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1.
Nat Commun ; 12(1): 5254, 2021 09 06.
Artigo em Inglês | MEDLINE | ID: mdl-34489436

RESUMO

Pdr5, a member of the extensive ABC transporter superfamily, is representative of a clinically relevant subgroup involved in pleiotropic drug resistance. Pdr5 and its homologues drive drug efflux through uncoupled hydrolysis of nucleotides, enabling organisms such as baker's yeast and pathogenic fungi to survive in the presence of chemically diverse antifungal agents. Here, we present the molecular structure of Pdr5 solved with single particle cryo-EM, revealing details of an ATP-driven conformational cycle, which mechanically drives drug translocation through an amphipathic channel, and a clamping switch within a conserved linker loop that acts as a nucleotide sensor. One half of the transporter remains nearly invariant throughout the cycle, while its partner undergoes changes that are transmitted across inter-domain interfaces to support a peristaltic motion of the pumped molecule. The efflux model proposed here rationalises the pleiotropic impact of Pdr5 and opens new avenues for the development of effective antifungal compounds.


Assuntos
Transportadores de Cassetes de Ligação de ATP/química , Transportadores de Cassetes de Ligação de ATP/metabolismo , Proteínas de Saccharomyces cerevisiae/química , Proteínas de Saccharomyces cerevisiae/metabolismo , Transportadores de Cassetes de Ligação de ATP/genética , Trifosfato de Adenosina/metabolismo , Domínio Catalítico , Microscopia Crioeletrônica , Detergentes/química , Farmacorresistência Fúngica/genética , Pleiotropia Genética , Hidrólise , Mutação , Conformação Proteica , Domínios Proteicos , Rodaminas/química , Rodaminas/metabolismo , Proteínas de Saccharomyces cerevisiae/genética , Vanadatos/química , Vanadatos/metabolismo
2.
Nat Commun ; 12(1): 4687, 2021 08 03.
Artigo em Inglês | MEDLINE | ID: mdl-34344901

RESUMO

Lipoproteins are important for bacterial growth and antibiotic resistance. These proteins use lipid acyl chains attached to the N-terminal cysteine residue to anchor on the outer surface of cytoplasmic membrane. In Gram-negative bacteria, many lipoproteins are transported to the outer membrane (OM), a process dependent on the ATP-binding cassette (ABC) transporter LolCDE which extracts the OM-targeted lipoproteins from the cytoplasmic membrane. Lipid-anchored proteins pose a unique challenge for transport machinery as they have both hydrophobic lipid moieties and soluble protein component, and the underlying mechanism is poorly understood. Here we determined the cryo-EM structures of nanodisc-embedded LolCDE in the nucleotide-free and nucleotide-bound states at 3.8-Å and 3.5-Å resolution, respectively. The structural analyses, together with biochemical and mutagenesis studies, uncover how LolCDE recognizes its substrate by interacting with the lipid and N-terminal peptide moieties of the lipoprotein, and identify the amide-linked acyl chain as the key element for LolCDE interaction. Upon nucleotide binding, the transmembrane helices and the periplasmic domains of LolCDE undergo large-scale, asymmetric movements, resulting in extrusion of the captured lipoprotein. Comparison of LolCDE and MacB reveals the conserved mechanism of type VII ABC transporters and emphasizes the unique properties of LolCDE as a molecule extruder of triacylated lipoproteins.


Assuntos
Transportadores de Cassetes de Ligação de ATP/metabolismo , Proteínas da Membrana Bacteriana Externa/metabolismo , Lipoproteínas/metabolismo , Transportadores de Cassetes de Ligação de ATP/química , Transportadores de Cassetes de Ligação de ATP/genética , Acilação , Trifosfato de Adenosina/metabolismo , Proteínas da Membrana Bacteriana Externa/química , Proteínas da Membrana Bacteriana Externa/genética , Sítios de Ligação , Membrana Celular/metabolismo , Microscopia Crioeletrônica , Escherichia coli/genética , Escherichia coli/metabolismo , Interações Hidrofóbicas e Hidrofílicas , Mutação , Periplasma/metabolismo , Conformação Proteica , Transporte Proteico
3.
Int J Mol Sci ; 22(15)2021 Jul 26.
Artigo em Inglês | MEDLINE | ID: mdl-34360754

RESUMO

Peroxisome abundance is regulated by homeostasis between the peroxisomal biogenesis and degradation processes. Peroxin 16 (PEX16) is a peroxisomal protein involved in trafficking membrane proteins for de novo peroxisome biogenesis. The present study demonstrates that PEX16 also modulates peroxisome abundance through pexophagic degradation. PEX16 knockdown in human retinal pigment epithelial-1 cells decreased peroxisome abundance and function, represented by reductions in the expression of peroxisome membrane protein ABCD3 and the levels of cholesterol and plasmalogens, respectively. The activation of pexophagy under PEX16 knockdown was shown by (i) abrogated peroxisome loss under PEX16 knockdown in autophagy-deficient ATG5 knockout cell lines, and (ii) increased autophagy flux and co-localization of p62-an autophagy adaptor protein-with ABCD3 in the presence of the autophagy inhibitor chloroquine. However, the levels of cholesterol and plasmalogens did not recover despite the restoration of peroxisome abundance following chloroquine treatment. Thus, PEX16 is indispensable for maintaining peroxisome homeostasis by regulating not only the commonly known biogenesis pathway but also the autophagic degradation of peroxisomes.


