Biochemie pflanzlicher Membranproteine

Gebiet

Ausrichtung

Auxin is a major plant hormone that has to be properly transported and redistributed throughout the plant at all stages of a plant’s life cycle. The proteins involved in controlling and directing auxin distribution are thus key determinants of many aspects of plant growth, development and physiological responses. The PINs are a family of integral membrane proteins that play a crucial role in the export of auxin from cells, but the actual mode of action by which they mediate or control auxin transport is unknown. As PINs show no significant homology to other proteins, the lack of experimental data on their molecular properties hampers progress in this field.

The research activities of my “plant membrane protein biochemistry” group aims to address this gap in knowledge by using biochemical approaches to elucidate some of the basic structural features of PIN proteins, such as membrane topology, N-glycosylation, inter/intra-molecular disulfide bonds and oligomerisation, the last of which is a feature that is integral to the mechanism of action of many membrane transporters and receptors. Such data should reveal some of the molecular features of PIN proteins, which will aid in the interpretation of past and future studies on the involvement of PINs in plant auxin distribution.

Projekte

Fig.1 GUS-stained Arabidopsis seedling showing the expression zone of a protein

Examining possible post-translational modifications of PIN proteins

From the pattern of bands seen in western blot analysis, it is apparent that PIN proteins can be modified post-translationally and that such modifications differ between the various PIN proteins. These modifications can be altered under certain conditions, e.g. following treatment with inhibitors of various signalling pathways. We are currently investigating the nature of such modifications.

Fig.2 Proteins separated by SDS-PAGE and stained with Coomassie Blue (left) or Ponceau S (right) 

Investigating the gravitropic response in Arabidopsis CK2 mutants

We have recently discovered that Arabidopsis CK2 mutants have a faster and more accurate root gravitropic response than wild-type plants. In this project, we are presently investigating the reason for this, including analysis of changes in PIN and PID protein expression and the involvement of the ethylene signalling pathway.

The significance of light/dark transitions on plant growth and behaviour

As plants grow in cycles of light and darkness, almost every aspect of their growth and behaviour is affected to some extent by the presence or absence of light and/or by circadian rhythms.  We are interested in how plants react to light as they develop, i.e. from the first few days following germination compared to older stages.

laufende Projekte

abgeschlossene Projekte

Publikationen

Förderungsorganisationen

Kooperationen

In recent years our group published together with the following groups: