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1.
Commun Biol ; 7(1): 852, 2024 Jul 12.
Artigo em Inglês | MEDLINE | ID: mdl-38997325

RESUMO

Astrocytes play a key role in the regulation of synaptic strength and are thought to orchestrate synaptic plasticity and memory. Yet, how specifically astrocytes and their neuroactive transmitters control learning and memory is currently an open question. Recent experiments have uncovered an astrocyte-mediated feedback loop in CA1 pyramidal neurons which is started by the release of endocannabinoids by active neurons and closed by astrocytic regulation of the D-serine levels at the dendrites. D-serine is a co-agonist for the NMDA receptor regulating the strength and direction of synaptic plasticity. Activity-dependent D-serine release mediated by astrocytes is therefore a candidate for mediating between long-term synaptic depression (LTD) and potentiation (LTP) during learning. Here, we show that the mathematical description of this mechanism leads to a biophysical model of synaptic plasticity consistent with the phenomenological model known as the BCM model. The resulting mathematical framework can explain the learning deficit observed in mice upon disruption of the D-serine regulatory mechanism. It shows that D-serine enhances plasticity during reversal learning, ensuring fast responses to changes in the external environment. The model provides new testable predictions about the learning process, driving our understanding of the functional role of neuron-glia interaction in learning.


Assuntos
Astrócitos , Plasticidade Neuronal , Reversão de Aprendizagem , Animais , Astrócitos/fisiologia , Astrócitos/metabolismo , Plasticidade Neuronal/fisiologia , Camundongos , Reversão de Aprendizagem/fisiologia , Serina/metabolismo , Modelos Neurológicos , Receptores de N-Metil-D-Aspartato/metabolismo
2.
Transl Psychiatry ; 14(1): 281, 2024 Jul 09.
Artigo em Inglês | MEDLINE | ID: mdl-38982054

RESUMO

Frailty is a common age-related clinical syndrome characterized by a decline in the function of multiple organ systems, increased vulnerability to stressors, and a huge socio-economic burden. Despite recent research efforts, the physiopathological mechanisms underlying frailty remain elusive and biomarkers able to predate its occurrence in the early stages are still lacking. Beyond its physical component, cognitive decline represents a critical domain of frailty associated with higher risk of adverse health outcomes. We measured by High-Performance Liquid Chromatography (HPLC) a pool of serum amino acids including L-glutamate, L-aspartate, glycine, and D-serine, as well as their precursors L-glutamine, L-asparagine, and L-serine in a cohort of elderly subjects encompassing the entire continuum from fitness to frailty. These amino acids are known to orchestrate excitatory and inhibitory neurotransmission, and in turn, to play a key role as intermediates of energy homeostasis and in liver, kidney, muscle, and immune system metabolism. To comprehensively assess frailty, we employed both the Edmonton Frail Scale (EFS), as a practical tool to capture the multidimensionality of frailty, and the frailty phenotype, as a measure of physical function. We found that D-serine and D-/Total serine ratio were independent predictors of EFS but not of physical frailty. Furthermore, higher levels of glycine, glycine/L-serine and D-/Total serine were associated with worse cognition and depressive symptoms in the frail group. These findings suggest that changes in peripheral glycine and serine enantiomers homeostasis may represent a novel biochemical correlate of frailty.


Assuntos
Biomarcadores , Disfunção Cognitiva , Idoso Fragilizado , Glicina , Serina , Humanos , Masculino , Idoso , Serina/sangue , Feminino , Glicina/sangue , Biomarcadores/sangue , Disfunção Cognitiva/sangue , Idoso de 80 Anos ou mais , Fragilidade/sangue
3.
Nat Commun ; 15(1): 5775, 2024 Jul 10.
Artigo em Inglês | MEDLINE | ID: mdl-38982125

RESUMO

The epitranscriptome includes a diversity of RNA modifications that influence gene expression. N3-methylcytidine (m3C) mainly occurs in the anticodon loop (position C32) of certain tRNAs yet its role is poorly understood. Here, using HAC-Seq, we report comprehensive METTL2A/2B-, METTL6-, and METTL2A/2B/6-dependent m3C profiles in human cells. METTL2A/2B modifies tRNA-arginine and tRNA-threonine members, whereas METTL6 modifies the tRNA-serine family. However, decreased m3C32 on tRNA-Ser-GCT isodecoders is only observed with combined METTL2A/2B/6 deletion. Ribo-Seq reveals altered translation of genes related to cell cycle and DNA repair pathways in METTL2A/2B/6-deficient cells, and these mRNAs are enriched in AGU codons that require tRNA-Ser-GCT for translation. These results, supported by reporter assays, help explain the observed altered cell cycle, slowed proliferation, and increased cisplatin sensitivity phenotypes of METTL2A/2B/6-deficient cells. Thus, we define METTL2A/2B/6-dependent methylomes and uncover a particular requirement of m3C32 tRNA modification for serine codon-biased mRNA translation of cell cycle, and DNA repair genes.


Assuntos
Ciclo Celular , Códon , Dano ao DNA , Biossíntese de Proteínas , RNA Mensageiro , RNA de Transferência , Serina , Humanos , Ciclo Celular/genética , Códon/genética , RNA Mensageiro/metabolismo , RNA Mensageiro/genética , RNA de Transferência/genética , RNA de Transferência/metabolismo , Serina/metabolismo , Metiltransferases/metabolismo , Metiltransferases/genética , Citidina/análogos & derivados , Citidina/metabolismo , Citidina/genética , Reparo do DNA , Células HEK293 , Anticódon/genética
4.
Biophys Chem ; 311: 107272, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-38824845

RESUMO

In the presented work, a study on the solubility and intermolecular interactions of l-serine and L-cysteine was carried out in binary mixtures of H2O + dimethylformamide (DMF), H2O + dimethylsulfoxide (DMSO), and H2O + acetonitrile (ACN) in the temperature range of T = 288.15 K to 308.15 K. l-serine exhibited the highest solubility in water, while L-cysteine was more soluble in water-DMF. The solvation process was assessed through standard Gibbs energy calculations, indicating the solvation stability order: water-ACN > water-DMSO > water-DMF for l-serine, and water-DMF > water-DMSO > water-ACN for L-cysteine. This study also explored the influence of these amino acids on solvent-solvent interactions, revealing changes in chemical entropies and self-association patterns within the binary solvent mixtures.


Assuntos
Acetonitrilas , Cisteína , Dimetil Sulfóxido , Dimetilformamida , Serina , Solubilidade , Temperatura , Água , Dimetil Sulfóxido/química , Serina/química , Acetonitrilas/química , Água/química , Cisteína/química , Dimetilformamida/química , Termodinâmica , Solventes/química
5.
BMC Biotechnol ; 24(1): 44, 2024 Jun 26.
Artigo em Inglês | MEDLINE | ID: mdl-38926833

RESUMO

BACKGROUND: Mammalian display is an appealing technology for therapeutic antibody development. Despite the advantages of mammalian display, such as full-length IgG display with mammalian glycosylation and its inherent ability to select antibodies with good biophysical properties, the restricted library size and large culture volumes remain challenges. Bxb1 serine integrase is commonly used for the stable genomic integration of antibody genes into mammalian cells, but presently lacks the efficiency required for the display of large mammalian display libraries. To increase the Bxb1 integrase-mediated stable integration efficiency, our study investigates factors that potentially affect the nuclear localization of Bxb1 integrase. METHODS: In an attempt to enhance Bxb1 serine integrase-mediated integration efficiency, we fused various nuclear localization signals (NLS) to the N- and C-termini of the integrase. Concurrently, we co-expressed multiple proteins associated with nuclear transport to assess their impact on the stable integration efficiency of green fluorescent protein (GFP)-encoding DNA and an antibody display cassette into the genome of Chinese hamster ovary (CHO) cells containing a landing pad for Bxb1 integrase-mediated integration. RESULTS: The nucleoplasmin NLS from Xenopus laevis, when fused to the C-terminus of Bxb1 integrase, demonstrated the highest enhancement in stable integration efficiency among the tested NLS fusions, exhibiting over a 6-fold improvement compared to Bxb1 integrase lacking an NLS fusion. Subsequent additions of extra NLS fusions to the Bxb1 integrase revealed an additional 131% enhancement in stable integration efficiency with the inclusion of two copies of C-terminal nucleoplasmin NLS fusions. Further improvement was achieved by co-expressing the Ran GTPase-activating protein (RanGAP). Finally, to validate the applicability of these findings to more complex proteins, the DNA encoding the membrane-bound clinical antibody abrilumab was stably integrated into the genome of CHO cells using Bxb1 integrase with two copies of C-terminal nucleoplasmin NLS fusions and co-expression of RanGAP. This approach demonstrated over 14-fold increase in integration efficiency compared to Bxb1 integrase lacking an NLS fusion. CONCLUSIONS: This study demonstrates that optimizing the NLS sequence fusion for Bxb1 integrase significantly enhances the stable genomic integration efficiency. These findings provide a practical approach for constructing larger libraries in mammalian cells through the stable integration of genes into a genomic landing pad.


