Oral Presentation AUS-oMicS 2025

miniTurbo BioID proximity labelling for identification of interacting partners of Apicomplexan specific regulatory protein Alba4 in malaria parasites. (#10)

Meghan E Zadow 1 2 , Ghizal Siddiqui 3 , Joshua P Morrow 3 , Darren J Creek 3 , Chris A MacRaild 3 , Danny W Wilson 1 2 4
  1. Research Centre for Infectious Diseases, School of Biological Sciences, University of Adelaide, Adelaide 5005, South Australia
  2. Institute for Photonics and Advanced Sensing (IPAS), University of Adelaide, Adelaide 5005, South Australia
  3. Drug Delivery, Disposition and Dynamics, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville 3052, Victoria, Australia
  4. Burnet Institute, Melbourne 3004, Victoria, Australia

Single-celled Plasmodium spp. malaria parasites are responsible for more than 2 million cases of severe disease annually. These parasites have distinct lifecycle stages and so strict regulation of gene and protein expression is critical for stage transition and parasite survival. Despite this, the molecular mechanisms malaria parasites utilise to regulate gene and protein expression remain poorly understood. The putative malaria parasite DNA/RNA binding protein Alba4 (Acetylation lowers binding affinity) is implicated in key parasite regulatory processes including post-transcriptional regulation and stage differentiation. Here, we utilised gene-editing and miniTurbo-BioID catalysed proximity labelling to identify PfAlba4 proximal proteins in late blood stage Plasmodium falciparum parasites. Isolation of biotinylated peptides followed by mass spectrometric analysis facilitated the identification of >50 high-confidence potential protein interactors of PfAlba4. Gene ontology analysis of these high-confidence interacting protein candidates revealed negative regulation of translation as the highest enriched biological process, while single-stranded RNA binding and mRNA binding are the most enriched molecular functions. These results are supportive of a potential regulatory role for PfAlba4 in the blood stage of these parasites. Additionally, ~23% of the high confidence potential interactors are conserved Plasmodium proteins of unknown function. The gene-edited lines and high-quality preliminary interactome developed in this study will enable characterisation of PfAlba4’s essential cell-regulatory function and potentially identify additional key regulatory proteins that could be targets for antimalarial development.