Differences in survival according to the pTERT mutation subtypes (-124C > T, -146C > T, and tandem -138_139CC > TT) have been observed. The present study aimed to describe the clinical as the histopathological and molecular cutaneous melanoma features according to the presence of the three most prevalent pTERT mutation subtypes (-124C > T, -146C > T, and tandem -138_139CC > TT). A retrospective cross-sectional study including 684 patients was designed, and a Partial Least-Squares Discriminant Analysis (PLS-DA) was performed. After the PSL-DA, it was observed that the tandem -138_139CC > TT subtype differs from the other subtypes. The model demonstrated that the -124C > T and the -138_139 CC > TT subtypes were associated with fast-growing melanomas (OR 0.5, CI 0.29-0.86, p = .012) and with Breslow >2 mm (OR 0.6, CI 0.37-0.97, p = .037), compared to the -146C > T mutation. Finally, the -124C > T appeared to be more associated with the presence of TILs (non-brisk) than the -146C > T (OR 0.6, CI 0.40-1.01, p = .05). These findings confirmed that the -124C > T and the tandem -138_139 CC > TT subtypes are both highly associated with the presence of features of aggressiveness; however, only the -124C > T was highly associated with TILs. This difference could explain the worse survival rate associated with the tandem -138_139CC > TT mutations.
- MeSH
- lidé MeSH
- melanom * genetika patologie mortalita MeSH
- mutace MeSH
- nádory kůže genetika patologie mortalita MeSH
- promotorové oblasti (genetika) * genetika MeSH
- průřezové studie MeSH
- retrospektivní studie MeSH
- telomerasa * genetika MeSH
- Check Tag
- lidé MeSH
- mužské pohlaví MeSH
- ženské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Abies guatemalensis Rehder, an endangered conifer endemic to Central American highlands, is ecologically vital in upper montane forests. It faces threats from habitat fragmentation, unsustainable logging, and illegal Christmas tree harvesting. While previous genetic studies on mature trees from eighteen populations showed high within-population diversity and limited among-population differentiation, the genetic impact of recent anthropogenic pressures on younger generations has yet to be discovered. Understanding these effects is crucial for developing effective conservation strategies for this vulnerable species. We sampled 170 young trees (< 15 years old) from seven populations across Guatemala. Seven microsatellite markers were used to analyse genetic diversity, population structure, and recent demographic history. Moderate levels of genetic diversity were observed within populations (mean Shannon diversity index = 4.97, mean Simpson's index = 0.51, mean allelic richness = 11.59, mean observed heterozygosity = 0.59). Although genetic structure broadly aligned with mountain corridors, substantial admixture patterns suggest historical connectivity across all populations. Most populations showed evidence of recent bottlenecks (p < 0.05) and inbreeding. The results suggest a potential decline in genetic diversity and increased population structuring (ΦST = 0.274, p < 0.01) over the past decades compared to the previous study on old trees. The observed genetic patterns indicate ongoing impacts of habitat fragmentation and anthropogenic pressures on A. guatemalensis. Conservation efforts should prioritise expanding effective population sizes and facilitating gene flow, particularly for isolated populations. While restoration efforts may be logistically easier within mountain ranges, genetic evidence suggests that increasing overall population connectivity could benefit this species. Management strategies should implement systematic seed collection protocols to maintain genetic diversity in future populations. These findings highlight the urgent need for conservation measures to preserve remaining genetic diversity and promote connectivity among A. guatemalensis populations.
