Myristic acid was identified as a metabolite with the highest diagnostic sensitivity and specificity in the metabolome of patients with bacteraemia. Subsequently, its significant decrease was observed in patients in septic shock not responding to treatment. In our study we have captured myristic acid serum level kinetics in 96 hours following accidental intravenous self-administration of eubiotic Hylak forte causing infection-like systemic inflammatory response syndrome (SIRS). To our knowledge, this is the first time the kinetics of myristic acid levels is presented in a septic patient. Myristic acid was evaluated in comparison with other inflammatory biomarkers and with its level in a control group of healthy subjects. Myristic acid levels during septic response were significantly elevated in comparison with the control group. The peak level was recorded almost immediately after the insult with a gradual decrease within 96 hours. Myristic acid appears to be a promising biomarker in sepsis diagnostics, further research by our group into this topic is ongoing.

• Klíčová slova
• Biomarkers, Kinetics, Myristic acid, Sepsis,
• MeSH
• biologické markery analýza   metabolismus   MeSH
• kinetika MeSH
• kyselina myristová metabolismus   MeSH
• lidé MeSH
• sepse metabolismus   MeSH
• septický šok metabolismus   MeSH
• syndrom MeSH
• zánět metabolismus   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• biologické markery MeSH
• kyselina myristová MeSH

The present experiments were performed to evaluate if increased heart tissue concentration of fatty acids, specifically myristic, palmitic and palmitoleic acids that are believed to promote physiological heart growth, can attenuate the progression of unloading-induced cardiac atrophy in rats with healthy and failing hearts. Heterotopic abdominal heart transplantation (HT(x)) was used as a model for heart unloading. Cardiac atrophy was assessed from the ratio of the native- to-transplanted heart weight (HW). The degree of cardiac atrophy after HT(x) was determined on days 7, 14, 21 and 28 after HT(x) in recipients of either healthy or failing hearts. HT(x) of healthy hearts resulted in 23+/-3, 46+/-3, 48+/-4 and 46+/-4 % HW loss at the four time-points. HT(x) of the failing heart resulted in even greater HW losses, of 46+/-4, 58+/-3, 66+/-2 and 68+/-4 %, respectively (P<0.05). Activation of "fetal gene cardiac program" (e.g. beta myosin heavy chain gene expression) and "genes reflecting cardiac remodeling" (e.g. atrial natriuretic peptide gene expression) after HT(x) was greater in failing than in healthy hearts (P<0.05 each time). Exposure to isocaloric high sugar diet caused significant increases in fatty acid concentrations in healthy and in failing hearts. However, these increases were not associated with any change in the course of cardiac atrophy, similarly in healthy and post-HT(x) failing hearts. We conclude that increasing heart tissue concentrations of the fatty acids allegedly involved in heart growth does not attenuate the unloading-induced cardiac atrophy.

• MeSH
• heterotopická transplantace metody   MeSH
• kardiomyocyty metabolismus   MeSH
• krysa rodu Rattus MeSH
• kyselina myristová metabolismus   MeSH
• kyselina palmitová metabolismus   MeSH
• kyseliny mastné mononenasycené metabolismus   MeSH
• myokard metabolismus   patologie   MeSH
• potkani inbrední LEW MeSH
• srdeční selhání metabolismus   chirurgie   MeSH
• transplantace srdce metody   MeSH
• zvířata MeSH
• Check Tag
• krysa rodu Rattus MeSH
• mužské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• kyselina myristová MeSH
• kyselina palmitová MeSH
• kyseliny mastné mononenasycené MeSH
• palmitoleic acid MeSH Prohlížeč

The plant-specific DREPP protein family comprises proteins that were shown to regulate the actin and microtubular cytoskeleton in a calcium-dependent manner. Our phylogenetic analysis showed that DREPPs first appeared in ferns and that DREPPs have a rapid and plastic evolutionary history in plants. Arabidopsis DREPP paralogues called AtMDP25/PCaP1 and AtMAP18/PCaP2 are N-myristoylated, which has been reported as a key factor in plasma membrane localization. Here we show that N-myristoylation is neither conserved nor ancestral for the DREPP family. Instead, by using confocal microscopy and a new method for quantitative evaluation of protein membrane localization, we show that DREPPs rely on two mechanisms ensuring their plasma membrane localization. These include N-myristoylation and electrostatic interaction of a polybasic amino acid cluster. We propose that various plasma membrane association mechanisms resulting from the evolutionary plasticity of DREPPs are important for refining plasma membrane interaction of these signalling proteins under various conditions and in various cells.

