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1.
J Biol Chem ; 300(6): 107288, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38636662

RESUMO

HCN channels are important for regulating heart rhythm and nerve activity and have been studied as potential drug targets for treating depression, arrhythmia, nerve pain, and epilepsy. Despite possessing unique pharmacological properties, HCN channels share common characteristics in that they are activated by hyperpolarization and modulated by cAMP and other membrane lipids. However, the mechanisms of how these ligands bind and modulate HCN channels are unclear. In this study, we solved structures of full-length human HCN3 using cryo-EM and captured two different states, including a state without any ligand bound and a state with cAMP bound. Our structures reveal the novel binding sites for cholesteryl hemisuccinate in apo state and show how cholesteryl hemisuccinate and cAMP binding cause conformational changes in different states. These findings explain how these small modulators are sensed in mammals at the molecular level. The results of our study could help to design more potent and specific compounds to influence HCN channel activity and offer new therapeutic possibilities for diseases that lack effective treatment.


Assuntos
Microscopia Crioeletrônica , AMP Cíclico , Canais Disparados por Nucleotídeos Cíclicos Ativados por Hiperpolarização , Humanos , Sítios de Ligação , AMP Cíclico/metabolismo , Células HEK293 , Canais Disparados por Nucleotídeos Cíclicos Ativados por Hiperpolarização/metabolismo , Canais Disparados por Nucleotídeos Cíclicos Ativados por Hiperpolarização/química , Canais Disparados por Nucleotídeos Cíclicos Ativados por Hiperpolarização/genética , Conformação Proteica
2.
Plant Mol Biol ; 114(4): 85, 2024 Jul 12.
Artigo em Inglês | MEDLINE | ID: mdl-38995464

RESUMO

Phenylpropanoids, a class of specialized metabolites, play crucial roles in plant growth and stress adaptation and include diverse phenolic compounds such as flavonoids. Phenylalanine ammonia-lyase (PAL) and chalcone synthase (CHS) are essential enzymes functioning at the entry points of general phenylpropanoid biosynthesis and flavonoid biosynthesis, respectively. In Arabidopsis, PAL and CHS are turned over through ubiquitination-dependent proteasomal degradation. Specific kelch domain-containing F-Box (KFB) proteins as components of ubiquitin E3 ligase directly interact with PAL or CHS, leading to polyubiquitinated PAL and CHS, which in turn influences phenylpropanoid and flavonoid production. Although phenylpropanoids are vital for tomato nutritional value and stress responses, the post-translational regulation of PAL and CHS in tomato remains unknown. We identified 31 putative KFB-encoding genes in the tomato genome. Our homology analysis and phylogenetic study predicted four PAL-interacting SlKFBs, while SlKFB18 was identified as the sole candidate for the CHS-interacting KFB. Consistent with their homolog function, the predicted four PAL-interacting SlKFBs function in PAL degradation. Surprisingly, SlKFB18 did not interact with tomato CHS and the overexpression or knocking out of SlKFB18 did not affect phenylpropanoid contents in tomato transgenic lines, suggesting its irreverence with flavonoid metabolism. Our study successfully discovered the post-translational regulatory machinery of PALs in tomato while highlighting the limitation of relying solely on a homology-based approach to predict interacting partners of F-box proteins.


Assuntos
Aciltransferases , Proteínas F-Box , Regulação da Expressão Gênica de Plantas , Fenilalanina Amônia-Liase , Filogenia , Proteínas de Plantas , Solanum lycopersicum , Solanum lycopersicum/genética , Solanum lycopersicum/metabolismo , Proteínas F-Box/metabolismo , Proteínas F-Box/genética , Proteínas de Plantas/metabolismo , Proteínas de Plantas/genética , Fenilalanina Amônia-Liase/metabolismo , Fenilalanina Amônia-Liase/genética , Aciltransferases/metabolismo , Aciltransferases/genética , Flavonoides/metabolismo , Flavonoides/biossíntese , Plantas Geneticamente Modificadas , Propanóis/metabolismo
3.
J Biomol NMR ; 78(1): 31-37, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38072902