Assuntos
Cricetulus , Integrases , Sinais de Localização Nuclear , Animais , Células CHO , Integrases/metabolismo , Integrases/genética , Sinais de Localização Nuclear/metabolismo , Sinais de Localização Nuclear/genética , Núcleo Celular/metabolismo , Núcleo Celular/genética , Serina/metabolismo , Proteínas de Fluorescência Verde/metabolismo , Proteínas de Fluorescência Verde/genética , Cricetinae , Xenopus laevis/metabolismo
7.
Exp Cell Res ; 440(1): 114133, 2024 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-38897409

RESUMO

Mouse HORMAD1 is a phospho-protein involved in multiple functions during meiotic prophase I. To obtain insight into the significance of its phosphorylation, we generated phospho-specific antibodies against two serine residues, Ser307 and Ser378, representing each of two serine clusters in mouse HORMAD1. The Ser307 phosphorylation is detectable from early leptotene substage in both wild-type and Spo11-/- spermatocytes, indicating that Ser307 is a primary and SPO11-independent phosphorylation site. In contrast, the Ser378 phosphorylation is negligible at earlier substages in wild-type and Spo11-/- spermatocytes. After mid-zygotene substage, the Ser378 phosphorylation is abundant on unsynapsed chromosome axes in wild-type spermatocytes and is detected only in a part of unsynapsed chromosome axes in Spo11-/- spermatocytes. We also generated a non-phosphorylated Ser307-specific antibody and found that Ser307 is phosphorylated on sex chromosome axes but is almost entirely unphosphorylated on desynapsed chromosome axes in diplotene spermatocytes. These results demonstrated a substage-specific phosphorylation status of mouse HORMAD1, which might be associated with multiple substage-specific functions.


Assuntos
Prófase Meiótica I , Serina , Espermatócitos , Animais , Fosforilação , Masculino , Camundongos , Serina/metabolismo , Espermatócitos/metabolismo , Endodesoxirribonucleases/metabolismo , Endodesoxirribonucleases/genética , Camundongos Endogâmicos C57BL , Proteínas de Ciclo Celular/metabolismo , Proteínas de Ciclo Celular/genética , Camundongos Knockout , Cromossomos Sexuais/genética , Cromossomos Sexuais/metabolismo
8.
J Proteome Res ; 23(7): 2474-2494, 2024 Jul 05.
Artigo em Inglês | MEDLINE | ID: mdl-38850255

RESUMO

Protein glycosylation is a ubiquitous process observed across all domains of life. Within the human pathogen Acinetobacter baumannii, O-linked glycosylation is required for virulence; however, the targets and conservation of glycosylation events remain poorly defined. In this work, we expand our understanding of the breadth and site specificity of glycosylation within A. baumannii by demonstrating the value of strain specific glycan electron-transfer/higher-energy collision dissociation (EThcD) triggering for bacterial glycoproteomics. By coupling tailored EThcD-triggering regimes to complementary glycopeptide enrichment approaches, we assessed the observable glycoproteome of three A. baumannii strains (ATCC19606, BAL062, and D1279779). Combining glycopeptide enrichment techniques including ion mobility (FAIMS), metal oxide affinity chromatography (titanium dioxide), and hydrophilic interaction liquid chromatography (ZIC-HILIC), as well as the use of multiple proteases (trypsin, GluC, pepsin, and thermolysis), we expand the known A. baumannii glycoproteome to 33 unique glycoproteins containing 42 glycosylation sites. We demonstrate that serine is the sole residue subjected to glycosylation with the substitution of serine for threonine abolishing glycosylation in model glycoproteins. An A. baumannii pan-genome built from 576 reference genomes identified that serine glycosylation sites are highly conserved. Combined this work expands our knowledge of the conservation and site specificity of A. baumannii O-linked glycosylation.


