Lysosomal Glycosphingolipid Storage Diseases.

Glycosphingolipids are cell-type-specific components of the outer leaflet of mammalian plasma membranes. Gangliosides, sialic acid-containing glycosphingolipids, are especially enriched on neuronal surfaces. As amphi-philic molecules, they comprise a hydrophilic oligosaccharide chain attached to a hydrophobic membrane anchor, ceramide. Whereas glycosphingolipid formation is catalyzed by membrane-bound enzymes along the secretory pathway, degradation takes place at the surface of intralysosomal vesicles of late endosomes and lysosomes catalyzed in a stepwise fashion by soluble hydrolases and assisted by small lipid-binding glycoproteins. Inherited defects of lysosomal hydrolases or lipid-binding proteins cause the accumulation of undegradable material in lysosomal storage diseases (GM1 and GM2 gangliosidosis; Fabry, Gaucher, and Krabbe diseases; and metachromatic leukodystrophy). The catabolic processes are strongly modified by the lipid composition of the substrate-carrying membranes, and the pathological accumulation of primary storage compounds can trigger an accumulation of secondary storage compounds (e.g., small glycosphingolipids and cholesterol in Niemann-Pick disease).

Structure, biogenesis and evolution of thylakoid membranes.

Cyanobacteria and chloroplasts of algae and plants harbor specialized thylakoid membranes that convert sunlight into chemical energy. These membranes house photosystems II and I, the vital protein-pigment complexes that drive oxygenic photosynthesis. In the course of their evolution, thylakoid membranes have diversified in structure. However, the core machinery for photosynthetic electron transport remained largely unchanged, with adaptations occurring primarily in the light-harvesting antenna systems. Whereas thylakoid membranes in cyanobacteria are relatively simple they become more complex in algae and plants. The chloroplasts of vascular plants contain intricate networks of stacked grana and unstacked stroma thylakoids. This review provides an in-depth view of thylakoid membrane architectures in phototrophs, and the determinants that shape their forms, as well as presenting recent insights into the spatial organization of their biogenesis and maintenance. Its overall goal is to define the underlying principles that have guided the evolution of these bioenergetic membranes.

Endoplasmic reticulum stress controls PIN-LIKES abundance and thereby growth adaptation.

Extreme environmental conditions eventually limit plant growth [J. R. Dinneny, Annu. Rev. Cell Dev. Biol. 35, 1-19 (2019), N. Gigli-Bisceglia, C. Testerink, Curr. Opin. Plant Biol. 64, 102120 (2021)]. Here, we reveal a mechanism that enables multiple external cues to get integrated into auxin-dependent growth programs in Arabidopsis thaliana. Our forward genetics approach on dark-grown hypocotyls uncovered that an imbalance in membrane lipids enhances the protein abundance of PIN-LIKES (PILS) [E. Barbez et al., Nature 485, 119 (2012)] auxin transport facilitators at the endoplasmic reticulum (ER), which thereby limits nuclear auxin signaling and growth rates. We show that this subcellular response relates to ER stress signaling, which directly impacts PILS protein turnover in a tissue-dependent manner. This mechanism allows PILS proteins to integrate environmental input with phytohormone auxin signaling, contributing to stress-induced growth adaptation in plants.

Membrane Lipids Augment Cell Envelope Stress Signaling via the MadRS System to Defend Against Antimicrobial Peptides and Antibiotics in Enterococcus faecalis.

Enterococci have evolved resistance mechanisms to protect their cell envelopes against bacteriocins and host cationic antimicrobial peptides (CAMPs) produced in the gastrointestinal environment. Activation of the membrane stress response has also been tied to resistance to the lipopeptide antibiotic daptomycin. However, the actual effectors mediating resistance have not been elucidated. Here, we show that the MadRS (formerly YxdJK) membrane antimicrobial peptide defense system controls a network of genes, including a previously uncharacterized three gene operon (madEFG) that protects the E. faecalis cell envelope from antimicrobial peptides. Constitutive activation of the system confers protection against CAMPs and daptomycin in the absence of a functional LiaFSR system and leads to persistence of cardiac microlesions in vivo. Moreover, changes in the lipid cell membrane environment alter CAMP susceptibility and expression of the MadRS system. Thus, we provide a framework supporting a multilayered envelope defense mechanism for resistance and survival coupled to virulence.

DesC1 and DesC2, Δ9 Fatty Acid Desaturases of Filamentous Cyanobacteria: Essentiality and Complementarity.