RESUMO

For the A2A adenosine receptor (A2AAR), a class A G-protein-coupled receptor (GPCR), reconstituted in n-dodecyl-ß-D-maltoside (DDM)/|||||cholesteryl hemisuccinate (CHS) mixed micelles, previous 19F-NMR studies revealed the presence of multiple simultaneously populated conformational states. Here, we study the influence of a different detergent, lauryl maltose neopentyl glycol (LMNG) in mixed micelles with CHS, and of lipid bilayer nanodiscs on these conformational equilibria. The populations of locally different substates are pronouncedly different in DDM/|||||CHS and LMNG/|||||CHS micelles, whereas the A2AAR conformational manifold in LMNG/|||||CHS micelles is closely similar to that in the lipid bilayer nanodiscs. Considering that nanodiscs represent a closer match of the natural lipid bilayer membrane, these observations support that LMNG/|||||CHS micelles are a good choice for reconstitution trials of class A GPCRs for NMR studies in solution.


Assuntos
Detergentes , Bicamadas Lipídicas , Bicamadas Lipídicas/química , Detergentes/química , Micelas , Ressonância Magnética Nuclear Biomolecular , Receptores Purinérgicos P1 , Receptor A2A de Adenosina/química
4.
BMC Plant Biol ; 24(1): 18, 2024 Jan 02.
Artigo em Inglês | MEDLINE | ID: mdl-38166751

RESUMO

Camellia reticulata Lindl., also known as Yunnan Camellia, is an important ornamental plant in China, especially for its large and stunning flowers. A comprehensive understanding of their coloration mechanisms can aid breeders in developing new cultivars and improving their ornamental value; however, it is still unclear in Yunnan Camellia, especially in mixed-color flowers. In this study, we conducted metabolic and transcriptomic comparison analyses to investigate the coloration differences in three Yunnan Camellia cultivars: C. reticulata 'Shizitou' (SZT), C. reticulata 'Damanao' (MN), and C. reticulata 'Tongzimian' (TZM). Our results revealed that the initial flowering stage may play a critical role in the color change of MN. Metabolome analysis demonstrated that cyanidin was the primary anthocyanin in SZT and MN's red region, while its content was low in TZM and MN's white region. According to the transcriptome analysis, the anthocyanins biosynthesis pathway was reconstructed in Yunnan Camellia, and the low expression of CHS was detected in TZM and MN's white region, while ANR maintained a high expression level, which may lead to the low content of cyanidin in them. Transcription factors MYBs, bHLH, and bZIP may play a key role in regulating anthocyanin-structural genes. The co-expression analysis showed that the meristem tissue may play a crucial role in the formation of the mixed white-red color in MN. Our study enriched the genetic basis of flower coloration differences in Yunnan Camellia which will be a valuable genomic resource to understanding the biology of coloration formation and for breeding the Camellia cultivars.


Assuntos
Camellia , Camellia/genética , Camellia/metabolismo , Antocianinas/metabolismo , China , Melhoramento Vegetal , Perfilação da Expressão Gênica , Flores/metabolismo , Regulação da Expressão Gênica de Plantas , Transcriptoma , Pigmentação/genética
5.
Blood Cells Mol Dis ; 109: 102874, 2024 Jul 11.
Artigo em Inglês | MEDLINE | ID: mdl-39032214

RESUMO

Chediak-Higashi syndrome (CHS) is a rare autosomal recessive genetic disorder characterized by severe immunodeficiency, albinism and coagulation deficiency. Mostly diagnosed in early childhood, this devastating condition is associated with lysosomal abnormalities attributed to the absence or impaired function of lysosomal trafficking regulator caused by mutations in the CHS1/LYST gene. In current study, we report a case of late-onset CHS caused by two novel compound heterozygous CHS1/LYST mutations: c.8407C > T, leading to early termination of translation at residue Gln2803 (p. Gln2803Ter), and a small deletion c. 4020_4031del, resulting in an in-frame deletion of three amino acid residues (p. Asp1343_Val1346del). Both variants retain a large part of the CHS/LYST protein, particularly p. Asp1343_Val1346del, which preserves critical functional BEACH and WD40 domains in the C terminal, potentially maintaining residual activity and alleviating patient symptoms. The timeline of SARS-CoV-2 infection and rapid symptom progression suggests that the viral infection may have trigger the accelerated phase development leading to a poor prognosis.

