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Rif1 is a large multifaceted protein involved in various processes of DNA metabolism - from telomere length regulation and replication to double-strand break repair. The mechanistic details of its action, however, are often poorly understood. Here, we report functional characterization of the Rif1 homologue from methylotrophic thermotolerant budding yeast Hansenula polymorpha DL-1. We show that, similar to other yeast species, H. polymorpha Rif1 suppresses telomerase-dependent telomere elongation. We uncover two novel modes of Rif1 recruitment at H. polymorpha telomeres: via direct DNA binding and through the association with the Ku heterodimer. Both of these modes (at least partially) require the intrinsically disordered N-terminal extension - a region of the protein present exclusively in yeast species. We also demonstrate that Rif1 binds Stn1 and promotes its accumulation at telomeres in H. polymorpha ., Competing Interests: AM, OP, MZ, VP, OD No competing interests declared, (© 2022, Malyavko et al.)

HUWE1 is a universal quality-control E3 ligase that marks diverse client proteins for proteasomal degradation. Although the giant HECT enzyme is an essential component of the ubiquitin-proteasome system closely linked with severe human diseases, its molecular mechanism is little understood. Here, we present the crystal structure of Nematocida HUWE1, revealing how a single E3 enzyme has specificity for a multitude of unrelated substrates. The protein adopts a remarkable snake-like structure, where the C-terminal HECT domain heads an extended alpha-solenoid body that coils in on itself and houses various protein-protein interaction modules. Our integrative structural analysis shows that this ring structure is highly dynamic, enabling the flexible HECT domain to reach protein targets presented by the various acceptor sites. Together, our data demonstrate how HUWE1 is regulated by its unique structure, adapting a promiscuous E3 ligase to selectively target unassembled orphan proteins., (© 2021. The Author(s), under exclusive licence to Springer Nature America, Inc.)

Williams-Beuren syndrome, characterized by numerous physiological and mental problems, is caused by the heterozygous deletion of chromosome region 7q11.23, which results in the disappearance of 26 protein-coding genes. Protein WBSCR27 is a product of one of these genes whose biological function has not yet been established and for which structural information has been absent until now. Using NMR, we investigated the structural and functional properties of murine WBSCR27. For protein in the apo form and in a complex with S-(5'-adenosyl)-l-homocysteine (SAH), a complete NMR resonance assignment has been obtained and the secondary structure has been determined. This information allows us to attribute WBSCR27 to Class I methyltransferases. The interaction of WBSCR27 with the cofactor S-(5'-adenosyl)-l-methionine (SAM) and its metabolic products - SAH, 5'-deoxy-5'-methylthioadenosine (MTA) and 5'-deoxyadenosine (5'dAdo) - was studied by NMR and isothermal titration calorimetry. SAH binds WBSCR27 much tighter than SAM, leaving open the question of cofactor turnover in the methylation reaction. One possible answer to this question is the presence of weak but detectable nucleosidase activity for WBSCR27. We found that the enzyme catalyses the cleavage of the adenine moiety from SAH, MTA and 5'dAdo, similar to the action of bacterial SAH/MTA nucleosidases. We also found that the binding of SAM or SAH causes a significant change in the structure of WBSCR27 and in the conformational mobility of the protein fragments, which can be attributed to the substrate recognition site. This indicates that the binding of the cofactor modulates the folding of the substrate-recognizing region of the enzyme., (© 2020 Federation of European Biochemical Societies.)

Immune response may play a pivotal role in the pathogenesis of the common synucleinopathy as Parkinson's disease (PD) and could be mediated with the accumulation of neurotoxic alpha-synuclein. There is limited evidence for immune response in another synucleinopathy as dementia with Lewy bodies (DLB). Recent data suggest that immune response may contribute to cognitive impairment. We aimed to estimate plasma cytokine profile in patients with synucleinopathies with dementia (PD dementia (PDD), DLB). Plasma cytokine levels (interferon-gamma (IFN-gamma), interleukin (IL)-4 (IL-4), IL-6, IL-10, tumor necrosis factor alpha (TNF-alpha), monocyte chemoattractant protein-1 (MCP-1)). were estimated in 16 patients with DLB, 19 patients with PDD, 28 patients with PD without dementia (PD) and 19 individuals without neurological disorders (controls) using Luminex array system. Cognitive status was assessed with the Mini-Mental State Examination (MMSE). TNF-alpha and IL-6 plasma levels were elevated in patients with synucleinopathies with dementia (DLB, PDD) compared to controls and IL-10 plasma level was increased in PDD compared to controls (p < 0.05). IFN-gamma levels were decreased in PD and PDD patients compared to controls (p < 0.001, p = 0.026, respectively) and in PD patients than in DLB patients (p = 0.032). Patients with PD, PDD, and DLB were characterized by increased plasma levels of MCP-1 compared to controls (p < 0.001). At the same time, no differences in TNF-alpha, IL-10, IL-6 plasma levels in PD patients compared to controls were found. Our study demonstrated more pronounced immune response in synucleinopathies associated with dementia compared to PD without demetia., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2020 Elsevier Ltd. All rights reserved.)

