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1.
BMC Microbiol ; 24(1): 152, 2024 May 03.
Artículo en Inglés | MEDLINE | ID: mdl-38702660

RESUMEN

BACKGROUND: Pseudomonas aeruginosa is a common cause of nosocomial infections. However, the emergence of multidrug-resistant strains has complicated the treatment of P. aeruginosa infections. While polymyxins have been the mainstay for treatment, there is a global increase in resistance to these antibiotics. Therefore, our study aimed to determine the prevalence and molecular details of colistin resistance in P. aeruginosa clinical isolates collected between June 2019 and May 2023, as well as the genetic linkage of colistin-resistant P. aeruginosa isolates. RESULTS: The resistance rate to colistin was 9% (n = 18) among P. aeruginosa isolates. All 18 colistin-resistant isolates were biofilm producers and carried genes associated with biofilm formation. Furthermore, the presence of genes encoding efflux pumps, TCSs, and outer membrane porin was observed in all colistin-resistant P. aeruginosa strains, while the mcr-1 gene was not detected. Amino acid substitutions were identified only in the PmrB protein of multidrug- and colistin-resistant strains. The expression levels of mexA, mexC, mexE, mexY, phoP, and pmrA genes in the 18 colistin-resistant P. aeruginosa strains were as follows: 88.8%, 94.4%, 11.1%, 83.3%, 83.3%, and 38.8%, respectively. Additionally, down-regulation of the oprD gene was observed in 44.4% of colistin-resistant P. aeruginosa strains. CONCLUSION: This study reports the emergence of colistin resistance with various mechanisms among P. aeruginosa strains in Ardabil hospitals. We recommend avoiding unnecessary use of colistin to prevent potential future increases in colistin resistance.


Asunto(s)
Antibacterianos , Proteínas Bacterianas , Colistina , Pruebas de Sensibilidad Microbiana , Infecciones por Pseudomonas , Pseudomonas aeruginosa , Factores de Transcripción , Colistina/farmacología , Pseudomonas aeruginosa/genética , Pseudomonas aeruginosa/efectos de los fármacos , Pseudomonas aeruginosa/aislamiento & purificación , Antibacterianos/farmacología , Humanos , Proteínas Bacterianas/genética , Infecciones por Pseudomonas/microbiología , Infecciones por Pseudomonas/epidemiología , Prevalencia , Farmacorresistencia Bacteriana Múltiple/genética , Biopelículas/efectos de los fármacos , Biopelículas/crecimiento & desarrollo , Hospitales , Farmacorresistencia Bacteriana/genética , Infección Hospitalaria/microbiología , Infección Hospitalaria/epidemiología , Proteínas de Transporte de Membrana/genética , Porinas/genética
2.
Proc Natl Acad Sci U S A ; 121(22): e2321600121, 2024 May 28.
Artículo en Inglés | MEDLINE | ID: mdl-38771881

RESUMEN

Antigen presentation via major histocompatibility complex class I (MHC-I) molecules is essential for surveillance by the adaptive immune system. Central to this process is the peptide-loading complex (PLC), which translocates peptides from the cytosol to the endoplasmic reticulum and catalyzes peptide loading and proofreading of peptide-MHC-I (pMHC-I) complexes. Despite its importance, the impact of individual PLC components on the presented pMHC-I complexes is still insufficiently understood. Here, we used stoichiometrically defined antibody-nanobody complexes and engineered soluble T cell receptors (sTCRs) to quantify different MHC-I allomorphs and defined pMHC-I complexes, respectively. Thereby, we uncovered distinct effects of individual PLC components on the pMHC-I surface pool. Knockouts of components of the PLC editing modules, namely tapasin, ERp57, or calreticulin, changed the MHC-I surface composition to a reduced proportion of HLA-A*02:01 presentation compensated by a higher ratio of HLA-B*40:01 molecules. Intriguingly, these knockouts not only increased the presentation of suboptimally loaded HLA-A*02:01 complexes but also elevated the presentation of high-affinity peptides overexpressed in the cytosol. Our findings suggest that the components of the PLC editing module serve a dual role, acting not only as peptide proofreaders but also as limiters for abundant peptides. This dual function ensures the presentation of a broad spectrum of antigenic peptides.


Asunto(s)
Presentación de Antígeno , Antígenos de Histocompatibilidad Clase I , Péptidos , Presentación de Antígeno/inmunología , Humanos , Péptidos/metabolismo , Péptidos/inmunología , Antígenos de Histocompatibilidad Clase I/metabolismo , Antígenos de Histocompatibilidad Clase I/genética , Antígenos de Histocompatibilidad Clase I/inmunología , Calreticulina/metabolismo , Calreticulina/genética , Proteína Disulfuro Isomerasas/metabolismo , Proteína Disulfuro Isomerasas/genética , Receptores de Antígenos de Linfocitos T/metabolismo , Receptores de Antígenos de Linfocitos T/inmunología , Proteínas de Transporte de Membrana/metabolismo , Proteínas de Transporte de Membrana/genética , Retículo Endoplásmico/metabolismo
3.
Commun Biol ; 7(1): 610, 2024 May 21.
Artículo en Inglés | MEDLINE | ID: mdl-38773269

RESUMEN

The processes of nutrient uptake and signal sensing are crucial for microbial survival and adaptation. Membrane-embedded proteins involved in these functions (transporters and receptors) are commonly regarded as unrelated in terms of sequence, structure, mechanism of action and evolutionary history. Here, we analyze the protein structural universe using recently developed artificial intelligence-based structure prediction tools, and find an unexpected link between prominent groups of microbial transporters and receptors. The so-called S-components of Energy-Coupling Factor (ECF) transporters, and the membrane domains of sensor histidine kinases of the 5TMR cluster share a structural fold. The discovery of their relatedness manifests a widespread case of prokaryotic "transceptors" (related proteins with transport or receptor function), showcases how artificial intelligence-based structure predictions reveal unchartered evolutionary connections between proteins, and provides new avenues for engineering transport and signaling functions in bacteria.