6.
Plant Cell Environ ; 47(3): 765-781, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38031484

RESUMO

Plants are confronted with various environmental stresses and develop sophisticated adaptive mechanisms. Our previous work demonstrated that the crosstalk of flg22 and ultraviolet (UV)-B-induced signalling cascades reprograms the expression of flavonol pathway genes (FPGs), benefiting plant defence responses. Although several transcription factors have been identified to be involved in this crosstalk, the underlying mechanism is largely unclear. Here, we analyzed microRNAs (miRNAs) and identified 126, 129 and 113 miRNAs with altered abundances compared to untreated control in flg22-, UV-B- and flg22/UV-B-treated seedlings, respectively. Two distinct modules were identified: The first consists of 10 miRNAs repressed by UV-B but up-regulated by flg22, and the second with five miRNAs repressed by flg22 but up-regulated by UV-B. In Arabidopsis, the knockdown of miR858a, a representative of module I, increased the abundance of CHS (a marker gene for FPGs), whereas its overexpression reduced CHS. Conversely, knockout of miR164b from module II decreased CHS and its overexpression increased CHS transcript levels. These data suggest a decisive role of miRNAs in the crosstalk. In the next, we described the interaction between miR858a and its target MYB111 (a positive regulator of FPGs) from module I in detail. We showed that MYB111 was profoundly post-transcriptionally regulated by miR858a during the crosstalk, whose expression was specifically but antagonistically controlled by UVR8- and FLS2-mediated signallings. Moreover, transcriptional monitoring using the GUS reporter gene demonstrates that miRNA-mediated posttranscriptional regulation is the main driving force in reprogramming the expression of FPGs and regulates plant adaptation to multiple concurrent environmental stresses.


Assuntos
Proteínas de Arabidopsis , Arabidopsis , MicroRNAs , Arabidopsis/genética , Arabidopsis/metabolismo , Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , MicroRNAs/genética , MicroRNAs/metabolismo , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo , Flavonóis/metabolismo , Estresse Fisiológico/genética , Regulação da Expressão Gênica de Plantas , Raios Ultravioleta
7.
Nanotechnology ; 35(14)2024 Jan 17.
Artigo em Inglês | MEDLINE | ID: mdl-37992401

RESUMO

Creating a scaffold for bone tissue engineering that is bioactive and capable of acting as a local-dual delivery system, releasing bioactive molecules and regulating the bone remodeling process to achieve balanced bone resorption and formation, is a significant challenge. The objective of this research is to create a composite scaffold using chitosan/gelatin (CHS/Gel) and the calcium (Ca)-alendronate (ALN) metal-organic frameworks (MOFs). The scaffold will act as a dual-delivery system, releasing Ca ions and ALN to regulate bone formation. Ca-ALN MOF nanoparticles (NPs) were prepared in mild conditions and studied by FTIR, XRD, FESEM, and TGA. Ca-ALN NPs-loaded CHS/Gel scaffolds were opportunely fabricated through freeze-drying approach. Physicochemical features of the scaffolds after incorporating NPs equated by CHS/Gel scaffold changed, therefore, the attendance of NPs caused a decreasing porosity, decreased swelling, and low rate of degradation. The release profile results showed that the NPs-loaded CHS/Gel scaffolds were able to simultaneously release ALN and Ca ions due to the decomposition of NPs. Additionally, the loading of NPs in the CHS/Gel scaffold led to an increment in alkaline phosphatase (ALP) activity and the quantity of deposited Ca along with osteogenesis gene markers. These findings suggest that the NPs-loaded CHS/Gel scaffold has the potential to enhance the differentiation of human adipose tissue-derived mesenchymal stem cells, making it a promising approach for bone repair.


Assuntos
Quitosana , Estruturas Metalorgânicas , Humanos , Engenharia Tecidual/métodos , Gelatina/química , Quitosana/química , Cálcio , Alicerces Teciduais/química , Osteogênese , Alendronato , Íons , Porosidade
8.
J Urban Health ; 101(2): 308-317, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38575725

