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1.
J Med Chem ; 2020 Mar 19.
Artigo em Inglês | MEDLINE | ID: mdl-32130004

RESUMO

Many patients with multiple myeloma (MM) initially respond to treatment with modern combination regimens including immunomodulatory agents (lenalidomide and pomalidomide) and proteasome inhibitors. However, some patients lack an initial response to therapy (i.e., are refractory), and although the mean survival of MM patients has more than doubled in recent years, most patients will eventually relapse. To address this need, we explored the potential of novel cereblon E3 ligase modulators (CELMoDs) for the treatment of patients with relapsed or refractory multiple myeloma (RRMM). We found that optimization beyond potency of degradation, including degradation efficiency and kinetics, could provide efficacy in a lenalidomide-resistant setting. Guided by both phenotypic and protein degradation data, we describe a series of CELMoDs for the treatment of RRMM, culminating in the discovery of CC-92480, a novel protein degrader and the first CELMoD to enter clinical development that was specifically designed for efficient and rapid protein degradation kinetics.

2.
J Med Chem ; 63(3): 1068-1083, 2020 Feb 13.
Artigo em Inglês | MEDLINE | ID: mdl-31955578

RESUMO

Recent clinical evaluation of everolimus for seizure reduction in patients with tuberous sclerosis complex (TSC), a disease with overactivated mechanistic target of rapamycin (mTOR) signaling, has demonstrated the therapeutic value of mTOR inhibitors for central nervous system (CNS) indications. Given that everolimus is an incomplete inhibitor of the mTOR function, we sought to develop a new mTOR inhibitor that has improved properties and is suitable for CNS disorders. Starting from an in-house purine-based compound, optimization of the physicochemical properties of a thiazolopyrimidine series led to the discovery of the small molecule 7, a potent and selective brain-penetrant ATP-competitive mTOR inhibitor. In neuronal cell-based models of mTOR hyperactivity, 7 corrected the mTOR pathway activity and the resulting neuronal overgrowth phenotype. The new mTOR inhibitor 7 showed good brain exposure and significantly improved the survival rate of mice with neuronal-specific ablation of the Tsc1 gene. These results demonstrate the potential utility of this tool compound to test therapeutic hypotheses that depend on mTOR hyperactivity in the CNS.

3.
Nat Chem Biol ; 15(10): 937-944, 2019 10.
Artigo em Inglês | MEDLINE | ID: mdl-31527835

RESUMO

Targeted protein degradation as a therapeutic modality has seen dramatic progress and massive investment in recent years because of the convergence of two key scientific breakthroughs: optimization of first-generation peptidic proteolysis-targeted chimeras (PROTACs) into more drug-like molecules able to support in vivo proof of concept and the discovery that clinical molecules function as degraders by binding and repurposing the proteins cereblon and DCAF15. This provided clinical validation for the general approach through the cereblon modulator class of drugs and provided highly drug-like and ligand-efficient E3 ligase binders upon which to tether target-binding moieties. Increasingly rational and systematic approaches including biophysical and structural studies on ternary complexes are being leveraged as the field advances. In this Perspective we summarize the discoveries that have laid the foundation for future degradation therapeutics, focusing on those classes of small molecules that redirect E3 ubiquitin ligases to non-native substrates.


Assuntos
Proteólise/efeitos dos fármacos , Sítios de Ligação , Humanos , Complexo de Endopeptidases do Proteassoma , Ligação Proteica , Bibliotecas de Moléculas Pequenas/química , Ubiquitina-Proteína Ligases/química , Ubiquitina-Proteína Ligases/metabolismo
4.
J Med Chem ; 61(24): 11021-11036, 2018 12 27.
Artigo em Inglês | MEDLINE | ID: mdl-30407821

