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1.
bioRxiv ; 2024 Apr 25.
Artículo en Inglés | MEDLINE | ID: mdl-38712050

RESUMEN

Chlamydia trachomatis (C.t.), the leading cause of bacterial sexually transmitted infections, employs a type III secretion system (T3SS) to translocate two classes of effectors, inclusion membrane proteins and conventional T3SS (cT3SS) effectors, into the host cell to counter host defense mechanisms. Here we employed three assays to directly evaluate secretion during infection, validating secretion for 23 cT3SS effectors. As bioinformatic analyses have been largely unrevealing, we conducted affinity purification-mass spectrometry to identify host targets and gain insights into the functions of these effectors, identifying high confidence interacting partners for 21 cT3SS effectors. We demonstrate that CebN localizes to the nuclear envelope in infected and bystander cells where it interacts with multiple nucleoporins and Rae1, blocking STAT1 nuclear import following IFN-γ stimulation. By building a cT3SS effector-host interactome, we have identified novel pathways that are targeted during bacterial infection and have begun to address how C.t. effectors combat cell autonomous immunity.

2.
Int J Mol Sci ; 24(7)2023 Mar 26.
Artículo en Inglés | MEDLINE | ID: mdl-37047232

RESUMEN

Increased expression of NUSAP1 has been identified as a robust prognostic biomarker in prostate cancer and other malignancies. We have previously shown that NUSAP1 is positively regulated by E2F1 and promotes cancer invasion and metastasis. To further understand the biological function of NUSAP1, we used affinity purification and mass spectrometry proteomic analysis to identify NUSAP1 interactors. We identified 85 unique proteins in the NUSAP1 interactome, including ILF2, DHX9, and other RNA-binding proteins. Using proteomic approaches, we uncovered a function for NUSAP1 in maintaining R-loops and in DNA damage response through its interaction with ILF2. Co-immunoprecipitation and colocalization using confocal microscopy verified the interactions of NUSAP1 with ILF2 and DHX9, and RNA/DNA hybrids. We showed that the microtubule and charged helical domains of NUSAP1 were necessary for the protein-protein interactions. Depletion of ILF2 alone further increased camptothecin-induced R-loop accumulation and DNA damage, and NUSAP1 depletion abolished this effect. In human prostate adenocarcinoma, NUSAP1 and ILF2 mRNA expression levels are positively correlated, elevated, and associated with poor clinical outcomes. Our study identifies a novel role for NUSAP1 in regulating R-loop formation and accumulation in response to DNA damage through its interactions with ILF2 and hence provides a potential therapeutic target.


Asunto(s)
Neoplasias de la Próstata , Estructuras R-Loop , Humanos , Masculino , Daño del ADN , Proteínas Asociadas a Microtúbulos/metabolismo , Proteína del Factor Nuclear 45/genética , Proteína del Factor Nuclear 45/metabolismo , Neoplasias de la Próstata/genética , Neoplasias de la Próstata/patología , Proteómica
3.
Mol Cell Proteomics ; 22(2): 100496, 2023 02.
Artículo en Inglés | MEDLINE | ID: mdl-36640924

RESUMEN

Transcriptional enhanced associate domain family members 1 to 4 (TEADs) are a family of four transcription factors and the major transcriptional effectors of the Hippo pathway. In order to activate transcription, TEADs rely on interactions with other proteins, such as the transcriptional effectors Yes-associated protein and transcriptional co-activator with PDZ-binding motif. Nuclear protein interactions involving TEADs influence the transcriptional regulation of genes involved in cell growth, tissue homeostasis, and tumorigenesis. Clearly, protein interactions for TEADs are functionally important, but the full repertoire of TEAD interaction partners remains unknown. Here, we employed an affinity purification mass spectrometry approach to identify nuclear interacting partners of TEADs. We performed affinity purification mass spectrometry experiment in parallel in two different cell types and compared a wildtype TEAD bait protein to a nuclear localization sequence mutant that does not localize to the nucleus. We quantified the results using SAINT analysis and found a significant enrichment of proteins linked to DNA damage including X-ray repair cross-complementing protein 5 (XRCC5), X-ray repair cross-complementing protein 6 (XRCC6), poly(ADP-ribose) polymerase 1 (PARP1), and Rap1-interacting factor 1 (RIF1). In cellular assays, we found that TEADs co-localize with DNA damage-induced nuclear foci marked by histone H2AX phosphorylated on S139 (γH2AX) and Rap1-interacting factor 1. We also found that depletion of TEAD proteins makes cells more susceptible to DNA damage by various agents and that depletion of TEADs promotes genomic instability. Additionally, depleting TEADs dampens the efficiency of DNA double-stranded break repair in reporter assays. Our results connect TEADs to DNA damage response processes, positioning DNA damage as an important avenue for further research of TEAD proteins.


