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Cholesterol recognition motif

Sara L Lawrence, Michael A Gorman, Susanne C Feil, Terrence D Mulhern, Michael J Kuiper, Adam J Ratner, Rodney K Tweten, Craig J Morton, Michael W Parker
Cholesterol-dependent cytolysins (CDCs) are a family of pore-forming toxins that punch holes in the outer membrane of eukaryotic cells. Cholesterol serves as the receptor, but a subclass of CDCs first binds to human CD59. Here we describe the crystal structures of vaginolysin and intermedilysin complexed to CD59. These studies, together with small-angle X-ray scattering, reveal that CD59 binds to each at different, though overlapping, sites, consistent with molecular dynamics simulations and binding studies...
September 6, 2016: Structure
Namrata Singh, Debasish Bhattacharyya
Microorganisms express a variety of proteases that degrade many proteins of the host body and subvert host immune response. While elucidating the mechanism/s of an immune stimulatory drug that contains bile lipid, regulation of proteolytic activity was investigated. The drug and bile lipids both stabilize Proteinase K, an aggressive protease of fungal origin against auto-digestion. Among the components of bile lipids, only cholesterol and its derivatives stabilize the enzyme. Biophysical evidences such as scattering of light, intrinsic and extrinsic fluorescence emission spectra, circular dichroism spectra, atomic force microscopy and transmission electron microscopy images indicated that cholesterol and its derivatives interact with Proteinase K...
June 15, 2016: Journal of Cellular Physiology
Masaru Mukai, Kerney Jebrell Glover, Steven L Regen
Two cholesterol recognition/interaction amino-acid consensus peptides, N-acetyl-LWYIKC-amide, and N-acetyl-CLWYIK-amide, have been coupled to exchangeable mimics of Chol (cholesterol) and Phos (1,2-dipalmitoyl-sn-glycerol-3-phospho-(1'rac-glycerol)) via disulfide bond formation. Equilibration between Chol and Phos via thiolate-disulfide interchange reactions has revealed that both peptides favor Chol as a nearest-neighbor in liquid-disordered (ld) bilayers to the same extent. In contrast, no Chol- or Phos-recognition could be detected by these peptides in analogous liquid-ordered (lo) bilayers...
June 21, 2016: Biophysical Journal
Vicente Martínez-Redondo, Paulo R Jannig, Jorge C Correia, Duarte M S Ferreira, Igor Cervenka, Jessica M Lindvall, Indranil Sinha, Manizheh Izadi, Amanda T Pettersson-Klein, Leandro Z Agudelo, Alfredo Gimenez-Cassina, Patricia C Brum, Karin Dahlman-Wright, Jorge L Ruas
Endurance and resistance exercise training induces specific and profound changes in the skeletal muscle transcriptome. Peroxisome proliferator-activated receptor γ coactivator-1 α (PGC-1α) coactivators are not only among the genes differentially induced by distinct training methods, but they also participate in the ensuing signaling cascades that allow skeletal muscle to adapt to each type of exercise. Although endurance training preferentially induces PGC-1α1 expression, resistance exercise activates the expression of PGC-1α2, -α3, and -α4...
July 15, 2016: Journal of Biological Chemistry
Francisco J Barrantes, Jacques Fantini
Pentameric ligand-gated ion channels (pLGICs) and their lipid microenvironments appear to have acquired mutually adaptive traits along evolution: 1) the three-ring architecture of their transmembrane (TM) region; 2) the ability of the outermost TM ring to convey lipid signals to the middle ring, which passes them on to the central pore ring, and 3) consensus motifs for sterol recognition in all pLGICs. Hopanoids are triterpenoid fossil lipids that constitute invaluable biomarkers for tracing evolution at the molecular scale...
July 2016: Progress in Lipid Research
Mireia Pérez-Verdaguer, Jesusa Capera, Ramón Martínez-Mármol, Marta Camps, Núria Comes, Michael M Tamkun, Antonio Felipe
The spatial localization of ion channels at the cell surface is crucial for their functional role. Many channels localize in lipid raft microdomains, which are enriched in cholesterol and sphingolipids. Caveolae, specific lipid rafts which concentrate caveolins, harbor signaling molecules and their targets becoming signaling platforms crucial in cell physiology. However, the molecular mechanisms involved in such spatial localization are under debate. Kv1.3 localizes in lipid rafts and participates in the immunological response...
2016: Scientific Reports
Jacques Fantini, Coralie Di Scala, Luke S Evans, Philip T F Williamson, Francisco J Barrantes
Cholesterol controls the activity of a wide range of membrane receptors through specific interactions and identifying cholesterol recognition motifs is therefore critical for understanding signaling receptor function. The membrane-spanning domains of the paradigm neurotransmitter receptor for acetylcholine (AChR) display a series of cholesterol consensus domains (referred to as "CARC"). Here we use a combination of molecular modeling, lipid monolayer/mutational approaches and NMR spectroscopy to study the binding of cholesterol to a synthetic CARC peptide...
