Cell Cycle Dynamics in Yeast Systems

The eukaryotic cell cycle in yeast unfolds as an ordered sequence of events—G1 (growth), S (DNA synthesis), G2 (preparation) and M (mitosis)—coordinated by cyclin-dependent kinases (CDKs) and their cyclin partners. Entry into the cycle, known as START, is governed by G1 cyclins (Cln proteins) whose activity phosphorylates the transcriptional repressor Whi5, triggering activation of SBF/MBF transcription factors and commitment to DNA replication. Feedback loops—both positive and negative—ensure irreversibility and robustness, while multisite phosphorylation imparts ultrasensitivity, coupling cell size to division. Stress-responsive inhibitors such as Cip1 transiently delay START under adverse conditions, integrating environmental cues with growth signals. Recent advances have mapped dynamic phosphoproteomes through synchronised cultures, revealing extensive cross-talk between metabolism and cycle progression. Mathematical and stochastic models now capture noise buffering and size homeostasis, making yeast a versatile platform for understanding fundamental regulators of proliferation across eukaryotes and for informing drug discovery and synthetic biology applications.

Research from Nature Portfolio

Functional analysis of a stress-induced CDK inhibitor demonstrated that yeast Cip1, co-regulated by Mcm1 and Msn2/4, binds Cdk1–G1 cyclin complexes at multiple phosphorylation sites to impose a transient G1 arrest under osmotic stress. This work highlights a conserved strategy akin to metazoan p21 in safeguarding genomic integrity. A quantitative model of G1/S control centred on multisite phosphorylation of Whi5 showed that progressive modification of decoy and functional sites by Cln3–Cdk1 and Cln1/2–Cdk1 generates a coherent, size-dependent switch for transcriptional activation. Finally, a synthetic regulable Cdk1 module revealed that periodic transcriptional programmes are not autonomous oscillators but directly tuned by precise Cdk1 activity thresholds, establishing CDK as a quantitative platform coordinating cell cycle transitions with the expression of phase-specific gene clusters.

Cell Cycle Dynamics in Yeast Systems publication trend

The graph below shows the total number of articles in cell cycle dynamics in yeast systems across all publications each year (not limited to Nature Index journals).

Technical terms

Cyclin-dependent kinase (CDK): Enzyme whose activity fluctuates through association with cyclins to drive cell cycle transitions.

Cyclin: Regulatory subunit that activates CDKs in specific cell cycle phases.

START: G1 checkpoint in yeast marking the irreversible commitment to DNA replication and division.

Phosphorylation: Reversible addition of phosphate groups to proteins, modulating activity, stability and interactions.

Multisite phosphorylation: Modification of multiple sites on a protein, creating switch-like responses to kinase activity.

SBF/MBF: Transcription factor complexes (Swi4-Swi6/Mbp1-Swi6) that regulate G1/S gene expression.

References

1. Reliable cell cycle commitment in budding yeast is ensured by signal integration. eLife (2015).
2. Design Principles of the Yeast G1/S Switch. PLOS Biology (2013).
3. Homeostatic control of START through negative feedback between Cln3-Cdk1 and Rim15/Greatwall kinase in budding yeast. eLife (2017).
4. Yeast Cip1 is activated by environmental stress to inhibit Cdk1–G1 cyclins via Mcm1 and Msn2/4. Nature Communications (2017).
5. Cdk1 activity acts as a quantitative platform for coordinating cell cycle progression with periodic transcription. Nature Communications (2016).
6. Multiple Layers of Phospho-Regulation Coordinate Metabolism and the Cell Cycle in Budding Yeast. Frontiers in Cell and Developmental Biology (2019).