Changes in CDK activity - the cause or result of the cell cycle alterations upon temperatures shifts?

0469987 - MBÚ 2017 JP eng A - Abstrakt
Bišová, Kateřina - Ivanov, Ivan - Zachleder, Vilém
Changes in CDK activity - the cause or result of the cell cycle alterations upon temperatures shifts?
Book of Abstract of the 17th International Conference on the Cell and Molecular Biology of Chlamydomonas. Kyoto, 2016.
[17th International Conference on Cell and Molecular Biology of Chlamydomonas. 26.06.2016-01.07.2016, Kyoto]
Grant CEP: GA ČR GA15-09231S
Institucionální podpora: RVO:61388971
Kód oboru RIV: EA - Morfologické obory a cytologie

Changes of growth conditions, such as light and temperature, have profound effect on growth and cell cycle progression. We have been interested in the immediate effect of light and temperature changes on cell growth and cell cycle progression in transfer experiments. Transfers between two temperatures (20°C, 30°C) differing by 10°C will speed up cell cycle progression in the up-shifted cells and slow it down in down-shifted cells even if the cells are put into dark. Similarly, cells moved from sub-lethal temperature (39°C) blocking nuclear and cell division will divide if down-shifted into dark at 30°C. We have been interested in mechanism underlining these processes and studied potential involvement of the key cell cycle regulators, cyclin-dependent kinases. The kinase activity changed dramatically upon the temperature transfer and correlated to the individual cell cycle processes as in the standard conditions. Thus, the peaks of kinase activities appeared 10 or more hours earlier in the cultures transferred to dark at 30°C than in the cultures transferred to dark at 20°C. At 30°C the kinase activity stayed high immediately upon transfer and increased soon after similarly to the light grown culture. In contrast, at 20°C the kinase activity decreased upon the transfer and was maintained at low level until it was again activated concomitantly with the running cell cycle process (nuclear or cellular division). The kinase activities in cultures shifted from 39°C to 30°C mimicked the kinetics of kinase activities in the control grown at 30°C on light. The results suggest presence of an inhibitor regulating CDK activity that is either stabilized at 20°C or fast degraded at 30°C. We assume that such protein might be a part of the coordination between growth and cell cycle entry at commitment point.

Trvalý link: http://hdl.handle.net/11104/0268271