Subcellular regulation of glucose metabolism through multienzyme glucosome assemblies by EGF–ERK1/2 signaling pathways

Abstract

This is a PDF file of an article that has undergone enhancements after acceptance, such as the addition of a cover page and metadata, and formatting for readability, but it is not yet the definitive version of record. This version will undergo additional copyediting, typesetting and review before it is published in its final form, but we are providing this version to give early visibility of the article. Please note that, during the production process, errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.

Functional regulation of 4D metabolic network between multienzyme glucosome condensates and mitochondria

“…Previously, we have demonstrated that enzymes in glucose metabolism are spatially organized to form multienzyme glucosome assemblies in living human cells [7][8][9] . Depending on their sizes, glucosomes are capable of regulating glucose flux between glycolysis and building block biosynthesis at single cell levels in human cells.…”

“…3b) suggest a potential mechnaism by which glucosome condensates are specific to the enzymes that are involved in only glucose metabolism. To date, many metabolic enzymes have been visualized to form various mesocale structures in living cells or in vitro 8,[21][22][23][24][25] . Particularly, enzymes in de novo purine biosynthesis have been demonstrated to form spatially resolved and functionally active multienzyme assemblies in human cells (i.e., purinosomes 24 ).…”

“…In particular, we have discovered a multienzyme metabolic assembly, namely the "glucosome," that encapsulates several enzymes participating in human glucose metabolism 7 . Subsequently, we have shown that glucosomes are spatially organized into various sizes to functionally orchestrate glucose flux between mitochondrial metabolism and building block biosynthesis 7,8 . However, it has not been elucidated yet how glucosomes are spatially regulated by LLPS to functionally communicate with other membraneless and/or membrane-bound organelles in living cells.…”

“…In this work, we employed various live-cell imaging platforms, particularly including lattice light sheet microscopic (LLSM) imaging, along with other biophysical and biochemical techniques, to quantitatively understand a 4-dimensional (4D) network of glucose metabolism in living human cells. We first visualized glucosomes using a fusion protein of human liver-type phosphofructokinase (PFKL) with a monomeric enhanced green fluorescent protein (i.e., PFKL-mEGFP) because it has been implicated as a glucosome marker in living human cells [7][8][9] . We then found that glucosomes are organized and regulated by LLPS in live cells.…”

Mechanistic insights of glucosome condensate formation by stochastic modeling approaches

“…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.…”