The heterologous systems in the study of cardosin B trafficking pathways.

Cardosins are abundant in cardoon pistils and were found to accumulate in different cell compartments: cardosin A was detected in the vacuoles of stigmatic papillae and cardosin B accumulates in the extracellular matrix of the transmitting tissue. Due to the fact that cardoon system imposes some limitations to the study of processing and trafficking events, heterologous species have been employed to study cardosins trafficking pathways. Cardosin B was successfully expressed both in Arabidopsis and Tobacco plants, where it accumulated mainly in the vacuole but it was also detected in the cell wall. The glycosylation pattern of cardosin B was replicated in these systems - high-mannose type glycans. In tobacco leaves, cardosin B is transported through the Golgi in a RAB-D2a-dependent route, and is delivered to the vacuole via the prevacuolar compartment in a RAB-F2b-dependent pathway.