- MeSH
- ekosystém * MeSH
- genetická variace * MeSH
- jedle * genetika MeSH
- mikrosatelitní repetice * genetika MeSH
- ohrožené druhy * MeSH
- populační genetika MeSH
- zachování přírodních zdrojů MeSH
- Publikační typ
- časopisecké články MeSH
- Geografické názvy
- Guatemala MeSH
The RNA editing enzyme adenosine deaminase acting on RNA 1 (ADAR1) is essential for correct functioning of innate immune responses. The ADAR1p110 isoform is mainly nuclear and ADAR1p150, which is interferon (IFN) inducible, is predominately cytoplasmic. Using three different methods - co-immunoprecipitation (co-IP) of endogenous ADAR1, Strep-tag co-IP and BioID with individual ADAR1 isoforms - a comprehensive interactome was generated during both homeostasis and the IFN response. Both known and novel interactors as well as editing regulators were identified. Nuclear proteins were detected as stable interactors with both ADAR1 isoforms. In contrast, BioID identified distinct protein networks for each ADAR1 isoform, with nuclear components observed with ADAR1p110 and components of cytoplasmic cellular condensates with ADAR1p150. RNase A digestion distinguished between distal and proximal interactors, as did a double-stranded RNA (dsRNA)-binding mutant of ADAR1 which demonstrated the importance of dsRNA binding for ADAR1 interactions. IFN treatment did not affect the core ADAR1 interactomes but resulted in novel interactions, the majority of which are proximal interactions retained after RNase A treatment. Short treatment with high molecular weight poly(I:C) during the IFN response resulted in dsRNA-binding-dependent changes in the proximal protein network of ADAR1p110 and association of the ADAR1p150 proximal protein network with some components of antiviral stress granules.
- MeSH
- adenosindeaminasa * metabolismus genetika MeSH
- buněčné jádro * metabolismus MeSH
- cytoplazma * metabolismus MeSH
- dvouvláknová RNA metabolismus genetika MeSH
- editace RNA MeSH
- HEK293 buňky MeSH
- HeLa buňky MeSH
- interferony metabolismus genetika MeSH
- lidé MeSH
- mapy interakcí proteinů MeSH
- poly I-C farmakologie MeSH
- protein - isoformy * metabolismus genetika MeSH
- proteiny vázající RNA * metabolismus genetika MeSH
- vazba proteinů MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
The antioxidant activity of Scorzonera parviflora Jacq. roots were assessed by measuring their ability to scavenge ABTS and DPPH radicals. Bioactivity-guided fractionation was utilized to identify the compound(s) responsible for this activity. The most active phase, ethyl acetate, was isolated using column chromatography. The resulting fractions were then purified using preparative TLC on reverse phase and semi-preparative HPLC. The structures of the pure compounds were elucidated by spectral analysis (MS and 1H, 13C, 2D-NMR). Three undescribed phenolic acid derivatives, namely parvifloric acid A (1), B (2), and C (3), and one new sesquiterpene lactone, parviflorin (4) together with seven known compounds were isolated and identified as scopolin (5), scopoletin (6), caffeic acid (7), protocatechuic acid (8), 4,5-O-dicaffeoylquinic acid (9) 3,5-O-dicaffeoylquinic acid (10), and 3,5-O-dicaffeoylquinic acid methyl ester (11). Finally, the pure compounds obtained were tested to evaluate their antioxidant capacities, using ABTS and DPPH radical scavenging potencies. The highest activity was observed with 3,5-O-dicaffeoylquinic acid (10), followed by its methyl ester.
- MeSH
- antioxidancia * farmakologie izolace a purifikace chemie MeSH
- fytonutrienty farmakologie izolace a purifikace MeSH
- hydroxybenzoáty * izolace a purifikace farmakologie chemie MeSH
- kořeny rostlin * chemie MeSH
- molekulární struktura MeSH
- Scorzonera * chemie MeSH
- seskviterpeny farmakologie izolace a purifikace chemie MeSH
- Publikační typ
- časopisecké články MeSH
Epigenetic DNA modifications are pivotal in eukaryotic gene expression, but their regulatory significance in bacteria is less understood. In Synechocystis 6803, the DNA methyltransferase M.Ssp6803II modifies the first cytosine in the GGCC motif, forming N4-methylcytosine (GGm4CC). Deletion of the sll0729 gene encoding M.Ssp6803II (∆sll0729) caused a bluish phenotype due to reduced chlorophyll levels, which was reversed by suppressor mutations. Re-sequencing of 7 suppressor clones revealed a common GGCC to GGTC mutation in the slr1790 promoter's discriminator sequence, encoding protoporphyrinogen IX oxidase, HemJ, crucial for tetrapyrrole biosynthesis. Transcriptomic and qPCR analyses indicated aberrant slr1790 expression in ∆sll0729 mutants. This aberration led to the accumulation of coproporphyrin III and protoporphyrin IX, indicative of impaired HemJ activity. To confirm the importance of DNA methylation in hemJ expression, hemJ promoter variants with varying discriminator sequences were introduced into the wild type, followed by sll0729 deletion. The sll0729 deletion segregated in strains with the GGTC discriminator motif, resulting in wild-type-like pigmentation, whereas freshly prepared ∆sll0729 mutants with the native hemJ promoter exhibited the bluish phenotype. These findings demonstrate that hemJ is tightly regulated in Synechocystis and that N4-methylcytosine is essential for proper hemJ expression. Thus, cytosine N4-methylation is a relevant epigenetic marker in Synechocystis and likely other cyanobacteria.
- MeSH
- bakteriální proteiny metabolismus genetika MeSH
- epigeneze genetická * MeSH
- metylace DNA * MeSH
- mutace MeSH
- promotorové oblasti (genetika) * MeSH
- regulace genové exprese u bakterií MeSH
- Synechocystis * genetika metabolismus MeSH
- tetrapyrroly * metabolismus biosyntéza MeSH
- Publikační typ
- časopisecké články MeSH
Satellite DNAs (satDNAs) are abundant components of eukaryotic genomes, playing pivotal roles in chromosomal organization, genome stability, and evolution. Here, we combined cytogenetic and genomic methods to characterize the satDNAs in the genomes of Leptidea butterflies. Leptidea is characterized by the presence of a high heterochromatin content, large genomes, and extensive chromosomal reshuffling as well as the occurrence of cryptic species. We show that, in contrast to other Lepidoptera, satDNAs constitute a considerable proportion of Leptidea genomes, ranging between 4.11% and 11.05%. This amplification of satDNAs, together with the hyperactivity of transposable elements, contributes to the substantial genome expansion in Leptidea. Using chromosomal mapping, we show that, particularly LepSat01-100 and LepSat03-167 satDNAs, are preferentially localized in heterochromatin exhibiting variable distribution that may have contributed to the highly diverse karyotypes within the genus. The satDNAs also exhibit W-chromosome accumulation, suggesting their involvement in sex chromosome evolution. Our results provide insights into the dynamics of satDNAs in Lepidoptera genomes and highlight their role in genome expansion and chromosomal organization, which could influence the speciation process. The high proportion of repetitive DNAs in the genomes of Leptidea underscores the complex evolutionary dynamics revealing the interplay between repetitive DNAs and genomic architecture in the genus.
G-quadruplexes (G4s) formed within RNA are emerging as promising targets for therapeutic intervention in cancer, neurodegenerative disorders and infectious diseases. Sequences containing a succession of short GG blocks, or uneven G-tract lengths unable to form three-tetrad G4s (GG motifs), are overwhelmingly more frequent than canonical motifs involving multiple GGG blocks. We recently showed that DNA is not able to form stable two-tetrad intramolecular parallel G4s. Whether RNA GG motifs can form intramolecular G4s under physiological conditions and play regulatory roles remains a burning question. In this study, we performed a systematic analysis and experimental evaluation of a number of biologically important RNA regions involving RNA GG motifs. We show that most of these motifs do not form stable intramolecular G4s but need to dimerize to form stable G4 structures. The strong tendency of RNA GG motif G4s to associate may participate in RNA-based aggregation under conditions of cellular stress.
