RESUMO
Dynamic changes in protein-protein interaction (PPI) networks underlie all physiological cellular functions and drive devastating human diseases. Profiling PPI networks can, therefore, provide critical insight into disease mechanisms and identify new drug targets. Kinases are regulatory nodes in many PPI networks; yet, facile methods to systematically study kinase interactome dynamics are lacking. We describe kinobead competition and correlation analysis (kiCCA), a quantitative mass spectrometry-based chemoproteomic method for rapid and highly multiplexed profiling of endogenous kinase interactomes. Using kiCCA, we identified 1,154 PPIs of 238 kinases across 18 diverse cancer lines, quantifying context-dependent kinase interactome changes linked to cancer type, plasticity, and signaling states, thereby assembling an extensive knowledgebase for cell signaling research. We discovered drug target candidates, including an endocytic adapter-associated kinase (AAK1) complex that promotes cancer cell epithelial-mesenchymal plasticity and drug resistance. Our data demonstrate the importance of kinase interactome dynamics for cellular signaling in health and disease.
Assuntos
Neoplasias , Humanos , Transdução de Sinais , Mapas de Interação de ProteínasRESUMO
Depending on endoplasmic reticulum (ER) stress levels, the ER transmembrane multidomain protein IRE1α promotes either adaptation or apoptosis. Unfolded ER proteins cause IRE1α lumenal domain homo-oligomerization, inducing trans autophosphorylation that further drives homo-oligomerization of its cytosolic kinase/endoribonuclease (RNase) domains to activate mRNA splicing of adaptive XBP1 transcription factor. However, under high/chronic ER stress, IRE1α surpasses an oligomerization threshold that expands RNase substrate repertoire to many ER-localized mRNAs, leading to apoptosis. To modulate these effects, we developed ATP-competitive IRE1α Kinase-Inhibiting RNase Attenuators-KIRAs-that allosterically inhibit IRE1α's RNase by breaking oligomers. One optimized KIRA, KIRA6, inhibits IRE1α in vivo and promotes cell survival under ER stress. Intravitreally, KIRA6 preserves photoreceptor functional viability in rat models of ER stress-induced retinal degeneration. Systemically, KIRA6 preserves pancreatic ß cells, increases insulin, and reduces hyperglycemia in Akita diabetic mice. Thus, IRE1α powerfully controls cell fate but can itself be controlled with small molecules to reduce cell degeneration.
Assuntos
Estresse do Retículo Endoplasmático , Endorribonucleases/antagonistas & inibidores , Inibidores de Proteínas Quinases/farmacologia , Proteínas Serina-Treonina Quinases/antagonistas & inibidores , Regulação Alostérica , Animais , Apoptose/efeitos dos fármacos , Linhagem Celular , Endorribonucleases/química , Endorribonucleases/metabolismo , Ativação Enzimática/efeitos dos fármacos , Humanos , Ilhotas Pancreáticas/metabolismo , Masculino , Camundongos , Proteínas Serina-Treonina Quinases/química , Proteínas Serina-Treonina Quinases/metabolismo , Ratos , Retina/metabolismo , Ribonucleases/antagonistas & inibidoresRESUMO
Multiple layers of regulation modulate the activity and localization of protein kinases. However, many details of kinase regulation remain incompletely understood. Here, we apply saturation mutagenesis and a chemical genetic method for allosterically modulating kinase global conformation to Src kinase, providing insight into known regulatory mechanisms and revealing a previously undiscovered interaction between Src's SH4 and catalytic domains. Abrogation of this interaction increased phosphotransferase activity, promoted membrane association, and provoked phosphotransferase-independent alterations in cell morphology. Thus, Src's SH4 domain serves as an intramolecular regulator coupling catalytic activity, global conformation, and localization, as well as mediating a phosphotransferase-independent function. Sequence conservation suggests that the SH4 domain regulatory interaction exists in other Src-family kinases. Our combined approach's ability to reveal a regulatory mechanism in one of the best-studied kinases suggests that it could be applied broadly to provide insight into kinase structure, regulation, and function.