Telomerase is a ribonucleoprotein enzyme, which maintains genome integrity in eukaryotes and ensures continuous cellular proliferation. Telomerase holoenzyme from the thermotolerant yeast Hansenula polymorpha, in addition to the catalytic subunit (TERT) and telomerase RNA (TER), contains accessory proteins Est1 and Est3, which are essential for in vivo telomerase function. Here we report the high-resolution structure of Est3 from Hansenula polymorpha (HpEst3) in solution, as well as the characterization of its functional relationships with other components of telomerase. The overall structure of HpEst3 is similar to that of Est3 from Saccharomyces cerevisiae and human TPP1. We have shown that telomerase activity in H. polymorpha relies on both Est3 and Est1 proteins in a functionally symmetrical manner. The absence of either Est3 or Est1 prevents formation of a stable ribonucleoprotein complex, weakens binding of a second protein to TER, and decreases the amount of cellular TERT, presumably due to the destabilization of telomerase RNP. NMR probing has shown no direct in vitro interactions of free Est3 either with the N-terminal domain of TERT or with DNA or RNA fragments mimicking the probable telomerase environment. Our findings corroborate the idea that telomerase possesses the evolutionarily variable functionality within the conservative structural context.

The telomere regulator and transcription factor Rap1 is the only telomere protein conserved in yeasts and mammals. Its functional repertoire in budding yeasts is a particularly interesting field for investigation, given the high evolutionary diversity of this group of unicellular organisms. In the methylotrophic thermotolerant species Hansenula polymorpha DL-1 the RAP1 gene is duplicated (HpRAP1A and HpRAP1B). Here, we report the functional characterization of the two paralogues from H. polymorpha DL-1. We uncover distinct (but overlapping) DNA binding preferences of HpRap1A and HpRap1B proteins. We show that only HpRap1B is able to recognize telomeric DNA directly and to protect it from excessive recombination, whereas HpRap1A is associated with subtelomere regions. Furthermore, we identify specific binding sites for both HpRap1A and HpRap1B within promoters of a large number of ribosomal protein genes (RPGs), implicating Rap1 in the control of the RP regulon in H. polymorpha. Our bioinformatic analysis suggests that RAP1 was duplicated early in the evolution of the "methylotrophs" clade, and the two genes evolved independently. Therefore, our characterization of Rap1 paralogues in H. polymorpha may be relevant to other "methylotrophs", yielding valuable insights into the evolution of budding yeasts.

Williams-Beuren syndrome is a genetic disorder characterized by physiological and mental abnormalities, and is caused by hemizygous deletion of several genes in chromosome 7. One of the removed genes encodes the WBSCR27 protein. Bioinformatic analysis of the sequence of WBSCR27 indicates that it belongs to the family of SAM-dependent methyltransferases. However, exact cellular functions of this protein or phenotypic consequences of its deficiency are still unknown. Here we report nearly complete 1 H, 15 N, and 13 C chemical shifts assignments of the 26 kDa WBSCR27 protein from Mus musculus in complex with the cofactor S-adenosyl-L-methionine (SAM). Analysis of the assigned chemical shifts allowed us to characterize the protein's secondary structure and backbone dynamics. The topology of the protein's fold confirms the assumption that the WBSCR27 protein belongs to the family of class I methyltransferases.

