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1.
Nat Commun ; 10(1): 2765, 2019 06 24.
Artigo em Inglês | MEDLINE | ID: mdl-31235691

RESUMO

G protein-coupled receptors (GPCRs) can integrate extracellular signals via allosteric interactions within dimers and higher-order oligomers. However, the structural bases of these interactions remain unclear. Here, we use the GABAB receptor heterodimer as a model as it forms large complexes in the brain. It is subjected to genetic mutations mainly affecting transmembrane 6 (TM6) and involved in human diseases. By cross-linking, we identify the transmembrane interfaces involved in GABAB1-GABAB2, as well as GABAB1-GABAB1 interactions. Our data are consistent with an oligomer made of a row of GABAB1. We bring evidence that agonist activation induces a concerted rearrangement of the various interfaces. While the GB1-GB2 interface is proposed to involve TM5 in the inactive state, cross-linking of TM6s lead to constitutive activity. These data bring insight for our understanding of the allosteric interaction between GPCRs within oligomers.


Assuntos
Modelos Moleculares , Domínios Proteicos/fisiologia , Multimerização Proteica/fisiologia , Receptores de GABA-B/metabolismo , Regulação Alostérica/efeitos dos fármacos , Regulação Alostérica/fisiologia , Sítio Alostérico/efeitos dos fármacos , Sítio Alostérico/fisiologia , Reagentes para Ligações Cruzadas/química , Agonistas dos Receptores de GABA-B/farmacologia , Células HEK293 , Humanos , Ligação Proteica/efeitos dos fármacos , Ligação Proteica/fisiologia , Domínios Proteicos/efeitos dos fármacos , Multimerização Proteica/efeitos dos fármacos , Ácido gama-Aminobutírico/metabolismo
2.
Inorg Chem ; 58(13): 8800-8819, 2019 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-31247881

RESUMO

Very few inorganic antineoplastic drugs have entered the clinic in the last decades, mainly because of toxicity issues. Because copper is an essential trace element of ubiquitous occurrence, decreased side effects could be expected in comparison with the widely used platinum anticancer compounds. In the present work, two novel hydrazonic binucleating ligands and their µ-hydroxo dicopper(II) complexes were prepared and fully characterized. They differ by the nature of the aromatic group present in their aroylhydrazone moieties: while H3L1 and its complex, 1, possess a thiophene ring, H3L2 and 2 contain the more polar furan heterocycle. X-ray diffraction indicates that both coordination compounds are very similar in structural terms and generate dimeric arrangements in the solid state. Positive-ion electrospray ionization mass spectrometry analyses confirmed that the main species present in a 10% dimethyl sulfoxide (DMSO)/water solution should be [Cu2(HL)(OH)]+ and the DMSO-substituted derivative [Cu2(L)(DMSO)]+. Scattering techniques [dynamic light scattering (DLS) and small-angle X-ray scattering] suggest that the complexes and their free ligands interact with bovine serum albumin (BSA) in a reversible manner. The binding constants to BSA were determined for the complexes through fluorescence spectroscopy. Moreover, to gain insight into the mechanism of action of the compounds, calf thymus DNA binding studies by UV-visible and DLS measurements using plasmid pBR322 DNA were also performed. For the complexes, DLS data seem to point to the occurrence of DNA cleavage to Form III (linear). Both ligands and their dicopper(II) complexes display potent antiproliferative activity in a panel of four cancer cell lines, occasionally even in the submicromolar range, with the complexes being more potent than the free ligands. Our data on cellular models correlate quite well with the DNA interaction experiments. The results presented herein show that aroylhydrazone-derived binucleating ligands, as well as their dinuclear µ-hydroxodicopper(II) complexes, may represent a promising structural starting point for the development of a new generation of highly active potential antitumor agents.


Assuntos
Antineoplásicos/farmacologia , Complexos de Coordenação/farmacologia , Hidrazonas/farmacologia , Animais , Antineoplásicos/síntese química , Antineoplásicos/química , Antineoplásicos/toxicidade , Bovinos , Linhagem Celular Tumoral , Complexos de Coordenação/síntese química , Complexos de Coordenação/química , Complexos de Coordenação/toxicidade , Cobre/química , DNA/química , Clivagem do DNA/efeitos dos fármacos , Cães , Humanos , Hidrazonas/síntese química , Hidrazonas/química , Hidrazonas/toxicidade , Isomerismo , Ligantes , Células Madin Darby de Rim Canino , Camundongos , Plasmídeos/química , Multimerização Proteica/efeitos dos fármacos , Soroalbumina Bovina/metabolismo
3.
Eur J Med Chem ; 177: 247-258, 2019 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-31158742

