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1.
Int J Mol Sci ; 22(19)2021 Sep 24.
Artigo em Inglês | MEDLINE | ID: mdl-34638625

RESUMO

Glycosyltransferase OGT catalyzes the conjugation of O-linked ß-D-N-acetylglucosamine (O-GlcNAc) to Ser and Thr residues of the cellular proteins and regulates many key processes in the cell. Here, we report the identification of OGT as a ubiquitination target of HECT-type E3 ubiquitin (UB) ligase E6AP, whose overexpression in HEK293 cells would induce the degradation of OGT. We also found that the expression of E6AP in HeLa cells with the endogenous expression of the E6 protein of the human papillomavirus (HPV) would accelerate OGT degradation by the proteasome and suppress O-GlcNAc modification of OGT substrates in the cell. Overall, our study establishes a new mechanism of OGT regulation by the ubiquitin-proteasome system (UPS) that mediates the crosstalk between protein ubiquitination and O-GlcNAcylation pathways underlying diverse cellular processes.

3.
Huan Jing Ke Xue ; 42(9): 4558-4565, 2021 Sep 08.
Artigo em Chinês | MEDLINE | ID: mdl-34414756

RESUMO

To investigate the effects of microplastics on soil organic carbon mineralization and the changes in soil enzyme activities, an incubation experiment was conducted whereby single applications of either microplastics or straw, and combined application of both, were added to Dangyang citrus orchard soil. The results showed that the combined application of straw and microplastics significantly affected organic carbon mineralization in the soil, but the single addition of microplastics had no significant effect. Compared with straw alone, the application of a small combined amount of microplastics and straw significantly increased soil organic carbon mineralization by 8.20%, while medium and high amounts of the combined application significantly inhibited soil organic carbon mineralization. The lowest amount of organic carbon mineralization occurred with the highest amount of combined microplastics and straw, 10.13% lower than with straw alone. The addition of microplastics significantly reduced the activity of ß-glucosidase. In particular, a high amount of microplastics significantly decreased the activity of ß-glucosidase, compared with the control, by 20.52%, 43.93%, and 17.79% on the day 1, 6, and 35, respectively. However, straw application alleviated the inhibition effect of microplastic application on soil ß-glucosidase activity. The soil organic carbon mineralization rate was significantly positively correlated with DOC, MBC and ß-glucosidase activity.


Assuntos
Citrus , Solo , Carbono , Microplásticos , Plásticos
4.
Nat Commun ; 12(1): 4413, 2021 07 20.
Artigo em Inglês | MEDLINE | ID: mdl-34285210

RESUMO

Enhanced neovasculogenesis, especially vasculogenic mimicry (VM), contributes to the development of triple-negative breast cancer (TNBC). Breast tumor-initiating cells (BTICs) are involved in forming VM; however, the specific VM-forming BTIC population and the regulatory mechanisms remain undefined. We find that tumor endothelial marker 8 (TEM8) is abundantly expressed in TNBC and serves as a marker for VM-forming BTICs. Mechanistically, TEM8 increases active RhoC level and induces ROCK1-mediated phosphorylation of SMAD5, in a cascade essential for promoting stemness and VM capacity of breast cancer cells. ASB10, an estrogen receptor ERα trans-activated E3 ligase, ubiquitylates TEM8 for degradation, and its deficiency in TNBC resulted in a high homeostatic level of TEM8. In this work, we identify TEM8 as a functional marker for VM-forming BTICs in TNBC, providing a target for the development of effective therapies against TNBC targeting both BTIC self-renewal and neovasculogenesis simultaneously.


