The substrate specificities of four different lysophospholipases as determined by a novel fluorescence assay.
AuthorsShe HS, Garsetti DE, Steiner MR, Egan RW, Clark MA
JournalBiochem J
PubMed ID8129724
'A novel fluorescence assay for quantifying lysophospholipase activity is described which utilizes a commercially available acrylodated intestinal fatty-acid-binding protein (ADIFAB) and non-radiolabelled substrate. Quantification of enzyme activity is based on the decrease in ADIFAB fluorescence at 432 nm in the presence of nanomolar concentrations of non-esterified (''free'') fatty acids. Lysophospholipase ... More
Assessing the role of calcium-induced calcium release in short-term presynaptic plasticity at excitatory central synapses.
AuthorsCarter AG, Vogt KE, Foster KA, Regehr WG
JournalJ Neurosci
PubMed ID11756484
'Recent evidence suggests that internal calcium stores and calcium-induced calcium release (CICR) provide an important source of calcium that drives short-term presynaptic plasticity at central synapses. Here we tested for the involvement of CICR in short-term presynaptic plasticity at six excitatory synapses in acute rat hippocampal and cerebellar brain slices. ... More
Bovine epidermal fatty acid-binding protein: determination of ligand specificity and cellular localization in retina and testis.
AuthorsKingma PB, Bok D, Ong DE
JournalBiochemistry
PubMed ID9521644
'The fatty acid-binding protein (FABP) family consists of small, cytosolic proteins believed to be involved in the uptake, transport, and solubilization of their hydrophobic ligands. Members of this family have highly conserved sequences and tertiary structures. Using an antibody against testis lipid-binding protein, a member of the FABP family, a ... More
Fatty acid interactions with native and mutant fatty acid binding proteins.
AuthorsRichieri GV, Ogata RT, Kleinfeld AM
JournalMol Cell Biochem
PubMed ID10331661
'The interactions of long chain fatty acids (FA) with wild type (WT) fatty acid binding proteins (FABP) and engineered FABP mutants have been monitored to determine the equilibrium binding constants as well as the rate constants for binding and dissociation. These measurements have been done using the fluorescent probes, ADIFAB ... More
Intracellular pH in adipocytes: effects of free fatty acid diffusion across the plasma membrane, lipolytic agonists, and insulin.
AuthorsCivelek VN, Hamilton JA, Tornheim K, Kelly KL, Corkey BE
JournalProc Natl Acad Sci U S A
PubMed ID8816765
'The main function of white adipose tissue is to store nutrient energy in the form of triglycerides. The mechanism by which free fatty acids (FFA) move into and out of the adipocyte has not been resolved. We show here that changes in intracellular pH (pH1) in adipocytes correlate with the ... More
Role of surface lysine residues of adipocyte fatty acid-binding protein in fatty acid transfer to phospholipid vesicles.
AuthorsLiou HL, Storch J
JournalBiochemistry
PubMed ID11371211
'The tertiary structure of murine adipocyte fatty acid-binding protein (AFABP) is a flattened 10-stranded beta-barrel capped by a helix-turn-helix segment. This helical domain is hypothesized to behave as a "lid" or portal for ligand entry into and exit from the binding cavity. Previously, we demonstrated that anthroyloxy-labeled fatty acid (AOFA) ... More
Monoacylglycerol metabolism in human intestinal Caco-2 cells: evidence for metabolic compartmentation and hydrolysis.
AuthorsHo SY, Delgado L, Storch J
JournalJ Biol Chem
PubMed ID11682480
'Free fatty acids (FFA) and sn-2-monoacylglycerol (MG), the two major hydrolysis products of dietary triacylglycerol (TG), are absorbed from the lumen into polarized enterocytes that line the small intestine. Intensive studies regarding FFA metabolism in the intestine have been published; however, little is known regarding the metabolism of MG. In ... More
Measuring the adsorption of Fatty acids to phospholipid vesicles by multiple fluorescence probes.
AuthorsSimard JR, Kamp F, Hamilton JA,
JournalBiophys J
PubMed ID18296488
'Fatty acids (FA) are important nutrients that the body uses to regulate the storage and use of energy resources. The predominant mechanism by which long-chain fatty acids enter cells is still debated widely as it is unclear whether long-chain fatty acids require protein transporters to catalyze their transmembrane movement. We ... More
Fatty acid binding protein: stimulation of microsomal phosphatidic acid formation.