RESUMO

Alzheimer's disease (AD) is a chronic, fatal and complex neurodegenerative disorder, which is characterized by cholinergic system dysregulation, metal dyshomeostasis, amyloid-ß (Aß) aggregation, etc. Therefore in most cases, single-target or single-functional agents are insufficient to achieve the desirable effect against AD. Multi-Target-Directed Ligand (MTDL), which is rationally designed to simultaneously hit multiple targets to improve the pharmacological profiles, has been developed as a promising approach for drug discovery against AD. To identify the multifunctional agents for AD, we developed an innovative method to successfully conceal the metal chelator into acetylcholinesterase (AChE) inhibitor. Briefly, the "hidden" agents first cross the Blood Brain Barrier (BBB) to inhibit the function of AChE, and the metal chelator will then be released via the enzymatic hydrolysis by AChE. Therefore, the AChE inhibitor, in this case, is not only a single-target agent against AD, but also a carrier of the metal chelator. In this study a total of 14 quinoline derivatives were synthesized and biologically evaluated. Both in vitro and in vivo results demonstrated that compound 9b could cross the BBB efficiently, then release 8a, the metabolite of 9b, into brain. In vitro, 9b had a potent AChE inhibitory activity, while 8a displayed a significant metal ion chelating function, therefore in combination, both 9b and 8a exhibited a considerable inhibition of Aß aggregation, one of the observations that plays important roles in the pathogenesis of AD. The efficacy of 9b against AD was further investigated in both a zebrafish model and two different mice models.


Assuntos
Quelantes/farmacologia , Inibidores da Colinesterase/farmacologia , Nootrópicos/farmacologia , Quinolinas/farmacologia , Acetilcolinesterase/química , Acetilcolinesterase/metabolismo , Peptídeos beta-Amiloides/química , Animais , Barreira Hematoencefálica/metabolismo , Quelantes/síntese química , Quelantes/farmacocinética , Quelantes/toxicidade , Inibidores da Colinesterase/síntese química , Inibidores da Colinesterase/farmacocinética , Inibidores da Colinesterase/toxicidade , Desenho de Drogas , Canal de Potássio ERG1/antagonistas & inibidores , Masculino , Camundongos , Microssomos Hepáticos/metabolismo , Simulação de Acoplamento Molecular , Estrutura Molecular , Nootrópicos/síntese química , Nootrópicos/farmacocinética , Nootrópicos/toxicidade , Fragmentos de Peptídeos/química , Multimerização Proteica/efeitos dos fármacos , Quinolinas/síntese química , Quinolinas/farmacocinética , Quinolinas/toxicidade , Ratos Sprague-Dawley , Relação Estrutura-Atividade , Peixe-Zebra
4.
Eur J Med Chem ; 177: 414-424, 2019 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-31158754

RESUMO

Due to the role of butyrylcholinesterase (BChE) in acetylcholine hydrolysis in the late stages of the Alzheimer's disease (AD), inhibitors of butyrylcholinesterase (BChE) have been recently envisaged, besides acetylcholinesterase (AChE) inhibitors, as candidates for treating mild-to-moderate AD. Herein, synthesis and AChE/BChE inhibition activity of some twenty derivatives of 1,2,3,4,5,6-hexahydroazepino[4,3-b]indole (HHAI) is reported. Most of the newly synthesized HHAI derivatives achieved the inhibition of both ChE isoforms with IC50s in the micromolar range, with a structure-dependent selectivity toward BChE. Apparently, molecular volume and lipophilicity do increase selectivity toward BChE, and indeed the N2-(4-phenylbutyl) HHAI derivative 15d, which behaves as a mixed-type inhibitor, resulted the most potent (IC50 0.17 µM) and selective (>100-fold) inhibitor toward either horse serum and human BChE. Moreover, 15d inhibited in vitro self-induced aggregation of neurotoxic amyloid-ß (Aß) peptide and displayed neuroprotective effects in neuroblastoma SH-SY5Y cell line, significantly recovering (P < 0.001) cell viability when impaired by Aß1-42 and hydrogen peroxide insults. Overall, this study highlighted HHAI as useful and versatile scaffold for developing new small molecules targeting some enzymes and biochemical pathways involved in the pathogenesis of AD.


Assuntos
Azepinas/farmacologia , Inibidores da Colinesterase/farmacologia , Indóis/farmacologia , Fármacos Neuroprotetores/farmacologia , Peptídeos beta-Amiloides/metabolismo , Azepinas/síntese química , Azepinas/química , Azepinas/metabolismo , Butirilcolinesterase/química , Butirilcolinesterase/metabolismo , Domínio Catalítico , Linhagem Celular Tumoral , Inibidores da Colinesterase/síntese química , Inibidores da Colinesterase/química , Inibidores da Colinesterase/metabolismo , Relação Dose-Resposta a Droga , Desenho de Drogas , Depuradores de Radicais Livres/síntese química , Depuradores de Radicais Livres/química , Depuradores de Radicais Livres/metabolismo , Depuradores de Radicais Livres/farmacologia , Humanos , Indóis/síntese química , Indóis/química , Indóis/metabolismo , Simulação de Acoplamento Molecular , Estrutura Molecular , Fármacos Neuroprotetores/síntese química , Fármacos Neuroprotetores/química , Fármacos Neuroprotetores/metabolismo , Fragmentos de Peptídeos/metabolismo , Ligação Proteica/efeitos dos fármacos , Multimerização Proteica/efeitos dos fármacos , Relação Estrutura-Atividade
5.
Nat Commun ; 10(1): 2607, 2019 06 13.
Artigo em Inglês | MEDLINE | ID: mdl-31197133

RESUMO

Inhibiting the RAS oncogenic protein has largely been through targeting the switch regions that interact with signalling effector proteins. Here, we report designed ankyrin repeat proteins (DARPins) macromolecules that specifically inhibit the KRAS isoform by binding to an allosteric site encompassing the region around KRAS-specific residue histidine 95 at the helix α3/loop 7/helix α4 interface. We show that these DARPins specifically inhibit KRAS/effector interactions and the dependent downstream signalling pathways in cancer cells. Binding by the DARPins at that region influences KRAS/effector interactions in different ways, including KRAS nucleotide exchange and inhibiting KRAS dimerization at the plasma membrane. These results highlight the importance of targeting the α3/loop 7/α4 interface, a previously untargeted site in RAS, for specifically inhibiting KRAS function.


Assuntos
Sítio Alostérico/efeitos dos fármacos , Antineoplásicos/farmacologia , Desenho de Drogas , Neoplasias/tratamento farmacológico , Proteínas Proto-Oncogênicas p21(ras)/antagonistas & inibidores , Repetição de Anquirina , Antineoplásicos/uso terapêutico , Linhagem Celular Tumoral , Membrana Celular/efeitos dos fármacos , Membrana Celular/metabolismo , Ensaios de Seleção de Medicamentos Antitumorais , Células HEK293 , Histidina/metabolismo , Humanos , Isoenzimas/antagonistas & inibidores , Isoenzimas/genética , Isoenzimas/metabolismo , Neoplasias/genética , Neoplasias/patologia , Biblioteca de Peptídeos , Ligação Proteica/efeitos dos fármacos , Ligação Proteica/genética , Multimerização Proteica/efeitos dos fármacos , Proteínas Proto-Oncogênicas p21(ras)/genética , Proteínas Proto-Oncogênicas p21(ras)/metabolismo , Transdução de Sinais/efeitos dos fármacos
6.
Eur J Med Chem ; 176: 292-309, 2019 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-31112891

RESUMO

Compounds targeting multiple proteins can have synergistic effects and are therefore of interest in medicinal chemistry. At the same time, inhibiting protein-protein interactions (PPI) is increasingly desired in the treatment of disorders or diseases. The development of non-peptidomimetic inhibitors is still a challenge. Herein we investigate macrocyclic scaffolds with one or two embedded carbohydrates (MECs) that present amino acid side chains, or related isosteres, as pharmacophoric groups. Firstly, retroscreening of the previously reported eannaphane-40 (E40, 40), a MEC presenting two pharmacophoric groups, against a set of 55 receptor-subtypes led to a finding of sub-micromolar inhibitory activity for E40 against three serotonergic isoforms (5HT1A/2A/2B) as well as the Na+ channel and the NK-2 receptor. We synthesised MECs with an additional pharmacophoric group compared to E40, with a view to identifying compounds where the selectivity profile was altered among the protein hits from the retroscreening. MECs were produced based on scaffolds with two monosaccharide residues, leading to the incorporation of a third pharmacophoric group. Later, homology models were prepared for four proteins (5HT1A, 5HT2A, NK2 and site-2 of the sodium channel) whose 3D structure is unknown. Inverse docking of the synthesised compounds led to the selection of a new MEC (MEC-B) for protein binding assays. MEC-B was found to have its selectivity profile modulated, in line with docking prediction, compared to E40. MEC-B is dual inhibitor of both 5-HT1A and the sodium channel with improved selectivity for these proteins compared to 5-HT2A/2B/2C, 5-HT transporter and NK2 receptor. Thus, a new multitargeting compound, with an improved selectivity profile was identified, based on a MEC peptidomimetic scaffold.


Assuntos
Glucosídeos/metabolismo , Compostos Macrocíclicos/metabolismo , Peptidomiméticos/metabolismo , Multimerização Proteica/efeitos dos fármacos , Proteínas/metabolismo , Sequência de Aminoácidos , Animais , Sítios de Ligação , Desenho de Drogas , Escherichia coli , Glucosídeos/síntese química , Glucosídeos/química , Humanos , Ligantes , Compostos Macrocíclicos/síntese química , Compostos Macrocíclicos/química , Simulação de Acoplamento Molecular , Peptidomiméticos/síntese química , Peptidomiméticos/química , Ligação Proteica , Receptores da Neurocinina-2/metabolismo , Receptores de Serotonina/metabolismo , Proteínas da Membrana Plasmática de Transporte de Serotonina/metabolismo , Canais de Sódio/metabolismo
7.
Eur J Med Chem ; 177: 198-211, 2019 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-31136894

RESUMO

A series of 3-amino-substituted rutacecarpine derivatives were synthesized to identify novel multitarget-directed ligands (MTDLs) for the treatment of Alzheimer's disease (AD). Biological evaluation showed that most of the synthesized compounds inhibited butyrylcholinesterase (BuChE) and exerted antioxidant effects. Among the synthesized compounds, 6n was subjected to further biological evaluation. Lineweaver-Burk plotting and molecular modeling illustrated that 6n bound simultaneously to the peripheral anionic site (PAS) and catalytic sites (CAS) of BuChE. Furthermore, 6n modulated Aß aggregation; chelated biometals; presented good absorption, distribution, metabolism, excretion, and toxicity properties; and showed remarkable neuroprotective activity. Previous research has shown that the optimized compound 6n has considerable potential for development as an MTDL for the treatment of AD.