Assuntos
Biomarcadores Tumorais/metabolismo , Proteínas dos Microfilamentos/metabolismo , Células-Tronco Neoplásicas/patologia , Neovascularização Patológica/patologia , Receptores de Superfície Celular/metabolismo , Neoplasias de Mama Triplo Negativas/patologia , Animais , Antineoplásicos/farmacologia , Antineoplásicos/uso terapêutico , Biomarcadores Tumorais/antagonistas & inibidores , Mama/patologia , Mama/cirurgia , Carcinogênese/efeitos dos fármacos , Carcinogênese/patologia , Linhagem Celular Tumoral , Autorrenovação Celular/efeitos dos fármacos , Feminino , Humanos , Mastectomia , Camundongos , Proteínas dos Microfilamentos/antagonistas & inibidores , Pessoa de Meia-Idade , Células-Tronco Neoplásicas/efeitos dos fármacos , Neovascularização Patológica/tratamento farmacológico , Receptores de Superfície Celular/antagonistas & inibidores , Neoplasias de Mama Triplo Negativas/irrigação sanguínea , Neoplasias de Mama Triplo Negativas/terapia , Ensaios Antitumorais Modelo de Xenoenxerto
5.
Mol Oncol ; 2021 Jul 10.
Artigo em Inglês | MEDLINE | ID: mdl-34245648

RESUMO

ATM serine/threonine kinase (ATM; previously known as ataxia-telangiectasia mutated) plays a critical role in maintaining genomic stability and regulates multiple downstream pathways, such as DNA repair, cell cycle arrest, and apoptosis. As a serine/threonine kinase, ATM has an array of downstream phosphorylation substrates, including checkpoint effector checkpoint kinase 2 (CHK2). ATM inhibits cell cycle progression by phosphorylating and activating CHK2, which plays an important role in the formation and development of tumors and participates in DNA repair responses after double-stranded DNA breaks. In this study, we used a recently developed mammalian functional genetic screening system to explore a series of ATM substrates and their role in DNA damage to enhance our understanding of the DNA damage response. Ubiquilin 4 (UBQLN4), which belongs to the ubiquilin family characterized by its ubiquitin-like (UBL) and ubiquitin-associated (UBA) domains, was identified as a new substrate for ATM. UBQLN4 is involved in various intracellular processes, such as autophagosome maturation, p21 regulation, and motor axon morphogenesis. However, the biological function of UBQLN4 remains to be elucidated. In this study, we not only identified UBQLN4 as a substrate for ATM, but also found that UBQLN4 interacts with and stabilizes the anti-apoptotic proteins Bcl-2-related protein A1 (BCL2A1) and Bcl-2-like protein 10 (BCL2L10) and prevents mesothelioma cell apoptosis in response to DNA damage. These findings expand our understanding of the role of UBQLN4 in mesothelioma and provide new insights into potential mesothelioma treatments targeting substrates for ATM.

6.
Adv Sci (Weinh) ; 8(15): e2004504, 2021 08.
Artigo em Inglês | MEDLINE | ID: mdl-34050636

RESUMO

Genomic amplification of OTUD7B is frequently found across human cancers. But its role in tumorigenesis is poorly understood. Lysine-specific demethylase 1 (LSD1) is known to execute epigenetic regulation by forming corepressor complex with CoREST/histone deacetylases (HDACs). However, the molecular mechanisms by which cells maintain LSD1/CoREST complex integrity are unknown. Here, it is reported that LSD1 protein undergoes K63-linked polyubiquitination. OTUD7B is responsible for LSD1 deubiquitination at K226/277 residues, resulting in dynamic control of LSD1 binding partner specificity and cellular homeostasis. OTUD7B deficiency increases K63-linked ubiquitination of LSD1, which disrupts LSD1/CoREST complex formation and targets LSD1 for p62-mediated proteolysis. Consequently, OTUD7B deficiency impairs genome-wide LSD1 occupancy and enhances the methylation of H3K4/H3K9, therefore profoundly impacting global gene expression and abrogating breast cancer metastasis. Moreover, physiological fluctuation of OTUD7B modulates cell cycle-dependent LSD1 oscillation, ensuring the G1/S transition. Both OTUD7B and LSD1 proteins are overpresented in high-grade or metastatic human breast cancer, while dysregulation of either protein is associated with poor survival and metastasis. Thus, OTUD7B plays a unique partner-switching role in maintaining the integrity of LSD1/CoREST corepressor complex, LSD1 turnover, and breast cancer metastasis.

