Redundancy principle and the role of extreme statistics in molecular and cellular biology

Publication date: Available online 11 January 2019Source: Physics of Life ReviewsAuthor(s): Z. Schuss, K. Basnayake, D. HolcmanAbstractThe paradigm of chemical activation rates in cellular biology has been shifted from the mean arrival time of a single particle to the mean of the first among many particles to arrive at a small activation site. The activation rate is set by extremely rare events, which are often much different from the mean times between activations and depend on different structural parameters. This shift calls for reconsideration of physical processes used in deterministic and stochastic modeling of chemical reactions that are based on the traditional forward rate, especially for fast activation processes in living cells. Consequently, the biological activation time is not necessarily exponentially distributed. We review here the physical models, the mathematical analysis and the new paradigm, of setting the scale to be the shortest time to activation that clarifies the role of population redundancy in selecting and accelerating transient cellular search processes. This is the case, for example, in cellular transduction, gene activation, cell senescence activation or spermatozoa selection during fertilization, where the rate depends on numbers. We conclude that the statistics of the minimal time to activation set the kinetics laws in biology, which can be very different from the ones associated to average times.

Source: Physics of Life Reviews - January 11, 2019 Category: Physics Source Type: research