Proteomic analysis of Giardia lamblia ESV and PV organelle enriched fractions

ABSTRACT: The protozoan Giardia lamblia is a unique biological model to investigate minimal cellular mechanisms because it is an early‐diverged eukaryote that has undergone reductive evolution and has minimized or lost organelles such as mitochondria, peroxisomes, the endo-lysosomal system and a Golgi apparatus. Giardia trophozoites reside in the host intestines where they largely depend on scavenging metabolites from the surrounding through endocytosis and/or pinocytosis. A canonical endo‐lysosomal system however is inexistent, but small peripheral vesicles (PVs) have been described which have partial endocytic characteristics but lack endocytic hallmarks: (i) unlike the dynamic multivesicular endo-lysosomal system in mammalian cells, PVs have a fixed location at the cell periphery and show no lateral cargo exchange; (ii) PVs lack maturation-specific markers. For transmission to a new host, motile trophozoites differentiate to cysts and thus secrete a protective cyst wall (CW). Giardia however has no Golgi or to organize regulated secretion of CW material. Instead, differentiating cells generate specialized organelles termed encystation‐specific vesicles (ESVs), being stage-regulated Golgi relic organelles dedicated to post‐translational maturation of the CW material. Basic sorting processes in maturing ESVs have been identified recently, but underlying mechanisms remain unknown. To define the first proteome of ESVs and PVs, we used a new strategy combining flow cytometry-based organelle sorting with in silico filtration of mass spectrometry data.

INSTRUMENT(S): LTQ Orbitrap

ORGANISM(S): Giardia Lamblia Atcc 50803

TISSUE(S): Permanent Cell Line Cell

DISEASE(S): Giardiasis

SUBMITTER: Adrian Hehl  

LAB HEAD: Adrian B. Hehl

PROVIDER: PXD000694 | Pride | 2014-03-11

REPOSITORIES: Pride