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Query: UNIPROT:P06889 (Mol)
 630,302 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Long-term, serum supplemented cultures of rat adult ventriculocytes were utilized to study the tropic effects of the alpha-agonist phenylephrine and of the carnitine palmitoyltransferase I inhibitor etomoxir. Cell protein and the rate of incorporation of phenylalanine were measured, corrected for cellular DNA content and utilized as an index for hypertrophy and of anabolic activity of the cells, respectively. The mRNA level of ANF was utilized as an index for the pathological phenotypic change (i.e., switch to fetal gene program), and that of the Na-channel--a constantly expressed gene in normal and hypertrophic cardiomyocytes--served as an internal control. Both mRNAs were quantified at various stages in culture by competitive reverse transcriptase PCR. The size of control myocytes steadily increased for over 3 weeks. The cells were completely redifferentiated and reached a maximum of anabolic activity 2 weeks after plating. Secretion and mRNA levels of ANF were increased severalfold after 7-8 days. Addition of 10 microM phenylephrine considerably speeded up cell growth. Maximum anabolic activity and complete redifferentiation were reached already after 1 week. Levels of mRNA and of ANF release increased 30-40 fold. Interestingly, induction of ANF gene transcription lagged behind the redifferentiation of the cells. Ten microM etomoxir inhibited the oxidation of palmitic acid and stimulated that of exogenous glucose by adult cardiomyocytes. In spite of its clear effect on fuel utilization, etomoxir had no direct hypertrophic effect on the myocytes in culture and did not inhibit the stimulatory action of alpha-agonists. Reactivation of the fetal gene program, as visualized by ANF production, was not reversed by etomoxir.
Mol Cell Biochem 1995 Jan 12
PMID:Effect of alpha adrenergic stimulation and carnitine palmitoyl transferase I inhibition on hypertrophying adult rat cardiomyocytes in culture. 775 39

Most members of the family of G protein-coupled receptors have one or more conserved cysteine residues in their carboxy-terminal cytoplasmic tails which are believed to be consensus sites for palmitoylation. Indeed, a growing number of G protein-coupled receptors (rhodopsin, beta 2-, and alpha 2-adrenergic receptors) have now been shown to have palmitic acid covalently attached to this position. In the case of the beta 2-adrenergic receptor, it was also reported that mutation of the palmitoylated cysteine to glycine greatly diminished the ability of this receptor to interact with and activate Gs. Mutation of this conserved cysteine appears to have little or no effect on the ability of other members of this receptor family (rhodopsin, alpha 2-adrenergic and M2 muscarinic) to activate their cognate G proteins, however. The studies presented here were designed to determine whether another Gs-coupled receptor, the LH/CG receptor, is palmitoylated, and whether this modification is important for receptor function. To facilitate biochemical analysis, we examined these issues using cell lines stably transfected with the wild type LH/CG receptor (LHR-wt) or with a mutant receptor in which the two conserved cysteins were mutated to alanines (designated LHR-C621,622A). Our results show that LHR-wt is palmitoylated but that LHR-C621,622A is not. We also show that LHR-C621,622A is capable of binding human CG (hCG) and transducing the cAMP signal. The main difference that we detected between the wild type and mutant receptor is that the latter is trapped intracellularly and does not appear to mature into the 85 kilodalton protein previously identified as the mature cell surface LH/CG receptor.
Mol Endocrinol 1995 Feb
PMID:The lutropin/choriogonadotropin receptor is palmitoylated at intracellular cysteine residues. 777 64

