Cellular Adaptation Relies on Regulatory Proteins Having Episodic Memory

Abstract

The ability to memorize changes in the environment is present at all biological levels, from social groups and individuals, down to single cells. Trans-generational memory is embedded subcellularly through genetic and epigenetic mechanisms. Evidence that cells process and remember features of the immediate environment using protein sensors is reviewed. It is argued that this mnemonic ability is encapsulated within the protein conformational space and lasts throughout its lifetime, which can overlap with the lifespan of the organism. Means to determine diachronic changes in protein activity are presented. Molecular Memory Features in Single Proteins and in Protein ComplexesCells must encode data regarding fluctuations in the internal and external milieu, in order to compute appropriate responses and optimize energy use. Complex cellular signaling pathways are present for sensing and remembering features of the environment, endowing even prokaryotes with a "bacterial IQ." [1] To this end, a basic form of short-term memory for relevant stimuli is already present at the level of cellular membranes. Fluctuations in membrane fluidity upon electroporation with subsequent clamping of applied voltage present a self-sustained temporary equilibrium between opening and resealing processes. [2,3] The information content these structures hold through sustained conformational changes is limited, compared to the number of conformational changes that proteins possess. [4] We define protein memory as the time-dependent buffering capacity against stochastic fluctuations of stimuli, enabling proteins to adjust

Monomeric Esterase: Insights into Cooperative Behavior, Hysteresis/Allokairy

“…Hysteresis may be caused by substrate, solvent, pH, or applied voltage − (Table S1). − In addition, hysteretic enzymes play an important role in the regulation of metabolic pathways under particular physiological conditions ,,,, coupling enzymatic activity to the oscillation of a metabolite concentration. − For instance, the loss of the cooperativity of the monomeric human glucokinase (GCK) impacts glucose homeostasis . GCK plays a crucial role in glucose metabolism in the pancreas and liver by catalyzing the ATP-dependent phosphorylation of glucose to glucose-6-phosphate, a pivotal step in glucose metabolism.…”

Defining Network Topologies that Can Achieve Molecular Memory

“…In the context of cellular signaling and gene regulatory networks, there is an increasing evidence that memory can be a key determinant factor underlying molecular mechanisms (1)(2)(3)(4) (5)(6)(7)(8). In these papers, cellular systems are first treated with priming inputs followed by a time window and then the stimuli.…”

Molecular and functional basis of a novel Amazonian Dark Earth Esterase 1 (Ade1) with hysteresis behavior and quorum-quenching activity

“…In contrast, the presence of substrate changes the equilibrium constant of the structural conformation states. In addition, the LIST behavior can be caused not only by the substrate but also by the solvent nature, pH, or applied voltage [34][35][36] . Hysteresis is fundamental to understanding the system's biology because its enzymatic profile can control activation or inhibition of a biological pathway using only one enzyme 37 .…”

“…Hysteresis is fundamental to understanding the system's biology because its enzymatic profile can control activation or inhibition of a biological pathway using only one enzyme 37 . One example of that is the modulation of the enzymatic activity based on the oscillation of a metabolic pathway benefiting the cell [34][35][36] .…”