016/0092-8674(77)90131-3. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Marz R., Wohlhueter R. M., Plagemann P. G. Purine and pyrimidine transport and phosphoribosylation and their interaction in overall uptake by cultured mammalian cells. A re-evaluation. J Biol Chem. 1979 Apr 10;254(7):2329–2338. [PubMed] [Google Scholar]
- Müller M. M., Kraupp M., Falkner G., de Bruyn C. H. Uptake of purine bases by HGPRT deficient erythrocytes. Monogr Hum Genet. 1978;10:116–121. doi: 10.1159/000401579. [DOI] [PubMed] [Google Scholar]
- Plagemann P. G., Marz R., Erbe J. Transport and countertransport of thymidine in ATP depleted and thymidine kinase-deficient Novikoff rat hepatoma and mouse L cells: evidence of a high Km facilitated diffusion system with wide nucleoside specificity. J Cell Physiol. 1976 Sep;89(1):1–18. doi: 10.1002/jcp.1040890102. [DOI] [PubMed] [Google Scholar]
- Plagemann P. G. Nucleotide pools of Novikoff rat hepatoma cells growing in suspension culture. I. Kinetics of incorporation of nucleosides into nucleotide pools and pool sizes during growth cycle. J Cell Physiol. 1971 Apr;77(2):213–240. doi: 10.1002/jcp.1040770212. [DOI] [PubMed] [Google Scholar]
- Plagemann P. G., Swim H. E. Replication of mengovirus. I. Effect on synthesis of macromolecules by host cell. J Bacteriol. 1966 Jun;91(6):2317–2326. doi: 10.1128/jb.91.6.2317-2326.1966. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Plagemann P. G., Wohlhueter R. M. The hypoxanthine transporter of Novikoff rat hepatoma cells exhibits directional symmetry and equal mobility when empty or substrate-loaded. Biochim Biophys Acta. 1982 Jun 14;688(2):505–514. doi: 10.1016/0005-2736(82)90362-5. [DOI] [PubMed] [Google Scholar]
- Schneider E. L., Stanbridge E. J., Epstein C. J. Incorporation of 3H-uridine and 3H-uracil into RNA: a simple technique for the detection of mycoplasma contamination of cultured cells. Exp Cell Res. 1974 Mar 15;84(1):311–318. doi: 10.1016/0014-4827(74)90411-x. [DOI] [PubMed] [Google Scholar]
- Suresh M. R., Henderson G. B., Huennekens F. M. Folate uptake in L1210 cells: mediation by an adenine transport system. Biochem Biophys Res Commun. 1979 Mar 15;87(1):135–139. doi: 10.1016/0006-291x(79)91657-7. [DOI] [PubMed] [Google Scholar]
- Taylor M. W., Pipkorn J. H., Tokito M. K., Pozzatti R. O., Jr Purine mutants of mammalian cell lines: III. Control of purine biosynthesis in adenine phosphoribosyl transferase mutants of CHO cells. Somatic Cell Genet. 1977 Mar;3(2):195–206. doi: 10.1007/BF01551814. [DOI] [PubMed] [Google Scholar]
- Templeton B. A., Chilson O. P. Adenine transport by mature rabbit erythrocytes. J Biol Chem. 1981 Jan 10;256(1):285–290. [PubMed] [Google Scholar]
- Weder H. G., Schildknecht J., Lutz R. A., Kesselring P. Determination of binding parameters from Scatchard plots. Theoretical and practical considerations. Eur J Biochem. 1974 Mar 1;42(2):475–481. doi: 10.1111/j.1432-1033.1974.tb03361.x. [DOI] [PubMed] [Google Scholar]
- Wohlhueter R. M., Marz R., Graff J. C., Plagemann P. G. A rapid-mixing technique to measure transport in suspended animal cells: applications to nucleoside transport in Novikoff rat hepatoma cells. Methods Cell Biol. 1978;20:211–236. doi: 10.1016/s0091-679x(08)62020-8. [DOI] [PubMed] [Google Scholar]
- Wohlhueter R. M., Marz R., Plagemann P. G. Properties of the thymidine transport system of Chinese hamster ovary cells as probed by nitrobenzylthioinosine. J Membr Biol. 1978 Sep 19;42(3):247–264. doi: 10.1007/BF01870361. [DOI] [PubMed] [Google Scholar]
