TY - JOUR A1 - Rohde, P. A1 - Hincha, Dirk K. A1 - Heyer, Arnd G. T1 - Heterosis in the freezing tolerance of crosses between two Arabidopsis thaliana accessions (Columbia-0 and C24) that show differences in non-acclimated and acclimated freezing tolerance Y1 - 2004 SN - 0960-7412 ER - TY - JOUR A1 - Thalhammer, Anja A1 - Hundertmark, Michaela A1 - Popova, Antoaneta V. A1 - Seckler, Robert A1 - Hincha, Dirk K. T1 - Interaction of two intrinsically disordered plant stress proteins (COR15A and COR15B) with lipid membranes in the dry state N2 - COR15A and COR15B form a tandem repeat of highly homologous genes in Arabidopsis thaliana. Both genes are highly cold induced and the encoded proteins belong to the Pfam LEA_4 group (group 3) of the late embryogenesis abundant (LEA) proteins. Both proteins were predicted to be intrinsically disordered in solution. Only COR15A has previously been characterized and it was shown to be localized in the soluble stroma fraction of chloroplasts. Ectopic expression of COR15A in Arabidopsis resulted in increased freezing tolerance of both chloroplasts after freezing and thawing of intact leaves and of isolated protoplasts frozen and thawed in vitro. In the present study we have generated recombinant mature COR15A and COR15B for a comparative study of their structure and possible function as membrane protectants. CD spectroscopy showed that both proteins are predominantly unstructured in solution and mainly a-helical after drying. Both proteins showed similar effects on the thermotropic phase behavior of dry liposomes. A decrease in the gel to liquid-crystalline phase transition temperature depended on both the unsaturation of the fatty acyl chains and lipid headgroup structure. FTIR spectroscopy indicated no strong interactions between the proteins and the lipid phosphate and carbonyl groups, but significant interactions with the galactose headgroup of the chloroplast lipid monogalactosyldiacylglycerol. These findings were rationalized by modeling the secondary structure of COR15A and COR15B. Helical wheel projection indicated the presence of amphipathic a-helices in both proteins. The helices lacked a clear separation of positive and negative charges on the hydrophilic face, but contained several hydroxylated amino acids. Y1 - 2010 UR - http://www.sciencedirect.com/science/journal/00052736 U6 - https://doi.org/10.1016/j.bbamem.2010.05.015 SN - 0005-2736 ER - TY - JOUR A1 - Hundertmark, Michaela A1 - Dimova, Rumiana A1 - Lengefeld, Jan A1 - Seckler, Robert A1 - Hincha, Dirk K. T1 - The intrinsically disordered late embryogenesis abundant protein LEA18 from Arabidopsis thaliana modulates membrane stability through binding and folding. N2 - Intrinsically disordered proteins (IDPs) constitute a substantial part of cellular proteomes. Late embryogenesis abundant (LEA) proteins are mostly predicted to be IDPs associated with dehydration tolerance in many plant, animal and bacterial species. Their functions, however, are largely unexplored and also their structure and interactions with potential target molecules have only recently been experimentally investigated in a small number of proteins. Here, we report on the structure and interactions with membranes of the Pfam LEA_1 protein LEA18 from the higher plant Arabidopsis thaliana. This functionally uncharacterized positively charged protein specifically aggregated and destabilized negatively charged liposomes. Isothermal titration calorimetry showed binding of the protein to both charged and uncharged membranes. LEA18 alone was largely unstructured in solution. While uncharged membranes had no influence on the secondary structure of LEA18, the protein partially folded into ;-sheet structure in the presence of negatively charged liposomes. These data suggest that LEA18 does not function as a membrane stabilizing protein, as suggested for other LEA proteins. Instead, a possible function of LEA18 could be the composition-dependent modulation of membrane stability, e.g., during signaling or vesicle-mediated transport. Research Highlights Y1 - 2011 SN - 0006-3002 ER - TY - JOUR A1 - Popova, Antoaneta V. A1 - Hundertmark, Michaela A1 - Seckler, Robert A1 - Hincha, Dirk K. T1 - Structural transitions in the intrinsically disordered plant dehydration stress protein LEA7 upon drying are modulated by the presence of membranes JF - Biochimica et biophysica acta : Biomembranes N2 - Dehydration stress-related late embryogenesis abundant (LEA) proteins have been found in plants, invertebrates and bacteria. Most LEA proteins are unstructured in solution, but some fold into amphipathic a-helices during drying. The Pfam LEA_4 (Group 3) protein LEA7 from the higher plant Arabidopsis thaliana was predicted to be 87% alpha-helical, while CD spectroscopy showed it to be largely unstructured in solution and only 35% alpha-helical in the dry state. However, the dry protein contained 15% beta-sheets. FTIR spectroscopy revealed the (beta-sheets to be largely due to aggregation. beta-Sheet content was reduced and alpha-helix content increased when LEA7 was dried in the presence of liposomes with secondary structure apparently influenced by lipid composition. Secondary structure was also affected by the presence