RESUMO
DYRK1A phosphorylates proteins involved in neurological disorders in an intermolecular manner. Meanwhile, during the protein folding process of DYRK1A, a transitional folding intermediate catalyzes the intramolecular autophosphorylation required for the "one-off" inceptive activation and stabilization. In our previous study, a small molecule termed FINDY (1) was identified, which inhibits the folding intermediate-catalyzed intramolecular autophosphorylation of DYRK1A but not the folded state-catalyzed intermolecular phosphorylation. However, the structural features of FINDY (1) responsible for this intermediate-selective inhibition remain elusive. In this study, structural derivatives of FINDY (1) were designed and synthesized according to its predicted binding mode in the ATP pocket of DYRK1A. Quantitative structure-activity relationship (QSAR) of the derivatives revealed that the selectivity against the folding intermediate is determined by steric hindrance between the bulky hydrophobic moiety of the derivatives and the entrance to the pocket. In addition, a potent derivative 3 was identified, which inhibited the folding intermediate more strongly than FINDY (1); it was designated as dp-FINDY. Although dp-FINDY (3) did not inhibit the folded state, as well as FINDY (1), it inhibited the intramolecular autophosphorylation of DYRK1A in an in vitro cell-free protein synthesis assay. Furthermore, dp-FINDY (3) destabilized endogenous DYRK1A in HEK293 cells. This study provides structural insights into the folding intermediate-selective inhibition of DYRK1A and expands the chemical options for the design of a kinase inhibitor.
Assuntos
Inibidores de Proteínas Quinases/farmacologia , Proteínas Serina-Treonina Quinases/antagonistas & inibidores , Proteínas Tirosina Quinases/antagonistas & inibidores , Tiazóis/farmacologia , Sobrevivência Celular/efeitos dos fármacos , Células Cultivadas , Relação Dose-Resposta a Droga , Células HEK293 , Humanos , Estrutura Molecular , Inibidores de Proteínas Quinases/química , Proteínas Serina-Treonina Quinases/metabolismo , Proteínas Tirosina Quinases/metabolismo , Relação Estrutura-Atividade , Tiazóis/química , Quinases DyrkRESUMO
An efficient transformation of dibenzoxaborins to dibenzofurans by deborylative ring contraction was achieved under mild conditions using a copper catalyst. The method showed a broad substrate scope enabling the preparation of various dibenzofurans, including those bearing a functional group. The ready availability of various dibenzoxaborins enhances the utility of this method, as demonstrated by the regiodivergent synthesis of dibenzofurans.
RESUMO
In this study, three reaction mechanisms of a benzyne-nickel (Ni) complex ([Ni(C6H4)(dcpe)]) with iodomethane during the methylation process were investigated, namely (a) SN2 reaction of the benzyne-Ni complex with iodomethane, (b) concerted σ-bond metathesis during the bond breaking/forming processes, and (c) oxidative addition of iodomethane to the Ni-center and the subsequent reductive elimination process. DFT calculations revealed that the reaction barrier of the SN2 reaction is slightly lower than those of the other mechanisms. The results of orbital analyses suggest that [Ni(C6H4)(dcpe)] forms a metallacycle structure between benzyne and the NiII (3d8) center instead of the η2-structure with the Ni0 (3d10) center. The metallacycle structures became inappropriate as the intermediates of oxidative addition in the formation of the NiII-Me bond, avoiding further oxidation to the high-valent NiIV. The high free energy along σ-bond metathesis was generated from the steric hindrance, thus invoking methylation and Ni-I bond formation concertedly.
RESUMO
Down syndrome (DS) caused by trisomy of chromosome 21 is the most common genetic cause of intellectual disability. Although the prenatal diagnosis of DS has become feasible, there are no therapies available for the rescue of DS-related neurocognitive impairment. A growth inducer newly identified in our screen of neural stem cells (NSCs) has potent inhibitory activity against dual-specificity tyrosine phosphorylation-regulated kinase 1A (DYRK1A) and was found to rescue proliferative deficits in Ts65Dn-derived neurospheres and human NSCs derived from individuals with DS. The oral administration of this compound, named ALGERNON (altered generation of neurons), restored NSC proliferation in murine models of DS and increased the number of newborn neurons. Moreover, administration of ALGERNON to pregnant dams rescued aberrant cortical formation in DS mouse embryos and prevented the development of abnormal behaviors in DS offspring. These data suggest that the neurogenic phenotype of DS can be prevented by ALGERNON prenatal therapy.
