1461 research outputs found
Sort by
Ternary Cu(II) Complex with GHK Peptide and Cis-Urocanic Acid as a Potential Physiologically Functional Copper Chelate
Get PDFThe tripeptide NH2-Gly-His-Lys-COOH (GHK), cis-urocanic acid (cis-UCA) and Cu(II) ions are physiological constituents of the human body and they co-occur (e.g., in the skin and the plasma). While GHK is known as Cu(II)-binding molecule, we found that urocanic acid also coordinates Cu(II) ions. Furthermore, both ligands create ternary Cu(II) complex being probably physiologically functional species. Regarding the natural concentrations of the studied molecules in some human tissues, together with the affinities reported here, we conclude that the ternary complex [GHK][Cu(II)][cis-urocanic acid] may be partly responsible for biological effects of GHK and urocanic acid described in the literature
Unsymmetrically Substituted Dibenzo[b,f][1,5]-diazocine-6,12(5H,11H)dione—A Convenient Scaffold for Bioactive Molecule Design
Get PDFA novel approach for the synthesis of unsymmetrically substituted dibenzo[b,f][1,5]diazocine-6,12(5H,11H)diones has been developed. This facile three-step method uses variously substituted 1H-benzo[d][1,3]oxazine-2,4-diones (isatoic anhydrides) and 2-aminobenzoic acids as a starting materials. The obtained products were further transformed into N-alkyl-, N-acetyl- and dithio analogues. Developed procedures allowed the synthesis of unsymmetrical dibenzo[b,f][1,5]diazocine-6,12(5H,11H)diones and three novel heterocyclic scaffolds: benzo[b]naphtho[2,3-f][1,5]diazocine-6,14(5H,13H)dione, pyrido[3,2-c][1,5]benzodiazocine-5,11(6H,12H)-dione and pyrazino[3,2-c][1,5]benzodiazocine-6,12(5H,11H)dione. For 11 of the compounds crystal structures were obtained. The preliminary cytotoxic effect against two cancer (HeLa, U87) and two normal lines (HEK293, EUFA30) as well as antibacterial activity were determined. The obtained dibenzo[b,f][1,5]diazocine(5H,11H)6,12-dione framework could serve as a privileged structure for the drug design and development
Pathogenic Effect of GDAP1 Gene Mutations in a Yeast Model
Get PDFThe question of whether a newly identified sequence variant is truly a causative mutation is a central problem of modern clinical genetics. In the current era of massive sequencing, there is an urgent need to develop new tools for assessing the pathogenic effect of new sequence variants. In Charcot-Marie-Tooth disorders (CMT) with their extreme genetic heterogeneity and relatively homogenous clinical presentation, addressing the pathogenic effect of rare sequence variants within 80 CMT genes is extremely challenging. The presence of multiple rare sequence variants within a single CMT-affected patient makes selection for the strongest one, the truly causative mutation, a challenging issue. In the present study we propose a new yeast-based model to evaluate the pathogenic effect of rare sequence variants found within the one of the CMT-associated genes, GDAP1. In our approach, the wild-type and pathogenic variants of human GDAP1 gene were expressed in yeast. Then, a growth rate and mitochondrial morphology and function of GDAP1-expressing strains were studied. Also, the mutant GDAP1 proteins localization and functionality were assessed in yeast. We have shown, that GDAP1 was not only stably expressed but also functional in yeast cell, as it influenced morphology and function of mitochondria and altered the growth of a mutant yeast strain. What is more, the various GDAP1 pathogenic sequence variants caused the specific for them effect in the tests we performed. Thus, the proposed model is suitable for validating the pathogenic effect of known GDAP1 mutations and may be used for testing of unknown sequence variants found in CMT patients
The Role of Selective Protein Degradation in the Regulation of Iron and Sulfur Homeostasis in Plants
Get PDFPlants are able to synthesize all essential metabolites from minerals, water, and light to complete their life cycle. This plasticity comes at a high energy cost, and therefore, plants need to tightly allocate resources in order to control their economy. Being sessile, plants can only adapt to fluctuating environmental conditions, relying on quality control mechanisms. The remodeling of cellular components plays a crucial role, not only in response to stress, but also in normal plant development. Dynamic protein turnover is ensured through regulated protein synthesis and degradation processes. To e�ectively target a wide range of proteins for degradation, plants utilize two mechanistically-distinct, but largely complementary systems: the 26S proteasome and the autophagy. As both proteasomaland
autophagy-mediated protein degradation use ubiquitin as an essential signal of substrate recognition, they share ubiquitin conjugation machinery and downstream ubiquitin recognition modules. Recent progress has been made in understanding the cellular homeostasis of iron and sulfur
metabolisms individually, and growing evidence indicates that complex crosstalk exists between iron and sulfur networks. In this review, we highlight the latest publications elucidating the role of selective protein degradation in the control of iron and sulfur metabolism during plant development, as well as environmental stresses
Epigenetic Landmarks of Leaf Senescence and Crop Improvement.
