KEY PUBLICATIONS

Alternative modes of client binding enable functional plasticity of Hsp70
Alireza Mashaghi et al. | Nature 539, 448-451 (2016) | pdf & DOI: 10.1038/nature20137
Stochasticity of metabolism and growth at the single-cell level
Daniel J. Kiviet et al. | Nature 514, 376-379 (2014) | pdf & DOI: 10.1038/nature13582
Reshaping of the conformational search of a protein by the chaperone trigger factor
Alireza Mashaghi et al. | Nature 500, 98-101 (2013) | pdf & DOI: 10.1038/nature12293
Tradeoffs and optimality in the evolution of gene regulation
Frank J. Poelwijk et al. | Cell 146, 462-470 (2011) | pdf & DOI:10.1016/j.cell.2011.06.035
Direct Observation of Chaperone-Induced Changes in a Protein Folding Pathway
Philipp Bechtluft, Ruud van Leeuwen et al. | Science 318:1458-1461 (2007) | pdf & DOI:10.1126/science.1144972
Empirical fitness landscapes reveal accessible evolutionary paths
Frank Poelwijk, Daan Kiviet et al. | Nature 445:383-386 (2007) | pdf & DOI:10.1038/nature05451
The bacteriophage phi29 portal motor can package DNA against a large internal force
Douglas E. Smith, Sander J. Tans et al. | Nature 413:748-52 (2001) | pdf & DOI:10.1038/35099581
Molecular transistors: Potential modulations along carbon nanotubes
Sander J. Tans, Cees Dekker. | Nature 404:834-35 (2000) | pdf & DOI:10.1038/35009026
Imaging electron wave functions of quantized energy levels in carbon nanotubes
Liesbeth C. Venema et al. | Science 283:52-55 (1999) | pdf & DOI:10.1126/science.283.5398.52
Electron-electron correlations in carbon nanotubes
Sander J. Tans et al. | Nature 394:761-64 (1998) | pdf & DOI:10.1038/29494
Room-temperature transistor based on a single carbon nanotube
Sander J. Tans, Alwin R. M. Verschueren & Cees Dekker | Nature 393:49-52 (1998) | pdf & DOI:10.1038/29954
Individual single-wall carbon nanotubes as quantum wires
Sander J. Tans et al. | Nature 386:474-77 (1997) | pdf & DOI:10.1038/386474a0
Fullerene 'crop circles'
Jie Liu et al. | Nature 385, 780-781 (1997) | pdf & DOI:10.1038/385780b0

Generation and filtering of gene expression noise by the bacterial cell cycle

Walker, N.; Nghe, P.; Tans, S. J.
Abstract:
Gene expression within cells is known to fluctuate stochastically in time. However, the origins of gene expression noise remain incompletely understood. The bacterial cell cycle has been suggested as one source, involving chromosome replication, exponential volume growth, and various other changes in cellular composition. Elucidating how these factors give rise to expression variations is important to models of cellular homeostasis, fidelity of signal transmission, and cell-fate decisions.\\ Using single-cell time-lapse microscopy, we measured cellular growth as well as fluctuations in the expression rate of a fluorescent protein and its concentration. We found that, within the population, the mean expression rate doubles throughout the cell cycle with a characteristic cell cycle phase dependent shape which is different for slow and fast growth rates. At low growth rate, we find the mean expression rate was initially flat, and then rose approximately linearly by a factor two until the end of the cell cycle. The mean concentration fluctuated at low amplitude with sinusoidal-like dependence on cell cycle phase. Traces of individual cells were consistent with a sudden two-fold increase in expression rate, together with other non-cell cycle noise. A model was used to relate the findings and to explain the cell cycle-induced variations for different chromosomal positions.\\ We found that the bacterial cell cycle contribution to expression noise consists of two parts: a deterministic oscillation in synchrony with the cell cycle and a stochastic component caused by variable timing of gene replication. Together, they cause half of the expression rate noise. Concentration fluctuations are partially suppressed by a noise cancelling mechanism that involves the exponential growth of cellular volume. A model explains how the functional form of the concentration oscillations depends on chromosome position.
Year:
2016
Type of Publication:
Article
Journal:
BMC Biol.
Volume:
14
Pages:
11
Month:
February
Note:
[PubMed Central:\href{https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4750204}{PMC4750204}] [DOI:\href{https://dx.doi.org/10.1186/s12915-016-0231-z}{10.1186/s12915-016-0231-z}] [PubMed:\href{https://www.ncbi.nlm.nih.gov/pubmed/26867568}{26867568}]
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