Dataset Information

Interaction Analysis of a Plasmodium falciparum PHISTa-like Protein and PfEMP1 Proteins.

ABSTRACT: Plasmodium falciparum extensively remodels host cells by translocating numerous proteins into the cytoplasm of red blood cells (RBCs) after invasion. Among these exported proteins, members of the Plasmodium helical interspersed subtelomeric (PHIST) family are crucial for host cell remodeling and host-parasite interactions, and thereby contribute to malaria pathogenesis. Herein, we explored the function of PF3D7_1372300, a member of the PHIST/PHISTa-like subfamily. PF3D7_1372300 was highly transcribed and expressed during the blood stage of P. falciparum, and distributed throughout RBCs, but most abundant at the erythrocyte membrane. Specific interaction of PF3D7_1372300 with the cytoplasmic tail of P. falciparum erythrocyte membrane protein 1 (PfEMP1) was revealed by immunofluorescence assay, in vitro intermolecular interaction assays. The interaction sites of PF3D7_1372300 with PfEMP1 ATS domain were found involved more than 30 amino acids (aa) at several positions. The findings deepen our understanding of host-parasite interactions and malaria pathogenesis.

SUBMITTER: Yang B

PROVIDER: S-EPMC7691434 | biostudies-literature | 2020

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

Interaction Analysis of a Plasmodium falciparum PHISTa-like Protein and PfEMP1 Proteins.

Yang Baoling B Wang Xiaofeng X Jiang Ning N Sang Xiaoyu X Feng Ying Y Chen Ran R Wang Xinyi X Chen Qijun Q

Frontiers in microbiology 20201113

Plasmodium falciparum extensively remodels host cells by translocating numerous proteins into the cytoplasm of red blood cells (RBCs) after invasion. Among these exported proteins, members of the Plasmodium helical interspersed subtelomeric (PHIST) family are crucial for host cell remodeling and host-parasite interactions, and thereby contribute to malaria pathogenesis. Herein, we explored the function of PF3D7_1372300, a member of the PHIST/PHISTa-like subfamily. PF3D7_1372300 was ...[more]

PMID: 33281807

Similar Datasets

Project description:The Plasmodium falciparum erythrocyte membrane protein 1 (PfEMP1) family plays a central role in antigenic variation and cytoadhesion of P. falciparum infected erythrocytes. PfEMP1 proteins/var genes are classified into three main subfamilies (UpsA, UpsB, and UpsC) that are hypothesized to have different roles in binding and disease. To investigate whether these subfamilies have diverged in binding specificity and test if binding could be predicted by adhesion domain classification, we generated a panel of 19 parasite lines that primarily expressed a single dominant var transcript and assayed binding against 12 known host receptors. By limited dilution cloning, only UpsB and UpsC var genes were isolated, indicating that UpsA var gene expression is rare under in vitro culture conditions. Consequently, three UpsA variants were obtained by rosette purification and selection with specific monoclonal antibodies to create a more representative panel. Binding assays showed that CD36 was the most common adhesion partner of the parasite panel, followed by ICAM-1 and TSP-1, and that CD36 and ICAM-1 binding variants were highly predicted by adhesion domain sequence classification. Binding to other host receptors, including CSA, VCAM-1, HABP1, CD31/PECAM, E-selectin, Endoglin, CHO receptor "X", and Fractalkine, was rare or absent. Our findings identify a category of larger PfEMP1 proteins that are under dual selection for ICAM-1 and CD36 binding. They also support that the UpsA group, in contrast to UpsB and UpsC var genes, has diverged from binding to the major microvasculature receptor CD36 and likely uses other mechanisms to sequester in the microvasculature. These results demonstrate that CD36 and ICAM-1 have left strong signatures of selection on the PfEMP1 family that can be detected by adhesion domain sequence classification and have implications for how this family of proteins is specializing to exploit hosts with varying levels of anti-malaria immunity.

Project description:Rosetting, namely the capacity of the Plasmodium falciparum-infected red blood cells to bind uninfected RBCs, is commonly observed in African children with severe malaria. Rosetting results from specific interactions between a subset of variant P. falciparum erythrocyte membrane protein 1 (PfEMP1) adhesins encoded by var genes, serum components and RBC receptors. Rosette formation is a redundant phenotype, as there exists more than one var gene encoding a rosette-mediating PfEMP1 in each genome and hence a diverse array of underlying interactions. Moreover, field diversity creates a large panel of rosetting-associated serotypes and studies with human immune sera indicate that surface-reacting antibodies are essentially variant-specific. To gain better insight into the interactions involved in rosetting and map surface epitopes, a panel of monoclonal antibodies (mAbs) was investigated.Monoclonal antibodies were isolated from mice immunized with PfEMP1-VarO recombinant domains. They were characterized using ELISA and reactivity with the native PfEMP1-VarO adhesin on immunoblots of reduced and unreduced extracts, as well as SDS-extracts of Palo Alto 89F5 VarO schizonts. Functionality was assessed using inhibition of Palo Alto 89F5 VarO rosette formation and disruption of Palo Alto 89F5 VarO rosettes. Competition ELISAs were performed with biotinylated antibodies against DBL1 to identify reactivity groups. Specificity of mAbs reacting with the DBL1 adhesion domain was explored using recombinant proteins carrying mutations abolishing RBC binding or binding to heparin, a potent inhibitor of rosette formation.Domain-specific, surface-reacting mAbs were obtained for four individual domains (DBL1, CIDR1, DBL2, DBL4). Monoclonal antibodies reacting with DBL1 potently inhibited the formation of rosettes and disrupted Palo Alto 89F5 VarO rosettes. Most surface-reactive mAbs and all mAbs interfering with rosetting reacted on parasite immunoblots with disulfide bond-dependent PfEMP1 epitopes. Based on competition ELISA and binding to mutant DBL1 domains, two distinct binding sites for rosette-disrupting mAbs were identified in close proximity to the RBC-binding site.Rosette-inhibitory antibodies bind to conformation-dependent epitopes located close to the RBC-binding site and distant from the heparin-binding site. These results provide novel clues for a rational intervention strategy that targets rosetting.

Dataset Information

Interaction Analysis of a Plasmodium falciparum PHISTa-like Protein and PfEMP1 Proteins.

Publications

Interaction Analysis of a <i>Plasmodium falciparum</i> PHISTa-like Protein and PfEMP1 Proteins.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets