scholarly journals The N370S (Asn370→Ser) mutation affects the capacity of glucosylceramidase to interact with anionic phospholipid-containing membranes and saposin C

2005 ◽  
Vol 390 (1) ◽  
pp. 95-103 ◽  
Author(s):  
Rosa Salvioli ◽  
Massimo Tatti ◽  
Susanna Scarpa ◽  
Sabrina Maria Moavero ◽  
Fiorella Ciaffoni ◽  
...  
Keyword(s):  
Amino Acid Position ◽  
Anionic Phospholipid ◽  
Anionic Phospholipids ◽  
Saposin C ◽  
Normal Enzyme ◽  
Lysobisphosphatidic Acid ◽  
Lipid Surface ◽  
Prevalent Mutation ◽  
N370s Mutation

The properties of the endolysosomal enzyme GCase (glucosylceramidase), carrying the most prevalent mutation observed in Gaucher patients, namely substitution of an asparagine residue with a serine at amino acid position 370 [N370S (Asn370→Ser) GCase], were investigated in the present study. We previously demonstrated that Sap (saposin) C, the physiological GCase activator, promotes the association of GCase with anionic phospholipid-containing membranes, reconstituting in this way the enzyme activity. In the present study, we show that, in the presence of Sap C and membranes containing high levels of anionic phospholipids, both normal and N370S GCases are able to associate with the lipid surface and to express their activity. Conversely, when the amount of anionic phospholipids in the membrane is reduced (∼20% of total lipids), Sap C is still able to promote binding and activation of the normal enzyme, but not of N370S GCase. The altered interaction of the mutated enzyme with anionic phospholipid-containing membranes and Sap C was further demonstrated in Gaucher fibroblasts by confocal microscopy, which revealed poor co-localization of N370S GCase with Sap C and lysobisphosphatidic acid, the most abundant anionic phospholipid in endolysosomes. Moreover, we found that N370S Gaucher fibroblasts accumulate endolysosomal free cholesterol, a lipid that might further interfere with the interaction of the enzyme with Sap C and lysobisphosphatidic acid-containing membranes. In summary, our results show that the N370S mutation primarily affects the interaction of GCase with its physiological activators, namely Sap C and anionic phospholipid-containing membranes. We thus propose that the poor contact between N370S GCase and its activators may be responsible for the low activity of the mutant enzyme in vivo.

scholarly journals Chemokines act as phosphatidylserine-bound “find-me” signals in apoptotic cell clearance

PLoS Biology ◽  
2021 ◽  
Vol 19 (5) ◽  
pp. e3001259
Author(s):  
Sergio M. Pontejo ◽  
Philip M. Murphy
Keyword(s):  
Chemokine Receptors ◽  
Apoptotic Cell ◽  
Apoptotic Cells ◽  
Anionic Phospholipid ◽  
Anionic Phospholipids ◽  
Apoptotic Cell Clearance ◽  
Cell Clearance ◽  
G Protein Coupled ◽  
Positively Charged

Removal of apoptotic cells is essential for maintenance of tissue homeostasis. Chemotactic cues termed “find-me” signals attract phagocytes toward apoptotic cells, which selectively expose the anionic phospholipid phosphatidylserine (PS) and other “eat-me” signals to distinguish healthy from apoptotic cells for phagocytosis. Blebs released by apoptotic cells can deliver find-me signals; however, the mechanism is poorly understood. Here, we demonstrate that apoptotic blebs generated in vivo from mouse thymus attract phagocytes using endogenous chemokines bound to the bleb surface. We show that chemokine binding to apoptotic cells is mediated by PS and that high affinity binding of PS and other anionic phospholipids is a general property of many but not all chemokines. Chemokines are positively charged proteins that also bind to anionic glycosaminoglycans (GAGs) on cell surfaces for presentation to leukocyte G protein–coupled receptors (GPCRs). We found that apoptotic cells down-regulate GAGs as they up-regulate PS on the cell surface and that PS-bound chemokines, unlike GAG-bound chemokines, are able to directly activate chemokine receptors. Thus, we conclude that PS-bound chemokines may serve as find-me signals on apoptotic vesicles acting at cognate chemokine receptors on leukocytes.

