scholarly journals The Plasmodium falciparum protein VCAP1 controls Maurer’s cleft morphology, knob architecture and PfEMP1 trafficking

2019 ◽  
Author(s):  
Emma McHugh ◽  
Olivia Carmo ◽  
Adam Blanch ◽  
Oliver Looker ◽  
Boyin Liu ◽  
...  
Keyword(s):  
Plasmodium Falciparum ◽  
Protein Interaction ◽  
Protein Trafficking ◽  
Placental Malaria ◽  
Protein Composition ◽  
Surface Expression ◽  
Virulence Protein ◽  
Infected Rbcs ◽  
Loading And Unloading ◽  
Maurer's Clefts

AbstractThe malaria parasite, Plasmodium falciparum, traffics the virulence protein, P. falciparum erythrocyte membrane protein 1 (PfEMP1) to the surface of infected red blood cells (RBCs) via membranous organelles, known as the Maurer’s clefts. We developed a method for efficient enrichment of Maurer’s clefts and profiled the protein composition of this trafficking organelle. We identified 13 previously uncharacterised or poorly characterised Maurer’s cleft proteins. We generated transfectants expressing GFP-fusions of 7 proteins and confirmed their Maurer’s cleft location. Using co-immunoprecipitation and mass spectrometry we have generated a protein interaction map of proteins at the Maurer’s clefts. We identified two key clusters that may function in the loading and unloading of PfEMP1 into and out of the Maurer’s clefts. We focus on a putative PfEMP1 loading complex that includes the newly characterised virulence complex assembly protein 1 (VCAP1). Disruption of VCAP1 causes Maurer’s cleft fragmentation, aberrant knobs, ablation of PfEMP1 surface expression and loss of the PfEMP1 directed adhesion. ΔVCAP1 parasite lines have a growth advantage compared to wildtype parasites; and the infected RBCs are more deformable and more osmotically fragile.ImportanceThe trafficking of the virulence antigen PfEMP1 and its presentation at the knob structures at the surface of parasite infected RBCs is central to severe adhesion related pathologies such as cerebral and placental malaria. This work adds to our understanding of how PfEMP1 is trafficked to the RBC membrane by defining the protein-protein interaction networks that function at the Maurer’s clefts controlling PfEMP1 loading and unloading. This work adds significantly to our understanding of virulence protein trafficking and will provide crucial knowledge that will be required to determine the mechanisms underpinning parasite driven host cell remodelling, parasite survival within the host and virulence mechanisms.

scholarly journals Role of Plasmodium falciparum Protein GEXP07 in Maurer’s Cleft Morphology, Knob Architecture, and P. falciparum EMP1 Trafficking

mBio ◽  
2020 ◽  
Vol 11 (2) ◽  
Author(s):  
Emma McHugh ◽  
Olivia M. S. Carmo ◽  
Adam Blanch ◽  
Oliver Looker ◽  
Boyin Liu ◽  
...  
Keyword(s):  
Plasmodium Falciparum ◽  
Fluorescent Protein ◽  
Placental Malaria ◽  
Protein Composition ◽  
Surface Expression ◽  
Content Type ◽  
Virulence Protein ◽  
Infected Rbcs ◽  
Loading And Unloading ◽  
Maurer's Clefts