Assuntos
Autofagia , Técnicas de Silenciamento de Genes , Proteínas de Membrana/deficiência , Peroxissomos/metabolismo , Epitélio Pigmentado da Retina/metabolismo , Transportadores de Cassetes de Ligação de ATP/genética , Transportadores de Cassetes de Ligação de ATP/metabolismo , Proteína 5 Relacionada à Autofagia/genética , Proteína 5 Relacionada à Autofagia/metabolismo , Linhagem Celular , Humanos , Proteínas de Membrana/metabolismo , Peroxissomos/genética
4.
Methods Mol Biol ; 2342: 193-234, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34272696

RESUMO

Drug transporters are integral membrane proteins that play a critical role in drug disposition by affecting absorption, distribution, and excretion. They translocate drugs, as well as endogenous molecules and toxins, across membranes using ATP hydrolysis, or ion/concentration gradients. In general, drug transporters are expressed ubiquitously, but they function in drug disposition by being concentrated in tissues such as the intestine, the kidneys, the liver, and the brain. Based on their primary sequence and their mechanism, transporters can be divided into the ATP-binding cassette (ABC), solute-linked carrier (SLC), and the solute carrier organic anion (SLCO) superfamilies. Many X-ray crystallography and cryo-electron microscopy (cryo-EM) structures have been solved in the ABC and SLC transporter superfamilies or of their bacterial homologs. The structures have provided valuable insight into the structural basis of transport. This chapter will provide particular focus on the promiscuous drug transporters because of their effect on drug disposition and the challenges associated with them.


Assuntos
Transportadores de Cassetes de Ligação de ATP/química , Transportadores de Ânions Orgânicos/metabolismo , Proteínas Carreadoras de Solutos/química , Transportadores de Cassetes de Ligação de ATP/metabolismo , Animais , Microscopia Crioeletrônica , Cristalografia por Raios X , Humanos , Modelos Moleculares , Transportadores de Ânions Orgânicos/química , Conformação Proteica , Proteínas Carreadoras de Solutos/metabolismo , Especificidade por Substrato
5.
Int J Mol Sci ; 22(13)2021 Jun 23.
Artigo em Inglês | MEDLINE | ID: mdl-34201488

RESUMO

Chronic obstructive pulmonary disease (COPD) ranks among the leading causes of morbidity and mortality worldwide. COPD rarely occurs in isolation and is often combined with various diseases. It is considered that systemic inflammation underlies the comorbid course of COPD. The data obtained in recent years have shown the importance of violations of the cross-links of lipid metabolism and the immune response, which are links in the pathogenesis of both COPD and atherosclerosis. The role of lipid metabolism disorders in the pathogenesis of the comorbid course of COPD and atherosclerosis and the participation of ATP-binding cassette (ABC) transporters in these processes is discussed in this article. It is known that about 20 representatives of a large family of ABC transporters provide lipid homeostasis of cells by moving lipids inside the cell and in its plasma membrane, as well as removing lipids from the cell. It was shown that some representatives of the ABC-transporter family are involved in various links of the pathogenesis of COPD and atherosclerosis, which can determine their comorbid course.


Assuntos
Transportadores de Cassetes de Ligação de ATP/metabolismo , Aterosclerose/metabolismo , Metabolismo dos Lipídeos , Doença Pulmonar Obstrutiva Crônica/metabolismo , Animais , Aterosclerose/epidemiologia , Comorbidade , Humanos , Doença Pulmonar Obstrutiva Crônica/epidemiologia
6.
Int J Mol Sci ; 22(12)2021 Jun 18.
Artigo em Inglês | MEDLINE | ID: mdl-34207256

