Differential usage of shared binding sites drives functional specialization of an essential family of transcription factors [ChIP-seq]
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ABSTRACT:
ORGANISM(S): Arabidopsis thaliana
PROVIDER: GSE253671 | GEO | 2024/10/08
REPOSITORIES: GEO
Similar Datasets
Project description:Throughout evolution, the duplication and functional divergence of transcription factors (TFs) has driven cellular and organismal complexity. Mechanisms by which paralogous TFs functionally diverge are thus of broad interest yet remain poorly understood. One well-established mechanism underlying TF divergence is the occupation and regulation of distinct sets of genes. Here we test for new mechanisms using CORONA (CNA) and PHABULOSA (PHB), two representative members of the CLASS III HOMEODOMAIN LEUCINE ZIPPER (HD-ZIPIII) family of plant TFs. CNA and PHB have largely overlapping binding profiles yet each paralog has hundreds of uniquely regulated targets. Regulation of a given gene thus depends on whether its local binding site is considered primed (inactive) or regulated (active) by CNA or PHB. This decision appears to be controlled, at least in part, by their lipid binding START domain, proposing a model in which HD-ZIPIII TFs use information integrated by their START domain to generate paralog-specific transcriptional outcomes at commonly bound genes. Taken together, our study identifies a new mechanism of TF paralog divergence and proposes the ubiquitously distributed START evolutionary module as a driver of functional divergence.
2024-10-08 | GSE253674 | GEO
Project description:The class III HD-ZIP transcription factors regulate vascular patterning in Arabidopsis thaliana roots. In this expression study we compare the expression profile of the cna-2 phb-13 phv-11 and cna-2 phb-13 phv-11 rev-6 mutants to their wild type. The results are presented in PHABULOSA mediates an auxin signaling loop to regulate vascular patterning in Arabidopsis by Christina Joy Müller, Ana Elisa Valdés, Guodong Wang, Prashanth Ramachandran, Lisa Beste, Daniel Uddenberg, and Annelie Carlsbecker, accepted for publication in Plant Physiology Nov. 2015. Plant vascular tissues, xylem and phloem, differentiate in distinct patterns from procambial cells as an integral transport system for water, sugars and signaling molecules. Procambium formation is promoted by high auxin levels activating class III homeodomain leucine zipper (HD-ZIP III) transcription factors (TFs). In the root of Arabidopsis thaliana, HD-ZIP III TFs dose-dependently govern the patterning of the xylem axis, with higher levels promoting metaxylem cell identity in the central axis and lower levels protoxylem at its flanks. It is, however, unclear by what mechanisms the HD-ZIP III TFs control xylem axis patterning. Here we present data suggesting that an important mechanism is their ability to moderate auxin response. We found that changes in HD-ZIP III TF levels affect the expression of genes encoding core auxin response molecules. We show that one of the HD-ZIP III TFs, PHABULOSA, directly binds the promoter of both MONOPTEROS/AUXIN RESPONSE FACTOR5 (MP/ARF5), a key factor in vascular formation, and IAA20, encoding an AUX/IAA protein which is stable in the presence of auxin and able to interact with and repress MP activity. The double mutant of IAA20 and its closest homologue IAA30 forms ectopic protoxylem, while overexpression of IAA30 causes discontinuous protoxylem and occasional ectopic metaxylem, similar to a weak loss-of-function mp-mutant. Our results provide evidence that HD-ZIP III TFs directly affect auxin response and mediate a feed forward loop formed by MP and IAA20 that may focus and stabilize auxin response during vascular patterning and differentiation of xylem cell types.
