H2A.Z - Containing Nucleosomes Mediate the Thermosensory Response in Arabidopsis
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ABSTRACT:
ORGANISM(S): Arabidopsis thaliana
PROVIDER: GSE18624 | GEO | 2010/01/08
SECONDARY ACCESSION(S): PRJNA121461
REPOSITORIES: GEO
Similar Datasets
Project description:We isolated mutants in Arabidopsis with enhanced ambient temperature response. Microarray analysis was performed to understand the extent to which ambient temperature transcriptome is perturbed in the mutants in comparison with the WT at non inductive 12 ºC and after shift to inductive 27 ºC for 2 h and 24 h. We performed global transcript profiling to understand the regulation of of gene expression underlying ambient temperature response. Sterilized wild type Arabidopsis Col-0 as well as the arp6-10 mutant seeds were plated on half-strength MS plates without sugar. Plates were incubated at 4 ºC in dark for 48 hours before transfering to 20 ºC with light. 5 day old seedlings were transfered to 12 ºC incubaor with continuous light for 3 days befroe shifting to 27 ºC. Samples (Whole seedlings) were collected before shifting (0 h) and 2 h and 24 h after shifting to 27 ºC by immediately freezing in liquid nitrogen.
2010-01-08 | E-GEOD-18624 | biostudies-arrayexpress
Project description:H2A.Z is incorporated into nucleosomes located around transcription start sites and functions as an epigenetic regulator for the transcription of certain genes. During transcriptional regulation, the heterotypic H2A.Z/H2A nucleosome containing one each of H2A.Z and H2A is formed. However, previous homotypic H2A.Z nucleosome structures suggested that the L1 loop region of H2A.Z would sterically clash with the corresponding region of canonical H2A in the heterotypic nucleosome. To resolve this issue, we determined the crystal structures of heterotypic H2A.Z/H2A nucleosomes. In the H2A.Z/H2A nucleosome structure, the H2A.Z L1 loop structure was drastically altered without any structural changes of the canonical H2A L1 loop, thus avoiding the steric clash. Unexpectedly, the heterotypic H2A.Z/H2A nucleosome is more stable than the homotypic H2A.Z nucleosome. These data suggested that the flexible character of the H2A.Z L1 loop plays an essential role in forming the stable heterotypic H2A.Z/H2A nucleosome.
| S-EPMC4929947 | biostudies-literature
Project description:Microarray analysis on Brachypodium distachyon seedlings was performed to determine the response of the transcriptome to changes in ambient temperature, including identification of marker genes that were up-regulated or down-regulated by a moderate increase in growth temperature. Wild-type Brachypodium (Bd21) seedlings were grown on MSR63 media without sucrose (Alves et al. 2009 Nature Protocols vol. 4 pp 638-649) in a short-day photoperiod (14 hr light/ 10 hr dark) at 17 ºC. As the third leaf was emerging, plants were transferred to 12 ºC for 48 hrs. Plants were then maintained at 12 ºC or transferred to one of two temperature treatments: constant 22 ºC or constant 27 ºC. Samples were collected before the shift (0 hr) and at 2 hr and 24 hr after the shift and immediately frozen in liquid nitrogen. For each harvest, two to three replicates were collected that each contained 3 seedlings.
2013-06-07 | E-MEXP-3918 | biostudies-arrayexpress
Project description:Plants are sessile organisms and therefore must sense and respond to changes of their surrounding conditions such as ambient temperature, which vary diurnally and seasonally. It is not yet clear how plants sense temperature and integrate this information into their development. We have previously shown that H2A.Z-nucleosomes are evicted in response to warmer temperatures. It is not clear however, whether the link between transcriptional responsiveness and changes in H2A.Z binding in context of temperature shifts is a global trend that can be seen throughout the genome, or the phenomenon is specific to a specialised set of temperature-responsive genes. In addition to the role of H2A.Z-nucleosome dynamics in the transcriptional response to temperature, it was shown that genes strongly misregulated in the h2a.z mutant are enriched for gene categories involved in response to multiple environmental cues. This suggests that H2A.Z could be implicated in the transcriptional response to various environmental inputs, raising the question: What brings the specificity of H2A.Z dynamics in response to temperature? To address this question we have profiled H2A.Z-nucleosome occupancy genome wide (using ChIP-seq) during a time course after temperature variation and compared its dynamics to transcriptional changes. We identified a fast, targeted and transient eviction of H2A.Z associated with transcriptional activation in response to temperature for a few hundreds genes. This eviction is associated with a reduction of the stability of the nucleosome. Moreover the genes with a fast H2A.Z eviction were strongly enriched in heat shock elements in their promoter and we observed a strong association between HSF1 binding and H2AZ eviction at warm temperature. These results highlight the importance of the interplay between transcription factors and chromatin to allow a controlled and dynamics response to temperature.