Asunto(s)
Proteínas Bacterianas , Proteínas de Transporte de Membrana , Proteínas Bacterianas/metabolismo , Proteínas Bacterianas/química , Proteínas Bacterianas/genética , Proteínas de Transporte de Membrana/metabolismo , Proteínas de Transporte de Membrana/química , Proteínas de Transporte de Membrana/genética , Histidina Quinasa/metabolismo , Histidina Quinasa/química , Histidina Quinasa/genética , Modelos Moleculares , Bacterias/metabolismo , Bacterias/genética , Transducción de Señal , Pliegue de Proteína , Inteligencia Artificial
4.
Immunohematology ; 40(1): 28-33, 2024 Apr 01.
Artículo en Inglés | MEDLINE | ID: mdl-38739024

RESUMEN

Since publication of the original Immunohematology review of the Kidd blood group system in 2015 (Hamilton JR. Kidd blood group system: a review. Immunohematology 2015;31:29-34), knowledge has mushroomed pertaining to gene structure, alleles causing variant and null phenotypes, clinical significance in renal transplant and hemolytic disease of the fetus and newborn, and physiologic functions of urea transporters in non-renal tissues. This review will detail much of this new information.


Asunto(s)
Sistema del Grupo Sanguíneo de Kidd , Trasplante de Riñón , Humanos , Sistema del Grupo Sanguíneo de Kidd/genética , Sistema del Grupo Sanguíneo de Kidd/inmunología , Transportadores de Urea , Eritroblastosis Fetal/genética , Eritroblastosis Fetal/inmunología , Eritroblastosis Fetal/sangre , Recién Nacido , Proteínas de Transporte de Membrana/genética , Alelos , Antígenos de Grupos Sanguíneos/genética , Antígenos de Grupos Sanguíneos/inmunología
5.
Sci Adv ; 10(20): eadn5143, 2024 May 17.
Artículo en Inglés | MEDLINE | ID: mdl-38748788

RESUMEN

Marine heterotrophic prokaryotes primarily take up ambient substrates using transporters. The patterns of transporters targeting particular substrates shape the ecological role of heterotrophic prokaryotes in marine organic matter cycles. Here, we report a size-fractionated pattern in the expression of prokaryotic transporters throughout the oceanic water column due to taxonomic variations, revealed by a multi-"omics" approach targeting ATP-binding cassette (ABC) transporters and TonB-dependent transporters (TBDTs). Substrate specificity analyses showed that marine SAR11, Rhodobacterales, and Oceanospirillales use ABC transporters to take up organic nitrogenous compounds in the free-living fraction, while Alteromonadales, Bacteroidetes, and Sphingomonadales use TBDTs for carbon-rich organic matter and metal chelates on particles. The expression of transporter proteins also supports distinct lifestyles of deep-sea prokaryotes. Our results suggest that transporter divergency in organic matter assimilation reflects a pronounced niche separation in the prokaryote-mediated organic matter cycles.


Asunto(s)
Microbiota , Agua de Mar/microbiología , Células Procariotas/metabolismo , Transportadoras de Casetes de Unión a ATP/metabolismo , Especificidad por Sustrato , Filogenia , Bacterias/metabolismo , Bacterias/clasificación , Organismos Acuáticos/metabolismo , Proteínas de Transporte de Membrana/metabolismo , Carbono/metabolismo
6.
Sci Rep ; 14(1): 10596, 2024 05 08.
Artículo en Inglés | MEDLINE | ID: mdl-38720048

RESUMEN

To investigate the association between hereditary hearing loss and vestibular function, we compared vestibular function and symptoms among patients with GJB2, SLC26A4, and CDH23 variants. Thirty-nine patients with sensory neural hearing loss (11 males and 28 females) with biallelic pathogenic variants in either GJB2, SLC26A4, or CDH23 were included in this study (13 GJB2, 15 SLC26A4, and 11 CDH23). The patients were examined using caloric testing and cervical and ocular vestibular-evoked myogenic potentials (cVEMP and oVEMP). We also compared vestibular function and symptoms between patients with these gene variants and 78 normal-hearing ears without vestibular symptoms as controls. The frequency of semicircular canal hypofunction in caloric testing was higher in patients with SLC26A4 variants (47%) than in those with GJB2 (0%) and CDH23 variants (27%). According to the cVEMP results, 69% of patients with GJB2 variants had saccular hypofunction, a significantly higher proportion than in those carrying other variants (SLC26A4, 20%; CDH23, 18%). In oVEMP, which reflects utricular function, no difference was observed in the frequency of hypofunction among the three genes (GJB2, 15%; SLC26A4, 40%; and CDH23, 36%). Hence, discernable trends indicate vestibular dysfunction associated with each gene.


