Encystation deep proteome of Giardia duodenalis

ABSTRACT: Background: Cyst formation in parasitic protist Giardia duodenalis is critical to its transmission. Proteomic data is essential for the system-level understanding of the molecular mechanisms managing stage transition from a flagellated, binucleate trophozoite to a tetra-nucleate cyst. The current encystation proteome quantifies 16% of predicted protein coding genes and lacks complete coverage of the developmental transition. Given recent gains in mass spectrometry instrumentation, we have generated significantly improved proteomes for Giardia across encystation, providing framework for transcriptome-proteome correlation drawing insights into molecular networks modulating encystation in Giardia. Results: We have reproducibly identified 3,796 (64.6% of Giardia proteins) and quantified 3,402 proteins (56.12 % of Giardia proteins), tripling the currently published encystation proteome coverage. This includes timepoints from standard trophozoite growth (TY), during low-bile encystation priming (LB), mid-encystation (EC), and enriched, mature cysts (C), making this the first proteome study across the entire encystation process. This is also the first proteome analysis of trophozoites during low bile priming prior to in vitro induction of encystation, and analysis of mature cyst proteomes. Almost 28% (1,102 proteins) of the proteome is differentially changed during encystation including within proteasomal machinery, metabolic pathways and lipid metabolism, indicating a multimodal regulation in encystation. To further understand novel observations in lipid metabolism, we used hidden markov model (HMM) based domain prediction strategies and i-Tasser based structural modelling to provide evidence for the presence of three families of lipid transporters (LTP’s) StARkin (steroidogenic acute regulatory protein–related lipid transfer), ORP/Osh (Oxysterol Binding protein related protein), GLTP (Glycosphingolipid transfer protein) in Giardia. Finally, we performed functional interaction studies using in silico docking of newly identified LTP’s with corresponding lipid ligands to validate their interaction. This identified a shift in lipid species dependency in Giardia as the parasite progress towards cyst formation.

INSTRUMENT(S): LTQ Orbitrap Elite

ORGANISM(S): Giardia Lamblia Atcc 50803

TISSUE(S): Trophozoite, Binucleate Cell

DISEASE(S): Giardiasis

SUBMITTER: Samantha Emery  

LAB HEAD: Aaron Jex

PROVIDER: PXD016863 | Pride | 2023-02-08

REPOSITORIES: Pride