Unique behavior of Trypanosoma cruzi mevalonate kinase: A conserved glycosomal enzyme involved in host cell invasion and signaling

Abstract

Mevalonate kinase (MVK) is an essential enzyme acting in early steps of sterol isoprenoids biosynthesis, such as cholesterol in humans or ergosterol in trypanosomatids. MVK is conserved from bacteria to mammals, and localizes to glycosomes in trypanosomatids. During the course of T. cruzi MVK characterization, we found that, in addition to glycosomes, this enzyme may be secreted and modulate cell invasion. To evaluate the role of TcMVK in parasite-host cell interactions, TcMVK recombinant protein was produced and anti-TcMVK antibodies were raised in mice. TcMVK protein was detected in the supernatant of cultures of metacyclic trypomastigotes (MTs) and extracellular amastigotes (EAs) by Western blot analysis, confirming its secretion into extracellular medium. Recombinant TcMVK bound in a non-saturable dose-dependent manner to HeLa cells and positively modulated internalization of T. cruzi EAs but inhibited invasion by MTs. In HeLa cells, TcMVK induced phosphorylation of MAPK pathway components and proteins related to actin cytoskeleton modifications. We hypothesized that TcMVK is a bifunctional enzyme that in addition to playing a classical role in isoprenoid synthesis in glycosomes, it is secreted and may modulate host cell signaling required for T. cruzi invasion.

AFAP-1L1-mediated actin filaments crosslinks hinder Trypanosoma cruzi cell invasion and intracellular multiplication

“…It is reasonable to speculate that AFAP-1L1 shRNA treated cells Cortez et al, 2006;Ferreira et al, 2006;Rodrigues et al, 2012;Ferreira et al, 2016).…”

Commentary: Systems Biology Approach to Model the Life Cycle of Trypanosoma cruzi

“…Examples of these parasite's moonlighting enzymes include: a hexokinase in Leishmania donovani , which functions as a hemoglobin receptor within the parasite's flagellar pocket; the glycolytic enzyme aldolase in Toxoplasma gondii and Plasmodium falciparum , which has an additional (even if non-essential) function in host-cell invasion; various soluble metabolic enzymes in Trichomonas vaginalis , which moonlight as adhesins allowing parasite-host cell adhesion; the mitochondrial peroxiredoxin in Leishmania infantum , which not only functions as a peroxidase, but also as a chaperone essential for pathogenesis; the α-ketoglutarate dehydrogenase E2 in bloodstream Trypanosoma brucei , which moonlights in the mitochondria ensuring a correct kinetoplast DNA inheritance (Collingridge et al, 2010; Ginger, 2014). Recently, Ferreira and colleagues have shown that the enzyme mevalonate kinase, originally involved in sterol isoprenoids biosynthesis in T. cruzi 's glycosomes, is also secreted and may modulate host cell signaling during parasite invasion (Ferreira et al, 2016). …”

Trypanocidal and leishmanicidal activity of six limonoids

“…The intra-macrophages amastigote assay was performed as previously described with some modification [20]. In brief,…”