The review provides an overview of recent developments and applications of capillary electromigration (CE) methods for the determination of important physicochemical parameters of various (bio)molecules and (bio)particles. These parameters include actual and limiting (absolute) ionic mobilities, effective electrophoretic mobilities, effective charges, isoelectric points, electrokinetic potentials, hydrodynamic radii, diffusion coefficients, relative molecular masses, acidity (ionization) constants, binding constants and stoichiometry of (bio)molecular complexes, changes of Gibbs free energy, enthalpy and entropy and rate constants of chemical reactions and interactions, retention factors and partition and distribution coefficients. For the determination of these parameters, the following CE methods are employed: zone electrophoresis in a free solution or in sieving media, isotachophoresis, isoelectric focusing, affinity electrophoresis, electrokinetic chromatography, and electrochromatography. In the individual sections, the procedures for the determination of the above parameters by the particular CE methods are described.

• Klíčová slova
• acidity constant, binding constant, capillary electrophoresis, electrophoretic mobility, review,
• MeSH
• elektroforéza kapilární * MeSH
• isoelektrická fokusace metody   MeSH
• lidé MeSH
• molekulová hmotnost MeSH
• proteiny analýza   chemie   MeSH
• termodynamika MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• přehledy MeSH
• Názvy látek
• proteiny MeSH

BACKGROUND: Amplification of HER2, a receptor tyrosine kinase and a breast cancer-linked oncogene, is associated with aggressive disease. HER2 protein is localised mostly at the cell membrane, but a fraction translocates to mitochondria. Whether and how mitochondrial HER2 contributes to tumorigenicity is currently unknown. METHODS: We enriched the mitochondrial (mt-)HER2 fraction in breast cancer cells using an N-terminal mitochondrial targeting sequence and analysed how this manipulation impacts bioenergetics and tumorigenic properties. The role of the tyrosine kinase activity of mt-HER2 was assessed in wild type, kinase-dead (K753M) and kinase-enhanced (V659E) mtHER2 constructs. RESULTS: We document that mt-HER2 associates with the oxidative phosphorylation system, stimulates bioenergetics and promotes larger respiratory supercomplexes. mt-HER2 enhances proliferation and invasiveness in vitro and tumour growth and metastatic potential in vivo, in a kinase activity-dependent manner. On the other hand, constitutively active mt-HER2 provokes excessive mitochondria ROS generation, sensitises to cell death, and restricts growth of primary tumours, suggesting that regulation of HER2 activity in mitochondria is required for the maximal pro-tumorigenic effect. CONCLUSIONS: mt-HER2 promotes tumorigenicity by supporting bioenergetics and optimal redox balance.

• Klíčová slova
• HER2, cancer, electron transport chain, mitochondria, reactive oxygen species,
• MeSH
• buněčné dýchání fyziologie   MeSH
• energetický metabolismus MeSH
• karcinogeneze metabolismus   MeSH
• lidé MeSH
• mitochondrie * metabolismus   MeSH
• myši MeSH
• nádorové buněčné linie MeSH
• nádory prsu * metabolismus   genetika   MeSH
• oxidativní fosforylace MeSH
• proliferace buněk MeSH
• reaktivní formy kyslíku metabolismus   MeSH
• receptor erbB-2 * metabolismus   MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• myši MeSH
• ženské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH

The enantiomers of diquats (DQs), a new class of functional organic molecules, were recently separated by capillary electrophoresis (CE) with high resolution up to 11.4 within 5-7 min using randomly sulfated α-, β-, and γ-cyclodextrins (CDs) as chiral selectors. These results indicated strong interactions between dicationic diquats and multiply negatively charged sulfated CDs (S-CDs). However, the binding strength of these interactions was not quantified. For that reason, in this study, affinity CE was applied for the determination of the binding constants and ionic mobilities of the complexes of DQ P- and M-enantiomers with CD chiral selectors in an aqueous medium. The non-covalent interactions of 10 pairs of DQ enantiomers with the above CDs were investigated in a background electrolyte (BGE) composed of 22 mM NaOH, 35 mM H3PO4, pH 2.5, and 0.0-1.0 mM concentrations of CDs. The average apparent binding constant and the average actual ionic mobility of the DQ-CD complexes were determined by nonlinear regression analysis of the dependence of the effective mobility of DQ enantiomers on the concentration of CDs in the BGE. The complexes were found to be relatively strong with the averaged apparent binding constants in the range 13 600-547 400 L/mol.