RESUMO

ATP-binding cassette (ABC) transporter proteins are a gene super-family in plants and play vital roles in growth, development, and response to abiotic and biotic stresses. The ABC transporters have been identified in crop plants such as rice and buckwheat, but little is known about them in soybean. Soybean is an important oil crop and is one of the five major crops in the world. In this study, 255 ABC genes that putatively encode ABC transporters were identified from soybean through bioinformatics and then categorized into eight subfamilies, including 7 ABCAs, 52 ABCBs, 48 ABCCs, 5 ABCDs, 1 ABCEs, 10 ABCFs, 111 ABCGs, and 21 ABCIs. Their phylogenetic relationships, gene structure, and gene expression profiles were characterized. Segmental duplication was the main reason for the expansion of the GmABC genes. Ka/Ks analysis suggested that intense purifying selection was accompanied by the evolution of GmABC genes. The genome-wide collinearity of soybean with other species showed that GmABCs were relatively conserved and that collinear ABCs between species may have originated from the same ancestor. Gene expression analysis of GmABCs revealed the distinct expression pattern in different tissues and diverse developmental stages. The candidate genes GmABCB23, GmABCB25, GmABCB48, GmABCB52, GmABCI1, GmABCI5, and GmABCI13 were responsive to Al toxicity. This work on the GmABC gene family provides useful information for future studies on ABC transporters in soybean and potential targets for the cultivation of new germplasm resources of aluminum-tolerant soybean.


Assuntos
Transportadores de Cassetes de Ligação de ATP/metabolismo , Alumínio/toxicidade , Proteínas de Plantas/metabolismo , Soja/genética , Transportadores de Cassetes de Ligação de ATP/genética , Resistência a Medicamentos/genética , Proteínas de Plantas/genética , Soja/efeitos dos fármacos , Soja/metabolismo
7.
Molecules ; 26(12)2021 Jun 09.
Artigo em Inglês | MEDLINE | ID: mdl-34207619

RESUMO

Trypanosoma cruzi is the etiologic agent for Chagas disease, which affects 6-7 million people worldwide. The biological diversity of the parasite reflects on inefficiency of benznidazole, which is a first choice chemotherapy, on chronic patients. ABC transporters that extrude xenobiotics, metabolites, and mediators are overexpressed in resistant cells and contribute to chemotherapy failure. An ABCC-like transport was identified in the Y strain and extrudes thiol-conjugated compounds. As thiols represent a line of defense towards reactive species, we aimed to verify whether ABCC-like transport could participate in the regulation of responses to stressor stimuli. In order to achieve this, ABCC-like activity was measured by flow cytometry using fluorescent substrates. The present study reveals the participation of glutathione and ceramides on ABCC-like transport, which are both implicated in stress. Hemin modulated the ABCC-like efflux which suggests that this protein might be involved in cellular detoxification. Additionally, all strains evaluated exhibited ABCC-like activity, while no ABCB1-like activity was detected. Results suggest that ABCC-like efflux is not associated with natural resistance to benznidazole, since sensitive strains showed higher activity than the resistant ones. Although benznidazole is not a direct substrate, ABCC-like efflux increased after prolonged drug exposure and this indicates that the ABCC-like efflux mediated protection against cell stress depends on the glutathione biosynthesis pathway.


Assuntos
Transportadores de Cassetes de Ligação de ATP/metabolismo , Doença de Chagas/tratamento farmacológico , Glutationa/metabolismo , Nitroimidazóis/farmacologia , Trypanosoma cruzi/efeitos dos fármacos , Animais , Transporte Biológico , Doença de Chagas/parasitologia , Resistência a Medicamentos , Estresse Oxidativo/fisiologia , Tripanossomicidas/farmacologia , Trypanosoma cruzi/metabolismo
8.
Int J Mol Sci ; 22(13)2021 Jul 05.
Artigo em Inglês | MEDLINE | ID: mdl-34281263

RESUMO

Cholesterol is a foundational molecule of biology. There is a long-standing interest in understanding how cholesterol metabolism is intertwined with cancer biology. In this review, we focus on the known connections between lung cancer and molecules mediating cholesterol efflux. A major take-home lesson is that the roles of many cholesterol efflux factors remain underexplored. It is our hope that this article would motivate others to investigate how cholesterol efflux factors contribute to lung cancer biology.


Assuntos
Transportadores de Cassetes de Ligação de ATP/metabolismo , Colesterol/metabolismo , Neoplasias Pulmonares/metabolismo , Transportador 1 de Cassete de Ligação de ATP/genética , Transportador 1 de Cassete de Ligação de ATP/metabolismo , Membro 1 da Subfamília G de Transportadores de Cassetes de Ligação de ATP/genética , Membro 1 da Subfamília G de Transportadores de Cassetes de Ligação de ATP/metabolismo , Transportadores de Cassetes de Ligação de ATP/genética , Animais , Apolipoproteína A-I/genética , Apolipoproteína A-I/metabolismo , Transporte Biológico Ativo , Humanos , Proteínas Relacionadas a Receptor de LDL/genética , Proteínas Relacionadas a Receptor de LDL/metabolismo , Neoplasias Pulmonares/genética , Neoplasias Pulmonares/terapia , MicroRNAs/genética , MicroRNAs/metabolismo , Modelos Biológicos
9.
Int J Mol Sci ; 22(11)2021 May 22.
Artigo em Inglês | MEDLINE | ID: mdl-34067346