Get PDFThis review synthesizes knowledge on epigenetic regulation of leaf senescence and discusses the possibility of using this knowledge to improve crop quality. This control level is implemented by different but interacting epigenetic mechanisms, including DNA methylation, covalent histone modifications, and non-covalent chromatin remodeling. The genetic and epigenetic changes may act alone or together and regulate the gene expression, which may result in heritable (stress memory) changes and may lead to crop survival. In the review, the question also arises whether the mitotically stable epigenetic information can be used for crop improvement. The barley crop model for early and late events of dark-induced leaf senescence (DILS), where the point of no return was defined, revealed differences in DNA and RNA modifications active in DILS compared to developmental leaf senescence. This suggests the possibility of a yet-to-be-discovered epigenetic-based switch between cell survival and cell death. Conclusions from the analyzed research contributed to the hypothesis that chromatin-remodeling mechanisms play a role in the control of induced leaf senescence. Understanding this mechanism in crops might provide a tool for further exploitation toward sustainable agriculture: so-called epibreeding
Nostoc edaphicum CCNP1411 from the Baltic Sea—A New Producer of Nostocyclopeptides
Get PDFNostocyclopeptides (Ncps) constitute a small class of nonribosomal peptides, exclusivelyproduced by cyanobacteria of the genusNostoc. The peptides inhibit the organic anion transporters,OATP1B3 and OATP1B1, and prevent the transport of the toxic microcystins and nodularin intohepatocytes. So far, only three structural analogues, Ncp-A1, Ncp-A2 and Ncp-M1, and their linearforms were identified inNostocstrains as naturally produced cyanometabolites. In the current work,the whole genome sequence of the new Ncps producer,N.edaphicumCCNP1411 from the BalticSea, has been determined. The genome consists of the circular chromosome (7,733,505 bps) andfive circular plasmids (from 44.5 kb to 264.8 kb). The nostocyclopeptide biosynthetic gene cluster(located between positions 7,609,981–7,643,289 bps of the chromosome) has been identified andcharacterizedin silico. The LC-MS/MS analyzes ofN.edaphicumCCNP1411 cell extracts preparedin aqueous methanol revealed several products of the genes. Besides the known peptides, Ncp-A1and Ncp-A2, six other compounds putatively characterized as new noctocyclopeptide analogueswere detected. This includes Ncp-E1 and E2 and their linear forms (Ncp-E1-L and E2-L), a cyclicNcp-E3 and a linear Ncp-E4-L. Regardless of the extraction conditions, the cell contents of the linearnostocyclopeptides were found to be higher than the cyclic ones, suggesting a slow rate of themacrocyclization process
Antibacterial Peptide Nucleic Acids—Facts and Perspectives
Get PDFAntibiotic resistance is an escalating, worldwide problem. Due to excessive use of
antibiotics, multidrug‐resistant bacteria have become a serious threat and a major global healthcare
problem of the 21st century. This fact creates an urgent need for new and effective antimicrobials.
The common strategies for antibiotic discovery are based on either modifying existing antibiotics or
screening compound libraries, but these strategies have not been successful in recent decades. An
alternative approach could be to use gene‐specific oligonucleotides, such as peptide nucleic acid
(PNA) oligomers, that can specifically target any single pathogen. This approach broadens the range
of potential targets to any gene with a known sequence in any bacterium, and could significantly
reduce the time required to discover new antimicrobials or their redesign, if resistance arises. We
review the potential of PNA as an antibacterial molecule. First, we describe the physicochemical
properties of PNA and modifications of the PNA backbone and nucleobases. Second, we review the
carriers used to transport PNA to bacterial cells. Furthermore, we discuss the PNA targets in
antibacterial studies focusing on antisense PNA targeting bacterial mRNA and rRNA
Expression of maize Calcium-Dependent Protein Kinase (ZmCPK11) improves salt tolerance in transgenic Arabidopsis plants by regulating sodium and potassium homeostasis and stabilizing photosystem II
Get PDFIn plants, CALCIUM-DEPENDENT PROTEIN KINASES (CDPKs/CPKs) are involved in calcium signaling in response to endogenous and environmental stimuli. Here, we report that ZmCPK11, one of maize CDPKs, participates in salt stress response and tolerance. Salt stress induced expression and upregulated the activity of ZmCPK11 in maize roots and leaves. Activation of ZmCPK11 upon salt stress was also observed in roots and leaves of transgenic Arabidopsis plants expressing ZmCPK11. The transgenic plants showed a long-root phenotype under control conditions and a short-root phenotype under NaCl, abscisic acid (ABA) or jasmonic acid (JA) treatment. Analysis of ABA and JA content in roots indicated that ZmCPK11 can mediate root growth by regulating the levels of these phytohormones. Moreover, 4-week-old transgenic plants were more tolerant to salinity than the wild-type plants. Their leaves were less chlorotic and showed weaker symptoms of senescence accompanied by higher chlorophyll content and higher quantum efficiency of photosystem II. The expression of Na+/K+ transporters (HKT1, SOS1 and NHX1) and transcription factors (CBF1, CBF2, CBF3, ZAT6 and ZAT10) with known links to salinity tolerance was upregulated in roots of the transgenic plants upon salt stress. Furthermore, the transgenic plants accumulated less Na+ in roots and leaves under salinity, and showed a higher K+/Na+ ratio in leaves. These results show that the improved salt tolerance in ZmCPK11-transgenic plants could be due to an upregulation of genes involved in the maintenance of intracellular Na+ and K+ homeostasis and a protection of photosystem II against damage
Hereditary xerocytosis - spectrum and clinical manifestations of variants in the PIEZO1 gene, including co-occurrence with a novel β-globin mutation
Get PDFHereditary xerocytosis (HX) is a rare, autosomal dominant congenital hemolytic anemia (CHA) characterized by
erythrocyte dehydration with presentation of various degrees of hemolytic anemia. HX is often misdiagnosed as
hereditary spherocytosis or other CHA. Here we report three cases of suspected HX and one case of HX associated
with β-thalassemia.
Sanger method was used for sequencing cDNA of the PIEZO1 gene. Variants were evaluated for potential
pathogenicity by MutationTaster, PROVEAN, PolyPhen-2 and M-CAP software, and by molecular modeling.
Four different variants in the PIEZO1 gene were found, including three substitutions (p.D669H, p.D1566G,
p.T1732 M) and one deletion (p.745delQ). In addition, in the patient with the p.T1732 M variant we detected a
12-nucleotide deletion in the β-globin gene leading to a deletion of amino acids 62AHGK65. The joint presence
of mutations in two different genes connected with erythrocytes markedly aggravated the presentation of the
disease. Bioinformatic analysis and molecular modeling strongly indicated likely deleterious effects of all four
PIEZO1 variants, but co-segregation analysis showed that the p.D1566G substitution is in fact non-pathogenic.
Identification of causative mutations should improve the diagnosis and management of HX and provide a new
insight into the molecular basis of this complex red blood cell abnormality
ATP Synthase Subunit a Supports Permeability Transition in Yeast Lacking Dimerization Subunits and Modulates yPTP Conductance
Get PDFBackground/Aims: Mitochondrial ATP synthase, in addition to being involved in ATP synthesis, is involved in permeability transition pore (PTP) formation, which precedes apoptosis in mammalian cells and programmed cell death in yeast. Mutations in genes encoding ATP synthase subunits cause neuromuscular disorders and have been identified in cancer samples. PTP is also involved in pathology. We previously found that in Saccharomyces cerevisiae,two mutations in ATP synthase subunit a (atp6-P163S and atp6-K90E, equivalent to those detected in prostate and thyroid cancer samples, respectively) in the OM45-GFP background affected ROS and calcium homeostasis and delayed yeast PTP (yPTP) induction upon calcium treatment by modulating the dynamics of ATP synthase dimer/oligomer formation. The Om45 protein is a component of the porin complex, which is equivalent to mammalian VDAC. We aimed to investigate yPTP function in atp6-P163S and atp6-K90E mutants lacking the e and g dimerization subunits of ATP synthase. Methods: Triple mutants with the atp6-P163S or atp6-K90E mutation, the OM45-GFP gene and deletion of the TIM11 gene encoding subunit ewere constructed by crossing and tetrad dissection. In spores capable of growing, the original atp6 mutations reverted to wild type, and two compensatory mutations, namely, atp6-C33S-T215C, were selected. The effects of these mutations on cellular physiology, mitochondrial morphology, bioenergetics and permeability transition (PT) were analyzed by fluorescence and electron microscopy, mitochondrial respiration, ATP synthase activity, calcium retention capacity and swelling assays. Results: The atp6-C33S-T215Cmutationsin the OM45-GFPbackground led to delayed growth at elevated temperature on both fermentative and respiratory media and increased sensitivity to high calcium ions concentration or hydrogen peroxide in the medium. The ATP synthase activity was reduced by approximately 50% and mitochondrial network was hyperfused in these cells grown at elevated temperature. The atp6-C33S-T215Cstabilized ATP synthase dimers and restored the yPTP properties in Tim11∆ cells. In OM45-GFP cells, in which Tim11 is present, these mutations increased the fraction of swollen mitochondria by up to 85% vs 60% in the wild type, although the time required for calcium release doubled. Conclusion: ATP synthase subunit e is essential in the S. cerevisiaeatp6-P163S and atp6-K90E mutants. In addition to subunits e and g, subunit a is critical for yPTP induction and conduction. The increased yPTP conduction decrease the S. cerevisiae cell fitness