• Klíčová slova
• AtMDP25/PCaP1, DREPP, N-myristoylation, Nicotiana tabacum, Polybasic cluster,
• MeSH
• biologická evoluce MeSH
• buněčná membrána chemie   MeSH
• fylogeneze MeSH
• kyselina myristová metabolismus   MeSH
• membránové proteiny chemie   MeSH
• rostlinné proteiny chemie   MeSH
• statická elektřina MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• kyselina myristová MeSH
• membránové proteiny MeSH
• rostlinné proteiny MeSH

The matrix protein (MA) of the Mason-Pfizer monkey virus (M-PMV) plays a key role in the transport and budding of immature retroviral particles from the host cell. Natural N-terminal myristoylation of MA is essential for the targeting of the particles to the plasma membrane and participates in the interaction of MA with membranes phospholipids. The mutation Y28F/Y67F in MA reduces budding and thus causes the accumulation of viral particles under the cytoplasmic membrane. To investigate the impact of Y28F/Y67F mutation on the structure of MA, we prepared this protein in amount and quality suitable for NMR spectroscopy. We report backbone, side-chain and myristoyl residue assignments of the Y28F/Y67F mutant of the M-PMV matrix protein, which will be used to study the interaction with membrane phospholipids and to determine the structure of the mutant matrix protein.

• Klíčová slova
• Isotopic labeling, M-PMV, Matrix protein, Myristoylation, Resonance assignment, Reverse labeling,
• MeSH
• kyselina myristová metabolismus   MeSH
• Masonův-Pfizerův opičí virus metabolismus   MeSH
• mutantní proteiny chemie   MeSH
• nukleární magnetická rezonance biomolekulární * MeSH
• proteiny virové matrix chemie   MeSH
• protonová magnetická rezonanční spektroskopie MeSH
• sekundární struktura proteinů MeSH
• spektrometrie hmotnostní - ionizace laserem za účasti matrice MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• kyselina myristová MeSH
• mutantní proteiny MeSH
• proteiny virové matrix MeSH

Nuclear magnetic resonance (NMR) is a powerful technique for solving protein structures or studying their interactions. However, it requires molecules labeled with NMR sensitive isotopes like carbon (13)C and nitrogen (15)N. The recombinant expression of labeled proteins is simple to perform but requires quite expensive chemicals. When there is a need for special labeled chemicals, like uniformly (13)C-labeled myristic acid, the price significantly rises. Here we describe a cost-effective method for the recombinant expression of uniformly labeled myristoylated proteins in Escherichia coli demonstrated on the production of Mason-Pfizer monkey virus matrix protein. We used the ability of E. coli to naturally synthetize myristic acid. When grown in isotopically labeled medium the myristic acid will be labelled as well. Bacteria were co-transfected with plasmid carrying gene for yeast N-myristoyltransferase which ensures myristoylation of expressed protein. This process provided 1.8mg of the myristoylated, doubly labeled ((13)C/(15)N)M-PMV matrix protein from 1L of (15)N/(13)C labeled M9 medium. The price represents approximately 50% cost reduction of conventional method using commercially available [U-(13)C]myristic acid.

• Klíčová slova
• Isotopic labeling, M-PMV, Matrix protein, N-terminal myristoylation, NMR,
• MeSH
• acylace MeSH
• acyltransferasy genetika   metabolismus   MeSH
• Escherichia coli genetika   metabolismus   MeSH
• izotopové značení ekonomika   metody   MeSH
• izotopy dusíku MeSH
• izotopy uhlíku MeSH
• kyselina myristová chemie   metabolismus   MeSH
• Masonův-Pfizerův opičí virus genetika   MeSH
• nukleární magnetická rezonance biomolekulární metody   MeSH
• proteiny virové matrix biosyntéza   genetika   izolace a purifikace   MeSH
• rekombinantní proteiny biosyntéza   izolace a purifikace   MeSH
• transfekce MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• acyltransferasy MeSH
• glycylpeptide N-tetradecanoyltransferase MeSH Prohlížeč
• izotopy dusíku MeSH
• izotopy uhlíku MeSH
• kyselina myristová MeSH
• proteiny virové matrix MeSH
• rekombinantní proteiny MeSH

In 1974, (E)-1-nitropentadec-1-ene, a strong lipophilic contact poison of soldiers of the termite genus Prorhinotermes, was the first-described insect-produced nitro compound. However, its biosynthesis remained unknown. In the present study, we tested the hypothesis that (E)-1-nitropentadec-1-ene biosynthesis originates with condensation of amino acids with tetradecanoic acid. By using in vivo experiments with radiolabeled and deuterium-labeled putative precursors, we show that (E)-1-nitropentadec-1-ene is synthesized by the soldiers from glycine or L-serine and tetradecanoic acid. We propose and discuss three possible biosynthetic pathways.

