UGO is a multipass membrane protein that is key to sense and transduce cues for schizont egress and gametocyte activation in malaria parasites
Ontology highlight
ABSTRACT:
INSTRUMENT(S): Orbitrap Fusion Lumos
ORGANISM(S): Plasmodium Berghei Anka
TISSUE(S): Gametocyte
SUBMITTER: 
alexandre Hainard
LAB HEAD: Mathieu Brochet
PROVIDER: PXD035569 | Pride | 2023-04-28
REPOSITORIES: Pride
Similar Datasets
Project description:In malaria parasites, cGMP signalling is mediated by a single cGMP-dependent protein kinase (PKG) . One of the major functions of PKG is to control calcium signals essential for the parasite to exit red blood cells or for the transmission of the gametocyte stages to the mosquito . However, how PKG controls these signals in the absence of known second messenger-dependent calcium channels or scaffolding proteins remains a mystery. Here we use pull-down approaches to identify a PKG partner protein in both Plasmodium falciparum schizonts and P. berghei gametocytes. This partner, named ICM1, is a polytopic membrane protein with homologies to transporters and calcium channels, raising the possibility of a direct functional link between PKG and calcium homeostasis. Phosphoproteomic analyses in both Plasmodium species highlight a densely phosphorylated region of ICM1 with multiple phosphorylation events dependent on PKG activity. Conditional disruption of the P. falciparum ICM1 gene results in reduced cGMP-dependent calcium mobilisation associated with defective egress and invasion. Stage-specific depletion of ICM1 in P. berghei gametocytes blocks gametogenesis due to the inability of mutant parasites to mobilise intracellular calcium upon PKG activation. These results provide us with new insights into the atypical calcium homeostasis in malaria parasites.
2021-01-25 | PXD020210 | Pride
Project description:In malaria parasites, cGMP signalling is mediated by a single cGMP-dependent protein kinase (PKG). One of the major functions of PKG is to control calcium signals essential for the parasite to exit red blood cells or for the transmission of the gametocyte stages to the mosquito. However, how PKG controls these signals in the absence of known second messenger-dependent calcium channels or scaffolding proteins remains a mystery. Here we use pull-down approaches to identify a PKG partner protein in both Plasmodium falciparum schizonts and P. berghei gametocytes. This partner, named ICM1, is a polytopic membrane protein with homologies to transporters and calcium channels, raising the possibility of a direct functional link between PKG and calcium homeostasis. Phosphoproteomic analyses in both Plasmodium species highlight a densely phosphorylated region of ICM1 with multiple phosphorylation events dependent on PKG activity. Conditional disruption of the P. falciparum ICM1 gene results in reduced cGMP-dependent calcium mobilisation associated with defective egress and invasion. Stage-specific depletion of ICM1 in P. berghei gametocytes blocks gametogenesis due to the inability of mutant parasites to mobilise intracellular calcium upon PKG activation. These results provide us with new insights into the atypical calcium homeostasis in malaria parasites
2021-01-25 | PXD020189 | Pride
Project description:In malaria parasites, all cGMP-dependent signalling is mediated through a single cGMP-dependent protein kinase (PKG). A major function of PKG is to control calcium signals essential for the parasite to exit red blood cells or for transmission to the mosquito vector. However, how PKG controls these signals in the absence of known second messenger-dependent calcium channels or scaffolding proteins remains a mystery. Here we identify a tightly-associated PKG partner protein in both Plasmodium falciparum asexual blood stages and P. berghei gametocytes. Named ICM1, the partner is a polytopic membrane protein with homology to transporters and calcium channels, raising the possibility of a direct functional link between PKG and calcium homeostasis. Phosphoproteomic analyses in both Plasmodium species highlight a densely phosphorylated region of ICM1 with multiple phosphorylation events dependent upon PKG activity. Stage-specific depletion of ICM1 in P. berghei blocks gametogenesis due to the inability of mutant parasites to mobilise intracellular calcium upon PKG activation, whilst conditional disruption of P. falciparum ICM1 results in reduced cGMP-dependent calcium mobilisation associated with defective egress and invasion. Our findings provide new insights into the atypical calcium homeostasis in malaria parasites essential for pathology and disease transmission.
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Project description:Plasmodium, the malaria parasite, undergoes a complex life cycle, which alternates between a vertebrate host and a mosquito vector of the genus Anopheles. In red blood cells of the vertebrate host, Plasmodium multiplies asexually or differentiates into gamete precursors, the male and female gametocytes, responsible for parasite transmission. Sexual stage maturation occurs in the midgut of the mosquito vector, where male and female gametes egress from the host erythrocyte to form a zygote. Gamete egress entails the successive rupture of two membranes surrounding the parasite, the parasitophorous vacuole membrane and the erythrocyte plasma membrane.
