GARP, or glutamic acid/alanine-rich protein, is one of a subset of major surface molecules on Trypanosoma species. They are all surface-orientated, immunodominant, and highly charged. GARP is interesting as ts expression coincides with the loss and gain of variant surface glycoprotein (VSG) molecules in the tsetse vector. It has an extended helical bundle structure that is homologous to the core surface structure of VSG, suggesting that it might replace the bloodstream VSG as the trypanosomes differentiate inside the tsetse vector after a blood-meal [1].

1: Structural characterization and epitope mapping of the glutamic acid/alanine-rich protein from Trypanosoma congolense: defining assembly on the parasite cell surface. Loveless BC, Mason JW, Sakurai T, Inoue N, Razavi M, Pearson TW, Boulanger MJ; J Biol Chem. 2011;286:20658-20665. PMID:21471223