DesC1 and DesC2, which are fatty acid desaturases found in cyanobacteria, are responsible for introducing a double bond at the Δ9 position of fatty-acyl chains, which are subsequently esterified to the sn-1 and sn-2 positions of the glycerol moiety, respectively. However, since the discovery of these two desaturases in the Antarctic cyanobacterium Nostoc sp. SO-36, no further research has been reported. This study presents a comprehensive characterization of DesC1 and DesC2 through targeted mutagenesis and transformation using two cyanobacteria strains: Anabaena sp. PCC 7120, comprising both desaturases, and Synechocystis sp. PCC 6803, containing a single Δ9 desaturase (hereafter referred to as DesCs) sharing similarity with DesC1 in amino acid sequence. The results suggested that both DesC1 and DesC2 were essential in Anabaena sp. PCC 7120 and that DesC1, but not DesC2, complemented DesCs in Synechocystis sp. PCC 6803. In addition, DesC2 from Anabaena sp. PCC 7120 desaturated fatty acids esterified to the sn-2 position of the glycerol moiety in Synechocystis sp. PCC 6803.

Lipid mediated plant immunity in susceptible and tolerant soybean cultivars in response to Phytophthora sojae colonization and infection.

BACKGROUND: Soybean is one of the most cultivated crops globally and a staple food for much of the world's population. The annual global crop losses due to infection by Phytophthora sojae is currently estimated at $20B USD, yet we have limited understanding of the role of lipid mediators in the adaptative strategies used by the host plant to limit infection. Since root is the initial site of this infection, we examined the infection process in soybean root infected with Phytophthora sojae using scanning electron microscopy to observe the changes in root morphology and a multi-modal lipidomics approach to investigate how soybean cultivars remodel their lipid mediators to successfully limit infection by Phytophthora sojae. RESULTS: The results reveal the presence of elevated biogenic crystals and more severe damaged cells in the root morphology of the infected susceptible cultivar compared to the infected tolerant cultivars. Furthermore, induced accumulation of stigmasterol was observed in the susceptible cultivar whereas, induced accumulation of phospholipids and glycerolipids occurred in tolerant cultivar. CONCLUSION: The altered lipidome reported in this study suggest diacylglycerol and phosphatidic acid mediated lipid signalling impacting phytosterol anabolism appears to be a strategy used by tolerant soybean cultivars to successfully limit infection and colonization by Phytophthora sojae.

Bacterial Glycolipid Acting on Protein Transport Across Membranes.

The process of protein transport across membranes involves a variety of factors and has been extensively investigated. Traditionally, proteinaceous translocons and chaperones have been recognized as crucial factors in this process. However, recent studies have highlighted the significant roles played by lipids and a glycolipid present in biological membranes in membrane protein transport. Membrane lipids can influence transport efficiency by altering the physicochemical properties of membranes. Notably, our studies have revealed that diacylglycerol (DAG) attenuates mobility in the membrane core region, leading to a dramatic suppression of membrane protein integration. Conversely, a glycolipid in Escherichia coli inner membranes, named membrane protein integrase (MPIase), enhances integration not only through the alteration of membrane properties but also via direct interactions with membrane proteins. This review explores the mechanisms of membrane protein integration mediated by membrane lipids, specifically DAG, and MPIase. Our results, along with the employed physicochemical analysis methods such as fluorescence measurements, nuclear magnetic resonance, surface plasmon resonance, and docking simulation, are presented to elucidate these mechanisms.

OsKASI-2 is required for the regulation of unsaturation levels of membrane lipids and chilling tolerance in rice.

Chilling stress has seriously limited the global production and geographical distribution of rice. However, the molecular mechanisms associated with plant responses to chilling stress are less known. In this study, we revealed a member of ß-ketoacyl-ACP synthase I family (KASI), OsKASI-2 which confers chilling tolerance in rice. OsKASI-2 encodes a chloroplast-localized KASI enzyme mainly expressed in the leaves and anthers of rice and strongly induced by chilling stress. Disruption of OsKASI-2 led to decreased KAS enzymatic activity and the levels of unsaturated fatty acids, which impairs degree of unsaturation of membrane lipids, thus increased sensitivity to chilling stress in rice. However, the overexpression of OsKASI-2 significantly improved the chilling tolerance ability in rice. In addition, OsKASI-2 may regulate ROS metabolism in response to chilling stress. Natural variation of OsKASI-2 might result in difference in chilling tolerance between indica and japonica accessions, and Hap1 of OsKASI-2 confers chilling tolerance in rice. Taken together, we suggest OsKASI-2 is critical for regulating degree of unsaturation of membrane lipids and ROS accumulation for maintenance of membrane structural homeostasis under chilling stress, and provide a potential target gene for improving chilling tolerance of rice.