Asunto(s)
Proteínas Relacionadas con las Cadherinas , Cadherinas , Conexina 26 , Transportadores de Sulfato , Humanos , Femenino , Masculino , Cadherinas/genética , Transportadores de Sulfato/genética , Conexina 26/genética , Adulto , Adolescente , Persona de Mediana Edad , Niño , Adulto Joven , Potenciales Vestibulares Miogénicos Evocados , Proteínas de Transporte de Membrana/genética , Pérdida Auditiva Sensorineural/genética , Pérdida Auditiva Sensorineural/fisiopatología , Pruebas de Función Vestibular , Preescolar , Vestíbulo del Laberinto/fisiopatología , Conexinas/genética
7.
Int J Mol Sci ; 25(9)2024 Apr 25.
Artículo en Inglés | MEDLINE | ID: mdl-38731891

RESUMEN

The past five decades have witnessed remarkable advancements in the field of inhaled medicines targeting the lungs for respiratory disease treatment. As a non-invasive drug delivery route, inhalation therapy offers numerous benefits to respiratory patients, including rapid and targeted exposure at specific sites, quick onset of action, bypassing first-pass metabolism, and beyond. Understanding the characteristics of pulmonary drug transporters and metabolizing enzymes is crucial for comprehending efficient drug exposure and clearance processes within the lungs. These processes are intricately linked to both local and systemic pharmacokinetics and pharmacodynamics of drugs. This review aims to provide a comprehensive overview of the literature on lung transporters and metabolizing enzymes while exploring their roles in exogenous and endogenous substance disposition. Additionally, we identify and discuss the principal challenges in this area of research, providing a foundation for future investigations aimed at optimizing inhaled drug administration. Moving forward, it is imperative that future research endeavors to focus on refining and validating in vitro and ex vivo models to more accurately mimic the human respiratory system. Such advancements will enhance our understanding of drug processing in different pathological states and facilitate the discovery of novel approaches for investigating lung-specific drug transporters and metabolizing enzymes. This deeper insight will be crucial in developing more effective and targeted therapies for respiratory diseases, ultimately leading to improved patient outcomes.


Asunto(s)
Pulmón , Proteínas de Transporte de Membrana , Humanos , Administración por Inhalación , Pulmón/metabolismo , Proteínas de Transporte de Membrana/metabolismo , Animales , Preparaciones Farmacéuticas/metabolismo , Preparaciones Farmacéuticas/administración & dosificación , Transporte Biológico
8.
BMC Cancer ; 24(1): 602, 2024 May 17.
Artículo en Inglés | MEDLINE | ID: mdl-38760735

RESUMEN

BACKGROUND: Melanoma proliferation is partly attributed to dysregulated lipid metabolism. The effectiveness of lipid-lowering drugs in combating cutaneous melanoma (CM) is a subject of ongoing debate in both in vitro and clinical studies. METHOD: This study aims to evaluate the causal relationship between various lipid-lowering drug targets, namely 3-hydroxy-3-methylglutaryl-coenzyme A reductase (HMGCR, targeted by statins), Proprotein convertase subtilisin/kexin type 9 (PCSK9, targeted by alirocumab and evolocumab), and Niemann-Pick C1-like 1 (NPC1L1, targeted by ezetimibe), and the outcomes of cutaneous melanoma. To mimic the effects of lipid-lowering drugs, we utilized two genetic tools: analysis of polymorphisms affecting the expression levels of drug target genes, and genetic variations linked to low-density lipoprotein cholesterol levels and drug target genes. These variations were sourced from genome-wide association studies (GWAS). We applied Summary-data-based Mendelian Randomization (SMR) and Inverse Variance Weighted Mendelian Randomization (IVW-MR) to gauge the effectiveness of these drugs. RESULTS: Our findings, with SMR results showing an odds ratio (OR) of 1.44 (95% CI: 1.08-1.92; P = 0.011) and IVW-MR results indicating an OR of 1.56 (95% CI: 1.10-2.23; P = 0.013), demonstrate a positive correlation between PCSK9 expression and increased risk of CM. However, no such correlations were observed in other analyses. CONCLUSION: The study concludes that PCSK9 plays a significant role in the development of CM, and its inhibition is linked to a reduced risk of the disease.


Asunto(s)
Estudio de Asociación del Genoma Completo , Hidroximetilglutaril-CoA Reductasas , Melanoma , Análisis de la Aleatorización Mendeliana , Proproteína Convertasa 9 , Neoplasias Cutáneas , Humanos , Melanoma/genética , Melanoma/tratamiento farmacológico , Neoplasias Cutáneas/genética , Neoplasias Cutáneas/tratamiento farmacológico , Proproteína Convertasa 9/genética , Hidroximetilglutaril-CoA Reductasas/genética , Melanoma Cutáneo Maligno , Anticuerpos Monoclonales Humanizados/uso terapéutico , Polimorfismo de Nucleótido Simple , Proteínas de Transporte de Membrana/genética , Proteínas de la Membrana/genética , Inhibidores de Hidroximetilglutaril-CoA Reductasas/uso terapéutico , Ezetimiba/uso terapéutico , Hipolipemiantes/uso terapéutico , Hipolipemiantes/farmacología
9.
J Exp Med ; 221(8)2024 Aug 05.
Artículo en Inglés | MEDLINE | ID: mdl-38780621