2015-12-03 | GSE75610 | GEO
Project description:The class III HD-ZIP transcription factors regulate vascular patterning in Arabidopsis thaliana roots. In this expression study we compare the expression profile of the athb8 cna phb phv quadruple mutant to its wild type. The results are presented in PHABULOSA mediates an auxin signaling loop to regulate vascular patterning in Arabidopsis by Christina Joy Müller, Ana Elisa Valdés, Guodong Wang, Prashanth Ramachandran, Lisa Beste, Daniel Uddenberg, and Annelie Carlsbecker, accepted for publication in Plant Physiology Nov. 2015. Plant vascular tissues, xylem and phloem, differentiate in distinct patterns from procambial cells as an integral transport system for water, sugars and signaling molecules. Procambium formation is promoted by high auxin levels activating class III homeodomain leucine zipper (HD-ZIP III) transcription factors (TFs). In the root of Arabidopsis thaliana, HD-ZIP III TFs dose-dependently govern the patterning of the xylem axis, with higher levels promoting metaxylem cell identity in the central axis and lower levels protoxylem at its flanks. It is, however, unclear by what mechanisms the HD-ZIP III TFs control xylem axis patterning. Here we present data suggesting that an important mechanism is their ability to moderate auxin response. We found that changes in HD-ZIP III TF levels affect the expression of genes encoding core auxin response molecules. We show that one of the HD-ZIP III TFs, PHABULOSA, directly binds the promoter of both MONOPTEROS/AUXIN RESPONSE FACTOR5 (MP/ARF5), a key factor in vascular formation, and IAA20, encoding an AUX/IAA protein which is stable in the presence of auxin and able to interact with and repress MP activity. The double mutant of IAA20 and its closest homologue IAA30 forms ectopic protoxylem, while overexpression of IAA30 causes discontinuous protoxylem and occasional ectopic metaxylem, similar to a weak loss-of-function mp-mutant. Our results provide evidence that HD-ZIP III TFs directly affect auxin response and mediate a feed forward loop formed by MP and IAA20 that may focus and stabilize auxin response during vascular patterning and differentiation of xylem cell types.
2015-12-03 | GSE75611 | GEO
Project description:The establishment of ad/abaxial polarity is a fundamental event in plant development. It is critical for correct polar development of the leaf (the upper portion of the leaf is chloroplast rich and optimized for light capture while the lower portion is optimized for gas exchange) and for creating an environment that allows the formation of new meristems (centers of stem cell growth). Class III homeodomain-leucine zipper (HD-ZIPIII) proteins are conserved plant proteins that act as potent regulators of ad/abaxial polarity. HD-ZIPIII protein activity promotes the development of upper (adaxial) leaf fates and meristem formation; in its absence lower (abaxial) leaf fates develop and meristems fail to form. A network of regulatory factors controls the establishment of ad/abaxial leaf fates. However, this network is incomplete and how these factors control one another is poorly understood. Here we report a new family of plant genes, the LITTLE ZIPPER (ZPR) genes (consisting principally of a stretch of leucine zipper similar to the leucine zipper in HD-ZIPIII proteins) that are transcriptionally up-regulated by HD-ZIPIII activity. Furthermore, we show that the ZPR proteins interact with and repress HD-ZIPIII activity, thus forming a negative feedback loop. Our results suggest that HD-ZIPIII proteins exist in active homodimers and, together with the ZPR proteins, in inactive heterodimers. The newly discovered HD-ZIPIII/ZPR regulatory module would not only serve to dampen the effect of fluctuations in HD-ZIPIII protein levels but more importantly would provide a point of regulation - control over the ratio of inactive heterodimers to active homodimers - that could be influenced by other components of the pathway. For instance, the binding of a small hydrophobic molecule to the conserved (yet little understood) START domain present in the HD-ZIPIII proteins may influence the type of dimer formed. Published in: Wenkel, S., Emery, J., Hou, B.-H., Evans, M.M.S. and M.K. Barton, 2007, A Feedback Regulatory Module Formed by LITTLE ZIPPER and HD-ZIPIII Genes. Plant Cell 2007 Keywords: screen for downstream genes, transcription factor induction
2007-12-05 | GSE7003 | GEO
Project description:The establishment of ad/abaxial polarity is a fundamental event in plant development. It is critical for correct polar development of the leaf (the upper portion of the leaf is chloroplast rich and optimized for light capture while the lower portion is optimized for gas exchange) and for creating an environment that allows the formation of new meristems (centers of stem cell growth). Class III homeodomain-leucine zipper (HD-ZIPIII) proteins are conserved plant proteins that act as potent regulators of ad/abaxial polarity. HD-ZIPIII protein activity promotes the development of upper (adaxial) leaf fates and meristem formation; in its absence lower (abaxial) leaf fates develop and meristems fail to form. A network of regulatory factors controls the establishment of ad/abaxial leaf fates. However, this network is incomplete and how these factors control one another is poorly understood. Here we report a new family of plant genes, the LITTLE ZIPPER (ZPR) genes (consisting principally of a stretch of leucine zipper similar to the leucine zipper in HD-ZIPIII proteins) that are transcriptionally up-regulated by HD-ZIPIII activity. Furthermore, we show that the ZPR proteins interact with and repress HD-ZIPIII activity, thus forming a negative feedback loop. Our results suggest that HD-ZIPIII proteins exist in active homodimers and, together with the ZPR proteins, in inactive heterodimers. The newly discovered HD-ZIPIII/ZPR regulatory module would not only serve to dampen the effect of fluctuations in HD-ZIPIII protein levels but more importantly would provide a point of regulation - control over the ratio of inactive heterodimers to active homodimers - that could be influenced by other components of the pathway. For instance, the binding of a small hydrophobic molecule to the conserved (yet little understood) START domain present in the HD-ZIPIII proteins may influence the type of dimer formed. Published in:; Wenkel, S., Emery, J., Hou, B.