Assuntos
Doença de Alzheimer/tratamento farmacológico , Inibidores da Colinesterase/farmacologia , Substâncias Protetoras/farmacologia , Sulfonamidas/farmacologia , Peptídeos beta-Amiloides/metabolismo , Animais , Butirilcolinesterase/química , Butirilcolinesterase/metabolismo , Linhagem Celular Tumoral , Quelantes/síntese química , Quelantes/química , Quelantes/farmacocinética , Quelantes/farmacologia , Inibidores da Colinesterase/síntese química , Inibidores da Colinesterase/química , Inibidores da Colinesterase/farmacocinética , Desenho de Drogas , Humanos , Ligantes , Simulação de Acoplamento Molecular , Simulação de Dinâmica Molecular , Estrutura Molecular , Substâncias Protetoras/síntese química , Substâncias Protetoras/química , Substâncias Protetoras/farmacocinética , Multimerização Proteica/efeitos dos fármacos , Ratos , Relação Estrutura-Atividade , Sulfonamidas/síntese química , Sulfonamidas/química , Sulfonamidas/farmacocinética
8.
Phytomedicine ; 58: 152770, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-31005716

RESUMO

BACKGROUND: Phenanthrenes isolated from Juncus species possess different biological activities, including antiproliferative and antimigratory effects. PURPOSE: In this study, nine phenanthrenes isolated from the roots of Juncus inflexus were investigated for their antiproliferative activity on several gynecological cancer cell lines, using non-cancerous cells as controls. METHODS: Antiproliferative activities of the compounds were determined by means of MTT assay. Flow cytometry was used for cell cycle analysis and determination of mitotic cells. Activities of caspase-3, -8, and -9 were detected by colorimetric kits. Tubulin polymerization was followed by kinetic absorbance determination. Action on tumor cell migration was described using wound healing assay. Western blot assays were used to determine apoptosis-related factors at protein level. RESULTS: Among the compounds tested, juncusol exhibited the most substantial antiproliferative effect against cervical cancer HeLa cells. It was also revealed that juncusol has a distinct growth inhibitory effect in cervical cancer cell lines of various HPV status: it was highly active in HPV type 18-positive HeLa cells, while it was inactive in HPV type 16-positive SiHa and CaSki cells. Cell cycle analysis showed an increase in G2/M and subG1 cell populations after juncusol treatment. Caspase-3, -8, and -9 were detected to be activated by juncusol in HeLa cells, indicating that juncusol induces apoptotic cell death. Moreover, juncusol inhibited tubulin polymerization, as well as EGFR activation, suggesting two possible additional mechanisms that may account for juncusol's inducing a G2/M-phase cell cycle arrest and inhibiting cell migration. CONCLUSION: These results suggest that juncusol is a potent antiproliferative agent against HPV-18 related cervical cancer and may be considered as a lead compound for the development of innovative anticancer agents.


Assuntos
Antineoplásicos/farmacologia , Apoptose/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Magnoliopsida/química , Fenantrenos/farmacologia , Neoplasias do Colo do Útero/tratamento farmacológico , Antineoplásicos/química , Caspase 3/metabolismo , Caspase 8/metabolismo , Caspase 9/metabolismo , Pontos de Checagem do Ciclo Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Movimento Celular/efeitos dos fármacos , Feminino , Humanos , Fenantrenos/química , Multimerização Proteica/efeitos dos fármacos , Tubulina (Proteína)/metabolismo
9.
Comput Biol Chem ; 80: 168-176, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-30965174

RESUMO

The alarm is rang for friendly fire; Saccharomyces cerevisiae (S. cerevisiae) newfound as a fungal pathogen with an individual feature. S. cerevisiae has food safety and is not capable of producing infection but, when the host defenses are weakened, there is room for opportunistic S. cerevisiae strains to cause a health issues. Fungal diseases are challenging to treat because, unlike bacteria, the fungal are eukaryotes. Antibiotics only target prokaryotic cells, whereas compounds that kill fungi also harm the mammalian host. Small differences between mammalian and fungal cells regarding genes and proteins sequence and function make finding a drug target more challenging. Recently, Chitin synthase has been considered as a promising target for antifungal drug development as it is absent in mammals. In S. cerevisiae, CHS3, a class IV chitin synthase, produces 90% of the chitin and essential for cell growth. CHS3 from the trans-Golgi network to the plasma membrane requires assembly of the exomer complex (including proteins cargo such as CHS5, CHS6, Bach1, and Arf1). In this work, we performed SELEX (Systematic Evolution of Ligands by EXponential enrichment) as high throughput virtual screening of the RCSB data bank to find an aptamer as potential inhibit of the class IV chitin synthase of S. cerevisiae. Among all the candidates, G-rich VEGF (GVEGF) aptamer (PDB code: 2M53) containing locked sugar parts was observed as potential inhibitor of the assembly of CHS5-CHS6 exomer complex a subsequently block the chitin biosynthesis pathway as an effective anti-fungal. It was suggested from the simulation that an assembly of exomer core should begin CHS5-CHS6, not from CHS5-Bach1. It is notable that secondary structures of CHS6 and Bach1 was observed very similar, but they have only 25% identity at the amino acid sequence that exhibited different features in exomer assembly.