ABSTRACT The malaria parasite Plasmodium falciparum traffics the virulence protein P. falciparum erythrocyte membrane protein 1 (PfEMP1) to the surface of infected red blood cells (RBCs) via membranous organelles, known as the Maurer’s clefts. We developed a method for efficient enrichment of Maurer’s clefts and profiled the protein composition of this trafficking organelle. We identified 13 previously uncharacterized or poorly characterized Maurer’s cleft proteins. We generated transfectants expressing green fluorescent protein (GFP) fusions of 7 proteins and confirmed their Maurer’s cleft location. Using co-immunoprecipitation and mass spectrometry, we generated an interaction map of proteins at the Maurer’s clefts. We identified two key clusters that may function in the loading and unloading of PfEMP1 into and out of the Maurer’s clefts. We focus on a putative PfEMP1 loading complex that includes the protein GEXP07/CX3CL1-binding protein 2 (CBP2). Disruption of GEXP07 causes Maurer’s cleft fragmentation, aberrant knobs, ablation of PfEMP1 surface expression, and loss of the PfEMP1-mediated adhesion. ΔGEXP07 parasites have a growth advantage compared to wild-type parasites, and the infected RBCs are more deformable and more osmotically fragile. IMPORTANCE The trafficking of the virulence antigen PfEMP1 and its presentation at the knob structures at the surface of parasite-infected RBCs are central to severe adhesion-related pathologies such as cerebral and placental malaria. This work adds to our understanding of how PfEMP1 is trafficked to the RBC membrane by defining the protein-protein interaction networks that function at the Maurer’s clefts controlling PfEMP1 loading and unloading. We characterize a protein needed for virulence protein trafficking and provide new insights into the mechanisms for host cell remodeling, parasite survival within the host, and virulence.

scholarly journals Virulence determinant, PTP7, controls vesicle budding from the Maurer’s clefts, adhesin protein trafficking and host cell remodeling in Plasmodium falciparum

2021 ◽  
Author(s):  
Olivia M. S. Carmo ◽  
Gerald J Shami ◽  
Dezerae Cox ◽  
Boyin Liu ◽  
Adam J Blanch ◽  
...  
Keyword(s):  
Plasmodium Falciparum ◽  
Cell Surface ◽  
Blood Cell ◽  
Red Blood Cell ◽  
Protein Trafficking ◽  
Low Complexity ◽  
Vesicle Budding ◽  
Cell Remodeling ◽  
Virulence Protein ◽  
Maurer's Clefts

Presentation of the variant antigen, Plasmodium falciparum erythrocyte membrane protein 1 (EMP1), at knob-like protrusions on the surface of infected red blood cells, underpins P. falciparum malaria pathogenicity. Here we describe a protein PF3D7_0301700 (PTP7), that functions at the nexus between the intermediate trafficking organelle, the Maurer’s cleft, and the red blood cell surface. Genetic disruption of PTP7 leads to accumulation of vesicles at the Maurer’s clefts, grossly aberrant knob morphology, and failure to deliver EMP1 to the red blood cell surface.  We show that an expanded low complexity sequence in the C-terminal region of PTP7, found only in the Laverania clade of Plasmodium , is critical for efficient virulence protein trafficking.

scholarly journals Maurer's clefts of Plasmodium falciparum are secretory organelles that concentrate virulence protein reporters for delivery to the host erythrocyte

Blood ◽  
2008 ◽  
Vol 111 (4) ◽  
pp. 2418-2426 ◽  
Author(s):  
Souvik Bhattacharjee ◽  
Christiaan van Ooij ◽  
Bharath Balu ◽  
John H. Adams ◽  
Kasturi Haldar
Keyword(s):  
Plasmodium Falciparum ◽  
Protein Trafficking ◽  
Parasite Protein ◽  
Human Malaria Parasite ◽  
Parasite Plasmodium ◽  
Virulence Protein ◽  
Parasite Plasmodium Falciparum ◽  
Blood Stage Infection ◽  
Maurer's Clefts ◽  
Stage Infection

In blood-stage infection by the human malaria parasite Plasmodium falciparum, export of proteins from the intracellular parasite to the erythrocyte is key to virulence. This export is mediated by a host-targeting (HT) signal present on a “secretome” of hundreds of parasite proteins engaged in remodeling the erythrocyte. However, the route of HT-mediated export is poorly understood. Here we show that minimal soluble and membrane protein reporters that contain the HT motif and mimic export of endogenous P falciparum proteins are detected in the lumen of “cleft” structures synthesized by the pathogen. Clefts are efficiently targeted by the HT signal. Furthermore, the HT signal does not directly translocate across the parasitophorous vacuolar membrane (PVM) surrounding the parasite to deliver protein to the erythrocyte cytoplasm, as suggested by current models of parasite protein trafficking to the erythrocyte. Rather, it is a lumenal signal that sorts protein into clefts, which then are exported beyond the PVM. These data suggest that Maurer's clefts, which are unique to the virulent P falciparum species, are pathogen-induced secretory organelles that concentrate HT-containing soluble and membrane parasite proteins in their lumen for delivery to the host erythrocyte.