Asunto(s)
Daño del ADN , Reparación del ADN , Factores de Transcripción de Dominio TEA , Humanos , Carcinogénesis/metabolismo , Reparación del ADN/fisiología , Proteínas de Unión al ADN/metabolismo , Factores de Transcripción/metabolismo , Factores de Transcripción de Dominio TEA/metabolismo
4.
Mol Cell Proteomics ; 22(1): 100477, 2023 01.
Artículo en Inglés | MEDLINE | ID: mdl-36496144

RESUMEN

Liquid chromatography coupled with bottom-up mass spectrometry (LC-MS/MS)-based proteomics is increasingly used to detect changes in posttranslational modifications (PTMs) in samples from different conditions. Analysis of data from such experiments faces numerous statistical challenges. These include the low abundance of modified proteoforms, the small number of observed peptides that span modification sites, and confounding between changes in the abundance of PTM and the overall changes in the protein abundance. Therefore, statistical approaches for detecting differential PTM abundance must integrate all the available information pertaining to a PTM site and consider all the relevant sources of confounding and variation. In this manuscript, we propose such a statistical framework, which is versatile, accurate, and leads to reproducible results. The framework requires an experimental design, which quantifies, for each sample, both peptides with PTMs and peptides from the same proteins with no modification sites. The proposed framework supports both label-free and tandem mass tag-based LC-MS/MS acquisitions. The statistical methodology separately summarizes the abundances of peptides with and without the modification sites, by fitting separate linear mixed effects models appropriate for the experimental design. Next, model-based inferences regarding the PTM and the protein-level abundances are combined to account for the confounding between these two sources. Evaluations on computer simulations, a spike-in experiment with known ground truth, and three biological experiments with different organisms, modification types, and data acquisition types demonstrate the improved fold change estimation and detection of differential PTM abundance, as compared to currently used approaches. The proposed framework is implemented in the free and open-source R/Bioconductor package MSstatsPTM.


Asunto(s)
Proteómica , Espectrometría de Masas en Tándem , Proteómica/métodos , Cromatografía Liquida , Procesamiento Proteico-Postraduccional , Proteínas , Péptidos/química
5.
Cell Rep ; 39(2): 110690, 2022 04 12.
Artículo en Inglés | MEDLINE | ID: mdl-35417684

RESUMEN

Viruses must effectively remodel host cellular pathways to replicate and evade immune defenses, and they must do so with limited genomic coding capacity. Targeting post-translational modification (PTM) pathways provides a mechanism by which viruses can broadly and rapidly transform a hostile host environment into a hospitable one. We use mass spectrometry-based proteomics to quantify changes in protein abundance and two PTM types-phosphorylation and ubiquitination-in response to HIV-1 infection with viruses harboring targeted deletions of a subset of HIV-1 genes. PTM analysis reveals a requirement for Aurora kinase activity in HIV-1 infection and identified putative substrates of a phosphatase that is degraded during infection. Finally, we demonstrate that the HIV-1 Vpr protein inhibits histone H1 ubiquitination, leading to defects in DNA repair.


Asunto(s)
Infecciones por VIH , Seropositividad para VIH , VIH-1 , VIH-1/genética , Humanos , Procesamiento Proteico-Postraduccional , Proteómica , Ubiquitinación
6.
J Cell Biol ; 221(4)2022 04 04.
Artículo en Inglés | MEDLINE | ID: mdl-35266954

RESUMEN

Missense mutations in leucine-rich repeat kinase 2 (LRRK2) are the most common cause of familial Parkinson's disease (PD); however, pathways regulating LRRK2 subcellular localization, function, and turnover are not fully defined. We performed quantitative mass spectrometry-based interactome studies to identify 48 novel LRRK2 interactors, including the microtubule-associated E3 ubiquitin ligase TRIM1 (tripartite motif family 1). TRIM1 recruits LRRK2 to the microtubule cytoskeleton for ubiquitination and proteasomal degradation by binding LRRK2911-919, a nine amino acid segment within a flexible interdomain region (LRRK2853-981), which we designate the "regulatory loop" (RL). Phosphorylation of LRRK2 Ser910/Ser935 within LRRK2 RL influences LRRK2's association with cytoplasmic 14-3-3 versus microtubule-bound TRIM1. Association with TRIM1 modulates LRRK2's interaction with Rab29 and prevents upregulation of LRRK2 kinase activity by Rab29 in an E3-ligase-dependent manner. Finally, TRIM1 rescues neurite outgrowth deficits caused by PD-driving mutant LRRK2 G2019S. Our data suggest that TRIM1 is a critical regulator of LRRK2, controlling its degradation, localization, binding partners, kinase activity, and cytotoxicity.