Assuntos
Acinetobacter baumannii , Glicoproteínas , Polissacarídeos , Proteômica , Serina , Acinetobacter baumannii/genética , Acinetobacter baumannii/metabolismo , Acinetobacter baumannii/química , Glicosilação , Serina/metabolismo , Serina/química , Proteômica/métodos , Glicoproteínas/metabolismo , Glicoproteínas/química , Glicoproteínas/genética , Polissacarídeos/metabolismo , Polissacarídeos/química , Proteínas de Bactérias/metabolismo , Proteínas de Bactérias/química , Proteínas de Bactérias/genética , Glicopeptídeos/análise , Glicopeptídeos/química , Glicopeptídeos/metabolismo , Cromatografia Líquida
10.
Trends Neurosci ; 47(7): 480-490, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38862330

RESUMO

α-Synuclein (αS) is an abundant presynaptic protein that regulates neurotransmission. It is also a key protein implicated in a broad class of neurodegenerative disorders termed synucleinopathies, including Parkinson's disease (PD) and Lewy body dementia (LBD). Pathological αS deposits in these diseases, Lewy bodies (LBs)/neurites (LNs), contain about 90% of αS in its phospho-serine129 (pS129) form. Therefore, pS129 is widely used as a surrogate marker of pathology. However, recent findings demonstrate that pS129 is also physiologically triggered by neuronal activity to positively regulate synaptic transmission. In this opinion article, we contrast the literature on pathological and physiological pS129, with a special focus on the latter. We emphasize that pS129 is ambiguous and knowledge about the context is necessary to correctly interpret changes in pS129.


Assuntos
alfa-Sinucleína , alfa-Sinucleína/metabolismo , Humanos , Fosforilação/fisiologia , Animais , Serina/metabolismo , Doença de Parkinson/metabolismo , Transmissão Sináptica/fisiologia , Sinucleinopatias/metabolismo
11.
Emerg Microbes Infect ; 13(1): 2368221, 2024 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-38932432

RESUMO

A positive-sense (+) single-stranded RNA (ssRNA) virus (e.g. enterovirus A71, EV-A71) depends on viral polypeptide translation for initiation of virus replication after entry. We reported that EV-A71 hijacks Hsp27 to induce hnRNP A1 cytosol redistribution to initiate viral protein translation, but the underlying mechanism is still elusive. Here, we show that phosphorylation-deficient Hsp27-3A (Hsp27S15/78/82A) and Hsp27S78A fail to translocate into the nucleus and induce hnRNP A1 cytosol redistribution, while Hsp27S15A and Hsp27S82A display similar effects to the wild type Hsp27. Furthermore, we demonstrate that the viral 2A protease (2Apro) activity is a key factor in regulating Hsp27/hnRNP A1 relocalization. Hsp27S78A dramatically decreases the IRES activity and viral replication, which are partially reduced by Hsp27S82A. However, Hsp27S15A displays the same activity as the wild-type Hsp27. Peptide S78 potently suppresses EV-A71 protein translation and reproduction through blockage of EV-A71-induced Hsp27 phosphorylation and Hsp27/hnRNP A1 relocalization. A point mutation (S78A) on S78 impairs its inhibitory functions on Hsp27/hnRNP A1 relocalization and viral replication. Taken together, we demonstrate the importance of Ser78 phosphorylation of Hsp27 regulated by virus infection in nuclear translocation, hnRNP A1 cytosol relocation, and viral replication, suggesting a new path (such as peptide S78) for target-based antiviral strategy.


Assuntos
Enterovirus Humano A , Proteínas de Choque Térmico HSP27 , Ribonucleoproteína Nuclear Heterogênea A1 , Replicação Viral , Enterovirus Humano A/efeitos dos fármacos , Enterovirus Humano A/fisiologia , Enterovirus Humano A/genética , Fosforilação , Humanos , Replicação Viral/efeitos dos fármacos , Ribonucleoproteína Nuclear Heterogênea A1/metabolismo , Ribonucleoproteína Nuclear Heterogênea A1/genética , Proteínas de Choque Térmico HSP27/metabolismo , Proteínas de Choque Térmico HSP27/genética , Infecções por Enterovirus/virologia , Infecções por Enterovirus/metabolismo , Antivirais/farmacologia , Proteínas Virais/metabolismo , Proteínas Virais/genética , Serina/metabolismo , Células HeLa , Biossíntese de Proteínas , Cisteína Endopeptidases/metabolismo , Cisteína Endopeptidases/genética , Chaperonas Moleculares/metabolismo , Chaperonas Moleculares/genética , Proteínas de Choque Térmico
12.
Mol Brain ; 17(1): 35, 2024 Jun 10.
Artigo em Inglês | MEDLINE | ID: mdl-38858726

