Effect of cAMP on nucleoside metabolism II. Cell cycle dependence of thymidine transport

✍ Scribed by Barbra A. Roller; Kanji Hirai; Vittorio Defendi

• Book ID: 102882446
• Publisher: John Wiley and Sons
• Year: 1974
• Tongue: English
• Weight: 849 KB
• Volume: 84
• Category: Article
• ISSN: 0021-9541
• DOI: 10.1002/jcp.1040840302

✦ Synopsis

Abstract

We have shown previously that adenosine 3′5′ cyclic monophosphate (cAMP) increased the transport of thymidine into monkey cells (CV‐1) without affecting DNA synthesis (Roller et al., '74). Using techniques of cell synchronization, cell separation and DNA synthesis inhibitors in CV‐1 and other cell lines, we now report that thymidine transport at low thymidine concentrations increases during the S phase of the cell cycle and that initiation of DNA synthesis is necessary for thymidine transport, although continuation of DNA synthesis is not necessary. Cyclic AMP alters nucleoside transport by increasing the Vmax for the transport reaction, but has no effect on the Km. Cyclic AMP is found not to affect the time in the cell cycle when thymidine transport occurs or the quality of the transport reaction, and only affects the amount of thymidine transported.