Extracellular release of two peptidases dominates generation of the quorum sensing signal in Trypanosoma brucei

Trypanosomes causing African sleeping sickness use quorum sensing to control the production of transmission-competent stumpy forms in their mammalian hosts. This density-dependent process is signalled by the release of parasite peptidases whose action generates oligopeptides that stimulate the signal transduction pathway leading to stumpy formation. Using mass spectrometry analysis, we have characterised the peptidases released by Trypanosoma brucei brucei.