Assuntos
Domínio Catalítico/genética , Mutagênese/genética , Conformação Proteica , Quinases da Família src/química , Regulação Alostérica/genética , Membrana Celular/química , Membrana Celular/enzimologia , Células HEK293 , Humanos , Fosforilação , Quinases da Família src/genéticaRESUMO
Clinical resistance to rat sarcoma virus (Ras)-G12C inhibitors is a challenge. A subpopulation of cancer cells has been shown to undergo genomic and transcriptional alterations to facilitate drug resistance but the immediate adaptive effects on Ras signaling in response to these drugs at the single-cell level is not well understood. Here, we used Ras biosensors to profile the activity and signaling environment of endogenous Ras at the single-cell level. We found that a subpopulation of KRas-G12C cells treated with Ras-G12C-guanosine-diphosphate inhibitors underwent adaptive signaling and metabolic changes driven by wild-type Ras at the Golgi and mutant KRas at the mitochondria, respectively. Our Ras biosensors identified major vault protein as a mediator of Ras activation through its scaffolding of Ras signaling pathway components and metabolite channels. Overall, methods including ours that facilitate direct analysis on the single-cell level can report the adaptations that subpopulations of cells adopt in response to cancer therapies, thus providing insight into drug resistance.
RESUMO
CRISPR-Cas9 has yielded a plethora of effectors, including targeted transcriptional activators, base editors and prime editors. Current approaches for inducibly modulating Cas9 activity lack temporal precision and require extensive screening and optimization. We describe a versatile, chemically controlled and rapidly activated single-component DNA-binding Cas9 switch, ciCas9, which we use to confer temporal control over seven Cas9 effectors, including two cytidine base editors, two adenine base editors, a dual base editor, a prime editor and a transcriptional activator. Using these temporally controlled effectors, we analyze base editing kinetics, showing that editing occurs within hours and that rapid early editing of nucleotides predicts eventual editing magnitude. We also reveal that editing at preferred nucleotides within target sites increases the frequency of bystander edits. Thus, the ciCas9 switch offers a simple, versatile approach to generating chemically controlled Cas9 effectors, informing future effector engineering and enabling precise temporal effector control for kinetic studies.
Assuntos
Sistemas CRISPR-Cas , Edição de Genes , Cinética , Nucleotídeos , AdeninaRESUMO
The unfolded protein response (UPR) homeostatically matches endoplasmic reticulum (ER) protein-folding capacity to cellular secretory needs. However, under high or chronic ER stress, the UPR triggers apoptosis. This cell fate dichotomy is promoted by differential activation of the ER transmembrane kinase/endoribonuclease (RNase) IRE1α. We previously found that the RNase of IRE1α can be either fully activated or inactivated by ATP-competitive kinase inhibitors. Here we developed kinase inhibitors, partial antagonists of IRE1α RNase (PAIRs), that partially antagonize the IRE1α RNase at full occupancy. Biochemical and structural studies show that PAIRs promote partial RNase antagonism by intermediately displacing the helix αC in the IRE1α kinase domain. In insulin-producing ß-cells, PAIRs permit adaptive splicing of Xbp1 mRNA while quelling destructive ER mRNA endonucleolytic decay and apoptosis. By preserving Xbp1 mRNA splicing, PAIRs allow B cells to differentiate into immunoglobulin-producing plasma cells. Thus, an intermediate RNase-inhibitory 'sweet spot', achieved by PAIR-bound IRE1α, captures a desirable conformation for drugging this master UPR sensor/effector.
