Hierarchy of feedbacks in biological oscillators: its impact in the characteristics of the oscillations

JUAN IGNACIO MARRONE; HERNÁN E. GRECCO; ALEJANDRA C. VENTURA

Puerto Madryn

Conferencia; Statistical Physics in Biological Networks; 2020

UNIVERSIDAD NACIONAL DE GENERAL SARMIENTO (UNGS); INTERNATIONAL CENTRE FOR THEORETICAL PHYSICS ; THE ABDUS SALAM

In a wide variety of cellular processes biological oscillations take place, among them in calcium signaling pathways and within gene regulatory networks, like the circadian system. In this work we study biological oscillators that involve a combination of positive and negative feedbacks. It is known that the oscillations that emerge from PNF systems are significantly different, in terms of the controllability of the frequency and the amplitude, from the oscillations in negative feedback systems. We will consider, among others, the case of the double phosphorylation of a protein, where the kinase is activated by an external stimulus. Double phosphorylation ensures bistability due to the presence of a positive feedback. The kinase activation generates a sequestration effect that results in a non-evident negative feedback. In this work we study how, by changing the hierarchy of the feedbacks in play, this signaling pathway can display different modes of oscillations, both the ones expected in PNF systems, and the oscillations found in NF systems.