Assuntos
Proteínas Adaptadoras de Transporte Vesicular/metabolismo , Aptâmeros de Nucleotídeos/metabolismo , Quitina Sintase/metabolismo , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , Proteínas de Membrana/metabolismo , Multimerização Proteica/efeitos dos fármacos , Proteínas de Saccharomyces cerevisiae/metabolismo , Fator A de Crescimento do Endotélio Vascular/química , Proteínas Adaptadoras de Transporte Vesicular/química , Sequência de Aminoácidos , Antifúngicos/metabolismo , Aptâmeros de Nucleotídeos/genética , Sítios de Ligação , Quitina Sintase/química , Quadruplex G , Peptídeos e Proteínas de Sinalização Intracelular/química , Proteínas de Membrana/química , Simulação de Acoplamento Molecular , Ligação Proteica , Técnica de Seleção de Aptâmeros , Saccharomyces cerevisiae/enzimologia , Proteínas de Saccharomyces cerevisiae/química , Alinhamento de Sequência
10.
Molecules ; 24(7)2019 Mar 31.
Artigo em Inglês | MEDLINE | ID: mdl-30935100

RESUMO

Monoterpenoid indole alkaloids are structurally diverse natural products found in plants of the family Apocynaceae. Among them, vincristine and its derivatives are well known for their anticancer activity. Bousigonia mekongensis, a species in this family, contains various monoterpenoid indole alkaloids. In the current study, fourteen known aspidosperma-type monoterpenoid indole alkaloids (1⁻14) were isolated and identified from a methanol extract of the twigs and leaves of B. mekongensis for the first time. Among them, compounds 3, 6, 9, and 13 exhibited similar antiproliferative activity spectra against A549, KB, and multidrug-resistant (MDR) KB subline KB-VIN cells with IC50 values ranging from 0.5⁻0.9 µM. The above alkaloids efficiently induced cell cycle arrest at the G2/M phase by inhibiting tubulin polymerization as well as mitotic bipolar spindle formation. Computer modeling studies indicated that compound 7 likely forms a hydrogen bond (H-bond) with α- or ß-tubulin at the colchicine site. Evaluation of the antiproliferative effects and SAR analysis suggested that a 14,15-double bond or 3α-acetonyl group is critical for enhanced antiproliferative activity. Mechanism of action studies demonstrated for the first time that compounds 3, 4, 6, 7, and 13 efficiently induce cell cycle arrest at G2/M by inhibiting tubulin polymerization by binding to the colchicine site.


Assuntos
Aspidosperma/química , Multimerização Proteica/efeitos dos fármacos , Alcaloides de Triptamina e Secologanina/química , Alcaloides de Triptamina e Secologanina/farmacologia , Moduladores de Tubulina/química , Moduladores de Tubulina/farmacologia , Tubulina (Proteína)/química , Antineoplásicos/química , Antineoplásicos/farmacologia , Ciclo Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Humanos , Modelos Moleculares , Conformação Molecular , Estrutura Molecular , Ligação Proteica , Relação Estrutura-Atividade , Tubulina (Proteína)/metabolismo
11.
Methods Mol Biol ; 1957: 83-91, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30919348

RESUMO

Initially identified as monomers, G protein-coupled receptors (GPCRs) can also form functional dimers that act as distinct signalling hubs for the integration of cellular signalling. We previously found that the angiotensin II (Ang II) type 1 receptor (AT1R) and the prostaglandin F2α (PGF2α) receptor (FP), both important in the control of smooth muscle contractility, form such a functional heterodimeric complex in HEK 293 and vascular smooth muscle cells (Goupil et al., J Biol Chem 290:3137-3148, 2015; Sleno et al., J Biol Chem 292:12139-12152, 2017). In addition to canonical G protein coupling, GPCRs recruit and engage ß-arrestin-dependent pathways. Using BRET-based biosensors, we demonstrate how to assess recruitment of ß-arrestin-1 and -2 to AT1R and the AT1R/FP dimer in response to Ang II. Surprisingly, ß-arrestin-1 and -2 were recruited to the dimer, in response to PGF2α as well, even though FP alone cannot recruit either ß-arrestin-1 and -2.


Assuntos
Técnicas de Transferência de Energia por Ressonância de Bioluminescência/métodos , Multimerização Proteica , Receptores Acoplados a Proteínas-G/metabolismo , beta-Arrestinas/metabolismo , Angiotensina II/farmacologia , Dinoprosta/farmacologia , Células HEK293 , Humanos , Multimerização Proteica/efeitos dos fármacos , Receptor Tipo 1 de Angiotensina/metabolismo
12.
Cancer Sci ; 110(5): 1735-1745, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-30844117