Assuntos
Trifosfato de Adenosina/farmacologia , Endorribonucleases/antagonistas & inibidores , Inibidores de Proteínas Quinases/farmacologia , Proteínas Serina-Treonina Quinases/antagonistas & inibidores , Trifosfato de Adenosina/química , Endorribonucleases/metabolismo , Humanos , Modelos Moleculares , Estrutura Molecular , Inibidores de Proteínas Quinases/química , Proteínas Serina-Treonina Quinases/metabolismo , Desdobramento de Proteína/efeitos dos fármacosRESUMO
Kinase-catalyzed protein phosphorylation is fundamental to eukaryotic signal transduction, regulating most cellular processes. Kinases are frequently dysregulated in cancer, inflammation, and degenerative diseases, and because they can be inhibited with small molecules, they became important drug targets. Accordingly, analytical approaches that determine kinase activation states are critically important to understand kinase-dependent signal transduction and to identify novel drug targets and predictive biomarkers. Multiplexed inhibitor beads (MIBs or kinobeads) efficiently enrich kinases from cell lysates for liquid chromatography-mass spectrometry (LC-MS) analysis. When combined with phosphopeptide enrichment, kinobead/LC-MS can also quantify the phosphorylation state of kinases, which determines their activation state. However, an efficient kinobead/LC-MS kinase phospho-profiling protocol that allows routine analyses of cell lines and tissues has not yet been developed. Here, we present a facile workflow that quantifies the global phosphorylation state of kinases with unprecedented sensitivity. We also found that our kinobead/LC-MS protocol can measure changes in kinase complex composition and show how these changes can indicate kinase activity. We demonstrate the utility of our approach in specifying kinase signaling pathways that control the acute steroidogenic response in Leydig cells; this analysis establishes the first comprehensive framework for the post-translational control of steroid biosynthesis.
Assuntos
Transdução de Sinais , Espectrometria de Massas em Tandem , Cromatografia Líquida , Humanos , Masculino , Fosforilação , Proteínas Quinases/metabolismoRESUMO
We developed a chemically inducible Cas9 (ciCas9) and a droplet digital PCR assay for double-strand breaks (DSB-ddPCR) to investigate the kinetics of Cas9-mediated generation and repair of DSBs in cells. ciCas9 is a rapidly activated, single-component Cas9 variant engineered by replacing the protein's REC2 domain with the BCL-xL protein and fusing an interacting BH3 peptide to the C terminus. ciCas9 can be tunably activated by a compound that disrupts the BCL-xL-BH3 interaction within minutes. DSB-ddPCR demonstrates time-resolved, highly quantitative, and targeted measurement of DSBs. Combining these tools facilitated an unprecedented exploration of the kinetics of Cas9-mediated DNA cleavage and repair. We find that sgRNAs targeting different sites generally induce cleavage within minutes and repair within 1 or 2 h. However, we observe distinct kinetic profiles, even for proximal sites, and this suggests that target sequence and chromatin state modulate cleavage and repair kinetics.
Assuntos
Caspase 9/genética , Quebras de DNA de Cadeia Dupla , Sondas de DNA/genética , Edição de Genes/métodos , Técnicas de Sonda Molecular , Reação em Cadeia da Polimerase/métodos , CinéticaRESUMO
Recent studies have illustrated the burden Cryptosporidium infection places on the lives of malnourished children and immunocompromised individuals. Treatment options remain limited, and efforts to develop a new therapeutic are currently underway. However, there are unresolved questions about the ideal pharmacokinetic characteristics of new anti-Cryptosporidium therapeutics. Specifically, should drug developers optimize therapeutics and formulations to increase drug exposure in the gastrointestinal lumen, enterocytes, or systemic circulation? Furthermore, how should researchers interpret data suggesting their therapeutic is a drug efflux transporter substrate? In vivo drug transporter-mediated alterations in efficacy are well recognized in multiple disease areas, but the impact of intestinal transporters on therapeutic efficacy against enteric diseases has not been established. Using multiple in vitro models and a mouse model of Cryptosporidium infection, we characterized the effect of P-glycoprotein efflux on bumped kinase inhibitor pharmacokinetics and efficacy. Our results demonstrated P-glycoprotein decreases bumped kinase inhibitor enterocyte exposure, resulting in reduced in vivo efficacy against Cryptosporidium. Furthermore, a hollow fiber model of Cryptosporidium infection replicated the in vivo impact of P-glycoprotein on anti-Cryptosporidium efficacy. In conclusion, when optimizing drug candidates targeting the gastrointestinal epithelium or gastrointestinal epithelial infections, drug developers should consider the adverse impact of active efflux transporters on efficacy.
