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

JUAN IGNACIO MARRONE; HERNAN GRECCO; ALEJANDRA C VENTURA

Puerto Madryn

Workshop; Workshop Statistical physics in biological networks; 2020

General Sarmiento National University

In a wide variety ofcellular processes biological oscillations take place, among them in calciumsignaling pathways and within gene regulatory networks, like the circadiansystem. In this work we study biological oscillators that involve a combinationof positive and negative feedbacks (PNF). It is known that the oscillationsthat emerge from PNF systems are significantly different, in terms of thecontrollability of the frequency and the amplitude, from the oscillations innegative feedback systems (NF). We will consider, among others, the case of thedouble phosphorylation of a protein, where the kinase is activated by anexternal stimulus [4]. Double phosphorylation ensures bistability due to thepresence of a positive feedback [5]. The kinase activation generates asequestration effect that results in a non-evident negative feedback [6]. Inthis work we study how, by changing the hierarchy of the feedbacks in play,this signaling pathway can display different modes of oscillations: both theones expected in PNF systems, and the oscillations found in NF systems.