Poster Presentation Inaugural Australian Ubiquitin Summit 2025

GID/CTLH E3 ligase complex controls cell fate programs for sexual development of Plasmodium falciparum (#104)

Danushka Marapana 1 2 , Sash Lopaticki 1 2 , Balu Balan 1 2 , Kitsanapong Reaksudsan 1 2 , Simon Cobbold 1 2 , Niall Geoghegan 1 2 , Sachin Khurana 1 2 , Stephen Scally 1 2 , Peter Hickey 1 2 , Vineet Vaibhav 1 2 , Sukhdeep Spall 1 2 , Jumana Yousef 1 2 , Laura Dagley 1 , Christopher Goodman 3 , Anton Cozijnsen 3 , Geoffrey McFadden 3 , Kelly Rogers 1 2 , Aaron Jex 1 2 , David Komander 1 2 , James McCarthy 1 , Chris Tonkin 1 2 , Matthew Dixon 1 , Alan Cowman 1 2
  1. Walter and Eliza Hall Institute, Parkville, Melbourne, VIC, Australia
  2. Department of Medical Biology, University of Melbourne, Melbourne, Victoria, Australia
  3. School of BioSciences, The University of Melbourne, Melbourne, Victoria, Australia

Plasmodium falciparum, humankind’s deadliest parasite, orchestrates precisely timed developmental transitions, yet the molecular mechanisms orchestrating these shifts have remained elusive. We identify the PfGID E3 ubiquitin ligase complex as a master regulator of sexual development in P. falciparum, revealing a sophisticated multi-tiered control system integrating protein degradation and RNA regulation. The PfGID complex is required for gametocyte maturation and parasite transmission to mosquitoes, underscoring its pivotal role. PfGID governs gametocyte development by fine-tuning levels of two substrates: GD1, a novel RNA-binding protein, and PfDPL, a cryptochrome-like protein. GD1 is a key regulator of P-body dynamics by maintaining the delicate balance of translational repression essential for gametocyte maturation. Our findings reveal PfDPL regulates expression of male-specific proteins essential for gametogenesis. These findings illuminate the intricate molecular choreography underlying Plasmodium sexual development and provide insights into how single-celled eukaryotes execute cell-fate programs to navigate complex life cycles and adapt to diverse host environments.