Niessing Group > Research Interests
NEW:
- A Review on mRNA localization in yeast
(Heym & Niessing, CMLS 2011) [PDF]
- A study on the assembly of specific mRNA transport complexes
(Müller et al. PLoS Biol 2011) [PDF]
- Book chapter on RNA-binding proteins in fungi [Pubmed Bookshelf]
RNA localization and intracellular transport
We use a combination of X-ray crystallography, biophysical and biochemical approaches to understand mechanisms of motor-cargo interaction and the assembly of active cargo complexes. As a first model, we analyze the directional transport of ASH1 mRNA in S. cerevisiae. Besides mRNA, this cargo-transport complex consists of the myosin motor Myo4p, its bound adapter She3p, and the RNA-cargo binding protein She2p.
We determined the X-ray structures of the cargo protein She2p and found that it has a novel protein fold (Niessing et al. 2004). In solution, She2p is a tetramer required for its function in vitro and in vivo (Müller et al. 2009).
We characterized the binding of the myosin motor Myo4p to its cargo adapter She3p (Heuck et al. 2007). We found that the type V myosin motor Myo4p is strictly monomeric in solution. Structure determination of the Myo4p globular tail revealed strong similarity to membrane-tethering complexes (Heuck et al. 2010), suggesting a role of this domain not only in cargo binding, but also in mRNP anchoring.
We also study transport factors from neurons. We determined the crystal structure of the neuronal RNA-binding protein Pur-alpha and showed by SAXS that it adopts an unusual topology in solution (Graebsch et al. 2009, 2010).
Our long-term goal is to understand how core factors of large multiprotein complexes interact to (i) detect their cargo, (ii) assemble into functional complexes in response to cargo recognition and (iii) translocate their cargo through the cytoplasm. We aim to extend our understanding to transport processes in higher eukaryotes.