scholarly journals The oscillation of mitotic kinase governs cell cycle latches

2021 ◽  
Author(s):  
Bela Novak ◽  
John J Tyson
Keyword(s):  
Cell Cycle ◽  
Negative Feedback ◽  
Molecular Switches ◽  
Feedback Loops ◽  
Yeast Cells ◽  
Cyclin Dependent Kinases ◽  
Mitotic Kinase ◽  
Daughter Cells ◽  
Negative Feedback Loops ◽  
A Cell

SummaryIn order to transmit a eukaryotic cell’s genome accurately from mother cell to daughter cells, it is essential that the basic events of the cell division cycle (DNA synthesis and mitosis) occur once and only once per cycle, i.e., that a cell progresses irreversibly from G1 to S to G2 to M and back to G1. Irreversible progression through the cell cycle is assured by a sequence of ‘latching’ molecular switches, based on molecular interactions among cyclin-dependent kinases and their auxiliary partners. Positive feedback loops (++ or −−) create bistable switches with latching properties, and negative feedback loops drive progression from one stage to the next. In budding yeast (Saccharomyces cerevisiae) these events are coordinated by double-negative feedback loops between Clb-dependent kinases (Clb1-6) and their antagonists (APC:Cdh1 and Sic1). If the coordinating signal is compromised, either by deletion of Clb1-5 proteins or expression of non-degradable Clb2, then irreversibility is lost and yeast cells exhibit multiple rounds of DNA replication or mitotic exit events (Cdc14 endocycles). Using mathematical modelling of a stripped-down control network, we show how endocycles arise because the switches fail to latch, and the gates swing back and forth by the action of the negative feedback loops.

Delay model of circadian gene expression with two negative feedback loops

2006 ◽  
Vol 37 (5) ◽  
pp. 405-417
Author(s):  
Andreas Bohn ◽  
José R. Lopes ◽  
Luís A. Diambra ◽  
Luiz S. Menna-Barreto
Keyword(s):  
Gene Expression ◽  
Negative Feedback ◽  
Feedback Loops ◽  
Delay Model ◽  
Circadian Gene ◽  
Negative Feedback Loops

Three proteins required for early steps in the protein secretory pathway also affect nuclear envelope structure and cell cycle progression in fission yeast

2002 ◽  
Vol 115 (2) ◽  
pp. 421-431
Author(s):  
Anna Matynia ◽  
Sandra S. Salus ◽  
Shelley Sazer
Keyword(s):  
Cell Cycle ◽  
Nuclear Envelope ◽  
Fission Yeast ◽  
Cell Cycle Progression ◽  
Secretory Pathway ◽  
Yeast Cells ◽  
Ran Gtpase ◽  
A Cell ◽  
Cell Cycle Block ◽  
Er Membrane

The Ran GTPase is an essential protein that has multiple functions in eukaryotic cells. Fission yeast cells in which Ran is misregulated arrest after mitosis with condensed, unreplicated chromosomes and abnormal nuclear envelopes. The fission yeast sns mutants arrest with a similar cell cycle block and interact genetically with the Ran system. sns-A10, sns-B2 and sns-B9 have mutations in the fission yeast homologues of S. cerevisiae Sar1p, Sec31p and Sec53p, respectively, which are required for the early steps of the protein secretory pathway. The three sns mutants accumulate a normally secreted protein in the endoplasmic reticulum (ER), have an increased amount of ER membrane, and the ER/nuclear envelope lumen is dilated. Neither a post-ER block in the secretory pathway, nor ER proliferation caused by overexpression of an integral ER membrane protein, results in a cell cycle-specific defect. Therefore, the arrest seen in sns-A10, sns-B2 and sns-B9 is most likely due to nuclear envelope defects that render the cells unable to re-establish the interphase organization of the nucleus after mitosis. As a consequence, these mutants are unable to decondense their chromosomes or to initiate of the next round of DNA replication.

scholarly journals Limit cycles in models of circular gene networks regulated by negative feedback loops

2020 ◽  
Vol 21 (S11) ◽  
Author(s):  
Vitaly A. Likhoshvai ◽  
Vladimir P. Golubyatnikov ◽  
Tamara M. Khlebodarova
Keyword(s):  
Negative Feedback ◽  
Gene Networks ◽  
Functional Organization ◽  
Molecular Genetic ◽  
Feedback Loops ◽  
System Structure ◽  
Signal Delay ◽  
Negative Feedback Loops ◽  
Regulatory Signal ◽  
Delay Phenomenon

Abstract Background The regulatory feedback loops that present in structural and functional organization of molecular-genetic systems and the phenomenon of the regulatory signal delay, a time period between the moment of signal reception and its implementation, provide natural conditions for complicated dynamic regimes in these systems. The delay phenomenon at the intracellular level is a consequence of the matrix principle of data transmission, implemented through the rather complex processes of transcription and translation.However, the rules of the influence of system structure on system dynamics are not clearly understood. Knowledge of these rules is particularly important for construction of synthetic gene networks with predetermined properties. Results We study dynamical properties of models of simplest circular gene networks regulated by negative feedback mechanisms. We have shown existence and stability of oscillating trajectories (cycles) in these models. Two algorithms of construction and localization of these cycles have been proposed. For one of these models, we have solved an inverse problem of parameters identification. Conclusions The modeling results demonstrate that non-stationary dynamics in the models of circular gene networks with negative feedback loops is achieved by a high degree of non-linearity of the mechanism of the autorepressor influence on its own expression, by the presence of regulatory signal delay, the value of which must exceed a certain critical value, and transcription/translation should be initiated from a sufficiently strong promoter/Shine-Dalgarno site. We believe that the identified patterns are key elements of the oscillating construction design.

scholarly journals Noise in transcription negative feedback loops: simulation and experimental analysis

2006 ◽  
Vol 2 (1) ◽  
pp. 41 ◽  
Author(s):  
Yann Dublanche ◽  
Konstantinos Michalodimitrakis ◽  
Nico Kümmerer ◽  
Mathilde Foglierini ◽  
Luis Serrano
Keyword(s):  
Negative Feedback ◽  
Experimental Analysis ◽  
Feedback Loops ◽  
Negative Feedback Loops
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