{"id":{"repo_id":"aachen","oai_identifier":"oai:publications.rwth-aachen.de:50583"},"canonical_url":"https://search.dev.ndltd.org/etd/aachen/oai:publications.rwth-aachen.de:50583","repository":{"repo_id":"aachen","name":"RWTH Aachen University","base_url":"https://publications.rwth-aachen.de/oai2d"},"display":{"title":"Die C 4 -spezifische Phosphoenolpyruvatcarboxylase in Zea mays L.: Modellsystem zur Signaintegration auf Chromatinebene in Pflanzen","abstract":"Multiple internal and external stimuli act on the transcriptional activity of the C4-specific isoform of phosphoenolpyruvate carboxylase (C4-Pepc) and have to be integrated into a single promoter response. Therefore, C4-Pepc is a perfect candidate to investigate signal integration on the chromatin level. Previous studies in our group already revealed a model for this process: The promoter region of C4-Pepc can be divided into a distal and a proximal region. The level of histone acetylation at the distal promoter correlates with promoter activity. This is regardless of whether promoter activity is regulated by light, nitrogen depletion or sugar availability. Some of these modifications are regulated by modulation of histone acetyltransferase (HAT) activity whereas for others histone deacetylases (HDAC) activity is modulated. In contrast, at the proximal core promoter most acetylations are constitutively present. Only two specific lysine residues (H4K5 and H3K9) are acetylated after illumination and this process is independent of promoter activity. These results led to the conclusion that illumination is necessary and sufficient to manifest these specific modifications on the core promoter. In this study, the daily rhythm of histone modifications and promoter activity were analyzed. In the second half of the day, light-induced core promoter modifications are completely removed although plants are fully illuminated. By application of a histone deacetylase inhibitor it became evident that up-regulation of HDAC was responsible for removal of the modification. This extends the current model by a diurnal controlled signal integrator upstream of HDAC-activity. Continuous light experiments were used to analyze circadian control of promoter activity. Indeed, promoter activity was diurnally regulated even under these conditions. However, histone acetylation did not correlate in all promoter regions with this observation. Importantly, H3K9 in the core promoter region and H4K5 in nearly all promoter regions did not follow the diurnal rhythm but remained low after two or one days of constant light. This indicates that histone acetylation in the core promoter region is not necessary for circadian regulation of C4-Pepc. Two additional modification sites showing light-induced acetylation in the distal (H3K23 and H3K27) and the proximal (H3K23 only) promoter region were identified. The analysis was extended to C4-Pyruvate-Pi-Dikinase (C4-Ppdk) and C4-Malic enzyme (C4-Me). As shown for C4-Pepc, individual histone acetylations were induced by light whereas most others were present constitutively. Also here, complete promoter deacetylation during the light period was observed. Promoter activity showed completely different diurnal rhythms compared to C4-Pepc. However, in constant light, both genes adopted the typical rhythm observed for C4-Pepc. This points to an independent control of diurnal and circadian regulation. In addition, 23 maize genes showing similar gene regulation by light, sugar availability, and nitrogen depletion compared to C4-Pepc were identified using microarray technology. Chromatin analysis of the corresponding promoters will reveal whether the model for signal integration on the C4-Pepc gene can be generalized or at least extended to other genes.","abstract_html":"Multiple internal and external stimuli act on the transcriptional activity of the C4-specific isoform of phosphoenolpyruvate carboxylase (C4-Pepc) and have to be integrated into a single promoter response. Therefore, C4-Pepc is a perfect candidate to investigate signal integration on the chromatin level. Previous studies in our group already revealed a model for this process: The promoter region of C4-Pepc can be divided into a distal and a proximal region. The level of histone acetylation at the distal promoter correlates with promoter activity. This is regardless of whether promoter activity is regulated by light, nitrogen depletion or sugar availability. Some