Assuntos
Membro 1 da Subfamília B de Cassetes de Ligação de ATP/metabolismo , Criptosporidiose/tratamento farmacológico , Cryptosporidium/efeitos dos fármacos , Enteropatias Parasitárias/tratamento farmacológico , Naftalenos/metabolismo , Naftalenos/uso terapêutico , Piperidinas/metabolismo , Piperidinas/uso terapêutico , Pirazóis/metabolismo , Pirazóis/uso terapêutico , Pirimidinas/metabolismo , Pirimidinas/uso terapêutico , Quinolinas/metabolismo , Quinolinas/uso terapêutico , Animais , Transporte Biológico Ativo , Células CACO-2 , Permeabilidade da Membrana Celular/efeitos dos fármacos , Criptosporidiose/parasitologia , Modelos Animais de Doenças , Descoberta de Drogas/métodos , Enterócitos/efeitos dos fármacos , Enterócitos/metabolismo , Enterócitos/parasitologia , Feminino , Absorção Gastrointestinal/efeitos dos fármacos , Humanos , Interferon gama/genética , Camundongos , Camundongos Knockout , Naftalenos/química , Piperidinas/química , Pirazóis/química , Pirimidinas/química , Quinolinas/química , Resultado do TratamentoRESUMO
Bumped kinase inhibitors (BKIs) have been shown to be potent inhibitors of Toxoplasma gondii calcium-dependent protein kinase 1. Pyrazolopyrimidine and 5-aminopyrazole-4-carboxamide scaffold-based BKIs are effective in acute and chronic experimental models of toxoplasmosis. Through further exploration of these 2 scaffolds and a new pyrrolopyrimidine scaffold, additional compounds have been identified that are extremely effective against acute experimental toxoplasmosis. The in vivo efficacy of these BKIs demonstrates that the cyclopropyloxynaphthyl, cyclopropyloxyquinoline, and 2-ethoxyquinolin-6-yl substituents are associated with efficacy across scaffolds. In addition, a broad range of plasma concentrations after oral dosing resulted from small structural changes to the BKIs. These select BKIs include anti-Toxoplasma compounds that are effective against acute experimental toxoplasmosis and are not toxic in human cell assays, nor to mice when administered for therapy. The BKIs described here are promising late leads for improving anti-Toxoplasma therapy.
Assuntos
Inibidores de Proteínas Quinases/uso terapêutico , Proteínas de Protozoários/antagonistas & inibidores , Pirazóis/uso terapêutico , Pirimidinas/uso terapêutico , Toxoplasmose Animal/tratamento farmacológico , Toxoplasmose Cerebral/tratamento farmacológico , Administração Oral , Animais , Área Sob a Curva , Feminino , Técnicas In Vitro , Camundongos , Inibidores de Proteínas Quinases/sangue , Inibidores de Proteínas Quinases/farmacologia , Pirazóis/sangue , Pirazóis/farmacologia , Pirimidinas/sangue , Pirimidinas/farmacologiaRESUMO
Chemical methods that allow the spatial proximity of proteins to be temporally modulated are powerful tools for studying biology and engineering synthetic cellular behaviors. Here, we describe a new chemically controlled method for rapidly disrupting the interaction between two basally colocalized protein binding partners. Our chemically disrupted proximity (CDP) system is based on the interaction between the hepatitis C virus protease (HCVp) NS3a and a genetically encoded peptide inhibitor. Using clinically approved antiviral inhibitors as chemical disrupters of the NS3a/peptide interaction, we demonstrate that our CDP system can be used to confer temporal control over diverse intracellular processes. This NS3a-based CDP system represents a new modality for engineering chemical control over intracellular protein function that is complementary to currently available techniques.