scholarly journals Interaction of saposin D with membranes: effect of anionic phospholipids and sphingolipids

2003 ◽  
Vol 373 (3) ◽  
pp. 785-792 ◽  
Author(s):  
Fiorella CIAFFONI ◽  
Massimo TATTI ◽  
Rosa SALVIOLI ◽  
Anna Maria VACCARO
Keyword(s):  
Critical Value ◽  
Structure And Function ◽  
Slow Process ◽  
Small Particles ◽  
Anionic Phospholipids ◽  
Lysobisphosphatidic Acid ◽  
Dynamic Association ◽  
Lipid Surface ◽  
Definition Of ◽  
And Function

Saposin (Sap) D is an endolysosomal protein that, together with three other similar proteins, Sap A, Sap B and Sap C, is involved in the degradation of sphingolipids and, possibly, in the solubilization and transport of gangliosides. We found that Sap D is able to destabilize and disrupt membranes containing each of the three anionic phospholipids most abundant in the acidic endolysosomal compartment, namely lysobisphosphatidic acid (LBPA), phosphatidylinositol (PI) and phosphatidylserine (PS). The breakdown of the membranes, which occurs when the Sap D concentration on the lipid surface reaches a critical value, is a slow process that gives rise to small particles. The Sap D–particle complexes formed in an acidic milieu can be dissociated by an increase in pH, suggesting a dynamic association of Sap D with membranes. The presence of anionic phospholipids is required also for the Sap D-induced perturbation and solubilization of membranes containing a neutral sphingolipid such as ceramide or a ganglioside such as GM1. At appropriate Sap D concentrations Cer and GM1 are solubilized as constituents of small phospholipid particles. Our findings imply that most functions of Sap D are dependent on its interaction with anionic phospholipids, which mediate the Sap D effect on other components of the membrane such as sphingolipids. On consideration of the properties of Sap D we propose that Sap D might have a role in the definition of the structure and function of membranes, such as the intra-endolysosomal membranes, that are rich in anionic phospholipids.

scholarly journals Size-Tunable Paclitaxel Nanoparticles Stabilized by Anionic Phospholipids for Transdermal Delivery Applications

2020 ◽  
Vol 15 (3) ◽  
pp. 1934578X1990068
Author(s):  
Noriyuki Uchida ◽  
Masayoshi Yanagi ◽  
Hiroki Hamada
Keyword(s):  
Stratum Corneum ◽  
Transdermal Delivery ◽  
Skin Tissue ◽  
Composite Nanoparticles ◽  
Rat Skin ◽  
Cooling Process ◽  
Anionic Phospholipid ◽  
Anionic Phospholipids ◽  
Subsequent Heating

Composite nanoparticles composed of an anionic phospholipid of 1,2-dipalmitoyl-sn-glycero-3-phosphorylglycerol (DPPG) and paclitaxel (PTX) were successfully prepared by mixing them in water followed by a subsequent heating/cooling process. The size of DPPG-PTX nanoparticle could be easily tuned by ultrasonic fragmentation. Upon addition of small-sized fluorescently labeled paclitaxel (FLPTX) nanoparticles with DPPG (DPPG-FLPTX) to rat skin tissue, part of the FLPTX molecules permeated to the stratum corneum.

scholarly journals Extension of the Scope of Anionic Phospholipid-Based Nanoformulation to Kaempferol and Indometacin

2021 ◽  
Vol 16 (3) ◽  
pp. 1934578X2110026
Author(s):  
Noriyuki Uchida ◽  
Masayoshi Yanagi ◽  
Kei Shimoda ◽  
Hiroki Hamada
Keyword(s):  
Phosphatidic Acid ◽  
Anionic Phospholipid ◽  
Anionic Phospholipids ◽  
Dispersion Agent

In this work, resveratrol was dispersed with anionic phospholipids of 1,2-dipalmitoyl-sn-glycero-3-phosphorylglycerol (DPPG), 1,2-dipalmitoyl-sn-glycero-3-phosphatidic acid, and 1,2-distearoyl-sn-glycero-3-phosphoglycerol. Moreover, small-sized nanoparticles of kaempferol and indometacin were successfully prepared by using DPPG as a dispersion agent.

