Year: 2003
Type: article
Abstract: Recently, it has been shown that cyclin B1 was degraded mainly before the onset of anaphase in mammalian cells. When a nondegradable form of cyclin B1 was introduced into cells, the metaphase-anaphase transition was blocked. This blockage was not due to a failure in activating anaphase-promoting complex, nor was it due to a failure of degradation of securin. To resolve the question of whether this blockage by overexpressing the nondegradable form of cyclin B1 is physiologically relevant or not, we developed a novel method to estimate the relative protein level of the overexpressed cyclin B1 mutant within an individual cell. We found that a low level of nondegradable cyclin B1 (less than 30% of the endogenous cyclin B1) was sufficient to block the metaphase-anaphase transition, implying that the blockage of anaphase onset by the nondegradable cyclin B1 was not due to an artifact of excessive M-phase-promoting factor activity. This result suggests that, in mammalian cells, the majority of cyclin B1 must be destroyed before the cell can enter anaphase.
Source: Journal of Biological Chemistry
Authors: Donald C. Chang, Naihan Xu, Kathy Q. Luo
Language: English
Subfield: Cell Biology
Domain: Life Sciences
Open Access status: hybrid
Estimated APC paid: $3,430
OpenAlex ID: W2005411204