2016: Scientific Reports
Hai-Yun Li, Jing Wang, Fan Meng, Zhe-Kun Jia, Yang Su, Qi-Feng Bai, Ling-Ling Lv, Fu-Rong Ma, Lawrence A Potempa, Yong-Bin Yan, Shang-Rong Ji, Yi Wu
Most proinflammatory actions of C-reactive protein (CRP) are only expressed following dissociation of its native pentameric assembly into monomeric form (mCRP). However, little is known about what underlies the greatly enhanced activities of mCRP. Here we show that a single sequence motif, i.e. cholesterol binding sequence (CBS; a.a. 35-47), is responsible for mediating the interactions of mCRP with diverse ligands. The binding of mCRP to lipoprotein component ApoB, to complement component C1q, to extracellular matrix components fibronectin and collagen, to blood coagulation component fibrinogen, and to membrane lipid component cholesterol, are all found to be markedly inhibited by the synthetic CBS peptide but not by other CRP sequences tested...
April 15, 2016: Journal of Biological Chemistry
Jin-Feng Zhao, Song-Kun Shyue, Tzong-Shyuan Lee
Excess nitric oxide (NO) deregulates cholesterol metabolism in macrophage foam cells, yet the underlying molecular mechanism is incompletely understood. To investigate the mechanism, we found that in macrophages, treatment with NO donors S-nitroso-N-acetyl-D,L-penicillamine (SNAP) or diethylenetriamine/nitric oxide induced LXRα degradation and reduced the expression of the downstream target of LXRα, ATP-binding cassette transporter A1 (ABCA1), and cholesterol efflux. In addition, SNAP induced calcium (Ca(2+)) influx into cells, increased calpain activity and promoted the formation of calpain-LXRα complex...
2016: International Journal of Biological Sciences
Andrew M Ellisdon, Cyril F Reboul, Santosh Panjikar, Kitmun Huynh, Christine A Oellig, Kelly L Winter, Michelle A Dunstone, Wayne C Hodgson, Jamie Seymour, Peter K Dearden, Rodney K Tweten, James C Whisstock, Sheena McGowan
The lethal factor in stonefish venom is stonustoxin (SNTX), a heterodimeric cytolytic protein that induces cardiovascular collapse in humans and native predators. Here, using X-ray crystallography, we make the unexpected finding that SNTX is a pore-forming member of an ancient branch of the Membrane Attack Complex-Perforin/Cholesterol-Dependent Cytolysin (MACPF/CDC) superfamily. SNTX comprises two homologous subunits (α and β), each of which comprises an N-terminal pore-forming MACPF/CDC domain, a central focal adhesion-targeting domain, a thioredoxin domain, and a C-terminal tripartite motif family-like PRY SPla and the RYanodine Receptor immune recognition domain...
December 15, 2015: Proceedings of the National Academy of Sciences of the United States of America
A C Brown, E Koufos, N V Balashova, K Boesze-Battaglia, E T Lally
The leukotoxin (LtxA) produced by Aggregatibacter actinomycetemcomitans kills host immune cells, allowing the bacterium to establish an ecological niche in the upper aerodigestive tract of its human host. The interaction of LtxA with human immune cells is both complex and multifaceted, involving membrane lipids as well as cell-surface proteins. In the initial encounter with the host cell, LtxA associates with lymphocyte function-associated antigen-1, a cell surface adhesion glycoprotein. However, we have also demonstrated that the toxin associates strongly with the plasma membrane lipids, specifically cholesterol...
February 2016: Molecular Oral Microbiology
Rina Ogawa, Kohjiro Nagao, Kentaro Taniuchi, Masaki Tsuchiya, Utako Kato, Yuji Hara, Takehiko Inaba, Toshihide Kobayashi, Yoshihiro Sasaki, Kazunari Akiyoshi, Miho Watanabe-Takahashi, Kiyotaka Nishikawa, Masato Umeda
We employed a multivalent peptide-library screening technique to identify a peptide motif that binds to phosphatidic acid (PA), but not to other phospholipids such as phosphatidylcholine (PC), phosphatidylethanolamine (PE), and phosphatidylserine (PS). A tetravalent peptide with the sequence motif of MARWHRHHH, designated as PAB-TP (phosphatidic acid-binding tetravalent peptide), was shown to bind as low as 1 mol% of PA in the bilayer membrane composed of PC and cholesterol. Kinetic analysis of the interaction between PAB-TP and the membranes containing 10 mol% of PA showed that PAB-TP associated with PA with a low dissociation constant of KD = 38 ± 5 nM...
2015: PloS One
Andrew S Midzak, Nagaraju Akula, Malena B Rone, Vassilios Papadopoulos
Mitochondria play a critical role in the physiological homeostasis of the cell, contributing to numerous cellular processes, including bioenergetics, metabolism and cell life and death. Owing to their keystone role, mitochondria have gained much attention as pharmacological targets. The outer mitochondrial integral membrane translocator protein (TSPO) has attracted a significant degree of pharmacological interest owing to its ability to bind a number of classes of drugs with high affinity and specificity. In addition to its well-characterized drug binding site, TSPO possess an additional high-affinity ligand binding site, originally identified for its ability to bind the lipid cholesterol, which was named the cholesterol recognition/interaction amino acid consensus (CRAC) motif...