Asunto(s)
Proteína 2 Quinasa Serina-Treonina Rica en Repeticiones de Leucina , Enfermedad de Parkinson , Proteínas Serina-Treonina Quinasas , Proteínas de Motivos Tripartitos , Citoesqueleto , Humanos , Proteína 2 Quinasa Serina-Treonina Rica en Repeticiones de Leucina/genética , Proteína 2 Quinasa Serina-Treonina Rica en Repeticiones de Leucina/metabolismo , Proteínas Asociadas a Microtúbulos , Microtúbulos , Mutación , Enfermedad de Parkinson/metabolismo , Fosforilación , Proteínas Serina-Treonina Quinasas/genética , Factores de Transcripción , Proteínas de Motivos Tripartitos/metabolismo , Ubiquitina-Proteína Ligasas/genética , Ubiquitina-Proteína Ligasas/metabolismo , Ubiquitinación , Proteínas de Unión al GTP rab/metabolismo
7.
Cell Rep ; 38(6): 110351, 2022 02 08.
Artículo en Inglés | MEDLINE | ID: mdl-35139374

RESUMEN

KRAS, which is mutated in ∼30% of all cancers, activates the RAF-MEK-ERK signaling cascade. CRAF is required for growth of KRAS mutant lung tumors, but the requirement for CRAF kinase activity is unknown. Here, we show that subsets of KRAS mutant tumors are dependent on CRAF for growth. Kinase-dead but not dimer-defective CRAF rescues growth inhibition, suggesting that dimerization but not kinase activity is required. Quantitative proteomics demonstrates increased levels of CRAF:ARAF dimers in KRAS mutant cells, and depletion of both CRAF and ARAF rescues the CRAF-loss phenotype. Mechanistically, CRAF depletion causes sustained ERK activation and induction of cell-cycle arrest, while treatment with low-dose MEK or ERK inhibitor rescues the CRAF-loss phenotype. Our studies highlight the role of CRAF in regulating MAPK signal intensity to promote tumorigenesis downstream of mutant KRAS and suggest that disrupting CRAF dimerization or degrading CRAF may have therapeutic benefit.


Asunto(s)
Carcinogénesis/metabolismo , Dimerización , Proteínas Proto-Oncogénicas p21(ras)/metabolismo , Animales , Carcinogénesis/efectos de los fármacos , Línea Celular Tumoral , Humanos , Sistema de Señalización de MAP Quinasas/efectos de los fármacos , Ratones , Fosforilación/fisiología , Inhibidores de Proteínas Quinasas/farmacología , Proteínas Proto-Oncogénicas B-raf/genética , Transducción de Señal/efectos de los fármacos , Transducción de Señal/fisiología , Proteínas ras/genética
8.
J Biomol Struct Dyn ; 40(9): 4197-4207, 2022 06.
Artículo en Inglés | MEDLINE | ID: mdl-33297860

RESUMEN

Target evaluation is at the centre of rational drug design and biologics development. In order to successfully engineer antibodies, T-cell receptors or small molecules it is necessary to identify and characterise potential binding or contact sites on therapeutically relevant target proteins. Currently, there are numerous challenges in achieving a better docking precision as well as characterising relevant sites. We devised a first-of-its-kind in silico protein fingerprinting approach based on the dihedral angle and B-factor distribution to probe binding sites and sites of structural importance. Our derived Fi-score can be used to classify protein regions or individual structural subsets of interest and the described scoring system could be integrated into other discovery pipelines, such as protein classification databases, or applied to investigate new targets. We further demonstrated how our method can be integrated into machine learning Gaussian mixture models to predict different structural elements. Fi-score, in combination with other biophysical analytical methods depending on the research goals, could help to classify and systematically analyse not only targets but also drug candidates that bind to specific sites. The described methodology could greatly improve pre-screening stage, target selection and drug repurposing efforts in finding other matching targets. HIGHLIGHTSDescription and derivation of a first-of-its-kind in silico protein fingerprinting method using B-factors and dihedral angles.Derived Fi-score allows to characterise the whole protein or selected regions of interest.Demonstration how machine learning using Gaussian mixture models on Fi-scores captures and allows to predict functional protein topology elements.Fi-score is a novel method to help evaluate therapeutic targets and engineer effective biologics.Communicated by Ramaswamy H. Sarma.


Asunto(s)
Productos Biológicos , Descubrimiento de Drogas , Sitios de Unión , Descubrimiento de Drogas/métodos , Aprendizaje Automático , Proteínas/química
9.
PLoS One ; 16(12): e0260800, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-34879110

RESUMEN

The cancer-associated fibroblast (CAF) marker podoplanin (PDPN) is generally correlated with poor clinical outcomes in cancer patients and thus represents a promising therapeutic target. Despite its biomedical relevance, basic aspects of PDPN biology such as its cellular functions and cell surface ligands remain poorly uncharacterized, thus challenging drug development. Here, we utilize a high throughput platform to elucidate the PDPN cell surface interactome, and uncover the neutrophil protein CD177 as a new binding partner. Quantitative proteomics analysis of the CAF phosphoproteome reveals a role for PDPN in cell signaling, growth and actomyosin contractility, among other processes. Moreover, cellular assays demonstrate that CD177 is a functional antagonist, recapitulating the phenotype observed in PDPN-deficient CAFs. In sum, starting from the unbiased elucidation of the PDPN co-receptome, our work provides insights into PDPN functions and reveals the PDPN/CD177 axis as a possible modulator of fibroblast physiology in the tumor microenvironment.