AuthorsJolly CA, Hubbell T, Behnke WD, Schroeder F
JournalArch Biochem Biophys
PubMed ID9143360
'The effect of fatty acid binding proteins (FABPs) on two key steps of microsomal phosphatidic acid formation was examined. Rat liver microsomes were purified by size-exclusion chromatography to remove endogenous cytosolic fatty acid and fatty acyl-CoA binding proteins while recombinant FABPs were used to avoid cross-contamination with such proteins from ... More
Interactions of alpha-lactalbumin with fatty acids and spin label analogs.
AuthorsCawthern KM, Narayan M, Chaudhuri D, Permyakov EA, Berliner LJ
JournalJ Biol Chem
PubMed ID9388223
'Bovine alpha-lactalbumin (alpha-LA) has been shown by intrinsic protein fluorescence and electron spin resonance methods to interact with the spin-labeled fatty acid analog, 5-doxylstearic acid, as well as stearic acid. An intrinsic fluorescence titration of various alpha-LA forms with 5-doxylstearic acid causes first an increase and then a decrease in ... More
Thermodynamics of fatty acid binding to engineered mutants of the adipocyte and intestinal fatty acid-binding proteins.
AuthorsRichieri GV, Low PJ, Ogata RT, Kleinfeld AM
JournalJ Biol Chem
PubMed ID9516437
'We constructed 18 single amino acid mutants of the adipocyte fatty acid-binding protein (A-FABP) and 17 of the intestinal fatty acid-binding protein (I-FABP), at locations in the fatty acid (FA) binding sites. For each mutant protein, we measured thermodynamic parameters that characterize FA binding. Binding affinities ranged from about 200-fold ... More
Interaction of free fatty acids with phospholipid bilayers.
AuthorsLangner M, Isac T, Hui SW
JournalBiochim Biophys Acta
PubMed ID7794957
'The partition of free fatty acids (FFA) to egg-phosphatidylcholine (egg-PC) and egg-phosphatidylethanolamine (egg-PE) vesicles was studied. Upon the addition of FFA to the suspension of vesicles, the pH of the aqueous phase changed depending on the length and saturation of the FFA hydrocarbon chain, as well as on the vesicle ... More
Continuous measurement of phospholipase A2 activity using the fluorescent probe ADIFAB.
AuthorsRichieri GV, Kleinfeld AM
JournalAnal Biochem
PubMed ID7485980
'A new method is described for the continuous quantitation of phospholipase A2 (PLA2) activity with greatly improved sensitivity compared to existing techniques. The method utilizes a fluorescent probe to detect the release of fatty acid monomers (free fatty acids) into the aqueous phase. The fluorescent probe ADIFAB, which is the ... More
Rapid flip-flop of oleic acid across the plasma membrane of adipocytes.
AuthorsKamp F, Guo W, Souto R, Pilch PF, Corkey BE, Hamilton JA
JournalJ Biol Chem
PubMed ID12499383
'Nonesterified long-chain fatty acids may enter cells by free diffusion or by membrane protein transporters. A requirement for proteins to transport fatty acids across the plasma membrane would imply low partitioning of fatty acids into the membrane lipids, and/or a slower rate of diffusion (flip-flop) through the lipid domains compared ... More
Mechanisms by which intracellular calcium induces susceptibility to secretory phospholipase A2 in human erythrocytes.
AuthorsSmith SK, Farnbach AR, Harris FM, Hawes AC, Jackson LR, Judd AM, Vest RS, Sanchez S, Bell JD
JournalJ Biol Chem
PubMed ID11294854
'Exposure of human erythrocytes to the calcium ionophore ionomycin rendered them susceptible to the action of secretory phospholipase A(2) (sPLA(2)). Analysis of erythrocyte phospholipid metabolism by thin-layer chromatography revealed significant hydrolysis of both phosphatidylcholine and phosphatidylethanolamine during incubation with ionomycin and sPLA(2). Several possible mechanisms for the effect of ionomycin ... More
Binding kinetics of engineered mutants provide insight about the pathway for entering and exiting the intestinal fatty acid binding protein.