of membranes in the fully hydrated state. A temperature-induced increase in the flexibility of the dry protein was also only observed in the presence of membranes. Functional interactions of LEA7 with membranes in the dry state were indicated by its influence on the thermotropic phase transitions of the lipids and interactions with the lipid headgroup phosphates. KW - Desiccation KW - CD spectroscopy KW - FTIR spectroscopy KW - LEA protein KW - Protein-membrane interactions KW - Protein secondary structure Y1 - 2011 U6 - https://doi.org/10.1016/j.bbamem.2011.03.009 SN - 0005-2736 VL - 1808 IS - 7 SP - 1879 EP - 1887 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Hundertmark, Michaela A1 - Popova, Antoaneta V. A1 - Rausch, Saskia A1 - Seckler, Robert A1 - Hincha, Dirk K. T1 - Influence of drying on the secondary structure of intrinsically disordered and globular proteins JF - Biochemical and biophysical research communications N2 - Circular dichroism (CD) spectroscopy of five Arabidopsis late embryogenesis abundant (LEA) proteins constituting the plant specific families LEA_5 and LEA_6 showed that they are intrinsically disordered in solution and partially fold during drying. Structural predictions were comparable to these results for hydrated LEA_6, but not for LEA_5 proteins. FTIR spectroscopy showed that verbascose, but not sucrose, strongly affected the structure of the dry proteins. The four investigated globular proteins were only mildly affected by drying in the absence, but strongly in the presence of sugars. These data highlight the larger structural flexibility of disordered compared to globular proteins and the impact of sugars on the structure of both disordered and globular proteins during drying. KW - Desiccation KW - CD spectroscopy KW - FTIR spectroscopy KW - Intrinsically disordered proteins KW - LEA proteins KW - Protein secondary structure Y1 - 2012 U6 - https://doi.org/10.1016/j.bbrc.2011.11.067 SN - 0006-291X VL - 417 IS - 1 SP - 122 EP - 128 PB - Elsevier CY - San Diego ER - TY - JOUR A1 - Sprenger, Heike A1 - Rudack, Katharina A1 - Schudoma, Christian A1 - Neumann, Arne A1 - Seddig, Sylvia A1 - Peters, Rolf A1 - Zuther, Ellen A1 - Kopka, Joachim A1 - Hincha, Dirk K. A1 - Walther, Dirk A1 - Koehl, Karin T1 - Assessment of drought tolerance and its potential yield penalty in potato JF - Functional plant biology : an international journal of plant function N2 - Climate models predict an increased likelihood of seasonal droughts for many areas of the world. Breeding for drought tolerance could be accelerated by marker-assisted selection. As a basis for marker identification, we studied the genetic variance, predictability of field performance and potential costs of tolerance in potato (Solanum tuberosum L.). Potato produces high calories per unit of water invested, but is drought-sensitive. In 14 independent pot or field trials, 34 potato cultivars were grown under optimal and reduced water supply to determine starch yield. In an artificial dataset, we tested several stress indices for their power to distinguish tolerant and sensitive genotypes independent of their yield potential. We identified the deviation of relative starch yield from the experimental median (DRYM) as the most efficient index. DRYM corresponded qualitatively to the partial least square model-based metric of drought stress tolerance in a stress effect model. The DRYM identified significant tolerance variation in the European potato cultivar population to allow tolerance breeding and marker identification. Tolerance results from pot trials correlated with those from field trials but predicted field performance worse than field growth parameters. Drought tolerance correlated negatively with yield under optimal conditions in the field. The distribution of yield data versus DRYM indicated that tolerance can be combined with average yield potentials, thus circumventing potential yield penalties in tolerance breeding. KW - performance prediction KW - Solanum tuberosum KW - tolerance index KW - target environment Y1 - 2015 U6 - https://doi.org/10.1071/FP15013 SN - 1445-4408 SN - 1445-4416 VL - 42 IS - 7 SP - 655 EP - 667 PB - CSIRO CY - Clayton ER - TY - JOUR A1 - Navarro-Retamal, Carlos A1 - Bremer, Anne A1 - Alzate-Morales, Jans H. A1 - Caballero, Julio A1 - Hincha, Dirk K. A1 - Gonzalez, Wendy A1 - Thalhammer, Anja T1 - Molecular dynamics simulations and CD spectroscopy reveal hydration-induced unfolding of the intrinsically disordered LEA proteins COR15A and COR15B from Arabidopsis thaliana JF - Physical chemistry, chemical physics : a journal of European Chemical Societies N2 - The LEA (late embryogenesis abundant) proteins COR15A and COR15B from Arabidopsis thaliana are intrinsically disordered under fully hydrated conditions, but obtain alpha-helical structure during dehydration, which is reversible upon rehydration. To understand this unusual structural transition, both proteins were investigated by circular dichroism (CD) and molecular dynamics (MD) approaches. MD simulations showed unfolding of the proteins in water, in agreement with CD data obtained with both HIS-tagged and untagged recombinant proteins. Mainly intramolecular hydrogen bonds (H-bonds) formed by