The 536C→T Transition in the Human Tissue Factor Pathway Inhibitor (TFPI) Gene Is Statistically Associated with a Higher Risk for Venous Thrombosis

1999 ◽  
Vol 82 (07) ◽  
pp. 1-5 ◽  
Author(s):  
Michael Schmidt ◽  
Christian Götting ◽  
Britt Schwenz ◽  
Stefan Lange ◽  
Gert Müller-Berghaus ◽  
...  
Keyword(s):  
Venous Thrombosis ◽  
Tissue Factor ◽  
Tissue Factor Pathway Inhibitor ◽  
Blood Donors ◽  
Amino Acid Position ◽  
Immunological Methods ◽  
Venous Thromboembolic ◽  
Coagulation Inhibitors ◽  
Tissue Factor Pathway

SummaryTissue factor pathway inhibitor (TFPI) is an important regulator in the extrinsic blood coagulation pathway. Although the regulatory biochemical role of TFPI is evident, the clinical significance of this proteinase inhibitor remains to be elucidated. The definition of a clinical TFPI deficiency seems to be more complex than that of other coagulation inhibitors because the activity and concentration of circulating TFPI can not be considered a true measure of in vivo levels. Its determination in plasma samples by immunological methods or functional assays has been shown to be inadequate in the detection of a clinical deficiency.Therefore, we screened genomic DNA samples of blood donors and thrombotic patients for alterations in the TFPI gene to assess the influence of a modified TFPI in venous thromboembolic diseases. We detected a single nucleotide substitution in exon 7 (536C→T) leading to a proline to leucine exchange at amino acid position 151 of the protein ([P151L]TFPI) and found the prevalence of heterozygous carriers in German unrelated blood donors to be 0.2% (n = 5120).Four unrelated persons out of 14 probands carrying the genetic variation could be linked to venous thrombosis. For calculation of a potential risk for venous thrombosis for carriers of the mutation we investigated healthy blood donors about thrombotic events. 7 out of 308 blood donors were found to have a history of venous thrombosis, one of them carried the TFPI mutation. Statistical calculation showed a significant relative risk for venous thrombosis for individuals with the trait (odds ratio, 9.3; confidence interval, 1.8-48.6; p <0.01).

scholarly journals Structural basis of control of inward rectifier Kir2 channel gating by bulk anionic phospholipids

2016 ◽  
Vol 148 (3) ◽  
pp. 227-237 ◽  
Author(s):  
Sun-Joo Lee ◽  
Feifei Ren ◽  
Eva-Maria Zangerl-Plessl ◽  
Sarah Heyman ◽  
Anna Stary-Weinzinger ◽  
...  
Keyword(s):  
Transmembrane Domain ◽  
Membrane Lipids ◽  
Inward Rectifier ◽  
Primary Site ◽  
Structural Basis ◽  
Channel Activity ◽  
Anionic Phospholipid ◽  
X Ray ◽  
Anionic Phospholipids ◽  
Kir Channel

Inward rectifier potassium (Kir) channel activity is controlled by plasma membrane lipids. Phosphatidylinositol-4,5-bisphosphate (PIP2) binding to a primary site is required for opening of classic inward rectifier Kir2.1 and Kir2.2 channels, but interaction of bulk anionic phospholipid (PL−) with a distinct second site is required for high PIP2 sensitivity. Here we show that introduction of a lipid-partitioning tryptophan at the second site (K62W) generates high PIP2 sensitivity, even in the absence of PL−. Furthermore, high-resolution x-ray crystal structures of Kir2.2[K62W], with or without added PIP2 (2.8- and 2.0-Å resolution, respectively), reveal tight tethering of the C-terminal domain (CTD) to the transmembrane domain (TMD) in each condition. Our results suggest a refined model for phospholipid gating in which PL− binding at the second site pulls the CTD toward the membrane, inducing the formation of the high-affinity primary PIP2 site and explaining the positive allostery between PL− binding and PIP2 sensitivity.

scholarly journals Molecular determinants of KA1 domain-mediated autoinhibition and phospholipid activation of MARK1 kinase

2017 ◽  
Vol 474 (3) ◽  
pp. 385-398 ◽  
Author(s):  
Ryan P. Emptage ◽  
Mark A. Lemmon ◽  
Kathryn M. Ferguson
Keyword(s):  
Membrane Surface ◽  
Kinase Domain ◽  
Site Directed Mutagenesis ◽  
Anionic Phospholipid ◽  
Anionic Phospholipids ◽  
Disease States ◽  
C Terminus ◽  
Regulatory Module ◽  
Correct Location ◽  
Mechanistic Basis

Protein kinases are frequently regulated by intramolecular autoinhibitory interactions between protein modules that are reversed when these modules bind other ‘activating’ protein or membrane-bound targets. One group of kinases, the MAP/microtubule affinity-regulating kinases (MARKs) contain a poorly understood regulatory module, the KA1 (kinase associated-1) domain, at their C-terminus. KA1 domains from MARK1 and several related kinases from yeast to humans have been shown to bind membranes containing anionic phospholipids, and peptide ligands have also been reported. Deleting or mutating the C-terminal KA1 domain has been reported to activate the kinase in which it is found — also suggesting an intramolecular autoinhibitory role. Here, we show that the KA1 domain of human MARK1 interacts with, and inhibits, the MARK1 kinase domain. Using site-directed mutagenesis, we identify residues in the KA1 domain required for this autoinhibitory activity, and find that residues involved in autoinhibition and in anionic phospholipid binding are the same. We also demonstrate that a ‘mini’ MARK1 becomes activated upon association with vesicles containing anionic phospholipids, but only if the protein is targeted to these vesicles by a second signal. These studies provide a mechanistic basis for understanding how MARK1 and its relatives may require more than one signal at the membrane surface to control their activation at the correct location and time. MARK family kinases have been implicated in a plethora of disease states including Alzheimer's, cancer, and autism, so advancing our understanding of their regulatory mechanisms may ultimately have therapeutic value.

scholarly journals Correlation of Vesicle Binding and Phospholipid Dynamics with Phospholipase C Activity

2009 ◽  
Vol 284 (24) ◽  
pp. 16099-16107 ◽  
Author(s):  
Mingming Pu ◽  
Xiaomin Fang ◽  
Alfred G. Redfield ◽  
Anne Gershenson ◽  
Mary F. Roberts
Keyword(s):  
Enzyme Activity ◽  
Phospholipase C ◽  
Lateral Diffusion ◽  
Lipid Vesicles ◽  
Membrane Lipid ◽  
Correlation Spectroscopy ◽  
Anionic Phospholipid ◽  
Anionic Phospholipids ◽  
Substrate Analogue ◽  
Nmr Methods

The enzymatic activity of the peripheral membrane protein, phosphatidylinositol-specific phospholipase C (PI-PLC), is increased by nonsubstrate phospholipids with the extent of enhancement tuned by the membrane lipid composition. For Bacillus thuringiensis PI-PLC, a small amount of phosphatidylcholine (PC) activates the enzyme toward its substrate PI; above 0.5 mol fraction PC (XPC), enzyme activity decreases substantially. To provide a molecular basis for this PC-dependent behavior, we used fluorescence correlation spectroscopy to explore enzyme binding to multicomponent lipid vesicles composed of PC and anionic phospholipids (that bind to the active site as substrate analogues) and high resolution field cycling 31P NMR methods to estimate internal correlation times (τc) of phospholipid headgroup motions. PI-PLC binds poorly to pure anionic phospholipid vesicles, but 0.1 XPC significantly enhances binding, increases PI-PLC activity, and slows nanosecond rotational/wobbling motions of both phospholipid headgroups, as indicated by increased τc. PI-PLC activity and phospholipid τc are constant between 0.1 and 0.5 XPC. Above this PC content, PI-PLC has little additional effect on the substrate analogue but further slows the PC τc, a motional change that correlates with the onset of reduced enzyme activity. For PC-rich bilayers, these changes, together with the reduced order parameter and enhanced lateral diffusion of the substrate analogue in the presence of PI-PLC, imply that at high XPC, kinetic inhibition of PI-PLC results from intravesicle sequestration of the enzyme from the bulk of the substrate. Both methodologies provide a detailed view of protein-lipid interactions and can be readily adapted for other peripheral membrane proteins.