RESUMO

The brain responds to experience through modulation of synaptic transmission, that is synaptic plasticity. An increase in the strength of synaptic transmission is manifested as long-term potentiation (LTP), while a decrease in the strength of synaptic transmission is expressed as long-term depression (LTD). Most of the studies of synaptic plasticity have been carried out by induction via electrophysiological stimulation. It is largely unknown in which behavioural tasks such synaptic plasticity occurs. Moreover, some stimuli can induce both LTP and LTD, thus making it difficult to separately study the different forms of synaptic plasticity. Two studies have shown that an aversive memory task - inhibitory avoidance learning and contextual fear conditioning - physiologically and selectively induce LTP and an LTP-like molecular change, respectively, in the hippocampus in vivo. Here, we show that a non-aversive behavioural task - exploration of new space - physiologically and selectively elicits a biochemical change in the hippocampus that is a hallmark of LTP. Specifically, we found that exploration of new space induces an increase in the phosphorylation of GluA1(Ser831), without affecting the phosphorylation of GluA1(Ser845), which are biomarkers of early-LTP and not NMDAR-mediated LTD. We also show that exploration of new space engenders the phosphorylation of the translational regulator S6K and the expression of Arc, which are features of electrophysiologically-induced late-LTP in the hippocampus. Therefore, our results show that exploration of new space is a novel non-aversive behavioural paradigm that elicits molecular changes in vivo that are analogous to those occurring during early- and late-LTP, but not during NMDAR-mediated LTD.


Assuntos
Proteínas do Citoesqueleto , Hipocampo , Potenciação de Longa Duração , Proteínas do Tecido Nervoso , Receptores de AMPA , Animais , Potenciação de Longa Duração/fisiologia , Fosforilação , Hipocampo/metabolismo , Hipocampo/fisiologia , Receptores de AMPA/metabolismo , Masculino , Proteínas do Tecido Nervoso/metabolismo , Proteínas do Citoesqueleto/metabolismo , Comportamento Exploratório/fisiologia , Serina/metabolismo
13.
Chem Pharm Bull (Tokyo) ; 72(6): 559-565, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38880627

RESUMO

Biosynthetic intermediates of siderophore vibrioferrin (VF), O-citryl-L-serine, 2-aminoethyl citrate, and alanine-2-amidoethyl citrate were respectively synthesized as a mixture of stereoisomers. These compounds were used as substrates for enzyme reactions using recombinant PvsA, PvsB, and PvsE proteins as corresponding enzyme equivalents. The results of our study show that each enzyme reacts with a respective substrate and produces VF along the proposed biosynthetic pathway. Furthermore, the results of this study will contribute to the understanding of VF biosynthetic enzymes and may help in the development of antimicrobial drugs by inhibiting siderophore biosynthetic enzymes.


Assuntos
Sideróforos , Estereoisomerismo , Sideróforos/biossíntese , Sideróforos/química , Sideróforos/metabolismo , Especificidade por Substrato , Estrutura Molecular , Proteínas de Bactérias/metabolismo , Proteínas de Bactérias/química , Serina/biossíntese , Serina/química , Serina/metabolismo
14.
FASEB J ; 38(12): e23742, 2024 Jun 30.
Artigo em Inglês | MEDLINE | ID: mdl-38865203

RESUMO

Mitochondrial disease is a devastating genetic disorder, with mitochondrial myopathy, encephalopathy, lactic acidosis, and stroke-like episodes (MELAS) and m.3243A>G being the most common phenotype and genotype, respectively. The treatment for MELAS patients is still less effective. Here, we performed transcriptomic and proteomic analysis in muscle tissue of MELAS patients, and discovered that the expression of molecules involved in serine catabolism were significantly upregulated, and serine hydroxymethyltransferase 2 (SHMT2) increased significantly in both the mRNA and protein levels. The SHMT2 protein level was also increased in myoblasts with m.3243A>G mutation, which was transdifferentiated from patients derived fibroblasts, accompanying with the decreased nicotinamide adenine dinucleotide (NAD+)/reduced NAD+ (NADH) ratio and cell viability. After treating with SHMT2 inhibitor (SHIN1), the NAD+/NADH ratio and cell viability in MELAS myoblasts increased significantly. Taken together, our study indicates that enhanced serine catabolism plays an important role in the pathogenesis of MELAS and that SHIN1 can be a potential small molecule for the treatment of this disease.