RESUMO

Common mental disorders such as depression and anxiety are prevalent globally, and rates are especially high in New York City (NYC) since the COVID-19 pandemic. Neighborhood social and physical environments have been found to influence mental health. We investigated the impact of neighborhood social cohesion and neighborhood rodent sightings (as an indicator of neighborhood cleanliness) on nonspecific serious psychological distress (NSPD) status using 2020 NYC Community Health Survey data from 8781 NYC residents. Multivariable logistic regression was used to evaluate the relationships among social cohesion, rodent sightings, and NSPD adjusted for confounders and complex sampling and weighted to the NYC population. Effect measure modification of rodent sightings on the effect of social cohesion on NSPD was evaluated on the multiplicative scale by adding the interaction term to the multivariable model and, if significant, stratifying on the effect modifier, and on the additive scale using the relative excess risk due to interaction (RERI). Social cohesion was found to decrease the odds of NSPD, and rodent sightings were found to increase the odds of NSPD. We found significant evidence of effect measure modification on the multiplicative scale. In the stratified models, there was a protective effect of social cohesion against NSPD among those not reporting rodent sightings, but no effect among those reporting rodent sightings. Our findings suggest that both neighborhood social cohesion and rodent sightings impact the mental health of New Yorkers and that rodent infestations may diminish the benefit of neighborhood social cohesion.


Assuntos
COVID-19 , Saúde Mental , Características de Residência , Cidade de Nova Iorque/epidemiologia , COVID-19/psicologia , COVID-19/epidemiologia , Humanos , Masculino , Feminino , Adulto , Animais , Pessoa de Meia-Idade , Características de Residência/estatística & dados numéricos , Roedores , SARS-CoV-2 , Características da Vizinhança , Adulto Jovem , Idoso , Adolescente , Meio Social , Inquéritos Epidemiológicos , Pandemias
9.
Mikrochim Acta ; 191(4): 192, 2024 03 12.
Artigo em Inglês | MEDLINE | ID: mdl-38467931

RESUMO

FeOx-TiO2@Carbon hybrid structure materials (FeOx-TiO2@CHs) with high peroxidase (POD)-like activity have been prepared by one-pot hydrothermal method. Based on the excellent POD activity of FeOx-TiO2@CHs, one pot colorimetric detection for glucose was constructed by using TMB as substrate with the synergistic reaction of glucose oxidase; the linear range and the limit of detection (LOD) are 25 ~ 1000 and 1.77 µM, respectively. Using this method, the glucose in serum real samples was detected with satisfactory results, and the results are consistent with that of the glucometer method in the hospital. The recovery in diabetic and artificial urine samples was 95.71 ~ 104.67% and 99.01 ~ 103.16%, respectively. The mechanism of the catalytic colorimetric reaction was also investigated by multiple measurements, and the results indicated that superoxide anions (O2•-) between FeOx-TiO2@CHs and substrate play a main role, but a small quantity of hydroxyl radical •OH and singlet oxygen 1O2 is also generated simultaneously. The one-pot reaction method is simple and fast; the detection process only requires a simple mixing, which is suitable for application in special environment.


Assuntos
Glucose , Peroxidase , Peroxidase/química , Carbono/química , Colorimetria/métodos , Peróxido de Hidrogênio/química , Peroxidases/química , Corantes
10.
New Phytol ; 238(3): 1163-1181, 2023 05.
Artigo em Inglês | MEDLINE | ID: mdl-36772852

RESUMO

In eukaryotes, the majority of newly synthesized integral membrane proteins are inserted into the endoplasmic reticulum (ER) membrane before transferred to their functional sites. The conserved ER membrane complex (EMC) takes part in the insertion process for tail-anchored membrane proteins. However, the function of EMC in phytopathogenic fungi has not been characterized. Here, we report the identification and functional characterization of two EMC subunits MoEmc5 and MoEmc2 in Magnaporthe oryzae. The knockout mutants ΔMoemc5 and ΔMoemc2 exhibit substantial defect in autophagy, pathogenicity, cell wall integrity, and magnesium ion sensitivity. We demonstrate that the autophagy process was severely impaired in the ΔMoemc5 and ΔMoemc2 mutants because of the low-protein steady-state level of Atg9, the sole membrane-associated autophagy protein. Furthermore, the protein level of membrane proteins Chs4, Fks1, and MoMnr2 is also significantly reduced in the ΔMoemc5 and ΔMoemc2 strains, leading to their supersensitivity to Calcofluor white, Congo red, and magnesium. In addition, MoEmc5, but not MoEmc2, acts as a magnesium transporter independent of its EMC function. Magnaporthe oryzae EMC regulates the biogenesis of membrane proteins for autophagy and virulence; therefore, EMC subunits could be potential targets for fungicide design in the future.