Assuntos
Inibidores de Proteases/farmacologia , Proteínas não Estruturais Virais/antagonistas & inibidores , Fenômenos Fisiológicos Celulares , Células HEK293 , Hepacivirus/efeitos dos fármacos , Hepacivirus/enzimologia , Humanos , Inibidores de Proteases/química , Proteínas não Estruturais Virais/química , Proteínas não Estruturais Virais/metabolismoRESUMO
Small molecule inhibitors often only block a subset of the cellular functions of their protein targets. In many cases, how inhibiting only a portion of a multifunctional protein's functions affects the state of the cell is not well-understood. Therefore, tools that allow the systematic characterization of the cellular interactions that inhibitor-bound proteins make would be of great utility, especially for multifunctional proteins. Here, we describe a chemoproteomic strategy for interrogating the cellular localization and interactomes of inhibitor-bound kinases. By developing a set of orthogonal inhibitors that contain a trans-cyclooctene (TCO) click handle, we are able to enrich and characterize the proteins complexed to a drug-sensitized variant of the multidomain kinase Src. We show that Src's cellular interactions are highly influenced by the intermolecular accessibility of its regulatory domains, which can be allosterically modulated through its ATP-binding site. Furthermore, we find that the signaling status of the cell also has a large effect on Src's interactome. Finally, we demonstrate that our TCO-conjugated probes can be used as a part of a proximity ligation assay to study Src's localization and interactions in situ. Together, our chemoproteomic strategy represents a comprehensive method for studying the localization and interactomes of inhibitor-bound kinases and, potentially, other druggable protein targets.
Assuntos
Ciclo-Octanos/farmacologia , Inibidores de Proteínas Quinases/farmacologia , Quinases da Família src/antagonistas & inibidores , Ciclo-Octanos/química , Células HEK293 , Humanos , Estrutura Molecular , Inibidores de Proteínas Quinases/química , Quinases da Família src/química , Quinases da Família src/metabolismoRESUMO
Synthetic protein switches controlled with user-defined inputs are powerful tools for studying and controlling dynamic cellular processes. To date, these approaches have relied primarily on intermolecular regulation. Here we report a computationally guided framework for engineering intramolecular regulation of protein function. We utilize this framework to develop chemically inducible activator of RAS (CIAR), a single-component RAS rheostat that directly activates endogenous RAS in response to a small molecule. Using CIAR, we show that direct RAS activation elicits markedly different RAS-ERK signaling dynamics from growth factor stimulation, and that these dynamics differ among cell types. We also found that the clinically approved RAF inhibitor vemurafenib potently primes cells to respond to direct wild-type RAS activation. These results demonstrate the utility of CIAR for quantitatively interrogating RAS signaling. Finally, we demonstrate the general utility of our approach in design of intramolecularly regulated protein tools by applying it to the Rho family of guanine nucleotide exchange factors.
Assuntos
MAP Quinases Reguladas por Sinal Extracelular/metabolismo , Sistema de Sinalização das MAP Quinases , Engenharia de Proteínas , Proteínas ras/química , Proteínas ras/metabolismo , Linhagem Celular , Humanos , Modelos MolecularesRESUMO
The c-Jun N-terminal kinases (JNKs) play a wide variety of roles in cellular signaling processes, dictating important, and even divergent, cellular fates. These essential kinases possess docking surfaces distal to their active sites that interact with diverse binding partners, including upstream activators, downstream substrates, and protein scaffolds. Prior studies have suggested that the interactions of certain protein-binding partners with one such JNK docking surface, termed the D-recruitment site (DRS), can allosterically influence the conformational state of the ATP-binding pocket of JNKs. To further explore the allosteric relationship between the ATP-binding pockets and DRSs of JNKs, we investigated how the interactions of the scaffolding protein JIP1, as well as the upstream activators MKK4 and MKK7, are allosterically influenced by the ATP-binding site occupancy of the JNKs. We show that the affinity of the JNKs for JIP1 can be divergently modulated with ATP-competitive inhibitors, with a >50-fold difference in dissociation constant observed between the lowest- and highest-affinity JNK1-inhibitor complexes. Furthermore, we found that we could promote or attenuate phosphorylation of JNK1's activation loop by MKK4 and MKK7, by varying the ATP-binding site occupancy. Given that JIP1, MKK4, and MKK7 all interact with JNK DRSs, these results demonstrate that there is functional allostery between the ATP-binding sites and DRSs of these kinases. Furthermore, our studies suggest that ATP-competitive inhibitors can allosterically influence the intracellular binding partners of the JNKs.
Assuntos
Trifosfato de Adenosina , Proteínas Quinases JNK Ativadas por Mitógeno , Sistema de Sinalização das MAP Quinases , Simulação de Acoplamento Molecular , Inibidores de Proteínas Quinases/química , Trifosfato de Adenosina/análogos & derivados , Trifosfato de Adenosina/química , Animais , Sítios de Ligação , Domínio Catalítico , Humanos , Proteínas Quinases JNK Ativadas por Mitógeno/antagonistas & inibidores , Proteínas Quinases JNK Ativadas por Mitógeno/química , Estrutura Secundária de ProteínaRESUMO
In Toxoplasma gondii, calcium-dependent protein kinase 1 (CDPK1) is an essential protein kinase required for invasion of host cells. We have developed several hundred CDPK1 inhibitors, many of which block invasion. Inhibitors with similar 50% inhibitory concentrations (IC50s) were tested in thermal shift assays for their ability to stabilize CDPK1 in cell lysates, in intact cells, or in purified form. Compounds that inhibited parasite growth stabilized CDPK1 in all assays. In contrast, two compounds that showed poor growth inhibition stabilized CDPK1 in lysates but not in cells. Thus, cellular exclusion could explain exceptions in the correlation between the action on the target and cellular activity. We used thermal shift assays to examine CDPK1 in two clones that were independently selected by growth in the CDPK1 inhibitor RM-1-132 and that had increased 50% effective concentrations (EC50s) for the compound. The A and C clones had distinct point mutations in the CDPK1 kinase domain, H201Q and L96P, respectively, residues that lie near one another in the inactive isoform. Purified mutant proteins showed RM-1-132 IC50s and thermal shifts similar to those shown by wild-type CDPK1. Reduced inhibitor stabilization (and a presumed reduced interaction) was observed only in cellular thermal shift assays. This highlights the utility of cellular thermal shift assays in demonstrating that resistance involves reduced on-target engagement (even if biochemical assays suggest otherwise). Indeed, similar EC50s were observed upon overexpression of the mutant proteins, as in the corresponding drug-selected parasites, although high levels of CDPK1(H201Q) only modestly increased resistance compared to that achieved with high levels of wild-type enzyme.
Assuntos
Quinase 2 de Adesão Focal/antagonistas & inibidores , Naftalenos/farmacologia , Piperidinas/farmacologia , Inibidores de Proteínas Quinases/farmacologia , Pirazóis/farmacologia , Toxoplasma/efeitos dos fármacos , Toxoplasmose/tratamento farmacológico , Animais , Resistência a Medicamentos/genética , Quinase 2 de Adesão Focal/genética , Humanos , Proteínas de Protozoários/antagonistas & inibidores , Proteínas de Protozoários/genética , Toxoplasma/genéticaRESUMO
There is a substantial need for novel therapeutics to combat the widespread impact caused by Crytosporidium infection. However, there is a lack of knowledge as to which drug pharmacokinetic (PK) characteristics are key to generate an in vivo response, specifically whether systemic drug exposure is crucial for in vivo efficacy. To identify which PK properties are correlated with in vivo efficacy, we generated physiologically based PK models to simulate systemic and gastrointestinal drug concentrations for a series of bumped kinase inhibitors (BKIs) that have nearly identical in vitro potency against Cryptosporidium but display divergent PK properties. When BKI concentrations were used to predict in vivo efficacy with a neonatal model of Cryptosporidium infection, these concentrations in the large intestine were the sole predictors of the observed in vivo efficacy. The significance of large intestinal BKI exposure for predicting in vivo efficacy was further supported with an adult mouse model of Cryptosporidium infection. This study suggests that drug exposure in the large intestine is essential for generating a superior in vivo response, and that physiologically based PK models can assist in the prioritization of leading preclinical drug candidates for in vivo testing.