Ligand-regulated secretion of recombinant annexin V from cultured thyroid epithelial cells

2002 ◽  
Vol 282 (6) ◽  
pp. C1313-C1321 ◽  
Author(s):  
Xiuqiong Wang ◽  
Marcia A. Kaetzel ◽  
Sung E. Yoo ◽  
Paul S. Kim ◽  
John R. Dedman
Keyword(s):  
Mammalian Cells ◽  
Secretory Pathway ◽  
External Surface ◽  
Annexin V ◽  
Therapeutic Agents ◽  
Anionic Phospholipid ◽  
Thyroid Cells ◽  
Tissue Ischemia ◽  
Anionic Phospholipids ◽  
Activated Platelets

The exposure of anionic phospholipids on the external surface of injured endothelial cells and activated platelets is a primary biological signal to initiate blood coagulation. Disease conditions that promote the formation of ectopic thrombi result in tissue ischemia. Annexins, Ca2+-dependent anionic phospholipid binding proteins, are potential therapeutic agents for the inhibition of coagulation. We have designed a transgene that targets secretion of annexin V from cultured thyroid cells under the control of doxycycline. Our results indicate that annexin V in the endoplasmic reticulum (ER)/Golgi lumen does not affect the synthesis, processing, and secretion of thyroglobulin. ER luminal Ca2+was moderately increased and can be released by inositol 1,4,5-trisphosphate. Our study demonstrates that targeting and secretion of annexin V through the secretory pathway of mammalian cells does not adversely affect cellular function. Regulated synthesis and release of annexin V may exert anticoagulatory and anti-inflammatory effects systemically and may prove useful in further developing therapeutic strategies for conditions including antiphospholipid syndrome.

scholarly journals Oyxsterols induce membrane procoagulant activity in monocytic THP-1 cells

1996 ◽  
Vol 314 (3) ◽  
pp. 1027-1033 ◽  
Author(s):  
Karine AUPEIX ◽  
Florence TOTI ◽  
Nathalie SATTA ◽  
Pierre BISCHOFF ◽  
Jean-Marie FREYSSINET
Keyword(s):  
Tissue Factor ◽  
Annexin V ◽  
Antigen Expression ◽  
Resting Cells ◽  
Dependent Manner ◽  
Anionic Phospholipid ◽  
Monocytic Cells ◽  
Anionic Phospholipids ◽  
Phosphatidylserine Exposure ◽  
And Control

Oxidized cholesterol compounds or oxysterols are thought to be potent membrane-destabilizing agents. Anionic phospholipids, chiefly phosphatidylserine, have a procoagulant potential due to their ability to favour the membrane assembly of the characteristic clotting enzyme complexes including the tissue factor-dependent initiating complex. However, in resting cells, phosphatidylserine is sequestered in the inner leaflet of the plasma membrane. When THP-1 monocytic cells were cultured in the presence of 7β-hydroxycholesterol (7β-OH) or 25-hydroxycholesterol (25-OH), prothrombinase, which reflects anionic phospholipid exposure and tissue factor (TF) procoagulant activities, increased in a time- and dose-dependent manner. 7β-OH appeared 1.5- to 2-fold more potent than 25-OH. Interestingly, no effect of cholesterol itself could be detected on procoagulant activities. Nevertheless, no difference in TF activity could be detected between oxysterol-treated and control cells after disruption. TF antigen expression was the same in oxysterol-treated and control cells as shown by flow cytometry. In contrast, the use of labelled annexin V, a protein probe of anionic phospholipids, revealed an elevated number of cells with exposed phosphatidylserine. Because the latter also constitutes a signal for phagocyte recognition of apoptotic cells and fragments, and a proportion of cells displayed altered morphology with condensed chromatin and membrane blebs, analysis of DNA was performed and indicated apoptosis in oxysterol-treated cells. Hence, oxysterol-induced phosphatidylserine exposure and enhanced TF activity may result from apoptosis. These results suggest relationships between oxysterol and the amplification of coagulation reactions by monocytic cells resulting from induced phosphatidylserine exposure.

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