Asunto(s)
Biomarcadores de Tumor/metabolismo , Fibroblastos Asociados al Cáncer/patología , Neoplasias Colorrectales/patología , Regulación Neoplásica de la Expresión Génica , Isoantígenos/metabolismo , Glicoproteínas de Membrana/metabolismo , Receptores de Superficie Celular/metabolismo , Microambiente Tumoral , Apoptosis , Biomarcadores de Tumor/genética , Fibroblastos Asociados al Cáncer/inmunología , Fibroblastos Asociados al Cáncer/metabolismo , Proliferación Celular , Neoplasias Colorrectales/genética , Neoplasias Colorrectales/inmunología , Neoplasias Colorrectales/metabolismo , Proteínas Ligadas a GPI/genética , Proteínas Ligadas a GPI/metabolismo , Humanos , Isoantígenos/genética , Glicoproteínas de Membrana/genética , Neutrófilos/inmunología , Neutrófilos/metabolismo , Pronóstico , Receptores de Superficie Celular/genética , Tasa de Supervivencia , Células Tumorales Cultivadas
10.
BMC Pulm Med ; 21(1): 301, 2021 Sep 23.
Artículo en Inglés | MEDLINE | ID: mdl-34556083

RESUMEN

BACKGROUND: Chronic obstructive pulmonary disease (COPD) exacerbations are heterogenous and profoundly impact the disease trajectory. Bioactive lipid lysophosphatidic acid (LPA) has been implicated in airway inflammation but the significance of LPA in COPD exacerbation is not known. The aim of the study was to investigate the utility of serum LPA species (LPA16:0, 18:0, 18:1, 18:2, 20:4) as biomarkers of COPD exacerbation. PATIENTS AND METHODS: LPA species were measured in the baseline placebo sera of a COPD randomized controlled trial. Tertile levels of each LPA were used to assign patients into biomarker high, medium, and low subgroups. Exacerbation rate and risk were compared among the LPA subgroups. RESULTS: The levels of LPA species were intercorrelated (rho 0.29-0.91). Patients with low and medium levels of LPA (LPA16:0, 20:4) had significantly higher exacerbation rate compared to the respective LPA-high patients [estimated rate per patient per year (95% CI)]: LPA16:0-low = 1.2 (0.8-1.9) (p = 0.019), LPA16:0-medium = 1.3 (0.8-2.0) (p = 0.013), LPA16:0-high = 0.5 (0.2-0.9); LPA20:4-low = 1.4 (0.9-2.1) (p = 0.0033), LPA20:4-medium = 1.2 (0.8-1.8) (p = 0.0089), LPA20:4-high = 0.4 (0.2-0.8). These patients also had earlier time to first exacerbation (hazard ratio (95% CI): LPA16:0-low = 2.6 (1.1-6.0) (p = 0.028), LPA16:0-medium = 2.7 (1.2-6.3) (p = 0.020); LPA20.4-low = 2.8 (1.2-6.6) (p = 0.017), LPA20:4-medium = 2.7 (1.2-6.4) (p = 0.021). Accordingly, these patients had a significant increased exacerbation risk compared to the respective LPA-high subgroups [odd ratio (95% CI)]: LPA16:0-low = 3.1 (1.1-8.8) (p = 0.030), LPA16:0-medium = 3.0 (1.1-8.3) (p = 0.031); LPA20:4-low = 3.8 (1.3-10.9) (p = 0.012), LPA20:4-medium = 3.3 (1.2-9.5) (p = 0.025). For the other LPA species (LPA18:0, 18:1, 18:2), the results were mixed; patients with low and medium levels of LPA18:0 and 18:2 had increased exacerbation rate, but only LPA18:0-low patients had significant increase in exacerbation risk and earlier time to first exacerbation compared to the LPA18:0-high subgroup. CONCLUSIONS: The study provided evidence of association between systemic LPA levels and exacerbation in COPD. Patients with low and medium levels of specific LPA species (LPA16:0, 20:4) had increased exacerbation rate, risk, and earlier time to first exacerbation. These non-invasive biomarkers may aid in identifying high risk patients with dysregulated LPA pathway to inform risk management and drug development.


Asunto(s)
Lisofosfolípidos/sangre , Enfermedad Pulmonar Obstructiva Crónica/sangre , Enfermedad Pulmonar Obstructiva Crónica/fisiopatología , Anciano , Biomarcadores/sangre , Progresión de la Enfermedad , Femenino , Humanos , Modelos Logísticos , Masculino , Persona de Mediana Edad , Modelos de Riesgos Proporcionales , Ensayos Clínicos Controlados Aleatorios como Asunto , Índice de Severidad de la Enfermedad
11.
Immunity ; 54(7): 1511-1526.e8, 2021 07 13.
Artículo en Inglés | MEDLINE | ID: mdl-34260887

RESUMEN

Myeloid cells encounter stromal cells and their matrix determinants on a continual basis during their residence in any given organ. Here, we examined the impact of the collagen receptor LAIR1 on myeloid cell homeostasis and function. LAIR1 was highly expressed in the myeloid lineage and enriched in non-classical monocytes. Proteomic definition of the LAIR1 interactome identified stromal factor Colec12 as a high-affinity LAIR1 ligand. Proteomic profiling of LAIR1 signaling triggered by Collagen1 and Colec12 highlighted pathways associated with survival, proliferation, and differentiation. Lair1-/- mice had reduced frequencies of Ly6C- monocytes, which were associated with altered proliferation and apoptosis of non-classical monocytes from bone marrow and altered heterogeneity of interstitial macrophages in lung. Myeloid-specific LAIR1 deficiency promoted metastatic growth in a melanoma model and LAIR1 expression associated with improved clinical outcomes in human metastatic melanoma. Thus, monocytes and macrophages rely on LAIR1 sensing of stromal determinants for fitness and function, with relevance in homeostasis and disease.


Asunto(s)
Homeostasis/fisiología , Pulmón/metabolismo , Macrófagos Alveolares/metabolismo , Monocitos/metabolismo , Receptores Inmunológicos/metabolismo , Animales , Apoptosis/fisiología , Médula Ósea/metabolismo , Médula Ósea/patología , Células COS , Diferenciación Celular/fisiología , Línea Celular , Línea Celular Tumoral , Linaje de la Célula/fisiología , Proliferación Celular/fisiología , Chlorocebus aethiops , Femenino , Humanos , Pulmón/patología , Macrófagos Alveolares/patología , Masculino , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados , Monocitos/patología , Células Mieloides/metabolismo , Células Mieloides/patología , Metástasis de la Neoplasia/patología , Proteómica/métodos , Transducción de Señal/fisiología
12.
Elife ; 102021 06 04.
Artículo en Inglés | MEDLINE | ID: mdl-34085925

RESUMEN

Defective autophagy is strongly associated with chronic inflammation. Loss-of-function of the core autophagy gene Atg16l1 increases risk for Crohn's disease in part by enhancing innate immunity through myeloid cells such as macrophages. However, autophagy is also recognized as a mechanism for clearance of certain intracellular pathogens. These divergent observations prompted a re-evaluation of ATG16L1 in innate antimicrobial immunity. In this study, we found that loss of Atg16l1 in myeloid cells enhanced the killing of virulent Shigella flexneri (S.flexneri), a clinically relevant enteric bacterium that resides within the cytosol by escaping from membrane-bound compartments. Quantitative multiplexed proteomics of murine bone marrow-derived macrophages revealed that ATG16L1 deficiency significantly upregulated proteins involved in the glutathione-mediated antioxidant response to compensate for elevated oxidative stress, which simultaneously promoted S.flexneri killing. Consistent with this, myeloid-specific deletion of Atg16l1 in mice accelerated bacterial clearance in vitro and in vivo. Pharmacological induction of oxidative stress through suppression of cysteine import enhanced microbial clearance by macrophages. Conversely, antioxidant treatment of macrophages permitted S.flexneri proliferation. These findings demonstrate that control of oxidative stress by ATG16L1 and autophagy regulates antimicrobial immunity against intracellular pathogens.


Asunto(s)
Proteínas Relacionadas con la Autofagia/deficiencia , Autofagia , Disentería Bacilar/microbiología , Inmunidad Innata , Macrófagos/microbiología , Estrés Oxidativo , Proteoma , Proteómica , Shigella flexneri/patogenicidad , Animales , Proteínas Relacionadas con la Autofagia/genética , Células Cultivadas , Modelos Animales de Enfermedad , Disentería Bacilar/inmunología , Disentería Bacilar/metabolismo , Interacciones Huésped-Patógeno , Mediadores de Inflamación/metabolismo , Macrófagos/inmunología , Macrófagos/metabolismo , Ratones Endogámicos C57BL , Ratones Noqueados , Viabilidad Microbiana , Shigella flexneri/inmunología , Shigella flexneri/metabolismo , Virulencia
13.
Cell Death Dis ; 12(4): 379, 2021 04 07.
Artículo en Inglés | MEDLINE | ID: mdl-33828080