Assuntos
Criptosporidiose/tratamento farmacológico , Trato Gastrointestinal/efeitos dos fármacos , Inibidores de Proteínas Quinases/farmacocinética , Animais , Cryptosporidium parvum/efeitos dos fármacos , Cryptosporidium parvum/isolamento & purificação , Modelos Animais de Doenças , Relação Dose-Resposta a Droga , Feminino , Trato Gastrointestinal/metabolismo , Concentração Inibidora 50 , Camundongos , Camundongos Knockout , Modelos Teóricos , Naftalenos/farmacocinética , Piperidinas/farmacocinética , Inibidores de Proteínas Quinases/sangue , Pirazóis/farmacocinéticaRESUMO
Bumped kinase inhibitors (BKIs) of Cryptosporidium parvum calcium-dependent protein kinase 1 (CpCDPK1) are leading candidates for treatment of cryptosporidiosis-associated diarrhea. Potential cardiotoxicity related to anti-human ether-à-go-go potassium channel (hERG) activity of the first-generation anti-Cryptosporidium BKIs triggered further testing for efficacy. A luminescence assay adapted for high-throughput screening was used to measure inhibitory activities of BKIs against C. parvum in vitro. Furthermore, neonatal and interferon γ knockout mouse models of C. parvum infection identified BKIs with in vivo activity. Additional iterative experiments for optimum dosing and selecting BKIs with minimum levels of hERG activity and frequencies of other safety liabilities included those that investigated mammalian cell cytotoxicity, C. parvum proliferation inhibition in vitro, anti-human Src inhibition, hERG activity, in vivo pharmacokinetic data, and efficacy in other mouse models. Findings of this study suggest that fecal concentrations greater than parasite inhibitory concentrations correlate best with effective therapy in the mouse model of cryptosporidiosis, but a more refined model for efficacy is needed.
Assuntos
Antiprotozoários/administração & dosagem , Criptosporidiose/tratamento farmacológico , Cryptosporidium parvum/efeitos dos fármacos , Inibidores de Proteínas Quinases/administração & dosagem , Administração Oral , Animais , Diarreia/tratamento farmacológico , Modelos Animais de Doenças , Feminino , Camundongos , Camundongos Knockout , Camundongos SCIDRESUMO
ATP-competitive protein kinase inhibitors are important research tools and therapeutic agents. Because there are >500 human kinases that contain highly conserved active sites, the development of selective inhibitors is extremely challenging. Methods to rapidly and efficiently profile kinase inhibitor targets in cell lysates are urgently needed to discover selective compounds and to elucidate the mechanisms of action for polypharmacological inhibitors. Here, we describe a protocol for microgram-scale chemoproteomic profiling of ATP-competitive kinase inhibitors using kinobeads. We employed a gel-free in situ digestion protocol coupled to nanoflow liquid chromatography-mass spectrometry to profile â¼200 kinases in single analytical runs using as little as 5 µL of kinobeads and 300 µg of protein. With our kinobead reagents, we obtained broad coverage of the kinome, monitoring the relative expression levels of 312 kinases in a diverse panel of 11 cancer cell lines. Further, we profiled a set of pyrrolopyrimidine- and pyrazolopyrimidine-based kinase inhibitors in competition-binding experiments with label-free quantification, leading to the discovery of a novel selective and potent inhibitor of protein kinase D (PKD) 1, 2, and 3. Our protocol is useful for rapid and sensitive profiling of kinase expression levels and ATP-competitive kinase inhibitor selectivity in native proteomes.
