TY  - JOUR
A1  - Brzezinka, Krzysztof
A1  - Altmann, Simone
A1  - Czesnick, Hjördis
A1  - Nicolas, Philippe
A1  - Gorka, Michal
A1  - Benke, Eileen
A1  - Kabelitz, Tina
A1  - Jähne, Felix
A1  - Graf, Alexander
A1  - Kappel, Christian
A1  - Bäurle, Isabel
T1  - Arabidopsis FORGETTER1 mediates stress-induced chromatin memory through nucleosome remodeling
JF  - eLife
N2  - Plants as sessile organisms can adapt to environmental stress to mitigate its adverse effects. As part of such adaptation they maintain an active memory of heat stress for several days that promotes a more efficient response to recurring stress. We show that this heat stress memory requires the activity of the FORGETTER1 (FGT1) locus, with fgt1 mutants displaying reduced maintenance of heat-induced gene expression. FGT1 encodes the Arabidopsis thaliana orthologue of Strawberry notch (Sno), and the protein globally associates with the promoter regions of actively expressed genes in a heat-dependent fashion. FGT1 interacts with chromatin remodelers of the SWI/ SNF and ISWI families, which also display reduced heat stress memory. Genomic targets of the BRM remodeler overlap significantly with FGT1 targets. Accordingly, nucleosome dynamics at loci with altered maintenance of heat-induced expression are affected in fgt1. Together, our results suggest that by modulating nucleosome occupancy, FGT1 mediates stress-induced chromatin memory.
Y1  - 2016
U6  - https://doi.org/10.7554/eLife.17061
SN  - 2050-084X
VL  - 5
PB  - eLife Sciences Publications
CY  - Cambridge
ER  - 
TY  - JOUR
A1  - Lämke, Jörn
A1  - Brzezinka, Krzysztof
A1  - Altmann, Simone
A1  - Bäurle, Isabel
T1  - A hit-and-run heat shock factor governs sustained histone methylation and transcriptional stress memory
JF  - The EMBO journal
N2  - In nature, plants often encounter chronic or recurring stressful conditions. Recent results indicate that plants can remember a past exposure to stress to be better prepared for a future stress incident. However, the molecular basis of this is poorly understood. Here, we report the involvement of chromatin modifications in the maintenance of acquired thermotolerance (heat stress [HS] memory). HS memory is associated with the accumulation of histone H3 lysine 4 di- and trimethylation at memory-related loci. This accumulation outlasts their transcriptional activity and marks them as recently transcriptionally active. High accumulation of H3K4 methylation is associated with hyper-induction of gene expression upon a recurring HS. This transcriptional memory and the sustained accumulation of H3K4 methylation depend on HSFA2, a transcription factor that is required for HS memory, but not initial heat responses. Interestingly, HSFA2 associates with memory-related loci transiently during the early stages following HS. In summary, we show that transcriptional memory after HS is associated with sustained H3K4 hyper-methylation and depends on a hit-and-run transcription factor, thus providing a molecular framework for HS memory.
KW  - chromatin
KW  - H3K4 methylation
KW  - heat shock transcription factor
KW  - priming
KW  - transcriptional memory
Y1  - 2016
U6  - https://doi.org/10.15252/embj.201592593
SN  - 0261-4189
SN  - 1460-2075
VL  - 35
SP  - 162
EP  - 175
PB  - Wiley-Blackwell
CY  - Hoboken
ER  -