Identification and characterisation of UDP-galactofuranose transporter from the human pathogens Leishmania major and Aspergillus fumigatus
Final Report Abstract
This work identified and characterised the first UDP-Galf transporter and thus contributed to our general knowledge of this class of molecules. Importantly, we could also show that the UDP-Galf transporter of the fungal pathogen Aspergillus fumigatus is essential for the biosynthesis of galactomannan, an important surface polysaccharide. This is in contrast to the biosynthesis of other major fungal polysaccharides like ß-glucan and chitin, that are synthesised in the cytosol at the plasma membrane. Our work, however, established a clear link between galactomannan biosynthesis and the Golgi apparatus, where the transporter was localised. Thus it allowed us to propose a model for the biosynthesis of this important fungal polysaccharide according to which galactomannan would be first synthesised on a glycolipid anchor in the organelles of the secretory pathway, secreted to the plasma membrane and then transferred to the cell wall by transglycosylation. In future work, we wish to prove this model by addressing the biosynthesis of GPI-linked galactomannan. In parallel to this project, Mr. Engel was involved in two collaborative projects for which his expertise in carbohydrate analysis was required. These projects allowed the characterisation of two A. fumigatus mannosyltransferases and excluded their involvement in galactomannan biosynthesis and in fungal virulence.
Publications
- (2009). A single UDP-galactofuranose transporter is required for galactofuranosylation in Aspergillus fumigatus. J Biol Chem 284: 33859-33868
Engel J, Schmalhorst PS, Dork-Bousset T, Ferrieres V and Routier FH
- (2010). Approaching the secrets of N-glycosylation in Aspergillus fumigatus: Characterization of the AfOch1 protein. Plos One 5: e15729
Kotz A, Wagener J, Engel J, Routier FH, Echtenacher , Jacobsen I, Heesemann J and Ebel F
- (2010). The mitA gene of Aspergillus fumigatus is required for mannosylation of inositolphosphorylceramide, but is dispensable for pathogenicity. Fungal Genet Biol 47: 169-178
Kotz A, Wagener J, Engel J, Routier F, Echtenacher B, Pich A, Rohde M, Hoffmann P, Heesemann J and Ebel F