Testing quantitative magnetization transfer models with membrane lipids.

PURPOSE: Quantitative magnetization transfer (qMT) models aim to quantify the contributions of lipids and macromolecules to the MRI signal. Hence, a model system that relates qMT parameters and their molecular sources may improve the interpretation of the qMT parameters. Here we used membrane lipid phantoms as a meaningful tool to study qMT models. By controlling the fraction and type of membrane lipids, we could test the accuracy, reliability, and interpretability of different qMT models. METHODS: We formulated liposomes with various lipid types and water-to-lipids fractions and measured their signals with spoiled gradient-echo MT. We fitted three known qMT models and estimated six parameters for every model. We tested the accuracy and reproducibility of the models and compared the dependency among the qMT parameters. We compared the samples' qMT parameters with their water-to-lipid fractions and with a simple MTnorm (= MTon/MToff) calculation. RESULTS: We found that the three qMT models fit the membrane lipids signals well. We also found that the estimated qMT parameters are highly interdependent. Interestingly, the estimated qMT parameters are a function of the membrane lipid type and also highly related to the water-to-lipid fraction. Finally, we find that most of the lipid sample's information can be captured using the common and easy to estimate MTnorm analysis. CONCLUSION: qMT parameters are sensitive to both the water-to-lipid fraction and to the lipid type. Estimating the water-to-lipid fraction can improve the characterization of membrane lipids' contributions to qMT parameters. Similar characterizations can be obtained using the MTnorm analysis.

Constraining activity and growth substrate of fungal decomposers via assimilation patterns of inorganic carbon and water into lipid biomarkers.

Fungi are among the few organisms on the planet that can metabolize recalcitrant carbon (C) but are also known to access recently produced plant photosynthate. Therefore, improved quantification of growth and substrate utilization by different fungal ecotypes will help to define the rates and controls of fungal production, the cycling of soil organic matter, and thus the C storage and CO2 buffering capacity in soil ecosystems. This pure-culture study of fungal isolates combined a dual stable isotope probing (SIP) approach, together with rapid analysis by tandem pyrolysis-gas chromatography-isotope ratio mass spectrometry to determine the patterns of water-derived hydrogen (H) and inorganic C assimilated into lipid biomarkers of heterotrophic fungi as a function of C substrate. The water H assimilation factor (αW) and the inorganic C assimilation into C18:2 fatty acid isolated from five fungal species growing on glucose was lower (0.62% ± 0.01% and 4.7% ± 1.6%, respectively) than for species grown on glutamic acid (0.90% ± 0.02% and 7.4% ± 3.7%, respectively). Furthermore, the assimilation ratio (RIC/αW) for growth on glucose and glutamic acid can distinguish between these two metabolic modes. This dual-SIP assay thus delivers estimates of fungal activity and may help to delineate the predominant substrates that are respired among a matrix of compounds found in natural environments.IMPORTANCEFungal decomposers play important roles in food webs and nutrient cycling because they can feed on both labile and more recalcitrant forms of carbon. This study developed and applied a dual stable isotope assay (13C-dissolved inorganic carbon/2H) to improve the investigation of fungal activity in the environment. By determining the incorporation patterns of hydrogen and carbon into fungal lipids, this assay delivers estimates of fungal activity and the different metabolic pathways that they employ in ecological and environmental systems.

Two plastidial lysophosphatidic acid acyltransferases differentially mediate the biosynthesis of membrane lipids and triacylglycerols in Phaeodactylum tricornutum.