Assuntos
Magnaporthe , Oryza , Virulência , Proteínas Fúngicas/metabolismo , Proteínas de Membrana/genética , Proteínas de Membrana/metabolismo , Magnésio/metabolismo , Retículo Endoplasmático/metabolismo , Oryza/metabolismo , Doenças das Plantas/microbiologia
11.
Gastroenterology ; 159(1): 62-80, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-32333910

RESUMO

Medical and recreational cannabis use has increased dramatically over the last decade, resulting from mainstream cultural acceptance and legalization in several countries worldwide. Cannabis and its derivatives affect many gastrointestinal processes via the endocannabinoid system (ECS). The ECS influences gastrointestinal homeostasis through anti-inflammatory, anti-nociceptive, and anti-secretory effects. Some gastrointestinal disorders might therefore be treated with cannabinoids. Despite numerous studies in cell lines and animals, few human studies have evaluated the therapeutic effects of cannabinoids. Cannabis' schedule 1 drug status has limited its availability in research; cannabis has been legalized only recently, in some states, for medicinal and/or recreational use. Cannabinoids can alleviate chemotherapy-induced nausea and emesis and chronic pain. Studies have demonstrated the important roles of the ECS in metabolism, obesity, and nonalcoholic fatty liver disease and the anti-inflammatory effects of cannabis have been investigated in patients with inflammatory bowel diseases. Despite its potential benefits, undesired or even detrimental effects of cannabis can limit its use. Side effects such as cannabinoid hyperemesis syndrome affect some users. We review the ECS and the effects of cannabis and its derivatives on gastrointestinal and hepatic function in health and disease.


Assuntos
Canabinoides/uso terapêutico , Endocanabinoides/metabolismo , Maconha Medicinal/uso terapêutico , Receptores de Canabinoides/metabolismo , Animais , Antineoplásicos/efeitos adversos , Canabinoides/farmacologia , Dor Crônica/tratamento farmacológico , Modelos Animais de Doenças , Motilidade Gastrointestinal/efeitos dos fármacos , Motilidade Gastrointestinal/fisiologia , Trato Gastrointestinal/efeitos dos fármacos , Trato Gastrointestinal/fisiologia , Humanos , Fígado/efeitos dos fármacos , Fígado/metabolismo , Maconha Medicinal/farmacologia , Náusea/induzido quimicamente , Náusea/tratamento farmacológico , Náusea/fisiopatologia , Hepatopatia Gordurosa não Alcoólica/tratamento farmacológico , Obesidade/tratamento farmacológico , Obesidade/fisiopatologia , Vômito/induzido quimicamente , Vômito/tratamento farmacológico , Vômito/fisiopatologia
12.
Physiol Plant ; 172(1): 64-76, 2021 May.
Artigo em Inglês | MEDLINE | ID: mdl-33247451

RESUMO

Chalcone synthase (CHS) is the key enzyme in the flavonoid biosynthetic pathway and has been studied in many plants, but the function of the CHS gene has not been well characterized in Paeonia ostii. In this study, we obtained a CHS homolog gene from P. ostii, which possessed the putative conserved amino acids of chalcone synthase by multiple alignment analysis and demonstrated the highest expression in developing seeds. In vitro assays of the recombinant PoCHS protein confirmed enzymatic activity using malonyl-CoA and 4-coumaroyl-CoA as substrates, and the optimal pH and reaction temperature were 7.5 and 40 °C, respectively. Furthermore, ectopic over-expression of PoCHS in Arabidopsis up-regulated the expression levels of genes involved in seed development (ABI), glycolysis (PKp2, PDH-E1a, and SUS2/3), and especially fatty acid biosynthesis (BCCP2, CAC2, CDS2, FatA, and FAD3). This resulted in an increased unsaturated fatty acid content, especially α-linolenic acid, in transgenic Arabidopsis seeds. In this study, we examined the functions of CHS homolog of P. ostii and demonstrated its new function in seed fatty acid biosynthesis.