7.
J Biol Chem ; 296: 100738, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33957127

RESUMO

Anoctamin-1 (ANO1) (TMEM16A) is a calcium-activated chloride channel that plays critical roles in diverse physiological processes, such as sensory transduction and epithelial secretion. ANO1 levels have been shown to be altered under physiological and pathological conditions, although the molecular mechanisms that control ANO1 protein levels remain unclear. The ubiquitin-proteasome system is known to regulate the levels of numerous ion channels, but little information is available regarding whether and how ubiquitination regulates levels of ANO1. Here, we showed that two E3 ligases, TRIM23 and TRIM21, physically interact with the C terminus of ANO1. In vitro and in vivo assays demonstrated that whereas TRIM23 ubiquitinated ANO1 leading to its stabilization, TRIM21 ubiquitinated ANO1 and induced its degradation. Notably, ANO1 regulation by TRIM23 and TRIM21 is involved in chemical-induced pain sensation, salivary secretion, and heart-rate control in mice, and TRIM23 also mediates ANO1 upregulation induced by epidermal growth factor treatment. Our results suggest that these two antagonistic E3 ligases act together to control ANO1 expression and function. Our findings reveal a previously unrecognized mechanism for regulating ANO1 protein levels and identify a potential molecular link between ANO1 regulation, epidermal growth factor, and other signaling pathways.


Assuntos
Anoctamina-1/metabolismo , Proteínas de Ligação ao GTP/metabolismo , Proteínas de Neoplasias/metabolismo , Ribonucleoproteínas/metabolismo , Células HEK293 , Humanos , Estabilidade Proteica , Proteólise , Ubiquitinação
8.
Blood ; 138(8): 689-705, 2021 Aug 26.
Artigo em Inglês | MEDLINE | ID: mdl-33895792

RESUMO

Ferroportin (FPN), the body's sole iron exporter, is essential for maintaining systemic iron homeostasis. In response to either increased iron or inflammation, hepatocyte-secreted hepcidin binds to FPN, inducing its internalization and subsequent degradation. However, the E3 ubiquitin ligase that underlies FPN degradation has not been identified. Here, we report the identification and characterization of a novel mechanism involving the RNF217-mediated degradation of FPN. A combination of 2 different E3 screens revealed that the Rnf217 gene is a target of Tet1, mediating the ubiquitination and subsequent degradation of FPN. Interestingly, loss of Tet1 expression causes an accumulation of FPN and an impaired response to iron overload, manifested by increased iron accumulation in the liver together with decreased iron in the spleen and duodenum. Moreover, we found that the degradation and ubiquitination of FPN could be attenuated by mutating RNF217. Finally, using 2 conditional knockout mouse lines, we found that knocking out Rnf217 in macrophages increases splenic iron export by stabilizing FPN, whereas knocking out Rnf217 in intestinal cells appears to increase iron absorption. These findings suggest that the Tet1-RNF217-FPN axis regulates iron homeostasis, revealing new therapeutic targets for FPN-related diseases.

9.
Nucleic Acids Res ; 49(7): 3796-3813, 2021 04 19.
Artigo em Inglês | MEDLINE | ID: mdl-33744966

RESUMO

The family of Poly(A)-binding proteins (PABPs) regulates the stability and translation of messenger RNAs (mRNAs). Here we reported that the three members of PABPs, including PABPC1, PABPC3 and PABPC4, were identified as novel substrates for MKRN3, whose deletion or loss-of-function mutations were genetically associated with human central precocious puberty (CPP). MKRN3-mediated ubiquitination was found to attenuate the binding of PABPs to the poly(A) tails of mRNA, which led to shortened poly(A) tail-length of GNRH1 mRNA and compromised the formation of translation initiation complex (TIC). Recently, we have shown that MKRN3 epigenetically regulates the transcription of GNRH1 through conjugating poly-Ub chains onto methyl-DNA bind protein 3 (MBD3). Therefore, MKRN3-mediated ubiquitin signalling could control both transcriptional and post-transcriptional switches of mammalian puberty initiation. While identifying MKRN3 as a novel tissue-specific translational regulator, our work also provided new mechanistic insights into the etiology of MKRN3 dysfunction-associated human CPP.