AuthorsRichieri GV, Low PJ, Ogata RT, Kleinfeld AM
JournalBiochemistry
PubMed ID10231541
'To better understand the mechanism by which fatty acids bind to and dissociate from the binding cavities of fatty acid binding proteins (FABPs), we constructed 31 single amino acid mutants of the intestinal FABP (I-FABP) and determined the rate constants for binding and dissociation, primarily for long-chain fatty acids (FA). ... More
Definition of the specific roles of lysolecithin and palmitic acid in altering the susceptibility of dipalmitoylphosphatidylcholine bilayers to phospholipase A2.
AuthorsHenshaw JB, Olsen CA, Farnbach AR, Nielson KH, Bell JD
JournalBiochemistry
PubMed ID9692961
'Bilayers composed of phosphatidylcholine initially resist catalysis by phospholipase A2. However, after a latency period, they become susceptible when sufficient reaction products (lysolecithin and fatty acid) accumulate in the membrane. Temperature near the main bilayer phase transition and calcium concentration modulate the effectiveness of the reaction products. The purpose of ... More
Interactions of surfactant protein D with fatty acids.
AuthorsDeSilva NS, Ofek I, Crouch EC
JournalAm J Respir Cell Mol Biol
PubMed ID12816736
'Surfactant Protein D (SP-D) plays important roles in antimicrobial host defense, inflammatory and immune regulation, and pulmonary surfactant homeostasis. The best-characterized endogenous ligand is phosphatidylinositol; however, this lipid interaction at least in part involves the carbohydrate moiety. In this study we observed that SP-D binds specifically to saturated, unsaturated, and ... More
Energetic communication between mitochondria and nucleus directed by catalyzed phosphotransfer.
AuthorsDzeja PP, Bortolon R, Perez-Terzic C, Holmuhamedov EL, Terzic A
JournalProc Natl Acad Sci U S A
PubMed ID12119406
'Exchange of information between the nucleus and cytosol depends on the metabolic state of the cell, yet the energy-supply pathways to the nuclear compartment are unknown. Here, the energetics of nucleocytoplasmic communication was determined by imaging import of a constitutive nuclear protein histone H1. Translocation of H1 through nuclear pores ... More
Equilibrium constants for the binding of fatty acids with fatty acid-binding proteins from adipocyte, intestine, heart, and liver measured with the fluorescent probe ADIFAB.
AuthorsRichieri GV, Ogata RT, Kleinfeld AM
JournalJ Biol Chem
PubMed ID7929039
'Affinities of long chain fatty acids (FA) for fatty acid-binding proteins (FABPs) have been measured by monitoring the concentrations of the unbound or free fatty acids (FFA) in equilibrium with the FABPs using the fluorescent probe ADIFAB. This probe allows the measurement of the concentration of FFA in equilibrium with ... More
Inactive fatty acids are unable to flip-flop across the lipid bilayer.
AuthorsJezek P, Modrianský M, Garlid KD
JournalFEBS Lett
PubMed ID9187359
'Free fatty acids (FA) were found which did not acidify liposome interior. This is interpreted as their inability to rapidly flip-flop across the lipid bilayer. However, they were able to partition in lipids as detected directly using HPLC or from the shift of their equilibrium binding to acrylodated intestinal binding ... More
Actin-ATP hydrolysis is a major energy drain for neurons.
AuthorsBernstein BW, Bamburg JR
JournalJ Neurosci
PubMed ID12514193
In cultured chick ciliary neurons, when ATP synthesis is inhibited, ATP depletion is reduced approximately 50% by slowing actin filament turnover with jasplakinolide or latrunculin A. Jasplakinolide inhibits actin disassembly, and latrunculin A prevents actin assembly by sequestering actin monomers. Cytochalasin D, which allows assembly-disassembly, but only at pointed ends, ... More
The measurement of free fatty acid concentration with the fluorescent probe ADIFAB: a practical guide for the use of the ADIFAB probe.
AuthorsRichieri GV, Ogata RT, Kleinfeld AM
JournalMol Cell Biochem
PubMed ID10331662
The aqueous phase monomers of fatty acids (FFA) appear in many steps of fat metabolism. Understanding metabolism requires that accurate measurements of FFA levels be determined in enzyme-mediated as well as in membrane and protein binding reactions. Measuring long chain FFA levels with sufficient sensitivity and temporal resolution is now ... More
Free fatty acid transport across adipocytes is mediated by an unknown membrane protein pump.
