Cercospora beticola toxins. IX. Relationship between structure of beticolins, inhibition of plasma membrane H+-ATPase and partition in lipid membranes

Cell membranes are very complex biological systems including a large variety of lipids and proteins. Therefore, they are difficult to extract and directly investigate with biophysical methods. For many decades, the characterization of simpler biomimetic lipid membranes, which contain only a few lipid species, provided important physico-chemical information on the most abundant lipid species in cell membranes. These studies described physical and chemical properties that are most likely similar to those of real cell membranes. Indeed, biomimetic lipid membranes can be easily prepared in the lab and are compatible with multiple biophysical techniques. Lipid phase transitions, the bilayer structure, the impact of cholesterol on the structure and dynamics of lipid bilayers, and the selective recognition of target lipids by proteins, peptides, and drugs are all examples of the detailed information about cell membranes obtained by the investigation of biomimetic lipid membranes. This review focuses specifically on the advances that were achieved during the last decade in the field of biomimetic lipid membranes mimicking the mammalian plasma membrane. In particular, we provide a description of the most common types of lipid membrane models used for biophysical characterization, i.e., lipid membranes in solution and on surfaces, as well as recent examples of their applications for the investigation of protein-lipid and drug-lipid interactions. Altogether, promising directions for future developments of biomimetic lipid membranes are the further implementation of natural lipid mixtures for the development of more biologically relevant lipid membranes, as well as the development of sample preparation protocols that enable the incorporation of membrane proteins in the biomimetic lipid membranes.

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Certain, but Not All, Tetraether Lipids from the Thermoacidophilic Archaeon Sulfolobus acidocaldarius Can Form Black Lipid Membranes with Remarkable Stability and Exhibiting Mthk Channel Activity with Unusually High Ca2+ Sensitivity

International Journal of Molecular Sciences ◽

10.3390/ijms222312941 ◽

2021 ◽

Vol 22 (23) ◽

pp. 12941

Author(s):

Alexander Bonanno ◽

Parkson Lee-Gau Chong

Keyword(s):

Plasma Membrane ◽

Potassium Channels ◽

Lipid Membranes ◽

Critical Role ◽

Sulfolobus Acidocaldarius ◽

Domain Formation ◽

Channel Activity ◽

Black Lipid Membranes ◽

Lipid Species ◽

Tetraether Lipids

Bipolar tetraether lipids (BTL) have been long thought to play a critical role in allowing thermoacidophiles to thrive under extreme conditions. In the present study, we demonstrated that not all BTLs from the thermoacidophilic archaeon Sulfolobus acidocaldarius exhibit the same membrane behaviors. We found that free-standing planar membranes (i.e., black lipid membranes, BLM) made of the polar lipid fraction E (PLFE) isolated from S. acidocaldarius formed over a pinhole on a cellulose acetate partition in a dual-chamber Teflon device exhibited remarkable stability showing a virtually constant capacitance (~28 pF) for at least 11 days. PLFE contains exclusively tetraethers. The dominating hydrophobic core of PLFE lipids is glycerol dialky calditol tetraether (GDNT, ~90%), whereas glycerol dialkyl glycerol tetraether (GDGT) is a minor component (~10%). In sharp contrast, BLM made of BTL extracted from microvesicles (Sa-MVs) released from the same cells exhibited a capacitance between 36 and 39 pF lasting for only 8 h before membrane dielectric breakdown. Lipids in Sa-MVs are also exclusively tetraethers; however, the dominating lipid species in Sa-MVs is GDGT (>99%), not GDNT. The remarkable stability of BLMPLFE can be attributed to strong PLFE–PLFE and PLFE–substrate interactions. In addition, we compare voltage-dependent channel activity of calcium-gated potassium channels (MthK) in BLMPLFE to values recorded in BLMSa-MV. MthK is an ion channel isolated from a methanogenic that has been extensively characterized in diester lipid membranes and has been used as a model for calcium-gated potassium channels. We found that MthK can insert into BLMPLFE and exhibit channel activity, but not in BLMSa-MV. Additionally, the opening/closing of the MthK in BLMPLFE is detectable at calcium concentrations as low as 0.1 mM; conversely, in diester lipid membranes at such a low calcium concentration, no MthK channel activity is detectable. The differential effect of membrane stability and MthK channel activity between BLMPLFE and BLMSa-MV may be attributed to their lipid structural differences and thus their abilities to interact with the substrate and membrane protein. Since Sa-MVs that bud off from the plasma membrane are exclusively tetraether lipids but do not contain the main tetraether lipid component GDNT of the plasma membrane, domain segregation must occur in S. acidocaldarius. The implication of this study is that lipid domain formation is existent and functionally essential in all kinds of cells, but domain formation may be even more prevalent and pronounced in hyperthermophiles, as strong domain formation with distinct membrane behaviors is necessary to counteract randomization due to high growth temperatures while BTL in general make archaea cell membranes stable in high temperature and low pH environments whereas different BTL domains play different functional roles.