Assuntos
Hormônio Liberador de Gonadotropina/genética , Proteínas de Ligação a Poli(A)/metabolismo , Precursores de Proteínas/genética , Puberdade Precoce , RNA Mensageiro/metabolismo , Ubiquitina-Proteína Ligases/fisiologia , Animais , Células HEK293 , Células HeLa , Humanos , Camundongos , Camundongos Knockout , Puberdade Precoce/genética , Puberdade Precoce/metabolismo , Ubiquitinação
10.
J Hepatol ; 75(1): 74-85, 2021 07.
Artigo em Inglês | MEDLINE | ID: mdl-33621634

RESUMO

BACKGROUND & AIMS: HBV remains a global threat to human health. It remains incompletely understood how HBV self-restricts in the host during most adult infections. Thus, we performed multi-omics analyses to systematically interrogate HBV-host interactions and the life cycle of HBV. METHODS: RNA-sequencing and ribosome profiling were conducted with cell-based models for HBV replication and gene expression. The novel translational events or products hereby detected were then characterized, and functionally assessed in both cell and mouse models. Moreover, quasi-species analyses of HBV subpopulations were conducted with patients at immune tolerance or activation phases, using next- or third-generation sequencing. RESULTS: We identified EnhI-SL (Enhancer I-stem loop) as a new cis element in the HBV genome; mutations disrupting EnhI-SL were found to elevate viral polymerase expression. Furthermore, while re-discovering HpZ/P', a previously under-explored isoform of HBV polymerase, we also identified HBxZ, a novel short isoform of HBX. Having confirmed their existence, we functionally characterized them as potent suppressors of HBV gene expression and genome replication. Mechanistically, HpZ/P' was found to repress HBV gene expression partially by interacting with, and sequestering SUPV3L1. Activation of the host immune system seemed to reduce the abundance of HBV mutants deficient in HpZ/P' or with disruptions in EnhI-SL. Finally, SRSF2, a host RNA spliceosome protein that is downregulated by HBV, was found to promote the splicing of viral pre-genomic RNA and HpZ/P' biogenesis. CONCLUSION: This study has identified multiple self-restricting HBV-host interactions. In particular, SRSF2-HpZ/P' appeared to constitute another negative feedback mechanism in the HBV life cycle. Targeting host splicing machinery might thus represent a strategy to intervene in HBV-host interactions. LAY SUMMARY: There remain many unknowns about the natural history of HBV infection in adults. Herein, we identified new HBV-host mechanisms which could be responsible for self-restricting infections. Targeting these mechanisms could be a promising strategy for the treatment of HBV infections.

11.
Environ Pollut ; 268(Pt A): 115670, 2021 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-33022546

RESUMO

Nitrous oxide (N2O) is a devastating greenhouse gas and acts as an ozone-depleting agent. Earthworms are a potential source of soil N2O emissions. Application of biochar can mitigate earthworm-induced N2O emissions. However, the underlying interactive mechanism between earthworms and biochar in soil N2O emissions is still unclear. A 35-day laboratory experiment was conducted to examine the soil N2O emission dynamics for four different treatments, earthworm presence with biochar application (EC), earthworm presence without biochar application (E), earthworm absence with biochar application (C) and earthworm absence without biochar application, and the control. Results indicated a negative impact of biochar on earthworm activity, displaying a significantly (p ≤ 0.05) lower survival rate and biomass of earthworms in treatment EC than E. Compared with the control, earthworm presence significantly (p ≤ 0.05) increased cumulative N2O emissions, while application of biochar in the presence of earthworms significantly (p ≤ 0.05) decreased cumulative N2O emissions (485 and 690 µg kg-1 for treatments EC and E, respectively). Treatments E and EC significantly (p ≤ 0.05) increased soil microbial biomass carbon (MBC), ammonium (NH4+-N), nitrate (NO3-N), and dissolved organic carbon (DOC) content and soil pH as compared with the control. The gene copy number of 16 S rRNA, AOA, AOB, nirS, and nosZ increased for all treatments when compared with the control; however, a significant (p ≤ 0.05) difference among the studied genes was only observed for the nosZ gene (2.05 and 2.56 × 106 gene copies g-1 soil for treatments E and EC, respectively). Earthworm-induced soil N2O emissions were significantly (p ≤ 0.05) reduced by biochar addition. The possible underlying mechanisms may include: (1) short-term negative impacts on earthworm activity; (2) a change of functional gene abundance in earthworm casts; and (3) an increase in soil pH due to addition of biochar.


