Functional oscillation of a multienzyme glucosome assembly during cell cycle progression

Abstract

Glucose metabolism has been studied extensively to understand functional interplays between metabolism and a cell cycle. However, our understanding of cell cycle-dependent metabolic adaptation particularly in human cells remains largely elusive. Meanwhile, human enzymes in glucose metabolism are shown to functionally organize into three different sizes of a multienzyme metabolic assembly, the glucosome, to regulate glucose flux in a size-dependent manner. Here, using fluorescence single-cell imaging techniques, we discover that glucosomes spatiotemporally oscillate during a cell cycle in an assembly size-dependent manner. Importantly, their oscillation at single-cell levels is in accordance with functional contributions of glucose metabolism to cell cycle progression at a population level. Collectively, we demonstrate functional oscillation of glucosomes during cell cycle progression and thus their biological significance to human cell biology.

Mechanistic insights of glucosome condensate formation by stochastic modeling approaches

“…Collectively, we demonstrate that the biological properties of PFKL which would be intrinsically under controls by various cellular processes, including but not limited to signaling pathways (Jeon et al, 2022a) and a cell cycle (Jeon et al, 2022b), are critical determinants at the initiation step for glucosome formation in human cells.…”

“…Collectively, we identified in silico several biologically relevant parameters of PFKL (i.e., its intermolecular interaction strength, its effective concentration, its multivalency, and its pre-organization prior to condensate formation) that would regulate the formation of PFKL condensates and their sizes in cells. Accordingly, we propose that, when the scaffolder enzyme of a multienzyme glucosome condensate, PFKL, is subcellularly controlled to present relatively a stronger interaction or a higher effective concentration, regulated to be located in a higher multivalency mimicking environment, or organized to form filamentous or similar structures in a cell, the formation of glucosome condensates would be promoted to orchestrate glucose flux in conjunction with other cellular processes in human cells (Jeon et al ., 2022a; Jeon et al ., 2018; Jeon et al ., 2022b; Kennedy et al ., 2022; Kohnhorst et al ., 2017). Considering our study was done in silico with stochastic modeling approaches, we offer a possibility that any metabolic enzymes might be able to form spatially resolved condensates, but at different degrees, in human cells particularly when their biological and physical properties are perturbed acutely and/or dysregulated chronically in human cells.…”

“…This is indeed consistent with what we have observed in living human cells (Kennedy et al ., 2022; Kohnhorst et al ., 2017), where two populations of PFKLs (i.e., inside and outside a condensate) often coexist depending on subcellular environment or available exogenous stimuli where enzymatic properties of PFKL are regulated. Collectively, we demonstrate that the biological properties of PFKL which would be intrinsically under controls by various cellular processes, including but not limited to signaling pathways (Jeon et al ., 2022a) and a cell cycle (Jeon et al ., 2022b), are critical determinants at the initiation step for glucosome formation in human cells.…”

“…Then, when more than 9 PFKL tetramers were assembled during our MD simulation, we counted it as a condensate because 3-8 PFKL tetramers were shown to form filaments in vitro (Webb et al ., 2017). Next, to determine our simulation time, we considered two facts; (i) that LLPS has been reported to occur in the time scale of several seconds to minutes (Dundr et al, 2004; Phair and Misteli, 2000; Weidtkamp-Peters et al, 2008) and also (ii) that PFKL condensates have been experimentally shown to form within minutes to several hours after addition of exogenous cues (Jeon et al, 2022a; Jeon et al ., 2018; Jeon et al, 2022b; Kennedy et al ., 2022; Kohnhorst et al ., 2017). After careful evaluation of various simulation times ranging from 15 to 60 minutes, we decided to run our MD simulations for 30 minutes because it allowed us to robustly evaluate whether a given set of input parameters would promote the formation of PFKL condensates or not.…”

High-content quantitative high-throughput screening identifies a cell cycle-associated signaling cascade that regulates a multienzyme metabolic assembly for glucose metabolism

“…At the same time, interactions between cyclin dependent kinases (CDKs) and their associated cyclins are essential to regulate subcellular locations, expression levels, and/or enzymatic activities of glycolytic enzymes, including PFK1 and pyruvate kinase muscle isoform 2, for cell cycle progression (10,(12)(13)(14). Importantly, we have recently revealed that multienzyme glucosome assemblies, that regulates glucose flux at subcellular levels (4,5,15), dynamically oscillate in space and time during a cell cycle (16). However, it has remained elusive which regulatory mechanisms ensure tight control over glucosome assemblies and their dynamics during cell cycle progression.…”