TY  - JOUR
A1  - Navarro-Retamal, Carlos
A1  - Bremer, Anne
A1  - Ingolfsson, Helgi I.
A1  - Alzate-Morales, Jans
A1  - Caballero, Julio
A1  - Thalhammer, Anja
A1  - Gonzalez, Wendy
A1  - Hincha, Dirk K.
T1  - Folding and Lipid Composition Determine Membrane Interaction of the Disordered Protein COR15A
T2  - Biophysical journal
N2  - Plants from temperate climates, such as the model plant Arabidopsis thaliana, are challenged with seasonal low temperatures that lead to increased freezing tolerance in fall in a process termed cold acclimation. Among other adaptations, this involves the accumulation of cold-regulated (COR) proteins, such as the intrinsically disordered chloroplast-localized protein COR15A. Together with its close homolog COR15B, it stabilizes chloroplast membranes during freezing. COR15A folds into amphipathic alpha-helices in the presence of high concentrations of low-molecular-mass crowders or upon dehydration. Under these conditions, the (partially) folded protein binds peripherally to membranes. In our study, we have used coarse-grained molecular dynamics simulations to elucidate the details of COR15A-membrane binding and its effects on membrane structure and dynamics. Simulation results indicate that at least partial folding of COR15A and the presence of highly unsaturated galactolipids in the membranes are necessary for efficient membrane binding. The bound protein is stabilized on the membrane by interactions of charged and polar amino acids with galactolipid headgroups and by interactions of hydrophobic amino acids with the upper part of the fatty acyl chains. Experimentally, the presence of liposomes made from a mixture of lipids mimicking chloroplast membranes induces additional folding in COR15A under conditions of partial dehydration, in agreement with the simulation results.
Y1  - 2018
UR  - https://publishup.uni-potsdam.de/frontdoor/index/index/docId/51954
SN  - 0006-3495
SN  - 1542-0086
VL  - 115
IS  - 6
SP  - 968
EP  - 980
PB  - Cell Press
CY  - Cambridge
ER  -