SECRETION IN PLANTS · Development of new molecular tools to study secretion in plant cells
FP6 — Marie Curie Actions (Human Resources and Mobility)
- Duration
- 2004-06-01 → 2008-05-31
- EU contribution
- €211,002
- Participants
- 1
- Scheme
- TOK
Lines connect the coordinator with its partners.
Results in brief
Final Activity Report Summary - SECRETION IN PLANTS (Development of new molecular tools to study secretion in plant cells)
The goal of the project was the development of new molecular tools for the study of secretion in plant cells. The research work focused essentially on the characterisation of exocytose using exogenous molecular markers such as 'Intrinsically fluorescent proteins' (IFP) and enzymes (mannosidase and glucuronidase). Various aspects of protein sorting were considered, to the plasma membrane as well as to the alternative destination to the tonoplast. Collected data provided new information about the entire network of cell endomembranes. The new molecular tools developed during this project were of two kinds: new fluorescent markers, obtained as IFP chimeras, and new process-specific inhibitory molecules. The last kind of molecular tool consists of Dominant negative (DN) mutants obtained from Snares and Rabs involved in the different processes studied. The idea behind this move from the observation that inhibitory drugs specificity is dose dependent and difficult to establish in new systems. The use of a DN mutant can bypass the need of inhibitory drugs in studying secretory processes. In fact the expression in the cell system of a DN mutant can block the activity of proteic partners of the native protein with high efficiency and possibly no undesired effects. The use of DN mutants in other laboratories increased during the last years but the present project not only followed the most promising trend in this kind of studies but moved further validating with an original approach the use of more than one DN mutant at once.
Data: CORDIS, © European Union
Project objective
New molecular tools may be developed to increase quality and impact of the current research in the laboratory of Botany in Lecce but human resources are limited and potential partners geographically distant. Transfer of knowledge is needed to extend the st udy to specific functions of different SNARE proteins and develop better markers. many of the best-known secretory models in plants appear closely allied to the idea of constitutive secretion but exceptions are known. At least two exocytotic pathways exist in barley aleurone protoplasts: one, involved in cell expansion, is Ca2+ -independent and whose regulation is currently not known and an other, involved in cell damage response, is stimulated by Ca2+ and modulated by GTP-binding proteins. It is likely tha t the constitutive and regulated secretory pathways are present toghether in many different cell types. During exocytosis, vescicles fuse with the plasma membrane that results in the delivery to the plasma membrane of various kinds of material: membrane it self and membrane-associated proteins; cell wall precursors and extracellular proteins. This process must be highly controlled to modulate the arrival of very different materials in all cell kinds of a plant. In animals and yeast the situation is complex a nd many genes are involved in the process; homologue genes involved in secretion have been identified also in plants (Nt-Syr1, Knolle, Gnom, Keule, GTPases). The Syntaxin homologue Nt-Syr1 (recently re-named SYP 121) was recently isolated in a functional s creen for ABA signaling elements. Competition of a soluble variant of Nt-Syr1 with the endogenous protein, strongly affects secretion of reporter proteins, thus representing a powerfull tool to study regulated , ABA dependent, secretion. We set up a compl ex experimental system in N. tabacum to monitor secretion of reporter proteins (GFP and GUS) and cell wall polysaccharides.
Original text from CORDIS.
Participants
- Università degli Studi di Lecce · LECCECoordinatorItaly
Links
Data: CORDIS, © European Union