RESUMEN

RIP1 kinase-mediated inflammatory and cell death pathways have been implicated in the pathology of acute and chronic disorders of the nervous system. Here, we describe a novel animal model of RIP1 kinase deficiency, generated by knock-in of the kinase-inactivating RIP1(D138N) mutation in rats. Homozygous RIP1 kinase-dead (KD) rats had normal development, reproduction and did not show any gross phenotypes at baseline. However, cells derived from RIP1 KD rats displayed resistance to necroptotic cell death. In addition, RIP1 KD rats were resistant to TNF-induced systemic shock. We studied the utility of RIP1 KD rats for neurological disorders by testing the efficacy of the genetic inactivation in the transient middle cerebral artery occlusion/reperfusion model of brain injury. RIP1 KD rats were protected in this model in a battery of behavioral, imaging, and histopathological endpoints. In addition, RIP1 KD rats had reduced inflammation and accumulation of neuronal injury biomarkers. Unbiased proteomics in the plasma identified additional changes that were ameliorated by RIP1 genetic inactivation. Together these data highlight the utility of the RIP1 KD rats for target validation and biomarker studies for neurological disorders.


Asunto(s)
Lesiones Encefálicas/genética , Muerte Celular/genética , Isquemia/genética , Proteínas Serina-Treonina Quinasas/metabolismo , Animales , Modelos Animales de Enfermedad , Masculino , Ratas , Ratas Sprague-Dawley , Proteína Serina-Treonina Quinasas de Interacción con Receptores
14.
J Am Soc Mass Spectrom ; 32(8): 1987-1997, 2021 Aug 04.
Artículo en Inglés | MEDLINE | ID: mdl-33754705

RESUMEN

Lysophospholipids are bioactive signaling molecules derived from cell membrane glycerophospholipids or sphingolipids and are highly regulated under normal physiological conditions. Lysophosphatidic acids (LPAs) are a class of lysophospholipids that act on G-protein-coupled receptors to exert a variety of cellular functions. Dysregulation of phospholipase activity and consequently LPA synthesis in serum have been linked to inflammation, such as seen in chronic obstructive pulmonary disease (COPD). The accurate measurement of phospholipids is critical for evaluating their dysregulation in disease. In this study, we optimized experimental parameters for the sensitive measurement of LPAs. We validated the method based on matrix, linearity, accuracy, precision, and stability. An investigation into sample extraction processes emphasized that the common practice of including low concentration of hydrochloric acid in the extraction buffer causes an overestimation of lipid recovery. The liquid chromatography gradient was optimized to separate various lysophospholipid classes. After optimization, detection limits of LPA were sufficiently sensitive for subsequent analysis, ranging from 2 to 8 nM. The validated workflow was applied to a cohort of healthy donor and COPD patient sera. Eight LPA species were identified, and five unique species of LPA were quantified. Most LPA species increased significantly in COPD patients compared to healthy donors. The correlation between LPAs and other demographic parameters was further investigated in a sample set of over 200 baseline patient sera from a COPD clinical trial. For the first time, LPAs other than the two most abundant and readily detectable moieties are quantified in COPD patients using validated methods, opening the door to downstream biomarker evaluation in respiratory disease.


Asunto(s)
Cromatografía Liquida/métodos , Lisofosfolípidos/sangre , Espectrometría de Masas/métodos , Enfermedad Pulmonar Obstructiva Crónica/sangre , Factores de Edad , Anciano , Biomarcadores/sangre , Análisis Químico de la Sangre/métodos , Índice de Masa Corporal , Estudios de Casos y Controles , Estudios de Cohortes , Femenino , Humanos , Límite de Detección , Lisofosfolípidos/aislamiento & purificación , Masculino , Persona de Mediana Edad , Enfermedad Pulmonar Obstructiva Crónica/etiología , Reproducibilidad de los Resultados , Capacidad Vital , Flujo de Trabajo
15.
Nat Methods ; 17(10): 981-984, 2020 10.
Artículo en Inglés | MEDLINE | ID: mdl-32929271

RESUMEN

MassIVE.quant is a repository infrastructure and data resource for reproducible quantitative mass spectrometry-based proteomics, which is compatible with all mass spectrometry data acquisition types and computational analysis tools. A branch structure enables MassIVE.quant to systematically store raw experimental data, metadata of the experimental design, scripts of the quantitative analysis workflow, intermediate input and output files, as well as alternative reanalyses of the same dataset.