Assuntos
Arabidopsis , Paeonia , Arabidopsis/genética , Vias Biossintéticas/genética , Ácidos Graxos , Paeonia/genética , Sementes/genética
13.
Adv Exp Med Biol ; 1269: 63-67, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33966196

RESUMO

Cerebral hyperperfusion syndrome (CHS) is a rare but fatal perioperative complication after surgical correction of carotid stenosis. Despite numerous treatment options for preventing CHS, it does occur in some patients. We developed the outlet gate technique (OGT), in which the embolic balloon was deflated gradually in accordance with the ratio of oxygen saturation measured by a brain oximeter of the ipsilateral brain region to that in the contralateral region. Between June 2017 and May 2018, 39 patients with carotid stenosis underwent endovascular carotid revascularization procedures; of these, 20 underwent the procedure with the OGT. CBO was measured five times in those 20 patients: before the procedure, with the embolic protection device (EPD) on, with the EPD off, during the procedure, and after the procedure. Preventive treatment options were used more frequently in these patients, and although their surgical status seemed more complicated, perioperative complications were not increased. There were almost significant differences between CBO values except between those during and after the procedure with the OGT. This showed that the OGT allowed for stabilization of the CBO and thus has the potential to prevent CHS.


Assuntos
Estenose das Carótidas , Espectroscopia de Luz Próxima ao Infravermelho , Artérias Carótidas , Circulação Cerebrovascular , Humanos , Stents
14.
Genomics ; 112(2): 1781-1794, 2020 03.
Artigo em Inglês | MEDLINE | ID: mdl-31678153

RESUMO

Dendrobium officinale is a kind of crop and precious herbal that is widely distributed in China. We applied transcriptomics to investigate the flavonoids and their biosynthesis-related genes from different tissues. Total flavonoid was determined in three different tissues. In this study, nine cDNA libraries were generated from Dendrobium officinale. A total of 530 million (70.73%) of the high-quality reads were successfully mapped to the reference genome of Dendrobium officinale and nine libraries were combined and assembled into 24,927 non-redundant genes. We mapped all of these genes to reference pathways in the KEGG database to identify polysaccharide and secondary metabolites pathways in which the genes may be involved. We outlined the biosynthetic pathway of flavonoids and identified putative genes, which provide understanding of the biosynthesis and regulation of Dendrobium officinale flavonoids at the molecular level. We identified five CHS genes from Dendrobium officinale and characterized the CHS gene family. The flavonoid-related key enzyme genes were identified, and their expression patterns in different tissues were further analyzed using quantitative real-time PCR. These data on flavonoid genes obtained in this work will be useful in understanding the molecular mechanisms of different tissues in Dendrobium officinale.


Assuntos
Dendrobium/genética , Flavonoides/biossíntese , Transcriptoma , Aciltransferases/genética , Aciltransferases/metabolismo , Flavonoides/genética , Flores/genética , Flores/metabolismo , Genes de Plantas , Folhas de Planta/genética , Folhas de Planta/metabolismo , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Raízes de Plantas/genética , Raízes de Plantas/metabolismo
15.
Int J Mol Sci ; 22(4)2021 Feb 19.
Artigo em Inglês | MEDLINE | ID: mdl-33669810

RESUMO

Repetitive DNA in humans is still widely considered to be meaningless, and variations within this part of the genome are generally considered to be harmless to the carrier. In contrast, for euchromatic variation, one becomes more careful in classifying inter-individual differences as meaningless and rather tends to see them as possible influencers of the so-called 'genetic background', being able to at least potentially influence disease susceptibilities. Here, the known 'bad boys' among repetitive DNAs are reviewed. Variable numbers of tandem repeats (VNTRs = micro- and minisatellites), small-scale repetitive elements (SSREs) and even chromosomal heteromorphisms (CHs) may therefore have direct or indirect influences on human diseases and susceptibilities. Summarizing this specific aspect here for the first time should contribute to stimulating more research on human repetitive DNA. It should also become clear that these kinds of studies must be done at all available levels of resolution, i.e., from the base pair to chromosomal level and, importantly, the epigenetic level, as well.


Assuntos
Sequências Repetitivas de Ácido Nucleico/genética , Cromossomos Humanos/genética , DNA Satélite/genética , Genoma Humano , Humanos , Repetições de Microssatélites/genética , Repetições Minissatélites/genética
16.
Traffic ; 19(4): 285-295, 2018 04.
Artigo em Inglês | MEDLINE | ID: mdl-29405545

RESUMO

The polytopic yeast protein Chs3 (chitin synthase III) relies on a dedicated membrane-localized chaperone, Chs7, for its folding and expression at the cell surface. In the absence of Chs7, Chs3 forms high molecular weight aggregates and is retained in the endoplasmic reticulum (ER). Chs7 was reported to be an ER resident protein, but its role in Chs3 folding and transport was not well characterized. Here, we show that Chs7 itself exits the ER and localizes with Chs3 at the bud neck and intracellular compartments. We identified mutations in the Chs7 C-terminal cytosolic domain that do not affect its chaperone function, but cause it to dissociate from Chs3 at a post-ER transport step. Mutations that prevent the continued association of Chs7 with Chs3 do not block delivery of Chs3 to the cell surface, but dramatically reduce its catalytic activity. This suggests that Chs7 engages in functionally distinct interactions with Chs3 to first promote its folding and ER exit, and subsequently to regulate its activity at the plasma membrane.