RESUMEN

Nucleic acid-sensing Toll-like receptors (TLR) 3, 7/8, and 9 are key innate immune sensors whose activities must be tightly regulated to prevent systemic autoimmune or autoinflammatory disease or virus-associated immunopathology. Here, we report a systematic scanning-alanine mutagenesis screen of all cytosolic and luminal residues of the TLR chaperone protein UNC93B1, which identified both negative and positive regulatory regions affecting TLR3, TLR7, and TLR9 responses. We subsequently identified two families harboring heterozygous coding mutations in UNC93B1, UNC93B1+/T93I and UNC93B1+/R336C, both in key negative regulatory regions identified in our screen. These patients presented with cutaneous tumid lupus and juvenile idiopathic arthritis plus neuroinflammatory disease, respectively. Disruption of UNC93B1-mediated regulation by these mutations led to enhanced TLR7/8 responses, and both variants resulted in systemic autoimmune or inflammatory disease when introduced into mice via genome editing. Altogether, our results implicate the UNC93B1-TLR7/8 axis in human monogenic autoimmune diseases and provide a functional resource to assess the impact of yet-to-be-reported UNC93B1 mutations.


Asunto(s)
Autoinmunidad , Animales , Humanos , Ratones , Autoinmunidad/genética , Proteínas de Transporte de Membrana/genética , Proteínas de Transporte de Membrana/metabolismo , Análisis Mutacional de ADN , Receptores Toll-Like/metabolismo , Receptores Toll-Like/genética , Mutación , Femenino , Masculino , Ratones Endogámicos C57BL , Células HEK293 , Receptor Toll-Like 7/genética , Receptor Toll-Like 7/metabolismo , Enfermedades Autoinmunes/genética , Enfermedades Autoinmunes/inmunología
10.
Microb Cell Fact ; 23(1): 152, 2024 May 24.
Artículo en Inglés | MEDLINE | ID: mdl-38790017

RESUMEN

BACKGROUND: A novel plasmid-mediated resistance-nodulation-division (RND) efflux pump gene cluster tmexCD1-toprJ1 in Klebsiella pneumoniae tremendously threatens the use of convenient therapeutic options in the post-antibiotic era, including the "last-resort" antibiotic tigecycline. RESULTS: In this work, the natural alkaloid harmaline was found to potentiate tigecycline efficacy (4- to 32-fold) against tmexCD1-toprJ1-positive K. pneumoniae, which also thwarted the evolution of tigecycline resistance. Galleria mellonella and mouse infection models in vivo further revealed that harmaline is a promising candidate to reverse tigecycline resistance. Inspiringly, harmaline works synergistically with tigecycline by undermining tmexCD1-toprJ1-mediated multidrug resistance efflux pump function via interactions with TMexCD1-TOprJ1 active residues and dissipation of the proton motive force (PMF), and triggers a vicious cycle of disrupting cell membrane integrity and metabolic homeostasis imbalance. CONCLUSION: These results reveal the potential of harmaline as a novel tigecycline adjuvant to combat hypervirulent K. pneumoniae infections.


Asunto(s)
Antibacterianos , Reposicionamiento de Medicamentos , Harmalina , Infecciones por Klebsiella , Klebsiella pneumoniae , Tigeciclina , Klebsiella pneumoniae/efectos de los fármacos , Tigeciclina/farmacología , Infecciones por Klebsiella/tratamiento farmacológico , Infecciones por Klebsiella/microbiología , Animales , Ratones , Antibacterianos/farmacología , Harmalina/farmacología , Harmalina/análogos & derivados , Pruebas de Sensibilidad Microbiana , Farmacorresistencia Bacteriana Múltiple , Proteínas Bacterianas/metabolismo , Proteínas Bacterianas/genética , Proteínas de Transporte de Membrana/metabolismo , Proteínas de Transporte de Membrana/genética , Femenino
11.
Microb Biotechnol ; 17(5): e14487, 2024 May.
Artículo en Inglés | MEDLINE | ID: mdl-38801351

RESUMEN

Pseudomonas aeruginosa is a notorious multidrug-resistant pathogen that poses a serious and growing threat to the worldwide public health. The expression of resistance determinants is exquisitely modulated by the abundant regulatory proteins and the intricate signal sensing and transduction systems in this pathogen. Downregulation of antibiotic influx porin proteins and upregulation of antibiotic efflux pump systems owing to mutational changes in their regulators or the presence of distinct inducing molecular signals represent two of the most efficient mechanisms that restrict intracellular antibiotic accumulation and enable P. aeruginosa to resist multiple antibiotics. Treatment of P. aeruginosa infections is extremely challenging due to the highly inducible mechanism of antibiotic resistance. This review comprehensively summarizes the regulatory networks of the major porin proteins (OprD and OprH) and efflux pumps (MexAB-OprM, MexCD-OprJ, MexEF-OprN, and MexXY) that play critical roles in antibiotic influx and efflux in P. aeruginosa. It also discusses promising therapeutic approaches using safe and efficient adjuvants to enhance the efficacy of conventional antibiotics to combat multidrug-resistant P. aeruginosa by controlling the expression levels of porins and efflux pumps. This review not only highlights the complexity of the regulatory network that induces antibiotic resistance in P. aeruginosa but also provides important therapeutic implications in targeting the inducible mechanism of resistance.


