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1.
Nat Commun ; 11(1): 4916, 2020 10 01.
Artigo em Inglês | MEDLINE | ID: mdl-33004803

RESUMO

Self-incompatibility (SI) is a breeding system that promotes cross-fertilization. In Brassica, pollen rejection is induced by a haplotype-specific interaction between pistil determinant SRK (S receptor kinase) and pollen determinant SP11 (S-locus Protein 11, also named SCR) from the S-locus. Although the structure of the B. rapa S9-SRK ectodomain (eSRK) and S9-SP11 complex has been determined, it remains unclear how SRK discriminates self- and nonself-SP11. Here, we uncover the detailed mechanism of self/nonself-discrimination in Brassica SI by determining the S8-eSRK-S8-SP11 crystal structure and performing molecular dynamics (MD) simulations. Comprehensive binding analysis of eSRK and SP11 structures reveals that the binding free energies are most stable for cognate eSRK-SP11 combinations. Residue-based contribution analysis suggests that the modes of eSRK-SP11 interactions differ between intra- and inter-subgroup (a group of phylogenetically neighboring haplotypes) combinations. Our data establish a model of self/nonself-discrimination in Brassica SI.


Assuntos
Brassica rapa/fisiologia , Melhoramento Vegetal , Proteínas de Plantas/metabolismo , Proteínas Quinases/metabolismo , Animais , Cristalografia , Flores/metabolismo , Haplótipos , Simulação de Dinâmica Molecular , Proteínas de Plantas/genética , Proteínas de Plantas/ultraestrutura , Pólen/metabolismo , Ligação Proteica/fisiologia , Domínios Proteicos/fisiologia , Proteínas Quinases/genética , Proteínas Quinases/ultraestrutura , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo , Proteínas Recombinantes/ultraestrutura , Células Sf9 , Spodoptera
2.
Nat Commun ; 11(1): 4479, 2020 09 08.
Artigo em Inglês | MEDLINE | ID: mdl-32900999

RESUMO

The giant protein titin is thought to be required for sarcomeric integrity in mature myocytes, but direct evidence for this hypothesis is limited. Here, we describe a mouse model in which Z-disc-anchored TTN is depleted in adult skeletal muscles. Inactivation of TTN causes sarcomere disassembly and Z-disc deformations, force impairment, myocyte de-stiffening, upregulation of TTN-binding mechanosensitive proteins and activation of protein quality-control pathways, concomitant with preferential loss of thick-filament proteins. Interestingly, expression of the myosin-bound Cronos-isoform of TTN, generated from an alternative promoter not affected by the targeting strategy, does not prevent deterioration of sarcomere formation and maintenance. Finally, we demonstrate that loss of Z-disc-anchored TTN recapitulates muscle remodeling in critical illness 'myosinopathy' patients, characterized by TTN-depletion and loss of thick filaments. We conclude that full-length TTN is required to integrate Z-disc and A-band proteins into the mature sarcomere, a function that is lost when TTN expression is pathologically lowered.


Assuntos
Fibras Musculares Esqueléticas/fisiologia , Proteínas Quinases/fisiologia , Sarcômeros/fisiologia , Animais , Fenômenos Biomecânicos , Modelos Animais de Doenças , Feminino , Humanos , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Microscopia Eletrônica de Transmissão , Força Muscular/fisiologia , Atrofia Muscular/etiologia , Atrofia Muscular/patologia , Atrofia Muscular/fisiopatologia , Doenças Musculares/patologia , Doenças Musculares/fisiopatologia , Miosinas/metabolismo , Proteínas Quinases/deficiência , Proteínas Quinases/genética , Sarcômeros/patologia , Ubiquitinação
3.
PLoS Pathog ; 16(8): e1008761, 2020 08.
Artigo em Inglês | MEDLINE | ID: mdl-32790758

RESUMO

The virus-bacterial synergism implicated in secondary bacterial infections caused by Streptococcus pneumoniae following infection with epidemic or pandemic influenza A virus (IAV) is well documented. However, the molecular mechanisms behind such synergism remain largely ill-defined. In pneumocytes infected with influenza A virus, subsequent infection with S. pneumoniae leads to enhanced pneumococcal intracellular survival. The pneumococcal two-component system SirRH appears essential for such enhanced survival. Through comparative transcriptomic analysis between the ΔsirR and wt strains, a list of 179 differentially expressed genes was defined. Among those, the clpL protein chaperone gene and the psaB Mn+2 transporter gene, which are involved in the stress response, are important in enhancing S. pneumoniae survival in influenza-infected cells. The ΔsirR, ΔclpL and ΔpsaB deletion mutants display increased susceptibility to acidic and oxidative stress and no enhancement of intracellular survival in IAV-infected pneumocyte cells. These results suggest that the SirRH two-component system senses IAV-induced stress conditions and controls adaptive responses that allow survival of S. pneumoniae in IAV-infected pneumocytes.