RESUMO

Prenylated flavonoids are an important class of naturally occurring flavonoids with important biological activity, but their low abundance in nature limits their application in medicines. Here, we showed the hemisynthesis and the determination of various biological activities of seven prenylated flavonoids, named 7-13, with an emphasis on antimicrobial ones. Compounds 9, 11, and 12 showed inhibitory activity against human pathogenic fungi. Compounds 11, 12 (flavanones) and 13 (isoflavone) were the most active against clinical isolated Staphylococcus aureus MRSA, showing that structural requirements as prenylation at position C-6 or C-8 and OH at positions C-5, 7, and 4' are key to the antibacterial activity. The combination of 11 or 12 with commercial antibiotics synergistically enhanced the antibacterial activity of vancomycin, ciprofloxacin, and methicillin in a factor of 10 to 100 times against drug-resistant bacteria. Compound 11 combined with ciprofloxacin was able to decrease the levels of ROS generated by ciprofloxacin. According to docking results of S enantiomer of 11 with ATP-binding cassette transporter showed the most favorable binding energy; however, more studies are needed to support this result.


Assuntos
Antibacterianos/farmacologia , Flavonoides/farmacologia , Prenilação/fisiologia , Transportadores de Cassetes de Ligação de ATP/metabolismo , Animais , Linhagem Celular , Linhagem Celular Tumoral , Simulação por Computador , Flavanonas/farmacologia , Fungos/efeitos dos fármacos , Humanos , Isoflavonas/farmacologia , Camundongos , Testes de Sensibilidade Microbiana/métodos , Espécies Reativas de Oxigênio/metabolismo , Staphylococcus aureus/efeitos dos fármacos
10.
Molecules ; 26(11)2021 May 23.
Artigo em Inglês | MEDLINE | ID: mdl-34071039

RESUMO

ABCG2 is an ABC membrane protein reverse transport pump, which removes toxic substances such as medicines out of cells. As a result, drug bioavailability is an unexpected change and negatively influences the ADMET (absorption, distribution, metabolism, excretion, and toxicity), leading to multi-drug resistance (MDR). Currently, in spite of promising studies, screening for ABCG2 inhibitors showed modest results. The aim of this study was to search for small molecules that could inhibit the ABCG2 pump. We first used the WISS MODEL automatic server to build up ABCG2 homology protein from 655 amino acids. Pharmacophore models, which were con-structed based on strong ABCG2 inhibitors (IC50 < 1 µM), consist of two hydrophobic (Hyd) groups, two hydrogen bonding acceptors (Acc2), and an aromatic or conjugated ring (Aro|PiR). Using molecular docking method, 714 substances from the DrugBank and 837 substances from the TCM with potential to inhibit the ABCG2 were obtained. These chemicals maybe favor synthesized or extracted and bioactivity testing.


Assuntos
Membro 2 da Subfamília G de Transportadores de Cassetes de Ligação de ATP/antagonistas & inibidores , Membro 2 da Subfamília G de Transportadores de Cassetes de Ligação de ATP/química , Transportadores de Cassetes de Ligação de ATP/antagonistas & inibidores , Transportadores de Cassetes de Ligação de ATP/química , Transportadores de Cassetes de Ligação de ATP/metabolismo , Resistência a Múltiplos Medicamentos/fisiologia , Humanos , Ligação de Hidrogênio , Interações Hidrofóbicas e Hidrofílicas , Modelos Moleculares , Simulação de Acoplamento Molecular/métodos , Simulação de Dinâmica Molecular , Ligação Proteica/efeitos dos fármacos , Bibliotecas de Moléculas Pequenas/farmacologia , Relação Estrutura-Atividade
11.
Nat Commun ; 12(1): 3577, 2021 06 11.
Artigo em Inglês | MEDLINE | ID: mdl-34117249

RESUMO

Target protection proteins confer resistance to the host organism by directly binding to the antibiotic target. One class of such proteins are the antibiotic resistance (ARE) ATP-binding cassette (ABC) proteins of the F-subtype (ARE-ABCFs), which are widely distributed throughout Gram-positive bacteria and bind the ribosome to alleviate translational inhibition from antibiotics that target the large ribosomal subunit. Here, we present single-particle cryo-EM structures of ARE-ABCF-ribosome complexes from three Gram-positive pathogens: Enterococcus faecalis LsaA, Staphylococcus haemolyticus VgaALC and Listeria monocytogenes VgaL. Supported by extensive mutagenesis analysis, these structures enable a general model for antibiotic resistance mediated by these ARE-ABCFs to be proposed. In this model, ABCF binding to the antibiotic-stalled ribosome mediates antibiotic release via mechanistically diverse long-range conformational relays that converge on a few conserved ribosomal RNA nucleotides located at the peptidyltransferase center. These insights are important for the future development of antibiotics that overcome such target protection resistance mechanisms.


