New insight into molecular interactions throws open a ‘window to evolution’

The findings represented a blueprint for adaptation-capable signalling networks across all domains of life and for the design of synthetic biosystems

The study discovered fundamental molecular-level design principles that organised all forms of biological complexity into robustness-promoting, and ultimately, survival-promoting, chemical reaction structures. | Photo Credit: Getty Images/iStock

Mathematicians have uncovered details about the universal explanatory framework for molecular interactions that help them adapt to new and variable conditions while maintaining tight control over key survival properties.

Throwing open a "window to evolution", the researchers said, their findings represented a blueprint for adaptation-capable signalling networks across all domains of life and for the design of synthetic biosystems.

"Our study considers a process called robust perfect adaptation (RPA) whereby biological systems, from individual cells to entire organisms, maintain important molecules within narrow concentration ranges despite continually being bombarded with disturbances to the system," said Robyn Araujo, from Queensland University of Technology School of Mathematical Sciences, Australia, and corresponding author on the study.

The researchers said that they had discovered fundamental molecular-level design principles that organised all forms of biological complexity into robustness-promoting, and ultimately, survival-promoting, chemical reaction structures.

The study is published in the journal Nature Communications.

Araujo said they had found that molecules of living systems cannot simply 'transmit' biochemical signals but must make 'computations' on these signals.

"These complex intermolecular interactions must implement a special type of regulation known as integral control – a design strategy known to engineers for almost a century.

"However, signalling networks in nature are vastly different, having evolved to rely on the physical interactions between discrete molecules.

"So, nature's 'solutions' operate through remarkable and highly intricate collections of interactions, without engineering's specially designed, integral-computing components, and often without feedback loops.

"We show that molecular network structures use a form of integral control in which multiple independent integrals, each with a very special and simple structure, can collaborate to confer the capacity for adaptation on specific molecules.

"Using an algebraic algorithm based on this finding, we have been able to demonstrate the existence of embedded integrals in biologically important chemical reaction networks whose ability to exhibit adaptation could never before be explained by any systematic method," said Araujo.

"On the basis of this ground-breaking new research, RPA currently stands alone as a keystone biological response for which there now exists a universal explanatory framework.

"At a practical level, this discovery could provide a completely fresh approach to tackle grand challenges in personalized medicine such as cancer drug resistance, addiction, and autoimmune diseases," said Lance Liotta, study author.