Assuntos
Proteína Quinase C/antagonistas & inibidores , Inibidores de Proteínas Quinases/análise , Proteômica/métodos , Antineoplásicos , Ligação Competitiva , Linhagem Celular Tumoral , Cromatografia Líquida , Humanos , Espectrometria de Massas/métodos , Proteínas Quinases/análise , Pirimidinas/farmacologia , Pirimidinas/uso terapêutico , Pirróis/farmacologia , Pirróis/uso terapêutico , Frações Subcelulares/químicaRESUMO
We present the effects of two novel bumped kinase inhibitors, BKI-1517 and BKI-1553, against Neospora caninum tachyzoites in vitro and in experimentally infected pregnant mice. These compounds inhibited tachyzoite proliferation of a transgenic beta-galactosidase reporter strain cultured in human foreskin fibroblasts with 50% inhibitory concentrations (IC50s) of 0.05 ± 0.03 and 0.18 ± 0.03 µM, respectively. As assessed by an alamarBlue assay, fibroblast IC50s were above 20 µM; however, morphological changes occurred in cultures treated with >5 µM BKI-1517 after prolonged exposure (>6 days). Treatment of intracellular tachyzoites with 5 µM BKI-1553 for 6 days inhibited endodyogeny by interfering with the separation of newly formed zoites from a larger multinucleated parasite mass. In contrast, parasites treated with 5 µM BKI-1517 did not form large complexes and showed much more evidence of cell death. However, after a treatment duration of 10 days in vitro, both compounds failed to completely prevent the regrowth of parasites from culture. BALB/c mice experimentally infected with N. caninum Spain7 (Nc-Spain7) and then treated during 6 days with BKI-1517 or BKI-1553 at different dosages showed a significant reduction of the cerebral parasite load. However, fertility was impaired by BKI-1517 when applied at 50 mg/kg of body weight/day. At 20 mg/kg/day, BKI-1517 significantly inhibited the vertical transmission of N. caninum to pups and increased the rate of survival of offspring. BKI-1553 was less detrimental to fertility and also provided significant but clearly less pronounced protection of dams and offspring. These results demonstrate that, when judiciously applied, this compound class protects offspring from vertical transmission and disease.
Assuntos
Coccidiose/tratamento farmacológico , Coccidiostáticos/farmacologia , Transmissão Vertical de Doenças Infecciosas/prevenção & controle , Estágios do Ciclo de Vida/efeitos dos fármacos , Neospora/efeitos dos fármacos , Inibidores de Proteínas Quinases/farmacologia , Pirazóis/farmacologia , Pirimidinas/farmacologia , Quinolinas/farmacologia , Animais , Encéfalo/efeitos dos fármacos , Encéfalo/parasitologia , Proliferação de Células/efeitos dos fármacos , Coccidiose/parasitologia , Coccidiose/transmissão , Coccidiostáticos/química , Feminino , Fertilidade/efeitos dos fármacos , Fibroblastos/efeitos dos fármacos , Fibroblastos/parasitologia , Expressão Gênica , Genes Reporter , Humanos , Estágios do Ciclo de Vida/fisiologia , Camundongos , Camundongos Endogâmicos BALB C , Neospora/enzimologia , Neospora/genética , Neospora/crescimento & desenvolvimento , Oxazinas , Gravidez , Cultura Primária de Células , Inibidores de Proteínas Quinases/química , Proteínas Quinases/genética , Proteínas Quinases/metabolismo , Proteínas de Protozoários/antagonistas & inibidores , Proteínas de Protozoários/genética , Proteínas de Protozoários/metabolismo , Pirazóis/química , Pirimidinas/química , Quinolinas/química , Xantenos , beta-Galactosidase/genética , beta-Galactosidase/metabolismoRESUMO
Cryptosporidium parvum calcium-dependent protein kinase 1 (CpCDPK1) is a promising target for drug development against cryptosporidiosis. We report a series of low-nanomolar CpCDPK1 5-aminopyrazole-4-carboxamide (AC) scaffold inhibitors that also potently inhibit C. parvum growth in vitro Correlation between anti-CpCDPK1 and C. parvum growth inhibition, as previously reported for pyrazolopyrimidines, was not apparent. Nonetheless, lead AC compounds exhibited a substantial reduction of parasite burden in the neonatal mouse cryptosporidiosis model when dosed at 25 mg/kg.