Assuntos
Proteínas de Bactérias/metabolismo , Coinfecção/mortalidade , Vírus da Influenza A/patogenicidade , Influenza Humana/mortalidade , Pulmão/patologia , Infecções Pneumocócicas/mortalidade , Streptococcus pneumoniae/patogenicidade , Proteínas de Bactérias/genética , Sobrevivência Celular , Coinfecção/epidemiologia , Humanos , Influenza Humana/microbiologia , Influenza Humana/patologia , Influenza Humana/virologia , Pulmão/microbiologia , Pulmão/virologia , Infecções Pneumocócicas/microbiologia , Infecções Pneumocócicas/patologia , Infecções Pneumocócicas/virologia , Proteínas Quinases/genética , Proteínas Quinases/metabolismo , Streptococcus pneumoniae/metabolismo , Estresse Fisiológico , Virulência
4.
Nat Commun ; 11(1): 4285, 2020 08 27.
Artigo em Inglês | MEDLINE | ID: mdl-32855390

RESUMO

Plant hormone cytokinins are perceived by a subfamily of sensor histidine kinases (HKs), which via a two-component phosphorelay cascade activate transcriptional responses in the nucleus. Subcellular localization of the receptors proposed the endoplasmic reticulum (ER) membrane as a principal cytokinin perception site, while study of cytokinin transport pointed to the plasma membrane (PM)-mediated cytokinin signalling. Here, by detailed monitoring of subcellular localizations of the fluorescently labelled natural cytokinin probe and the receptor ARABIDOPSIS HISTIDINE KINASE 4 (CRE1/AHK4) fused to GFP reporter, we show that pools of the ER-located cytokinin receptors can enter the secretory pathway and reach the PM in cells of the root apical meristem, and the cell plate of dividing meristematic cells. Brefeldin A (BFA) experiments revealed vesicular recycling of the receptor and its accumulation in BFA compartments. We provide a revised view on cytokinin signalling and the possibility of multiple sites of perception at PM and ER.


Assuntos
Proteínas de Arabidopsis/metabolismo , Membrana Celular/metabolismo , Citocininas/metabolismo , Retículo Endoplasmático/metabolismo , Corantes Fluorescentes/química , Proteínas Quinases/metabolismo , Receptores de Superfície Celular/metabolismo , Arabidopsis/citologia , Arabidopsis/genética , Arabidopsis/metabolismo , Proteínas de Arabidopsis/genética , Brefeldina A/farmacologia , Citocininas/química , Corantes Fluorescentes/metabolismo , Proteínas de Fluorescência Verde/genética , Proteínas de Fluorescência Verde/metabolismo , Meristema/citologia , Meristema/metabolismo , Plantas Geneticamente Modificadas , Proteínas Quinases/genética , Receptores de Superfície Celular/genética , Proteínas Recombinantes de Fusão/genética , Proteínas Recombinantes de Fusão/metabolismo , Transdução de Sinais/efeitos dos fármacos
5.
Mol Cell ; 79(3): 504-520.e9, 2020 08 06.
Artigo em Inglês | MEDLINE | ID: mdl-32707033

RESUMO

Protein kinases are essential for signal transduction and control of most cellular processes, including metabolism, membrane transport, motility, and cell cycle. Despite the critical role of kinases in cells and their strong association with diseases, good coverage of their interactions is available for only a fraction of the 535 human kinases. Here, we present a comprehensive mass-spectrometry-based analysis of a human kinase interaction network covering more than 300 kinases. The interaction dataset is a high-quality resource with more than 5,000 previously unreported interactions. We extensively characterized the obtained network and were able to identify previously described, as well as predict new, kinase functional associations, including those of the less well-studied kinases PIM3 and protein O-mannose kinase (POMK). Importantly, the presented interaction map is a valuable resource for assisting biomedical studies. We uncover dozens of kinase-disease associations spanning from genetic disorders to complex diseases, including cancer.


Assuntos
Redes Reguladoras de Genes , Doenças Genéticas Inatas/genética , Neoplasias/genética , Proteínas Quinases/genética , Proteínas Serina-Treonina Quinases/genética , Proteínas Proto-Oncogênicas/genética , Biologia Computacional/métodos , Conjuntos de Dados como Assunto , Regulação da Expressão Gênica , Ontologia Genética , Doenças Genéticas Inatas/enzimologia , Doenças Genéticas Inatas/patologia , Humanos , Redes e Vias Metabólicas/genética , Anotação de Sequência Molecular , Distrofias Musculares/enzimologia , Distrofias Musculares/genética , Distrofias Musculares/patologia , Neoplasias/enzimologia , Neoplasias/patologia , Doenças Neurodegenerativas/enzimologia , Doenças Neurodegenerativas/genética , Doenças Neurodegenerativas/patologia , Mapeamento de Interação de Proteínas/métodos , Proteínas Quinases/química , Proteínas Quinases/classificação , Proteínas Quinases/metabolismo , Proteínas Serina-Treonina Quinases/química , Proteínas Serina-Treonina Quinases/metabolismo , Proteínas Proto-Oncogênicas/química , Proteínas Proto-Oncogênicas/metabolismo , Transdução de Sinais
6.
PLoS Genet ; 16(7): e1008883, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-32609718

RESUMO

Plant steroid hormones brassinosteroids (BRs) regulate plant growth and development at many levels. While negative regulatory factors that inhibit development and are counteracted by BRs exist in the root meristem, these factors have not been characterized. The functions of UPB1 transcription factor in BR-regulated root growth have not been established, although its role in regulating root are well documented. Here, we found that BIN2 interacts with and phosphorylates the UPB1 transcription factor consequently promoting UPB1 stability and transcriptional activity. Genetic analysis revealed that UPB1 deficiency could partially recover the short-root phenotype of BR-deficient mutants. Expression of a mutated UPB1S37AS41A protein lacking a conserved BIN2 phosphorylation sites can rescue shorter root phenotype of bin2-1 mutant. In addition, UPB1 was repressed by BES1 at the transcriptional level. The paclobutrazol-resistant protein family (PRE2/3) interacts with UPB1 and inhibits its transcriptional activity to promote root meristem development, and BIN2-mediated phosphorylation of UPB1 suppresses its interaction with PRE2/3, and subsequently impairing root meristem development. Taken together, our data elucidate a molecular mechanism by which BR promotes root growth via inhibiting BIN2-UPB1 module.


