Dataset Information

Autocatalytic activation of a malarial egress protease is druggable and requires a protein cofactor

ABSTRACT: Malaria parasite egress from host erythrocytes (RBCs) is regulated by discharge of a parasite serine protease called SUB1 into the parasitophorous vacuole (PV). There, SUB1 activates a PV-resident cysteine protease called SERA6, enabling host RBC rupture through SERA6-mediated degradation of the RBC cytoskeleton protein beta-spectrin. Here we show that activation of Plasmodium falciparum SERA6 involves a second, autocatalytic step that is triggered by SUB1 cleavage. Unexpectedly, autoproteolytic maturation of SERA6 requires interaction in multimolecular complexes with a distinct PV-located protein cofactor, MSA180, that is itself a SUB1 substrate. Genetic ablation of MSA180 mimics SERA6 disruption, producing a fatal block in beta-spectrin cleavage and RBC rupture. Drug-like inhibitors of SERA6 autoprocessing similarly prevent beta-spectrin cleavage and egress in both P. falciparum and the emerging zoonotic pathogen P. knowlesi. Our results elucidate the egress pathway and identify SERA6 as a target for a new class of antimalarial drugs designed to prevent disease progression.

INSTRUMENT(S): Orbitrap Fusion Lumos

ORGANISM(S): Plasmodium Falciparum (isolate 3d7)

DISEASE(S): Malaria

SUBMITTER: Steven Howell

LAB HEAD: Mike Blackman

PROVIDER: PXD024084 | Pride | 2021-03-16

REPOSITORIES: Pride

ACCESS DATA

Dataset's files

Source:

			Action	DRS
	PAB7822A10RW3_SYTB2_Trypsin_BandG.msf	Msf
	PAB7822A10RW3_SYTB2_Trypsin_BandG.pdResult	Other
	PAB7822A10RW3_SYTB2_Trypsin_BandG.raw	Raw
	PAB7822A11RW3_SYTC2_Trypsin_BandI.msf	Msf
	PAB7822A11RW3_SYTC2_Trypsin_BandI.pdResult	Other

Items per page:

1 - 5 of 55

Similar Datasets

Project description:The human malaria parasite Plasmodium falciparum has a complex and multi-stage life cycle that requires extensive immune escape, invasion of human liver and blood cells, and transmission through the female Anopholes mosquito. To date, the regulatory elements orchestrating these critical parasite processes remain largely unknown. However, there is mounting evidence across a broad range of species that intergenic long non-coding RNA (lncRNA) and antisense RNA can regulate chromatin state and gene expression. To pursue such functional roles for lncRNAs in P. falciparum, we performed deep, strand-specific RNA sequencing of fifteen non-polyA-selected blood stage samples, and assembled and characterized the properties of 660 intergenic lncRNAs, 474 antisense RNAs, and 1381 circular RNAs (circRNAs). We further validated the non-canonical splice junctions of seven P. falciparum circRNAs, an emerging class of non-coding RNA with regulatory potential and unexplored functional significance in P. falciparum. Our comprehensive analysis of P. falciparum lncRNAs indicates a functional role for these transcripts; P. falciparum intergenic lncRNAs and antisense RNAs are developmentally regulated in a similar periodic fashion to annotated transcripts, and sense-antisense pair expression is significantly anti-correlated. Notable outliers include intergenic lncRNAs that strongly peak in expression during parasite invasion, such as the telomere-associated lncRNA-TARE family, antisense transcripts that drop in expression during parasite invasion, and a highly correlated, multi-exonic, antisense counterpart to P. falciparum Gametocyte Developmental Protein 1 (PfGDV1). Taken together, our results present over two thousand P. falciparum intergenic lncRNA, antisense, and circRNA candidates and highlight promising P. falciparum lncRNAs for future investigation. We harvested fifteen blood stage samples from two biological replicate time-courses. The first time-course comprised of eleven samples that finely map temporal changes during P. falciparum blood stage development. We harvested samples over 56 hours, at roughly 4-hour time intervals, from a tightly synchronized P. falciparum 3D7 parasite population. As the asexual blood stage is an approximately 48-hour cycle, this time-course allowed us to profile gene expression during RBC rupture and parasite invasion. The second time-course comprised of four samples harvested in synchronous P. falciparum 3D7 parasites approximately four hours before and after the ring to trophozoite and trophozoite to schizont morphological stage transitions, which occur during the blood stage at 24 hours post invasion (hpi) and 36 hpi, respectively.

Project description:Hereditary elliptocytosis is a red blood cell (RBC) disease mainly caused by mutations in spectrin, leading to cytoskeletal destabilization. Although patients with heterozygous mutation in α-spectrin (SPTA1) are asymptomatic, morphological changes and hemolysis are observed upon reduced functional α-spectrin production. The molecular mechanism is unknown. We analyzed the consequences of a α-spectrin mutation in a patient almost exclusively expressing the Pro260 variant of SPTA1 (pEl). pEl RBCs showed decreased size and circularity and increased fragility. The pEl RBC proteome was globally preserved but spectrin density at the cell edges rised and the two membrane anchorage complexes were less segregated. Hence, the pEl membrane was strongly impaired. First, the lipidome was modified, showing decreased phosphatidylserine vs increased lysophosphatidylserine species. Second, although membrane transversal asymmetry was preserved, curvature at the RBC edges and rigidity were increased. Third, sphingomyelin-enriched domains were altered in abundance, membrane:cytoskeleton anchorage and cholesterol content were targeted by the plasmatic acid sphingomyelinase (aSMase). Fourth, membrane calcium exchanges through the mechanosensitive channel PIEZO1 and the efflux pump PMCA were impaired, leading to increased intracellular calcium and ROS, lipid peroxidation and methemoglobin. Mecanistically, increased curvature through lysophosphatidylserine membrane insertion in healthy RBCs abrogated calcium influx. Cholesterol depletion of sphingomyelin-enriched domains by methyl-beta-cyclodextrin in pEl RBCs worsened calcium accumulation whereas aSMase inhibition by amitriptyline did the opposite. Those data indicated that α-spectrin tetramerization defect, lysophosphatidylserine, cholesterol domain depletion and aSMase cooperate to alter membrane properties and calcium exchanges, leading to calcium accumulation and oxidative stress. It could help develop novel therapies

Dataset Information

Autocatalytic activation of a malarial egress protease is druggable and requires a protein cofactor

Dataset's files

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets