Adding phosphorylation events to the core oscillator driving the cell cycle of fission yeast

Abstract

Much is known about the regulatory elements controlling the cell cycle in fission yeast (Schizosaccharomyces pombe). This regulation is mainly done by the (cyclin-dependent kinase/cyclin) complex (Cdc2/Cdc13) that activates specific target genes and proteins via phosphorylation events during the cell cycle in a time-dependent manner. However, more work is still needed to complement the existing gaps in the current fission yeast gene regulatory network to be able to overcome abnormalities in its growth, repair and development, i.e. explain many phenomena including mitotic catastrophe. In this work we complement the previously presented core oscillator of the cell cycle of fission yeast by selected phosphorylation events and study their effects on the temporal evolution of the core oscillator based Boolean network. Thereby, we attempt to establish a regulatory link between the autonomous cell cycle oscillator and the remainder of the cell. We suggest the unclear yet regulatory effect of phosphorylation on the added components, and discuss many unreported points regarding the temporal evolution of the cell cycle and its components. To better visualize the results regardless of the programming background we developed an Android application that can be used to run the core and extended model of the fission yeast cell cycle step by step.

Modification of Transfer RNA Levels Affects Cyclin Aggregation and the Correct Duplication of Yeast Cells

“…The effects observed in our work may be the result of several different events, such as aggregation of other proteins that drag Cdc13, impairment of chaperones to properly fold Cdc13, or effects on other cyclins. However, the observed effects are consistent with the role of Cdc13 in forming the complex described above ( Hayles et al, 1994 ; Humaidan et al, 2018 ) and the cell replication problem as a consequence of replacing rare Gly codons in cdc13. Further experiments are required to confirm whether there is a direct effect on Cdc13 folding and aggregation that alters the cell cycle.…”

“…Cdc13 is one of the most widely studied cyclins from the fission yeast, S. pombe . It forms a complex and activates Cdc2 (Cdk1), an important kinase in G2/M transition ( Humaidan et al, 2018 ). Cdc13 is preferentially expressed during this transition.…”