of these modifications are regulated by modulation of histone acetyltransferase (HAT) activity whereas for others histone deacetylases (HDAC) activity is modulated. In contrast, at the proximal core promoter most acetylations are constitutively present. Only two specific lysine residues (H4K5 and H3K9) are acetylated after illumination and this process is independent of promoter activity. These results led to the conclusion that illumination is necessary and sufficient to manifest these specific modifications on the core promoter. In this study, the daily rhythm of histone modifications and promoter activity were analyzed. In the second half of the day, light-induced core promoter modifications are completely removed although plants are fully illuminated. By application of a histone deacetylase inhibitor it became evident that up-regulation of HDAC was responsible for removal of the modification. This extends the current model by a diurnal controlled signal integrator upstream of HDAC-activity. Continuous light experiments were used to analyze circadian control of promoter activity. Indeed, promoter activity was diurnally regulated even under these conditions. However, histone acetylation did not correlate in all promoter regions with this observation. Importantly, H3K9 in the core promoter region and H4K5 in nearly all promoter regions did not follow the diurnal rhythm but remained low after two or one days of constant light. This indicates that histone acetylation in the core promoter region is not necessary for circadian regulation of C4-Pepc. Two additional modification sites showing light-induced acetylation in the distal (H3K23 and H3K27) and the proximal (H3K23 only) promoter region were identified. The analysis was extended to C4-Pyruvate-Pi-Dikinase (C4-Ppdk) and C4-Malic enzyme (C4-Me). As shown for C4-Pepc, individual histone acetylations were induced by light whereas most others were present constitutively. Also here, complete promoter deacetylation during the light period was observed. Promoter activity showed completely different diurnal rhythms compared to C4-Pepc. However, in constant light, both genes adopted the typical rhythm observed for C4-Pepc. This points to an independent control of diurnal and circadian regulation. In addition, 23 maize genes showing similar gene regulation by light, sugar availability, and nitrogen depletion compared to C4-Pepc were identified using microarray technology. Chromatin analysis of the corresponding promoters will reveal whether the model for signal integration on the C4-Pepc gene can be generalized or at least extended to other genes.","abstract_has_math":false,"creators":["Horst, Ina"],"institution":"Publikationsserver der RWTH Aachen University","degree_name":null,"degree_level":null,"degree_discipline":null,"degree_department":null,"school":null,"contributors":["Peterhänsel, Christoph"],"advisors":[],"committee_chairs":[],"committee_members":[],"year":2009,"date_issued":"2009","date_published":"2009","updated_at":"2026-07-30T19:40:25Z","subjects":["info:eu-repo/classification/ddc/570","Epigenetik","Transkription <Genetik>","Histon-Acetyltransferase","Histon-Deacetylase","Mais","C4-Pflanzen","Phosphoenolpyruvatcarboxylase","Biowissenschaften, Biologie","epigenetic","histone acetylation","transcription","C4-Pepc","maize"],"languages":["ger"],"rights":["info:eu-repo/semantics/openAccess"],"rights_urls":[],"identifier_entries":[{"key":"dc:identifier","label":"Identifier","values":["https://publications.rwth-aachen.de/search?p=id:%22RWTH-CONV-113123%22"],"render_values":[{"text":"https://publications.rwth-aachen.de/search?p=id:%22RWTH-CONV-113123%22","href":"https://publications.rwth-aachen.de/search?p=id:%22RWTH-CONV-113123%22","code":true}]}]},"links":{"outbound_url":"https://publications.rwth-aachen.de/record/50583","outbound_label":"Repository record","outbound_source":"dc:identifier"},"source_record":{"url":"https://publications.rwth-aachen.de/oai2d?verb=GetRecord&metadataPrefix=oai_dc&identifier=oai%3Apublications.rwth-aachen.de%3A50583","prefix":"oai_dc"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor","label":"Contributor","values":["Peterhänsel, Christoph"]},{"key":"dc:creator","label":"Author","values":["Horst, Ina"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:coverage","label":"Dc Coverage","values":["DE"]},{"key":"dc:date","label":"Dc Date","values":["2009"]},{"key":"dc:publisher","label":"Institution","values":["Publikationsserver