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Project description:During intra-erythrocytic development, late asexually replicating Plasmodium falciparum parasites sequester from peripheral circulation. This facilitates chronic infection and is linked to severe disease and organ-specific pathology including cerebral and placental malaria. Immature gametocytes M-bM-^@M-^S sexual stage precursor cells M-bM-^@M-^S likewise disappear from circulation. Recent work has demonstrated that these sexual stage parasites are located in the hematopoietic system of the bone marrow before mature gametocytes are released into the blood stream to facilitate mosquito transmission. However, as sequestration occurs only in vivo and not during in vitro culture, the mechanisms by which it is regulated and enacted (particularly by the gametocyte stage) remain poorly understood. We generated the most comprehensive P. falciparum functional gene network to date by integrating global transcriptional data from a large set of asexual and sexual in vitro samples, patient-derived in vivo samples, and a new set of in vitro samples profiling sexual commitment. We defined more than 250 functional modules (clusters) of genes that are co-expressed primarily during the intra-erythrocytic parasite cycle, including 35 during sexual commitment and gametocyte development. Comparing the in vivo and in vitro datasets allowed us, for the first time, to map the time point of asexual parasite sequestration in patients to 22 hours post invasion, confirming previous in vitro observations on the dynamics of host cell modification and cytoadherence. Moreover, we were able to define the properties of gametocyte sequestration, demonstrating the presence of two circulating gametocyte populations: gametocyte rings between 0 and ~30 hours post invasion and mature gametocytes after around 7 days post invasion. We used 164/TdTom, a transgenic parasite line expressing a red fluorescent protein reporter under a gametocyte-specific promoter to generate schizont samples. Schizonts were subsequently isolated from both the fluorescent and non-fluorescent population by FACS and prepared for microarray analysis. Two biological replicates were produced for both the fluorescent and the non-fluorescent samples.
2015-01-13 | E-GEOD-64887 | biostudies-arrayexpress
Project description:Transmission of malaria parasites to the mosquito is mediated by sexual precursor cells, the gametocytes. Upon entering the mosquito midgut, the gametocytes egress from the enveloping erythrocyte while passing through gametogenesis. Egress follows an inside-out mode during which the membrane of the parasitophorous vacuole ruptures prior to the erythrocyte membrane. Membrane rupture requires the exocytosis of specialized secretory vesicles of the parasites; i.e. the osmiophilic bodies (OBs) involved in rupture of the parasitophorous vacuole membrane, and vesicles (here termed g-exonemes) that harbour the perforin-like protein PPLP2 needed for erythrocyte lysis. While several OB proteins are known, like G377 and MDV1/Peg3, the protein composition of the g-exonemes remains unclear. Here, we used high-resolution imaging and BioID methods to study the two types of egress vesicles in Plasmodium falciparum gametocytes. We show that OB exocytosis precedes discharge of the g-exonemes and that exocytosis of the g-exonemes, but not of the OBs, is calcium-sensitive. Further, the two types of vesicles exhibit distinct proteomes. In addition to known egress-related proteins, our analyses revealed novel markers of OBs and g-exonemes, including proteins involved in vesicle trafficking. Our data provide insight into the immense molecular machinery required for the inside-out egress of P. falciparum gametocytes.
