Functional characterization of potential epigenetically regulated zinc finger proteins important for malaria parasite transmission

• Applicant: Che Julius Ngwa, Ph.D.
• Subject Area: Parasitology and Biology of Tropical Infectious Disease Pathogens ; Cell Biology
• Term: from 2018 to 2022
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 407527076

• Final Report Year: 2023

Final Report Abstract

Epigenetic mechanisms have gained increasing attention due to their crucial roles in regulating gene expression and, in consequence cell fate. A tight control of gene regulation is particularly important for cells with high replication rates including protozoan parasites like Plasmodium falciparum, the causative agent of the deadly malaria tropica. While epigenetic control mechanisms have been studied extensively in the asexual blood stages of P. falciparum, little is known about these mechanisms in gametocytes. These transmissible stages develop in the human red blood cells during a period of 10 days and once being taken up by a bloodfeeding Anopheles mosquito undergo gametogenesis to initiate sexual reproduction. Gametocytes thus play crucial for roles for human-to-mosquito transmission of the malaria parasite. During this DFG funded project, we sought to functionally characterize zinc finger proteins (ZFPs) identified to be regulated by epigenetic mechanisms in the gametocyte stages of the malaria parasite P. falciparum. ZFPs are a diverse family of zinc ion-binding proteins that serve as interactors for DNAs, RNAs, and proteins and which among others function as transcription factors. Although the P. falciparum genome encodes more than 170 proteins with zinc finger domains, to date not much is known about their roles during the life cycle of the malaria parasite. The project funding has enabled us to unveil the role of three ZFPs in the regulation of gene expression in the gametocyte stages of P. falciparum. We have demonstrated that one of the ZFPs named ZNF4 is important for male gametocyte exflagellation through the regulation of male enriched genes. We also identified a RING- ZFP, PfRNF1 with RNA-binding E3 ligase activity which we suggest to link RNA dependent processes with protein ubiquitination to regulate gene expression in gametocytes. The funding also allowed us to characterize the CCCH-ZFP, Pfmd3 where we show that it is a male specific RNA binding protein important for asexual blood stage replication and gametocyte exflagellation. In conclusion, the funds have enabled us to shed more light in the regulation of gene expression in the gametocyte stages of the malaria parasite P. falciparum by ZFPs and has highlighted role of ZFPs in gene regulation in male gametocytes. The data gained from this project has opened up research for the exploited of ZFPs as targets for malaria transmission blocking strategies.

Publications

• Zinc finger proteins of Plasmodium falciparum. Cellular Microbiology, 23(12).
  Ngwa, Che Julius; Farrukh, Afia & Pradel, Gabriele
  
• Evaluation of Chiral Organosulfur Compounds on Their Activity against the Malaria Parasite Plasmodium falciparum. Tropical Medicine and Infectious Disease, 7(12), 416.
  Ngwa, Che; Stratmann, Rabea; Musabyimana, Jean; Pannen, Kristina; Schöbel, Jan-Hendrik; Frings, Marcus; Schiffers, Ingo; Quaranta, Calogero; Koschmieder, Steffen; Chatain, Nicolas; Pradel, Gabriele & Bolm, Carsten
  
• Plasmodium falciparum S-Adenosylmethionine Synthetase Is Essential for Parasite Survival through a Complex Interaction Network with Cytoplasmic and Nuclear Proteins. Microorganisms, 10(7), 1419.
  Musabyimana, Jean Pierre; Distler, Ute; Sassmannshausen, Juliane; Berks, Christina; Manti, Janice; Bennink, Sandra; Blaschke, Lea; Burda, Paul-Christian; Flammersfeld, Ansgar; Tenzer, Stefan; Ngwa, Che Julius & Pradel, Gabriele
  
• The Plasmodium falciparum CCCH Zinc Finger Protein ZNF4 Plays an Important Role in Gametocyte Exflagellation through the Regulation of Male Enriched Transcripts. Cells, 11(10), 1666.
  Hanhsen, Borja; Farrukh, Afia; Pradel, Gabriele & Ngwa, Che Julius
  
• Proximity interaction analysis of thePlasmodium falciparumputative ubiquitin ligasePfRNF1 reveals a role in RNA regulation. Cold Spring Harbor Laboratory.
  Farrukh, Afia; Musabyimana, Jean Pierre; Distler, Ute; Tenzer, Stefan; Pradel, Gabriele & Ngwa, Che Julius