Assuntos
Glicina Hidroximetiltransferase , Síndrome MELAS , Serina , Humanos , Síndrome MELAS/metabolismo , Síndrome MELAS/genética , Síndrome MELAS/patologia , Glicina Hidroximetiltransferase/metabolismo , Glicina Hidroximetiltransferase/genética , Serina/metabolismo , Mioblastos/metabolismo , NAD/metabolismo , Masculino , Proteômica/métodos , Feminino , Transcriptoma , Multiômica
15.
Int J Oral Sci ; 16(1): 44, 2024 Jun 17.
Artigo em Inglês | MEDLINE | ID: mdl-38886346

RESUMO

Metabolic heterogeneity plays a central role in sustaining uncontrolled cancer cell proliferation and shaping the tumor microenvironment (TME), which significantly compromises the clinical outcomes and responses to therapy in head and neck squamous cell carcinoma (HNSCC) patients. This highlights the urgent need to delineate the intrinsic heterogeneity and biological roles of metabolic vulnerabilities to advance precision oncology. The metabolic heterogeneity of malignant cells was identified using single-cell RNA sequencing (scRNA-seq) profiles and validated through bulk transcriptomes. Serine-glycine-one-carbon (SGOC) metabolism was screened out to be responsible for the aggressive malignant properties and poor prognosis in HNSCC patients. A 4-SGOC gene prognostic signature, constructed by LASSO-COX regression analysis, demonstrated good predictive performance for overall survival and therapeutic responses. Patients in the low-risk group exhibited greater infiltration of exhausted CD8+ T cells, and demonstrated better clinical outcomes after receiving immunotherapy and chemotherapy. Conversely, high-risk patients exhibited characteristics of cold tumors, with enhanced IMPDH1-mediated purine biosynthesis, resulting in poor responses to current therapies. IMPDH1 emerged as a potential therapeutic metabolic target. Treatment with IMPDH inhibitors effectively suppressed HNSCC cell proliferation and metastasis and induced apoptosis in vitro and in vivo by triggering GTP-exhaustion nucleolar stress. Our findings underscore the metabolic vulnerabilities of HNSCC in facilitating accurate patient stratification and individualized precise metabolic-targeted treatment.


Assuntos
Neoplasias de Cabeça e Pescoço , Serina , Análise de Célula Única , Carcinoma de Células Escamosas de Cabeça e Pescoço , Humanos , Prognóstico , Serina/metabolismo , Carcinoma de Células Escamosas de Cabeça e Pescoço/genética , Carcinoma de Células Escamosas de Cabeça e Pescoço/metabolismo , Neoplasias de Cabeça e Pescoço/genética , Neoplasias de Cabeça e Pescoço/metabolismo , Neoplasias de Cabeça e Pescoço/terapia , Glicina/metabolismo , Carbono/metabolismo , Transcriptoma , Microambiente Tumoral , Proliferação de Células , Linhagem Celular Tumoral , Animais
16.
Nat Commun ; 15(1): 4790, 2024 Jun 05.
Artigo em Inglês | MEDLINE | ID: mdl-38839752

RESUMO

Cancer cells are often addicted to serine synthesis to support growth. How serine synthesis is regulated in cancer is not well understood. We recently demonstrated protein arginine methyltransferase 1 (PRMT1) is upregulated in hepatocellular carcinoma (HCC) to methylate and activate phosphoglycerate dehydrogenase (PHGDH), thereby promoting serine synthesis. However, the mechanisms underlying PRMT1 upregulation and regulation of PRMT1-PHGDH axis remain unclear. Here, we show the E3 ubiquitin ligase F-box-only protein 7 (FBXO7) inhibits serine synthesis in HCC by binding PRMT1, inducing lysine 37 ubiquitination, and promoting proteosomal degradation of PRMT1. FBXO7-mediated PRMT1 downregulation cripples PHGDH arginine methylation and activation, resulting in impaired serine synthesis, accumulation of reactive oxygen species (ROS), and inhibition of HCC cell growth. Notably, FBXO7 is significantly downregulated in human HCC tissues, and inversely associated with PRMT1 protein and PHGDH methylation level. Overall, our study provides mechanistic insights into the regulation of cancer serine synthesis by FBXO7-PRMT1-PHGDH axis, and will facilitate the development of serine-targeting strategies for cancer therapy.