• Klíčová slova
• affinity capillary electrophoresis, analyte‐selector interaction, diquats, stability constant, sulfated cyclodextrins,
• Publikační typ
• časopisecké články MeSH

Canonical RNA interference (RNAi) is sequence-specific mRNA degradation guided by small interfering RNAs (siRNAs) made by RNase III Dicer from long double-stranded RNA (dsRNA). RNAi roles include gene regulation, antiviral immunity or defense against transposable elements. In mammals, RNAi is constrained by Dicer's adaptation to produce another small RNA class-microRNAs. However, a truncated Dicer isoform (ΔHEL1) supporting RNAi exists in mouse oocytes. A homozygous mutation to express only the truncated ΔHEL1 variant causes dysregulation of microRNAs and perinatal lethality in mice. Here, we report the phenotype and canonical RNAi activity in DicerΔHEL1/wt mice, which are viable, show minimal miRNome changes, but their endogenous siRNA levels are an order of magnitude higher. We show that siRNA production in vivo is limited by available dsRNA, but not by Protein kinase R, a dsRNA sensor of innate immunity. dsRNA expression from a transgene yields sufficient siRNA levels to induce efficient RNAi in heart and muscle. DicerΔHEL1/wt mice with enhanced canonical RNAi offer a platform for examining potential and limits of mammalian RNAi in vivo.

• Klíčová slova
• Dicer, Mirtron, PKR, dsRNA, siRNA,
• Publikační typ
• časopisecké články MeSH

Gcn4p belongs to conserved AP-1 transcription factors involved in many cellular processes, including cell proliferation, stress response, and nutrient availability in yeast and mammals. AP-1 activities are regulated at different levels, such as translational activation or protein degradation, which increases the variability of regulation under different conditions. Gcn4p activity in unstructured yeast liquid cultures increases upon amino acid deficiency and is rapidly eliminated upon amino acid excess. Gcn2p kinase is the major described regulator of Gcn4p that enables GCN4 mRNA translation via the uORFs mechanism. Here, we show that Gcn4p is specifically active in U cells in the upper regions and inactive in L cells in the lower regions of differentiated colonies. Using in situ microscopy in combination with analysis of mutants and strains with GFP at different positions in the translational regulatory region of Gcn4p, we show that cell-specific Gcn4p activity is independent of Gcn2p or other translational or transcriptional regulation. Genetically, biochemically, and microscopically, we identified cell-specific proteasomal degradation as a key mechanism that diversifies Gcn4p function between U and L cells. The identified regulation leading to active Gcn4p in U cells with amino acids and efficient degradation in starved L cells differs from known regulations of Gcn4p in yeast but shows similarities to the activity of AP-1 ATF4 in mammals during insulin signaling. These findings may open new avenues for understanding the parallel activities of Gcn4p/ATF4 and reveal a novel biological role for cell type-specific regulation of proteasome-dependent degradation.IMPORTANCEIn nature, microbes usually live in spatially structured communities and differentiate into precisely localized, functionally specialized cells. The coordinated interplay of cells and their response to environmental changes, such as starvation, followed by metabolic adaptation, is critical for the survival of the entire community. Transcription factor Gcn4p is responsible for yeast adaptation under amino acid starvation in liquid cultures, and its activity is regulated mainly at the level of translation involving Gcn2p kinase. Whether Gcn4p functions in structured communities was unknown. We show that translational regulation of Gcn4p plays no role in the development of colony subpopulations; the main regulation occurs at the level of stabilization of the Gcn4p molecule in the cells of one subpopulation and its proteasomal degradation in the other. This regulation ensures specific spatiotemporal activity of Gcn4p in the colony. Our work highlights differences in regulatory networks in unorganized populations and organized structures of yeast, which in many respects resemble multicellular organisms.

• Klíčová slova
• Saccharomyces cerevisiae, cell-specific regulation, differentiated colonies, proteasomal degradation, spatially structured populations, transcription factor, yeast,
• MeSH
• protein-serin-threoninkinasy metabolismus   genetika   MeSH
• proteolýza MeSH
• proteosyntéza MeSH
• regulace genové exprese u hub * MeSH
• Saccharomyces cerevisiae - proteiny * genetika   metabolismus   MeSH
• Saccharomyces cerevisiae * genetika   metabolismus   MeSH
• stabilita proteinů MeSH
• transkripční faktory bZIP * metabolismus   genetika   MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• GCN2 protein, S cerevisiae MeSH Prohlížeč
• GCN4 protein, S cerevisiae MeSH Prohlížeč
• protein-serin-threoninkinasy MeSH
• Saccharomyces cerevisiae - proteiny * MeSH
• transkripční faktory bZIP * MeSH

Bacteria have evolved structured RNAs that can associate with RNA polymerase (RNAP). Two of them have been known so far-6S RNA and Ms1 RNA but it is unclear if any other types of RNAs binding to RNAP exist in bacteria. To identify all RNAs interacting with RNAP and the primary σ factors, we have established and performed native RIP-seq in Bacillus subtilis, Corynebacterium glutamicum, Streptomyces coelicolor, Mycobacterium smegmatis and the pathogenic Mycobacterium tuberculosis. Besides known 6S RNAs in B. subtilis and Ms1 in M. smegmatis, we detected MTS2823, a homologue of Ms1, on RNAP in M. tuberculosis. In C. glutamicum, we discovered novel types of structured RNAs that associate with RNAP. Furthermore, we identified other species-specific RNAs including full-length mRNAs, revealing a previously unknown landscape of RNAs interacting with the bacterial transcription machinery.