RESUMO

Homeobox genes are known to be classic examples of the intimate relationship between embryogenesis and tumorigenesis, which are a family of transcriptional factors involved in determining cell identity during early development, and also dysregulated in many malignancies. Previously, HOXB7, HOXC6 and HOXC8 were found abnormally upregulated in esophageal squamous cell carcinoma (ESCC) tissues compared with normal mucosa and seen as poor prognostic predictors for ESCC patients, and were shown to promote cell proliferation and anti-apoptosis in ESCC cells. These three HOX members have a high level of functional redundancy, making it difficult to target a single HOX gene. The aim of the present study was to explore whether ESCC cells are sensitive to HXR9 disrupting the interaction between multiple HOX proteins and their cofactor PBX, which is required for HOX functions. ESCC cell lines (KYSE70, KYSE150, KYSE450) were treated with HXR9 or CXR9, and coimmunoprecipitation and immunofluorescent colocalization were carried out to observe HOX/PBX dimer formation. To further investigate whether HXR9 disrupts the HOX pro-oncogenic function, CCK-8 assay and colony formation assay were carried out. Apoptosis was assessed by flow cytometry, and tumor growth in vivo was investigated in a xenograft model. RNA-seq was used to study the transcriptome of HXR9-treated cells. Results showed that HXR9 blocked HOX/PBX interaction, leading to subsequent transcription alteration of their potential target genes, which are involved in JAK-signal transducer and activator of transcription (STAT) activation and apoptosis inducement. Meanwhile, HXR9 showed an antitumor phenotype, such as inhibiting cell proliferation, inducing cell apoptosis and significantly retarding tumor growth. Therefore, it is suggested that targeting HOX/PBX may be a novel effective treatment for ESCC.


Assuntos
Neoplasias Esofágicas/tratamento farmacológico , Carcinoma de Células Escamosas do Esôfago/tratamento farmacológico , Proteínas de Homeodomínio/metabolismo , Peptídeos/administração & dosagem , Animais , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Neoplasias Esofágicas/genética , Neoplasias Esofágicas/metabolismo , Carcinoma de Células Escamosas do Esôfago/genética , Carcinoma de Células Escamosas do Esôfago/metabolismo , Feminino , Regulação Neoplásica da Expressão Gênica , Humanos , Camundongos , Peptídeos/farmacologia , Multimerização Proteica/efeitos dos fármacos , Análise de Sequência de RNA , Ensaios Antitumorais Modelo de Xenoenxerto
13.
Int J Mol Sci ; 20(6)2019 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-30875875

RESUMO

The mechanism of the antibiotic molecule A22 is yet to be clearly understood. In a previous study, we carried out molecular dynamics simulations of a monomer of the bacterial actin-like MreB in complex with different nucleotides and A22, and suggested that A22 impedes the release of Pi from the active site of MreB after the hydrolysis of ATP, resulting in filament instability. On the basis of the suggestion that Pi release occurs on a similar timescale to polymerization and that polymerization can occur in the absence of nucleotides, we sought in this study to investigate a hypothesis that A22 impedes the conformational change in MreB that is required for polymerization through molecular dynamics simulations of the MreB protofilament in the apo, ATP+, and ATP-A22+ states. We suggest that A22 inhibits MreB in part by antagonizing the ATP-induced structural changes required for polymerization. Our data give further insight into the polymerization/depolymerization dynamics of MreB and the mechanism of A22.


Assuntos
Actinas/química , Actinas/metabolismo , Antibacterianos/farmacologia , Caulobacter crescentus/metabolismo , Actinas/efeitos dos fármacos , Trifosfato de Adenosina/metabolismo , Domínio Catalítico/efeitos dos fármacos , Hidrólise , Modelos Moleculares , Simulação de Dinâmica Molecular , Multimerização Proteica/efeitos dos fármacos , Estrutura Secundária de Proteína/efeitos dos fármacos
14.
Int J Biol Macromol ; 130: 10-18, 2019 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-30794903

RESUMO

The human Receptor for Advanced Glycation End Products (hRAGE) is a pattern recognition receptor implicated in inflammation and adhesion. It is involved in both innate and adaptive immunity. Its aberrant signaling is tied to the pathogenesis of diabetic complications, neurodegenerative disorders, and chronic inflammatory responses. Previous structural studies have focused on its extracellular domains with their canonical constant and variable Ig folds, and to a much lesser extent, the intrinsically disorder cytoplasmic domain. No experimental data are reported on the transmembrane domain, which is integral to signaling. We have constructed, expressed and purified the transmembrane domain attached to the cytoplasmic domain of hRAGE in E. coli. Multiple self-associated forms of these domains were observed in vitro. This pattern of mixed oligomers resembled previously reported in vivo forms of the complete receptor. The self-association of these two domains was further characterized using: SDS-PAGE, intrinsic tryptophan fluorescence and heteronuclear NMR spectroscopy. NMR conditions were assessed across time and temperature within micelles. Our data show that the transmembrane and cytoplasmic domains of hRAGE undergo dynamic oligomerizations that can occur in the absence of its extracellular domains or ligand binding. And, such associations are only partially disrupted even with prolonged incubation in strong detergents.


Assuntos
Membrana Celular/metabolismo , Citoplasma/metabolismo , Micelas , Multimerização Proteica/efeitos dos fármacos , Receptor para Produtos Finais de Glicação Avançada/química , Dodecilsulfato de Sódio/farmacologia , Sequência de Aminoácidos , Linhagem Celular , Humanos , Domínios Proteicos/efeitos dos fármacos , Estrutura Quaternária de Proteína/efeitos dos fármacos , Dodecilsulfato de Sódio/química
15.
Proc Natl Acad Sci U S A ; 116(9): 3863-3872, 2019 02 26.
Artigo em Inglês | MEDLINE | ID: mdl-30733293