der RWTH Aachen University"]},{"key":"dc:relation","label":"Dc Relation","values":["info:eu-repo/semantics/altIdentifier/urn/urn:nbn:de:hbz:82-opus-26780"]},{"key":"dc:type","label":"Dc Type","values":["info:eu-repo/semantics/doctoralThesis","info:eu-repo/semantics/publishedVersion"]}]},{"id":"subjects_keywords","label":"Subjects and Keywords","entries":[{"key":"dc:subject","label":"Dc Subject","values":["info:eu-repo/classification/ddc/570","Epigenetik","Transkription <Genetik>","Histon-Acetyltransferase","Histon-Deacetylase","Mais","C4-Pflanzen","Phosphoenolpyruvatcarboxylase","Biowissenschaften, Biologie","epigenetic","histone acetylation","transcription","C4-Pepc","maize"]}]},{"id":"language_rights","label":"Language and Rights","entries":[{"key":"dc:language","label":"Dc Language","values":["ger"]},{"key":"dc:rights","label":"Dc Rights","values":["info:eu-repo/semantics/openAccess"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier","label":"Identifier","values":["https://publications.rwth-aachen.de/record/50583","https://publications.rwth-aachen.de/search?p=id:%22RWTH-CONV-113123%22"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description","label":"Description","values":["Multiple internal and external stimuli act on the transcriptional activity of the C4-specific isoform of phosphoenolpyruvate carboxylase (C4-Pepc) and have to be integrated into a single promoter response. Therefore, C4-Pepc is a perfect candidate to investigate signal integration on the chromatin level. Previous studies in our group already revealed a model for this process: The promoter region of C4-Pepc can be divided into a distal and a proximal region. The level of histone acetylation at the distal promoter correlates with promoter activity. This is regardless of whether promoter activity is regulated by light, nitrogen depletion or sugar availability. Some of these modifications are regulated by modulation of histone acetyltransferase (HAT) activity whereas for others histone deacetylases (HDAC) activity is modulated. In contrast, at the proximal core promoter most acetylations are constitutively present. Only two specific lysine residues (H4K5 and H3K9) are acetylated after illumination and this process is independent of promoter activity. These results led to the conclusion that illumination is necessary and sufficient to manifest these specific modifications on the core promoter. In this study, the daily rhythm of histone modifications and promoter activity were analyzed. In the second half of the day, light-induced core promoter modifications are completely removed although plants are fully illuminated. By application of a histone deacetylase inhibitor it became evident that up-regulation of HDAC was responsible for removal of the modification. This extends the current model by a diurnal controlled signal integrator upstream of HDAC-activity. Continuous light experiments were used to analyze circadian control of promoter activity. Indeed, promoter activity was diurnally regulated even under these conditions. However, histone acetylation did not correlate in all promoter regions with this observation. Importantly, H3K9 in the core promoter region and H4K5 in nearly all promoter regions did not follow the diurnal rhythm but remained low after two or one days of constant light. This indicates that histone acetylation in the core promoter region is not necessary for circadian regulation of C4-Pepc. Two additional modification sites showing light-induced acetylation in the distal (H3K23 and H3K27) and the proximal (H3K23 only) promoter region were identified. The analysis was extended to C4-Pyruvate-Pi-Dikinase (C4-Ppdk) and C4-Malic enzyme (C4-Me). As shown for C4-Pepc, individual histone acetylations were induced by light whereas most others were present constitutively. Also here, complete promoter deacetylation during the light period was observed. Promoter activity showed completely different diurnal rhythms compared to C4-Pepc. However, in constant light, both genes adopted the typical rhythm observed for C4-Pepc. This points to an independent control of diurnal and circadian regulation. In addition, 23 maize genes showing similar gene regulation by light, sugar availability, and nitrogen depletion compared to C4-Pepc were identified using microarray technology. Chromatin analysis of the corresponding promoters will reveal whether the model for signal integration on the C4-Pepc gene can be generalized or at least extended to other genes."]