Assuntos
Proteínas de Arabidopsis/genética , Arabidopsis/genética , Fatores de Transcrição Hélice-Alça-Hélice Básicos/genética , Brassinosteroides/metabolismo , Proteínas Quinases/genética , Arabidopsis/crescimento & desenvolvimento , Proteínas de Ligação a DNA/genética , Regulação da Expressão Gênica de Plantas/genética , Meristema/genética , Meristema/crescimento & desenvolvimento , Fosforilação , Raízes de Plantas/genética , Raízes de Plantas/crescimento & desenvolvimento , Plantas Geneticamente Modificadas/genética , Plantas Geneticamente Modificadas/crescimento & desenvolvimento , Transdução de Sinais/genética
7.
Nat Commun ; 11(1): 3563, 2020 07 16.
Artigo em Inglês | MEDLINE | ID: mdl-32678104

RESUMO

Rapidly increasing availability of genomic data and ensuing identification of disease associated mutations allows for an unbiased insight into genetic drivers of disease development. However, determination of molecular mechanisms by which individual genomic changes affect biochemical processes remains a major challenge. Here, we develop a multilayered proteomic workflow to explore how genetic lesions modulate the proteome and are translated into molecular phenotypes. Using this workflow we determine how expression of a panel of disease-associated mutations in the Dyrk2 protein kinase alter the composition, topology and activity of this kinase complex as well as the phosphoproteomic state of the cell. The data show that altered protein-protein interactions caused by the mutations are associated with topological changes and affected phosphorylation of known cancer driver proteins, thus linking Dyrk2 mutations with cancer-related biochemical processes. Overall, we discover multiple mutation-specific functionally relevant changes, thus highlighting the extensive plasticity of molecular responses to genetic lesions.


Assuntos
Neoplasias/genética , Neoplasias/patologia , Proteínas Quinases/genética , Proteômica/métodos , Linhagem Celular , Humanos , Espectrometria de Massas , Complexos Multiproteicos , Mutação , Proteínas de Neoplasias/metabolismo , Neoplasias/metabolismo , Fenótipo , Fosfoproteínas/metabolismo , Fosforilação , Conformação Proteica , Mapas de Interação de Proteínas , Proteínas Quinases/química , Proteínas Quinases/metabolismo , Proteínas Serina-Treonina Quinases/química , Proteínas Serina-Treonina Quinases/genética , Proteínas Serina-Treonina Quinases/metabolismo , Proteínas Tirosina Quinases/química , Proteínas Tirosina Quinases/genética , Proteínas Tirosina Quinases/metabolismo , Proteoma/metabolismo
8.
PLoS One ; 15(7): e0236950, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32730335

RESUMO

The use of natural products as feed additives in the poultry industry is increasing; however, most studies focus on performance and growth with little regard for determining mechanism. Our laboratory designed a chicken (Gallus gallus)-specific immunometabolic kinome peptide array. Using this tool to examine the active enzymes responsible for phosphorylation events (kinases) provides important information on host and cellular functions. The objective of this project was to determine if feeding a microencapsulated product comprised of a blend of organic acids and botanicals (AviPlus®P) impacts the intestinal kinome of broiler chickens (Gallus gallus). Day-of-hatch chicks were provided 0 or 500g/MT of the additive and jejunal and ileal segments collected for kinome analysis to determine the mode-of-action of the additive. Gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis was performed by uploading the statistically significant peptides to the Search Tool for the Retrieval of Interacting Genes database. As a whole, GO and KEGG analysis showed similar activities in the ileum and jejunum. However, there were a small number of KEGG pathways that were only activated in either the ileum or jejunum, but not both. Analysis of the adipocytokine and PI3K-AKT signaling pathways showed differences between ileal and jejunal activity that were controlled, in part, by AKT3. Additionally, cytokine/chemokine evaluation showed the ileum had higher IL1ß, IL6, IL10, TNFα, IFNγ, CXCL8, and CCL4 mRNA expression levels (P<0.05). As a whole, the data showed the addition of microencapsulated organic acids and botanicals to a broiler diet activated many of the same signaling pathways in the ileum and jejunum; however, distinctions were observed. Taken together, the findings of this study begin to define the mode-of-action that microencapsulated organic acids and botanicals have on two important intestinal segments responsible for nutrient digestion and absorption in chickens.