Assuntos
Síndrome de Down/tratamento farmacológico , Terapias Fetais , Células-Tronco Neurais/efeitos dos fármacos , Neurogênese/efeitos dos fármacos , Proteínas Serina-Treonina Quinases/antagonistas & inibidores , Proteínas Tirosina Quinases/antagonistas & inibidores , Animais , Córtex Cerebral/efeitos dos fármacos , Córtex Cerebral/embriologia , Córtex Cerebral/patologia , Cognição/efeitos dos fármacos , Ciclina D1/metabolismo , Giro Denteado/efeitos dos fármacos , Giro Denteado/patologia , Síndrome de Down/patologia , Síndrome de Down/psicologia , Feminino , Células HEK293 , Humanos , Aprendizagem/efeitos dos fármacos , Masculino , Camundongos , Células-Tronco Neurais/patologia , Gravidez , Proteínas Serina-Treonina Quinases/metabolismo , Proteínas Tirosina Quinases/metabolismo , Quinases DyrkRESUMO
A facile method for preparing diverse aryne-nickel complexes from readily synthesized ortho-borylaryl triflates is described. Exploratory synthetic applications, including the synthesis of 1,2-difunctionalized arenes, based on the nucleophilic character of the aryne-nickel complexes are also demonstrated.
RESUMO
Autophosphorylation of amino-acid residues is part of the folding process of various protein kinases. Conventional chemical screening of mature kinases has missed inhibitors that selectively interfere with the folding process. Here we report a cell-based assay that evaluates inhibition of a kinase at a transitional state during the folding process and identify a folding intermediate-selective inhibitor of dual-specificity tyrosine-phosphorylation-regulated kinase 1A (DYRK1A), which we refer to as FINDY. FINDY suppresses intramolecular autophosphorylation of Ser97 in DYRK1A in cultured cells, leading to its degradation, but does not inhibit substrate phosphorylation catalysed by the mature kinase. FINDY also suppresses Ser97 autophosphorylation of recombinant DYRK1A, suggesting direct inhibition, and shows high selectivity for DYRK1A over other DYRK family members. In addition, FINDY rescues DYRK1A-induced developmental malformations in Xenopus laevis embryos. Our study demonstrates that transitional folding intermediates of protein kinases can be targeted by small molecules, and paves the way for developing novel types of kinase inhibitors.
Assuntos
Bioensaio , Dobramento de Proteína/efeitos dos fármacos , Inibidores de Proteínas Quinases/farmacologia , Proteínas Serina-Treonina Quinases/antagonistas & inibidores , Proteínas Tirosina Quinases/antagonistas & inibidores , Tiazóis/farmacologia , Sequência de Aminoácidos , Animais , Biomarcadores/metabolismo , Cantaridina/farmacologia , Embrião não Mamífero , Regulação da Expressão Gênica no Desenvolvimento , Células HEK293 , Humanos , Toxinas Marinhas , Dados de Sequência Molecular , Ácido Okadáico/farmacologia , Oxazóis/farmacologia , Fosforilação/efeitos dos fármacos , Plasmídeos/química , Plasmídeos/metabolismo , Inibidores de Proteínas Quinases/química , Proteínas Serina-Treonina Quinases/química , Proteínas Serina-Treonina Quinases/genética , Proteínas Serina-Treonina Quinases/metabolismo , Proteínas Tirosina Quinases/química , Proteínas Tirosina Quinases/genética , Proteínas Tirosina Quinases/metabolismo , Proteínas Recombinantes , Alinhamento de Sequência , Tiazóis/química , Transfecção , Xenopus laevis/embriologia , Quinases DyrkRESUMO
The protein kinase family includes attractive targets for drug development. Methods for screening of kinase inhibitors remain largely limited to in vitro catalytic assays. It has been shown that ATP-competitive inhibitors antagonize interaction between the target kinase and kinase-specific co-chaperone CDC37 in living cells. Here we show a cell-based method to screen kinase inhibitors using fusion protein of CDC37 with a mutated catalytic 19-kDa component of Oplophorus luciferase, nanoKAZ (CDC37-nanoKAZ). A dual-specificity kinase DYRK1A, an importance of which has been highlighted in Alzheimer's disease, was targeted in this study. We established 293T cells stably expressing CDC37-nanoKAZ, and analyzed interaction between CDC37-nanoKAZ and DYRK1A. We revealed that DYRK1A interacted with CDC37-nanoKAZ. Importantly, point mutations that affect autophosphorylation strengthened the interaction, thus improving signal/noise ratio of the interaction relative to non-specific binding of CDC37-nanoKAZ. This high signal/noise ratio enabled screening of chemical library that resulted in identification of a potent inhibitor of DYRK1A, named CaNDY. CaNDY induced selective degradation of DYRK1A, and inhibited catalytic activity of recombinant DYRK1A with IC50 value of 7.9 nM by competing with ATP. This method based on a mutant target kinase and a bioluminescence-eliciting co-chaperone CDC37 could be applicable to evaluation and development of inhibitors targeting other kinases.