Asunto(s)
Antibacterianos , Regulación Bacteriana de la Expresión Génica , Proteínas de Transporte de Membrana , Pseudomonas aeruginosa , Pseudomonas aeruginosa/genética , Pseudomonas aeruginosa/efectos de los fármacos , Pseudomonas aeruginosa/metabolismo , Antibacterianos/farmacología , Antibacterianos/metabolismo , Humanos , Proteínas de Transporte de Membrana/metabolismo , Proteínas de Transporte de Membrana/genética , Infecciones por Pseudomonas/tratamiento farmacológico , Infecciones por Pseudomonas/microbiología , Farmacorresistencia Bacteriana Múltiple/genética , Porinas/metabolismo , Porinas/genética , Proteínas Bacterianas/genética , Proteínas Bacterianas/metabolismo , Transporte Biológico
12.
Int J Biol Macromol ; 269(Pt 2): 132166, 2024 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-38723822

RESUMEN

Improving the ability of bacteria to secrete protein is essential for large-scale production of food enzymes. However, due to the lack of effective tracking technology for target proteins, the optimization of the secretory system is facing many problems. In this study, we utilized the split-GFP system to achieve self-assembly into mature GFP in Bacillus amyloliquefaciens and successfully tracked the alkaline protease AprE. The split-GFP system was employed to assess the signal peptidases, a crucial component in the secretory system, and signal peptidase sipA was identified as playing a role in the secretion of AprE. Deletion of sipA resulted in a higher accumulation of the precursor protein of AprE compared to other signal peptidase deletion strains. To explore the mechanism of signal peptidase on signal peptide, molecular docking and calculation of free energy were performed. The action strength of the signal peptidase is determined by its binding affinity with the tripeptides at the C-terminal of the signal peptide. The functions of signal peptides YdbK and NucB rely on sipA, and overexpression of sipA by integrating it into genome of B. amyloliquefaciens increased the activity of extracellular AprE by 19.9 %. These findings provide insights into enhancing the secretion efficiency of chassis strains.


Asunto(s)
Bacillus amyloliquefaciens , Proteínas Bacterianas , Endopeptidasas , Proteínas Fluorescentes Verdes , Bacillus amyloliquefaciens/enzimología , Bacillus amyloliquefaciens/genética , Bacillus amyloliquefaciens/metabolismo , Proteínas Bacterianas/genética , Proteínas Bacterianas/metabolismo , Proteínas Bacterianas/química , Endopeptidasas/metabolismo , Endopeptidasas/genética , Endopeptidasas/química , Proteínas Fluorescentes Verdes/metabolismo , Proteínas Fluorescentes Verdes/genética , Simulación del Acoplamiento Molecular , Señales de Clasificación de Proteína , Proteínas de la Membrana , Serina Endopeptidasas , Proteínas de Transporte de Membrana
13.
Nature ; 629(8012): 704-709, 2024 May.
Artículo en Inglés | MEDLINE | ID: mdl-38693257

RESUMEN

Choline is an essential nutrient that the human body needs in vast quantities for cell membrane synthesis, epigenetic modification and neurotransmission. The brain has a particularly high demand for choline, but how it enters the brain remains unknown1-3. The major facilitator superfamily transporter FLVCR1 (also known as MFSD7B or SLC49A1) was recently determined to be a choline transporter but is not highly expressed at the blood-brain barrier, whereas the related protein FLVCR2 (also known as MFSD7C or SLC49A2) is expressed in endothelial cells at the blood-brain barrier4-7. Previous studies have shown that mutations in human Flvcr2 cause cerebral vascular abnormalities, hydrocephalus and embryonic lethality, but the physiological role of FLVCR2 is unknown4,5. Here we demonstrate both in vivo and in vitro that FLVCR2 is a BBB choline transporter and is responsible for the majority of choline uptake into the brain. We also determine the structures of choline-bound FLVCR2 in both inward-facing and outward-facing states using cryo-electron microscopy. These results reveal how the brain obtains choline and provide molecular-level insights into how FLVCR2 binds choline in an aromatic cage and mediates its uptake. Our work could provide a novel framework for the targeted delivery of therapeutic agents into the brain.


Asunto(s)
Barrera Hematoencefálica , Encéfalo , Colina , Microscopía por Crioelectrón , Proteínas de Transporte de Membrana , Modelos Moleculares , Colina/metabolismo , Animales , Humanos , Encéfalo/metabolismo , Ratones , Barrera Hematoencefálica/metabolismo , Proteínas de Transporte de Membrana/metabolismo , Proteínas de Transporte de Membrana/química , Proteínas de Transporte de Membrana/genética , Femenino , Masculino , Transporte Biológico
14.
Nature ; 629(8012): 710-716, 2024 May.
Artículo en Inglés | MEDLINE | ID: mdl-38693265

