LOEWE Zentrum für
& Bioressourcen

Seminar announcement 2nd April 2014

Dr. Christopher Grefen

Improving protein-protein interaction techniques to explore water use efficiency in plants

Improving protein‐protein interaction techniques to explore water use efficiency in plants Throughout the life cycle of plants, from germination to senescence, cell elongation and swelling of cells regulates a variety of important functions. Balancing turgor pressure and delivery of membrane material facilitates and fine‐tunes these processes; however our understanding of the underlying mechanisms remains scant.

Work from our lab suggests that the plasma membrane SNARE SYP121 interacts with some of the Kv‐like K+‐channels altering their gating behaviour. This interaction challenged our view of SNAREs being solely involved in facilitating membrane fusions. Interestingly, the domain that is involved in the binding of the channel is not the promiscuous SNARE‐domain that facilitates SNARE‐core‐complex formation, but a short N‐terminal sequence. This sequence shows homology to S/M‐related binding sites which themselves are important cofactors that regulate the SNAREs ability to form SNARE‐complexes that enable vesicle fusion.

In vitro and in vivo analysis including split‐ubiquitin, ratiometric bimolecular fluorescence complementation, heterologous expression and electrophysiological analyses demonstrate physical interaction and impact on K+ transport. Subsequent studies have since indicated a wider scope to the SNARE‐channel interactions and analysis of the peptide domains essential for these interactions now offer important clues to possible mechanisms that may coordinate inorganic solute uptake with membrane expansion for cell growth and volume control.

The group of Dr. Christopher Grefen is working at the cross road of membrane traffic and ion transport in plants at the University of Tübingen.

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