Subcellular protein localisation of Trypanosoma brucei bloodstream form-upregulated proteins maps stage-specific adaptations

Genome-wide subcellular protein localisation in Trypanosoma brucei, through our TrypTag project, has comprehensively dissected the molecular organisation of this important pathogen. Powerful as this resource is, T. brucei has multiple developmental forms and we previously only analysed the procyclic form. This is an insect life cycle stage, leaving the mammalian bloodstream form unanalysed. The expectation is that between life stages protein localisation would not change dramatically (completely unchanged or shifting to analogous stage-specific structures). However, this has not been specifically tested. Similarly, which organelles tend to contain proteins with stage-specific expression can be predicted from known stage specific adaptations but has not been comprehensively tested. Here, we used endogenous tagging to determine the sub-cellular localisation of the majority of proteins encoded by transcripts significantly upregulated in the bloodstream form and compared them to the existing localisation data in procyclic forms. This confirmed the localisation of known and identified the localisation of novel stage-specific proteins, giving a map of which organelles tend to contain stage specific proteins: the mitochondrion for the procyclic form, and the endoplasmic reticulum, endocytic system and cell surface in the bloodstream form.