2024-01-25 | PXD039679 | JPOST Repository
Project description:Purpose: In malaria parasites, the regulation of mRNA translation, storage and degradation is a critical aspect of gene expression, especially during the life stage transition. Since the DEAD-box helicases are involved in RNA metabolism, we wanted to determine whether pfdozi disruption led to altered mRNA abundance in P. falciparum. Methods: In this study, we functionally characterized the DEAD-box RNA helicase PfDOZI in the human malaria parasite Plasmodium falciparum and discovered its functions on mRNA metabolism during development. We generate a pfdozi gene knockout (KO) parasite line. 1). The transcriptomic analysis via RNAseq to the asexual parasites at four stages (ring, early trophozoite, late trophozoite, and schizont)(10h, 20h, 30h, and 40h post-invasion) and the sexual stage (gametocytes) between KO and wildtype (WT) 3D7 parasite line were performed in triplicate. Total RNA was isolated from the purified parasites using the Quick-RNA MiniPrep kit (Zymo Research). RNA sequencing libraries were prepared using the KAPA stranded RNA-seq library preparation kit (Roche) with 500 ng RNA from each sample. Illumina adapter sequence removal and quality trimming of reads were performed using Trimmomatic. Only reads that had a minimum length of 50 base pairs were retained. Reads were then mapped to the P. falciparum 3D7 strain reference genome with HISAT2. Differentially expressed genes are determined by DESeq2 with Padj < 0.01 and absolute log2 fold change higher than 1. 2). To investigate the function of pfdozi in stress response, both KO and WT parasites at the schizont stage were cultured under stress conditions. RNAs were harvested for the transcriptomic analysis via RNAseq. 3). To identify the mRNA targets of PfDOZI in schizonts and gametocytes, we performed RNA-immunoprecipitation (RIP) coupled with next-generation sequencing from the PfDOZI::GFP parasites. A gaussian mixture model with a set of stringent criteria, including a read-depth coverage greater than 10, a fold enrichment ratio greater than 2, and posterior probabilities higher than 0.95 in both replicates. Results: 1). RNA-seq analysis identified up-regulation of 18, 4, 7 and 130 genes and down-regulation of 104, 44, 28 and 15 genes in the Δpfdozi parasite compared to WT 3D7 (fold change ≥ 2 and adjusted P (Padj) < 0.01) at ring (10h), early trophozoite (20h), late trophozoite (30h) and schizont (40h) stage, respectively. Our results showed that pfdozi disruption led to the upregulation of invasion-related genes in schizonts; 2). RNA-seq analysis revealed that the effect of pfdozi disruption on gametocytes was substantially more profound than in asexual stages, with 842 downregulated and 752 upregulated transcripts (fold change ≥2, Padj < 0.01) in the Δpfdozi gametocyte. About 80% of these markedly reduced transcripts are gametocyte/ookinete-specific transcripts. Genes related to microtubule/cytoskeleton, cellular respiration, and crystalloid were significantly enriched among the downregulated genes, which agrees with the defective morphogenesis of the Δpfdozi gametocytes. 3). RNAseq analysis showed that under the stress conditions, the WT parasites showed three-fold more upregulated transcripts (591) than downregulated (149), suggesting that significantly more transcripts were protected from degradation under stress conditions. In contrast, the Δpfdozi parasites had a much higher proportion (57%, 463) of downregulated than that of upregulated transcripts (43%, 346) under such stress conditions. 4). The RIP-seq analysis collectively identified the potential target mRNAs of the PfDOZI complex(es) in P. falciparum schizonts and gametocytes, identified 823 and 1377 transcripts as potential target mRNAs of the PfDOZI complexes in schizonts and gametocytes, respectively. Our data also showed significant overlaps with genes whose expression was disturbed upon pfdozi disruption. Conclusions: Collectively, we have demonstrated that PfDOZI, likes its metazoan orthologs, is a versatile regulator of mRNA metabolism, and these functions are dynamically regulated during development with stage-specific characteristics.
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Project description:To determine the role of ALBA4 in mRNA homeostasis in Plasmodium parasites, we performed comparative total RNA-seq between a WT-GFP line and an alba4-null line. We performed these experiments at three points in the life cycle - asexual (schizont), sexual (gametocyte), and oocyst sporozoite stages. We found that ALBA4 has a multi-faceted role in mRNA homeostasis, and is involved in mRNA fate determination. ALBA4 appears to act in a stage-specific manner, affecting different sets of transcripts in each stage. Our data suggests that ALBA4 plays opposing roles - possibly promoting degradation in schizonts, while promoting mRNA protection in gametocytes. In oocyst sporozoites, it appears that ALBA4 has a mixed role, and may be involved in both degradation and protection of mRNAs.
2017-08-25 | GSE81834 | GEO
Project description:Transmission of the malaria parasite Plasmodium falciparum from the human to the mosquito is mediated by the intraerythrocytic gametocytes, which, once taken up during a blood meal, become activated to initiate sexual reproduction. Because gametocytes are the only parasite stages able to establish an infection in the mosquito, they are crucial for spreading the tropical disease. During gametocyte maturation, different repertoires of genes are switched on and off in a well-coordinated sequence, pointing to regulatory mechanisms of gene expression. While epigenetic gene control has been studied during erythrocytic schizogony of P. falciparum, little is known about this process during parasite human-to-mosquito transmission of the parasite. To unveil the potential role of histone acetylation during gene expression in gametocytes, we carried out a microarray-based transcriptome analysis on gametocytes treated with the histone deacetylase inhibitor trichostatin A (TSA).
2017-05-24 | GSE99223 | GEO
Project description:In order to assess what PyNOT1-G contributes to Plasmodium gametocyte commitment and maturation, we conducted comparative RNA-seq on enriched schizonts and gametocytes. We identified many transcripts that are dysregulated in accordance with the gene deletion phenotype.
2021-05-24 | GSE136674 | GEO