Chromodomain Protein Interacts with H3K9me3 and Controls RBC Rosette Formation by Regulating the Expression of a Subset of RIFINs in the Malaria Parasite

• Published in: Journal of molecular biology 2022-06, Vol.434 (12), p.167601, Article 167601
• Main Authors: Sethumadhavan, Devadathan Valiyamangalath, Tiburcio, Marta, Kanyal, Abhishek, Jabeena, C.A., Govindaraju, Gayathri, Karmodiya, Krishanpal, Rajavelu, Arumugam
• Format: Article
• Language: English
• Subjects: Animals; Epigenesis, Genetic; epigenetics; Erythrocytes - immunology; Erythrocytes - parasitology; Gene Deletion; Histones - metabolism; Malaria, Falciparum - parasitology; methyl-binding proteins; Multigene Family; Plasmodium falciparum; Plasmodium falciparum - genetics; Plasmodium falciparum - pathogenicity; Protozoan Proteins - genetics; Protozoan Proteins - metabolism; RIFINs; Rosette Formation; virulence; Virulence - genetics
• ISSN: 0022-2836; 1089-8638
• DOI: 10.1016/j.jmb.2022.167601

[Display omitted] •The human malaria parasite Plasmodium falciparum expresses virulence proteins on the surface of infected RBCs.•P. falciparum chromodomain containing protein (CDP) binds to the H3K9me3 mark.•Interaction of PfCDP – H3K9me3 suppresses the expression of subsets of RIFINs family proteins.•Deletion of PfCDP in P. falciparum upregulates the subsets of RIFINs expression and promotes the RBC resetting. Plasmodium falciparum expresses clonally variant proteins on the surface of infected erythrocytes to evade the host immune system. The clonally variant multigene families include var, rifin, and stevor, which express Erythrocyte Membrane Protein 1 (EMP1), Repetitive Interspersed Families of polypeptides (RIFINs), and Sub-telomeric Variable Open Reading frame (STEVOR) proteins, respectively. The rifins are the largest multigene family and are essentially involved in the RBC rosetting, the hallmark of severe malaria. The molecular regulators that control the RIFINs expression in Plasmodium spp. have not been reported so far. This study reports a chromodomain-containing protein (PfCDP) that binds to H3K9me3 modification on P. falciparum chromatin. Conditional deletion of the chromodomain (CD) gene in P. falciparum using an inducible DiCre-LoxP system leads to selective up-regulation of a subset of virulence genes, including rifins, a few var, and stevor genes. Further, we show that PfCDP conditional knockout (PfΔCDP) promotes RBC rosette formation. This study provides the first evidence of an epigenetic regulator mediated control on a subset of RIFINs expression and RBC rosetting by P. falciparum.