Assuntos
Ácidos/farmacologia , Dieta/veterinária , Íleo/metabolismo , Jejuno/metabolismo , Compostos Fitoquímicos/farmacologia , Proteínas Quinases/metabolismo , Ração Animal/análise , Animais , Galinhas , Perfilação da Expressão Gênica , Íleo/efeitos dos fármacos , Jejuno/efeitos dos fármacos , Plantas/química , Análise Serial de Proteínas , Proteínas Quinases/genética
9.
Nucleic Acids Res ; 48(15): 8360-8373, 2020 09 04.
Artigo em Inglês | MEDLINE | ID: mdl-32619236

RESUMO

Coordinated regulation of ribosomal RNA (rRNA) synthesis and ribosomal protein gene (RPG) transcription by eukaryotic RNA polymerases (RNAP) is a key requirement for growth control. Although evidence for balance between RNPI-dependent 35S rRNA production and RNAPII-mediated RPG transcription have been described, the molecular basis is still obscure. Here, we found that Rph1 modulates the transcription status of both rRNAs and RPGs in yeast. We show that Rph1 widely associates with RNAPI and RNAPII-transcribed genes. Deletion of RPH1 remarkably alleviates cell slow growth caused by TORC1 inhibition via derepression of rRNA and RPG transcription under nutrient stress conditions. Mechanistically, Rim15 kinase phosphorylates Rph1 upon rapamycin treatment. Phosphorylation-mimetic mutant of Rph1 exhibited more resistance to rapamycin treatment, decreased association with ribosome-related genes, and faster cell growth compared to the wild-type, indicating that Rph1 dissociation from chromatin ensures cell survival upon nutrient stress. Our results uncover the role of Rph1 in coordination of RNA polymerases-mediated transcription to control cell growth under nutrient stress conditions.


Assuntos
Proliferação de Células/genética , Histona Desmetilases/genética , Proteínas Quinases/genética , RNA Ribossômico/genética , Proteínas Repressoras/genética , Proteínas de Saccharomyces cerevisiae/genética , Cromatina/genética , Regulação Fúngica da Expressão Gênica/genética , Fosforilação , Proteínas Ribossômicas/genética , Ribossomos/genética , Ribossomos/metabolismo , Saccharomyces cerevisiae/genética , Transdução de Sinais/genética , Transcrição Genética
10.
PLoS One ; 15(7): e0235766, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32639993

RESUMO

High-grade serous ovarian carcinoma (HGSOC) remains the deadliest form of epithelial ovarian cancer and despite major efforts little improvement in overall survival has been achieved. Identification of recurring "driver" genetic lesions has the potential to enable design of novel therapies for cancer. Here, we report on a study to find such new therapeutic targets for HGSOC using exome-capture sequencing approach targeting all kinase genes in 127 patient samples. Consistent with previous reports, the most frequently mutated gene was TP53 (97% mutation frequency) followed by BRCA1 (10% mutation frequency). The average mutation frequency of the kinase genes mutated from our panel was 1.5%. Intriguingly, after BRCA1, JAK3 was the most frequently mutated gene (4% mutation frequency). We tested the transforming properties of JAK3 mutants using the Ba/F3 cell-based in vitro functional assay and identified a novel gain-of-function mutation in the kinase domain of JAK3 (p.T1022I). Importantly, p.T1022I JAK3 mutants displayed higher sensitivity to the JAK3-selective inhibitor Tofacitinib compared to controls. For independent validation, we re-sequenced the entire JAK3 coding sequence using tagged amplicon sequencing (TAm-Seq) in 463 HGSOCs resulting in an overall somatic mutation frequency of 1%. TAm-Seq screening of CDK12 in the same population revealed a 7% mutation frequency. Our data confirms that the frequency of mutations in kinase genes in HGSOC is low and provides accurate estimates for the frequency of JAK3 and CDK12 mutations in a large well characterized cohort. Although p.T1022I JAK3 mutations are rare, our functional validation shows that if detected they should be considered as potentially actionable for therapy. The observation of CDK12 mutations in 7% of HGSOC cases provides a strong rationale for routine somatic testing, although more functional and clinical characterization is required to understand which nonsynonymous mutations alterations are associated with homologous recombination deficiency.


Assuntos
Proteína BRCA1/genética , Cistadenocarcinoma Seroso/genética , Janus Quinase 3/genética , Mutação , Neoplasias Ovarianas/genética , Proteínas Quinases/genética , Proteína Supressora de Tumor p53/genética , Proteína BRCA1/metabolismo , Estudos de Casos e Controles , Estudos de Coortes , Cistadenocarcinoma Seroso/metabolismo , Cistadenocarcinoma Seroso/patologia , Feminino , Sequenciamento de Nucleotídeos em Larga Escala , Humanos , Janus Quinase 3/metabolismo , Neoplasias Ovarianas/metabolismo , Neoplasias Ovarianas/patologia , Proteínas Quinases/metabolismo , Proteína Supressora de Tumor p53/metabolismo
11.
Am Heart J ; 225: 108-119, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-32480058

RESUMO

INTRODUCTION: Biallelic damaging variants in ALPK3, encoding alpha-protein kinase 3, cause pediatric-onset cardiomyopathy with manifestations that are incompletely defined. METHODS AND RESULTS: We analyzed clinical manifestations of damaging biallelic ALPK3 variants in 19 pediatric patients, including nine previously published cases. Among these, 11 loss-of-function (LoF) variants, seven compound LoF and deleterious missense variants, and one homozygous deleterious missense variant were identified. Among 18 live-born patients, 8 exhibited neonatal dilated cardiomyopathy (44.4%; 95% CI: 21.5%-69.2%) that subsequently transitioned into ventricular hypertrophy. The majority of patients had extracardiac phenotypes, including contractures, scoliosis, cleft palate, and facial dysmorphisms. We observed no association between variant type or location, disease severity, and/or extracardiac manifestations. Myocardial histopathology showed focal cardiomyocyte hypertrophy, subendocardial fibroelastosis in patients under 4 years of age, and myofibrillar disarray in adults. Rare heterozygous ALPK3 variants were also assessed in adult-onset cardiomyopathy patients. Among 1548 Dutch patients referred for initial genetic analyses, we identified 39 individuals with rare heterozygous ALPK3 variants (2.5%; 95% CI: 1.8%-3.4%), including 26 missense and 10 LoF variants. Among 149 U.S. patients without pathogenic variants in 83 cardiomyopathy-related genes, we identified six missense and nine LoF ALPK3 variants (10.1%; 95% CI: 5.7%-16.1%). LoF ALPK3 variants were increased in comparison to matched controls (Dutch cohort, P = 1.6×10-5; U.S. cohort, P = 2.2×10-13). CONCLUSION: Biallelic damaging ALPK3 variants cause pediatric cardiomyopathy manifested by DCM transitioning to hypertrophy, often with poor contractile function. Additional extracardiac features occur in most patients, including musculoskeletal abnormalities and cleft palate. Heterozygous LoF ALPK3 variants are enriched in adults with cardiomyopathy and may contribute to their cardiomyopathy. Adults with ALPK3 LoF variants therefore warrant evaluations for cardiomyopathy.


Assuntos
Cardiomiopatias/genética , Heterozigoto , Mutação com Perda de Função , Proteínas Musculares/genética , Mutação de Sentido Incorreto , Proteínas Quinases/genética , Anormalidades Múltiplas/genética , Adulto , Idade de Início , Cardiomiopatias/diagnóstico por imagem , Cardiomiopatias/fisiopatologia , Cardiomiopatia Dilatada/genética , Cardiomiopatia Hipertrófica/genética , Criança , Pré-Escolar , Cromossomos Humanos Par 15/genética , Ecocardiografia , Eletrocardiografia , Humanos , Lactente , Fenótipo
12.
Gene ; 756: 144917, 2020 Sep 25.
Artigo em Inglês | MEDLINE | ID: mdl-32590104

RESUMO

The self-incompatibility system of Corylus is a sporophytic type that is phenotypically similar to that of Brassica. While the molecular mechanism of sporophytic self-incompatibility (SSI) has been investigated extensively in Brassica (Brassicaceae), little is known about the corresponding mechanism in Corylus (Betulaceae). Here, we discuss the SSI mechanism with respect to S-locus receptor kinase (SRK) gene homologs. To obtain two SRK candidate unigenes, we compared all of the unigenes in a transcriptional protein database from our previous study with BnSRK-1 (AB270767) using BLASTX with a cutoff e-value of 10-5. We then cloned the full-length cDNA of ChaSRK1 and ChaSRK2 genes from Ping'ou hybrid hazelnut (Corylus heterophylla × Corylus avellana) using RACE techniques. Bioinformatics approaches were used to analyze the cDNA sequences, protein sequences, and domains of the encoded proteins. The full-length ChaSRK1 cDNA was 2883 base pairs (bp) with a coding sequence (CDS) of 2,547 bp encoding 849 amino acid residues. The full-length ChaSRK2 cDNA was 2,693 bp, with a CDS of 2,433 bp encoding 811 amino acids. The ChaSRK1/2 proteins contained an S-domain (extracellular domain), a transmembrane domain, a Ser/Thr protein kinase active site (kinase domain), and DUF3660 and/or DUF3403 domains. The lengths of 18 partial SRK homologs ranged from 1347 to 1451 bp, and they contained the same structural domains as ChaSRK1 and ChaSRK2. Phylogenetic analysis revealed that all SRK homologs could be divided into two categories that were similar to the classification of SRKs in Brassica. The expression patterns of ChaSRK1 and ChaSRK2 differed: ChaSRK2 was predominantly expressed in mature stigmatic styles, while ChaSRK1 was expressed in other tissues with the highest in the root tips of Corylus. Using dual-color fluorescence in situ hybridization, ChaSRK1/2 expression was found to be localized in papillar cells. Collectively, these results revealed that SRKs from Corylus had similar characteristics to SRKs from Brassica. We therefore speculated that the SSI mechanism in Corylus might be more similar to the Brassica mechanism than to other SSI types.


Assuntos
Corylus/enzimologia , Corylus/fisiologia , Proteínas de Plantas/genética , Proteínas Quinases/genética , Autoincompatibilidade em Angiospermas , Sequência de Bases , Brassica/fisiologia , Clonagem Molecular , Corylus/genética , Filogenia , Alinhamento de Sequência , Transcriptoma
13.
PLoS Genet ; 16(6): e1008840, 2020 06.
Artigo em Inglês | MEDLINE | ID: mdl-32579556

RESUMO

The S. cerevisiae ISR1 gene encodes a putative kinase with no ascribed function. Here, we show that Isr1 acts as a negative regulator of the highly-conserved hexosamine biosynthesis pathway (HBP), which converts glucose into uridine diphosphate N-acetylglucosamine (UDP-GlcNAc), the carbohydrate precursor to protein glycosylation, GPI-anchor formation, and chitin biosynthesis. Overexpression of ISR1 is lethal and, at lower levels, causes sensitivity to tunicamycin and resistance to calcofluor white, implying impaired protein glycosylation and reduced chitin deposition. Gfa1 is the first enzyme in the HBP and is conserved from bacteria and yeast to humans. The lethality caused by ISR1 overexpression is rescued by co-overexpression of GFA1 or exogenous glucosamine, which bypasses GFA1's essential function. Gfa1 is phosphorylated in an Isr1-dependent fashion and mutation of Isr1-dependent sites ameliorates the lethality associated with ISR1 overexpression. Isr1 contains a phosphodegron that is phosphorylated by Pho85 and subsequently ubiquitinated by the SCF-Cdc4 complex, largely confining Isr1 protein levels to the time of bud emergence. Mutation of this phosphodegron stabilizes Isr1 and recapitulates the overexpression phenotypes. As Pho85 is a cell cycle and nutrient responsive kinase, this tight regulation of Isr1 may serve to dynamically regulate flux through the HBP and modulate how the cell's energy resources are converted into structural carbohydrates in response to changing cellular needs.


Assuntos
Glutamina-Frutose-6-Fosfato Transaminase (Isomerizante)/metabolismo , Hexosaminas/biossíntese , Proteínas Quinases/metabolismo , Proteínas de Saccharomyces cerevisiae/metabolismo , Saccharomyces cerevisiae/enzimologia , Metabolismo Energético , Glucose/metabolismo , Glutamina-Frutose-6-Fosfato Transaminase (Isomerizante)/genética , Mutação , Fosforilação , Proteínas Quinases/genética , Processamento de Proteína Pós-Traducional , Estabilidade Proteica , Proteínas de Saccharomyces cerevisiae/genética , Uridina Difosfato N-Acetilglicosamina/metabolismo
14.
Proc Natl Acad Sci U S A ; 117(25): 14433-14443, 2020 06 23.
Artigo em Inglês | MEDLINE | ID: mdl-32513747

RESUMO

During infection, the bacterial pathogen Legionella pneumophila manipulates a variety of host cell signaling pathways, including the Hippo pathway which controls cell proliferation and differentiation in eukaryotes. Our previous studies revealed that L. pneumophila encodes the effector kinase LegK7 which phosphorylates MOB1A, a highly conserved scaffold protein of the Hippo pathway. Here, we show that MOB1A, in addition to being a substrate of LegK7, also functions as an allosteric activator of its kinase activity. A crystallographic analysis of the LegK7-MOB1A complex revealed that the N-terminal half of LegK7 is structurally similar to eukaryotic protein kinases, and that MOB1A directly binds to the LegK7 kinase domain. Substitution of interface residues critical for complex formation abrogated allosteric activation of LegK7 both in vitro and within cells and diminished MOB1A phosphorylation. Importantly, the N-terminal extension (NTE) of MOB1A not only regulated complex formation with LegK7 but also served as a docking site for downstream substrates such as the transcriptional coregulator YAP1. Deletion of the NTE from MOB1A or addition of NTE peptides as binding competitors attenuated YAP1 recruitment to and phosphorylation by LegK7. By providing mechanistic insight into the formation and regulation of the LegK7-MOB1A complex, our study unravels a sophisticated molecular mimicry strategy that is used by L. pneumophila to take control of the host cell Hippo pathway.


Assuntos
Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Proteínas de Bactérias/metabolismo , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , Legionella pneumophila/metabolismo , Proteínas Quinases/metabolismo , Proteínas Adaptadoras de Transdução de Sinal/genética , Regulação Alostérica , Animais , Proteínas de Bactérias/genética , Proteínas de Ciclo Celular/metabolismo , Células HEK293 , Interações Hospedeiro-Patógeno , Humanos , Peptídeos e Proteínas de Sinalização Intracelular/genética , Legionella pneumophila/patogenicidade , Doença dos Legionários/microbiologia , Doença dos Legionários/patologia , Macrófagos Alveolares/microbiologia , Macrófagos Alveolares/patologia , Camundongos , Simulação de Dinâmica Molecular , Mimetismo Molecular , Fosforilação , Ligação Proteica , Proteínas Quinases/genética , Células RAW 264.7 , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo , Transdução de Sinais , Fatores de Transcrição/metabolismo
15.
Nat Commun ; 11(1): 3150, 2020 06 19.
Artigo em Inglês | MEDLINE | ID: mdl-32561755

RESUMO

MLKL is the essential effector of necroptosis, a form of programmed lytic cell death. We have isolated a mouse strain with a single missense mutation, MlklD139V, that alters the two-helix 'brace' that connects the killer four-helix bundle and regulatory pseudokinase domains. This confers constitutive, RIPK3 independent killing activity to MLKL. Homozygous mutant mice develop lethal postnatal inflammation of the salivary glands and mediastinum. The normal embryonic development of MlklD139V homozygotes until birth, and the absence of any overt phenotype in heterozygotes provides important in vivo precedent for the capacity of cells to clear activated MLKL. These observations offer an important insight into the potential disease-modulating roles of three common human MLKL polymorphisms that encode amino acid substitutions within or adjacent to the brace region. Compound heterozygosity of these variants is found at up to 12-fold the expected frequency in patients that suffer from a pediatric autoinflammatory disease, chronic recurrent multifocal osteomyelitis (CRMO).