Assuntos
Oligoquetos , Solo , Animais , Carvão Vegetal , Óxido Nitroso/análise , Óxido Nitroso/toxicidade
12.
Sci Total Environ ; 756: 143845, 2021 Feb 20.
Artigo em Inglês | MEDLINE | ID: mdl-33277011

RESUMO

Soil temperature is an important determinant of carbon (C) and nitrogen (N) cycling in terrestrial ecosystems, but its effects on soil organic carbon (SOC) and total nitrogen (TN) dynamics as well as rice biomass in rice paddy ecosystems are not fully understood. We conducted a five-year soil warming experiment in a single-cropping paddy field in Japan. Soil temperatures were elevated by approximate 2 °C with heating wires during the rice growing season and by approximate 1 °C with nighttime thermal blankets during the fallow season. Soil samples were collected in autumn after rice harvest and in spring after fallow each year, and anaerobically incubated at 30 °C for four weeks to determine soil C decomposition and N mineralization potentials. The SOC and TN contents, rice biomass, dissolved organic carbon (DOC) and microbial biomass carbon (MBC) concentrations were measured in the study. Soil warming did not significantly enhance rice aboveground and root biomasses, but it significantly decreased SOC and TN contents and thus decreased soil C decomposition and N mineralization potentials due to depletion of available C and N. Moreover, soil warming significantly decreased DOC concentration but significantly increased MBC concentration. The ratios of C decomposition potential to N mineralization potential, decomposition potential to SOC, and N mineralization to TN were not affected by soil warming. There were significant seasonal and annual variations in SOC, C decomposition and N mineralization potentials, soil DOC and MBC under each temperature treatments. Our study implied that soil warming can decrease soil C and N stocks in paddy ecosystem probably via stimulating microbial activities and accelerating the depletion of DOC. This study further highlights the importance of long-term in situ observation of C and N dynamics and their availabilities in rice paddy ecosystems under increasing global warming scenarios.


Assuntos
Oryza , Solo , Carbono/análise , Ecossistema , Japão , Microbiologia do Solo
14.
J Steroid Biochem Mol Biol ; 206: 105788, 2021 02.
Artigo em Inglês | MEDLINE | ID: mdl-33227378

RESUMO

Congenital lipoid adrenal hyperplasia (LCAH), as the most severe form of congenital adrenal hyperplasia (CAH), is caused by mutations in the steroidogenic acute regulatory protein (STAR). Affected patients were typically characterized by adrenal insufficiency in the first year of life and present with female external genitalia regardless of karyotype. Non-classic LCAH patients usually present from 2 to 4 years old with glucocorticoid deficiency and mild mineralocorticoid deficiency, even develop naturally masculinized external genitalia at birth when they have 46,XY karyotype. We described thirty patients from unrelated Chinese families, including three non-classic LCAH ones. Four novel mutations were reported, including c.556A > G, c.179-15G > T, c.695delG and c.306 + 3_c.306 + 6delAAGT. The c.772C > T is the most common STAR mutation in Chinese population, suggesting a possibility of founder effect. Enzymatic activity assay combined with clinical characteristics showed a good genotype-phenotype correlation in this study. Residual STAR activity more than 20 % may be correlated with non-classic LCAH phenotype. We support the perspective that onset age may be affected by multiple factors and masculinization should be the main weighting factor for diagnosis of non-classic LCAH. Compared with 46,XX LCAH patients, less 46,XY ones were found in our report. A less comprehensive inspection and an easy diagnosis due to classical phenotype both would reduce the possibility of 46,XY LCAH patients to be referred to specialists or geneticists.


Assuntos
Hiperplasia Suprarrenal Congênita/genética , Insuficiência Adrenal/genética , Transtorno 46,XY do Desenvolvimento Sexual/genética , Glucocorticoides/genética , Fosfoproteínas/genética , Hiperplasia Suprarrenal Congênita/epidemiologia , Hiperplasia Suprarrenal Congênita/patologia , Insuficiência Adrenal/patologia , Pré-Escolar , China/epidemiologia , Transtorno 46,XY do Desenvolvimento Sexual/epidemiologia , Transtorno 46,XY do Desenvolvimento Sexual/patologia , Feminino , Glucocorticoides/deficiência , Humanos , Cariótipo , Masculino , Mutação/genética , Fenótipo
15.
Autophagy ; : 1-17, 2020 Nov 04.
Artigo em Inglês | MEDLINE | ID: mdl-33143524

