Disordered Motifs and Domains in Cell Control - October 11-15, 2014

Disordered Motifs and Domains in Cell Control

Poster Session II

42-POS Board 18 Stress Induced Proteins in Plants: Studies of the Intrinsically Disordered Dehydrins Sylvia Röstin , Pia Harryson. Stockholm University, Stockholm, Sweden. Plants can activate an array of responses when they have to survive different environmental stresses such as low temperature or drought. One such response is the induction of stress proteins, for example the late embryonic abundant (LEA) proteins. Although the precise functions of these proteins are unknown, the general hypothesis is that they stabilise membranes, acts as metal sponges, stabilise other proteins or other cellular structures by preventing them from denature due to stress. Group 2 of the LEA proteins, the dehydrins, constitute a class of intrinsically disordered proteins that are expressed under condition of stress in plants. Characteristic to the dehydrins are some highly conserved stretches of 7-17 residues that are repetitively scattered in their sequence, the K-, S-, Y- and lysine rich segments. We have shown that the dehydrin Lti30 (K6 dehydrin) interacts and even aggregates negatively charged phospholipid vesicles and that it is detectable with light microscopic pictures and absorbance measurements. This interaction is depending on the pairs of histidins that are flanking the K- segments of Lti30. Rab18 (Y2SK2 dehydrin) shows a weak interaction, while Cor47 (SK2 dehydrin) and Lti29 (SK2 dehydrin) showed no binding at all. In this study we investigates how calcium and zinc can modify the binding of the dehydrins to phospholipid vesicles. Calcium enhanced the binding to phospholipid vesicles for the dehydrins that already showed binding capacity (Lti30 and Rab18), while it was having no effect for Cor47 and Lti29. Zinc was affecting all four dehydrins and promoted binding and aggregation of phospholipid vesicles by Cor47 and Lti29. Zinc was even increasing the aggregation of negatively charged vesicles when Lti30 and Rab18 were added.

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