Oligopeptides are an important source of nutrients, but can serve also as signals for intercellular communication. Oligopeptide-binding proteins seem likely to play a role both in oligopeptide transport and in communication processes. One such protein, AmiA, has been identified in Streptococcus pneumoniae. amiA is the first gene of an operon, ami, which encodes a multicomponent oligopeptide transporter belonging to the family of ABC transporters (or traffic ATPases). This transporter was the first system of this type described in Gram-positive bacteria. To investigate the role and the subcellular location of the putative oligopeptide-binding protein in a bacterium devoid of periplasm, AmiA null mutants were first constructed. None was affected for oligopeptide uptake by the Ami system. Since this apparent dispensability of AmiA could result from a functional redundancy, we looked for chromosomal genes encoding homologues of AmiA. Two homologous genes were identified by DNA-DNA hybridization at low stringency with an amiA probe. Both genes (aliA and aliB) were cloned and shown to encode putative lipoproteins highly homologous to AmiA (close to 60% amino acid identity). Examination of all combinations of amiA, aliA and aliB mutations indicated that these proteins have overlapping specificities toward oligopeptides. The triple mutant is as deficient for oligopeptide transport as mutants in the amiCDE or F genes, which demonstrates that an oligopeptide-binding component is absolutely required for transport by the Ami system. Metabolic labelling with [3H]palmitic acid and cell fractionation were used to demonstrate that the three proteins are indeed membrane-bound lipoproteins in S. pneumoniae. This supports our previous hypothesis that substrate-binding lipoproteins are functionally equivalent to the periplasmic substrate-binding component of ABC transporters of Gram-negative bacteria. Finally, the observation that competence for genetic transformation was drastically reduced in a particular AliB mutant suggests that oligopeptide sensing is important for triggering competence.
J Mol Biol 1994 Aug 05
PMID:Three highly homologous membrane-bound lipoproteins participate in oligopeptide transport by the Ami system of the gram-positive Streptococcus pneumoniae. 805 6

Permeabilization of inner mitochondrial membrane by palmitic acid in the presence of Ca2+ (cyclosporin A-sensitive stimulation of respiration, decrease of delta psi and high amplitude swelling) is accompanied by activation of the external pathway of NADH oxidation in liver mitochondria. The "pore"-sealing agents (cyclosporin A, Mg2+ with ADP, and L-carnitine with ATP) are equally effective in preventing the induction of external pathway of NADH oxidation by Ca2+ with palmitate. However, activities of these agents are different in respect to recoupling of permeabilized mitochondria. Participation of cyclosporin A-sensitive "pore" in the fatty acid- and Ca(2+)-dependent induction of external pathway of NADH oxidation and in Ca(2+)-dependent uncoupling is discussed.
Biochem Mol Biol Int 1994 Apr
PMID:Fatty acid-induced Ca(2+)-dependent uncoupling and activation of external pathway of NADH oxidation are coupled to cyclosporin A-sensitive mitochondrial permeability transition. 806 32

The major nonpolar iodolipid formed in horse thyroid cells has recently been identified as 2-iodohexadecanal (2-IHDA). We have investigated in vitro the effect of 2-IHDA on the NADPH-oxidase, NADPH-cytochrome c reductase, and thyroid peroxidase (TPO) activities of a porcine thyroid plasma membrane preparation. 2-IHDA inhibited NADPH-oxidase activity, with half-inhibition at 3-5 microM, but it had no effect on NADPH-cytochrome c reductase. It inhibited the TPO-catalyzed iodination of protein, but not iodide oxidation. Hexadecanal also inhibited NADPH-oxidase. Inhibition by the non-iodinated lipid aldehydes depended on the length of their aliphatic chain: dodecanal and tridecanal gave maximal inhibition. Free iodide, 2-iodohexadecanol and palmitic acid all had no inhibitory effect. Washing treated membranes showed that the inhibition of NADPH-oxidase by hexadecanal was fully reversible, whereas that of 2-IHDA and other iodinated or brominated alkanals was irreversible. Thus the interaction between some residues of the thyroid NADPH-oxidase and the lipid aldehyde groups was favored or stabilized by the iodine atom. Modification of primary amine and thiol groups of NADPH-oxidase inhibited its activity. These groups could also be the target of lipid aldehydes. We suggest that 2-IHDA, because it inhibits TPO and more profoundly the H2O2-generating system in thyroid plasma membrane, modulates iodide metabolism in the thyrocyte and may mediate the Wolff-Chaikoff effect.
Mol Cell Endocrinol 1994 Feb
PMID:Inhibition of thyroid NADPH-oxidase by 2-iodohexadecanal in a cell-free system. 818 56

The effect of TPP+ on the fatty acid or FCCP-induced uncoupling in rat heart mitochondria was studied. It was found that (a) TPP+ increases the stimulation of oxygen consumption by palmitic acid or FCCP in the presence of oligomycin, (b) TPP+ greatly enhances the palmitic acid or FCCP-induced delta psi decrease. Both effects of TPP+ were strongly suppressed by carboxyatractylate in the case of palmitate but were not in the case of FCCP. The role of ATP/ADP-antiporter in the TPP+ and palmitic acid effects is discussed.
Biochem Mol Biol Int 1993 Aug
PMID:Carboxyatractylate inhibits the potentiating effect of lipophylic cation TPP+ on uncoupling activity of fatty acid. 822 Feb 60

Fatty acid-binding protein (FABP) from bovine heart, a 15 kDa cytoplasmic protein has been investigated by multi-dimensional homonuclear and heteronuclear NMR-spectroscopy. Perdeuterated palmitic acid has been used as fatty acid ligand. The tertiary structure has been determined from distance geometry calculations with the variable target functions algorithm (DIANA) utilizing 1027 interproton distance constraints, which were obtained from 1H-homonuclear NOESY spectra. Overlapping NOE crosspeaks were assigned by heteronuclear multidimensional NMR-experiments with a 15N-labelled sample. The tertiary structure resembles a beta-barrel (beta-clam) consisting of ten anti-parallel beta-strands and a short helix-turn-helix motif. The beta-strands are arranged in two nearly orthogonal beta-sheets composed of 5 strands each. The solution structure is compared with the x-ray crystal structure of bovine heart and rat intestinal FABPs.
Mol Cell Biochem
PMID:Solution structure of bovine heart fatty acid-binding protein (H-FABPc). 823 57

Intraalveolar fibrin formation is a hallmark of many acute and chronic lung inflammatory processes. We investigated the influence of fibrin polymerization on biochemical and biophysical properties of a calf lung surfactant extract (CLSE) used for therapy of neonatal distress syndrome. Thrombin-induced coagulation of human fibrinogen (range, 0.04 to 4 mg/ml) in the presence of CLSE (2 mg/ml phospholipids) resulted in progressive loss of surface tension-lowering properties and adsorption facilities of this surfactant preparation; the CLSE-inhibitory capacity of desAABB-fibrin surpassed that of fibrinogen by more than two orders of magnitude. In parallel with the loss of surface activity, association of the predominant surfactant phospholipid dipalmitoylphosphatidylcholine (DPPC) (14C-labeled, admixed to 2 mg/ml CLSE) with polymerizing desAABB-fibrin occurred. A volume of 0.3 mg/ml insoluble fibrin effected a approximately 50% loss, and 0.6 mg/ml a > 90% loss, of DPPC from the aqueous phase. Dioleoylphosphatidylcholine, dipalmitoylphosphatidic acid, stearic acid, palmitic acid, and arachidonic acid, admixed to CLSE as labeled compounds, as well as total CLSE phospholipids were retained in polymerizing desAABB-fibrin with dose-effect curves superimposable to that of DPPC; no fibrin association was noted for 14C-glycerol-3-phosphate. Polymerizing desAA-fibrin, generated by incubation of CLSE-fibrinogen mixtures with arvin, captured DPPC and resulted in loss of surface properties at even lower concentrations, compared with desAABB-fibrin. In contrast, CLSE incubation with preformed desAABB- and desAA-fibrin polymers did not cause substantial phospholipid coupling with the clot material or loss of surface properties. Microtiter plate-immobilized fibrinogen and desAABB- and desAA-fibrinomonomers did not bind CLSE phospholipids enriched with 14C-DPPC.(ABSTRACT TRUNCATED AT 250 WORDS)
Am J Respir Cell Mol Biol 1993 Aug
PMID:Lung surfactant phospholipids associate with polymerizing fibrin: loss of surface activity. 833 88