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Self assembly of HIV-1 Gag protein on lipid membranes generates PI(4,5)P2/Cholesterol nanoclusters

10.1101/081737 ◽

2016 ◽

Author(s):

Naresh Yandrapalli ◽

Quentin Lubart ◽

Hanumant S. Tanwar ◽

Catherine Picart ◽

Johnson Mak ◽

...

Keyword(s):

Plasma Membrane ◽

Self Assembly ◽

Lipid Membranes ◽

Membrane Lipids ◽

Virus Assembly ◽

Specific Interaction ◽

Membrane Lipid ◽

Gag Protein ◽

Gag Polyprotein ◽

Hiv 1

AbstractThe self-assembly of HIV-1 Gag polyprotein at the inner leaflet of the cell host plasma membrane is the key orchestrator of virus assembly. The binding between Gag and the plasma membrane is mediated by specific interaction of the Gag matrix domain and the PI(4,5)P2 lipid (PIP2). It is unknown whether this interaction could lead to local reorganization of the plasma membrane lipids. In this study, using model membranes, we examined the ability of Gag to segregate specific lipids upon self-assembly. We show for the first time that Gag self-assembly is responsible for the formation of PIP2 lipid nanoclusters, enriched in cholesterol but not in sphingomyelin. We also show that Gag mainly partition into liquid-disordered domains of these lipid membranes. Our work strongly suggests that, instead of targeting pre-existing plasma membrane lipid domains, Gag is more prone to generate PIP2/Cholesterol lipid nanodomains at the inner leaflet of the plasma membrane during early events of virus assembly.

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Cercospora beticola toxins. Part XVII. The role of the beticolin/Mg2+ complexes in their biological activity Study of plasma membrane H+-ATPase, vacuolar H+-PPase, alkaline and acid phosphatases

Biochimica et Biophysica Acta (BBA) - Biomembranes ◽

10.1016/s0005-2736(96)00144-7 ◽

1996 ◽

Vol 1285 (1) ◽

pp. 38-46 ◽

Cited By ~ 6

Author(s):

Eric Gomès ◽

Ruth Gordon-Weeks ◽

Françoise Simon-Plas ◽

Alain Pugin ◽

Marie-Louise Milat ◽

...

Keyword(s):

Biological Activity ◽

Plasma Membrane ◽

Cercospora Beticola ◽

Acid Phosphatases ◽

Alkaline And Acid Phosphatases

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Drug Permeation through Biological Barriers

Drug Delivery ◽

10.1093/oso/9780195085891.003.0010 ◽

2001 ◽

Author(s):

W. Mark Saltzman

Keyword(s):

Plasma Membrane ◽

Lipid Composition ◽

Lipid Membranes ◽

Lipid Membrane ◽

Average Molecular Weight ◽

Transport Proteins ◽

Cross Sectional ◽

Tissue Properties ◽

Experimental Systems ◽

Outer Leaflet

In multicellular organisms, thin lipid membranes serve as semipermeable barriers between aqueous compartments. The plasma membrane of the cell separates the cytoplasm from the extracellular space; endothelial cell membranes separate the blood within the vascular space from the rest of the tissue. Properties of the lipid membrane are critically important in regulating the movement of molecules between these aqueous spaces. While certain barrier properties of membranes can be attributed to the lipid components, accessory molecules within the cell membrane—particularly transport proteins and ion channels—control the rate of permeation of many solutes. Transport proteins permit the cell to regulate the composition of its intracellular environment in response to extracellular conditions. The relationship between membrane structure, membrane function, and cell physiology is an area of active, ongoing study. Our interest here is practical: what are the basic mechanisms of drug movement through membranes and how can one best predict the rate of permeation of an agent through a membrane barrier? To answer that question, this section presents rates of permeation measured in some common experimental systems and models of membrane permeation that can be used for prediction. The external surface of the plasma membrane carries a carbohydrate-rich coat called the glycocalyx; charged groups in the glycocalyx, which are provided principally by carbohydrates containing sialic acid, cause the surface to be negatively charged. On average, the plasma membrane of human cells contains, by mass, 50% protein, 45% lipid, and 5% carbohydrate. Given the mass ratio of protein to lipid is ~ 1 : 1, and assuming reasonable values for the average molecular weight and cross-sectional area for each type of molecule (50 × Mw,lipid = Mw,protein; Alipid = 50 Å2 and Aprotein = 1,000 Å2), the area fraction of protein on a typical membrane is ~ 33%. The lipid composition varies in membranes from different cells depending on the type of cell and its function. In addition, the outermost monolayer of lipids, called the outer leaflet, has a different lipid composition from the inner leaflet.