Assuntos
Antibacterianos/farmacologia , Diterpenos/farmacologia , Farmacorresistência Bacteriana/efeitos dos fármacos , Bactérias Gram-Positivas/efeitos dos fármacos , Lincosamidas/farmacologia , Compostos Policíclicos/farmacologia , Estreptograminas/farmacologia , Transportadores de Cassetes de Ligação de ATP/química , Transportadores de Cassetes de Ligação de ATP/genética , Transportadores de Cassetes de Ligação de ATP/metabolismo , Adesinas Bacterianas/química , Adesinas Bacterianas/genética , Proteínas de Bactérias/química , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Sítios de Ligação , Microscopia Crioeletrônica , Farmacorresistência Bacteriana/genética , Bactérias Gram-Positivas/genética , Modelos Moleculares , Peptidil Transferases/metabolismo , Conformação Proteica , RNA Mensageiro , Ribossomos/metabolismo
12.
Int J Biol Macromol ; 185: 324-337, 2021 Aug 31.
Artigo em Inglês | MEDLINE | ID: mdl-34171249

RESUMO

Mycobacterium tuberculosis, one of the major threats to mankind, requires micronutrients like metal ions for their survival and pathogenicity inside the host system. Intracellular pathogens such as M. tuberculosis have co-evolved to combat the nutritional immunity developed by the host. It has developed eminent mechanisms to sequester essential metal ions from the host system. One such prominent mechanism to scavenge metal ions to thrive in the host cell involves ATP-binding cassette (ABC) transporters, which transport metal ions (in free and/or complex forms) across the cell membrane. This study employs a high-throughput data mining analysis to identify open reading frames (ORFs) encoding metal uptake ABC transporters in M. tuberculosis H37Rv. In total, 19 ORFs resulting in seven ABC transport systems and two P-type ATPases were identified, which are potentially involved in the uptake of different metal ions. The results also suggest the existence of a subunit sharing mechanism in M. tuberculosis where the transmembrane and nucleotide binding domains are shared among different ABC transport systems indicating the import of multiple substrates via a single ABC transporter. Thus, this study reflects an overview of the repertoire of metal-specific ABC transport systems in M. tuberculosis H37Rv, providing potential therapeutic targets for the future.


Assuntos
Transportadores de Cassetes de Ligação de ATP/genética , Transportadores de Cassetes de Ligação de ATP/metabolismo , Metais/metabolismo , Mycobacterium tuberculosis/metabolismo , Transportadores de Cassetes de Ligação de ATP/química , Proteínas de Bactérias/química , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Transporte Biológico , Domínio Catalítico , Mineração de Dados , Ligantes , Modelos Moleculares , Simulação de Acoplamento Molecular , Mycobacterium tuberculosis/genética , Fases de Leitura Aberta , Conformação Proteica
13.
Int J Mol Sci ; 22(10)2021 May 19.
Artigo em Inglês | MEDLINE | ID: mdl-34069640

RESUMO

Bacteria have evolved an array of mechanisms enabling them to resist the inhibitory effect of antibiotics, a significant proportion of which target the ribosome. Indeed, resistance mechanisms have been identified for nearly every antibiotic that is currently used in clinical practice. With the ever-increasing list of multi-drug-resistant pathogens and very few novel antibiotics in the pharmaceutical pipeline, treatable infections are likely to become life-threatening once again. Most of the prevalent resistance mechanisms are well understood and their clinical significance is recognized. In contrast, ribosome protection protein-mediated resistance has flown under the radar for a long time and has been considered a minor factor in the clinical setting. Not until the recent discovery of the ATP-binding cassette family F protein-mediated resistance in an extensive list of human pathogens has the significance of ribosome protection proteins been truly appreciated. Understanding the underlying resistance mechanism has the potential to guide the development of novel therapeutic approaches to evade or overcome the resistance. In this review, we discuss the latest developments regarding ribosome protection proteins focusing on the current antimicrobial arsenal and pharmaceutical pipeline as well as potential implications for the future of fighting bacterial infections in the time of "superbugs."