Assuntos
Membrana Celular/metabolismo , Quitina Sintase/metabolismo , Proteínas de Membrana/metabolismo , Chaperonas Moleculares/metabolismo , Proteínas de Saccharomyces cerevisiae/metabolismo , Saccharomyces cerevisiae/metabolismo , Quitina Sintase/genética , Retículo Endoplasmático/metabolismo , Proteínas de Membrana/genética , Chaperonas Moleculares/genética , Proteínas de Saccharomyces cerevisiae/genética
17.
BMC Microbiol ; 20(1): 51, 2020 03 05.
Artigo em Inglês | MEDLINE | ID: mdl-32138640

RESUMO

BACKGROUND: Previous phylogenetic analyses of species within the genus Golovinomyces (Ascomycota, Erysiphales), based on ITS and 28S rDNA sequence data, revealed a co-evolutionary relationship between powdery mildew species and hosts of certain tribes of the plant family Asteraceae. Golovinomyces growing on host plants belonging to the Heliantheae formed a single lineage, comprised of a morphologically differentiated complex of species, which included G. ambrosiae, G. circumfusus, and G. spadiceus. However, the lineage also encompassed sequences retrieved from Golovinomyces specimens on other Asteraceae tribes as well as other plant families, suggesting the involvement of a plurivorous species. A multilocus phylogenetic examination of this complex, using ITS, 28S, IGS (intergenic spacer), TUB2 (beta-tubulin), and CHS1 (chitin synthase I) sequence data was carried out to clarify the discrepancies between ITS and 28S rDNA sequence data and morphological differences. Furthermore, the circumscription of species and their host ranges were emended. RESULTS: The phylogenetic and morphological analyses conducted in this study revealed three distinct species named, viz., (1) G. ambrosiae emend. (including G. spadiceus), a plurivorous species that occurs on a multitude of hosts including, Ambrosia spp., multiple species of the Heliantheae and plant species of other tribes of Asteraceae including the Asian species of Eupatorium; (2) G. latisporus comb. nov. (≡ Oidium latisporum), the closely related, but morphologically distinct species confined to hosts of the Heliantheae genera Helianthus, Zinnia, and most likely Rudbeckia; and (3) G. circumfusus confined to Eupatorium cannabinum in Europe. CONCLUSIONS: The present results provide strong evidence that the combination of multi-locus phylogeny and morphological analysis is an effective way to identify species in the genus Golovinomyces.


Assuntos
DNA Fúngico/genética , Erysiphe/classificação , Tipagem de Sequências Multilocus/métodos , Código de Barras de DNA Taxonômico , Erysiphe/genética , Evolução Molecular , Técnicas de Tipagem Micológica , Filogenia , Análise de Sequência de DNA
18.
Extremophiles ; 24(1): 135-145, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31655895

RESUMO

In the present study, cyanobacterium isolate CHS1 isolated from Hopar glacier, Pakistan, was analyzed for the first time for cell membrane fatty acids and production of pigments. Sequencing of the 16-23S intergenetic region confirmed identification of the isolate CHS1 as Nodularia spumigena. All chlorophyll and carotenoid pigments were quantified using high-performance liquid chromatography and experiments to test tolerance against a range of physico-chemical conditions were conducted. Likewise, the fatty acid profile of the cell membrane CHS1 was analyzed using gas chromatography and mass spectroscopy. The cyanobacterium isolate CHS1 demonstrated tolerance to 8 g/L% NaCl, 35°C and pH 5-9. The characteristic polyunsaturated fatty acid (PUFA) of isolate CHS1, C18:4, was observed in fatty acid methyl esters (FAMEs) extracted from the cell membrane. CHS1 was capable of producing saturated fatty acids (SFA) (e.g., C16:0), monounsaturated fatty acids (MUFA) (e.g., C18:1) and polyunsaturated fatty acids (e.g., C20:5) in the cell membrane. In this study, we hypothesize that one mechanism of cold adaptation displayed by isolate CHS1 is the accumulation of high amounts of PUFA in the cell membrane.


