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1.
Brain Nerve ; 71(10): 1071-1079, 2019 Oct.
Artigo em Japonês | MEDLINE | ID: mdl-31588051

RESUMO

Next generation sequencing (NGS) technology has dramatically influenced the field of omics studies, such as genomics and transcriptomics. It is now possible to access a significant number of previously known and novel genomic variants through NGS. Although the effective manipulation and accurate interpretation of the inordinate amount of data may pose a considerable challenge, it enables us to identify specific genes responsible for causing or influencing the susceptibility to a plethora of diseases. Alzheimer's disease (AD) is the most common etiology of dementia in the elderly (approximately 60-70%). The current research trend of AD genetics focuses on the analysis of rare variants (allelic frequency <1%) instead of common variants (allelic frequency >1%) to identify AD-associated genes/variants. A number of genes (such as TREM2, ABCA7, SORL1) that carry rare pathogenic variants have reportedly conferred susceptibility to AD with stronger genetic risk effects (odds ratio >2.0). Here, we are going to introduce a small part of the latest many attractive findings about AD genetic researches.


Assuntos
Doença de Alzheimer/genética , Predisposição Genética para Doença , Transportadores de Cassetes de Ligação de ATP/genética , Alelos , Frequência do Gene , Testes Genéticos , Genômica , Humanos , Proteínas Relacionadas a Receptor de LDL/genética , Glicoproteínas de Membrana/genética , Proteínas de Membrana Transportadoras/genética , Receptores Imunológicos/genética
2.
Adv Exp Med Biol ; 1141: 203-240, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31571166

RESUMO

Transporters play an important role in the absorption, distribution, metabolism, and excretion (ADME) of drugs. In recent years, various in vitro, in situ/ex vivo, and in vivo methods have been established for studying transporter function and drug-transporter interaction. In this chapter, the major types of in vitro models for drug transport studies comprise membrane-based assays, cell-based assays (such as primary cell cultures, immortalized cell lines), and transporter-transfected cell lines with single transporters or multiple transporters. In situ/ex vivo models comprise isolated and perfused organs or tissues. In vivo models comprise transporter gene knockout models, natural mutant animal models, and humanized animal models. This chapter would be focused on the methods for the study of drug transporters in vitro, in situ/ex vivo, and in vivo. The applications, advantages, or limitations of each model and emerging technologies are also mentioned in this chapter.


Assuntos
Proteínas de Membrana Transportadoras , Projetos de Pesquisa , Animais , Transporte Biológico , Linhagem Celular , Interações de Medicamentos , Humanos , Técnicas In Vitro , Projetos de Pesquisa/tendências
3.
Adv Exp Med Biol ; 1141: 293-340, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31571168

RESUMO

Hepatic drug transporters are mainly distributed in parenchymal liver cells (hepatocytes), contributing to drug's liver disposition and elimination. According to their functions, hepatic transporters can be roughly divided into influx and efflux transporters, translocating specific molecules from blood into hepatic cytosol and mediating the excretion of drugs and metabolites from hepatic cytosol to blood or bile, respectively. The function of hepatic transport systems can be affected by interspecies differences and inter-individual variability (polymorphism). In addition, some drugs and disease can redistribute transporters from the cell surface to the intracellular compartments, leading to the changes in the expression and function of transporters. Hepatic drug transporters have been associated with the hepatic toxicity of drugs. Gene polymorphism of transporters and altered transporter expressions and functions due to diseases are found to be susceptible factors for drug-induced liver injury (DILI). In this chapter, the localization of hepatic drug transporters, their regulatory factors, physiological roles, and their roles in drug's liver disposition and DILI are reviewed.