Assuntos
Resistência Microbiana a Medicamentos/fisiologia , Proteínas Ribossômicas/metabolismo , Ribossomos/metabolismo , Transportadores de Cassetes de Ligação de ATP/metabolismo , Antibacterianos/farmacologia , Bactérias/efeitos dos fármacos , Infecções Bacterianas/tratamento farmacológico , Proteínas de Bactérias/metabolismo , Farmacorresistência Bacteriana/efeitos dos fármacos , Resistência a Múltiplos Medicamentos/efeitos dos fármacos , Modelos Moleculares , Biossíntese de Proteínas/efeitos dos fármacos , Proteínas Ribossômicas/efeitos dos fármacos , Ribossomos/efeitos dos fármacos
14.
Nat Commun ; 12(1): 3853, 2021 06 22.
Artigo em Inglês | MEDLINE | ID: mdl-34158497

RESUMO

Human ATP-binding cassette (ABC) subfamily A (ABCA) transporters mediate the transport of various lipid compounds across the membrane. Mutations in human ABCA transporters have been described to cause severe hereditary disorders associated with impaired lipid transport. However, little is known about the mechanistic details of substrate recognition and translocation by ABCA transporters. Here, we present three cryo-EM structures of human ABCA4, a retina-specific ABCA transporter, in distinct functional states at resolutions of 3.3-3.4 Å. In the nucleotide-free state, the two transmembrane domains (TMDs) exhibit a lateral-opening conformation, allowing the lateral entry of substrate from the lipid bilayer. The N-retinylidene-phosphatidylethanolamine (NRPE), the physiological lipid substrate of ABCA4, is sandwiched between the two TMDs in the luminal leaflet and is further stabilized by an extended loop from extracellular domain 1. In the ATP-bound state, the two TMDs display a closed conformation, which precludes the substrate binding. Our study provides a molecular basis to understand the mechanism of ABCA4-mediated NRPE recognition and translocation, and suggests a common 'lateral access and extrusion' mechanism for ABCA-mediated lipid transport.


Assuntos
Transportadores de Cassetes de Ligação de ATP/química , Transportadores de Cassetes de Ligação de ATP/metabolismo , Fosfatidiletanolaminas/metabolismo , Domínios Proteicos , Retinoides/metabolismo , Transportadores de Cassetes de Ligação de ATP/ultraestrutura , Trifosfato de Adenosina/metabolismo , Transporte Biológico , Membrana Celular/metabolismo , Microscopia Crioeletrônica , Humanos , Modelos Moleculares , Fosfolipídeos/metabolismo , Ligação Proteica
15.
Int J Mol Sci ; 22(9)2021 Apr 30.
Artigo em Inglês | MEDLINE | ID: mdl-33946618

RESUMO

Multidrug resistance (MDR) can be a serious complication for the treatment of cancer as well as for microbial and parasitic infections. Dysregulated overexpression of several members of the ATP-binding cassette transporter families have been intimately linked to MDR phenomena. Three paradigm ABC transporter members, ABCB1 (P-gp), ABCC1 (MRP1) and ABCG2 (BCRP) appear to act as brothers in arms in promoting or causing MDR in a variety of therapeutic cancer settings. However, their molecular mechanisms of action, the basis for their broad and overlapping substrate selectivity, remains ill-posed. The rapidly increasing numbers of high-resolution atomic structures from X-ray crystallography or cryo-EM of mammalian ABC multidrug transporters initiated a new era towards a better understanding of structure-function relationships, and for the dynamics and mechanisms driving their transport cycles. In addition, the atomic structures offered new evolutionary perspectives in cases where transport systems have been structurally conserved from bacteria to humans, including the pleiotropic drug resistance (PDR) family in fungal pathogens for which high resolution structures are as yet unavailable. In this review, we will focus the discussion on comparative mechanisms of mammalian ABCG and fungal PDR transporters, owing to their close evolutionary relationships. In fact, the atomic structures of ABCG2 offer excellent models for a better understanding of fungal PDR transporters. Based on comparative structural models of ABCG transporters and fungal PDRs, we propose closely related or even conserved catalytic cycles, thus offering new therapeutic perspectives for preventing MDR in infectious disease settings.


Assuntos
Transportadores de Cassetes de Ligação de ATP/metabolismo , Resistência a Múltiplos Medicamentos , Proteínas Fúngicas/metabolismo , Micoses/tratamento farmacológico , Neoplasias/tratamento farmacológico , Proteínas de Transporte Nucleocitoplasmático/metabolismo , Animais , Antifúngicos/farmacocinética , Antifúngicos/farmacologia , Antineoplásicos/farmacocinética , Antineoplásicos/farmacologia , Farmacorresistência Fúngica Múltipla , Fungos/efeitos dos fármacos , Fungos/metabolismo , Humanos , Micoses/metabolismo , Neoplasias/metabolismo
16.
Commun Biol ; 4(1): 541, 2021 05 10.
Artigo em Inglês | MEDLINE | ID: mdl-33972677

RESUMO

This study aims to understand the mechanistic basis underlying the response of Bifidobacterium to lactulose ingestion in guts of healthy Japanese subjects, with specific focus on a lactulose transporter. An in vitro assay using mutant strains of Bifidobacterium longum subsp. longum 105-A shows that a solute-binding protein with locus tag number BL105A_0502 (termed LT-SBP) is primarily involved in lactulose uptake. By quantifying faecal abundance of LT-SBP orthologues, which is defined by phylogenetic analysis, we find that subjects with 107 to 109 copies of the genes per gram of faeces before lactulose ingestion show a marked increase in Bifidobacterium after ingestion, suggesting the presence of thresholds between responders and non-responders to lactulose. These results help predict the prebiotics-responder and non-responder status and provide an insight into clinical interventions that test the efficacy of prebiotics.


