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.
- 94 -
