Effects of ionizing radiation on cyclin expression in HeLa cells.
The levels of cyclin B mRNA and protein rise rapidly in G2 + M phase, and fall at the end of mitosis. The studies described here were initiated to determine the effects of ionizing radiation on the level of cyclin B bearing in mind that the division delay induced by ionizing radiation might be influenced by the expression of cyclin B. After irradiation in S phase, the cyclin B mRNA in HeLa cells was measured as the cells proceeded through the cell cycle. Instead of the usual rise, after irradiation cyclin B mRNA levels remained low during the G2 delay. After irradiation in G2 phase, cyclin B mRNA was readily detectable although at slightly lower levels than in the controls. However, cyclin B protein was markedly decreased in amount.
Muschel
R J
RJ
Department of Pathology and Laboratory Medicine, University of Pennsylvania, Philadelphia.
Zhang
H B
HB
Iliakis
G
G
McKenna
W G
WG
D002453:Cell Cycle / Q000235:genetics / Q000528:radiation effects*; D016213:Cyclins / Q000096:biosynthesis* / Q000235:genetics; D006367:HeLa Cells / Q000528:radiation effects; D006801:Humans; D007700:Kinetics; D012333:RNA, Messenger / Q000378:metabolism*; D016196:S Phase / Q000528:radiation effects*; D014965:X-Rays
D016213:Cyclins; D012333:RNA, Messenger