Asunto(s)
Bases de Datos de Proteínas , Espectrometría de Masas , Proteómica , Algoritmos , Proteínas Fúngicas/química , Reproducibilidad de los Resultados , Saccharomyces cerevisiae/metabolismo , Programas Informáticos
16.
Nature ; 584(7821): 479-483, 2020 08.
Artículo en Inglés | MEDLINE | ID: mdl-32788728

RESUMEN

Lipopolysaccharide (LPS) resides in the outer membrane of Gram-negative bacteria where it is responsible for barrier function1,2. LPS can cause death as a result of septic shock, and its lipid A core is the target of polymyxin antibiotics3,4. Despite the clinical importance of polymyxins and the emergence of multidrug resistant strains5, our understanding of the bacterial factors that regulate LPS biogenesis is incomplete. Here we characterize the inner membrane protein PbgA and report that its depletion attenuates the virulence of Escherichia coli by reducing levels of LPS and outer membrane integrity. In contrast to previous claims that PbgA functions as a cardiolipin transporter6-9, our structural analyses and physiological studies identify a lipid A-binding motif along the periplasmic leaflet of the inner membrane. Synthetic PbgA-derived peptides selectively bind to LPS in vitro and inhibit the growth of diverse Gram-negative bacteria, including polymyxin-resistant strains. Proteomic, genetic and pharmacological experiments uncover a model in which direct periplasmic sensing of LPS by PbgA coordinates the biosynthesis of lipid A by regulating the stability of LpxC, a key cytoplasmic biosynthetic enzyme10-12. In summary, we find that PbgA has an unexpected but essential role in the regulation of LPS biogenesis, presents a new structural basis for the selective recognition of lipids, and provides opportunities for future antibiotic discovery.


Asunto(s)
Membrana Celular/química , Proteínas de Escherichia coli/química , Proteínas de Escherichia coli/metabolismo , Escherichia coli/química , Escherichia coli/patogenicidad , Lipopolisacáridos/química , Lipopolisacáridos/metabolismo , Amidohidrolasas/química , Amidohidrolasas/metabolismo , Secuencias de Aminoácidos , Membrana Externa Bacteriana/química , Membrana Externa Bacteriana/metabolismo , Sitios de Unión , Membrana Celular/metabolismo , Estabilidad de Enzimas , Escherichia coli/citología , Escherichia coli/efectos de los fármacos , Genes Esenciales , Hidrolasas/química , Hidrolasas/metabolismo , Lípido A/química , Lípido A/metabolismo , Lipopolisacáridos/biosíntesis , Pruebas de Sensibilidad Microbiana , Viabilidad Microbiana/efectos de los fármacos , Modelos Moleculares , Fragmentos de Péptidos/química , Fragmentos de Péptidos/metabolismo , Fragmentos de Péptidos/farmacología , Periplasma/química , Periplasma/metabolismo , Unión Proteica , Virulencia
17.
Cell ; 182(2): 329-344.e19, 2020 07 23.
Artículo en Inglés | MEDLINE | ID: mdl-32589946

RESUMEN

Cell surface receptors and their interactions play a central role in physiological and pathological signaling. Despite its clinical relevance, the immunoglobulin superfamily (IgSF) remains uncharacterized and underrepresented in databases. Here, we present a systematic extracellular protein map, the IgSF interactome. Using a high-throughput technology to interrogate most single transmembrane receptors for binding to 445 IgSF proteins, we identify over 500 interactions, 82% previously undocumented, and confirm more than 60 receptor-ligand pairs using orthogonal assays. Our study reveals a map of cell-type-specific interactions and the landscape of dysregulated receptor-ligand crosstalk in cancer, including selective loss of function for tumor-associated mutations. Furthermore, investigation of the IgSF interactome in a large cohort of cancer patients identifies interacting protein signatures associated with clinical outcome. The IgSF interactome represents an important resource to fuel biological discoveries and a framework for understanding the functional organization of the surfaceome during homeostasis and disease, ultimately informing therapeutic development.


Asunto(s)
Inmunoglobulinas/metabolismo , Neoplasias/patología , Mapas de Interacción de Proteínas , Antígeno B7-H1/metabolismo , Antígeno Carcinoembrionario/metabolismo , Comunicación Celular , Análisis por Conglomerados , Medios de Cultivo Condicionados/química , Células HEK293 , Humanos , Inmunoglobulinas/química , Inmunoglobulinas/genética , Ligandos , Mutación , Neoplasias/genética , Neoplasias/metabolismo , Unión Proteica , Receptores de Superficie Celular/química , Receptores de Superficie Celular/genética , Receptores de Superficie Celular/metabolismo , Linfocitos T/citología , Linfocitos T/inmunología , Linfocitos T/metabolismo
18.
Mol Cell ; 77(5): 1107-1123.e10, 2020 03 05.
Artículo en Inglés | MEDLINE | ID: mdl-32142684

RESUMEN

Mitochondria import nearly their entire proteome from the cytoplasm by translocating precursor proteins through the translocase of the outer membrane (TOM) complex. Here, we show dynamic regulation of mitochondrial import by the ubiquitin system. Acute pharmacological inhibition or genetic ablation of the mitochondrial deubiquitinase (DUB) USP30 triggers accumulation of Ub-substrates that are normally localized inside the mitochondria. Mitochondrial import of USP30 substrates is impaired in USP30 knockout (KO) cells, suggesting that deubiquitination promotes efficient import. Upstream of USP30, the E3 ligase March5 ubiquitinates mitochondrial proteins whose eventual import depends on USP30. In USP30 KOs, exogenous March5 expression induces accumulation of unimported translocation intermediates that are degraded by the proteasomes. In USP30 KO mice, TOM subunits have reduced abundance across multiple tissues. Together these data highlight how protein import into a subcellular compartment can be regulated by ubiquitination and deubiquitination by E3 ligase and DUB machinery positioned at the gate.