- MeSH
- dimerizace MeSH
- G-kvadruplexy * MeSH
- genetická transkripce MeSH
- lidé MeSH
- nukleotidové motivy * MeSH
- RNA * chemie metabolismus genetika MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
DNA double-strand breaks (DSBs) represent a lethal form of DNA damage that can trigger cell death or initiate oncogenesis. The activity of RNA polymerase II (RNAPII) at the break site is required for efficient DSB repair. However, the regulatory mechanisms governing the transcription cycle at DSBs are not well understood. Here, we show that Integrator complex subunit 6 (INTS6) associates with the heterotrimeric sensor of ssDNA (SOSS1) complex (comprising INTS3, INIP and hSSB1) to form the tetrameric SOSS1 complex. INTS6 binds to DNA:RNA hybrids and promotes Protein Phosphatase 2A (PP2A) recruitment to DSBs, facilitating the dephosphorylation of RNAPII. Furthermore, INTS6 prevents the accumulation of damage-associated RNA transcripts (DARTs) and the stabilization of DNA:RNA hybrids at DSB sites. INTS6 interacts with and promotes the recruitment of senataxin (SETX) to DSBs, facilitating the resolution of DNA:RNA hybrids/R-loops. Our results underscore the significance of the tetrameric SOSS1 complex in the autoregulation of DNA:RNA hybrids and efficient DNA repair.
- MeSH
- DNA vazebné proteiny metabolismus MeSH
- DNA-helikasy metabolismus genetika MeSH
- DNA * metabolismus chemie MeSH
- dvouřetězcové zlomy DNA * MeSH
- fosforylace MeSH
- homeostáza genetika MeSH
- lidé MeSH
- oprava DNA * MeSH
- proteinfosfatasa 2 metabolismus genetika MeSH
- R-smyčka MeSH
- RNA-helikasy metabolismus genetika MeSH
- RNA-polymerasa II * metabolismus MeSH
- RNA * metabolismus genetika chemie MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
Pochopení vztahu mezi senzomotorickými proměnnými a exerkiny, které ovlivňují funkci mozku a kognici, nám umožňuje hlouběji porozumět biologickému procesu stárnutí. Hlavním cílem této studie bylo zjistit, jak silně jsou mozkový neurotrofický faktor (brain-derived neurotrophic factor, BDNF), irisin, svalová hmota a svalová síla asociovány s výsledky testů vybraných kognitivních funkcí u starších žen a jak dobře je predikují. Padesát sedm starších žen (průměrný věk 70,4 ± 4,1 roku) absolvovalo baterii neuropsychologických testů, měření izometrické dynamometrie a bioelektrické impedance. Hladiny v krevním séru sledovaných exerkinů byly stanoveny enzymatickým imunosorbentním testem (ELISA). Pro testování predikcí byly využity hierarchické vícenásobné regresní modely. Odhadli jsme, že rozptyl 46,1 % v krátkodobé paměti byl zapříčiněn hladinami BDNF v séru, přičemž druhým statisticky významným prediktorem byl věk (beta = –0,22; p = 0,030). Síla dolních končetin (lower limb strength, LLS) prokázala významnou prediktivní sílu jak u paměti – bezprostřední vybavení (beta = 0,39; p = 0,004), tak u paměti – oddálené vybavení (beta = 0,45; p = 0,001). Hladiny BDNF v séru byly významným prediktorem u oddáleného vybavení (beta = 0,29; p = 0,048). Přidání hladin BDNF do modelu prokázalo významné zvýšení jeho prediktivní síly o přibližně 5,6 % (p = 0,048) u paměti – oddálené vybavení. Index kosterní svalové hmoty (skeletal muscle index, SMI) a úroveň vzdělání byly významnými prediktory mentální flexibility. Byla zjištěna silná pozitivní asociace mezi hladinami BDNF, irisinem, svalovou silou a kognitivní funkcí, přičemž irisin a svalová síla jsou silnými prediktory hladin BDNF u starších žen. Studie byla realizována s podporou grantu Univerzity Karlovy – PRIMUS/19/HUM/012, Specifického vysokoškolského výzkumu SVV 260599, projektu COOPERATIO a Grantové agentury UK číslo grantu 268321. Korespondenční adresa: PhDr. Veronika Holá Katedra gymnastiky a úpolových sportů FTVS UK José Martího 269/31 162 52 Praha 6-Veleslavín e-mail: veronika.hola@ftvs.cuni.cz
