Endosomal transport of septin mRNAs and encoded proteins in the phytopathogen Ustilago maydis

• Applicant: Professor Dr. Michael Feldbrügge
• Subject Area: Plant Cell and Developmental Biology
• Term: from 2014 to 2020
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 258378373

Endosomes transport cellular macromolecules such as lipids and proteins. These molecular carriers mainly receive their cargo from other membrane compartments. Particularly in highly polarised cells like neurons and fungal hyphae, endosomes shuttle along microtubules and carry out sophisticated functions in long-distance transport. Evidence is accumulating that these membranous carriers also transport mRNAs as unconventional cargo. However, little is known about the precise molecular function of this endosomal mRNA transport. In the phytopathogen Ustilago maydis we recently discovered that septin mRNA and protein transport on endosomes is important for correct formation of septin filaments at the hyphal growth pole. We propose a novel cell biological mechanism, namely endosome-coupled translation, which is important for loading of endosomes with septins for their correct assembly and transport. Here, we challenge this hypothesis by investigating local translation in vivo. Moreover, we will address whether all four septins co-localise on endosomes as well as in filaments and test whether this is dependent of mRNA transport. Thus, we will gain new insights in the molecular connection of mRNA transport, membrane trafficking and septin biology.

• DFG Programme: Research Grants
• International Connection: Switzerland
• Participating Person: Dr. Jeffrey A. Chao