RESUMO

Although human epidermal growth factor receptor 2 (HER2)-targeted therapies have dramatically improved the clinical outcome of HER2-positive breast cancer patients, innate and acquired resistance remains an important clinical challenge. New therapeutic approaches and diagnostic tools for identification, stratification, and treatment of patients at higher risk of resistance and recurrence are therefore warranted. Here, we unveil a mechanism controlling the oncogenic activity of HER2: heteromerization with the cannabinoid receptor CB2R. We show that HER2 physically interacts with CB2R in breast cancer cells, and that the expression of these heteromers correlates with poor patient prognosis. The cannabinoid Δ9-tetrahydrocannabinol (THC) disrupts HER2-CB2R complexes by selectively binding to CB2R, which leads to (i) the inactivation of HER2 through disruption of HER2-HER2 homodimers, and (ii) the subsequent degradation of HER2 by the proteasome via the E3 ligase c-CBL. This in turn triggers antitumor responses in vitro and in vivo. Selective targeting of CB2R transmembrane region 5 mimicked THC effects. Together, these findings define HER2-CB2R heteromers as new potential targets for antitumor therapies and biomarkers with prognostic value in HER2-positive breast cancer.


Assuntos
Neoplasias da Mama/líquido cefalorraquidiano , Terapia de Alvo Molecular , Receptor CB2 de Canabinoide/genética , Receptor ErbB-2/genética , Neoplasias da Mama/tratamento farmacológico , Neoplasias da Mama/genética , Neoplasias da Mama/patologia , Linhagem Celular Tumoral , Dronabinol/farmacologia , Resistencia a Medicamentos Antineoplásicos/genética , Feminino , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Humanos , Recidiva Local de Neoplasia/tratamento farmacológico , Recidiva Local de Neoplasia/genética , Recidiva Local de Neoplasia/patologia , Multimerização Proteica/efeitos dos fármacos , Proteínas Proto-Oncogênicas c-cbl/genética , Receptor CB2 de Canabinoide/química , Receptor ErbB-2/química , Transdução de Sinais
16.
Chem Asian J ; 14(7): 952-957, 2019 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-30779325

RESUMO

Here we report fluorescence turn-on synthetic lipid rafts by self-assembly of a cationic distyrylanthracene derivative on a negatively-charged sheet in an aqueous solution. First, the negatively-charged 2D membrane structure is formed by lateral associations of aromatic rods with carboxylate groups. Then, the synthetic rafts are floated on the surface of the negatively-charged sheets through electrostatic interactions. The fluorescence of the synthetic rafts is turned on due to the aggregation of the positively-charged AIE dye on the sheets, facilitating monitoring of the formation of rafts. Concanavalin A (Con A) protein can load hierarchically onto the synthetic rafts at neutral pH to provide discrete Con A aggregates with a uniform size of ≈12 nm. The uniform aggregates of Con A on the synthetic rafts can stimulate Jurkat cells with enhanced efficiency, as compared with random-sized aggregates of Con A.


Assuntos
Antracenos/química , Concanavalina A/química , Substâncias Macromoleculares/química , Microdomínios da Membrana/química , Compostos de Amônio Quaternário/química , Estirenos/química , Fluorescência , Humanos , Células Jurkat , Multimerização Proteica/efeitos dos fármacos , Eletricidade Estática
17.
Transl Res ; 207: 44-55, 2019 05.
Artigo em Inglês | MEDLINE | ID: mdl-30639369

RESUMO

CD151/Tspan24 (SFS-1, PETA3) is one of the best characterized members of the tetraspanin family, whose involvement in breast cancer (BCa) progression was demonstrated both in vitro and in vivo. We have recently reported that in ErbB2-overexpressing BCa cells grown in 3D laminin-rich extracellular matrix, CD151 regulated basal phosphorylation and homodimerization of ErbB2 and sensitized the cells to Herceptin (trastuzumab). Following from these data, we have here analyzed an involvement of CD151 in regulation of ErbB2/ErbB3 heterodimerization and its impact on cell response to Herceptin. CD151 was found to: (1) impair ErbB2/ErbB3 heterodimerization, (2) inhibit heregulin-dependent cell growth in 3D and signaling, and (3) counteract the protective effect of heregulin on Herceptin-mediated growth inhibition. Analysis of tissue samples demonstrated for the first time clinical significance of CD151 in patients with ErbB2-overexpressing BCa undergone trastuzumab-based therapy. Consistent with in vitro results, CD151 impact on disease outcome was ErbB3-dependent. In patients with ErbB3-negative tumors, CD151 significantly improved both overall survival (OS) (hazard ratio [HR] = 0.19, P = 0.034) and progression-free survival (PFS) (HR = 0.36, P = 0.043), while in ErbB3-positive cases it had no significant effect on patient survival (OS: HR = 3.33, P = 0.283; PFS: HR = 2.40, P = 0.208). These results support previous findings and show that CD151 acts as an important component of ErbB2 signaling axis in BCa cells, affecting their sensitivity to ErbB2-targeting therapy.