-H., Evans, M.M.S. and M.K. Barton, 2007, A Feedback Regulatory Module Formed by LITTLE ZIPPER and HD-ZIPIII Genes. Plant Cell 2007 Experiment Overall Design: One of the five Arabidopsis HD-ZIPIII proteins, REVOLUTA, was placed under glucocorticoid control by fusing the glucocorticoid receptor (GR) domain to its amino terminus. This gene fusion was placed under the control of the highly and constitutively expressed viral CaMV35S promoter. Since the HD-ZIPIII genes are controlled by microRNAs, it was also necessary to introduce mutations that disrupted the microRNA complementary sequence. Transgenic Arabidopsis seedlings carrying this construct (GR-REV) as well as wild-type seedlings were grown in liquid culture for ten days. At this point, one flask each of wt and transgenic seedlings was treated with carrier alone (ethanol) and one flask each of wt and transgenic seedlings was treated with dexamethasone. RNA was harvested from these samples after one hour, labeled and hybridized to Affymetrix microarrays.
2008-06-15 | E-GEOD-7003 | biostudies-arrayexpress
Project description:We report the discovery of a root growth program in Arabidopsis that is independent of a functional quiescent center (QC). In this regulatory program, PHABULOSA (PHB), posttranscriptionally regulated by SHR and SCR, plays a central role. In phb shr and phb scr mutants, root meristem/growth activity recovers significantly. Interestingly, this recovery does not accompany the resurgence of QC cells. PHB regulates apical root growth in stele cells of the root meristem, located proximal to the QC. Our genome-wide investigation suggests that PHB exerts its influence on root growth by regulating auxin-cytokinin homeostasis. Apical root growth was restored when cytokinin levels were genetically reduced in the shr mutant. Conversely, when miRNA-resistant PHB was expressed in the root stele cells, apical root growth and meristem functions were significantly inhibited without blocking the QC identity. Taken together, our investigation reveals two mechanisms through which SHR regulates root growth and stem cell activities: one is to specify and maintain the QC and the other is to regulate the proximal meristem activity through PHB and cytokinin. In this regulation, QC seems to be more involved in maintaining the M-bM-^@M-^\growth signalM-bM-^@M-^] and thus ensure the indeterminate root growth. Total 7 samples (2 replicates of shr-2 mutant (high PHABULOSA expression) vs. 2 replicates of shr-2 phb-6 (low/absent PHABULOSA expression). 3 replicates of Wild type used as reference sample.
2012-12-31 | E-GEOD-33015 | biostudies-arrayexpress
Project description:The class III HD-ZIPtranscription factors regulate vascular patterning in Arabidopsis thaliana roots. In this expression study we compare the expression profile in root tips upon miR165 induction, after 6h, 10h and 24h. The results are presented in PHABULOSA mediates an auxin signaling loop to regulate vascular patterning in Arabidopsis by Christina Joy Müller, Ana Elisa Valdés, Guodong Wang, Prashanth Ramachandran, Lisa Beste, Daniel Uddenberg, and Annelie Carlsbecker, accepted for publication in Plant Physiology Nov. 2015. Plant vascular tissues, xylem and phloem, differentiate in distinct patterns from procambial cells as an integral transport system for water, sugars and signaling molecules. Procambium formation is promoted by high auxin levels activating class III homeodomain leucine zipper (HD-ZIP III) transcription factors (TFs). In the root of Arabidopsis thaliana, HD-ZIP III TFs dose-dependently govern the patterning of the xylem axis, with higher levels promoting metaxylem cell identity in the central axis and lower levels protoxylem at its flanks. It is, however, unclear by what mechanisms the HD-ZIP III TFs control xylem axis patterning. Here we present data suggesting that an important mechanism is their ability to moderate auxin response. We found that changes in HD-ZIP III TF levels affect the expression of genes encoding core auxin response molecules. We show that one of the HD-ZIP III TFs, PHABULOSA, directly binds the promoter of both MONOPTEROS/AUXIN RESPONSE FACTOR5 (MP/ARF5), a key factor in vascular formation, and IAA20, encoding an AUX/IAA protein which is stable in the presence of auxin and able to interact with and repress MP activity. The double mutant of IAA20 and its closest homologue IAA30 forms ectopic protoxylem, while overexpression of IAA30 causes discontinuous protoxylem and occasional ectopic metaxylem, similar to a weak loss-of-function mp-mutant. Our results provide evidence that HD-ZIP III TFs directly affect auxin response and mediate a feed forward loop formed by MP and IAA20 that may focus and stabilize auxin response during vascular patterning and differentiation of xylem cell types.