Assuntos
Membrana Celular , Camada de Gelo , Nodularia , Ácidos Graxos , Paquistão
19.
J Oral Rehabil ; 47 Suppl 1: 19-28, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31461788

RESUMO

Craniosynostosis, a severe craniofacial developmental disease, can only be treated with surgery currently. Recent studies have shown that proteoglycans are involved in the suture development. For the bone matrix protein, dentin matrix protein 1 (DMP1), glycosylation on the N-terminal of it could generate a functional proteoglycan form of DMP1 during osteogenesis. We identified that the proteoglycan form of DMP1 (DMP1-PG) is highly expressed in mineralisation front of suture. But, the potential role of DMP1-PG in suture fusion remain unclear. To investigate the role of DMP1-PG in cranial suture fusion and craniofacial bone development. By using a DMP1 glycosylation site mutation mouse model, DMP1-S89G mice, we compared the suture development in it with control mice. We compared the suture phenotypes, bone formation rate, expression levels of bone formation markers in vivo between DMP1-S89G mice and wild-type mice. Meanwhile, cell culture and organ culture were performed to detect the differences in cell differentiation and suture fusion in vitro. Finally, chondroitin sulphate (CHS), as functional component of DMP1-PG, was employed to test whether it could delay the premature suture fusion and the abnormal differentiation of bone mesenchymal stem cells (BMSCs) of DMP1-PG mice. DMP1-S89G mice had premature closure of suture and shorter skull size. Lack of DMP1-PG accelerated bone formation in cranial suture. DMP1-PG maintained the essential stemness of BMSCs in suture through blocking the premature differentiation of BMSCs to osteoblasts. Finally, chondroitin sulphate, a major component of DMP1-PG, successfully delayed the premature suture fusion by organ culture of skull in vitro. DMP1-PG could inhibit premature fusion of cranial suture and maintain the suture through regulating the osteogenic differentiation of BMSCs.


Assuntos
Suturas Cranianas , Osteogênese , Animais , Suturas Cranianas/metabolismo , Proteínas da Matriz Extracelular/metabolismo , Glicosilação , Humanos , Camundongos , Osteoblastos/metabolismo , Crânio
20.
J Cell Biochem ; 120(6): 9631-9638, 2019 06.
Artigo em Inglês | MEDLINE | ID: mdl-30520120

RESUMO

Chondrosarcoma (CHS) is a common malignant bone sarcoma and its occurrence increases with age. microRNAs (miRNAs) are a class of noncoding RNAs that participate in various biological processes and disease pathogenesis by targeting functional messenger RNA (mRNA). However, the modulation of miRNAs in CHS remains largely unknown. In this study, we performed integrative analysis to explore the expression profiles of miRNAs and mRNAs, together with their interaction networks in human CHS tissues and cell lines by RNA-seq (miRNA and mRNA). A total of 133 and 796 differentially expressed miRNAs and mRNAs were identified (|Fold change| ≥ 2 and P-value ≤ 0.5). miRNA-mRNA regulatory interactions between 55 miRNAs and 242 mRNAs were screened by the Pearson correlation analysis and target prediction. mRNAs in the network were enriched to 145 Gene Ontology terms and 35 Kyoto Encyclopedia of Genes and Genomes pathways. Specifically, some key regulators (hub-miRNAs) in the network (miR-622, miR-4539, miR-145, miR-25, and miR-96) were suggested to play important regulatory roles in the pathogenesis of CHS. In addition, functional experiments validated that miR-622 regulated CHS cell proliferation by targeting bone morphogenetic protein 1 (BMP1).


Assuntos
Biomarcadores Tumorais/genética , Condrossarcoma/genética , Redes Reguladoras de Genes , MicroRNAs/genética , RNA Mensageiro/genética , Sequência de Bases , Biomarcadores Tumorais/metabolismo , Proteína Morfogenética Óssea 1/metabolismo , Linhagem Celular Tumoral , Proliferação de Células/genética , Condrossarcoma/patologia , Perfilação da Expressão Gênica , Regulação Neoplásica da Expressão Gênica , Genoma Humano , Humanos , MicroRNAs/metabolismo , RNA Mensageiro/metabolismo , Reprodutibilidade dos Testes , Regulação para Cima/genética
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