RESUMEN

Phosphatidylcholine and phosphatidylethanolamine, the two most abundant phospholipids in mammalian cells, are synthesized de novo by the Kennedy pathway from choline and ethanolamine, respectively1-6. Despite the essential roles of these lipids, the mechanisms that enable the cellular uptake of choline and ethanolamine remain unknown. Here we show that the protein encoded by FLVCR1, whose mutation leads to the neurodegenerative syndrome posterior column ataxia and retinitis pigmentosa7-9, transports extracellular choline and ethanolamine into cells for phosphorylation by downstream kinases to initiate the Kennedy pathway. Structures of FLVCR1 in the presence of choline and ethanolamine reveal that both metabolites bind to a common binding site comprising aromatic and polar residues. Despite binding to a common site, FLVCR1 interacts in different ways with the larger quaternary amine of choline in and with the primary amine of ethanolamine. Structure-guided mutagenesis identified residues that are crucial for the transport of ethanolamine, but dispensable for choline transport, enabling functional separation of the entry points into the two branches of the Kennedy pathway. Altogether, these studies reveal how FLVCR1 is a high-affinity metabolite transporter that serves as the common origin for phospholipid biosynthesis by two branches of the Kennedy pathway.


Asunto(s)
Colina , Etanolamina , Proteínas de Transporte de Membrana , Modelos Moleculares , Humanos , Colina/metabolismo , Sitios de Unión , Etanolamina/metabolismo , Etanolamina/química , Proteínas de Transporte de Membrana/metabolismo , Proteínas de Transporte de Membrana/química , Proteínas de Transporte de Membrana/genética , Fosfatidiletanolaminas/metabolismo , Transporte Biológico , Animales , Fosfatidilcolinas/metabolismo , Fosfatidilcolinas/química , Fosforilación
15.
Int J Mol Sci ; 25(10)2024 May 18.
Artículo en Inglés | MEDLINE | ID: mdl-38791559

RESUMEN

This editorial summarizes the seven scientific papers published in the Special Issue "Overcoming Biological Barriers: Importance of Membrane Transporters in Homeostasis, Disease, and Disease Treatment 2 [...].


Asunto(s)
Homeostasis , Proteínas de Transporte de Membrana , Humanos , Proteínas de Transporte de Membrana/metabolismo , Animales , Transporte Biológico
16.
Int J Mycobacteriol ; 13(1): 7-14, 2024 Jan 01.
Artículo en Inglés | MEDLINE | ID: mdl-38771273

RESUMEN

BACKGROUND: The overexpression of efflux pumps (Eps) was reported to contribute to multidrug resistant tuberculosis (MDR-TB). Increases in Eps that expel structurally unrelated drugs contribute to reduced susceptibility by decreasing the intracellular concentration of antibiotics. In the present study, an association of mycobacterial membrane protein (MmpS5-MmpL5) Ep and its gene regulator (Rv0678) was investigated in MDR-tuberculosis isolates. METHODS: MTB strains were isolated from patients at two different intervals, i.e., once when they had persistent symptoms despite 3-15 ≥ months of treatment and once when they had started new combination therapy ≥2-3 months. Sputum specimens were subjected to Xpert MTB/rifampicin test and then further susceptibility testing using proportional method and multiplex polymerase chain reaction (PCR) were performed on them. The isolates were characterized using both 16S-23S RNA and hsp65 genes spacer (PCR-restriction fragment length polymorphism). Whole-genome sequencing (WGS) was investigated on two isolates from culture-positive specimen per patient. The protein structure was simulated using the SWISS-MODEL. The input format used for this web server was FASTA (amino acid sequence). Protein structure was also analysis using Ramachandran plot. RESULTS: WGS documented deletion, insertion, and substitution in transmembrane transport protein MmpL5 (Rv0676) of Eps. Majority of the studied isolates (n = 12; 92.3%) showed a unique deletion mutation at three positions: (a) from amino acid number 771 (isoleucine) to 776 (valine), (b) from amino acid number 785 (valine) to 793 (histidine), and (c) from amino acid number 798 (leucine) to 806 (glycine)." One isolate (7.6%) had no deletion mutation. In all isolates (n = 13; 100%), a large insertion mutation consisting of 94 amino acid was observed "from amino acid number 846 (isoleucine) to amino acid number 939 (leucine)". Thirty-eight substitutions in Rv0676 were detected, of which 92.3% were identical in the studied isolates. WGS of mycobacterial membrane proteins (MmpS5; Rv0677) and its gene regulator (Rv0678) documented no deletion, insertion, and substitution. No differences were observed between MmpS5-MmpL5 and its gene regulator in isolates that were collected at different intervals. CONCLUSIONS: Significant genetic mutation like insertion, deletion, and substitution within transmembrane transport protein MmpL5 (Rv0676) can change the functional balance of Eps and cause a reduction in drug susceptibility. This is the first report documenting a unique amino acid mutation (insertion and deletion ≥4-94) in Rv0676 among drug-resistant MTB. We suggest the changes in Mmpl5 (Rv0676) might occurred due to in-vivo sub-therapeutic drug stress within the host cell. Changes in MmpL5 are stable and detected through subsequent culture-positive specimens.