Assuntos
Transportadores de Cassetes de Ligação de ATP/metabolismo , Proteínas de Bactérias/metabolismo , Bifidobacterium/crescimento & desenvolvimento , Fezes/microbiologia , Microbioma Gastrointestinal/efeitos dos fármacos , Trato Gastrointestinal/microbiologia , Lactulose/administração & dosagem , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Bifidobacterium/efeitos dos fármacos , Bifidobacterium/metabolismo , Estudos Transversais , Feminino , Fármacos Gastrointestinais/administração & dosagem , Trato Gastrointestinal/efeitos dos fármacos , Humanos , Pessoa de Meia-Idade , Adulto Jovem
17.
PLoS Comput Biol ; 17(5): e1009023, 2021 05.
Artigo em Inglês | MEDLINE | ID: mdl-34010286

RESUMO

Marine bacterial diversity is immense and believed to be driven in part by trade-offs in metabolic strategies. Here we consider heterotrophs that rely on organic carbon as an energy source and present a molecular-level model of cell metabolism that explains the dichotomy between copiotrophs-which dominate in carbon-rich environments-and oligotrophs-which dominate in carbon-poor environments-as the consequence of trade-offs between nutrient transport systems. While prototypical copiotrophs, like Vibrios, possess numerous phosphotransferase systems (PTS), prototypical oligotrophs, such as SAR11, lack PTS and rely on ATP-binding cassette (ABC) transporters, which use binding proteins. We develop models of both transport systems and use them in proteome allocation problems to predict the optimal nutrient uptake and metabolic strategy as a function of carbon availability. We derive a Michaelis-Menten approximation of ABC transport, analytically demonstrating how the half-saturation concentration is a function of binding protein abundance. We predict that oligotrophs can attain nanomolar half-saturation concentrations using binding proteins with only micromolar dissociation constants and while closely matching transport and metabolic capacities. However, our model predicts that this requires large periplasms and that the slow diffusion of the binding proteins limits uptake. Thus, binding proteins are critical for oligotrophic survival yet severely constrain growth rates. We propose that this trade-off fundamentally shaped the divergent evolution of oligotrophs and copiotrophs.


Assuntos
Bactérias/metabolismo , Modelos Biológicos , Nutrientes/metabolismo , Água do Mar/microbiologia , Transportadores de Cassetes de Ligação de ATP/metabolismo , Transporte Biológico , Cinética
18.
Nat Commun ; 12(1): 2804, 2021 05 14.
Artigo em Inglês | MEDLINE | ID: mdl-33990571

RESUMO

Chemotherapy remains the standard of care for most cancers worldwide, however development of chemoresistance due to the presence of the drug-effluxing ATP binding cassette (ABC) transporters remains a significant problem. The development of safe and effective means to overcome chemoresistance is critical for achieving durable remissions in many cancer patients. We have investigated the energetic demands of ABC transporters in the context of the metabolic adaptations of chemoresistant cancer cells. Here we show that ABC transporters use mitochondrial-derived ATP as a source of energy to efflux drugs out of cancer cells. We further demonstrate that the loss of methylation-controlled J protein (MCJ) (also named DnaJC15), an endogenous negative regulator of mitochondrial respiration, in chemoresistant cancer cells boosts their ability to produce ATP from mitochondria and fuel ABC transporters. We have developed MCJ mimetics that can attenuate mitochondrial respiration and safely overcome chemoresistance in vitro and in vivo. Administration of MCJ mimetics in combination with standard chemotherapeutic drugs could therefore become an alternative strategy for treatment of multiple cancers.


Assuntos
Transportadores de Cassetes de Ligação de ATP/metabolismo , Trifosfato de Adenosina/metabolismo , Resistencia a Medicamentos Antineoplásicos/fisiologia , Mitocôndrias/metabolismo , Animais , Antineoplásicos/farmacocinética , Antineoplásicos/farmacologia , Materiais Biomiméticos/química , Materiais Biomiméticos/farmacologia , Linhagem Celular Tumoral , Respiração Celular/efeitos dos fármacos , Respiração Celular/fisiologia , Doxorrubicina/farmacocinética , Doxorrubicina/farmacologia , Resistência a Múltiplos Medicamentos/fisiologia , Feminino , Proteínas de Choque Térmico HSP40/deficiência , Proteínas de Choque Térmico HSP40/metabolismo , Humanos , Técnicas In Vitro , Camundongos , Camundongos Endogâmicos NOD , Camundongos SCID , Mitocôndrias/efeitos dos fármacos , Neoplasias/tratamento farmacológico , Neoplasias/metabolismo , Consumo de Oxigênio/efeitos dos fármacos
19.
Hum Genet ; 140(8): 1201-1216, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-33978893