AuthorsKampf JP, Parmley D, Kleinfeld AM,
JournalAm J Physiol Endocrinol Metab
PubMed ID17711989
The role of cell membranes in regulating the flux of long chain free fatty acids (FFA) into and out of adipocytes is intensely debated. Four different membrane proteins including, FABPpm, CD36/FAT, caveolin-1, and FATP have been identified as facilitating FFA transport. Moreover, CD36 and caveolin-1 are also reported to mediate ... More
Relationship between membrane physical properties and secretory phospholipase A2 hydrolysis kinetics in S49 cells during ionophore-induced apoptosis.
AuthorsBailey RW, Olson ED, Vu MP, Brueseke TJ, Robertson L, Christensen RE, Parker KH, Judd AM, Bell JD,
JournalBiophys J
PubMed ID17545239
During apoptosis, changes occur in lymphocyte membranes that render them susceptible to hydrolysis by secretory phospholipase A(2) (sPLA(2)). To study the relevant mechanisms, a simplified model of apoptosis using a calcium ionophore was applied. Kinetic and flow cytometry experiments provided key observations regarding ionophore treatment: the initial rate of hydrolysis ... More
Alpha1E-containing Ca2+ channels are involved in synaptic plasticity.
AuthorsBreustedt J, Vogt KE, Miller RJ, Nicoll RA, Schmitz D
JournalProc Natl Acad Sci U S A
PubMed ID14519849
Long-term potentiation (LTP) is the most prominent model for the molecular and cellular mechanisms of learning and memory. Two main forms of LTP have been distinguished. The N-methyl-D-aspartate-receptor-dependent forms of LTP have been studied most extensively, whereas much less is known about N-methyl-D-aspartate-receptor-independent forms of LTP. This latter type of ... More
High resolution crystal structures of human Rab5a and five mutants with substitutions in the catalytically important phosphate-binding loop.
AuthorsZhu G, Liu J, Terzyan S, Zhai P, Li G, Zhang XC
JournalJ Biol Chem
PubMed ID12433916
GTPase domain crystal structures of Rab5a wild type and five variants with mutations in the phosphate-binding loop are reported here at resolutions up to 1.5 A. Of particular interest, the A30P mutant was crystallized in complexes with GDP, GDP+AlF(3), and authentic GTP, respectively. The other variant crystals were obtained in ... More
Fungi and animals may share a common ancestor to nuclear receptors.
AuthorsPhelps C, Gburcik V, Suslova E, Dudek P, Forafonov F, Bot N, MacLean M, Fagan RJ, Picard D
JournalProc Natl Acad Sci U S A
PubMed ID16636289
Nuclear receptors (NRs) are a large family of transcription factors. One hallmark of this family is the ligand-binding domain (LBD), for its primary sequence, structure, and regulatory function. To date, NRs have been found exclusively in animals and sponges, which has led to the generally accepted notion that they arose ... More
Unbound free fatty acid levels in human serum.
AuthorsRichieri GV, Kleinfeld AM
JournalJ Lipid Res
PubMed ID7751810
Total serum free fatty acids (FFAt) levels provide an important measure of the physiologic state. Most of the FFA in serum is bound to albumin; a small portion, however, is unbound. This study presents the first measurements of serum unbound free fatty acid (FFAu) concentrations. These measurements were made possible ... More
Photoacoustic analysis of proteins: volumetric signals and fluorescence quantum yields.
AuthorsKurian E, Prendergast FG, Small JR
JournalBiophys J
PubMed ID9199809
A series of proteins has been examined using time-resolved, pulsed-laser volumetric photoacoustic spectroscopy. Photoacoustic waveforms were collected to measure heat release for calculation of fluorescence quantum yields, and to explore the possibility of photoinduced nonthermal volume changes occurring in these protein samples. The proteins studied were the green fluorescent protein ... More
Tyrosine phosphorylation of a 100-kDa protein is correlated with cytotoxic T-lymphocyte function. Evidence from cis unsaturated fatty acid and phenylarsineoxide inhibition.