RESUMO

Spinal muscular atrophy (SMA), a rare neuromuscular disorder, is the leading genetic cause of death in infants and toddlers. SMA is caused by the deletion or a loss of function mutation of the survival motor neuron 1 (SMN1) gene. In humans, a second closely related gene SMN2 exists; however it codes for a less stable SMN protein. In recent years, significant progress has been made toward disease modifying treatments for SMA by modulating SMN2 pre-mRNA splicing. Herein, we describe the discovery of LMI070/branaplam, a small molecule that stabilizes the interaction between the spliceosome and SMN2 pre-mRNA. Branaplam (1) originated from a high-throughput phenotypic screening hit, pyridazine 2, and evolved via multiparameter lead optimization. In a severe mouse SMA model, branaplam treatment increased full-length SMN RNA and protein levels, and extended survival. Currently, branaplam is in clinical studies for SMA.


Assuntos
Encéfalo/efeitos dos fármacos , Canal de Potássio ERG1/metabolismo , Atrofia Muscular Espinal/tratamento farmacológico , Piridazinas/química , Administração Oral , Animais , Encéfalo/metabolismo , Linhagem Celular , Cristalografia por Raios X , Relação Dose-Resposta a Droga , Avaliação Pré-Clínica de Medicamentos/métodos , Canal de Potássio ERG1/antagonistas & inibidores , Humanos , Camundongos Endogâmicos C57BL , Neurônios Motores/efeitos dos fármacos , Atrofia Muscular Espinal/genética , Piridazinas/farmacologia , Relação Quantitativa Estrutura-Atividade , Processamento de RNA , Ratos Sprague-Dawley , Proteína 1 de Sobrevivência do Neurônio Motor/genética , Proteína 1 de Sobrevivência do Neurônio Motor/metabolismo , Proteína 2 de Sobrevivência do Neurônio Motor/genética
5.
Nat Chem Biol ; 14(10): 981-987, 2018 10.
Artigo em Inglês | MEDLINE | ID: mdl-30190590

RESUMO

Targeted protein degradation via small-molecule modulation of cereblon offers vast potential for the development of new therapeutics. Cereblon-binding therapeutics carry the safety risks of thalidomide, which caused an epidemic of severe birth defects characterized by forelimb shortening or phocomelia. Here we show that thalidomide is not teratogenic in transgenic mice expressing human cereblon, indicating that binding to cereblon is not sufficient to cause birth defects. Instead, we identify SALL4 as a thalidomide-dependent cereblon neosubstrate. Human mutations in SALL4 cause Duane-radial ray, IVIC, and acro-renal-ocular syndromes with overlapping clinical presentations to thalidomide embryopathy, including phocomelia. SALL4 is degraded in rabbits but not in resistant organisms such as mice because of SALL4 sequence variations. This work expands the scope of cereblon neosubstrate activity within the formerly 'undruggable' C2H2 zinc finger family and offers a path toward safer therapeutics through an improved understanding of the molecular basis of thalidomide-induced teratogenicity.


Assuntos
Regulação da Expressão Gênica , Peptídeo Hidrolases/química , Teratogênios/química , Talidomida/química , Fatores de Transcrição/química , Animais , Proteínas de Ligação a DNA/química , Proteínas de Ligação a DNA/genética , Homozigoto , Humanos , Imuno-Histoquímica , Células-Tronco Pluripotentes Induzidas , Ligantes , Masculino , Camundongos , Camundongos Transgênicos , Mutação , Proteínas do Tecido Nervoso/química , Proteínas do Tecido Nervoso/genética , Peptídeo Hidrolases/genética , Proteólise , Coelhos , Testículo/metabolismo , Fatores de Transcrição/genética , Ubiquitina-Proteína Ligases/metabolismo , Dedos de Zinco
6.
J Pharmacol Exp Ther ; 367(1): 147-154, 2018 10.
Artigo em Inglês | MEDLINE | ID: mdl-30076263

