Abstract
A kinetic study of the early changes in uridine- and phosphate-transport rates and 3′:5′-cyclic AMP levels induced by the addition of serum to quiescent 3T3 cells revealed that the increase in phosphate uptake and the decrease in the intracellular concentration of 3′:5′-cyclic AMP immediately follow the addition of serum. In contrast, the increase in uridine transport occurred after a lag of several minutes and was clearly preceded by the other changes. The activation of phosphate transport involved an increase in Vmax, while a more complex pattern was observed for uridine transport. A possible role of phosphate in connection with the other early events was also studied. The addition of phosphate to quiescent cells produced a time-dependent decrease in 3′:5′-cyclic AMP levels and this ion was required for full activation of uridine transport by serum. The results show that the increase in phosphate transport is a primary event in the reinitiation of growth and suggest that the increase in phosphate transport may be connected with subsequent metabolic steps.
Keywords: fibroblasts, membrane, tissue culture, growth regulation
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- Aaronson S. A., Todaro G. J. Development of 3T3-like lines from Balb-c mouse embryo cultures: transformation susceptibility to SV40. J Cell Physiol. 1968 Oct;72(2):141–148. doi: 10.1002/jcp.1040720208. [DOI] [PubMed] [Google Scholar]
- Burger M. M., Bombik B. M., Breckenridge B. M., Sheppard J. R. Growth control and cyclic alterations of cyclic AMP in the cell cycle. Nat New Biol. 1972 Oct 11;239(93):161–163. doi: 10.1038/newbio239161a0. [DOI] [PubMed] [Google Scholar]
- Cunningham D. D., Pardee A. B. Transport changes rapidly initiated by serum addition to "contact inhibited" 3T3 cells. Proc Natl Acad Sci U S A. 1969 Nov;64(3):1049–1056. doi: 10.1073/pnas.64.3.1049. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Gilman A. G. A protein binding assay for adenosine 3':5'-cyclic monophosphate. Proc Natl Acad Sci U S A. 1970 Sep;67(1):305–312. doi: 10.1073/pnas.67.1.305. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Holley R. W. A unifying hypothesis concerning the nature of malignant growth. Proc Natl Acad Sci U S A. 1972 Oct;69(10):2840–2841. doi: 10.1073/pnas.69.10.2840. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Johnson G. S., Morgan W. D., Pastan I. Regulation of cell motility by cyclic AMP. Nature. 1972 Jan 7;235(5332):54–56. doi: 10.1038/235054a0. [DOI] [PubMed] [Google Scholar]
- Kram R., Mamont P., Tomkins G. M. Pleiotypic control by adenosine 3':5'-cyclic monophosphate: a model for growth control in animal cells. Proc Natl Acad Sci U S A. 1973 May;70(5):1432–1436. doi: 10.1073/pnas.70.5.1432. [DOI] [PMC free article] [PubMed] [Google Scholar]
- LOWRY O. H., ROSEBROUGH N. J., FARR A. L., RANDALL R. J. Protein measurement with the Folin phenol reagent. J Biol Chem. 1951 Nov;193(1):265–275. [PubMed] [Google Scholar]
- Maganiello V., Vaughan M. Prostaglandin E 1 effects on adenosine 3':5'-cyclic monophosphate concentration and phosphodiesterase activity in fibroblasts (mouse L cells-tissue culture-enzyme kinetics-prostaglandin homologues). Proc Natl Acad Sci U S A. 1972 Jan;69(1):269–273. doi: 10.1073/pnas.69.1.269. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Otten J., Johnson G. S., Pastan I. Regulation of cell growth by cyclic adenosine 3',5'-monophosphate. Effect of cell density and agents which alter cell growth on cyclic adenosine 3',5'-monophosphate levels in fibroblasts. J Biol Chem. 1972 Nov 10;247(21):7082–7087. [PubMed] [Google Scholar]
- Sheppard J. R. Difference in the cyclic adenosine 3',5'-monophosphate levels in normal and transformed cells. Nat New Biol. 1972 Mar 1;236(61):14–16. doi: 10.1038/newbio236014a0. [DOI] [PubMed] [Google Scholar]
- Weber M. J., Edlin G. Phosphate transport, nucleotide pools, and ribonucleic acid synthesis in growing and in density-inhibited 3T3 cells. J Biol Chem. 1971 Mar 25;246(6):1828–1833. [PubMed] [Google Scholar]
- Weber M. J., Rubin H. Uridine transport and RNA synthesis in growing and in density-inhibited animal cells. J Cell Physiol. 1971 Apr;77(2):157–168. doi: 10.1002/jcp.1040770205. [DOI] [PubMed] [Google Scholar]