Special projects between Bavaria and Georgia
Dept. of Biology I, Genetics
Ludwig-Maximilians-Universität, München
Department of Cellular Biology
University of Georgia
Role of organellar calcium and polyphosphate stores in stage differentiation of trypanosomes
Trypanosoma brucei is the causative agent of sleeping sickness or African trypanosomiasis. This phylogenetically distant protozoan parasite has become the preferred model for an increasing number of very unconventional molecular and biochemical mechanisms, given the availability of powerful reverse genetic tools available for its study. The organism´s life cycle is characterized by a succession of developmental stages adapted to the environments in the mammalian host or the tsetse insect vector. We are interested in the signaling mechanisms that mediate parasite-host recogition and subsequent developmental reprograming. A role of calcium in this signaling is likely but not explored so far. Acidocalcisomes, specific organelles first described in trypanosomes and later found in in a diverse array of organisms from bacteria to humans, contain large amount of pyrophosphate and divalent cations including calcium. We plan to combine our laboratories´specific expertise to investigate the role of acidocalcisomes and of calcium release in developmental signaling.
Final report
This project has connected two research groups with very different strengths, in terms of scientific questions as well as methodical approaches. The initial visit of a researcher from Munich in Athens was focussed on scientific discussions, the exchange of ideas and the planning of a research project for a graduate student from Atlanta in the laboratory in Munich. Following this planning stage, Miss Noelia Lander came to work in Munich from April 18th to May 16th. She measured the polyphosphate content of Trypanosoma cells in different functional stages, using an established method from the Docampo laboratory. The system for culturing and differentiating trypanosomes under various stress conditions is well established in Munich, and different cell lines with genetic manipulations in potentially important stress response pathways are available. Noelia Lander’s results show (1) no correlation between polyphosphate content and differentiation stage of the trypanosomes in culture. The measurements will now be repeated in Athens, using an in vivo trypanosome infection model. (2) Polyphosphate measurements in a genetically modified cell line have provided evidence for an involvement of a specific signalling protein in the cell’s response to hypo-osmotic stress. This part of the project will now be further investigated in Munich.
The BaCaTeC funding has allowed the close collaboration, including shared experiments, of two research groups in Georgia and Germany that would have been unlikely otherwise, due to the large distance between the groups. It has paved the way for further exchange between the two laboratories and the collaboration will be continued in the future.