Plasmodium falciparum histidine triad protein and calmodulin modulates calcium homeostasis and intracellular proteolysis

Smaul, Mayrim Machado Gomes; Budu, Alexandre; Montagna, Georgina N.; Ferrara, Taíse Fernanda da Silva; Maluf, Sarah El Chamy; Bagnaresi, Piero; Machado, Marcelo Marcondes Ferreira; Santos, Fellipe Bronze dos; Azevedo, Mauro Ferreira de; Carmona, Adriana K.; Gazarini, Marcos L.

doi:10.1016/j.bbrc.2018.06.067

Cited by 3 publications

(2 citation statements)

References 20 publications

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“…The mitochondrion [18], the parasitophorous vacuole [19], and the endoplasmic reticulum [20] also participate in the homeostasis of this important second messenger. An important downstream effect of calcium signaling in Plasmodium is the modulation of proteolytic activity related to cysteine proteases [21][22][23][24]. Although the Plasmodium aminopeptidases occur in cell compartments with calcium fluctuations, a direct correlation with these enzymes' activity is uncertain.…”

Section: Introductionmentioning

confidence: 99%

Overexpression of Plasmodium falciparum M1 Aminopeptidase Promotes an Increase in Intracellular Proteolysis and Modifies the Asexual Erythrocytic Cycle Development

et al. 2021

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Plasmodium falciparum, the most virulent of the human malaria parasite, is responsible for high mortality rates worldwide. We studied the M1 alanyl-aminopeptidase of this protozoan (PfA-M1), which is involved in the final stages of hemoglobin cleavage, an essential process for parasite survival. Aiming to help in the rational development of drugs against this target, we developed a new strain of P. falciparum overexpressing PfA-M1 without the signal peptide (overPfA-M1). The overPfA-M1 parasites showed a 2.5-fold increase in proteolytic activity toward the fluorogenic substrate alanyl-7-amido-4-methylcoumarin, in relation to the wild-type group. Inhibition studies showed that overPfA-M1 presented a lower sensitivity against the metalloaminopeptidase inhibitor bestatin and to other recombinant PfA-M1 inhibitors, in comparison with the wild-type strain, indicating that PfA-M1 is a target for the in vitro antimalarial activity of these compounds. Moreover, overPfA-M1 parasites present a decreased in vitro growth, showing a reduced number of merozoites per schizont, and also a decrease in the iRBC area occupied by the parasite in trophozoite and schizont forms when compared to the controls. Interestingly, the transgenic parasite displays an increase in the aminopeptidase activity toward Met-, Ala-, Leu- and Arg-7-amido-4-methylcoumarin. We also investigated the potential role of calmodulin and cysteine proteases in PfA-M1 activity. Taken together, our data show that the overexpression of PfA-M1 in the parasite cytosol can be a suitable tool for the screening of antimalarials in specific high-throughput assays and may be used for the identification of intracellular molecular partners that modulate their activity in P. falciparum.

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Section: Introductionmentioning

confidence: 99%

Overexpression of Plasmodium falciparum M1 Aminopeptidase Promotes an Increase in Intracellular Proteolysis and Modifies the Asexual Erythrocytic Cycle Development

et al. 2021

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“…falciparum genome encodes various calmodulin-containing proteins that play crucial role in parasite growth and proliferation via cytosolic Ca 2+ fluctuation (Budu, Gomes et al 2016, Gomes Smaul, Budu et al 2018. It might possible that melatonin interaction to either cytosolic proteins or nuclear receptor is the key trigger to [Ca 2+ ]cyt release as well as different parasite form distribution.…”

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Dissecando o mecanismo de sinalização intracelular de cálcio e a caracterização do gene Pf1468 no parasita da malária humana >i<P. falciparum>/i<

Singh¹

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A sinalização intracelular do cálcio é fundamental para o crescimento do parasita da malária humana P. falciparum e para a transmissão da doença. A presença de distintas organelas para armazenamento de cálcio indica a coordenação mútua para a homeostase do íon durante o crescimento do parasita. O aumento do cálcio citosólico durante o ciclo assexuado regula muitos eventos downstream, especialmente a saída e a invasão do parasita. No entanto, nosso entendimento atual é limitado aos eventos upstream relacionados a flutuações de cálcio e aos eventos que iniciam as cascatas de sinalização durante a saída ou invasão do parasita. Já foram descobertas proteínas semelhantes a GPCRs no genoma do P. falciparum, mas a caracterização funcional ainda estava faltando. No presente estudo, demonstramos que o P. falciparum percebe a mudança extracelular de K + no microambiente por uma das proteínas semelhantes a GPCR, PfSR25, e desencadeia o aumento do cálcio citosólico. Parasitas knockout PfSR25 foram incapazes de responder a mudança na concentração de K + , sugerindo fortemente que PfSR25 seja um sensor de potássio. Em estudo paralelo, descobrimos que o efluxo de cálcio citosólico no parasita também é atribuído ao vacúolo alimentar. O PfCRT, um transportador presente na membrana do vacúolo alimentar, é fundamental no efluxo de cálcio e a mutação nesta proteína que levam à resistência a cloroquina em parasitas também afeta o efluxo de cálcio citosólico. Por outro lado, investigamos e caracterizamos uma nova proteína em P. falciparum, PfMel, que é modulada por melatonina. A marcação de PfMel com sonda de proteína fluorescente indicou a sua localização nuclear no ciclo parasitário intraeritrocítico. Nós descobrimos que o knocking down condicional de PfMel levou a incapacidade dos parasitas de sicronizar em cultura na presença da melatonina. Simultaneamente, os parasitas que expressam menos PfMel têm redução significativa no efluxo intracelular de Ca 2+ induzido pela melatonina.

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Comparative analysis of excretory–secretory products of muscle larvae of three isolates of Trichinella pseudospiralis by the iTRAQ method

Wang

Bai

Tang

et al. 2021

Veterinary Parasitology

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Plasmodium falciparum histidine triad protein and calmodulin modulates calcium homeostasis and intracellular proteolysis

Cited by 3 publications

References 20 publications

Overexpression of Plasmodium falciparum M1 Aminopeptidase Promotes an Increase in Intracellular Proteolysis and Modifies the Asexual Erythrocytic Cycle Development

Overexpression of Plasmodium falciparum M1 Aminopeptidase Promotes an Increase in Intracellular Proteolysis and Modifies the Asexual Erythrocytic Cycle Development

Dissecando o mecanismo de sinalização intracelular de cálcio e a caracterização do gene Pf1468 no parasita da malária humana >i<P. falciparum>/i<

Comparative analysis of excretory–secretory products of muscle larvae of three isolates of Trichinella pseudospiralis by the iTRAQ method

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