},{"key":"dc:source","label":"Dc Source","values":["Aachen : Publikationsserver der RWTH Aachen University III, 140 Bl. : graph. Darst. (2009). = Aachen, Techn. Hochsch., Diss., 2009"]},{"key":"dc:title","label":"Title","values":["Die C 4 -spezifische Phosphoenolpyruvatcarboxylase in Zea mays L.: Modellsystem zur Signaintegration auf Chromatinebene in Pflanzen"]}]}],"canonical_facts":{"dc:contributor":["Peterhänsel, Christoph"],"dc:coverage":["DE"],"dc:creator":["Horst, Ina"],"dc:date":["2009"],"dc:description":["Multiple internal and external stimuli act on the transcriptional activity of the C4-specific isoform of phosphoenolpyruvate carboxylase (C4-Pepc) and have to be integrated into a single promoter response. Therefore, C4-Pepc is a perfect candidate to investigate signal integration on the chromatin level. Previous studies in our group already revealed a model for this process: The promoter region of C4-Pepc can be divided into a distal and a proximal region. The level of histone acetylation at the distal promoter correlates with promoter activity. This is regardless of whether promoter activity is regulated by light, nitrogen depletion or sugar availability. Some of these modifications are regulated by modulation of histone acetyltransferase (HAT) activity whereas for others histone deacetylases (HDAC) activity is modulated. In contrast, at the proximal core promoter most acetylations are constitutively present. Only two specific lysine residues (H4K5 and H3K9) are acetylated after illumination and this process is independent of promoter activity. These results led to the conclusion that illumination is necessary and sufficient to manifest these specific modifications on the core promoter. In this study, the daily rhythm of histone modifications and promoter activity were analyzed. In the second half of the day, light-induced core promoter modifications are completely removed although plants are fully illuminated. By application of a histone deacetylase inhibitor it became evident that up-regulation of HDAC was responsible for removal of the modification. This extends the current model by a diurnal controlled signal integrator upstream of HDAC-activity. Continuous light experiments were used to analyze circadian control of promoter activity. Indeed, promoter activity was diurnally regulated even under these conditions. However, histone acetylation did not correlate in all promoter regions with this observation. Importantly, H3K9 in the core promoter region and H4K5 in nearly all promoter regions did not follow the diurnal rhythm but remained low after two or one days of constant light. This indicates that histone acetylation in the core promoter region is not necessary for circadian regulation of C4-Pepc. Two additional modification sites showing light-induced acetylation in the distal (H3K23 and H3K27) and the proximal (H3K23 only) promoter region were identified. The analysis was extended to C4-Pyruvate-Pi-Dikinase (C4-Ppdk) and C4-Malic enzyme (C4-Me). As shown for C4-Pepc, individual histone acetylations were induced by light whereas most others were present constitutively. Also here, complete promoter deacetylation during the light period was observed. Promoter activity showed completely different diurnal rhythms compared to C4-Pepc. However, in constant light, both genes adopted the typical rhythm observed for C4-Pepc. This points to an independent control of diurnal and circadian regulation. In addition, 23 maize genes showing similar gene regulation by light, sugar availability, and nitrogen depletion compared to C4-Pepc were identified using microarray technology. Chromatin analysis of the corresponding promoters will reveal whether the model for signal integration on the C4-Pepc gene can be generalized or at least extended to other genes."],"dc:identifier":["https://publications.rwth-aachen.de/record/50583","https://publications.rwth-aachen.de/search?p=id:%22RWTH-CONV-113123%22"],"dc:language":["ger"],"dc:publisher":["Publikationsserver der RWTH Aachen University"],"dc:relation":["info:eu-repo/semantics/altIdentifier/urn/urn:nbn:de:hbz:82-opus-26780"],"dc:rights":["info:eu-repo/semantics/openAccess"],"dc:source":["Aachen : Publikationsserver der RWTH Aachen University III, 140 Bl. : graph. Darst. (2009). = Aachen, Techn. 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