Assuntos
Doença Hepática Induzida por Substâncias e Drogas , Proteínas de Membrana Transportadoras , Preparações Farmacêuticas , Transporte Biológico , Variação Genética , Hepatócitos , Humanos , Proteínas de Membrana Transportadoras/genética , Preparações Farmacêuticas/metabolismo
4.
Adv Exp Med Biol ; 1141: 341-360, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31571169

RESUMO

The kidney plays an important role in maintaining total body homeostasis and eliminating toxic xenobiotics and metabolites. Numerous drugs and their metabolites are ultimately eliminated in the urine. The reabsorption and secretion functions of the nephron are mediated by a variety of transporters located in the basolateral and luminal membranes of the tubular cells. In the past decade, many studies indicated that transporters play important roles in drug pharmacokinetics and demonstrated the impact of renal transporters on the disposition of drugs, drug-drug interactions, and nephrotoxicities. Here, we focus on several important renal transporters and their roles in drug elimination and disposition, drug-induced nephrotoxicities and potential clinical solutions.


Assuntos
Efeitos Colaterais e Reações Adversas Relacionados a Medicamentos , Rim , Proteínas de Membrana Transportadoras , Preparações Farmacêuticas , Animais , Transporte Biológico , Interações de Medicamentos , Humanos , Inativação Metabólica , Rim/efeitos dos fármacos , Preparações Farmacêuticas/metabolismo
5.
Adv Exp Med Biol ; 1141: 361-405, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31571170

RESUMO

Oral drug administration is the most favorable route of drug administration in the clinic. Intestinal transporters have been shown to play a significant role in the rate and extent of drug absorption of some, but not all, drug molecules. Due to the heterogeneous expression of multiple transporters along the intestine, the preferential absorption sites for drugs may vary significantly. In this chapter, we aim to summarize the current research on the expression, localization, function, and regulation of human intestinal transporters implicated in altering the absorption of low to medium molecular weight drug molecules. The role played by bile acid transport proteins (e.g., ASBT and OST-α/ß) is included in the discussion. The synergistic action of intestinal drug metabolism and transport is also discussed. Despite the complicated regulatory factors, the biopharmaceutics drug disposition classification system (BDDCS) put forward by Wu and Benet may help us better predict the effect of transporters on drug absorption. The drug-induced toxicity in the intestine, which may result from drug-drug interaction, gut microbiota, and bile salt toxicity, is also discussed.


Assuntos
Efeitos Colaterais e Reações Adversas Relacionados a Medicamentos , Absorção Intestinal , Intestinos , Proteínas de Membrana Transportadoras , Preparações Farmacêuticas , Interações de Medicamentos , Humanos , Intestinos/efeitos dos fármacos , Preparações Farmacêuticas/metabolismo
6.
Adv Exp Med Biol ; 1141: 407-466, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31571171

RESUMO

Blood-brain interfaces comprise the cerebral microvessel endothelium forming the blood-brain barrier (BBB) and the epithelium of the choroid plexuses forming the blood-cerebrospinal fluid barrier (BCSFB). Their main functions are to impede free diffusion between brain fluids and blood; to provide transport processes for essential nutrients, ions, and metabolic waste products; and to regulate the homeostasis of central nervous system (CNS), all of which are attributed to absent fenestrations, high expression of tight junction proteins at cell-cell contacts, and expression of multiple transporters, receptors, and enzymes. Existence of BBB is an important reason that systemic drug administration is not suitable for the treatment of CNS diseases. Some diseases, such epilepsy, Alzheimer's disease, Parkinson's disease, amyotrophic lateral sclerosis, and diabetes, alter BBB function via affecting tight junction proteins or altering expression and function of these transporters. This chapter will illustrate function of BBB, expression of transporters, as well as their alterations under disease status.