Assuntos
Carcinoma Hepatocelular , Proteínas F-Box , Neoplasias Hepáticas , Fosfoglicerato Desidrogenase , Proteína-Arginina N-Metiltransferases , Serina , Ubiquitinação , Proteína-Arginina N-Metiltransferases/metabolismo , Proteína-Arginina N-Metiltransferases/genética , Humanos , Carcinoma Hepatocelular/metabolismo , Carcinoma Hepatocelular/patologia , Carcinoma Hepatocelular/genética , Neoplasias Hepáticas/metabolismo , Neoplasias Hepáticas/patologia , Neoplasias Hepáticas/genética , Proteínas F-Box/metabolismo , Proteínas F-Box/genética , Serina/metabolismo , Serina/biossíntese , Fosfoglicerato Desidrogenase/metabolismo , Fosfoglicerato Desidrogenase/genética , Linhagem Celular Tumoral , Animais , Proteínas Repressoras/metabolismo , Proteínas Repressoras/genética , Camundongos , Proliferação de Células , Metilação , Regulação Neoplásica da Expressão Gênica , Camundongos Nus , Masculino , Células HEK293 , Feminino , Células Hep G2
17.
Amino Acids ; 56(1): 38, 2024 Jun 06.
Artigo em Inglês | MEDLINE | ID: mdl-38844708

RESUMO

Biomarkers that accurately reflect renal function are essential in management of chronic kidney diseases (CKD). However, in children, age/physique and medication often alter established renal biomarkers. We studied whether amino acid enantiomers in body fluids correlate with renal function and whether they are influenced by physique or steroid medication during development. We conducted a prospective study of children 2 to 18 years old with and without CKD. We analyzed associations of serine/asparagine enantiomers in body fluids with major biochemical parameters as well as physique. To study consequences of kidney dysfunction and steroids on serine/asparagine enantiomers, we generated juvenile mice with uninephrectomy, ischemic reperfusion injury, or dexamethasone treatment. We obtained samples from 27 children, of which 12 had CKD due to congenital (n = 7) and perinatal (n = 5) causes. Plasma D-asparagine and the D/L-serine ratio had robust, positive linear associations with serum creatinine and cystatin C, and detected CKD with high sensitivity and specificity, uninfluenced by body size or biochemical parameters. In the animal study, kidney dysfunction increased plasma D-asparagine and the D/L-serine ratio, but dexamethasone treatment did not. Thus, plasma D-asparagine and the D/L-serine ratio can be useful markers for renal function in children.


Assuntos
Asparagina , Biomarcadores , Insuficiência Renal Crônica , Serina , Criança , Animais , Humanos , Asparagina/sangue , Asparagina/metabolismo , Insuficiência Renal Crônica/sangue , Pré-Escolar , Serina/sangue , Camundongos , Masculino , Feminino , Adolescente , Biomarcadores/sangue , Estudos Prospectivos , Dexametasona , Estereoisomerismo , Creatinina/sangue , Rim/metabolismo
18.
Crit Rev Immunol ; 44(6): 37-47, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38848292

RESUMO

BACKGROUND: Estrogen receptor (ER) signaling plays an important role in the development and functional differentiation of the breast and participates in the process of breast cancer. Activated ER can affect various aspects of the cell's behavior, including proliferation, via modulating the expression of many downstream target genes. Phosphorylation is one of the activation pathways of ER. However, the relationship between estrogen receptor phosphorylation sites and breast development and carcinogenesis is not clear. METHODS: Using Crisper-Cas9 gene editing technology, we constructed ER S309A mutant mice. Using carmine staining of the mammary gland of mice at different developmental stages, we examined the breast development of ER S309A mice. Using hematoxylin-eosin (HE) staining of vaginal smears of mice at the same time for 5 consecutive days, we measured the vaginal epithelial keratinocytes. RESULTS: We established ER S309A mutant mice and observed breast defects in ER S309A mice. In addition, we observed decreased reproductive ability, and estrous cycle disorder in ER S309A mice. The number of vaginal epithelial keratino-cytes in the estrous cycle of ER S309A mice was decreased. CONCLUSION: These results suggest that the phosphorylation site of ER at Serine 309 is important for ER function and breast development.