Asunto(s)
Proteínas Portadoras/metabolismo , Proteínas de la Membrana/metabolismo , Mitocondrias/enzimología , Proteínas Mitocondriales/metabolismo , Tioléster Hidrolasas/metabolismo , Ubiquitina-Proteína Ligasas/metabolismo , Ubiquitina/metabolismo , Animales , Transporte Biológico , Proteínas Portadoras/genética , Femenino , Células HEK293 , Células HeLa , Humanos , Masculino , Proteínas de la Membrana/genética , Ratones Endogámicos C57BL , Ratones Noqueados , Mitocondrias/genética , Proteínas del Complejo de Importación de Proteínas Precursoras Mitocondriales , Proteínas Mitocondriales/genética , Complejo de la Endopetidasa Proteasomal/genética , Complejo de la Endopetidasa Proteasomal/metabolismo , Proteolisis , Tioléster Hidrolasas/genética , Factores de Tiempo , Ubiquitina-Proteína Ligasas/genética , Ubiquitinación
19.
Nat Struct Mol Biol ; 27(2): 210-220, 2020 02.
Artículo en Inglés | MEDLINE | ID: mdl-32015554

RESUMEN

Neddylation is the post-translational protein modification most closely related to ubiquitination. Whereas the ubiquitin-like protein NEDD8 is well studied for its role in activating cullin-RING E3 ubiquitin ligases, little is known about other substrates. We developed serial NEDD8-ubiquitin substrate profiling (sNUSP), a method that employs NEDD8 R74K knock-in HEK293 cells, allowing discrimination of endogenous NEDD8- and ubiquitin-modification sites by MS after Lys-C digestion and K-εGG-peptide enrichment. Using sNUSP, we identified 607 neddylation sites dynamically regulated by the neddylation inhibitor MLN4924 and the de-neddylating enzyme NEDP1, implying that many non-cullin proteins are neddylated. Among the candidates, we characterized lysine 112 of the actin regulator cofilin as a novel neddylation event. Global inhibition of neddylation in developing neurons leads to cytoskeletal defects, altered actin dynamics and neurite growth impairments, whereas site-specific neddylation of cofilin at K112 regulates neurite outgrowth, suggesting that cofilin neddylation contributes to the regulation of neuronal actin organization.


Asunto(s)
Actinas/metabolismo , Cofilina 1/metabolismo , Proteína NEDD8/metabolismo , Neuronas/metabolismo , Animales , Línea Celular , Células Cultivadas , Técnicas de Sustitución del Gen , Células HEK293 , Humanos , Ratones , Ratones Endogámicos C57BL , Proteína NEDD8/genética , Neuronas/citología , Mutación Puntual , Ratas , Ratas Sprague-Dawley , Ubiquitina/metabolismo , Ubiquitinación
20.
Mol Cell ; 78(2): 197-209.e7, 2020 04 16.
Artículo en Inglés | MEDLINE | ID: mdl-32084337

RESUMEN

We have developed a platform for quantitative genetic interaction mapping using viral infectivity as a functional readout and constructed a viral host-dependency epistasis map (vE-MAP) of 356 human genes linked to HIV function, comprising >63,000 pairwise genetic perturbations. The vE-MAP provides an expansive view of the genetic dependencies underlying HIV infection and can be used to identify drug targets and study viral mutations. We found that the RNA deadenylase complex, CNOT, is a central player in the vE-MAP and show that knockout of CNOT1, 10, and 11 suppressed HIV infection in primary T cells by upregulating innate immunity pathways. This phenotype was rescued by deletion of IRF7, a transcription factor regulating interferon-stimulated genes, revealing a previously unrecognized host signaling pathway involved in HIV infection. The vE-MAP represents a generic platform that can be used to study the global effects of how different pathogens hijack and rewire the host during infection.


Asunto(s)
Epistasis Genética , Infecciones por VIH/genética , Factor 7 Regulador del Interferón/genética , Factores de Transcripción/genética , Linfocitos T CD4-Positivos/inmunología , Linfocitos T CD4-Positivos/patología , Infecciones por VIH/inmunología , Infecciones por VIH/patología , Infecciones por VIH/virología , VIH-1/genética , VIH-1/patogenicidad , Interacciones Huésped-Patógeno/genética , Interacciones Huésped-Patógeno/inmunología , Humanos , Inmunidad Innata/genética , Interferones/genética , Mutación , Transducción de Señal/genética
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