Assuntos
Barreira Hematoencefálica , Proteínas de Membrana Transportadoras , Preparações Farmacêuticas , Transporte Biológico , Barreira Hematoencefálica/metabolismo , Encéfalo/metabolismo , Humanos , Proteínas de Membrana Transportadoras/metabolismo , Preparações Farmacêuticas/administração & dosagem , Preparações Farmacêuticas/metabolismo
7.
Adv Exp Med Biol ; 1141: 467-504, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31571172

RESUMO

Blood-retinal barrier (BRB) includes inner BRB (iBRB) and outer BRB (oBRB), which are formed by retinal capillary endothelial (RCEC) cells and by retinal pigment epithelial (RPE) cells in collaboration with Bruch's membrane and the choriocapillaris, respectively. Functions of the BRB are to regulate fluids and molecular movement between the ocular vascular beds and retinal tissues and to prevent leakage of macromolecules and other potentially harmful agents into the retina, keeping the microenvironment of the retina and retinal neurons. These functions are mainly attributed to absent fenestrations of RCECs, tight junctions, expression of a great diversity of transporters, and coverage of pericytes and glial cells. BRB existence also becomes a reason that systemic administration for some drugs is not suitable for the treatment of retinal diseases. Some diseases (such as diabetes and ischemia-reperfusion) impair BRB function via altering tight junctions, RCEC death, and transporter expression. This chapter will illustrate function of BRB, expressions and functions of these transporters, and their clinical significances.


Assuntos
Barreira Hematorretiniana , Proteínas de Membrana Transportadoras , Expressão Gênica , Humanos , Proteínas de Membrana Transportadoras/genética , Proteínas de Membrana Transportadoras/metabolismo , Retina/metabolismo , Doenças Retinianas/fisiopatologia , Junções Íntimas
8.
Adv Exp Med Biol ; 1141: 505-548, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31571173

RESUMO

The placenta is the only organ linking two different individuals, mother and fetus, termed as blood-placental barrier. The functions of the blood-placental barrier are to regulate material transfer between the maternal and fetal circulation. The main functional units are the chorionic villi within which fetal blood is separated by only three or four cell layers (placental membrane) from maternal blood in the surrounding intervillous space. A series of drug transporters such as P-glycoprotein (P-GP), breast cancer resistance protein (BCRP), multidrug resistance-associated proteins (MRP1, MRP2, MRP3, MRP4, and MRP5), organic anion-transporting polypeptides (OATP4A1, OATP1A2, OATP1B3, and OATP3A1), organic anion transporter 4 (OAT4), organic cation transporter 3 (OCT3), organic cation/carnitine transporters (OCTN1 and OCTN2), multidrug and toxin extrusion 1 (MATE1), and equilibrative nucleoside transporters (ENT1 and ENT2) have been demonstrated on the apical membrane of syncytiotrophoblast, some of which also expressed on the basolateral membrane of syncytiotrophoblast or fetal capillary endothelium. These transporters are involved in transport of most drugs in the placenta, in turn, affecting drug distribution in fetus. Moreover, expressions of these transporters in the placenta often vary along with the gestational ages and are also affected by pathophysiological factor. This chapter will mainly illustrate function and expression of these transporters in placentas, their contribution to drug distribution in fetus, and their clinical significance.


Assuntos
Regulação da Expressão Gênica , Proteínas de Membrana Transportadoras , Placenta , Feminino , Humanos , Proteínas de Membrana Transportadoras/genética , Proteínas de Membrana Transportadoras/metabolismo , Placenta/metabolismo , Gravidez , Distribuição Tecidual , Trofoblastos/metabolismo
9.
N Engl J Med ; 381(17): 1644-1652, 2019 10 24.
Artigo em Inglês | MEDLINE | ID: mdl-31597037

RESUMO

Genome sequencing is often pivotal in the diagnosis of rare diseases, but many of these conditions lack specific treatments. We describe how molecular diagnosis of a rare, fatal neurodegenerative condition led to the rational design, testing, and manufacture of milasen, a splice-modulating antisense oligonucleotide drug tailored to a particular patient. Proof-of-concept experiments in cell lines from the patient served as the basis for launching an "N-of-1" study of milasen within 1 year after first contact with the patient. There were no serious adverse events, and treatment was associated with objective reduction in seizures (determined by electroencephalography and parental reporting). This study offers a possible template for the rapid development of patient-customized treatments. (Funded by Mila's Miracle Foundation and others.).


Assuntos
Proteínas de Membrana Transportadoras/genética , Mutagênese Insercional , Lipofuscinoses Ceroides Neuronais/tratamento farmacológico , Lipofuscinoses Ceroides Neuronais/genética , Oligonucleotídeos Antissenso/uso terapêutico , Medicina de Precisão , Doenças Raras/tratamento farmacológico , Biópsia , Criança , Desenvolvimento Infantil , Descoberta de Drogas , Drogas em Investigação/uso terapêutico , Eletroencefalografia , Feminino , Humanos , Testes Neuropsicológicos , RNA Mensageiro , Convulsões/diagnóstico , Convulsões/tratamento farmacológico , Pele/patologia , Sequenciamento Completo do Genoma
10.
J Agric Food Chem ; 67(38): 10563-10576, 2019 Sep 25.
Artigo em Inglês | MEDLINE | ID: mdl-31487171

RESUMO

Sulfur (S) metabolism plays a vital role in Cd detoxification, but the collaboration between melatonin biosynthesis and S metabolism under Cd stress remains unaddressed. Using exogenous melatonin, melatonin-deficient tomato plants with a silenced caffeic acid O-methyltransferase (COMT) gene, and COMT-overexpressing plants with cosuppression of sulfate transporter (SUT)1 and SUT2 genes, we found that melatonin deficiency decreased S accumulation and aggravated Cd phytotoxicity, whereas exogenous melatonin or overexpression of COMT increased S uptake and assimilation, resulting in an improved plant growth and Cd tolerance. Melatonin deficiency promoted Cd translocation from root to shoot, but COMT overexpression caused the opposite effect. COMT overexpression failed to compensate the functional hierarchy of S when its uptake was inhibited by cosilencing of transporter SUT1 and SUT2. Our study provides genetic evidence that melatonin-mediated tolerance to Cd is closely associated with the efficient regulation of S metabolism, redox homeostasis, and Cd translocation in tomato plants.


Assuntos
Cádmio/metabolismo , Lycopersicon esculentum/metabolismo , Melatonina/metabolismo , Enxofre/metabolismo , Transporte Biológico , Regulação da Expressão Gênica de Plantas , Lycopersicon esculentum/genética , Lycopersicon esculentum/crescimento & desenvolvimento , Proteínas de Membrana Transportadoras/genética , Proteínas de Membrana Transportadoras/metabolismo , Oxirredução , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Proteína O-Metiltransferase/genética , Proteína O-Metiltransferase/metabolismo
11.
Adv Exp Med Biol ; 1155: 3-11, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31468381

RESUMO

Taurine content in an older brain is decreased compared to a younger brain and is associated with cognitive deficits. It is not yet known whether the decrease in taurine content is associated with decreased expression of taurine inflow mediating transporters during the aging process. In this study, we investigated whether aging affects taurine transporter and glycine transporter 1 expression in the brain cortex of the mouse. Taurine and glycine transporter expression was compared in the brain cortex of C57BL/6 mice at different ages (2, 12, and 24 months) and to age-matched NLRP3 inflammasome knockout mice. In wild type mice, taurine transporter (TauT) expression in the brain cortex of 12- or 24-month-old mice did not significantly differ from TauT expression in 2-month-old mice. Moreover, TauT expression in the brain cortex of 12- or 24-month-old mice did not significantly differ from age-matched NLRP3 KO mice. This result indirectly suggests that TauT expression may be not affected by aging or age-induced inflammation. In addition, glycine transporter expression was similar to the TauT expression pattern. In conclusion, aging and age-related inflammation might not significantly affect taurine and glycine transporter expression in aged mice. Thus, the decrease of taurine content in an older brain, which is associated with cognitive deficits, may not be significantly related to altered taurine and glycine transporter expression.