Telomerase is a multisubunit ribonucleoprotein enzyme that is essential for continuous cellular proliferation. A key role of telomerase in cancer and ageing makes it a promising target for the development of cancer therapies and treatments of other age-associated diseases, since telomerase allows unlimited proliferation potential of cells in the majority of cancer types. However, the structure and molecular mechanism of telomerase action are still poorly understood. In budding yeast, telomerase consists of the catalytic subunit, the telomerase reverse transcriptase or Est2 protein, telomerase RNA (TLC1) and two regulatory subunits, Est1 and Est3. Each of the four subunits is essential for in vivo telomerase function. Est3 interacts directly with Est1 and Est2, and stimulates Est2 catalytic activity. However, the exact role of the Est3 protein in telomerase function is still unknown. Determination of the structure, dynamic and functional properties of Est3 can bring new insights into the molecular mechanism of telomerase activity. Here we report nearly complete 1 H, 13 C and 15 N resonance assignments of Est3 from the yeast Hansenula polymorpha. Analysis of the assigned chemical shifts allowed us to identify the protein's secondary structure and backbone dynamic properties. Structure-based sequence alignment revealed similarities in the structural organization of yeast Est3 and mammalian TPP1 proteins.

The elongation of single-stranded DNA repeats at the 3'-ends of chromosomes by telomerase is a key process in maintaining genome integrity in eukaryotes. Abnormal activation of telomerase leads to uncontrolled cell division, whereas its down-regulation is attributed to ageing and several pathologies related to early cell death. Telomerase function is based on the dynamic interactions of its catalytic subunit (TERT) with nucleic acids-telomerase RNA, telomeric DNA and the DNA/RNA heteroduplex. Here, we present the crystallographic and NMR structures of the N-terminal (TEN) domain of TERT from the thermotolerant yeast Hansenula polymorpha and demonstrate the structural conservation of the core motif in evolutionarily divergent organisms. We identify the TEN residues that are involved in interactions with the telomerase RNA and in the recognition of the 'fork' at the distal end of the DNA product/RNA template heteroduplex. We propose that the TEN domain assists telomerase biological function and is involved in restricting the size of the heteroduplex during telomere repeat synthesis.

The purpose of our work was to identify the features of the newborn´s microbiota formation during first month of their life on the model of the Tver region. The samples of oral fluid, meconium and feces of the first month newborns were examined in 38 full-term and 21 premature children of both sexes to determine the spectrum and quantity of oral fluid and intestine microorganisms. As the result, it was found that in full-term and vaginally delivered infants the microbiota of the oral cavity and intestine was characterized by greater diversity than in children delivered by C-section, in which Lactobacilli, Bifidobacteria, E. coli, Fusobacteria, Clostridia, and Veilonella were lacked. In premature infants, especially delivered by C-section, there was a sharp decrease in the incidence and number of representatives of normal oral and intestinal microbiota and an increase in opportunistic pathogens, for example yeast fungi of the genus Candida. The efficacy of L. rhamnosus and L.paracasei, isolated from the intestines of newborns, was shown in relation to conditionally pathogenic and pathogenic cultures of microorganisms that most often cause an infectious process in the gastrointestinal tract of children., Competing Interests: The authors declare no conflict of interest.

Background: In the course of replication of eukaryotic chromosomes, the telomere length is maintained due to activity of telomerase, the ribonucleoprotein reverse transcriptase. Abolishing telomerase function causes progressive shortening of telomeres and, ultimately, cell cycle arrest and replicative senescence. To better understand the cellular response to telomerase deficiency, we performed a transcriptomic study for the thermotolerant methylotrophic yeast Hansenula polymorpha DL-1 lacking telomerase activity., Results: Mutant strain of H. polymorpha carrying a disrupted telomerase RNA gene was produced, grown to senescence and analyzed by RNA-seq along with wild type strain. Telomere shortening induced a transcriptional response involving genes relevant to telomere structure and maintenance, DNA damage response, information processing, and some metabolic pathways. Genes involved in DNA replication and repair, response to environmental stresses and intracellular traffic were up-regulated in senescent H. polymorpha cells, while strong down-regulation was observed for genes involved in transcription and translation, as well as core histones., Conclusions: Comparison of the telomerase deletion transcription responses by Saccharomyces cerevisiae and H. polymorpha demonstrates that senescence makes different impact on the main metabolic pathways of these yeast species but induces similar changes in processes related to nucleic acids metabolism and protein synthesis. Up-regulation of a subunit of the TORC1 complex is clearly relevant for both types of yeast.