Assuntos
Células-Tronco Hematopoéticas/metabolismo , Sistema Hematopoético/patologia , Necroptose/genética , Proteínas Quinases/genética , Animais , Animais Recém-Nascidos , Doenças Hereditárias Autoinflamatórias , Humanos , Inflamação/genética , Camundongos , Mutação de Sentido Incorreto , Osteomielite/genética , Proteínas Quinases/metabolismo
16.
Nat Commun ; 11(1): 3133, 2020 06 19.
Artigo em Inglês | MEDLINE | ID: mdl-32561764

RESUMO

Proximity proteomics has greatly advanced the analysis of native protein complexes and subcellular structures in culture, but has not been amenable to study development and disease in vivo. Here, we have generated a knock-in mouse with the biotin ligase (BioID) inserted at titin's Z-disc region to identify protein networks that connect the sarcomere to signal transduction and metabolism. Our census of the sarcomeric proteome from neonatal to adult heart and quadriceps reveals how perinatal signaling, protein homeostasis and the shift to adult energy metabolism shape the properties of striated muscle cells. Mapping biotinylation sites to sarcomere structures refines our understanding of myofilament dynamics and supports the hypothesis that myosin filaments penetrate Z-discs to dampen contraction. Extending this proof of concept study to BioID fusion proteins generated with Crispr/CAS9 in animal models recapitulating human pathology will facilitate the future analysis of molecular machines and signaling hubs in physiological, pharmacological, and disease context.


Assuntos
Carbono-Nitrogênio Ligases/genética , Proteínas de Escherichia coli/genética , Proteínas Quinases/metabolismo , Proteoma/metabolismo , Proteômica/métodos , Proteínas Repressoras/genética , Sarcômeros/metabolismo , Animais , Animais Recém-Nascidos , Biotinilação/genética , Feminino , Técnicas de Introdução de Genes , Masculino , Redes e Vias Metabólicas , Camundongos Transgênicos , Modelos Animais , Miocárdio/citologia , Miocárdio/metabolismo , Estudo de Prova de Conceito , Mapas de Interação de Proteínas/fisiologia , Proteínas Quinases/genética , Proteostase/fisiologia , Músculo Quadríceps/citologia , Músculo Quadríceps/metabolismo , Sarcômeros/genética , Transdução de Sinais/fisiologia , Relação Estrutura-Atividade
17.
PLoS One ; 15(6): e0234011, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32484825

RESUMO

The tomato AGC protein kinase Adi3 is a Ser/Thr kinase that functions as a negative regulator of programmed cell death through cell death suppression (CDS) activity in the nucleus. In this study, to understand the mechanism of Adi3 CDS, peptide microarrays containing random Ser- and Thr-peptide phosphorylation substrates were used to screen for downstream phosphorylation substrates. In the microarray phosphorylation assay, Adi3 showed promiscuous kinase activity more toward Ser-peptides compared to Thr-peptides, and a preference for aromatic and cyclic amino acids on both Ser- and Thr-peptides was seen. The 63 highest phosphorylated peptide sequences from the Ser-peptide microarray were selected as queries for a BLAST search against the tomato proteome. As a result, 294 candidate nuclear Adi3 substrates were selected and categorized based on their functions. Many of these proteins were classified as DNA/RNA polymerases or regulators involved in transcription and translation events. The list of potential Adi3 substrates was narrowed to eleven and four candidates were tested for phosphorylation by Adi3. Two of these candidates, RNA polymerase II 2nd largest subunit (RPB2) and the pathogen defense related transcription factor Pti5, were confirmed as Adi3 phosphorylation substrates by in vitro kinase assays. Using a mutational approach two residues, Thr675 and Thr676, were identified as Adi3 phosphorylation sites on RPB2. This study provides the foundation for understanding Adi3 CDS mechanisms in the nucleus as well as other cellular functions.


Assuntos
Morte Celular/genética , Peptídeos/genética , Células Vegetais/metabolismo , Proteínas de Plantas/genética , Sequência de Aminoácidos , Núcleo Celular/genética , Lycopersicon esculentum/genética , Lycopersicon esculentum/metabolismo , Análise em Microsséries , Mutação/genética , Fosforilação/genética , Proteínas Quinases/genética
18.
Life Sci ; 256: 117923, 2020 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-32522567

RESUMO

AIMS: Liver kinase B1 (LKB1) deficiency is associated with reduced expression of programmed death ligand 1 (PD-L1) and inferior clinical outcomes of PD-1/PD-L1 blockade in non-small cell lung cancer (NSCLC). This study aimed to investigate the mechanism by which LKB1 regulates PD-L1 expression and its role in programmed death 1 (PD-1) blockade therapy in NSCLC. MAIN METHODS: The impact of LKB1 on PD-L1 was assessed by western blot, qRT-PCR and immunohistochemistry in NSCLC. Activators/inhibitors of AMPK and NRF2 were applied to explore the mechanisms underlying the regulation of PD-L1 by LKB1. Efficiency of combined application of metformin and PD-1 blockade was evaluated in immunocompetent C57BL/6 mice. KEY FINDINGS: A remarkable positive correlation between LKB1 and PD-L1 expression was demonstrated in NSCLC tissues. Knockdown of LKB1 decreased PD-L1 in TC-1 cells, whereas overexpression of LKB1 increased PD-L1 in A549 cells. We further characterized that AMPK mediated the upregulation of PD-L1 by LKB1. Inhibition of AMPK or NRF2 markedly reduced PD-L1 in LKB1-intact NSCLC cells. In contrast, activation of AMPK or NRF2 reversed PD-L1 expression in LKB1-deficient NSCLC cells. Combined administration of metformin and anti-PD-1 antibody efficiently inhibited the growth of LKB1-intact tumors, whereas no obvious suppression was observed in LKB1-deficient tumors. SIGNIFICANCE: These findings demonstrated that LKB1 upregulates PD-L1 expression in NSCLC by activating the AMPK and KEAP1/NRF2 signaling. Activation of LKB1-AMPK with metformin improves the therapeutic effect of PD-1 blockade in NSCLC with wild-type LKB1.