2015-12-03 | GSE75609 | GEO
Project description:Unlike the situation in animals, the final morphology of the plant body is highly modulated by the environment. During Arabidopsis development, intrinsic factors provide the framework for basic patterning processes. CLASS III HOMEODOMAIN LEUCINE ZIPPER (HD‐ZIPIII) transcription factors are involved in embryo, shoot and root patterning and during vegetative growth regulate several polarity set‐up processes such as in leaves and the vascular system. Here we show that besides being involved in basic patterning, HD‐ZIPIII transcription factors also have a critical role in controlling elongation growth that is induced when plants experience shade. By using a ChIP‐Seq approach, we have identified several direct target genes of the HD‐ZIPIII transcription factor REVOLUTA (REV). We show that REV acts upstream of auxin biosynthesis and directly regulates several HAT transcription factors that control shade avoidance responses in Arabidopsis. Plants in which HD‐ZIPIII genes are mutated show altered responses to shade revealing that the basic patterning machinery also regulates adaptive development. Thus, HD-ZIPIII transcription factors contribute to shade signaling and act upstream of both auxin and HAT activation.
2012-06-01 | GSE26722 | GEO
Project description:Unlike the situation in animals, the final morphology of the plant body is highly modulated by the environment. During Arabidopsis development, intrinsic factors provide the framework for basic patterning processes. CLASS III HOMEODOMAIN LEUCINE ZIPPER (HD‐ZIPIII) transcription factors are involved in embryo, shoot and root patterning and during vegetative growth regulate several polarity set‐up processes such as in leaves and the vascular system. Here we show that besides being involved in basic patterning, HD‐ZIPIII transcription factors also have a critical role in controlling elongation growth that is induced when plants experience shade. By using a ChIP‐Seq approach, we have identified several direct target genes of the HD‐ZIPIII transcription factor REVOLUTA (REV). We show that REV acts upstream of auxin biosynthesis and directly regulates several HAT transcription factors that control shade avoidance responses in Arabidopsis. Plants in which HD‐ZIPIII genes are mutated show altered responses to shade revealing that the basic patterning machinery also regulates adaptive development. Thus, HD-ZIPIII transcription factors contribute to shade signaling and act upstream of both auxin and HAT activation. A. thaliana REVOLUTA ChIP-seq w control
2012-06-01 | E-GEOD-26722 | biostudies-arrayexpress
Project description:The role of Krüppel-associated box zinc finger proteins (KZFPs), the largest family of repressive transcription factors (TFs) of the human genome, in the pathogenesis of diffuse large B cell lymphoma has not been addressed so far. By correlating the expression of KZFPs with patient outcome, we delineated a subset of 18 co-expressed KZFPs associated to poor prognosis, higher copy number alterations (CNA), and the suppression of hallmarks gene sets linked to immune rejection. Among them, the depletion of the ZNF587-ZNF417 pair of TF paralogs drastically impaired the proliferation of both activated B cell (ABC) and germinal center B (GCB) DLBCL cell lines, by triggering replicative stress through the awakening of dormant replication origins and profound alterations of the heterochromatin landscape. ZNF587/417 knockdown profoundly altered the transcriptomic landscape of U2932 (ABC) and OCI-Ly7 (GCB) cells, rewiring gene expression networks associated with good prognosis and upregulating interferon (IFN)/inflammatory-related genes through activation of the cGAS-STING DNA sensing pathway. These cells showed signs of altered immunogenicity with an enhanced MHC class I surface expression and a reshuffling of their immunopeptidome. Our study provides evidence that the ZNF587-ZNF417 paralog pair may promote lymphoma growth, the acquisition of genetic diversity, and its immune evasion by preventing excessive replicative stress. This suggests that these TFs participate in the epigenetic memory of lymphoma cells, thus highlighting the critical role of constitutive heterochromatin in maintaining the identity of poor-prognosis DLBCL.
2024-03-15 | PXD040500 | Pride