RESUMO

Senile osteoporosis (OP) is often concomitant with decreased autophagic activity. OPTN (optineurin), a macroautophagy/autophagy (hereinafter referred to as autophagy) receptor, is found to play a pivotal role in selective autophagy, coupling autophagy with bone metabolism. However, its role in osteogenesis is still mysterious. Herein, we identified Optn as a critical molecule of cell fate decision for bone marrow mesenchymal stem cells (MSCs), whose expression decreased in aged mice. Aged mice revealed osteoporotic bone loss, elevated senescence of MSCs, decreased osteogenesis, and enhanced adipogenesis, as well as optn-/ - mice. Importantly, restoring Optn by transplanting wild-type MSCs to optn-/ - mice or infecting optn-/ - mice with Optn-containing lentivirus rescued bone loss. The introduction of a loss-of-function mutant of OptnK193R failed to reestablish a bone-fat balance. We further identified FABP3 (fatty acid binding protein 3, muscle and heart) as a novel selective autophagy substrate of OPTN. FABP3 promoted adipogenesis and inhibited osteogenesis of MSCs. Knockdown of FABP3 alleviated bone loss in optn-/ - mice and aged mice. Our study revealed that reduced OPTN expression during aging might lead to OP due to a lack of FABP3 degradation via selective autophagy. FABP3 accumulation impaired osteogenesis of MSCs, leading to the occurrence of OP. Thus, reactivating OPTN or inhibiting FABP3 would open a new avenue to treat senile OP.Abbreviations: ADIPOQ: adiponectin, C1Q and collagen domain containing; ALPL: alkaline phosphatase, liver/bone/kidney; BGLAP/OC/osteocalcin: bone gamma carboxyglutamate protein; BFR/BS: bone formation rate/bone surface; CALCOCO2/NDP52: calcium binding and coiled-coil domain 2; CDKN1A/p21: cyclin-dependent kinase inhibitor 1A; CDKN2A/p16: cyclin dependent kinase inhibitor 2A; CDKN2B/p15: cyclin dependent kinase inhibitor 2B; CEBPA: CCAAT/enhancer binding protein (C/EBP), alpha; COL1A1: collagen, type I, alpha 1; Ct. BV/TV: cortical bone volume fraction; Ct. Th: cortical thickness; Es. Pm: endocortical perimeter; FABP4/Ap2: fatty acid binding protein 4, adipocyte; H2AX: H2A.X variant histone; HE: hematoxylin and eosin; MAP1LC3B: microtubule-associated protein 1 light chain 3 beta; MAR: mineral apposition rate; MSCs: bone marrow mesenchymal stem cells; NBR1: NBR1, autophagy cargo receptor; OP: osteoporosis; OPTN: optineurin; PDB: Paget disease of bone; PPARG: peroxisome proliferator activated receptor gamma; Ps. Pm: periosteal perimeter; qRT-PCR: quantitative real-time PCR; γH2AX: Phosphorylation of the Serine residue of H2AX; ROS: reactive oxygen species; RUNX2: runt related transcription factor 2; SA-GLB1: senescence-associated (SA)-GLB1 (galactosidase, beta 1); SP7/Osx/Osterix: Sp7 transcription factor 7; SQSTM1/p62: sequestosome 1; TAX1BP1: Tax1 (human T cell leukemia virus type I) binding protein 1; Tb. BV/TV: trabecular bone volume fraction; Tb. N: trabecular number; Tb. Sp: trabecular separation; Tb. Th: trabecular thickness; µCT: micro computed tomography.