• Klíčová slova
• Prorhinotermes, biosynthesis, natural products, nitro compounds, termites,
• MeSH
• aminokyseliny chemie   metabolismus   MeSH
• deuterium chemie   MeSH
• Isoptera chemie   metabolismus   MeSH
• izotopové značení MeSH
• kyselina myristová chemie   metabolismus   MeSH
• naftaleny chemie   metabolismus   MeSH
• sfingosin analogy a deriváty   chemie   MeSH
• stereoizomerie MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• 1-nitronaphthalene MeSH Prohlížeč
• aminokyseliny MeSH
• deuterium MeSH
• kyselina myristová MeSH
• naftaleny MeSH
• safingol MeSH Prohlížeč
• sfingosin MeSH

N-terminal myristoylation of retroviral matrix proteins is essential for the targeting of the Gag polyproteins to the plasma membrane. To investigate the effect of the myristoylation on the structure and membrane binding ability of the matrix proteins, it is necessary to prepare their myristoylated forms. We present purification of myristoylated matrix proteins of the mouse mammary tumor virus and murine leukemia virus, two morphogenetically distinct retroviruses. The proteins were expressed in Escherichia coli coexpressing a yeast N-myristoyltransferase. This E. coli expression system yielded a mixture of myristoylated and nonmyristoylated matrix proteins. We established efficient one-step metal affinity purification that enabled to obtain pure myristoylated matrix proteins suitable for structural and functional studies.

• Klíčová slova
• Matrix protein, Mouse mammary tumor virus, Murine leukemia virus, Myristoylation, N-myristoyltransferase, Retrovirus,
• MeSH
• chromatografie afinitní MeSH
• klonování DNA MeSH
• kyselina myristová chemie   metabolismus   MeSH
• myši MeSH
• nukleární magnetická rezonance biomolekulární MeSH
• rekombinantní proteiny chemie   genetika   izolace a purifikace   metabolismus   MeSH
• Retroviridae - proteiny chemie   genetika   izolace a purifikace   metabolismus   MeSH
• retrovirové infekce virologie   MeSH
• virus myší leukemie chemie   genetika   metabolismus   MeSH
• zvířata MeSH
• Check Tag
• myši MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• kyselina myristová MeSH
• rekombinantní proteiny MeSH
• Retroviridae - proteiny MeSH

We studied the oligomeric properties of betaretroviral nonmyristoylated matrix protein (MA) and its R55F mutant from the Mason-Pfizer monkey virus in solution by means of chemical crosslinking and NMR spectroscopy. By analyzing crosslinked products and using concentration-dependent NMR chemical shift mapping, we have proven that the wild-type (WT) MA forms oligomers in solution. Conversely, no oligomerization was observed for the R55F mutant. Structural comparison of MAs explained their different behaviors in solution, concluding that the key residues involved in intermonomeric interaction are exposed in the WT MA but buried in the mutant, preventing the oligomerization of R55F. The final model of oligomerization of the WT MA was derived by concerted use of chemical shift mapping and diffusion-ordered spectroscopy measured on a set of protein samples with varying concentrations. We found that the Mason-Pfizer monkey virus WT MA exists in a monomer-dimer-trimer equilibrium in solution, with the corresponding dissociation constants of 2.3 and 0.24 mM, respectively. Structures of the oligomers calculated with HADDOCK software are closely related to the structures of other retroviral MA trimers.

• MeSH
• difuze MeSH
• elektroforéza v polyakrylamidovém gelu MeSH
• kinetika MeSH
• kvarterní struktura proteinů * MeSH
• kyselina myristová metabolismus   MeSH
• magnetická rezonanční spektroskopie MeSH
• Masonův-Pfizerův opičí virus chemie   MeSH
• molekulární modely MeSH
• molekulární sekvence - údaje MeSH
• multimerizace proteinu účinky léků   MeSH
• mutantní proteiny chemie   MeSH
• oxidace-redukce účinky léků   MeSH
• proteiny virové matrix chemie   MeSH
• reagencia zkříženě vázaná farmakologie   MeSH
• sekvence aminokyselin MeSH
• sekvenční seřazení MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Research Support, N.I.H., Extramural MeSH
• Názvy látek
• kyselina myristová MeSH
• mutantní proteiny MeSH
• proteiny virové matrix MeSH
• reagencia zkříženě vázaná MeSH

Polyomavirus mutants E, Q and H, expressing non-myristylated VP2, were generated by replacing the N-terminal glycine residue with glutamic acid, glutamine or histidine, respectively. Viruses mutated in either VP2 or VP3 translation initiation codons were also prepared. All mutated genomes, when transfected into murine host cells, gave rise to viral particles. Infectivity of VP2- and VP3- viruses, as measured by the number of cells expressing viral antigens, was dramatically diminished, indicative of defects in the early stages of infection. In contrast, the absence of a myristyl moiety on VP2 did not substantially affect the early steps of virus infection. No differences in numbers of cells expressing early or late viral antigens were observed between wild-type (wt) and E or Q myr- viruses during the course of a life cycle. Furthermore, no delay in virus DNA replication was detected. However, when cells were left for longer in culture, the number of infected cells, measured by typical virus bursts, was much lower when mutant rather than wt genomes were used. In situ, cell fractionation studies revealed differences in the interaction of viral particles with host cell structures. The infectivity of mutants was affected not only by loss of the myristyl group on VP2, but also, and to a greater extent, by alterations of the N-terminal amino acid composition.

• MeSH
• antigeny virové biosyntéza   MeSH
• buněčné linie MeSH
• DNA virů biosyntéza   MeSH
• fibroblasty virologie   MeSH
• kapsida genetika   MeSH
• kodon iniciační MeSH
• kyselina myristová metabolismus   MeSH
• mutace MeSH
• myši MeSH
• Polyomavirus genetika   imunologie   fyziologie   MeSH
• replikace DNA MeSH
• replikace viru MeSH
• transfekce MeSH
• virové plášťové proteiny MeSH
• zvířata MeSH
• Check Tag
• myši MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• srovnávací studie MeSH
• Názvy látek
• antigeny virové MeSH
• DNA virů MeSH
• kodon iniciační MeSH
• kyselina myristová MeSH
• virové plášťové proteiny MeSH
• VP2 protein, Polyomavirus MeSH Prohlížeč

The first step in immunoreceptor signaling is represented by ligand-dependent receptor aggregation, followed by receptor phosphorylation mediated by tyrosine kinases of the Src family. Recently, sphingolipid- and cholesterol-rich plasma membrane microdomains, called lipid rafts, have been identified and proposed to function as platforms where signal transduction molecules may interact with the aggregated immunoreceptors. Here we show that aggregation of the receptors with high affinity for immunoglobulin E (FcepsilonRI) in mast cells is accompanied by a co-redistribution of the Src family kinase Lyn. The co-redistribution requires Lyn dual fatty acylation, Src homology 2 (SH2) and/or SH3 domains, and Lyn kinase activity, in cis or in trans. Palmitoylation site-mutated Lyn, which is anchored to the plasma membrane but exhibits reduced sublocalization into lipid rafts, initiates the tyrosine phosphorylation of FcepsilonRI subunits, Syk protein tyrosine kinase, and the linker for activation of T cells, along with an increase in the concentration of intracellular Ca(2+). However, Lyn mutated in both the palmitoylation and myristoylation sites does not anchor to the plasma membrane and is incapable of initiating FcepsilonRI phosphorylation and early signaling events. These data, together with our finding that a constitutively tyrosine-phosphorylated FcepsilonRI does not exhibit an increased association with lipid rafts, suggest that FcepsilonRI phosphorylation and early activation events can be initiated outside of lipid rafts.

• MeSH
• aktivace enzymů MeSH
• antigeny metabolismus   MeSH
• buněčná membrána metabolismus   MeSH
• časové faktory MeSH
• cholesterol metabolismus   MeSH
• detergenty farmakologie   MeSH
• DNA metabolismus   MeSH
• fosforylace MeSH
• fosfotyrosin metabolismus   MeSH
• fragmentace DNA MeSH
• imunoblotting MeSH
• konfokální mikroskopie MeSH
• konformace proteinů MeSH
• krysa rodu Rattus MeSH
• kyselina myristová metabolismus   MeSH
• kyselina palmitová metabolismus   MeSH
• luminescentní proteiny metabolismus   MeSH
• membránové mikrodomény metabolismus   MeSH
• metabolismus lipidů MeSH
• myši MeSH
• oktoxynol farmakologie   MeSH
• precipitinové testy MeSH
• receptory IgE metabolismus   MeSH
• rekombinantní proteiny metabolismus   MeSH
• sfingolipidy metabolismus   MeSH
• signální transdukce MeSH
• skupina kinas odvozených od src-genu chemie   metabolismus   fyziologie   MeSH
• terciární struktura proteinů MeSH
• transfekce MeSH
• tyrosin metabolismus   MeSH
• vápník metabolismus   MeSH
• vazba proteinů MeSH
• vztahy mezi strukturou a aktivitou MeSH
• zelené fluorescenční proteiny MeSH
• zvířata MeSH
• Check Tag
• krysa rodu Rattus MeSH
• myši MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• antigeny MeSH
• cholesterol MeSH
• detergenty MeSH
• DNA MeSH
• fosfotyrosin MeSH
• kyselina myristová MeSH
• kyselina palmitová MeSH
• luminescentní proteiny MeSH
• lyn protein-tyrosine kinase MeSH Prohlížeč
• oktoxynol MeSH
• receptory IgE MeSH
• rekombinantní proteiny MeSH
• sfingolipidy MeSH
• skupina kinas odvozených od src-genu MeSH
• tyrosin MeSH
• vápník MeSH
• zelené fluorescenční proteiny MeSH