Objective: to compare non-invasive evaluation of left ventricular (LV) diastolic function (DF) by echocardiography using algorithms of the 2009 and 2016 American Society of Echocardiography (ASE)/European Association of Echocardiography (EAE, now European Association of Cardiovascular Imaging [EACVI]) Recommendations., Material and Methods: The study included 100 patients with sinus rhythm and preserved left ventricular (LV) ejection fraction (EF). In all patients LV DF was assessed using both algorithms. In accordance with the ASE/EAE 2009 algorithm pulsed-wave tissue Doppler early diastolic velocity (e velocity) at lateral and septal basal regions of mitral annulus, as well as left atrial maximum volume index were evaluated. In accordance with the ASE/EACVI 2016 algorithm for judging the presence of LV diastolic dysfunction (DD), in addition to the two above-described criteria, E/e ratio and peak velocity of tricuspid regurgitation were analyzed. In the presence of 1 and more or equal 3 criteria LVDF was classified as normal and DD, respectively. If 2 criteria were detected result was considered as indeterminate., Results: In 70% of patients in accordance with the ASE/EACVI 2016 algorithm DF was evaluated with 4 and in 100% - with 3 proposed criteria. The reason for using only 3 criteria was inadequate imaging of tricuspid regurgitation flow by continuous wave Doppler. Use of ASE/EACVI 2016 compared with the ASE/EAE 2009 algorithm in patients with normal LV EF led to a significant decrease of the number of patients with LV DD (13 vs. 27%, respectively; <0.05). The main reason for this redistribution was lowering of the cutoff value of annular e septal velocity from 8 (2009 algorithm) to 7 cm/sec (2016 algorithm). Frequency of indeterminate results with the use of 2016 algorithm was 2 times less than with the use of 2009 algorithm (15 vs. 36%, respectively; p<0.001)., Conclusion: In patients with preserved LVEF the use of ASE/EACVI 2016 algorithm led to redistribution of data of evaluation of LVDF by echocardiography towards reduction of the number of patients with LV DD and with indeterminate results.

Telomerase is a ribonucleoprotein enzyme that adds telomeric DNA fragments to the ends of chromosomes. This enzyme is the focus of substantial attention, both because its structure and mechanism of action are still poorly studied, and because of its pivotal roles in aging and cellular proliferation. The use of telomerase as a potential target for the design of new anticancer drugs is also of great interest. The catalytic protein subunit of telomerase (TERT) contains an N-terminal domain (TEN) that is essential for activity and processivity. Elucidation of the structure and dynamics of TEN in solution is important for understanding the molecular mechanism of telomerase activity and for the design of new telomerase inhibitors. To approach this problem, in this study we report the (1)H, (13)C, and (15)N chemical shift assignments of TEN from Ogataea polymorpha. Analysis of the assigned chemical shifts allowed us to identify secondary structures and protein regions potentially involved in interaction with other participants of the telomerase catalytic cycle.

Aim: Comparative typing of Leptospira spp. strain collection based on analysis of 16S RNA fragment., Materials and Methods: 2 pairs of primers were used for PCR, that jointly flank 1423b.p. sized fragment. Sequences of Leptospira spp. strain 16S rRNA, presented in the international database, were used for phylogenetic analysis., Results: A high similarity, including interspecies, of the 16S fragment in Leptospira spp. strains was shown independently of the source, serovar and serogroup. Heterogeneity of the primary matrix, spontaneous mutations of hotspots and erroneous nucleotide couplings, characteristic for 16S sequence of pathogenic Leptospira spp. strains, are discussed. Molecular-genetic characteristic of certain reference Leptospira spp. strains by 16S sequence is obtained., Conclusion: Results of the studies give evidence on expedience of introduction into clinical practice of identification of Leptospira spp. by 16S sequence directly from the clinical material, that would allow to significantly reduce identification time, dismiss complex type-specific sera and other labor-intensive methods.

