scholarly journals CCA1 and ATAF2 differentially suppress cytochrome P450-mediated brassinosteroid inactivation in Arabidopsis

2018 ◽  
Author(s):  
Hao Peng ◽  
Michael M. Neff
Keyword(s):  
Cytochrome P450 ◽  
Binding Sites ◽  
Expression Patterns ◽  
Regulatory Protein ◽  
Cytochrome P450s ◽  
Null Mutant ◽  
Yeast Two Hybrid ◽  
Protein Levels ◽  
The Core ◽  
Two Hybrid

AbstractBrassinosteroids (BRs) are a group of steroid hormones regulating plant growth and development. Since BRs do not undergo transport among plant tissues, their metabolism is tightly regulated by transcription factors (TFs) and feedback loops. BAS1 (CYP734A1, formerly CYP72B1) and SOB7 (CYP72C1) are two BR-inactivating cytochrome P450s identified in Arabidopsis thaliana. We previously found that a TF ATAF2 (ANAC081) suppresses BAS1 and SOB7 expression by binding to the Evening Element (EE) and CCA1-binding sites (CBS) on their promoters. Both EE and CBS are known binding targets of the core circadian clock regulatory protein CCA1. Here, we confirm that CCA1 binds the EE and CBS motifs on BAS1 and SOB7 promoters, respectively. Elevated accumulations of BAS1 and SOB7 transcripts in the CCA1 null mutant cca1-1 indicate that CCA1 is a repressor of their expression. When compared to either cca1-1 or the ATAF2 null mutant ataf2-2, the cca1-1 ataf2-2 double mutant shows higher SOB7 transcript accumulations and stronger BR-insensitive phenotype of hypocotyl elongation in white light. CCA1 interacts with ATAF2 at both DNA-protein and protein-protein levels. ATAF2, BAS1 and SOB7 are all circadian-regulated with distinct expression patterns. These results demonstrate that CCA1 and ATAF2 differentially suppress BAS1- and SOB7-mediated BR inactivation.HighlightThe core circadian regulator CCA1 is a direct repressor of brassinosteroid inactivating genes BAS1 and SOB7, and interact with another repressor, ATAF2. Their differential suppressing effects are regulated by light.Abbreviations3-aminotriazole (3-AT), brassinolide (BL), brassinosteroid (BR), CCA1-binding site (CBS), cytochrome P450 (P450), Evening Element (EE), transcription factor (TF), yeast one-hybrid (Y1H), yeast two-hybrid (Y2H)

scholarly journals CIRCADIAN CLOCK ASSOCIATED 1 and ATAF2 differentially suppress cytochrome P450-mediated brassinosteroid inactivation

2019 ◽  
Vol 71 (3) ◽  
pp. 970-985 ◽  
Author(s):  
Hao Peng ◽  
Michael M Neff
Keyword(s):  
Circadian Clock ◽  
Double Mutant ◽  
Expression Patterns ◽  
Regulatory Protein ◽  
Feedback Loops ◽  
Cytochrome P450s ◽  
Plant Tissues ◽  
Null Mutant ◽  
Plant Growth And Development ◽  
Protein Levels

Abstract Brassinosteroids (BRs) are a group of steroid hormones regulating plant growth and development. Since BRs do not undergo transport among plant tissues, their metabolism is tightly regulated by transcription factors (TFs) and feedback loops. BAS1 (CYP734A1, formerly CYP72B1) and SOB7 (CYP72C1) are two BR-inactivating cytochrome P450s identified in Arabidopsis thaliana. We previously found that a TF ATAF2 (ANAC081) suppresses BAS1 and SOB7 expression by binding to the Evening Element (EE) and CIRCADIAN CLOCK ASSOCIATED 1 (CCA1)-binding site (CBS) on their promoters. Both the EE and CBS are known binding targets of the circadian regulatory protein CCA1. Here, we confirm that CCA1 binds the EE and CBS motifs on BAS1 and SOB7 promoters, respectively. Elevated accumulations of BAS1 and SOB7 transcripts in the CCA1 null mutant cca1-1 indicate that CCA1 is a repressor of their expression. When compared with either cca1-1 or the ATAF2 null mutant ataf2-2, the cca1-1 ataf2-2 double mutant shows higher SOB7 transcript accumulations and a stronger BR-insensitive phenotype of hypocotyl elongation in white light. CCA1 interacts with ATAF2 at both DNA–protein and protein–protein levels. ATAF2, BAS1, and SOB7 are all circadian regulated with distinct expression patterns. These results demonstrate that CCA1 and ATAF2 differentially suppress BAS1- and SOB7-mediated BR inactivation.

scholarly journals Novel DnaJ Protein Facilitates Thermotolerance of Transgenic Tomatoes

2019 ◽  
Vol 20 (2) ◽  
pp. 367 ◽  
Author(s):  
Guodong Wang ◽  
Guohua Cai ◽  
Na Xu ◽  
Litao Zhang ◽  
Xiuling Sun ◽  
...  
Keyword(s):  
Heat Stress ◽  
D1 Protein ◽  
Heat Sensitivity ◽  
Yeast Two Hybrid ◽  
Protein Levels ◽  
Dnaj Protein ◽  
Yeast Two Hybrid System ◽  
Ros Accumulation ◽  
Transgenic Tomatoes ◽  
Two Hybrid