Assuntos
Neoplasias da Mama/metabolismo , Multimerização Proteica , Receptor ErbB-2/metabolismo , Receptor ErbB-3/metabolismo , Tetraspanina 24/metabolismo , Neoplasias da Mama/patologia , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Intervalo Livre de Doença , Feminino , Humanos , Pessoa de Meia-Idade , Neuregulina-1/farmacologia , Multimerização Proteica/efeitos dos fármacos , Transdução de Sinais/efeitos dos fármacos , Trastuzumab/farmacologia
18.
Chem Asian J ; 14(4): 500-508, 2019 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-30644650

RESUMO

Insoluble aggregates staining positive to amyloid dyes are known histological hallmarks of different neurodegenerative disorders and of type II diabetes. Soluble oligomers are smaller assemblies whose formation prior to or concomitant with amyloid deposition has been associated to the processes of disease propagation and cell death. While the pathogenic mechanisms are complex and differ from disease to disease, both types of aggregates are important biological targets subject to intense investigation in academia and industry. Here we review recent advances in the fundamental understanding of protein aggregation that can be used on the development of anti-amyloid and anti-oligomerization drugs. Specifically, we pinpoint the chemical kinetic aspects that should be attended during the development of high-throughput screening assays and in the hit validation phase. The strategies here devised are expected to establish a connection between basic research and pharmaceutical innovation.


Assuntos
Peptídeos beta-Amiloides/antagonistas & inibidores , Peptídeos beta-Amiloides/metabolismo , Ensaios de Triagem em Larga Escala/métodos , Multimerização Proteica/efeitos dos fármacos , Humanos , Cinética
19.
Nat Commun ; 10(1): 186, 2019 01 14.
Artigo em Inglês | MEDLINE | ID: mdl-30643139

RESUMO

Tetrathiomolybdate (TM) is used in the clinic for the treatment of Wilson's disease by targeting the cellular copper efflux protein ATP7B (WLN). Interestingly, both TM and WLN are associated with the efficacy of cisplatin, a widely used anticancer drug. Herein, we show that TM induces dimerization of the metal-binding domain of ATP7B (WLN4) through a unique sulfur-bridged Mo2S6O2 cluster. TM expels copper ions from Cu-WLN4 and forms a copper-free dimer. The binding of Mo to cysteine residues of WLN4 inhibits platination of the protein. Reaction with multi-domain proteins indicates that TM can also connect two domains in the same molecule, forming Mo-bridged intramolecular crosslinks. These results provide structural and chemical insight into the mechanism of action of TM against ATPase, and reveal the molecular mechanism by which TM attenuates the cisplatin resistance mediated by copper efflux proteins.


Assuntos
Antineoplásicos/farmacologia , Quelantes/farmacologia , Cisplatino/farmacologia , ATPases Transportadoras de Cobre/metabolismo , Molibdênio/farmacologia , Antineoplásicos/uso terapêutico , Quelantes/uso terapêutico , Cisplatino/uso terapêutico , Cobre/metabolismo , ATPases Transportadoras de Cobre/antagonistas & inibidores , ATPases Transportadoras de Cobre/química , Reagentes para Ligações Cruzadas/química , Reagentes para Ligações Cruzadas/farmacologia , Reagentes para Ligações Cruzadas/uso terapêutico , Cristalografia por Raios X , Cisteína/química , Cisteína/metabolismo , Resistencia a Medicamentos Antineoplásicos/efeitos dos fármacos , Sinergismo Farmacológico , Inibidores Enzimáticos/química , Inibidores Enzimáticos/farmacologia , Inibidores Enzimáticos/uso terapêutico , Humanos , Molibdênio/uso terapêutico , Neoplasias/tratamento farmacológico , Neoplasias/patologia , Platina/metabolismo , Domínios e Motivos de Interação entre Proteínas/efeitos dos fármacos , Multimerização Proteica/efeitos dos fármacos , Estrutura Secundária de Proteína
20.
Mol Biol Cell ; 30(4): 478-490, 2019 02 15.
Artigo em Inglês | MEDLINE | ID: mdl-30566031

RESUMO

In mammalian cells, the Golgi reassembly stacking protein of 65 kDa (GRASP65) has been implicated in both Golgi stacking and ribbon linking by forming trans-oligomers. To better understand its function and regulation, we used biochemical methods to identify the DnaJ homolog subfamily A member 1 (DjA1) as a novel GRASP65-binding protein. In cells, depletion of DjA1 resulted in Golgi fragmentation, short and improperly aligned cisternae, and delayed Golgi reassembly after nocodazole washout. In vitro, immunodepletion of DjA1 from interphase cytosol reduced its activity to enhance GRASP65 oligomerization and Golgi membrane fusion, while adding purified DjA1 enhanced GRASP65 oligomerization. DjA1 is a cochaperone of Heat shock cognate 71-kDa protein (Hsc70), but the activity of DjA1 in Golgi structure formation is independent of its cochaperone activity or Hsc70, rather, through DjA1-GRASP65 interaction to promote GRASP65 oligomerization. Thus, DjA1 interacts with GRASP65 to enhance Golgi structure formation through the promotion of GRASP65 trans-oligomerization.


Assuntos
Complexo de Golgi/metabolismo , Proteínas da Matriz do Complexo de Golgi/metabolismo , Proteínas de Choque Térmico HSP40/metabolismo , Complexo de Golgi/ultraestrutura , Células HeLa , Humanos , Fusão de Membrana/efeitos dos fármacos , Nocodazol/farmacologia , Ligação Proteica/efeitos dos fármacos , Mapeamento de Interação de Proteínas , Multimerização Proteica/efeitos dos fármacos , Transporte Proteico/efeitos dos fármacos
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