Assuntos
Proteínas de Ciclo Celular/genética , Chaperoninas/genética , Avaliação Pré-Clínica de Medicamentos/métodos , Luciferases/genética , Inibidores de Proteínas Quinases/farmacologia , Proteínas Serina-Treonina Quinases/antagonistas & inibidores , Proteínas Tirosina Quinases/antagonistas & inibidores , Benzofuranos/farmacologia , Proteínas de Ciclo Celular/metabolismo , Chaperoninas/metabolismo , Células HEK293 , Proteínas de Choque Térmico HSP90/genética , Proteínas de Choque Térmico HSP90/metabolismo , Humanos , Luciferases/metabolismo , Chaperonas Moleculares/genética , Mutação , Proteínas Serina-Treonina Quinases/genética , Proteínas Serina-Treonina Quinases/metabolismo , Proteínas Tirosina Quinases/genética , Proteínas Tirosina Quinases/metabolismo , Proteínas Recombinantes de Fusão/genética , Proteínas Recombinantes de Fusão/metabolismo , Bibliotecas de Moléculas Pequenas/farmacologia , Tiazolidinas/farmacologia , Triazóis/farmacologia , Quinases DyrkRESUMO
Dysregulation of dual-specificity tyrosine-phosphorylation-regulated kinase 1A (DYRK1A) has been demonstrated in several pathological conditions, including Alzheimer's disease and cancer progression. It has been recently reported that a gain of function-mutation in the human DYRK1B gene exacerbates metabolic syndrome by enhancing obesity. In the previous study, we developed an inhibitor of DYRK family kinases (INDY) and demonstrated that INDY suppresses the pathological phenotypes induced by overexpression of DYRK1A or DYRK1B in cellular and animal models. In this study, we designed and synthesized a novel inhibitor of DYRK family kinases based on the crystal structure of the DYRK1A/INDY complex by replacing the phenol group of INDY with dibenzofuran to produce a derivative, named BINDY. This compound exhibited potent and selective inhibitory activity toward DYRK family kinases in an in vitro assay. Furthermore, treatment of 3T3-L1 pre-adipocytes with BINDY hampered adipogenesis by suppressing gene expression of the critical transcription factors PPARγ and C/EBPα. This study indicates the possibility of BINDY as a potential drug for metabolic syndrome.
Assuntos
Benzofuranos/síntese química , Benzotiazóis/síntese química , Desenho de Fármacos , Inibidores de Proteínas Quinases/síntese química , Proteínas Serina-Treonina Quinases/antagonistas & inibidores , Proteínas Tirosina Quinases/antagonistas & inibidores , Células 3T3-L1 , Adipogenia/efeitos dos fármacos , Animais , Benzofuranos/química , Benzofuranos/toxicidade , Benzotiazóis/química , Benzotiazóis/toxicidade , Sítios de Ligação , Proteína alfa Estimuladora de Ligação a CCAAT/genética , Proteína alfa Estimuladora de Ligação a CCAAT/metabolismo , Humanos , Camundongos , Simulação de Acoplamento Molecular , PPAR gama/genética , PPAR gama/metabolismo , Inibidores de Proteínas Quinases/química , Inibidores de Proteínas Quinases/toxicidade , Proteínas Serina-Treonina Quinases/genética , Proteínas Serina-Treonina Quinases/metabolismo , Estrutura Terciária de Proteína , Proteínas Tirosina Quinases/genética , Proteínas Tirosina Quinases/metabolismo , Quinases DyrkRESUMO
An efficient synthetic method for versatile dibenzoxaborins based on boron-selective Suzuki-Miyaura cross-coupling between o-borylphenols and aryl halides or triflates bearing a 1,8-diaminonaphthalene-protected o-boryl group is reported. A short synthesis of defucogilvocarcin M was achieved using the proposed method in combination with several other boron-mediated transformations.