• MeSH
• Bacillus subtilis genetika   metabolismus   MeSH
• bakteriální proteiny * metabolismus   genetika   MeSH
• bakteriální RNA * metabolismus   genetika   MeSH
• Corynebacterium glutamicum genetika   metabolismus   MeSH
• DNA řízené RNA-polymerasy * metabolismus   genetika   MeSH
• genetická transkripce MeSH
• konformace nukleové kyseliny MeSH
• Mycobacterium smegmatis genetika   metabolismus   enzymologie   MeSH
• Mycobacterium tuberculosis genetika   metabolismus   MeSH
• nekódující RNA MeSH
• regulace genové exprese u bakterií MeSH
• sigma faktor * metabolismus   genetika   MeSH
• Streptomyces coelicolor genetika   metabolismus   MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• 6S RNA MeSH Prohlížeč
• bakteriální proteiny * MeSH
• bakteriální RNA * MeSH
• DNA řízené RNA-polymerasy * MeSH
• nekódující RNA MeSH
• sigma faktor * MeSH

Valvular heart disease leads to ventricular pressure and/or volume overload. Pressure overload leads to fibrosis, which might regress with its resolution, but the limits and details of this reverse remodeling are not known. To gain more insight into the extent and nature of cardiac fibrosis in valve disease, we analyzed needle biopsies taken from the interventricular septum of patients undergoing surgery for valve replacement focusing on the expression and distribution of major extracellular matrix protein involved in this process. Proteomic analysis performed using mass spectrometry revealed an excellent correlation between the expression of collagen type I and III, but there was little correlation with the immunohistochemical staining performed on sister sections, which included antibodies against collagen I, III, fibronectin, sarcomeric actin, and histochemistry for wheat germ agglutinin. Surprisingly, the immunofluorescence intensity did not correlate significantly with the gold standard for fibrosis quantification, which was performed using Picrosirius Red (PSR) staining, unless multiplexed on the same tissue section. There was also little correlation between the immunohistochemical markers and pressure gradient severity. It appears that at least in humans, the immunohistochemical pattern of fibrosis is not clearly correlated with standard Picrosirius Red staining on sister sections or quantitative proteomic data, possibly due to tissue heterogeneity at microscale, comorbidities, or other patient-specific factors. For precise correlation of different types of staining, multiplexing on the same section is the best approach.

• Klíčová slova
• Collagen, Fibronectin, Fibrosis, Pressure overload, Valvular heart disease,
• MeSH
• aortální insuficience metabolismus   patologie   chirurgie   MeSH
• aortální stenóza * metabolismus   patologie   chirurgie   MeSH
• extracelulární matrix - proteiny * metabolismus   analýza   MeSH
• fibróza * metabolismus   patologie   MeSH
• lidé středního věku MeSH
• lidé MeSH
• mezikomorová přepážka patologie   metabolismus   MeSH
• senioři MeSH
• Check Tag
• lidé středního věku MeSH
• lidé MeSH
• mužské pohlaví MeSH
• senioři MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• extracelulární matrix - proteiny * MeSH

Advanced vibrational spectroscopic experiments have reached a level of sophistication that can only be matched by numerical simulations in order to provide an unequivocal analysis, a crucial step to understand the structure-function relationship of biomolecules. While density functional theory (DFT) has become the standard method when targeting medium-size or larger systems, the problem of its reliability and accuracy are well-known and have been abundantly documented. To establish a reliable computational protocol, especially when accuracy is critical, a tailored benchmark is usually required. This is generally done over a short list of known candidates, with the basis set often fixed a priori. In this work, we present a systematic study of the performance of DFT-based hybrid and double-hybrid functionals in the prediction of vibrational energies and infrared intensities at the harmonic level and beyond, considering anharmonic effects through vibrational perturbation theory at the second order. The study is performed for the six-lowest energy glycine conformers, utilizing available "state-of-the-art" accurate theoretical and experimental data as reference. Focusing on the most intense fundamental vibrations in the mid-infrared range of glycine conformers, the role of the basis sets is also investigated considering the balance between computational cost and accuracy. Targeting larger systems, a broad range of hybrid schemes with different computational costs is also tested.