2017-09-29 | GSE102898 | GEO
Project description:Plants are sessile organisms and therefore must sense and respond to changes of their surrounding conditions such as ambient temperature, which vary diurnally and seasonally. It is not yet clear how plants sense temperature and integrate this information into their development. We have previously shown that H2A.Z-nucleosomes are evicted in response to warmer temperatures. It is not clear however, whether the link between transcriptional responsiveness and changes in H2A.Z binding in context of temperature shifts is a global trend that can be seen throughout the genome, or the phenomenon is specific to a specialised set of temperature-responsive genes. In addition to the role of H2A.Z-nucleosome dynamics in the transcriptional response to temperature, it was shown that genes strongly misregulated in the h2a.z mutant are enriched for gene categories involved in response to multiple environmental cues. This suggests that H2A.Z could be implicated in the transcriptional response to various environmental inputs, raising the question: What brings the specificity of H2A.Z dynamics in response to temperature? To address this question we have profiled H2A.Z-nucleosome occupancy genome wide (using ChIP-seq) during a time course after temperature variation and compared its dynamics to transcriptional changes. We identified a fast, targeted and transient eviction of H2A.Z associated with transcriptional activation in response to temperature for a few hundreds genes. This eviction is associated with a reduction of the stability of the nucleosome. Moreover the genes with a fast H2A.Z eviction were strongly enriched in heat shock elements in their promoter and we observed a strong association between HSF1 binding and H2AZ eviction at warm temperature. These results highlight the importance of the interplay between transcription factors and chromatin to allow a controlled and dynamics response to temperature.
2017-09-29 | GSE94900 | GEO
Project description:Plants are sessile organisms and therefore must sense and respond to changes of their surrounding conditions such as ambient temperature, which vary diurnally and seasonally. It is not yet clear how plants sense temperature and integrate this information into their development. We have previously shown that H2A.Z-nucleosomes are evicted in response to warmer temperatures. It is not clear however, whether the link between transcriptional responsiveness and changes in H2A.Z binding in context of temperature shifts is a global trend that can be seen throughout the genome, or the phenomenon is specific to a specialised set of temperature-responsive genes. In addition to the role of H2A.Z-nucleosome dynamics in the transcriptional response to temperature, it was shown that genes strongly misregulated in the h2a.z mutant are enriched for gene categories involved in response to multiple environmental cues. This suggests that H2A.Z could be implicated in the transcriptional response to various environmental inputs, raising the question: What brings the specificity of H2A.Z dynamics in response to temperature? To address this question we have profiled H2A.Z-nucleosome occupancy genome wide (using ChIP-seq) during a time course after temperature variation and compared its dynamics to transcriptional changes. We identified a fast, targeted and transient eviction of H2A.Z associated with transcriptional activation in response to temperature for a few hundreds genes. This eviction is associated with a reduction of the stability of the nucleosome. Moreover the genes with a fast H2A.Z eviction were strongly enriched in heat shock elements in their promoter and we observed a strong association between HSF1 binding and H2AZ eviction at warm temperature. These results highlight the importance of the interplay between transcription factors and chromatin to allow a controlled and dynamics response to temperature.