Assuntos
Envelhecimento , Encéfalo/fisiologia , Glicoproteínas de Membrana/fisiologia , Proteínas de Membrana Transportadoras/fisiologia , Taurina/análise , Animais , Camundongos , Camundongos Endogâmicos C57BL
12.
Adv Exp Med Biol ; 1155: 497-505, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31468426

RESUMO

Taurine (2-aminoethanesulfonic acid) is a sulfur-containing organic acid possessing several important effects, including antioxidant and anti-inflammatory ones. Exposure to ionizing radiation generates free radicals and reactive oxygen species (ROS) in irradiated cells, and free radical generation leads to oxidative stress. It is known that radiation nephropathy includes an inflammation-based process in which ROS and cytokines are responsible. Different doses of explored radiation can cause apoptosis, inflammation and a profound oxidative stress in kidneys. Oxidative stress is involved in renal injury after exposure to both ionizing radiation and inflammation. In this review, we describe the protective effect of taurine against several kidney diseases and the potential effects of taurine in the mitigation of radiation nephropathy. We also report that X-irradiation decreased the expression of taurine and TauT in the kidney. Taurine administration suppressed the decrease in the expression of taurine and TauT in the kidney after radiation exposure. Taurine might contribute to the mitigation of kidney injury induced by radiation.


Assuntos
Nefropatias/tratamento farmacológico , Lesões por Radiação/tratamento farmacológico , Taurina/farmacologia , Humanos , Rim/efeitos dos fármacos , Rim/efeitos da radiação , Nefropatias/fisiopatologia , Glicoproteínas de Membrana/metabolismo , Proteínas de Membrana Transportadoras/metabolismo , Estresse Oxidativo , Radiação Ionizante , Espécies Reativas de Oxigênio
13.
Adv Exp Med Biol ; 1155: 543-553, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31468430

RESUMO

Taurine transporter (TauT) has been identified as a target gene of p53 tumor suppressor. TauT is also found to be overexpressed in variety type of human cancers, such as leukemia. This study showed that expression of TauT was upregulated by c-Myc and c-Jun oncogenes. To explore whether blocking of TauT inhibits tumor development, the RNA interference (RNAi) and immune targeting approaches were tested in tumor cells in vitro and in p53 mutant mice in vivo. Knockdown of TauT expression by RNAi resulted in cell cycle G2 arrest and suppressed human breast cancer MCF-7 cells proliferation determined by colonies production and cell migration assays. Knockdown of TauT also rendered MCF-7 cells more susceptible to chemotherapeutic drug-induced apoptosis. An antibody specifically against TauT blocked taurine uptake and induced cell cycle G2 arrest leading to cell death of variety type of tumor cells without affecting the viability of normal mammalian cells. TauT peptide vaccination significantly increased median lifespan (1.5-fold) of the p53 null mice and rescued p53+/- mice by extending the median lifespan from 315 days to 621 days. Furthermore, single dose treatment of tumor-bearing (thymic lymphoma) p53 null mice with TauT peptide reduced tumor size by about 50% and significantly prolonged survival of these mice from average 7 days (after observing the thymic lymphoma) to 21 days. This finding demonstrates that a novel TauT peptide vaccine can delay, inhibit, and/or treat p53 mutation related spontaneous tumorigenesis in vivo. Therefore, TauT peptide may be used as a universal cancer vaccine to prevent and/or treat patients with p53 mutation-mediated cancers.


Assuntos
Vacinas Anticâncer , Imunoterapia , Glicoproteínas de Membrana , Proteínas de Membrana Transportadoras , Interferência de RNA , Proteína Supressora de Tumor p53/genética , Animais , Anticorpos Monoclonais/farmacologia , Pontos de Checagem do Ciclo Celular , Técnicas de Silenciamento de Genes , Genes jun , Genes myc , Humanos , Células MCF-7 , Camundongos , Camundongos Knockout , Terapia de Alvo Molecular , Mutação , Taurina , Vacinas de Subunidades
14.
Bioresour Technol ; 291: 121812, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31376668

RESUMO

In this study, a signal peptide of AlkL was replaced with other signal peptides to improve the soluble expression and thereby facilitate the transport of dodecanoic acid methyl ester (DAME) substrate into the E. coli. Consequently, AlkL with signal peptide FadL (AlkLf) showed higher transport activity toward DAME. Furthermore, the promoter optimization for the efficient heterologous expression of the transporter AlkLf and alkane monooxygenase (AlkBGT) system was conducted and resulted in increased ω-oxygenation activity of AlkBGT system. Moreover, bioinformatic studies led to the identification of novel monooxygenase from Pseudomonas pelagia (Pel), which exhibited 20% higher activity towards DAME as substrate compared to AlkB. Finally, the construction of a chimeric transporter and the expression of newly identified monooxygenase enabled the production of 44.8 ±â€¯7.5 mM of 12-hydroxy dodecanoic acid methyl ester (HADME) and 31.8 ±â€¯1.7 mM of dodecanedioic acid monomethyl ester (DDAME) in a two-phase reaction system.


Assuntos
Proteínas de Membrana Transportadoras , Engenharia Metabólica , Escherichia coli , Oxigenases de Função Mista , Sinais Direcionadores de Proteínas
15.
An Acad Bras Cienc ; 91(3): e20180654, 2019 Jul 29.
Artigo em Inglês | MEDLINE | ID: mdl-31365653

RESUMO

Candida albicans is the most frequent fungal species that causes infections in humans. Fluconazole is the main antifungal used to treat Candida infections, and its prolonged and indiscriminate use for the last decades are the most established causes which originated resistant strains. Fungal drug resistance is associated to alterations in ERG11 gene and overexpression of multidrug resistance (MDR) transporters belonging to two families: ATP-binding cassette (ABC) and Major Facilitator Superfamily (MFS). To evaluate the role of MFS transporters in azoles resistance of C. albicans clinical strains, this study aimed to analyze four Candida albicans clinical isolates from the University Hospital in Juiz de Fora (Minas Gerais/Brazil), selected in our previous study as they were unaffected by FK506, an ABC pumps inhibitor. In a primary investigation on MFS proteins overexpression, the extrusion of fluorescent substrates (rhodamine 6G and nile red) was analyzed by fluorescence microscopy and flow cytometry. Results suggest participation of MFS transporters in azole resistance of C. albicans isolates and indicate the existence of secondary resistance mechanisms. Therefore, this study contributes to the information about Candida albicans infections in Brazil and reinforces the importance of epidemiological studies focusing on an improved understanding of the disease and further resistance reversion.


Assuntos
Antifúngicos/farmacologia , Azóis/farmacologia , Candida albicans/efeitos dos fármacos , Proteínas de Membrana Transportadoras/metabolismo , Azóis/classificação , Transporte Biológico/efeitos dos fármacos , Citometria de Fluxo , Humanos , Proteínas de Membrana Transportadoras/efeitos dos fármacos , Testes de Sensibilidade Microbiana , Microscopia de Fluorescência , Centros de Atenção Terciária
16.
Microb Cell Fact ; 18(1): 116, 2019 Jun 29.
Artigo em Inglês | MEDLINE | ID: mdl-31255177

RESUMO

BACKGROUND: Sucrose is an attractive industrial carbon source due to its abundance and the fact that it can be cheaply generated from sources such as sugarcane. However, only a few characterized Escherichia coli strains are able to metabolize sucrose, and those that can are typically slow growing or pathogenic strains. METHODS: To generate a platform strain capable of efficiently utilizing sucrose with a high growth rate, adaptive laboratory evolution (ALE) was utilized to evolve engineered E. coli K-12 MG1655 strains containing the sucrose utilizing csc genes (cscB, cscK, cscA) alongside the native sucrose consuming E. coli W. RESULTS: Evolved K-12 clones displayed an increase in growth and sucrose uptake rates of 1.72- and 1.40-fold on sugarcane juice as compared to the original engineered strains, respectively, while E. coli W clones showed a 1.4-fold increase in sucrose uptake rate without a significant increase in growth rate. Whole genome sequencing of evolved clones and populations revealed that two genetic regions were frequently mutated in the K-12 strains; the global transcription regulatory genes rpoB and rpoC, and the metabolic region related to a pyrimidine biosynthetic deficiency in K-12 attributed to pyrE expression. These two mutated regions have been characterized to confer a similar benefit when glucose is the main carbon source, and reverse engineering revealed the same causal advantages on M9 sucrose. Additionally, the most prevalent mutation found in the evolved E. coli W lineages was the inactivation of the cscR gene, the transcriptional repression of sucrose uptake genes. CONCLUSION: The generated K-12 and W platform strains, and the specific sets of mutations that enable their phenotypes, are available as valuable tools for sucrose-based industrial bioproduction in the facile E. coli chassis.


