Synopsis: Biological Oscillations Improve Fidelity

Calculations show that a time-varying molecular input signal can induce a more predictable biological response than a constant input.

The complex molecular networks that underlie biological systems often show time variation, such as oscillations or pulses in the concentrations of various chemicals, but it is not always clear how this variation is useful. Writing in Physical Review Letters, researchers show that, in one biology-inspired model, the response to a time-varying input can reflect the average conditions more reliably than the response to a steady input does.

An important mechanism for regulating cellular activity is the reversible binding of a molecule, called a transcription factor, to a “promoter” region of the DNA, which prods a nearby gene into producing its corresponding protein. Filipe Tostevin and colleagues at the FOM Institute for Atomic and Molecular Physics (AMOLF) in Amsterdam, Netherlands, explored how a mathematical model of this process responds to a time-varying transcription-factor “input.” Such time variation of molecular concentrations often occurs in cells as the result of nonlinear feedback between the activities of various genes.

Even if the concentration of transcription factor is constant, the stochastic nature of the molecular processes, such as transcription-factor binding and unbinding, cause the output of protein to vary with time. The researchers found that this variation can be reduced when the transcription factor appears in repetitive pulses, because a strong pulse virtually guarantees that it will bind to the promoter at a particular time. The improved output variability with pulses occurs for a wide range of the response-time parameters in the model, including values that are similar to those measured in biological systems. – Don Monroe


Announcements

More Announcements »

Subject Areas

Biological Physics

Previous Synopsis

Atomic and Molecular Physics

Molecular Speed Bump

Read More »

Next Synopsis

Plasma Physics

Watch Those Cavities

Read More »

Related Articles

Synopsis: Maintaining the Sequence
Biological Physics

Synopsis: Maintaining the Sequence

Theoretical calculations indicate that an electrospray-based technique could correctly read out the amino acid sequence of protein molecules. Read More »

Synopsis: Neutron Stars in a Petri Dish
Nuclear Physics

Synopsis: Neutron Stars in a Petri Dish

Simulations of the dense matter in a neutron star’s crust predict the formation of structures that resemble those found in biological membranes. Read More »

Focus: Evolution Thins Out Distracting DNA
Biological Physics

Focus: Evolution Thins Out Distracting DNA

Proteins sometimes bind to the wrong stretch of DNA, but these "imposter" DNA sequences are statistically rare in many genomes, suggesting that evolution works against them. Read More »

More Articles