RESUMEN
The requirement for next-generation antimalarials to be both curative and transmission-blocking necessitates the identification of previously undiscovered druggable molecular pathways. We identified a selective inhibitor of the Plasmodium falciparum protein kinase PfCLK3, which we used in combination with chemogenetics to validate PfCLK3 as a drug target acting at multiple parasite life stages. Consistent with a role for PfCLK3 in RNA splicing, inhibition resulted in the down-regulation of more than 400 essential parasite genes. Inhibition of PfCLK3 mediated rapid killing of asexual liver- and blood-stage P. falciparum and blockade of gametocyte development, thereby preventing transmission, and also showed parasiticidal activity against P. berghei and P. knowlesi Hence, our data establish PfCLK3 as a target for drugs, with the potential to offer a cure-to be prophylactic and transmission blocking in malaria.
Asunto(s)
Antimaláricos/farmacología , Terapia Molecular Dirigida , Plasmodium falciparum/efectos de los fármacos , Inhibidores de Proteínas Quinasas/farmacología , Proteínas Serina-Treonina Quinasas/antagonistas & inhibidores , Proteínas Tirosina Quinasas/antagonistas & inhibidores , Proteínas Protozoarias/antagonistas & inhibidores , Animales , Antimaláricos/química , Antimaláricos/aislamiento & purificación , Antimaláricos/uso terapéutico , Gametogénesis/efectos de los fármacos , Ensayos Analíticos de Alto Rendimiento , Ratones , Ratones Endogámicos BALB C , Plasmodium falciparum/enzimología , Plasmodium falciparum/genética , Inhibidores de Proteínas Quinasas/aislamiento & purificación , Inhibidores de Proteínas Quinasas/uso terapéutico , Proteínas Serina-Treonina Quinasas/genética , Proteínas Tirosina Quinasas/genética , Proteínas Protozoarias/genética , Empalme del ARN/genética , Bibliotecas de Moléculas Pequeñas/farmacologíaRESUMEN
We describe noncovalent, reversible asparagine ethylenediamine (AsnEDA) inhibitors of the Plasmodium falciparum proteasome (Pf20S) ß5 subunit that spare all active subunits of human constitutive and immuno-proteasomes. The compounds are active against erythrocytic, sexual, and liver-stage parasites, against parasites resistant to current antimalarials, and against P. falciparum strains from patients in Africa. The ß5 inhibitors synergize with a ß2 inhibitor in vitro and in mice and with artemisinin. P. falciparum selected for resistance to an AsnEDA ß5 inhibitor surprisingly harbored a point mutation in the noncatalytic ß6 subunit. The ß6 mutant was resistant to the species-selective Pf20S ß5 inhibitor but remained sensitive to the species-nonselective ß5 inhibitors bortezomib and carfilzomib. Moreover, resistance to the Pf20S ß5 inhibitor was accompanied by increased sensitivity to a Pf20S ß2 inhibitor. Finally, the ß5 inhibitor-resistant mutant had a fitness cost that was exacerbated by irradiation. Thus, used in combination, multistage-active inhibitors of the Pf20S ß5 and ß2 subunits afford synergistic antimalarial activity with a potential to delay the emergence of resistance to artemisinins and each other.