AuthorsAnel A, Kleinfeld AM
JournalJ Biol Chem
PubMed ID8394347
Cis unsaturated but not saturated fatty acids (FA) have been shown to specifically inhibit certain early responses in cytotoxic T-lymphocytes (CTL) including the rise in intracellular calcium, degranulation, and lethal hit delivery. They do not, however, affect other early events such as the turnover of phosphatidylinositol, T-cell receptor recognition, and ... More
Zero-order interfacial enzymatic degradation of phospholipid tubules.
AuthorsCarlson PA, Gelb MH, Yager P
JournalBiophys J
PubMed ID9199787
The first study of enzymatic hydrolysis of phospholipid tubules is reported. Phosphatidylcholines with acyl chains containing diacetylene groups are known to form tubular microstructures in which the lipids are tightly packed and crystalline. These tubules can be used to probe the role of microstructural form in the mechanics of interfacial ... More
Increases in serum unbound free fatty acid levels following coronary angioplasty.
AuthorsKleinfeld AM, Prothro D, Brown DL, Davis RC, Richieri GV, DeMaria A
JournalAm J Cardiol
PubMed ID8970405
Serum unbound free fatty acid levels (FFAu) were measured in patients undergoing percutaneous transluminal coronary angioplasty (PTCA) using the fluorescent probe acrylodan intestinal fatty acid binding protein (ADIFAB). These are the first measurements of FFAu, under nonphysiologic conditions. In these studies, FFAu, levels were determined in 22 patients 5 minutes ... More
A fluorescently labeled intestinal fatty acid binding protein. Interactions with fatty acids and its use in monitoring free fatty acids.
AuthorsRichieri GV, Ogata RT, Kleinfeld AM
JournalJ Biol Chem
PubMed ID1429693
The fatty acid-binding protein from rat intestine (I-FABP) has been covalently modified with the fluorescent compound Acrylodan. Acrylodan was found to label Lys27, one of the few amino acid residues found by x-ray diffraction studies to change orientation upon fatty acid (FA) binding to I-FABP. Binding of FA to this ... More
Interactions of long-chain fatty acids and albumin: determination of free fatty acid levels using the fluorescent probe ADIFAB.
AuthorsRichieri GV, Anel A, Kleinfeld AM
JournalBiochemistry
PubMed ID8338853
Equilibrium binding of long-chain fatty acids (FA) with albumin from human serum (HSA), bovine serum (BSA), and murine serum (MSA) has been studied by measuring the equilibrium levels of free fatty acids (FFA). FFA levels were measured directly, using a new fluorescent probe composed of acrylodan-derivatized intestinal fatty acid binding ... More
Mechanisms by which elevated intracellular calcium induces S49 cell membranes to become susceptible to the action of secretory phospholipase A2.
AuthorsWilson HA, Waldrip JB, Nielson KH, Judd AM, Han SK, Cho W, Sims PJ, Bell JD
JournalJ Biol Chem
PubMed ID10206954
Exposure of S49 lymphoma cells to exogenous group IIA or V secretory phospholipase A2 (sPLA2) caused an initial release of fatty acid followed by resistance to further hydrolysis by the enzyme. This refractoriness was overcome by exposing cells to palmitoyl lysolecithin. This effect was specific in terms of lysophospholipid structure. ... More
Kinetics of fatty acid interactions with fatty acid binding proteins from adipocyte, heart, and intestine.
AuthorsRichieri GV, Ogata RT, Kleinfeld AM
JournalJ Biol Chem
PubMed ID8626681
Rate constants for the interaction of fatty acids (FA) with fatty acid binding proteins (FABP) from adipocyte (A-FABP), heart (H-FABP), and intestine (I-FABP) were determined by using stopped-flow fluorometry and ADIFAB, the fluorescent probe of free fatty acids (FFA), or a new FFA probe, ADIFAB2, constructed by derivatizing with acrylodan ... More
Survey of binding properties of fatty acid-binding proteins. Chromatographic methods.
AuthorsMassolini G, Calleri E
JournalJ Chromatogr B Analyt Technol Biomed Life Sci
PubMed ID14630154
Fatty acid-binding proteins (FABPs) are members of a super family of lipid-binding proteins, and occur intracellularly in vertebrates and invertebrates. This review briefly addresses the structural and molecular properties of the fatty acid binding proteins, together with their potential physiological role. Special attention is paid to the methods used to ... More
Transport of long-chain native fatty acids across human erythrocyte ghost membranes.