2017-09-29 | GSE79353 | GEO
Project description:Plants are sessile organisms and therefore must sense and respond to changes of their surrounding conditions such as ambient temperature, which vary diurnally and seasonally. It is not yet clear how plants sense temperature and integrate this information into their development. We have previously shown that H2A.Z-nucleosomes are evicted in response to warmer temperatures. It is not clear however, whether the link between transcriptional responsiveness and changes in H2A.Z binding in context of temperature shifts is a global trend that can be seen throughout the genome, or the phenomenon is specific to a specialised set of temperature-responsive genes. In addition to the role of H2A.Z-nucleosome dynamics in the transcriptional response to temperature, it was shown that genes strongly misregulated in the h2a.z mutant are enriched for gene categories involved in response to multiple environmental cues. This suggests that H2A.Z could be implicated in the transcriptional response to various environmental inputs, raising the question: What brings the specificity of H2A.Z dynamics in response to temperature? To address this question we have profiled H2A.Z-nucleosome occupancy genome wide (using ChIP-seq) during a time course after temperature variation and compared its dynamics to transcriptional changes. We identified a fast, targeted and transient eviction of H2A.Z associated with transcriptional activation in response to temperature for a few hundreds genes. This eviction is associated with a reduction of the stability of the nucleosome. Moreover the genes with a fast H2A.Z eviction were strongly enriched in heat shock elements in their promoter and we observed a strong association between HSF1 binding and H2AZ eviction at warm temperature. These results highlight the importance of the interplay between transcription factors and chromatin to allow a controlled and dynamics response to temperature.
2017-09-29 | GSE79354 | GEO
Project description:The rationale: Activation of the immune response antagonizes plant growth and development in absence of pathogen, and such autoimmune phenotype is often suppressed by the elevation of ambient temperature. However, the molecular regulation of ambient temperature-sensitive intersection of immune response and growth is largely elusive. Methods: A genetic screen identified an Arabidopsis mutant, zed1-D, by its high temperature-dependent growth retardation. A combination of molecular, cytological and genetic approaches was used to investigate the molecular basis behind the temperature-sensitive growth and immune response in zed1-D. Key results: A dominant mutation in HOPZ-ETI-DEFICIENT 1 (ZED1) is responsible for a high temperature-dependent autoimmunity and growth retardation in the zed1-D. The autoimmune phenotype in the zed1-D is dependent on the HOPZ-ACTIVATED RESISTANCE 1 (ZAR1). ZED1 and some ZED1-related kinases (ZRKs) are induced by elevated temperature and function cooperatively to suppress the immune response by modulating the transcription of SUPPRESSOR OF NPR1-1 CONSTITUTIVE 1 (SNC1) in absence of pathogen. Main conclusion: Our data reveal a previously unidentified role of ZRKs in ambient temperature-sensitive immune response in absence of pathogen, and thus disclose a possible molecular mechanism underlying temperature-mediated intersection of immune response and growth in plants.
2018-03-26 | GSE95665 | GEO
Project description:To understand how chromatin structure is organized by different histone variants, we have measured the genome-wide distribution of nucleosome core particles (NCPs) containing the histone variants H3.3 and H2A.Z in human cells. We find that a special class of NCPs containing both variants is enriched at 'nucleosome-free regions' of active promoters, enhancers and insulator regions. We show that preparative methods used previously in studying nucleosome structure result in the loss of these unstable double-variant NCPs. It seems likely that this instability facilitates the access of transcription factors to promoters and other regulatory sites in vivo. Other combinations of variants have different distributions, consistent with distinct roles for histone variants in the modulation of gene expression.
| S-EPMC3125718 | biostudies-literature
Project description:Nucleosomes that contain the histone variant H2A.Z are enriched around transcriptional start sites, but the mechanistic basis for this enrichment is unknown. A single octameric nucleosome can contain two H2A.Z histones (homotypic) or one H2A.Z and one canonical H2A (heterotypic). To elucidate the function of H2A.Z, we generated high-resolution maps of homotypic and heterotypic Drosophila H2A.Z (H2Av) nucleosomes. Although homotypic and heterotypic H2A.Z nucleosomes mapped throughout most of the genome, homotypic nucleosomes were enriched and heterotypic nucleosomes were depleted downstream of active promoters and intron-exon junctions. The distribution of homotypic H2A.Z nucleosomes resembled that of classical active chromatin and showed evidence of disruption during transcriptional elongation. Both homotypic H2A.Z nucleosomes and classical active chromatin were depleted downstream of paused polymerases. Our results suggest that H2A.Z enrichment patterns result from intrinsic structural differences between heterotypic and homotypic H2A.Z nucleosomes that follow disruption during transcriptional elongation.
| S-EPMC3051840 | biostudies-literature