Understanding the relationship between sensorimotor variables and exerkines related to brain function and cognition may help better understand biological ageing. The main aim of this study was to determine how strongly brain-derived neurotrophic factor (BDNF), irisin, muscle mass and muscle strength are associated and predict scores on selected cognitive domain tests in older women. Fifty seven older women (mean age 70.4 ± 4.1 years) underwent a battery of cognitive and psychological tests and measurements of isometric dynamometry and bioelectrical impedance. Serum exerkines levels were measured by enzyme-linked immunosorbent assay (ELISA). Hierarchical multiple regression models were used to test the predictions. We estimated that 46.1% of the variance in short-term memory was accounted for by serum BDNF levels, with age being the second statistically significant predictor (Beta = -0.22; p = 0.030). Lower limb strength (LLS) showed significant predictive power in both immediate (Beta = 0.39; p = 0.004) and delayed memory (Beta = 0.45; p = 0.001), serum BDNF levels were a significant predictor in delayed memory (Beta = 0.29; p = 0.048). Adding serum BDNF levels to the model showed a significant increase in predictive power of approximately 5.6% (p = 0.048) in delayed memory. Skeletal muscle index (SMI) and education level were significant predictors of mental flexibility. A strong positive association between BDNF levels, irisin, muscle strength, and cognitive function was found, with irisin and muscle strength being strong predictors of BDNF levels in older women.
- Klíčová slova
- irisin,
- MeSH
- fibronektinová doména typu III fyziologie MeSH
- kognice fyziologie MeSH
- kognitivní stárnutí * fyziologie MeSH
- lidé MeSH
- mozkový neurotrofický faktor krev MeSH
- neuropsychologické testy * statistika a číselné údaje MeSH
- paměť fyziologie MeSH
- prognóza MeSH
- průřezové studie MeSH
- regresní analýza MeSH
- senioři MeSH
- svalová atrofie etiologie MeSH
- svalová síla fyziologie MeSH
- Check Tag
- lidé MeSH
- senioři MeSH
- ženské pohlaví MeSH
- Publikační typ
- práce podpořená grantem MeSH
High-risk human papillomaviruses (HPVs) cause various cancers. While type-specific prophylactic vaccines are available, additional anti-viral strategies are highly desirable. Initial HPV cell entry involves receptor-switching induced by structural capsid modifications. These modifications are initiated by interactions with cellular heparan sulphates (HS), however, their molecular nature and functional consequences remain elusive. Combining virological assays with hydrogen/deuterium exchange mass spectrometry, and atomic force microscopy, we investigate the effect of capsid-HS binding and structural activation. We show how HS-induced structural activation requires a minimal HS-chain length and simultaneous engagement of several binding sites by a single HS molecule. This engagement introduces a pincer-like force that stabilizes the capsid in a conformation with extended capsomer linkers. It results in capsid enlargement and softening, thereby likely facilitating L1 proteolytic cleavage and subsequent L2-externalization, as needed for cell entry. Our data supports the further devising of prophylactic strategies against HPV infections.
- MeSH
- heparitinsulfát * metabolismus chemie MeSH
- infekce papilomavirem virologie MeSH
- internalizace viru * MeSH
- kapsida * metabolismus chemie MeSH
- lidé MeSH
- lidské papilomaviry MeSH
- lidský papilomavirus 16 metabolismus fyziologie MeSH
- mikroskopie atomárních sil * MeSH
- Papillomaviridae fyziologie MeSH
- polysacharidy metabolismus chemie MeSH
- vazba proteinů MeSH
- vazebná místa MeSH
- virové plášťové proteiny * metabolismus chemie MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