A network-based approach reveals novel invasion and Maurer's clefts-related proteins in Plasmodium falciparum

2019 ◽  
Vol 15 (6) ◽  
pp. 431-441 ◽  
Author(s):  
Dibyajyoti Das ◽  
Sowmya Ramaswamy Krishnan ◽  
Arijit Roy ◽  
Gopalakrishnan Bulusu
Keyword(s):  
Plasmodium Falciparum ◽  
Protein Interaction ◽  
Protein Interaction Network ◽  
Interaction Network ◽  
Disease Pathogenesis ◽  
Protein Protein Interaction ◽  
Novel Proteins ◽  
Maurer's Clefts ◽  
Related Proteins ◽  
Protein Protein Interaction Network

To understand disease pathogenesis, all the disease-related proteins must be identified. In this work, known proteins were used to identify related novel proteins using RWR method on a dynamic P. falciparum protein–protein interaction network.

scholarly journals Trafficking and Association of Plasmodium falciparum MC-2TM with the Maurer’s Clefts

Pathogens ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 431
Author(s):  
Raghavendra Yadavalli ◽  
John W. Peterson ◽  
Judith A. Drazba ◽  
Tobili Y. Sam-Yellowe
Keyword(s):  
Plasmodium Falciparum ◽  
Erythrocyte Membrane ◽  
Sodium Carbonate ◽  
Infected Erythrocyte ◽  
Brefeldin A ◽  
Specific Expression ◽  
Lipid Interactions ◽  
And Topology ◽  
Streptolysin O ◽  
Maurer's Clefts

In this study, we investigated stage specific expression, trafficking, solubility and topology of endogenous PfMC-2TM in P. falciparum (3D7) infected erythrocytes. Following Brefeldin A (BFA) treatment of parasites, PfMC-2TM traffic was evaluated using immunofluorescence with antibodies reactive with PfMC-2TM. PfMC-2TM is sensitive to BFA treatment and permeabilization of infected erythrocytes with streptolysin O (SLO) and saponin, showed that the N and C-termini of PfMC-2TM are exposed to the erythrocyte cytoplasm with the central portion of the protein protected in the MC membranes. PfMC-2TM was expressed as early as 4 h post invasion (hpi), was tightly colocalized with REX-1 and trafficked to the erythrocyte membrane without a change in solubility. PfMC-2TM associated with the MC and infected erythrocyte membrane and was resistant to extraction with alkaline sodium carbonate, suggestive of protein-lipid interactions with membranes of the MC and erythrocyte. PfMC-2TM is an additional marker of the nascent MCs.

scholarly journals A distinct 5' flanking var gene region regulates Plasmodium falciparum variant erythrocyte surface antigen expression in placental malaria

2002 ◽  
Vol 45 (1) ◽  
pp. 155-167 ◽  
Author(s):  
Aleida Vazquez-Macias ◽  
Perla Martinez-Cruz ◽  
Maria Cristina Castaneda-Patlan ◽  
Christine Scheidig ◽  
Jurg Gysin ◽  
...  
Keyword(s):  
Plasmodium Falciparum ◽  
Surface Antigen ◽  
Placental Malaria ◽  
Antigen Expression ◽  
Gene Region ◽  
Erythrocyte Surface ◽  
Surface Antigen Expression ◽  
Var Gene

Abstract 393: Reticulon-4B Protects Against Endoplasmic Reticulum Stress Induced Platelet Apoptosis and Hyperactivation in Diabetes

2015 ◽  
Vol 35 (suppl_1) ◽  
Author(s):  
Yan Wang ◽  
Wai Ho Tang ◽  
Xinbo Zhang ◽  
Jing Du ◽  
John Hwa ◽  
...  
Keyword(s):  
Diabetes Mellitus ◽  
Endoplasmic Reticulum ◽  
Er Stress ◽  
Protein Trafficking ◽  
Surface Expression ◽  
Diabetic Mouse ◽  
Mitochondrial Damage ◽  
Ros Production ◽  
Mitochondria Membrane Potential ◽  
Platelet Apoptosis