• Klíčová slova
• DFT, VPT2, benchmark, biomolecules, database, vibrational spectroscopy,
• Publikační typ
• časopisecké články MeSH

The thermo- and pain-sensitive Transient Receptor Potential Melastatin 3 and 8 (TRPM3 and TRPM8) ion channels are functionally associated in the lipid rafts of the plasma membrane. We have already described that cholesterol and sphingomyelin depletion, or inhibition of sphingolipid biosynthesis decreased the TRPM8 but not the TRPM3 channel opening on cultured sensory neurons. We aimed to test the effects of lipid raft disruptors on channel activation on TRPM3- and TRPM8-expressing HEK293T cells in vitro, as well as their potential analgesic actions in TRPM3 and TRPM8 channel activation involving acute pain models in mice. CHO cell viability was examined after lipid raft disruptor treatments and their effects on channel activation on channel expressing HEK293T cells by measurement of cytoplasmic Ca2+ concentration were monitored. The effects of treatments were investigated in Pregnenolone-Sulphate-CIM-0216-evoked and icilin-induced acute nocifensive pain models in mice. Cholesterol depletion decreased CHO cell viability. Sphingomyelinase and methyl-beta-cyclodextrin reduced the duration of icilin-evoked nocifensive behavior, while lipid raft disruptors did not inhibit the activity of recombinant TRPM3 and TRPM8. We conclude that depletion of sphingomyelin or cholesterol from rafts can modulate the function of native TRPM8 receptors. Furthermore, sphingolipid cleavage provided superiority over cholesterol depletion, and this method can open novel possibilities in the management of different pain conditions.

• Klíčová slova
• Transient Receptor Potential, cholesterol, lipid raft, methyl-beta-cyclodextrin, pain, sphingomyelinase,
• MeSH
• analgetika farmakologie   terapeutické užití   MeSH
• beta-cyklodextriny * farmakologie   MeSH
• bolest farmakoterapie   metabolismus   MeSH
• CHO buňky MeSH
• cholesterol metabolismus   MeSH
• Cricetulus * MeSH
• HEK293 buňky MeSH
• kationtové kanály TRPM * metabolismus   genetika   MeSH
• lidé MeSH
• membránové mikrodomény metabolismus   účinky léků   MeSH
• modely nemocí na zvířatech * MeSH
• myši MeSH
• pregnenolon farmakologie   MeSH
• sfingomyelinfosfodiesterasa * metabolismus   MeSH
• viabilita buněk účinky léků   MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• mužské pohlaví MeSH
• myši MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• analgetika MeSH
• beta-cyklodextriny * MeSH
• cholesterol MeSH
• kationtové kanály TRPM * MeSH
• methyl-beta-cyclodextrin MeSH Prohlížeč
• pregnenolon MeSH
• pregnenolone sulfate MeSH Prohlížeč
• sfingomyelinfosfodiesterasa * MeSH
• TRPM3 protein, mouse MeSH Prohlížeč
• TRPM8 protein, mouse MeSH Prohlížeč

Since 1975, the incidence of obesity has increased to epidemic proportions, and the number of patients with obesity has quadrupled. Obesity is a major risk factor for developing other serious diseases, such as type 2 diabetes mellitus, hypertension, and cardiovascular diseases. Recent epidemiologic studies have defined obesity as a risk factor for the development of neurodegenerative diseases, such as Alzheimer's disease (AD) and other types of dementia. Despite all these serious comorbidities associated with obesity, there is still a lack of effective antiobesity treatment. Promising candidates for the treatment of obesity are anorexigenic neuropeptides, which are peptides produced by neurons in brain areas implicated in food intake regulation, such as the hypothalamus or the brainstem. These peptides efficiently reduce food intake and body weight. Moreover, because of the proven interconnection between obesity and the risk of developing AD, the potential neuroprotective effects of these two agents in animal models of neurodegeneration have been examined. The objective of this review was to explore anorexigenic neuropeptides produced and acting within the brain, emphasizing their potential not only for the treatment of obesity but also for the treatment of neurodegenerative disorders.

• Klíčová slova
• Alzheimer´s-like pathology, anorexigenic neuropeptides, antiobesity treatment, neuroprotection,
• MeSH
• Alzheimerova nemoc farmakoterapie   metabolismus   patologie   prevence a kontrola   MeSH
• hypothalamus účinky léků   metabolismus   patologie   MeSH
• látky proti obezitě * farmakologie   terapeutické užití   MeSH
• lidé MeSH
• mozek účinky léků   metabolismus   patologie   MeSH
• neurodegenerativní nemoci farmakoterapie   metabolismus   prevence a kontrola   MeSH
• neuropeptidy * metabolismus   farmakologie   terapeutické užití   MeSH
• neuroprotektivní látky * farmakologie   terapeutické užití   MeSH
• obezita * farmakoterapie   metabolismus   MeSH
• přijímání potravy účinky léků   MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• přehledy MeSH
• Názvy látek
• látky proti obezitě * MeSH
• neuropeptidy * MeSH
• neuroprotektivní látky * MeSH