Assuntos
Escherichia coli/genética , Escherichia coli/metabolismo , Sacarose/metabolismo , Evolução Molecular Direcionada , Proteínas de Escherichia coli/genética , Proteínas de Escherichia coli/metabolismo , Engenharia Genética , Genoma Bacteriano , Glucose/metabolismo , Proteínas de Membrana Transportadoras/genética , Proteínas de Membrana Transportadoras/metabolismo
17.
BMC Bioinformatics ; 20(Suppl 13): 382, 2019 Jul 24.
Artigo em Inglês | MEDLINE | ID: mdl-31337335

RESUMO

BACKGROUND: Pathogenic protist membrane transporter proteins play important roles not only in exchanging molecules into and out of cells but also in acquiring nutrients and biosynthetic compounds from their hosts. Currently, there is no centralized protist membrane transporter database published, which makes system-wide comparisons and studies of host-pathogen membranomes difficult to achieve. RESULTS: We analyzed over one million protein sequences from 139 protists with full or partial genome sequences. Putative transmembrane proteins were annotated by primary sequence alignments, conserved secondary structural elements, and functional domains. We have constructed the PPTdb (Pathogenic Protist Transmembranome database), a comprehensive membrane transporter protein portal for pathogenic protists and their human hosts. The PPTdb is a web-based database with a user-friendly searching and data querying interface, including hierarchical transporter classification (TC) numbers, protein sequences, functional annotations, conserved functional domains, batch sequence retrieving and downloads. The PPTdb also serves as an analytical platform to provide useful comparison/mining tools, including transmembrane ability evaluation, annotation of unknown proteins, informative visualization charts, and iterative functional mining of host-pathogen transporter proteins. CONCLUSIONS: The PPTdb collected putative protist transporter proteins and offers a user-friendly data retrieving interface. Moreover, a pairwise functional comparison ability can provide useful information for identifying functional uniqueness of each protist. Finally, the host and non-host protein similarity search can fulfill the needs of comprehensive studies of protists and their hosts. The PPTdb is freely accessible at http://pptdb.cgu.edu.tw .


Assuntos
Bases de Dados Factuais , Proteínas de Membrana Transportadoras/análise , Interface Usuário-Computador , Fungos/metabolismo , Humanos , Proteínas de Membrana Transportadoras/genética , Proteínas de Membrana Transportadoras/metabolismo , Plantas/metabolismo
18.
World J Microbiol Biotechnol ; 35(7): 112, 2019 Jul 08.
Artigo em Inglês | MEDLINE | ID: mdl-31286266

RESUMO

Microorganisms have evolved permeases to incorporate various essential nutrients and exclude harmful products, which assists in adaptation to different environmental conditions for survival. As permeases are directly involved in the utilization of and regulatory response to nutrient sources, metabolic engineering of microbial permeases can predictably influence nutrient metabolism and regulation. In this mini-review, we have summarized the mechanisms underlying the general regulation of permeases, and the current advancements and future prospects of metabolic engineering strategies targeting the permeases in Saccharomyces cerevisiae. The different types of permeases and their regulatory mechanisms have been discussed. Furthermore, methods for metabolic engineering of permeases have been highlighted. Understanding the mechanisms via which permeases are meticulously regulated and engineered will not only facilitate research on regulation of global nutrition and yeast metabolic engineering, but can also provide important insights for future studies on the synthesis of valuable products and elimination of harmful substances in S. cerevisiae.