RESUMO

Myeloperoxidase (MPO) is a leukocyte-derived redox enzyme that has been linked to oxidative stress and damage in many inflammatory states, including cardiovascular disease. We have discovered aminopyridines that are potent mechanism-based inhibitors of MPO, with significant selectivity over the closely related thyroid peroxidase. 1-((6-Aminopyridin-3-yl)methyl)-3-(4-bromophenyl)urea (Aminopyridine 2) inhibited MPO in human plasma and blocked MPO-dependent vasomotor dysfunction ex vivo in rat aortic rings. Aminopyridine 2 also showed high oral bioavailability and inhibited MPO activity in vivo in a mouse model of peritonitis. Aminopyridine 2 could effectively be administered as a food admixture, making it an important tool for assessing the relative importance of MPO in preclinical models of chronic inflammatory disease.


Assuntos
Aminopiridinas/farmacologia , Inibidores Enzimáticos/farmacologia , Peroxidase/antagonistas & inibidores , Animais , Aorta/efeitos dos fármacos , Aorta/metabolismo , Disponibilidade Biológica , Humanos , Inflamação/tratamento farmacológico , Inflamação/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Ratos , Ratos Sprague-Dawley
7.
J Med Chem ; 61(7): 2837-2864, 2018 04 12.
Artigo em Inglês | MEDLINE | ID: mdl-29562737

RESUMO

In breast cancer, estrogen receptor alpha (ERα) positive cancer accounts for approximately 74% of all diagnoses, and in these settings, it is a primary driver of cell proliferation. Treatment of ERα positive breast cancer has long relied on endocrine therapies such as selective estrogen receptor modulators, aromatase inhibitors, and selective estrogen receptor degraders (SERDs). The steroid-based anti-estrogen fulvestrant (5), the only approved SERD, is effective in patients who have not previously been treated with endocrine therapy as well as in patients who have progressed after receiving other endocrine therapies. Its efficacy, however, may be limited due to its poor physicochemical properties. We describe the design and synthesis of a series of potent benzothiophene-containing compounds that exhibit oral bioavailability and preclinical activity as SERDs. This article culminates in the identification of LSZ102 (10), a compound in clinical development for the treatment of ERα positive breast cancer.


Assuntos
Antineoplásicos/síntese química , Antineoplásicos/farmacologia , Neoplasias da Mama/tratamento farmacológico , Neoplasias da Mama/metabolismo , Receptor alfa de Estrogênio/efeitos dos fármacos , Moduladores Seletivos de Receptor Estrogênico/síntese química , Moduladores Seletivos de Receptor Estrogênico/farmacologia , Animais , Antineoplásicos/farmacocinética , Disponibilidade Biológica , Desenho de Drogas , Descoberta de Drogas , Feminino , Humanos , Células MCF-7 , Camundongos , Camundongos Nus , Ratos , Ratos Sprague-Dawley , Ratos Wistar , Moduladores Seletivos de Receptor Estrogênico/farmacocinética , Tiofenos/síntese química , Tiofenos/farmacologia , Ensaios Antitumorais Modelo de Xenoenxerto
8.
J Med Chem ; 60(12): 5002-5014, 2017 06 22.
Artigo em Inglês | MEDLINE | ID: mdl-28549219

RESUMO

Over the past several decades, the frequency of antibacterial resistance in hospitals, including multidrug resistance (MDR) and its association with serious infectious diseases, has increased at alarming rates. Pseudomonas aeruginosa is a leading cause of nosocomial infections, and resistance to virtually all approved antibacterial agents is emerging in this pathogen. To address the need for new agents to treat MDR P. aeruginosa, we focused on inhibiting the first committed step in the biosynthesis of lipid A, the deacetylation of uridyldiphospho-3-O-(R-hydroxydecanoyl)-N-acetylglucosamine by the enzyme LpxC. We approached this through the design, synthesis, and biological evaluation of novel hydroxamic acid LpxC inhibitors, exemplified by 1, where cytotoxicity against mammalian cell lines was reduced, solubility and plasma-protein binding were improved while retaining potent anti-pseudomonal activity in vitro and in vivo.