Asunto(s)
Antituberculosos , Proteínas Bacterianas , Proteínas de Transporte de Membrana , Pruebas de Sensibilidad Microbiana , Mycobacterium tuberculosis , Tuberculosis Resistente a Múltiples Medicamentos , Humanos , Tuberculosis Resistente a Múltiples Medicamentos/microbiología , Mycobacterium tuberculosis/genética , Mycobacterium tuberculosis/efectos de los fármacos , Proteínas Bacterianas/genética , Proteínas Bacterianas/metabolismo , Proteínas de Transporte de Membrana/genética , Proteínas de Transporte de Membrana/metabolismo , Antituberculosos/farmacología , Farmacorresistencia Bacteriana Múltiple/genética , Secuenciación Completa del Genoma , Esputo/microbiología
17.
Gene ; 916: 148450, 2024 Jul 20.
Artículo en Inglés | MEDLINE | ID: mdl-38588932

RESUMEN

BACKGROUND: Although the implication of receptor of advanced glycation endproducts (RAGE) has been reported in coronary artery disease, its roles in coronary artery ectasia (CAE) have remained undetermined. Furthermore, the effect of RAGE polymorfisms were not well-defined in scope of soluble RAGE (sRAGE) levels. Thus, we aimed to investigate the influence of the functional polymorphisms of RAGE -374T > A (rs1800624) and G82S (rs2070600) in CAE development. METHODS: This prospective observational study was conducted in 2 groups selected of 2452 patients who underwent elective coronary angiography (CAG) for evaluation after positive noninvasive heart tests. Group-I included 98 patients with non-obstructive coronary artery disease and CAE, and Group-II (control) included 100 patients with normal coronary arteries. SNPs were genotyped by real-time PCR using Taqman® genotyping assay. Serum sRAGE and soluble lectin-like oxidized receptor-1 (sOLR1) were assayed by ELISA and serum lipids were measured enzymatically. RESULTS: The frequencies of the RAGE -374A allele and -374AA genotype were significantly higher in CAE patients compared to controls (p < 0.001). sRAGE levels were not different between study groups, while sOLR1 levels were elevated in CAE (p = 0.004). In controls without systemic disease, -374A allele was associated with low sRAGE levels (p < 0.05), but this association was not significant in controls with HT. Similarly, sRAGE levels of CAE patients with both HT and T2DM were higher than those no systemic disease (p = 0.02). The -374A allele was also associated with younger patient age and higher platelet count in the CAE group in both total and subgroup analyses. In the correlation analyses, the -374A allele was also negatively correlated with age and positively correlated with Plt in all of these CAE groups. In the total CAE group, sRAGE levels also showed a positive correlation with age and a negative correlation with HDL-cholesterol levels. On the other hand, a negative correlation was observed between sRAGE and Plt in the total, hypertensive and no systemic disease control subgroups. Multivariate logistic regression analysis confirmed that the -374A allele (p < 0.001), hyperlipidemia (p < 0.05), and high sOLR1 level (p < 0.05) are risk factors for CAE. ROC curve analysis shows that RAGE -374A allele has AUC of 0.713 (sensitivity: 83.7 %, specificity: 59.0 %), which is higher than HLD (sensitivity: 59.2 %, specificity: 69.0 %), HT (sensitivity: 62.4 %, specificity: 61.1 %) and high sOLR1 level (≥0.67 ng/ml)) (sensitivity: 59.8 %, specificity: 58.5 %). CONCLUSION: Beside the demonstration of the relationship between -374A allele and increased risk of CAE for the first time, our results indicate that antihypertensive and antidiabetic treatment in CAE patients causes an increase in sRAGE levels. The lack of an association between the expected -374A allele and low sRAGE levels in total CAE group was attributed to the high proportion of hypertensive patients and hence to antihypertensive treatment. Moreover, the RAGE -374A allele is associated with younger age at CAE and higher Plt, suggesting that -374A may also be associated with platelet activation, which plays a role in the pathogenesis of CAE. However, our data need to be confirmed in a large study for definitive conclusions.


Asunto(s)
Enfermedad de la Arteria Coronaria , Polimorfismo de Nucleótido Simple , Receptor para Productos Finales de Glicación Avanzada , Humanos , Femenino , Masculino , Persona de Mediana Edad , Receptor para Productos Finales de Glicación Avanzada/genética , Receptor para Productos Finales de Glicación Avanzada/sangre , Enfermedad de la Arteria Coronaria/genética , Enfermedad de la Arteria Coronaria/sangre , Estudios Prospectivos , Anciano , Dilatación Patológica/genética , Predisposición Genética a la Enfermedad , Receptores Depuradores de Clase E/genética , Vasos Coronarios/metabolismo , Vasos Coronarios/patología , Estudios de Casos y Controles , Alelos , Angiografía Coronaria , Frecuencia de los Genes , Genotipo , Proteínas Relacionadas con Receptor de LDL , Proteínas de Transporte de Membrana
18.
Curr Biol ; 34(7): R267-R268, 2024 04 08.
Artículo en Inglés | MEDLINE | ID: mdl-38593766

RESUMEN

In this Quick guide, Palmer and Berks introduce the twin-arginine translocation (Tat) systems. Tats are found in a variety of microbes and microbe-derived organelles, and are known to translocate folded substrate proteins across biological membranes.