Lysophosphatidic acid acyltransferases (LPAATs) catalyze the formation of phosphatidic acid (PA), a central metabolite in both prokaryotic and eukaryotic organisms for glycerolipid biosynthesis. Phaeodactylum tricornutum contains at least two plastid-localized LPAATs (ptATS2a and ptATS2b), but their roles in lipid synthesis remain unknown. Both ptATS2a and ptATS2b could complement the high temperature sensitivity of the bacterial plsC mutant deficient in LPAAT. In vitro enzyme assays showed that they prefer lysophosphatidic acid over other lysophospholipids. ptATS2a is localized in the plastid inner envelope membrane and CRISPR/Cas9-generated ptATS2a mutants showed compromised cell growth, significantly changed plastid and extra-plastidial membrane lipids at nitrogen-replete condition and reduced triacylglycerols (TAGs) under nitrogen-depleted condition. ptATS2b is localized in thylakoid membranes and its knockout led to reduced growth rate and TAG content but slightly altered molecular composition of membrane lipids. The changes in glycerolipid profiles are consistent with the role of both LPAATs in the sn-2 acylation of sn-1-acyl-glycerol-3-phosphate substrates harboring 20:5 at the sn-1 position. Our findings suggest that both LPAATs are important for membrane lipids and TAG biosynthesis in P. tricornutum and further highlight that 20:5-Lyso-PA is likely involved in the massive import of 20:5 back to the plastid to feed plastid glycerolipid syntheses.

Annexin A2 modulates phospholipid membrane composition upstream of Arp2 to control angiogenic sprout initiation.

The intersection of protein and lipid biology is of growing importance for understanding how cells address structural challenges during adhesion and migration. While protein complexes engaged with the cytoskeleton play a vital role, support from the phospholipid membrane is crucial for directing localization and assembly of key protein complexes. During angiogenesis, dramatic cellular remodeling is necessary for endothelial cells to shift from a stable monolayer to invasive structures. However, the molecular dynamics between lipids and proteins during endothelial invasion are not defined. Here, we utilized cell culture, immunofluorescence, and lipidomic analyses to identify a novel role for the membrane binding protein Annexin A2 (ANXA2) in modulating the composition of specific membrane lipids necessary for cortical F-actin organization and adherens junction stabilization. In the absence of ANXA2, there is disorganized cortical F-actin, reduced junctional Arp2, excess sprout initiation, and ultimately failed sprout maturation. Furthermore, we observed reduced filipin III labeling of membrane cholesterol in cells with reduced ANXA2, suggesting there is an alteration in phospholipid membrane dynamics. Lipidomic analyses revealed that 42 lipid species were altered with loss of ANXA2, including an accumulation of phosphatidylcholine (16:0_16:0). We found that supplementation of phosphatidylcholine (16:0_16:0) in wild-type endothelial cells mimicked the ANXA2 knock-down phenotype, indicating that ANXA2 regulated the phospholipid membrane upstream of Arp2 recruitment and organization of cortical F-actin. Altogether, these data indicate a novel role for ANXA2 in coordinating events at endothelial junctions needed to initiate sprouting and show that proper lipid modulation is a critical component of these events.

Mitochondrial functions and fatty acid profiles in fish heart: an insight into physiological limitations linked with thermal tolerance and age.

Heart failure is among the first major consequences of heat stress in aquatic ectotherms. Mitochondria produce most of the ATP used by the heart and represent almost half of the volume in cardiac cells. It has therefore been hypothesized that mitochondrial dysfunctions may be highly involved in heart failure associated with heat stress. The present study aims to investigate if CTmax is linked to the thermal sensitivity of three-spined sticklebacks' (G. aculeatus) cardiac mitochondria, and if it is influenced by heart fatty acid composition and age. To do so, we measured the CTmax of 30 fish. The cardiac mitochondrial oxygen consumption was measured by high resolution respirometry at three temperatures and heart lipid profiles were obtained by Gas chromatography (GC) coupled with a Flame Ionization Detector (FID). Fish age was estimated via otolith readings. Fatty acid profiles showed no correlation with CTmax, but EPA levels were higher in older individuals. Mitochondrial respiration was measured in 35 fish using high resolution respirometry. It was strongly affected by temperature and showed a drastic drop in OXPHOS respiration fed by Complex I and Complex I+II, while uncoupled respiration plateaued at CTmax temperature. Our results suggest that Complex I is an important modulator of the impact of temperature on mitochondrial respiration at high temperatures but is not the main limiting factor in physiological conditions (maximal OXPHOS). Mitochondrial respiration was also affected by fish age, showing a general decrease in older individuals.

Cyclic tachyplesin I kills proliferative, non-proliferative and drug-resistant melanoma cells without inducing resistance.