Assuntos
Amidoidrolases/antagonistas & inibidores , Antibacterianos/química , Antibacterianos/farmacologia , Inibidores Enzimáticos/química , Inibidores Enzimáticos/farmacologia , Amidoidrolases/química , Animais , Antibacterianos/síntese química , Técnicas de Química Sintética , Cristalografia por Raios X , Desenho de Drogas , Avaliação Pré-Clínica de Medicamentos/métodos , Farmacorresistência Bacteriana Múltipla/efeitos dos fármacos , Inibidores Enzimáticos/síntese química , Feminino , Células Hep G2/efeitos dos fármacos , Humanos , Células K562/efeitos dos fármacos , Camundongos Endogâmicos BALB C , Testes de Sensibilidade Microbiana , Simulação de Acoplamento Molecular , Infecções por Pseudomonas/tratamento farmacológico , Pseudomonas aeruginosa/efeitos dos fármacos , Pseudomonas aeruginosa/enzimologia , Relação Estrutura-Atividade
9.
J Med Chem ; 60(7): 2790-2818, 2017 04 13.
Artigo em Inglês | MEDLINE | ID: mdl-28296398

RESUMO

Tetrahydroisoquinoline 40 has been identified as a potent ERα antagonist and selective estrogen receptor degrader (SERD), exhibiting good oral bioavailability, antitumor efficacy, and SERD activity in vivo. We outline the discovery and chemical optimization of the THIQ scaffold leading to THIQ 40 and showcase the racemization of the scaffold, pharmacokinetic studies in preclinical species, and the in vivo efficacy of THIQ 40 in a MCF-7 human breast cancer xenograft model.


Assuntos
Antineoplásicos/química , Antineoplásicos/uso terapêutico , Neoplasias da Mama/tratamento farmacológico , Mama/efeitos dos fármacos , Receptor alfa de Estrogênio/antagonistas & inibidores , Tetra-Hidroisoquinolinas/química , Tetra-Hidroisoquinolinas/uso terapêutico , Acrilatos/química , Acrilatos/farmacocinética , Acrilatos/farmacologia , Acrilatos/uso terapêutico , Administração Oral , Animais , Antineoplásicos/farmacocinética , Antineoplásicos/farmacologia , Mama/metabolismo , Mama/patologia , Neoplasias da Mama/metabolismo , Neoplasias da Mama/patologia , Cães , Descoberta de Drogas , Receptor alfa de Estrogênio/metabolismo , Feminino , Humanos , Células MCF-7 , Camundongos Endogâmicos C57BL , Simulação de Acoplamento Molecular , Proteólise/efeitos dos fármacos , Tetra-Hidroisoquinolinas/farmacocinética , Tetra-Hidroisoquinolinas/farmacologia
10.
Angew Chem Int Ed Engl ; 55(46): 14218-14238, 2016 11 07.
Artigo em Inglês | MEDLINE | ID: mdl-27723189

RESUMO

Can classical and modern chemical C-H oxidation reactions complement biotransformation in the synthesis of drug metabolites? We have surveyed the literature in an effort to try to answer this important question of major practical significance in the pharmaceutical industry. Drug metabolites are required throughout all phases of the drug discovery and development process; however, their synthesis is still an unsolved problem. This Review, not intended to be comprehensive or historical, highlights relevant applications of chemical C-H oxidation reactions, electrochemistry and microfluidic technologies to drug templates in order to access drug metabolites, and also highlights promising reactions to this end. Where possible or appropriate, the contrast with biotransformation is drawn. In doing so, we have tried to identify gaps where they exist in the hope to spur further activity in this very important research area.


