Biomaterial Database

Molecular mechanisms creating bistable switches at cell cycle transitions. 2013

Anael Verdugo, and P K Vinod, and John J Tyson, and Bela Novak

Department of Biochemistry, University of Oxford, Oxford, UK.

Progression through the eukaryotic cell cycle is characterized by specific transitions, where cells move irreversibly from stage i-1 of the cycle into stage i. These irreversible cell cycle transitions are regulated by underlying bistable switches, which share some common features. An inhibitory protein stalls progression, and an activatory protein promotes progression. The inhibitor and activator are locked in a double-negative feedback loop, creating a one-way toggle switch that guarantees an irreversible commitment to move forward through the cell cycle, and it opposes regression from stage i to stage i-1. In many cases, the activator is an enzyme that modifies the inhibitor in multiple steps, whereas the hypo-modified inhibitor binds strongly to the activator and resists its enzymatic activity. These interactions are the basis of a reaction motif that provides a simple and generic account of many characteristic properties of cell cycle transitions. To demonstrate this assertion, we apply the motif in detail to the G1/S transition in budding yeast and to the mitotic checkpoint in mammalian cells. Variations of the motif might support irreversible cellular decision-making in other contexts.

UI	MeSH Term	Description	Entries
D007700	Kinetics	The rate dynamics in chemical or physical systems.
D008958	Models, Molecular	Models used experimentally or theoretically to study molecular shape, electronic properties, or interactions; includes analogous molecules, computer-generated graphics, and mechanical structures.	Molecular Models,Model, Molecular,Molecular Model
D002453	Cell Cycle	The complex series of phenomena, occurring between the end of one CELL DIVISION and the end of the next, by which cellular material is duplicated and then divided between two daughter cells. The cell cycle includes INTERPHASE, which includes G0 PHASE; G1 PHASE; S PHASE; and G2 PHASE, and CELL DIVISION PHASE.	Cell Division Cycle,Cell Cycles,Cell Division Cycles,Cycle, Cell,Cycle, Cell Division,Cycles, Cell,Cycles, Cell Division,Division Cycle, Cell,Division Cycles, Cell
D004798	Enzymes	Biological molecules that possess catalytic activity. They may occur naturally or be synthetically created. Enzymes are usually proteins, however CATALYTIC RNA and CATALYTIC DNA molecules have also been identified.	Biocatalyst,Enzyme,Biocatalysts
D012441	Saccharomyces cerevisiae	A species of the genus SACCHAROMYCES, family Saccharomycetaceae, order Saccharomycetales, known as "baker's" or "brewer's" yeast. The dried form is used as a dietary supplement.	Baker's Yeast,Brewer's Yeast,Candida robusta,S. cerevisiae,Saccharomyces capensis,Saccharomyces italicus,Saccharomyces oviformis,Saccharomyces uvarum var. melibiosus,Yeast, Baker's,Yeast, Brewer's,Baker Yeast,S cerevisiae,Baker's Yeasts,Yeast, Baker
D013379	Substrate Specificity	A characteristic feature of enzyme activity in relation to the kind of substrate on which the enzyme or catalytic molecule reacts.	Specificities, Substrate,Specificity, Substrate,Substrate Specificities
D016193	G1 Phase	The period of the CELL CYCLE preceding DNA REPLICATION in S PHASE. Subphases of G1 include "competence" (to respond to growth factors), G1a (entry into G1), G1b (progression), and G1c (assembly). Progression through the G1 subphases is effected by limiting growth factors, nutrients, or inhibitors.	First Gap Phase,G1a Phase,G1b Phase,Gap Phase 1,First Gap Phases,G1 Phases,G1a Phases,G1b Phases,Gap Phase, First,Gap Phases, First,Phase 1, Gap,Phase, First Gap,Phase, G1,Phase, G1a,Phase, G1b,Phases, First Gap,Phases, G1,Phases, G1a,Phases, G1b
D050756	Cyclin-Dependent Kinase Inhibitor Proteins	A group of cell cycle proteins that negatively regulate the activity of CYCLIN/CYCLIN-DEPENDENT KINASE complexes. They inhibit CELL CYCLE progression and help control CELL PROLIFERATION following GENOTOXIC STRESS as well as during CELL DIFFERENTIATION.	CIP-KIP Cyclin-Dependent Kinase Inhibitors,INK4 Cyclin-Dependent Kinase Inhibitors,CDKI Proteins,CIP-KIP CDKI Proteins,CIP-KIP CKI Proteins,CKI Proteins,Cyclin-Kinase Inhibitor Proteins,INK4 CDKI Proteins,INK4 CKI Proteins,Inhibitors of Cyclin-Dependent Kinase 4 Proteins,CDKI Proteins, CIP-KIP,CDKI Proteins, INK4,CIP KIP CDKI Proteins,CIP KIP CKI Proteins,CIP KIP Cyclin Dependent Kinase Inhibitors,CKI Proteins, CIP-KIP,CKI Proteins, INK4,Cyclin Dependent Kinase Inhibitor Proteins,Cyclin Kinase Inhibitor Proteins,INK4 Cyclin Dependent Kinase Inhibitors,Inhibitor Proteins, Cyclin-Kinase,Inhibitors of Cyclin Dependent Kinase 4 Proteins
D018844	Cyclin-Dependent Kinases	Protein kinases that control cell cycle progression in all eukaryotes and require physical association with CYCLINS to achieve full enzymatic activity. Cyclin-dependent kinases are regulated by phosphorylation and dephosphorylation events.	Cyclin-Dependent Kinase,Cyclin-Dependent Protein Kinase,cdk Proteins,Cyclin-Dependent Protein Kinases,Cyclin Dependent Kinase,Cyclin Dependent Kinases,Cyclin Dependent Protein Kinase,Cyclin Dependent Protein Kinases,Kinase, Cyclin-Dependent,Kinase, Cyclin-Dependent Protein,Protein Kinase, Cyclin-Dependent