Acquired drug resistance is the major cause for disease recurrence in cancer patients, and this is particularly true for patients with metastatic melanoma that carry a BRAF V600E mutation. To address this problem, we investigated cyclic membrane-active peptides as an alternative therapeutic modality to kill drug-tolerant and resistant melanoma cells to avoid acquired drug resistance. We selected two stable cyclic peptides (cTI and cGm), previously shown to have anti-melanoma properties, and compared them with dabrafenib, a drug used to treat cancer patients with the BRAF V600E mutation. The peptides act via a fast membrane-permeabilizing mechanism and kill metastatic melanoma cells that are sensitive, tolerant, or resistant to dabrafenib. Melanoma cells do not become resistant to long-term treatment with cTI, nor do they evolve their lipid membrane composition, as measured by lipidomic and proteomic studies. In vivo studies in mice demonstrated that the combination treatment of cTI and dabrafenib resulted in fewer metastases and improved overall survival. Such cyclic membrane-active peptides are thus well suited as templates to design new anticancer therapeutic strategies.

Polyunsaturated triacylglycerol accumulation mainly attributes to turnover of de novo-synthesized membrane lipids in stress-induced starchless Chlamydomonas.

KEY MESSAGE: Assembly of PUFA-attached TAGs is intimately correlated to turnover of newly formed membrane lipids in starch-deficient Chlamydomonas exposed to high light and nitrogen stress under air-aerated mixotrophic conditions. Triacylglycerols (TAGs) rich in polyunsaturated fatty acids (PUFAs) in microalgae have attracted extensive attention due to its promising application in nutraceuticals and other high-value compounds. Previous studies revealed that PUFAs accumulated in TAG primarily derived from the dominant membrane lipids, monogalactosyldiacylglycerolipid, digalactosyldiacylglycerol and diacylglycerol-N,N,N-trimethylhomoserine (DGTS), in the model alga Chlamydomonas reinhardtii. However, their respective contribution to PUFA-attached TAG integration has not been clearly deciphered, particularly in starchless Chlamydomonas that hyper-accumulates TAG. In this study, the starchless C. reinhardtii BAFJ5 was mixotrophically cultivated in photobioreactors aerated with air (0.04% CO2), and we monitored the dynamic changes in growth, cellular carbon and nitrogen content, photosynthetic activity, biochemical compositions, and glycerolipid remodeling under high light and nitrogen starvation conditions. The results indicated that multiple PUFAs continually accumulated in total lipids and TAG, and the primary distributors of these PUFAs gradually shifted from membrane lipids to TAG in stress-induced BAFJ5. The stoichiometry analyses showed that the PUFA-attached TAG assembly attributed to turnover of not only the major glycerolipids, but also the phospholipids, phosphatidylethanolamine (PE) and phosphatidylglycerol. Specifically, the augmented C16:3n3 and C18:3n3 in TAG mainly originated from de novo-synthesized galactolipids, while the cumulative C18:3n6 and C18:4n3 in TAG were intimately correlated with conversion of the newly formed DGTS and PE. These findings emphasized significance of PUFA-attached TAG formation dependent on turnover of de novo assembled membrane lipids in starch-deficient Chlamydomonas, beneficial for enhanced production of value-added lipids in microalgae.

Altered Plasma Membrane Lipid Composition in Hypertensive Neutrophils Impacts Epithelial Sodium Channel (ENaC) Endocytosis.

Biological membranes are composed of a lipid bilayer with embedded proteins, including ion channels like the epithelial sodium channel (ENaC), which are critical for sodium homeostasis and implicated in arterial hypertension (HTN). Changes in the lipid composition of the plasma membrane can significantly impact cellular processes related to physiological functions. We hypothesized that the observed overexpression of ENaC in neutrophils from HTN patients might result from alterations in the structuring domains within the plasma membrane, disrupting the endocytic processes responsible for ENaC retrieval. This study assessed the structural lipid composition of neutrophil plasma membranes from HTN patients along with the expression patterns of key elements regulating ENaC at the plasma membrane. Our findings suggest alterations in microdomain structure and SGK1 kinase activity, which could prolong ENaC presence on the plasma membrane. Additionally, we propose that the proteasomal and lysosomal degradation pathways are insufficient to diminish ENaC presence at the plasma membrane in HTN. These results highlight the importance of understanding ENaC retrieval mechanisms and suggest that targeting these mechanisms could provide insights for developing drugs to prevent and treat HTN.

Carlos Gutiérrez-Merino: Synergy of Theory and Experimentation in Biological Membrane Research.