Assuntos
Preparações Farmacêuticas/química , Elementos de Transição/química , Produtos Biológicos/química , Produtos Biológicos/metabolismo , Carbono/química , Catálise , Técnicas Eletroquímicas , Hidrogênio/química , Técnicas Analíticas Microfluídicas , Oxirredução , Preparações Farmacêuticas/metabolismo
11.
Drug Metab Dispos ; 44(6): 809-20, 2016 06.
Artigo em Inglês | MEDLINE | ID: mdl-27029743

RESUMO

Daclatasvir is a first-in-class, potent, and selective inhibitor of the hepatitis C virus nonstructural protein 5A replication complex. In support of nonclinical studies during discovery and exploratory development, liquid chromatography-tandem mass spectrometry and nuclear magnetic resonance were used in connection with synthetic and radiosynthetic approaches to investigate the biotransformation of daclatasvir in vitro and in cynomolgus monkeys, dogs, mice, and rats. The results of these studies indicated that disposition of daclatasvir was accomplished mainly by the release of unchanged daclatasvir into bile and feces and, secondarily, by oxidative metabolism. Cytochrome P450s were the main enzymes involved in the metabolism of daclatasvir. Oxidative pathways included δ-oxidation of the pyrrolidine moiety, resulting in ring opening to an aminoaldehyde intermediate followed by an intramolecular reaction between the aldehyde and the proximal imidazole nitrogen atom. Despite robust formation of the resulting metabolite in multiple systems, rates of covalent binding to protein associated with metabolism of daclatasvir were modest (55.2-67.8 pmol/mg/h) in nicotinamide adenine dinucleotide phosphate (reduced form)-supplemented liver microsomes (human, monkey, rat), suggesting that intramolecular rearrangement was favored over intermolecular binding in the formation of this metabolite. This biotransformation profile supported the continued development of daclatasvir, which is now marketed for the treatment of chronic hepatitis C virus infection.


Assuntos
Biotransformação/fisiologia , Imidazóis/metabolismo , Pirrolidinas/metabolismo , Animais , Bile/metabolismo , Cromatografia Líquida de Alta Pressão/métodos , Sistema Enzimático do Citocromo P-450/metabolismo , Cães , Haplorrinos , Hepatócitos/metabolismo , Humanos , Macaca fascicularis , Espectroscopia de Ressonância Magnética/métodos , Masculino , Espectrometria de Massas/métodos , Camundongos , Camundongos Endogâmicos BALB C , Microssomos Hepáticos/metabolismo , Oxirredução , Ratos , Ratos Sprague-Dawley
13.
ACS Med Chem Lett ; 7(1): 72-6, 2016 Jan 14.
Artigo em Inglês | MEDLINE | ID: mdl-26819669

RESUMO

Autophagy is a dynamic process that regulates lysosomal-dependent degradation of cellular components. Until recently the study of autophagy has been hampered by the lack of reliable pharmacological tools, but selective inhibitors are now available to modulate the PI 3-kinase VPS34, which is required for autophagy. Here we describe the discovery of potent and selective VPS34 inhibitors, their pharmacokinetic (PK) properties, and ability to inhibit autophagy in cellular and mouse models.

14.
Bioorg Med Chem Lett ; 26(1): 160-7, 2016 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-26584882

RESUMO

6,6-Fused ring systems including tetrahydroisoquinolines and tetrahydropyrido[3,4-d]pyrimidines have been explored as possible replacements for the piperazine benzamide portion of the HIV-1 attachment inhibitor BMS-663068. In initial studies, the tetrahydroisoquinoline compounds demonstrate sub-nanomolar activity in a HIV-1 pseudotype viral infection assay used as the initial screen for inhibitory activity. Analysis of SARs and approaches to optimization for an improved drug-like profile are examined herein.


