Functional properties of the Su(Hw) complex are determined by its regulatory environment and multiple interactions on the Su(Hw) protein platform

The Su(Hw) protein was first identified as a DNA-binding component of an insulator complex in Drosophila. Insulators are regulatory elements that can block the enhancer-promoter communication and exhibit boundary activity. Some insulator complexes contribute to the higher-order organization of chromatin in topologically associated domains that are fundamental elements of the eukaryotic genomic structure. The Su(Hw)-dependent protein complex is a unique model for studying the insulator, since its basic structural components affecting its activity are already known. However, the mechanisms involving this complex in various regulatory processes and the precise interaction between the components of the Su(Hw) insulators remain poorly understood. Our recent studies reveal the fine mechanism of formation and function of the Su(Hw) insulator. Our results provide, for the first time, an example of a high complexity of interactions between the insulator proteins that are required to form the (Su(Hw)/Mod(mdg4)-67.2/CP190) complex. All interactions between the proteins are to a greater or lesser extent redundant, which increases the reliability of the complex formation. We conclude that both association with CP190 and Mod(mdg4)-67.2 partners and the proper organization of the DNA binding site are essential for the efficient recruitment of the Su(Hw) complex to chromatin insulators. In this review, we demonstrate the role of multiple interactions between the major components of the Su(Hw) insulator complex (Su(Hw)/Mod(mdg4)-67.2/CP190) in its activity. It was shown that Su(Hw) may regulate the enhancer–promoter communication via the newly described insulator neutralization mechanism. Moreover, Su(Hw) participates in direct regulation of activity of vicinity promoters. Finally, we demonstrate the mechanism of organization of “insulator bodies” and suggest a model describing their role in proper binding of the Su(Hw) complex to chromatin

THE REASON FOR MECHANICAL PROPERTIES ANISOTROPY OF HOT ROLLED 6061 ALUMINUM ALLOY PLATE

Исследована анизотропия механических свойств горячекатаной плиты из сплава 6061 системы Al–Mg–Si после различных скоростных режимов прокатки. Прочностные свойства во всех случаях максимальны поперек направления прокатки и минимальны под углом 45º. Снижение скорости прокатки приводит к большему упрочнению. Анизотропия прочностных механических свойств горячекатаной алюминиевой плиты в основном определяется текстурой материала, показателем которой является усредненный по ориентировкам фактор Тейлора. Пластические свойства плиты оказались практически изотропными.Anisotropy of mechanical properties of alloy 6061 Al–Mg–Si system plate was studied after various speed rolling regimes. Structural behavior of all cases is maximized across rolling direction and minimal at an angle of 45°. Reduction of rolling speed leads to high hardening. The anisotropy of strength mechanical properties of rolled aluminum plate is mainly determined by material texture, which is average value with orientation of Taylor factor. Plastic properties of the plate were almost isotopic.Работа выполнена в рамках проектной темы Минобрнауки РФ (задание № 11.1465.2014/K) и гранта РФФИ (№ 16-32-00030 мол_а). Авторы выражают признательность за содействие программе поддержки ведущих университетов РФ в целях повышения их конкурентоспособности №211 Правительства РФ № 02.А03.21.0006

Reversible and Irreversible Interactions of Poly(3-hexylthiophene) with Oxygen Studied by Spin-Sensitive Methods

Understanding of degradation mechanisms in polymer:fullerene bulk-heterojunctions on the microscopic level aimed at improving their intrinsic stability is crucial for the breakthrough of organic photovoltaics. These materials are vulnerable to exposure to light and/or oxygen, hence they involve electronic excitations. To unambiguously probe the excited states of various multiplicities and their reactions with oxygen, we applied combined magneto-optical methods based on multifrequency (9 and 275 GHz) electron paramagnetic resonance (EPR), photoluminescence (PL), and PL-detected magnetic resonance (PLDMR) to the conjugated polymer poly(3-hexylthiophene) (P3HT) and polymer:fullerene bulk heterojunctions (P3HT:PCBM; PCBM = [6,6]-phenyl-C61-butyric acid methyl ester). We identified two distinct photochemical reaction routes, one being fully reversible and related to the formation of polymer:oxygen charge transfer complexes, the other one, irreversible, being related to the formation of singlet oxygen under participation of bound triplet excitons on the polymer chain. With respect to the blends, we discuss the protective effect of the methanofullerenes on the conjugated polymer bypassing the triplet exciton generation

DNA Topoisomerase II Modulates Insulator Function in Drosophila

Insulators are DNA sequences thought to be important for the establishment and maintenance of cell-type specific nuclear architecture. In Drosophila there are several classes of insulators that appear to have unique roles in gene expression. The mechanisms involved in determining and regulating the specific roles of these insulator classes are not understood. Here we report that DNA Topoisomerase II modulates the activity of the Su(Hw) insulator. Downregulation of Topo II by RNAi or mutations in the Top2 gene result in disruption of Su(Hw) insulator function. This effect is mediated by the Mod(mdg4)2.2 protein, which is a unique component of the Su(Hw) insulator complex. Co-immunoprecipitation and yeast two-hybrid experiments show that Topo II and Mod(mdg4)2.2 proteins directly interact. In addition, mutations in Top2 cause a slight decrease of Mod(mdg4)2.2 transcript but have a dramatic effect on Mod(mdg4)2.2 protein levels. In the presence of proteasome inhibitors, normal levels of Mod(mdg4)2.2 protein and its binding to polytene chromosomes are restored. Thus, Topo II is required to prevent Mod(mdg4)2.2 degradation and, consequently, to stabilize Su(Hw) insulator-mediated chromatin organization

THE SURGICAL STAGE OF PULMONARY TUBERCULOSIS TREATMENT USING MOLECULAR-GENETIC METHODS TO TEST SUSCEPTIBILITY TO RIFAMPICIN

The objective of the study: to analyze the frequency and patterns of drug resistance of Mycobacterium tuberculosis (MTB) according to the results of microbiological tests of surgical specimens of the patients who underwent surgery due to tuberculosis, and to compare them with the results of sputum tests done in the pre-operative period. Subjects and methods. The data of surgical specimens from 170 patients operated due to tuberculosis were analyzed. The surgical specimens were sent for histological and microbiological tests (detection of MTB DNA and rifampicin resistance by GeneXpert, culture on solid media with drug sensitivity testing). Results. The molecular genetic testing of surgical specimens by GeneXpert was highly effective for detection of rifampicin resistance; in 97.8% of cases, there was a match with the results of sputum culture with consecutive DST performed before the surgery. Molecular genetic tests of surgical specimens allowed detecting MTB DNA in 66.1% of patients in whom no MTB or MTB DNA was detected in sputum and bronchial washings prior to the surgery, and of them in 28.2% of cases, rifampicin resistance was detected, which was unknown before the surgery. These data allowed prescribing adequate chemotherapy immediately after surgery