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Cercospora beticola Toxins (X. Inhibition of Plasma Membrane H+-ATPase by Beticolin-1)

PLANT PHYSIOLOGY ◽

10.1104/pp.111.3.773 ◽

1996 ◽

Vol 111 (3) ◽

pp. 773-779 ◽

Cited By ~ 15

Author(s):

F. Simon-Plas ◽

E. Gomes ◽

M. L. Milat ◽

A. Pugin ◽

J. P. Blein

Keyword(s):

Plasma Membrane ◽

Cercospora Beticola

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Green Fluorescent Protein (GFP)-tagged Cysteine-rich Domains from Protein Kinase C as Fluorescent Indicators for Diacylglycerol Signaling in Living Cells

The Journal of Cell Biology ◽

10.1083/jcb.140.3.485 ◽

1998 ◽

Vol 140 (3) ◽

pp. 485-498 ◽

Cited By ~ 248

Author(s):

Elena Oancea ◽

Mary N. Teruel ◽

Andrew F.G. Quest ◽

Tobias Meyer

Keyword(s):

Plasma Membrane ◽

Protein Kinase C ◽

Green Fluorescent Protein ◽

Phorbol Ester ◽

Lipid Membranes ◽

Fluorescent Protein ◽

Living Cells ◽

Membrane Translocation ◽

Kinase C ◽

Green Fluorescent

Cysteine-rich domains (Cys-domains) are ∼50–amino acid–long protein domains that complex two zinc ions and include a consensus sequence with six cysteine and two histidine residues. In vitro studies have shown that Cys-domains from several protein kinase C (PKC) isoforms and a number of other signaling proteins bind lipid membranes in the presence of diacylglycerol or phorbol ester. Here we examine the second messenger functions of diacylglycerol in living cells by monitoring the membrane translocation of the green fluorescent protein (GFP)-tagged first Cys-domain of PKC-γ (Cys1–GFP). Strikingly, stimulation of G-protein or tyrosine kinase–coupled receptors induced a transient translocation of cytosolic Cys1–GFP to the plasma membrane. The plasma membrane translocation was mimicked by addition of the diacylglycerol analogue DiC8 or the phorbol ester, phorbol myristate acetate (PMA). Photobleaching recovery studies showed that PMA nearly immobilized Cys1–GFP in the membrane, whereas DiC8 left Cys1–GFP diffusible within the membrane. Addition of a smaller and more hydrophilic phorbol ester, phorbol dibuterate (PDBu), localized Cys1–GFP preferentially to the plasma and nuclear membranes. This selective membrane localization was lost in the presence of arachidonic acid. GFP-tagged Cys1Cys2-domains and full-length PKC-γ also translocated from the cytosol to the plasma membrane in response to receptor or PMA stimuli, whereas significant plasma membrane translocation of Cys2–GFP was only observed in response to PMA addition. These studies introduce GFP-tagged Cys-domains as fluorescent diacylglycerol indicators and show that in living cells the individual Cys-domains can trigger a diacylglycerol or phorbol ester–mediated translocation of proteins to selective lipid membranes.

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Mechanical properties of plasma membrane vesicles correlate with lipid order and viscosity and depend on cell density

10.1101/669085 ◽

2019 ◽

Author(s):

Jan Steinkühler ◽

Erdinc Sezgin ◽

Iztok Urbančič ◽

Christian Eggeling ◽

Rumiana Dimova

Keyword(s):

Mechanical Properties ◽

Plasma Membrane ◽

Lipid Membranes ◽

Plasma Membranes ◽

Fluorescence Emission ◽

Membrane Vesicles ◽

Seeding Density ◽

Bending Rigidity ◽

Plasma Membrane Vesicles ◽

Lipid Order

AbstractPlasma membranes dynamically respond to external cues and changing environment. Quantitative measurements of these adaptations can elucidate the mechanism that cells exploit to survive, adapt and function. However, cell-based assays are affected by active processes while measurements on synthetic models suffer from compositional limitations. Here, as a model system we employ giant plasma membrane vesicles (GPMVs), which largely preserve the plasma membrane lipidome and proteome. From analysis of fluorescence emission and lifetime of environment-sensitive dyes, and membrane shape fluctuations, we investigate how plasma membrane order, viscosity and bending rigidity are affected by different stimuli such as cell seeding density in three different cell models. Our studies reveal that bending rigidity of plasma membranes vary with lipid order and microviscosity in a highly correlated fashion. Thus, readouts from polarity- and viscosity-sensitive probes represent a promising indicator of membrane mechanical properties. Quantitative analysis of the data allows for comparison to synthetic lipid membranes as plasma membrane mimetics.

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