Assuntos
Compostos Aza/química , Benzamidas/química , Descoberta de Drogas , Inibidores da Fusão de HIV/química , Inibidores da Fusão de HIV/farmacologia , HIV-1/efeitos dos fármacos , Indóis/química , Piperazinas/química , Tetra-Hidroisoquinolinas/farmacologia , Ligação Viral/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Relação Dose-Resposta a Droga , Proteína gp120 do Envelope de HIV/antagonistas & inibidores , Proteína gp120 do Envelope de HIV/genética , Inibidores da Fusão de HIV/síntese química , Infecções por HIV/tratamento farmacológico , Infecções por HIV/genética , Células HeLa , Humanos , Estrutura Molecular , Relação Estrutura-Atividade , Tetra-Hidroisoquinolinas/síntese química , Tetra-Hidroisoquinolinas/química , Replicação Viral/efeitos dos fármacos
16.
Nat Chem Biol ; 11(7): 511-7, 2015 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-26030728

RESUMO

Spinal muscular atrophy (SMA), which results from the loss of expression of the survival of motor neuron-1 (SMN1) gene, represents the most common genetic cause of pediatric mortality. A duplicate copy (SMN2) is inefficiently spliced, producing a truncated and unstable protein. We describe herein a potent, orally active, small-molecule enhancer of SMN2 splicing that elevates full-length SMN protein and extends survival in a severe SMA mouse model. We demonstrate that the molecular mechanism of action is via stabilization of the transient double-strand RNA structure formed by the SMN2 pre-mRNA and U1 small nuclear ribonucleic protein (snRNP) complex. The binding affinity of U1 snRNP to the 5' splice site is increased in a sequence-selective manner, discrete from constitutive recognition. This new mechanism demonstrates the feasibility of small molecule-mediated, sequence-selective splice modulation and the potential for leveraging this strategy in other splicing diseases.


Assuntos
Processamento Alternativo , Atrofia Muscular Espinal/tratamento farmacológico , RNA de Cadeia Dupla/agonistas , Ribonucleoproteína Nuclear Pequena U1/agonistas , Bibliotecas de Moléculas Pequenas/farmacologia , Proteína 2 de Sobrevivência do Neurônio Motor/metabolismo , Animais , Sítios de Ligação , Modelos Animais de Doenças , Feminino , Expressão Gênica , Humanos , Camundongos , Camundongos Transgênicos , Modelos Moleculares , Atrofia Muscular Espinal/metabolismo , Atrofia Muscular Espinal/mortalidade , Atrofia Muscular Espinal/patologia , Ligação Proteica/efeitos dos fármacos , Estabilidade Proteica/efeitos dos fármacos , Proteólise , Precursores de RNA/agonistas , Precursores de RNA/química , Precursores de RNA/metabolismo , RNA de Cadeia Dupla/química , RNA de Cadeia Dupla/metabolismo , Ribonucleoproteína Nuclear Pequena U1/química , Ribonucleoproteína Nuclear Pequena U1/metabolismo , Bibliotecas de Moléculas Pequenas/síntese química , Bibliotecas de Moléculas Pequenas/metabolismo , Análise de Sobrevida , Proteína 2 de Sobrevivência do Neurônio Motor/química , Proteína 2 de Sobrevivência do Neurônio Motor/genética
17.
Nat Commun ; 6: 5943, 2015 Jan 12.
Artigo em Inglês | MEDLINE | ID: mdl-25581471

RESUMO

Alkaloids constitute a large family of natural products possessing diverse biological properties. Their unique and complex structures have inspired numerous innovations in synthetic chemistry. In the realm of late-stage C-H functionalization, alkaloids remain a significant challenge due to the presence of the basic amine and a variety of other functional groups. Herein we report the first examples of dirhodium(II)-catalysed intermolecular C-H insertion into complex natural products containing nucleophilic tertiary amines to generate a C-C bond. The application to a diverse range of alkaloids and drug molecules demonstrates remarkable chemoselectivity and predictable regioselectivity. The capacity for late-stage diversification is highlighted in the catalyst-controlled selective functionalizations of the alkaloid brucine. The remarkable selectivity observed, particularly for site-specific C-H insertion at N-methyl functionalities, offers utility in a range of applications where efficient installation of synthetic handles on complex alkaloids is desired.