Assuntos
Serina , Animais , Feminino , Camundongos , Fosforilação , Serina/metabolismo , Humanos , Receptores de Estrogênio/metabolismo , Receptores de Estrogênio/genética , Mama/crescimento & desenvolvimento , Mama/metabolismo , Neoplasias da Mama/genética , Neoplasias da Mama/metabolismo , Neoplasias da Mama/patologia , Glândulas Mamárias Animais/metabolismo , Glândulas Mamárias Animais/crescimento & desenvolvimento , Mutação
19.
J Clin Invest ; 134(13)2024 May 14.
Artigo em Inglês | MEDLINE | ID: mdl-38743486

RESUMO

Tumor cells are known to undergo considerable metabolic reprogramming to meet their unique demands and drive tumor growth. At the same time, this reprogramming may come at a cost with resultant metabolic vulnerabilities. The small molecule l-2-hydroxyglutarate (l-2HG) is elevated in the most common histology of renal cancer. Similarly to other oncometabolites, l-2HG has the potential to profoundly impact gene expression. Here, we demonstrate that l-2HG remodels amino acid metabolism in renal cancer cells through combined effects on histone methylation and RNA N6-methyladenosine. The combined effects of l-2HG result in a metabolic liability that renders tumors cells reliant on exogenous serine to support proliferation, redox homeostasis, and tumor growth. In concert with these data, high-l-2HG kidney cancers demonstrate reduced expression of multiple serine biosynthetic enzymes. Collectively, our data indicate that high-l-2HG renal tumors could be specifically targeted by strategies that limit serine availability to tumors.


Assuntos
Glutaratos , Neoplasias Renais , Neoplasias Renais/genética , Neoplasias Renais/metabolismo , Neoplasias Renais/patologia , Glutaratos/metabolismo , Humanos , Animais , Camundongos , Linhagem Celular Tumoral , Serina/metabolismo , Epigenoma , Transcriptoma , Histonas/metabolismo , Histonas/genética , Regulação Neoplásica da Expressão Gênica , RNA Neoplásico/genética , RNA Neoplásico/metabolismo , Carcinoma de Células Renais/genética , Carcinoma de Células Renais/metabolismo , Carcinoma de Células Renais/patologia , Epigênese Genética , Adenosina/análogos & derivados
20.
J Biol Chem ; 300(6): 107354, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38718862

RESUMO

The nucleocapsid protein (N) of SARS-CoV-2 is essential for virus replication, genome packaging, evading host immunity, and virus maturation. N is a multidomain protein composed of an independently folded monomeric N-terminal domain that is the primary site for RNA binding and a dimeric C-terminal domain that is essential for efficient phase separation and condensate formation with RNA. The domains are separated by a disordered Ser/Arg-rich region preceding a self-associating Leu-rich helix. Phosphorylation in the Ser/Arg region in infected cells decreases the viscosity of N:RNA condensates promoting viral replication and host immune evasion. The molecular level effect of phosphorylation, however, is missing from our current understanding. Using NMR spectroscopy and analytical ultracentrifugation, we show that phosphorylation destabilizes the self-associating Leu-rich helix 30 amino-acids distant from the phosphorylation site. NMR and gel shift assays demonstrate that RNA binding by the linker is dampened by phosphorylation, whereas RNA binding to the full-length protein is not significantly affected presumably due to retained strong interactions with the primary RNA-binding domain. Introducing a switchable self-associating domain to replace the Leu-rich helix confirms the importance of linker self-association to droplet formation and suggests that phosphorylation not only increases solubility of the positively charged elongated Ser/Arg region as observed in other RNA-binding proteins but can also inhibit self-association of the Leu-rich helix. These data highlight the effect of phosphorylation both at local sites and at a distant self-associating hydrophobic helix in regulating liquid-liquid phase separation of the entire protein.


Assuntos
Proteínas do Nucleocapsídeo de Coronavírus , SARS-CoV-2 , SARS-CoV-2/metabolismo , SARS-CoV-2/química , Fosforilação , Proteínas do Nucleocapsídeo de Coronavírus/metabolismo , Proteínas do Nucleocapsídeo de Coronavírus/química , Proteínas do Nucleocapsídeo de Coronavírus/genética , Humanos , RNA Viral/metabolismo , RNA Viral/química , RNA Viral/genética , Fosfoproteínas/metabolismo , Fosfoproteínas/química , Fosfoproteínas/genética , Serina/metabolismo , Serina/química , Proteínas do Nucleocapsídeo/metabolismo , Proteínas do Nucleocapsídeo/química , COVID-19/virologia , COVID-19/metabolismo , Arginina/química , Arginina/metabolismo , Ligação Proteica , Nucleocapsídeo/metabolismo , Nucleocapsídeo/química , Espectroscopia de Ressonância Magnética , Separação de Fases
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