September 2015: Pharmacological Research: the Official Journal of the Italian Pharmacological Society
Laura J Sharpe, Geetha Rao, Peter M Jones, Elizabeth Glancey, Shereen M Aleidi, Anthony M George, Andrew J Brown, Ingrid C Gelissen
The ATP-binding cassette (ABC) transporter, ABCG1, is a lipid exporter involved in removal of cholesterol from cells that has been investigated for its role in foam cells formation and atherosclerosis. The mechanism by which ABC lipid transporters bind and recognise their substrates is currently unknown. In this study, we identify a critical region in the final transmembrane domain of ABCG1, which is essential for its export function and stabilisation by cholesterol, a post-translational regulatory mechanism that we have recently identified as dependent on protein ubiquitination...
July 2015: Biochimica et Biophysica Acta
Ozge Sensoy, Harel Weinstein
Helix-8 (Hx8) is a structurally conserved amphipathic helical motif in class-A GPCRs, adjacent to the C-terminal sequence that is responsible for PDZ-domain-recognition. The Hx8 segment in the dopamine D2 receptor (D2R) constitutes the C-terminal segment and we investigate its role in the function of D2R by studying the interaction with the PDZ-containing GIPC1 using homology models based on the X-ray structures of very closely related analogs: the D3R for the D2R model, and the PDZ domain of GIPC2 for GIPC1-PDZ...
April 2015: Biochimica et Biophysica Acta
Dominika Nowis, Agata Malenda, Karolina Furs, Bozenna Oleszczak, Radoslaw Sadowski, Justyna Chlebowska, Malgorzata Firczuk, Janusz M Bujnicki, Adam D Staruch, Radoslaw Zagozdzon, Eliza Glodkowska-Mrowka, Leszek Szablewski, Jakub Golab
OBJECTIVE: Considering the increasing number of clinical observations indicating hyperglycemic effects of statins, this study was designed to measure the influence of statins on the uptake of glucose analogs by human cells derived from liver, adipose tissue, and skeletal muscle. DESIGN: Flow cytometry and scintillation counting were used to measure the uptake of fluorescently labeled or tritiated glucose analogs by differentiated visceral preadipocytes, skeletal muscle cells, skeletal muscle myoblasts, and contact-inhibited human hepatocellular carcinoma cells...
2014: BMJ Open Diabetes Research & Care
Zita Gál, Csilla Hegedüs, Gergely Szakács, András Váradi, Balázs Sarkadi, Csilla Özvegy-Laczka
Human ABCG2 is a plasma membrane glycoprotein causing multidrug resistance in cancer. Membrane cholesterol and bile acids are efficient regulators of ABCG2 function, while the molecular nature of the sterol-sensing sites has not been elucidated. The cholesterol recognition amino acid consensus (CRAC, L/V-(X)(1-5)-Y-(X)(1-5)-R/K) sequence is one of the conserved motifs involved in cholesterol binding in several proteins. We have identified five potential CRAC motifs in the transmembrane domain of the human ABCG2 protein...
February 2015: Biochimica et Biophysica Acta
Cayla M Miller, Angela C Brown, Jeetain Mittal
The cholesterol recognition/interaction amino acid consensus (CRAC) motif is a primary structure pattern used to identify regions that may be responsible for preferential cholesterol binding in many proteins. The leukotoxin LtxA, which is produced by a pathogenic bacterium, contains two CRAC seqences, only one of which is responsible for cholesterol binding, and the binding is required for cytotoxicity. The factors, in addition to the CRAC definition, that may be responsible for cholesterol-binding functionality and atomistic interactions between the CRAC region and cholesterol are as yet unknown...
November 20, 2014: Journal of Physical Chemistry. B
Lucy E Robinson, Mitesh Shridar, Philip Smith, Ruth D Murrell-Lagnado
P2X7 receptors are nonselective cation channels gated by high extracellular ATP, but with sustained activation, receptor sensitization occurs, whereby the intrinsic pore dilates, making the cell permeable to large organic cations, which eventually leads to cell death. P2X7 receptors associate with cholesterol-rich lipid rafts, but it is unclear how this affects the properties of the receptor channel. Here we show that pore-forming properties of human and rodent P2X7 receptors are sensitive to perturbations of cholesterol levels...
November 14, 2014: Journal of Biological Chemistry
Itziar M D Posada, Jacques Fantini, F Xabier Contreras, Francisco Barrantes, Alicia Alonso, Félix M Goñi
Human phospholipid scramblase 1 (SCR) catalyzes phospholipid transmembrane (flip-flop) motion. This protein is assumed to bind the membrane hydrophobic core through a transmembrane domain (TMD) as well as via covalently bound palmitoyl residues. Here, we explore the possible interaction of the SCR TMD with cholesterol by using a variety of experimental and computational biophysical approaches. Our findings indicate that SCR contains an amino acid segment at the C-terminal region that shows a remarkable affinity for cholesterol, although it lacks the CRAC sequence...
September 16, 2014: Biophysical Journal
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