RESUMO

Intermediate-sized insertions are one of the structural variants contributing to genome diversity. However, due to technical difficulties in identifying them, their importance in disease pathogenicity and gene expression regulation remains unclear. We used whole-genome sequencing data of 174 Japanese samples to characterize intermediate-sized insertions using a highly-accurate insertion calling method (IMSindel software and joint-call recovery) and obtained a catalogue of 4254 insertions. We constructed an imputation panel comprising of insertions and SNVs from all samples, and conducted imputation of intermediate-sized insertions for 82 publicly-available Japanese samples. Positive Predictive Value of imputation, evaluated using Nanopore long-read sequencing data, was 97%. Subsequent eQTL analysis predicted 128 (~ 3.0%) insertions as causative for gene expression level changes. Enrichment analysis of causal insertions for genome regulatory elements showed significant associations with CTCF-binding sites, super-enhancers, and promoters. Among 17 causal insertions found in the same causal set with GWAS hits, there were insertions associated with changes in expression of cancer-related genes such as BRCA1, ZNF222, and ABCB10. Analysis of insertions sequences revealed that 461 insertions were short tandem duplications frequently found in early-replicating regions of genome. Furthermore, comparison of functional importance of intermediate-sized insertions with that of intermediate-sized deletions detected in the same sample set in our previous study showed that insertions were more frequent in genic regions, and proportion of functional candidates was smaller in insertions. Here, we characterize a high-confidence set of intermediate-sized insertions and indicate their importance in gene expression regulation. Our results emphasize the importance of considering intermediate-sized insertions in trait association studies.


Assuntos
Regulação da Expressão Gênica , Genoma Humano , Mutagênese Insercional , Proteínas de Neoplasias/genética , Neoplasias/genética , Osteoartrite/genética , Transportadores de Cassetes de Ligação de ATP/genética , Transportadores de Cassetes de Ligação de ATP/metabolismo , Proteína BRCA1/genética , Proteína BRCA1/metabolismo , Sequência de Bases , Sítios de Ligação , Fator de Ligação a CCCTC/genética , Fator de Ligação a CCCTC/metabolismo , Mapeamento Cromossômico , Bases de Dados Genéticas , Elementos Facilitadores Genéticos , Perfilação da Expressão Gênica , Humanos , Japão , Anotação de Sequência Molecular , Proteínas de Neoplasias/metabolismo , Neoplasias/metabolismo , Neoplasias/patologia , Osteoartrite/metabolismo , Osteoartrite/patologia , Regiões Promotoras Genéticas , Locos de Características Quantitativas , Proteínas Repressoras/genética , Proteínas Repressoras/metabolismo , Software , Sequenciamento Completo do Genoma
20.
Arch Insect Biochem Physiol ; 107(3): e21794, 2021 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-33948968

RESUMO

Bombyx mori as a representative in Lepidoptera is an important economic insect in agriculture production. Bacillus thuringiensis (Bt) is a bacterial pathogen in silkworm production. Understanding how silkworm respond to Bt-toxin can provide guidance to cultivate resistant silkworm strains. Cry1Ac is one type of Bt-toxin. In current research, Dazao, a susceptible B. mori strain to Bt-toxin, was treated by Cry1Ac toxin and compared its transcriptome with untreated samples. This analysis detected 1234 differentially expressed genes (DEGs). Gene Ontology, KEGG, and UniProt keyword enrichment analysis showed that DEGs include ATP-binding cassette (ABC) transporter, stress response, cuticle, and protein synthesis, and folding process. Five ABC genes were upregulated after Cry1Ac treatment including ABCA2, ABCA3, and ABCC4. They are also known as the transporters of Bt-toxin in lepidopteran insect. Expression of cuticle proteins was significantly increased at 6 h after Cry1Ac treatment. Sex-specific storage-proteins and heat shock protein were also upregulated in Cry1Ac treated samples. Our data provide an expression profile about the response of Cry1Ac toxin in susceptible B. mori strain.


Assuntos
Toxinas de Bacillus thuringiensis/farmacologia , Bombyx/efeitos dos fármacos , Endotoxinas/farmacologia , Proteínas Hemolisinas/farmacologia , Transcriptoma/efeitos dos fármacos , Transportadores de Cassetes de Ligação de ATP/metabolismo , Animais , Bombyx/metabolismo , Proteínas de Choque Térmico/metabolismo , Proteínas de Insetos/metabolismo
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