AuthorsKleinfeld AM, Storms S, Watts M
JournalBiochemistry
PubMed ID9609694
Evidence from a number of laboratories suggests that membrane proteins may meditate the transport of physiologic fatty acids (FA) across cell membranes. However, actual transport of unbound free fatty acids (unbound FFA) from the aqueous phase on one side of a cell membrane to the aqueous phase on the other ... More
Evidence for a regulatory role of cholesterol superlattices in the hydrolytic activity of secretory phospholipase A2 in lipid membranes.
AuthorsLiu F, Chong PL
JournalBiochemistry
PubMed ID10194297
We have conducted a detailed study of the effect of membrane cholesterol content on the initial hydrolytic activity of Crotalus durissus terrificus venom phospholipase A2 (sPLA2) in large unilamellar vesicles of cholesterol/dimyristoyl-L-alpha-phosphatidylcholine (DMPC) and cholesterol/1-palmitoyl-2-oleoyl-L-alpha-phosphatidylcholine (POPC) at 37 degrees C. The activity was monitored by using the acrylodan-labeled intestinal fatty ... More
Thermodynamic and kinetic properties of fatty acid interactions with rat liver fatty acid-binding protein.
AuthorsRichieri GV, Ogata RT, Kleinfeld AM
JournalJ Biol Chem
PubMed ID8940102
Fatty acid-binding protein from rat liver (L-FABP) binds 2 fatty acids (FA) per protein, in contrast to FABPs from adipocyte, heart, and intestine, for which binding and structural studies are consistent with a single FA binding site. To understand better the unique characteristics of L-FABP, we have carried out equilibrium ... More
Thermodynamics of fatty acid binding to fatty acid-binding proteins and fatty acid partition between water and membranes measured using the fluorescent probe ADIFAB.
AuthorsRichieri GV, Ogata RT, Kleinfeld AM
JournalJ Biol Chem
PubMed ID7797491
Using the fluorescent probe ADIFAB (acrylodan-derivatized intestinal fatty acid-binding protein) to determine the equilibrium concentration of the free (unbound) fatty acid (FFA), dissociation constants were measured between 10 and 50 degrees C for the interaction of five different long chain fatty acids (FA) with fatty acid-binding proteins (FABP) from adipocyte, ... More
Transport of long-chain native fatty acids across lipid bilayer membranes indicates that transbilayer flip-flop is rate limiting.
AuthorsKleinfeld AM, Chu P, Romero C
JournalBiochemistry
PubMed ID9369487
Evidence from a number of laboratories suggests that membrane proteins may meditate the transport of physiologic fatty acids (FA) across cell membranes. However, studies using lipid membranes indicate that FA are capable of spontaneous flip-flip, raising the possibility that rapid transport through the lipid phase obviates the need for a ... More
Fatty acid binding proteins from different tissues show distinct patterns of fatty acid interactions.
AuthorsRichieri GV, Ogata RT, Zimmerman AW, Veerkamp JH, Kleinfeld AM
JournalBiochemistry
PubMed ID10852718
Fatty acid binding proteins (FABP) form a family of proteins displaying tissue-specific expression. These proteins are involved in fatty acid (FA) transport and metabolism by mechanisms that also appear to be tissue-specific. Cellular retinoid binding proteins are related proteins with unknown roles in FA transport and metabolism. To better understand ... More
Different mechanisms of free fatty acid flip-flop and dissociation revealed by temperature and molecular species dependence of transport across lipid vesicles.
AuthorsKampf JP, Cupp D, Kleinfeld AM
JournalJ Biol Chem
PubMed ID16737957
The mechanism of free fatty acid (FFA) transport across membranes is a subject of intense investigation. We have demonstrated recently that flip-flop is the rate-limiting step for transport of oleic acid across phospholipid vesicles (Cupp, D., Kampf, J. P., and Kleinfeld, A. M. (2004) Biochemistry 43, 4473-4481). To better understand ... More
Membrane partition of fatty acids and inhibition of T cell function.
AuthorsAnel A, Richieri GV, Kleinfeld AM
JournalBiochemistry
PubMed ID8422363
Short-term exposure to elevated levels of free fatty acids (FFA) perturbs a variety of cellular functions. It is frequently observed that cis-unsaturated fatty acids (FA) mediate these perturbations while trans-unsaturated or saturated FA are relatively inert. This dichotomy has generally been ascribed to the differential effects of these FA on ... More
GABA uptake into astrocytes is not associated with significant metabolic cost: implications for brain imaging of inhibitory transmission.
AuthorsChatton JY, Pellerin L, Magistretti PJ
JournalProc Natl Acad Sci U S A
PubMed ID14530410
Synaptically released glutamate has been identified as a signal coupling excitatory neuronal activity to increased glucose utilization. The proposed mechanism of this coupling involves glutamate uptake into astrocytes resulting in increased intracellular Na+ (Nai+) and activation of the Na+/K+-ATPase. Increased metabolic demand linked to disruption of Nai+ homeostasis activates glucose ... More
The cannabinoid CB1 receptor mediates retrograde signals for depolarization-induced suppression of inhibition in cerebellar Purkinje cells.
AuthorsYoshida T, Hashimoto K, Zimmer A, Maejima T, Araishi K, Kano M
JournalJ Neurosci
PubMed ID11880498
Action potential firing or depolarization of the postsynaptic neuron can induce a transient suppression of inhibitory synaptic inputs to the depolarized neuron in the cerebellum and hippocampus. This phenomenon, termed depolarization-induced suppression of inhibition (DSI), is initiated postsynaptically by an elevation of intracellular Ca2+ concentration ([Ca2+]i) and is expressed presynaptically ... More
A tyrosine phosphorylation requirement for cytotoxic T lymphocyte degranulation.
AuthorsAnel A, Richieri GV, Kleinfeld AM
JournalJ Biol Chem
PubMed ID7511589
Phorbol myristate acetate (PMA) plus ionomycin induces the tyrosine phosphorylation of several cytotoxic T lymphocyte (CTL) substrates, including one with an apparent molecular weight of 100,000 (pp100) in cloned murine CTL. cis-Unsaturated fatty acids and low concentrations of phenylarsine oxide specifically inhibit the tyrosine phosphorylation of pp100. Genistein also inhibits ... More
Protein-membrane interaction and fatty acid transfer from intestinal fatty acid-binding protein to membranes. Support for a multistep process.
AuthorsFalomir-Lockhart LJ, Laborde L, Kahn PC, Storch J, Córsico B
JournalJ Biol Chem
PubMed ID16551626
Fatty acid transfer from intestinal fatty acid-binding protein (IFABP) to phospholipid membranes occurs during protein-membrane collisions. Electrostatic interactions involving the alpha-helical "portal" region of the protein have been shown to be of great importance. In the present study, the role of specific lysine residues in the alpha-helical region of IFABP ... More
Role of the helical domain in fatty acid transfer from adipocyte and heart fatty acid-binding proteins to membranes: analysis of chimeric proteins.
AuthorsLiou HL, Kahn PC, Storch J
JournalJ Biol Chem
PubMed ID11675390
The adipocyte and heart fatty acid-binding proteins (A- and HFABP) are members of a lipid-binding protein family with a beta-barrel body capped by a small helix-turn-helix motif. Both proteins are hypothesized to transport fatty acid (FA) to phospholipid membranes through a collisional process. Previously, we suggested that the helical domain ... More
Role of caveolin-1 and cholesterol in transmembrane fatty acid movement.
AuthorsMeshulam T, Simard JR, Wharton J, Hamilton JA, Pilch PF
JournalBiochemistry
PubMed ID16503643
We have created by transfection a series of HEK 293 cell lines that express varying amounts of caveolin-1 to test the possible effect of this protein on the transport and metabolism of long chain fatty acids (FA) in cells with this gain of function. We used an extracellular fluorescent probe ... More
The alpha-helical domain of liver fatty acid binding protein is responsible for the diffusion-mediated transfer of fatty acids to phospholipid membranes.
AuthorsCórsico B, Liou HL, Storch J
JournalBiochemistry
PubMed ID15035630
Intestinal fatty acid binding protein (IFABP) and liver FABP (LFABP), homologous proteins expressed at high levels in intestinal absorptive cells, employ markedly different mechanisms for the transfer of fatty acids (FAs) to acceptor membranes. Transfer from IFABP occurs during protein-membrane collisional interactions, while for LFABP, transfer occurs by diffusion through ... More