Aim: Study of the ability of clinical isolates of leptospira to cause production of certain pro- and antiinflammatory cytokines in the model of human whole blood., Materials and Methods: Leptospira interrogans strain was taken for the experiment. Cytokine content was determined by a method based on xMAP technology using a standard panel, composed of 9 analytes: TNF-α, MCP-1, IL-8, IL-4, IL-6, IL-10, IL-IRa, IL- 12 (p70), IFN-γ., Results: An optimal concentration of L. interrogans was selected for stimulation of human whole blood--1 x 10(6) leptospirae/ml. For the first time in the model of human whole blood it was determined, that at early stages of incubation IFN-γ, IL-12(p70), IL-4 and IL-1Ra are more actively produced; at later stages (6 hour incubation)--IL-8 and TNF-α., Conclusion: A differential pattern of cytokine production stimulation was shown in the model of human whole blood by live and inactivated leptospirae.

Aim: Study the content of some pro- and anti-inflammatory cytokines in blood sera of leptospirosis patients in dynamics of infectious process and the role of these cytokines in the disease immunopathogenesis., Materials and Methods: The content of cytokines in blood sera was determined by a method based on xMAP technology with a standard panel consisting of 9 analytes: TNF-α, MCP-1, IL-8, IL-4, IL-6, IL-10, IL-1Ra, IL-12 (p70), IFN-γ., Results: A significantly increased level of IL-8, IL-10, TNF-α was confirmed and the increased content of MCP-1 in leptospirosis patients compared with practically healthy donors was established for the first time. Correlations between cytokines during leptospirosis were detected., Conclusion: The data obtained show that cytokines play an important role in leptospirosis immunopathogenesis.

The diagnosis of multiple sclerosis in children and adolescence should be differentiated from a group of rare white matter diseases, with fuzzy diagnostic criteria. Some of these conditions require modern diagnostic techniques and wide knowledge of the doctor. The Moscow Division for treatment of children and adolescents with multiple sclerosis is a specialized advisory structure, which has specialists with experience in the differential diagnosis of multiple sclerosis with pediatric onset. The emphasis on the clinical aspects in differential diagnosis of early onset multiple sclerosis can reduce the time for the diagnosis and help to avoid diagnostic mistakes.

Telomerase is a ribonucleoprotein, the main function of which is to synthesize telomeres, i.e. repetitive sequences which are localized at the ends of eukaryotic chromosomes. Telomerase maintains the stability of the genome in eukaryotic cells by replicating chromosomal ends. The structural and functional investigation of the telomerase complex is significantly restricted due to difficulties connected with the isolation of its main catalytic subunit in recombinant form. Herein, we describe a method developed for the isolation of the recombinant telomerase reverse transcriptase from thermotolerant yeastHansenula polymorpha. A functional test performed for the isolated protein and the RNA/DNA duplex, simulating the interaction of telomerase RNA and telomere, reveals that the isolated catalytic subunit of telomerase possesses limited reverse transcriptase activity.

The unfavorable factors of professional work of workers of locomotive brigades influence on speed of aging and adaptation possibilities of an organism. Analysis of the data obtained confirms the positive use of the peptide bioregulator Pinealon in maintenance the professional reliability of workers of locomotive brigades. Workers of locomotive brigades used preparation during two weeks (1 capsule containing 100 mkg of Pinealon 2 times a day). Pinealon application has improved parameters of biological age and indicators determining the effectiveness of adaptive reactions.

A study of professional occupational activity of the sportsmen and its effect on the risk of developing accelerated aging was conducted. Despite relatively small proportion of sport injuries and occupational diseases in the structure of morbidity (though sports are acknowledged as an occupation) it is a question of vital importance to study reasons for these injuries and diseases, and ways for their prevention and follow-up rehabilitation.

The article deals with results obtained in studies of immune system functional state among workers engaged into copper and nickel metallurgy, with data on influence of food rich in vitamins A, E and beta-carotene on workers' immune reactivity.

Tonographic studies of 18 patients with artiphakia and aphakia and rheo-ophthalmographic examinations of 36 patients with artiphakia after YAG laser discission of opaque posterior capsule of the lens have revealed significant impairment of ocular hydrodynamics, most manifest in the first hours postoperation, persisting for 24 hrs on an average. In patients, whose rheographic values were within the normal age-specific range, a marked RQ reduction 3-4 hrs postoperation was observed, still present in 24 hrs. No changes in the ocular hemodynamics were detectable in patients with initially lowered rheographic coefficient. Problems concerning the relationships between ocular hydro- and hemodynamics in reactive hypertension are discussed.