The periodic synthesis of thymidine kinase has been studied in the naturally synchronous acellular slime mold, Physarum polycephalum. Density-shift experiments indicate that the peak of enzyme activity which appears 30-45 min past metaphase represents actual synthesis of the enzyme protein. Synthesis can be prevented by prior exposure of the plasmodium to actinomycin D, cycloheximide, or γ-radiation. For each of these three agents, time periods exist in the mitotic cycle during which mitosis and the synthesis of thymidine kinase become insensitive to that agent. These time periods are not coincident: for enzyme synthesis the transition period for actinomycin D occurs up to 15 min earlier in the mitotic cycle than the period for 9500 R of γ-radiation which, in turn, occurs 5-15 min earlier than that for cycloheximide. It is therefore proposed that γ-radiation interferes with a metabolic event which takes place after actinomycin D-sensitive transcription but prior to the completion of cycloheximide-sensitive translation.
Skip Nav Destination
Article navigation
1 September 1972
Research Article|
September 01 1972
The Radiation-Sensitivity of Mitosis and the Synthesis of Thymidine Kinase in Physarum polycephalum: A Comparison to the Sensitivity to Actinomycin D and Cycloheximide
Radiat Res (1972) 51 (3): 638–653.
Citation
Nancy L. Oleinick; The Radiation-Sensitivity of Mitosis and the Synthesis of Thymidine Kinase in Physarum polycephalum: A Comparison to the Sensitivity to Actinomycin D and Cycloheximide. Radiat Res 1 September 1972; 51 (3): 638–653. doi: https://doi.org/10.2307/3573632
Download citation file:
Sign in
Don't already have an account? Register
Client Account
You could not be signed in. Please check your email address / username and password and try again.
Sign in via your Institution
Sign in via your InstitutionCiting articles via
Commonalities Between COVID-19 and Radiation Injury
Carmen I. Rios, David R. Cassatt, Brynn A. Hollingsworth, Merriline M. Satyamitra, Yeabsera S. Tadesse, Lanyn P. Taliaferro, Thomas A. Winters, Andrea L. DiCarlo
Radiofrequency Fields and Calcium Movements Into and Out of Cells
Andrew Wood, Ken Karipidis
Studies of the Mortality of Atomic Bomb Survivors, Report 14, 1950–2003: An Overview of Cancer and Noncancer Diseases
Kotaro Ozasa, Yukiko Shimizu, Akihiko Suyama, Fumiyoshi Kasagi, Midori Soda, Eric J. Grant, Ritsu Sakata, Hiromi Sugiyama, Kazunori Kodama
Germicidal Efficacy and Mammalian Skin Safety of 222-nm UV Light
Manuela Buonanno, Brian Ponnaiya, David Welch, Milda Stanislauskas, Gerhard Randers-Pehrson, Lubomir Smilenov, Franklin D. Lowy, David M. Owens, David J. Brenner
Hypoxanthine Reduces Radiation Damage in Vascular Endothelial Cells and Mouse Skin by Enhancing ATP Production via the Salvage Pathway
Megumi Fujiwara, Nana Sato, Ken Okamoto