16.
Biochem Biophys Res Commun ; 529(4): 1025-1032, 2020 09 03.
Artigo em Inglês | MEDLINE | ID: mdl-32819560

RESUMO

Liver kinase B1 (LKB1), a tumour suppressor, participates in many cellular processes, including cell survival, growth, apoptosis, transformation, and metabolism. Upon performing yeast two-hybrid screening, co-immunoprecipitation, and GST pull-down, we identified that BRCA1-associated protein 1 (BAP1), a deubiquitinase, interacts with LKB1. Immunoblotting was performed to examine the effect of BAP1 on the activation of 5' AMP-activated protein kinase (AMPK) and mammalian target of rapamycin (mTOR), downstream of LKB1. The relationship between BAP1 deficiency and cancer cell proliferation was examined using cell survival assay and soft agar assay. qRT-PCR and oil red O staining were performed to evaluate lipid synthesis. Our findings reveal that BAP1 deubiquitinates LKB1, inhibits its degradation, and stabilises it, thereby affecting AMPK activation and downstream mTOR activity. BAP1 deficiency may enhance cellular proliferation as well as lipid synthesis.


Assuntos
Proteínas Quinases Ativadas por AMP/metabolismo , Proteínas Serina-Treonina Quinases/metabolismo , Transdução de Sinais , Proteínas Supressoras de Tumor/metabolismo , Ubiquitina Tiolesterase/metabolismo , Ubiquitinação , Animais , Linhagem Celular , Proliferação de Células , Sobrevivência Celular , Humanos , Lipídeos/biossíntese , Camundongos , Neoplasias/metabolismo , Neoplasias/patologia , Ligação Proteica , Estabilidade Proteica , Especificidade por Substrato , Serina-Treonina Quinases TOR/metabolismo , Proteínas Supressoras de Tumor/deficiência , Ubiquitina Tiolesterase/deficiência
17.
Environ Pollut ; 266(Pt 3): 115292, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32814273

RESUMO

The incorporation of crop straw with fertilization is beneficial for soil carbon sequestration and cropland fertility improvement. Yet, relatively little is known about how fertilization regulates the emissions of the greenhouse gas nitrous oxide (N2O) in response to straw incorporation, particularly in soils subjected to long-term fertilization regimes. Herein, the arable soil subjected to a 31-year history of five inorganic or organic fertilizer regimes (unfertilized; chemical fertilizer application, NPK; 200% NPK application, 2 × NPK; manure application, M; NPK plus manure application, NPKM) was incubated with and without rice straw to evaluate how historical fertilization influences the impact of straw addition on N2O emissions. The results showed that compared to the unfertilized treatment, historical fertilization strongly increased N2O emissions by 0.48- to 34-fold, resulting from increased contents of hot water-extracted organic carbon (HWEOC), NO3-, and available phosphorus (Olsen-P). Straw addition had little impact on N2O emission from the unfertilized and NPK treatments, primarily due to Olsen-P limitation. In contrast, straw addition increased N2O emissions by 102-316% from the 2 × NPK, M, and NPKM treatments as compared to the corresponding straw-unamended treatments. These results indicated that N2O emissions in response to straw addition were largely regulated by historical fertilization. The N2O emissions were closely associated with the depletion of NO3- and decoupled from change in NH4+ content, suggesting that NO3- was the main substrate for N2O production upon straw addition. The stoichiometric ratios of HWEOC to mineral N and mineral N to Olsen-P were key factors affecting N2O emissions, underscoring the importance of resource stoichiometry in regulating N2O emissions. In conclusion, historical fertilization largely regulated the impacts of crop straw incorporation on N2O emissions via shifts in NO3- depletion and the stoichiometry of HWEOC, mineral N, and Olsen-P.


Assuntos
Gases de Efeito Estufa , Óxido Nitroso/análise , Agricultura , China , Fertilizantes , Nitrogênio , Solo
18.
Sci Total Environ ; 744: 140632, 2020 Nov 20.
Artigo em Inglês | MEDLINE | ID: mdl-32688003