Assuntos
Alcaloides/química , Carbono/química , Hidrogênio/química , Ródio/química , Aminas/química , Produtos Biológicos/química , Catálise , Química Farmacêutica/métodos , Desenho de Drogas , Espectroscopia de Ressonância Magnética , Estricnina/análogos & derivados , Estricnina/química
18.
Bioorg Med Chem Lett ; 24(21): 5045-9, 2014 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-25266782

RESUMO

A previous disclosure from this lab highlighted the discovery of pyridyl amides as potent 11ß-HSD1 inhibitors. In order to build additional novelty and polarity into this chemotype, replacement of the hydrogen-bonding carbonyl (CO) pharmacophore with the bioisosteric sulfonyl (SO2) group was examined. Despite initial comparisons suggesting the corresponding sulfonamides exhibited weaker activity versus their carbonyl counterparts, further optimization was performed in an effort to identify various potent and unique leads for the program. Judicious incorporation of polar moieties resulted in the identification of compounds with enhanced potency and lipophilicity profiles, resulting in leads with superior aqueous solubility and liver microsomal stability.


Assuntos
11-beta-Hidroxiesteroide Desidrogenase Tipo 1/antagonistas & inibidores , Inibidores Enzimáticos/química , Doenças Metabólicas/tratamento farmacológico , Sulfonamidas/química , 11-beta-Hidroxiesteroide Desidrogenase Tipo 1/metabolismo , 11-beta-Hidroxiesteroide Desidrogenase Tipo 2/antagonistas & inibidores , 11-beta-Hidroxiesteroide Desidrogenase Tipo 2/metabolismo , Sítios de Ligação , Avaliação Pré-Clínica de Medicamentos , Inibidores Enzimáticos/metabolismo , Inibidores Enzimáticos/uso terapêutico , Humanos , Microssomos Hepáticos/metabolismo , Simulação de Acoplamento Molecular , Ligação Proteica , Estrutura Terciária de Proteína , Relação Estrutura-Atividade , Sulfonamidas/metabolismo , Sulfonamidas/uso terapêutico
19.
Nat Cell Biol ; 16(11): 1069-79, 2014 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-25327288

RESUMO

Cells rely on autophagy to clear misfolded proteins and damaged organelles to maintain cellular homeostasis. In this study we use the new autophagy inhibitor PIK-III to screen for autophagy substrates. PIK-III is a selective inhibitor of VPS34 that binds a unique hydrophobic pocket not present in related kinases such as PI(3)Kα. PIK-III acutely inhibits autophagy and de novo lipidation of LC3, and leads to the stabilization of autophagy substrates. By performing ubiquitin-affinity proteomics on PIK-III-treated cells we identified substrates including NCOA4, which accumulates in ATG7-deficient cells and co-localizes with autolysosomes. NCOA4 directly binds ferritin heavy chain-1 (FTH1) to target the iron-binding ferritin complex with a relative molecular mass of 450,000 to autolysosomes following starvation or iron depletion. Interestingly, Ncoa4(-/-) mice exhibit a profound accumulation of iron in splenic macrophages, which are critical for the reutilization of iron from engulfed red blood cells. Taken together, the results of this study provide a new mechanism for selective autophagy of ferritin and reveal a previously unappreciated role for autophagy and NCOA4 in the control of iron homeostasis in vivo.


Assuntos
Autofagia/fisiologia , Classe III de Fosfatidilinositol 3-Quinases/antagonistas & inibidores , Ferritinas/metabolismo , Homeostase/fisiologia , Ferro/metabolismo , Coativadores de Receptor Nuclear/metabolismo , Animais , Autofagia/efeitos dos fármacos , Células Cultivadas , Humanos , Lisossomos/metabolismo , Camundongos , Fagossomos/metabolismo , Ligação Proteica
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