The trypanosome Variant Surface Glycoprotein mRNA is stabilized by an essential unconventional RNA-binding protein

Salivarian trypanosomes cause human sleeping sickness and economically important livestock diseases, transmitted by Tsetse flies and replicating extracellularly throughout the life cycle. The surface of "bloodstream forms", which live within mammals, is coated by a monolayer of a Variant Surface Glycoprotein (VSG). Switching of the expressed VSG gene enables the parasites to evade adaptive immunity. Up until now, the mechanism by which VSG mRNA stability is maintained was unknown. To identify proteins specifically interacting with VSG mRNA (and alpha tubulin as control), we performed RNA-antisense purifications (RAP) following instructions published by McHugh et al. 2018 with some modifications.