Photoreactive probes for the hydrophobic pocket of the liver fatty acid-binding protein, 11-(5'-azido-salicylamido)-undecanoic acid (5' ASU) and its acetyl ester (Ac5' ASU), were synthesized and their interaction with the protein was assessed. Fatty acid-binding proteins are closely related proteins which are abundantly expressed in tissues with active lipid metabolism. A simple model that assumes that the protein possesses a single kind of sites fitted the binding of radioiodinated 5' ASU to L-FABP satisfactorily. The apparent dissociation constant, 1.34 x 10(-7) M, evidenced a slightly higher affinity than that reported for C16-C20 fatty acids. Consistent with the binding curve, 5' ASU effectively competed with palmitic acid for the hydrophobic sites and the effect was nearly complete for concentrations of 1 microM; oleic acid, in turn, displaced the radiolabelled probe. Irradiation at 366 nm of 125I-5' ASU bound to L-FABP caused the covalent cross-linking of the reagent. The amount of radioactivity covalently bound reached a maximum after 2 min thus agreeing with the photo-activation kinetics of the unlabelled compound that evidenced a t1/2 of 31.1 sec. The yield with which probes bound to L-FABP became covalently linked to the protein, appraised after SDS-PAGE of irradiated samples, was estimated as 23 and 26 per cent for 5' ASU and Ac5' ASU respectively. In turn, irradiation of L-FABP incubated with 5' ASU or Ac5' ASU resulted in the irreversible loss of about one fourth its ability to bind palmitic acid.(ABSTRACT TRUNCATED AT 250 WORDS)
Mol Cell Biochem 1993 Mar 10
PMID:Photoreactive fatty acid analogues that bind to the rat liver fatty-acid binding protein: 11-(5'-azido-salicylamido)-undecanoic acid derivatives. 845

Abnormal myocardial long-chain fatty acid uptake is suspected of being involved in certain types of heart disease, but the mechanism by which the heart takes up long-chain fatty acids remains unclear. The sulfo-N-succinimidyl derivatives of long-chain fatty acids have been reported to undergo covalent binding to a membrane protein and to irreversibly inhibit the transport of long-chain fatty acids by rat adipocytes (Harmon et al., 1991). It has been suggested that the membrane protein bound by these derivatives is a candidate transporter for long-chain fatty acids in adipocytes. However, myocardial membrane long-chain fatty acid-binding proteins have not yet been fully investigated. Rat hearts were isolated and perfused with a sulfo-N-succinimidyl derivative of tritium-labeled palmitate ([3H]SSP). Then the [3H]SSP-binding protein was characterized by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) autoradiography and histological autoradiography. Myocardial palmitic acid uptake was examined after pretreatment of isolated perfused rat hearts with SSP. The SSP-binding protein was isolated from bovine hearts by successive chromatography, and the amino acid sequences of lysylendopeptidase-digested peptide fragments were determined. SDS-PAGE autoradiography revealed that [3H]SSP bound to an 85-90 kDa protein derived from the myocardial microsomal fraction, and histological autoradiography demonstrated that [3H]SSP radioactivity was localized to the myocardial cell membrane. Pre-incubation with SSP inhibited palmitic acid uptake by isolated perfused rat hearts. A [3H]SSP-binding protein was also found in canine and bovine hearts, and was isolated from the bovine cardiac membrane fraction. Amino acid sequencing revealed that four peptide fragments showed strong sequence homology with rat adipocyte membrane protein, which is implicated in the binding or transport of long-chain fatty acids (Abumrad et al., 1993). We conclude that the SSP-binding protein is localized to the myocardial cell membrane and might be involved in the uptake or transport of long-chain fatty acids.
J Mol Cell Cardiol 1995 Aug
PMID:Isolation of myocardial membrane long-chain fatty acid-binding protein: homology with a rat membrane protein implicated in the binding or transport of long-chain fatty acids. 852 24


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