Background: Hyperglycemia triggered endoplasmic reticulum (ER) stress is one of the major causes for platelet hyperactivation and apoptosis in diabetes mellitus (DM). Reticulon-4B (aka Nogo-B) mainly localizes to the ER, and has been shown to influence the ER morphology, ER-Golgi trafficking, apoptotic balance, vesicle formation and protein trafficking in cells. The present study is aimed to investigate the role of Nogo-B on platelet function in DM. Methods and Results: Nogo-B is highly expressed in platelets from healthy individual. Platelets from DM patients and diabetic mice have decreased Nogo-B level. Using Streptozotocin (STZ) induced diabetic mouse model, we show that loss of Nogo (Nogo-/- mice) decreased platelet number, increased mean platelet volume and prolonged bleeding time compared to wild-type (WT) mice. Platelets from Nogo-/- mice were hyperactive with higher JONA and P-selectin surface expression compared to WT mice. Loss of Nogo increased thrombin and collagen induced platelet aggregation. Furthermore, platelets from diabetic Nogo-/- mice show elevated reactive oxygen species (ROS) production, decreased mitochondria membrane potential and increased apoptosis, which can be rescued by antioxidant N-acetyl-L-cysteine. Mechanistically, we show Nogo-B prevented sequestration of antiapoptotic proteins Bcl-xL and Bcl-2 induced by hyperglycemia, subsequently protected against platelet mitochondrial damage, ROS production, caspase-3 activation and apoptosis. Conclusion: These findings demonstrate that Nogo-B protects against ER stress induced platelet apoptosis and hyperactivation in DM by regulating Bcl-xL and Bcl-2 sequestration and mitochondrial damage. This novel pathway may provide therapeutic targets for thrombotic complications in diabetes mellitus.

scholarly journals Increased nicotinamide adenine dinucleotide content and synthesis in Plasmodium falciparum-infected human erythrocytes

Blood ◽  
1990 ◽  
Vol 75 (8) ◽  
pp. 1705-1710 ◽  
Author(s):  
CR Zerez ◽  
EF Jr Roth ◽  
S Schulman ◽  
KR Tanaka
Keyword(s):  
Plasmodium Falciparum ◽  
Nicotinic Acid ◽  
Nicotinamide Adenine Dinucleotide ◽  
Biosynthetic Pathway ◽  
Pentose Phosphate ◽  
Nicotinamide Adenine ◽  
Nicotinamide Phosphoribosyltransferase ◽  
Nad Synthesis ◽  
Infected Rbcs ◽  
Nicotinic Acid Phosphoribosyltransferase

Abstract Plasmodium falciparum-infected red blood cells (RBCs) are characterized by increases in the activity of glycolytic enzymes. Because nicotinamide adenine dinucleotide (NAD) and NAD phosphate (NADP) are cofactors in the reactions of glycolysis and pentose phosphate shunt, we have examined NAD and NADP content in P. falciparum-infected RBCs. Although NADP content was not significantly altered, NAD content was increased approximately 10-fold in infected RBCs (66% parasitemia) compared with uninfected control RBCs. To determine the mechanism for the increase in NAD content, we examined the activity of several NAD biosynthetic enzymes. It is known that normal human RBCs make NAD exclusively from nicotinic acid and lack the capacity to make NAD from nicotinamide. We demonstrate that infected RBCs have readily detectable nicotinamide phosphoribosyltransferase (NPRT), the first enzyme in the NAD biosynthetic pathway that uses nicotinamide, and abundant nicotinamide deamidase, the enzyme that converts nicotinamide to nicotinic acid, thereby indicating that infected RBCs can make NAD from nicotinamide. In addition, infected RBCs have a threefold increase in nicotinic acid phosphoribosyltransferase (NAPRT), the first enzyme in the NAD biosynthetic pathway that uses nicotinic acid. Thus, the increase in NAD content in P falciparum-infected RBCs appears to be mediated by increases in NAD synthesis from both nicotinic acid and nicotinamide.

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