Professor Carlos Gutiérrez-Merino, a prominent scientist working in the complex realm of biological membranes, has made significant theoretical and experimental contributions to the field. Contemporaneous with the development of the fluid-mosaic model of Singer and Nicolson, the Förster resonance energy transfer (FRET) approach has become an invaluable tool for studying molecular interactions in membranes, providing structural insights on a scale of 1-10 nm and remaining important alongside evolving perspectives on membrane structures. In the last few decades, Gutiérrez-Merino's work has covered multiple facets in the field of FRET, with his contributions producing significant advances in quantitative membrane biology. His more recent experimental work expanded the ground concepts of FRET to high-resolution cell imaging. Commencing in the late 1980s, a series of collaborations between Gutiérrez-Merino and the authors involved research visits and joint investigations focused on the nicotinic acetylcholine receptor and its relation to membrane lipids, fostering a lasting friendship.

Amyloid ß production along the neuronal secretory pathway: Dangerous liaisons in the Golgi?

ß-amyloid peptides (Aß) are generated in intracellular compartments of neurons and secreted to form cytotoxic fibrils and plaques. Dysfunctional membrane trafficking contributes to aberrant Aß production and Alzheimer's disease. Endosomes represent one of the major sites for Aß production and recently the Golgi has re-emerged also as a major location for amyloid precursor protein (APP) processing and Aß production. Based on recent findings, here we propose that APP processing in the Golgi is finely tuned by segregating newly-synthesised APP and the ß-secretase BACE1 within the Golgi and into distinct trans-Golgi network transport pathways. We hypothesise that there are multiple mechanisms responsible for segregating APP and BACE1 during transit through the Golgi, and that perturbation in Golgi morphology associated with Alzheimer's disease, and or changes in cholesterol metabolism associated with Alzheimer's disease risk factors, may lead to a loss of partitioning and enhanced Aß production.

Tumor Lipid Signatures Are Descriptive of Acquisition of Therapy Resistance in an Endocrine-Related Breast Cancer Mouse Model.

The lipid metabolism adaptations of estrogen and progesterone receptor-positive breast cancer tumors from a mouse syngeneic model are investigated in relation to differences across the transition from hormone-dependent (HD) to hormone-independent (HI) tumor growth and the acquisition of endocrine therapy (ET) resistance (HIR tumors). Results are articulated with reported polar metabolome results to complete a metabolic picture of the above transitions and suggest markers of tumor progression and aggressiveness. Untargeted nuclear magnetic resonance metabolomics was used to analyze tumor and mammary tissue lipid extracts. Tumor progression (HD-HI-HIR) was accompanied by increased nonesterified cholesterol forms and phospholipids (phosphatidylcholine, phosphatidylethanolamine, sphingomyelins, and plasmalogens) and decreased relative contents of triglycerides and fatty acids. Predominating fatty acids became shorter and more saturated on average. These results were consistent with gradually more activated cholesterol synthesis, ß-oxidation, and phospholipid biosynthesis to sustain tumor growth, as well as an increase in cholesterol (possibly oxysterol) forms. Particular compound levels and ratios were identified as potential endocrine tumor HD-HI-HIR progression markers, supporting new hypotheses to explain acquired ET resistance.

Regulation of PIEZO1 channels by lipids and the structural components of extracellular matrix/cell cytoskeleton.

PIEZO1 is a mechanosensitive channel widely presented in eukaryotic organisms. Although the PIEZO family was discovered in 2010, main questions related to the molecular structure as well as to specific activation mechanisms and regulating pathways remain open. Two hypotheses of PIEZO1 gating were formulated: the first, as a dominant hypothesis, through the plasma membrane (force-from-lipids) and the second, via the participation of the cytoskeleton and the components of the extracellular matrix (ECM) (force-from-filaments). Many researchers provide convincing evidence for both hypotheses. It was demonstrated that PIEZO1 has a propeller-like shape forming a membrane curvature within the lipid bilayer. That suggests the participation of lipids in channel modulation, and many studies demonstrate the critical role of lipids and compounds that modify the lipid bilayer in the regulation of PIEZO1 properties. At the same time, the components of ECM and cortical cytoskeleton can be affected by the membrane curvature and thus have an impact on PIEZO1 properties. In living cells, PIEZO1 properties are reported to be critically dependent on channel microenvironment that is on combinatorial influence of plasma membrane, cytoskeleton and ECM. Thus, it is necessary to understand which factors can affect PIEZO1 and consider them when interpreting the role of PIEZO1 in various physiological processes. This review summarizes the current knowledge about regulation of Piezo1 by lipids and the components of ECM and cytoskeleton.