Identification of O-Glcnacylated Proteins in Trypanosoma cruzi

Abstract

Originally an anthropozoonosis in the Americas, Chagas disease has spread from its previous borders through migration. It is caused by the protozoan Trypanosoma cruzi . Differences in disease severity have been attributed to a natural pleomorphism in T. cruzi . Several post-translational modifications (PTMs) have been studied in T. cruzi , but to date no work has focused on O-GlcNAcylation, a highly conserved monosaccharide-PTM of serine and threonine residues mainly found in nucleus, cytoplasm, and mitochondrion proteins. O-GlcNAcylation is thought to regulate protein function analogously to protein phosphorylation; indeed, crosstalk between both PTMs allows the cell to regulate its functions in response to nutrient levels and stress. Herein, we demonstrate O-GlcNAcylation in T. cruzi epimastigotes by three methods: by using specific antibodies against the modification in lysates and whole parasites, by click chemistry labeling, and by proteomics. In total, 1,271 putative O-GlcNAcylated proteins and six modification sequences were identified by mass spectrometry (data available via ProteomeXchange, ID PXD010285). Most of these proteins have structural and metabolic functions that are essential for parasite survival and evolution. Furthermore, O-GlcNAcylation pattern variations were observed by antibody detection under glucose deprivation and heat stress conditions, supporting their possible role in the adaptive response. Given the numerous biological processes in which O-GlcNAcylated proteins participate, its identification in T. cruzi proteins opens a new research field in the biology of Trypanosomatids, improve our understanding of infection processes and may allow us to identify new therapeutic targets.

MGL1 Receptor Plays a Key Role in the Control of T. cruzi Infection by Increasing Macrophage Activation through Modulation of ERK1/2, c-Jun, NF-κB and NLRP3 Pathways

“…The generation of MGL1 −/− mice allows for investigating the immunological functions of MGL1 separately from that of MGL2 at the cellular level; using these mice, it has been possible to establish that MGL1 is capable of recognize glycosylated structures expressed in parasites including protozoa and helminths [8,22]. Our previous studies, conducted in a mouse model, demonstrated that the interaction of MGL1 with highly glycosylated structures of T. cruzi (as a natural ligand) plays an essential role in immunity by increasing Mφ activation and parasite killing during in vivo T. cruzi infection [22,43]. Despite this evidence pointing to a role for MGL1 in the immune response, how MGL1 modulates the immune response against this pathogen remains unclear.…”

Characterization of adenine phosphoribosyltransferase (APRT) activity in Trypanosoma brucei brucei: Only one of the two isoforms is kinetically active

“…Along with its localization to the glycosome and expression in the procyclic life stage [40,70], a co-immunoprecipitation study identified APRT2 as a protein associated with TbTim17, the major component of the mitochondrial inner membrane translocase complex in trypanosomes, with detection of a post-translational modification (PTM), in which a methionine residue of APRT2 was fully oxidized to methionine sulfoxide (MetO) [45]. PTMs have been described in trypanosomes [71] and are a freely reversible mechanism of control at the protein level that would enable the parasites to react quickly to environmental changes, including the presumably abrupt changes associated with vector (tsetse fly) to host transmission [72]. The metabolic change in procyclic trypanosomes from glycolysis to oxidative phosphorylation due to activation of the mitochondrion [73,74] could enable reactive oxygen species (ROS) to oxidize a Met residue to MetO [75].…”

Characterization of adenine phosphoribosyltransferase (APRT) activity in Trypanosoma brucei brucei: Only one of the two isoforms is kinetically active

“…Along with its localization to the glycosome and expression in the procyclic life stage [35,62], a co-immunoprecipitation study identified APRT2 as a protein associated with TbTim17, the major component of the mitochondrial inner membrane translocase complex in trypanosomes, with detection of a post-translational modification (PTM), in which a methionine residue of APRT2 was fully oxidized to methionine sulfoxide (MetO) [40]. PTMs have been described in trypanosomes [63] and are a freely reversible mechanism of control at the protein level that would enable the parasites to react quickly to environmental changes, including the presumably abrupt changes associated with vector (tsetse fly) to host transmission [64]. The metabolic change in procyclic trypanosomes from glycolysis to oxidative phosphorylation due to activation of the mitochondrion [65,66] could enable reactive oxygen species (ROS) to oxidize a Met residue to MetO [67].…”