Assuntos
Anticorpos Monoclonais Humanizados/farmacologia , Antineoplásicos/farmacologia , Carcinoma Pulmonar de Células não Pequenas/metabolismo , Neoplasias Pulmonares/metabolismo , Metformina/farmacologia , Receptor de Morte Celular Programada 1/metabolismo , Proteínas Serina-Treonina Quinases/metabolismo , Células A549 , Animais , Anticorpos Monoclonais Humanizados/metabolismo , Antineoplásicos/metabolismo , Protocolos de Quimioterapia Combinada Antineoplásica , Regulação da Expressão Gênica , Técnicas de Silenciamento de Genes , Humanos , Proteína 1 Associada a ECH Semelhante a Kelch/metabolismo , Metformina/metabolismo , Camundongos Endogâmicos C57BL , Fator 2 Relacionado a NF-E2/genética , Fator 2 Relacionado a NF-E2/metabolismo , Proteínas Quinases/genética , Proteínas Quinases/metabolismo , Transdução de Sinais , Ativação Transcricional , Regulação para Cima
19.
Proc Natl Acad Sci U S A ; 117(20): 10935-10945, 2020 05 19.
Artigo em Inglês | MEDLINE | ID: mdl-32355000

RESUMO

The circadian clock in eukaryotes controls transcriptional and posttranscriptional events, including regulation of the levels and phosphorylation state of translation factors. However, the mechanisms underlying clock control of translation initiation, and the impact of this potential regulation on rhythmic protein synthesis, were not known. We show that inhibitory phosphorylation of eIF2α (P-eIF2α), a conserved translation initiation factor, is clock controlled in Neurospora crassa, peaking during the subjective day. Cycling P-eIF2α levels required rhythmic activation of the eIF2α kinase CPC-3 (the homolog of yeast and mammalian GCN2), and rhythmic activation of CPC-3 was abolished under conditions in which the levels of charged tRNAs were altered. Clock-controlled accumulation of P-eIF2α led to reduced translation during the day in vitro and was necessary for the rhythmic synthesis of select proteins in vivo. Finally, loss of rhythmic P-eIF2α levels led to reduced linear growth rates, supporting the idea that partitioning translation to specific times of day provides a growth advantage to the organism. Together, these results reveal a fundamental mechanism by which the clock regulates rhythmic protein production, and provide key insights into how rhythmic translation, cellular energy, stress, and nutrient metabolism are linked through the levels of charged versus uncharged tRNAs.


Assuntos
Relógios Circadianos/fisiologia , Fator de Iniciação 2 em Eucariotos/metabolismo , Processamento de Proteína Pós-Traducional/fisiologia , Animais , Ritmo Circadiano , Fator de Iniciação 2 em Eucariotos/genética , Proteínas Fúngicas/genética , Proteínas Fúngicas/metabolismo , Regulação Fúngica da Expressão Gênica , Neurospora crassa/crescimento & desenvolvimento , Neurospora crassa/metabolismo , Fosforilação , Proteínas Quinases/genética , Proteínas Quinases/metabolismo , eIF-2 Quinase/metabolismo
20.
Nucleic Acids Res ; 48(12): 6547-6562, 2020 07 09.
Artigo em Inglês | MEDLINE | ID: mdl-32453397

RESUMO

Heme is a multifaceted molecule. While serving as a prosthetic group for many important proteins, elevated levels are toxic to cells. The complexity of this stimulus has shaped bacterial network evolution. However, only a small number of targets controlled by heme-responsive regulators have been described to date. Here, we performed chromatin affinity purification and sequencing to provide genome-wide insights into in vivo promoter occupancy of HrrA, the response regulator of the heme-regulated two-component system HrrSA of Corynebacterium glutamicum. Time-resolved profiling revealed dynamic binding of HrrA to more than 200 different genomic targets encoding proteins associated with heme biosynthesis, the respiratory chain, oxidative stress response and cell envelope remodeling. By repression of the extracytoplasmic function sigma factor sigC, which activates the cydABCD operon, HrrA prioritizes the expression of genes encoding the cytochrome bc1-aa3 supercomplex. This is also reflected by a significantly decreased activity of the cytochrome aa3 oxidase in the ΔhrrA mutant. Furthermore, our data reveal that HrrA also integrates the response to heme-induced oxidative stress by activating katA encoding the catalase. These data provide detailed insights in the systemic strategy that bacteria have evolved to respond to the versatile signaling molecule heme.


Assuntos
Proteínas de Bactérias/metabolismo , Complexo de Proteínas da Cadeia de Transporte de Elétrons/genética , Regulação Bacteriana da Expressão Gênica , Heme/metabolismo , Proteínas Quinases/metabolismo , Proteínas de Bactérias/genética , Corynebacterium glutamicum/genética , Corynebacterium glutamicum/metabolismo , Complexo de Proteínas da Cadeia de Transporte de Elétrons/metabolismo , Óperon , Regiões Promotoras Genéticas , Proteínas Quinases/genética , Fator sigma/metabolismo
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