Asunto(s)
Proteínas de Escherichia coli , Sistema de Translocación de Arginina Gemela , Proteínas de Transporte de Membrana/genética , Proteínas de Transporte de Membrana/metabolismo , Proteínas de Escherichia coli/metabolismo , Sistema de Translocación de Arginina Gemela/metabolismo , Membrana Celular/metabolismo , Arginina/metabolismo , Transporte de Proteínas , Señales de Clasificación de Proteína , Proteínas Bacterianas/metabolismo
19.
Stroke ; 55(6): 1676-1679, 2024 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-38572634

RESUMEN

BACKGROUND: The effects of lipid-lowering drug targets on different ischemic stroke subtypes are not fully understood. We aimed to explore the mechanisms by which lipid-lowering drug targets differentially affect the risk of ischemic stroke subtypes and their underlying pathophysiology. METHODS: Using a 2-sample Mendelian randomization approach, we assessed the effects of genetically proxied low-density lipoprotein cholesterol (LDL-c) and 3 clinically approved LDL-lowering drugs (HMGCR [3-hydroxy-3-methylglutaryl-CoA reductase], PCSK9 [proprotein convertase subtilisin/kexin type 9], and NPC1L1 [Niemann-Pick C1-Like 1]) on stroke subtypes and brain imaging biomarkers associated with small vessel stroke (SVS), including white matter hyperintensity volume and perivascular spaces. RESULTS: In genome-wide Mendelian randomization analyses, lower genetically predicted LDL-c was significantly associated with a reduced risk of any stroke, ischemic stroke, and large artery stroke, supporting previous findings. Significant associations between genetically predicted LDL-c and cardioembolic stroke, SVS, and biomarkers, perivascular space and white matter hyperintensity volume, were not identified in this study. In drug-target Mendelian randomization analysis, genetically proxied reduced LDL-c through NPC1L1 inhibition was associated with lower odds of perivascular space (odds ratio per 1-mg/dL decrease, 0.79 [95% CI, 0.67-0.93]) and with lower odds of SVS (odds ratio, 0.29 [95% CI, 0.10-0.85]). CONCLUSIONS: This study provides supporting evidence of a potentially protective effect of LDL-c lowering through NPC1L1 inhibition on perivascular space and SVS risk, highlighting novel therapeutic targets for SVS.


Asunto(s)
Enfermedades de los Pequeños Vasos Cerebrales , LDL-Colesterol , Accidente Cerebrovascular Isquémico , Análisis de la Aleatorización Mendeliana , Proproteína Convertasa 9 , Humanos , Accidente Cerebrovascular Isquémico/genética , Accidente Cerebrovascular Isquémico/diagnóstico por imagen , LDL-Colesterol/sangre , Enfermedades de los Pequeños Vasos Cerebrales/genética , Enfermedades de los Pequeños Vasos Cerebrales/diagnóstico por imagen , Proproteína Convertasa 9/genética , Biomarcadores/sangre , Proteínas de Transporte de Membrana/genética , Hidroximetilglutaril-CoA Reductasas/genética , Encéfalo/diagnóstico por imagen , Proteínas de la Membrana/genética , Estudio de Asociación del Genoma Completo , Femenino
20.
Toxicol Lett ; 396: 36-47, 2024 May 15.
Artículo en Inglés | MEDLINE | ID: mdl-38663832

RESUMEN

Non-alcoholic fatty liver disease (NAFLD) is one of the most common liver diseases, which can cause serious complications and gradually increase the mortality rate. However, the effects of NAFLD on drug-metabolizing enzymes and transporters remain unclear, which may cause some confusion regarding patient medication. In this study, a NAFLD rat model was constructed by feeding rats with methionine and choline deficiency diets for 6 weeks, and the mRNA and protein levels of drug-metabolizing enzymes and transporter were analyzed by real-time fluorescent quantitative PCR and Western blot, respectively. The activity of drug-metabolizing enzymes was detected by cocktail methods. In the NAFLD rat model, the mRNA expression of phase I enzymes, phase II enzymes, and transporters decreased. At the protein level, only CYP1A1, CYP1B1, CYP2C11, and CYP2J3 presented a decrease. In addition, the activities of CYP1A2, CYP2B1, CYP2C11, CYP2D1, CYP3A2, UGT1A1, UGT1A3, UGT1A6, and UGT1A9 decreased. These changes may be caused by the alteration of FXR, HNF4α, LXRα, LXRß, PXR, and RXR. In conclusion, NAFLD changes the expression and activity of hepatic drug-metabolizing enzymes and transporters in rats, which may affect drug metabolism and pharmacokinetics. In clinical medication, drug monitoring should be strengthened to avoid potential risks.


Asunto(s)
Deficiencia de Colina , Sistema Enzimático del Citocromo P-450 , Hígado , Enfermedad del Hígado Graso no Alcohólico , Ratas Sprague-Dawley , Animales , Enfermedad del Hígado Graso no Alcohólico/metabolismo , Enfermedad del Hígado Graso no Alcohólico/enzimología , Masculino , Hígado/metabolismo , Hígado/enzimología , Sistema Enzimático del Citocromo P-450/metabolismo , Sistema Enzimático del Citocromo P-450/genética , Deficiencia de Colina/complicaciones , Modelos Animales de Enfermedad , ARN Mensajero/metabolismo , ARN Mensajero/genética , Metionina/metabolismo , Ratas , Proteínas de Transporte de Membrana/metabolismo , Proteínas de Transporte de Membrana/genética , Regulación Enzimológica de la Expresión Génica
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