Assuntos
Proteínas de Membrana Transportadoras/metabolismo , Engenharia Metabólica/métodos , Saccharomyces cerevisiae/metabolismo , Transporte Biológico , Carbono/metabolismo , Glucose/metabolismo , Proteínas de Membrana Transportadoras/genética , Nitrogênio/metabolismo , Saccharomyces cerevisiae/genética
19.
Plant Sci ; 286: 57-67, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31300142

RESUMO

Phosphorus in plant cells occurs in inorganic form as both ortho- and pyrophosphate or bound to organic compounds, like e.g., nucleotides, phosphorylated metabolites, phospholipids, phosphorylated proteins, or phytate as P storage in the vacuoles of seeds. Individual compartments of the cell are surrounded by membranes that are selective barriers to avoid uncontrolled solute exchange. A controlled exchange of phosphate or phosphorylated metabolites is accomplished by specific phosphate transporters (PHTs) and the plastidial phosphate translocator family (PTs) of the inner envelope membrane. Plastids, in particular chloroplasts, are the site of various anabolic sequences of enzyme-catalyzed reactions. Apart from their role in metabolism PHTs and PTs are presumed to be also involved in communication between organelles and plant organs. Here we will focus on the integration of phosphate transport and homeostasis in signaling processes. Recent developments in this field will be critically assessed and potential future developments discussed. In particular, the occurrence of various plastid types in one organ (i.e. the leaf) with different functions with respect to metabolism or sensing, as has been documented recently following a tissue-specific proteomics approach (Beltran et al., 2018), will shed new light on functional aspects of phosphate homeostasis.


Assuntos
Homeostase , Proteínas de Membrana Transportadoras/metabolismo , Fosfatos/metabolismo , Células Vegetais/fisiologia , Proteínas de Plantas/metabolismo , Citoplasma/fisiologia , Família Multigênica , Plastídeos/metabolismo , Transdução de Sinais
20.
Microbiol Res ; 226: 48-54, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31284944

RESUMO

The Burkholderia pseudomallei complex consists of six phylogenetically related Gram-negative bacterial species that include environmental saprophytes and mammalian pathogens. These microbes possess multiple type VI secretion systems (T6SS) that provide a fitness advantage in diverse niches by translocating effector molecules into prokaryotic and eukaryotic cells in a contact-dependent manner. Several recent studies have elucidated the regulation and function of T6SS-2, a novel contact-independent member of the T6SS family. Expression of the T6SS-2 gene cluster is repressed by OxyR, Zur and TctR and is activated by GvmR and reactive oxygen species (ROS). The last two genes of the T6SS-2 gene cluster encode a zincophore (TseZ) and a manganeseophore (TseM) that are exported into the extracellular milieu in a contact-independent fashion when microbes encounter oxidative stress. TseZ and TseM bind Zn2+ and Mn2+, respectively, and deliver them to bacteria where they provide protection against the lethal effects of ROS. The TonB-dependent transporters that interact with TseZ and TseM, and actively transport Zn2+ and Mn2+ across the outer membrane, have also been identified. Finally, T6SS-2 provides a contact-independent growth advantage in nutrient limited environments and is critical for virulence in Galleria mellonella larvae, but is dispensable for virulence in rodent models of infection.


Assuntos
Proteínas de Bactérias/genética , Burkholderia pseudomallei/genética , Burkholderia pseudomallei/metabolismo , Manganês/metabolismo , Sistemas de Secreção Tipo VI/genética , Sistemas de Secreção Tipo VI/metabolismo , Zinco/metabolismo , Animais , Proteínas de Bactérias/metabolismo , Burkholderia pseudomallei/classificação , Regulação Bacteriana da Expressão Gênica , Genes Reguladores/genética , Homeostase , Larva , Proteínas de Membrana Transportadoras/genética , Metiltransferases , Família Multigênica , Oxirredução , Estresse Oxidativo , Espécies Reativas de Oxigênio/metabolismo , Virulência/genética
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