RESUMO

Winter-flooded rice paddy field (FR), characterized by water conserved in the field during the fallow period, is a typical cropping system in southwest China, leading to considerable methane (CH4) emissions. The effect of nitrogen (N) fertilization on CH4 emissions during rice-growing seasons is well studied in FR, further studies covering N fertilizer applied in the rice-growing seasons affects CH4 emissions during the subsequent fallow period is needed. Therefore, a field experiment was conducted in an FR of Sichuan province, China, with conventional N fertilized (CN) and N unfertilized (NN) treatments. The cumulative CH4 emission from CN treatment during the rice-growing season and the subsequent fallow period was 389 ± 29.4 and 158 ± 31.2 kg C ha-1, which were increased by 29.5% and 395% in comparison with the NN treatment, indicting N applied during the rice growing-season significantly facilitated CH4 emission during the subsequent fallow period. During the rice-growing season, higher CH4 emission from CN treatment could be attributed to elevated soil dissolved organic carbon (DOC) content that might have provided sufficient substrates for CH4 production. During the fallow period, as compared to NN treatment, higher CH4 emissions from CN treatment could be explained by greater linear regression slopes between CH4 fluxes, soil temperature and DOC to dissolved inorganic N (DIN) (DOC/DIN) ratio. Moreover, the structural equation model (SEM) described that the soil temperature exhibited the most significant effects on CH4 emissions for both treatments during the rice-growing season and subsequent fallow period. These findings are a major step forward to showing that N fertilizer applied in the rice-growing season could also affect CH4 emission during the subsequent fallow period, accompanying other soil parameters controlling CH4 emission.

19.
Artigo em Inglês | MEDLINE | ID: mdl-32599729

RESUMO

Bryophytes are popular biomonitoring plants for atmospheric environments. The objectives of this study were to examine the characteristics of bryophyte communities, determine a suitable monitor species, and assess urban atmospheric environment quality by the joint use of bryophyte features and chemical properties in a large city in China. A pleurocarpous feather moss Haplocladium angustifolium was recognized as a good biomonitor of atmospheric deposition in central China by investigating bryophyte communities and habitat environment in various ecological function regions of the urban areas in Wuhan. The concentrations of trace elements, including As, Cd, Co, Cr, Cu, Mn, Ni, V, Pb, and Zn, in moss and soil samples from 25 sampling sites were analyzed by inductively coupled plasma mass spectrometry. The concentrations of Cd and Zn in Haplocladium angustifolium collected from the entire study area were much higher than those in substrate soil. Cd was at the highest ecological risk level among the 10 elements, which contributed 34.5% to the potential ecological risk index (RI). An RI value of 392.8 indicated that urban atmospheric quality in Wuhan was in a considerable potential ecological risk. The index of atmospheric purity, regarding species richness, cover, and frequency of bryophytes, was spatially and negatively correlated with RI, also demonstrated the atmospheric quality. Effective measures should be considered to alleviate certain airborne trace element contamination and protect the environment and human health in this metropolis.


Assuntos
Briófitas , Monitoramento Ambiental , Metais Pesados , Poluentes do Solo , Briófitas/química , China , Cidades , Humanos , Medição de Risco
20.
PeerJ ; 8: e9267, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32566397

RESUMO

Background: Untreated wastewater carries substantial amount of heavy metals and causes potential ecological risks to the environment, food quality, soil health and sustainable agriculture. Methodology: In order to reduce the incidence of nickel (Ni2+) contamination in soils, two separate experiments (incubation and greenhouse) were conducted to investigate the potentials of rice straw biochar and elemental sulfur in remediating Ni2+ polluted soil due to the irrigation with wastewater. Five incubation periods (1, 7, 14, 28 and 56 days), three biochar doses (0, 10 and 20 g kg-1 of soil) and two doses of sulfur (0 and 5 g kg-1 of soil) were used in the incubation experiment then the Ni2+ was extracted from the soil and analyzed, while ryegrass seeds Lolium perenne L. (Poales: Poaceae) and the same doses of biochar and sulfur were used in the greenhouse experiment then the plants Ni2+-uptake was determined. Results: The results of the incubation experiment revealed a dose-dependent reduction of DTPA-extractable Ni2+ in soils treated with biochar. Increasing the biochar dose from 0 g kg-1 (control) to 10 or 20 g kg-1 (treatments) decreased the DTPA-extractable Ni2+ from the soil by 24.6% and 39.4%, respectively. The application of sulfur increased the Ni2+-uptake by ryegrass plant which was used as hyper-accumulator of heavy metals in the green house experiment. However, the biochar decreased the Ni2+-uptake by the plant therefore it can be used as animal feed. Conclusions: These results indicate that the biochar and sulfur could be applied separately to remediate the Ni2+-contaminated soils either through adsorbing the Ni2+ by biochar or increasing the Ni2+ availability by sulfur to be easily uptaken by the hyper-accumulator plant, and hence promote a sustainable agriculture.

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