the protein backbone were replaced by H-bonds with water molecules. As COR15 proteins function in vivo as protectants in leaves partially dehydrated by freezing, unfolding was further assessed under crowded conditions. Glycerol reduced (40%) or prevented (100%) unfolding during MD simulations, in agreement with CD spectroscopy results. H-bonding analysis indicated that preferential exclusion of glycerol from the protein backbone increased stability of the folded state. Y1 - 2016 U6 - https://doi.org/10.1039/c6cp02272c SN - 1463-9076 SN - 1463-9084 VL - 18 SP - 25806 EP - 25816 PB - Royal Society of Chemistry CY - Cambridge ER - TY - GEN A1 - Navarro-Retamal, Carlos A1 - Bremer, Anne A1 - Alzate-Morales, Jans H. A1 - Caballero, Julio A1 - Hincha, Dirk K. A1 - González, Wendy A1 - Thalhammer, Anja T1 - Molecular dynamics simulations and CD spectroscopy reveal hydration-induced unfolding of the intrinsically disordered LEA proteins COR15A and COR15B from Arabidopsis thaliana N2 - The LEA (late embryogenesis abundant) proteins COR15A and COR15B from Arabidopsis thaliana are intrinsically disordered under fully hydrated conditions, but obtain α-helical structure during dehydration, which is reversible upon rehydration. To understand this unusual structural transition, both proteins were investigated by circular dichroism (CD) and molecular dynamics (MD) approaches. MD simulations showed unfolding of the proteins in water, in agreement with CD data obtained with both HIS-tagged and untagged recombinant proteins. Mainly intramolecular hydrogen bonds (H-bonds) formed by the protein backbone were replaced by H-bonds with water molecules. As COR15 proteins function in vivo as protectants in leaves partially dehydrated by freezing, unfolding was further assessed under crowded conditions. Glycerol reduced (40%) or prevented (100%) unfolding during MD simulations, in agreement with CD spectroscopy results. H-bonding analysis indicated that preferential exclusion of glycerol from the protein backbone increased stability of the folded state. T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 321 Y1 - 2016 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-394503 SP - 25806 EP - 25816 ER - TY - JOUR A1 - Hilker, Monika A1 - Schwachtje, Jens A1 - Baier, Margarete A1 - Balazadeh, Salma A1 - Bäurle, Isabel A1 - Geiselhardt, Sven A1 - Hincha, Dirk K. A1 - Kunze, Reinhard A1 - Mueller-Roeber, Bernd A1 - Rillig, Matthias G. A1 - Rolff, Jens A1 - Schmülling, Thomas A1 - Steppuhn, Anke A1 - van Dongen, Joost A1 - Whitcomb, Sarah J. A1 - Wurst, Susanne A1 - Zuther, Ellen A1 - Kopka, Joachim T1 - Priming and memory of stress responses in organisms lacking a nervous system JF - Biological reviews KW - priming KW - stress signalling KW - epigenetics KW - memory KW - fitness KW - stress tolerance KW - defence KW - bet hedging Y1 - 2016 U6 - https://doi.org/10.1111/brv.12215 SN - 1464-7931 SN - 1469-185X VL - 91 SP - 1118 EP - 1133 PB - Wiley-Blackwell CY - Hoboken ER - TY - JOUR A1 - Bremer, Anne A1 - Kent, Ben A1 - Hauss, Thomas A1 - Thalhammer, Anja A1 - Yepuri, Nageshwar R. A1 - Darwish, Tamim A. A1 - Garvey, Christopher J. A1 - Bryant, Gary A1 - Hincha, Dirk K. T1 - Intrinsically Disordered Stress Protein COR15A Resides at the Membrane Surface during Dehydration JF - Biophysical journal N2 - Plants from temperate climate zones are able to increase their freezing tolerance during exposure to low, above zero temperatures in a process termed cold acclimation. During this process, several cold-regulated (COR) proteins are accumulated in the cells. One of them is COR15A, a small, intrinsically disordered protein that contributes to leaf freezing tolerance by stabilizing cellular membranes. The isolated protein folds into amphipathic a-helices in response to increased crowding conditions, such as high concentrations of glycerol. Although there is evidence for direct COR15A-membrane interactions, the orientation and depth of protein insertion were unknown. In addition, although folding due to high osmolyte concentrations had been established, the folding response of the protein under conditions of gradual dehydration had not been investigated. Here we show, using Fourier transform infrared spectroscopy, that COR15A starts to fold into a-helices already under mild dehydration conditions (97% relative humidity (RH), corresponding to freezing at -3 degrees C) and that folding gradually increases with decreasing RH. Neutron diffraction experiments at 97 and 75% RH established that the presence of COR15A had no significant influence on the structure of 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine (POPC) membranes. However, using deuterated POPC we. could clearly establish that COR15A interacts with the membranes and penetrates below the headgroup region into the upper part of the fatty acyl chain region. This localization is in agreement with our hypothesis that COR15A-membrane interaction is at least, in part, driven by a hydrophobic interaction between the lipids and the hydrophobic face of the amphipathic protein alpha-helix. Y1 - 2017 U6 - https://doi.org/10.1016/j.bpj.2017.06.027 SN - 0006-3495 SN - 1542-0086 VL - 113 SP - 572 EP - 579 PB - Cell Press CY - Cambridge ER -