RESUMO
Chemical modulation of proteins enables a mechanistic understanding of biology and represents the foundation of most therapeutics. However, despite decades of research, 80% of the human proteome lacks functional ligands. Chemical proteomics has advanced fragment-based ligand discovery toward cellular systems, but throughput limitations have stymied the scalable identification of fragment-protein interactions. We report proteome-wide maps of protein-binding propensity for 407 structurally diverse small-molecule fragments. We verified that identified interactions can be advanced to active chemical probes of E3 ubiquitin ligases, transporters, and kinases. Integrating machine learning binary classifiers further enabled interpretable predictions of fragment behavior in cells. The resulting resource of fragment-protein interactions and predictive models will help to elucidate principles of molecular recognition and expedite ligand discovery efforts for hitherto undrugged proteins.
Assuntos
Descoberta de Drogas , Aprendizado de Máquina , Proteômica , Bibliotecas de Moléculas Pequenas , Humanos , Ligantes , Ligação Proteica , Proteoma/metabolismo , Proteômica/métodos , Bibliotecas de Moléculas Pequenas/química , Ubiquitina-Proteína Ligases/metabolismoRESUMO
Recombinant human leptin (metreleptin) reduces hepatic lipid content in patients with lipodystrophy and overweight patients with non-alcoholic fatty liver disease and relative hypoleptinemia independent of its anorexic action. In rodents, leptin signaling in the brain increases very-low-density lipoprotein triglyceride (VLDL-TG) secretion and reduces hepatic lipid content via the vagus nerve. In this randomized, placebo-controlled crossover trial (EudraCT Nr. 2017-003014-22), we tested whether a comparable mechanism regulates hepatic lipid metabolism in humans. A single metreleptin injection stimulated hepatic VLDL-TG secretion (primary outcome) and reduced hepatic lipid content in fasted, lean men (n = 13, age range 20-38 years) but failed to do so in metabolically healthy liver transplant recipients (n = 9, age range 26-62 years) who represent a model for hepatic denervation. In an independent cohort of lean men (n = 10, age range 23-31 years), vagal stimulation by modified sham feeding replicated the effects of metreleptin on VLDL-TG secretion. Therefore, we propose that leptin has anti-steatotic properties that are independent of food intake by stimulating hepatic VLDL-TG export via a brain-vagus-liver axis.
Assuntos
Leptina , Hepatopatia Gordurosa não Alcoólica , Masculino , Humanos , Adulto Jovem , Adulto , Leptina/farmacologia , Leptina/metabolismo , Lipoproteínas VLDL/metabolismo , Triglicerídeos/metabolismo , Fígado/metabolismo , Hepatopatia Gordurosa não Alcoólica/metabolismo , Nervo Vago/metabolismoRESUMO
[Figure: see text].
Assuntos
Coagulação Sanguínea/efeitos dos fármacos , Produtos de Degradação da Fibrina e do Fibrinogênio/farmacologia , Leucócitos/efeitos dos fármacos , Fragmentos de Peptídeos/farmacologia , Migração Transendotelial e Transepitelial/efeitos dos fármacos , Veia Cava Inferior/metabolismo , Trombose Venosa/sangue , Animais , Antígenos CD/metabolismo , Caderinas/metabolismo , Estudos de Casos e Controles , Técnicas de Cocultura , Modelos Animais de Doenças , Feminino , Humanos , Leucócitos/metabolismo , Macrófagos/efeitos dos fármacos , Macrófagos/metabolismo , Camundongos Endogâmicos BALB C , Fragmentos de Peptídeos/sangue , Embolia Pulmonar/sangue , Células THP-1 , Fatores de Tempo , Veia Cava Inferior/patologia , Trombose Venosa/patologiaRESUMO
Cancer-associated, loss-of-function mutations in genes encoding subunits of the BRG1/BRM-associated factor (BAF) chromatin-remodeling complexes1-8 often cause drastic chromatin accessibility changes, especially in important regulatory regions9-19. However, it remains unknown how these changes are established over time (for example, immediate consequences or long-term adaptations), and whether they are causative for intracomplex synthetic lethalities, abrogating the formation or activity of BAF complexes9,20-24. In the present study, we use the dTAG system to induce acute degradation of BAF subunits and show that chromatin alterations are established faster than the duration of one cell cycle. Using a pharmacological inhibitor and a chemical degrader of the BAF complex ATPase subunits25,26, we show that maintaining genome accessibility requires constant ATP-dependent remodeling. Completely abolishing BAF complex function by acute degradation of a synthetic lethal subunit in a paralog-deficient background results in an almost complete loss of chromatin accessibility at BAF-controlled sites, especially also at superenhancers, providing a mechanism for intracomplex synthetic lethalities.