DnaJ proteins, which are molecular chaperones that are widely present in plants, can respond to various environmental stresses. At present, the function of DnaJ proteins was studied in many plant species, but only a few studies were conducted in tomato. Here, we examined the functions of a novel tomato (Solanum lycopersicum) DnaJ protein (SlDnaJ20) in heat tolerance using sense and antisense transgenic tomatoes. Transient conversion assays of Arabidopsis protoplasts showed that SlDnaJ20 was targeted to chloroplasts. Expression analysis showed that SlDnaJ20 expression was induced by chilling, NaCl, polyethylene glycol, and H2O2, especially via heat stress. Under heat stress, sense plants showed higher fresh weights, chlorophyll content, fluorescence (Fv/Fm), and D1 protein levels, and a lower accumulation of reactive oxygen species (ROS) than antisense plants. These results suggest that SlDnaJ20 overexpression can reduce the photoinhibition of photosystem II (PSII) by relieving ROS accumulation. Moreover, higher expression levels of HsfA1 and HsfB1 were observed under heat stress in sense plants, indicating that SlDnaJ20 overexpression contributes to HSF expression. The yeast two-hybrid system proved that SlDnaJ20 can interact with the chloroplast heat-shock protein 70. Our results indicate that SlDnaJ20 overexpression enhances the thermotolerance of transgenic tomatoes, whereas suppression of SlDnaJ20 increases the heat sensitivity of transgenic tomatoes.

scholarly journals Steroidogenic Acute Regulatory Protein-binding Protein Cloned by a Yeast Two-hybrid System

2003 ◽  
Vol 278 (43) ◽  
pp. 42487-42494 ◽  
Author(s):  
Teruo Sugawara ◽  
Hiroshi Shimizu ◽  
Nobuhiko Hoshi ◽  
Ayako Nakajima ◽  
Seiichiro Fujimoto
Keyword(s):  
Protein Binding ◽  
Hybrid System ◽  
Binding Protein ◽  
Regulatory Protein ◽  
Steroidogenic Acute Regulatory Protein ◽  
Yeast Two Hybrid ◽  
Yeast Two Hybrid System ◽  
Steroidogenic Acute Regulatory ◽  
Two Hybrid

scholarly journals Genome-Wide Analysis of the IQM Gene Family in Rice (Oryza sativa L.)

Plants ◽  
2021 ◽  
Vol 10 (9) ◽  
pp. 1949
Author(s):  
Tian Fan ◽  
Tianxiao Lv ◽  
Chuping Xie ◽  
Yuping Zhou ◽  
Changen Tian
Keyword(s):  
Abiotic Stress ◽  
Stress Response ◽  
Gene Family ◽  
Expression Profiles ◽  
Expression Patterns ◽  
Abiotic Stress Response ◽  
Biotic And Abiotic Stress ◽  
Yeast Two Hybrid ◽  
Iq Motif ◽  
Two Hybrid

Members of the IQM (IQ-Motif Containing) gene family are involved in plant growth and developmental processes, biotic and abiotic stress response. To systematically analyze the IQM gene family and their expression profiles under diverse biotic and abiotic stresses, we identified 8 IQM genes in the rice genome. In the current study, the whole genome identification and characterization of OsIQMs, including the gene and protein structure, genome localization, phylogenetic relationship, gene expression and yeast two-hybrid were performed. Eight IQM genes were classified into three subfamilies (I–III) according to the phylogenetic analysis. Gene structure and protein motif analyses showed that these IQM genes are relatively conserved within each subfamily of rice. The 8 OsIQM genes are distributed on seven out of the twelve chromosomes, with three IQM gene pairs involved in segmental duplication events. The evolutionary patterns analysis revealed that the IQM genes underwent a large-scale event within the last 20 to 9 million years. In addition, quantitative real-time PCR analysis of eight OsIQMs genes displayed different expression patterns at different developmental stages and in different tissues as well as showed that most IQM genes were responsive to PEG, NaCl, jasmonic acid (JA), abscisic acid (ABA) treatment, suggesting their crucial roles in biotic, and abiotic stress response. Additionally, a yeast two-hybrid assay showed that OsIQMs can interact with OsCaMs, and the IQ motif of OsIQMs is required for OsIQMs to combine with OsCaMs. Our results will be valuable to further characterize the important biological functions of rice IQM genes.

Gfi1 Protein Turnover Is Regulated by the Ubiquitin Ligase Triad1.

Blood ◽  
2006 ◽  
Vol 108 (11) ◽  
pp. 1173-1173
Author(s):  
Laurens T. van der Meer ◽  
Jurgen A.F. Marteijn ◽  
Theo M. de Witte ◽  
Joop H. Jansen ◽  
Bert A. van der Reijden
Keyword(s):  
Ubiquitin Ligase ◽  
Half Life ◽  
Proteasome Inhibitors ◽  
Ring Finger ◽  
Ubiquitin Ligases ◽  
Proteasomal Degradation ◽  
Mrna Levels ◽  
Yeast Two Hybrid ◽  
Protein Levels ◽  
Two Hybrid

Abstract The transcriptional repressor Growth factor independence-1 (Gfi1) plays an essential role during various stages of hematopoiesis. It is crucial for the self-renewal and long-term reconstituting potential of stem cells, essential for neutrophilic differentiation, and it plays an important role in T-cell and dendritic cell development. Gfi1 has also been implicated in malignant hematopoeisis because the Gfi1 gene is a common proviral integration site in murine leukemia models. We recently found that Gfi1 protein levels are mainly regulated by the ubiquitin-proteasome system. Although Gfi1 mRNA levels are low in primary human monocytes, the protein levels are high due to low proteasomal degradation. Conversely, in mature granulocytes Gfi1 mRNA levels are high but protein levels are low due to strong proteasome-mediated turnover. Because Gfi1 plays an important role in normal and malignant hematopoiesis it will be of great interest to identify the ubiquitin ligases that regulate its turnover. Previously, we showed that the RING finger ubiquitin ligase Triad1 regulates myeloid cell proliferation. Using yeast-two-hybrid assays we found that Triad1 binds the zinc finger region of Gfi1. This interaction was confirmed in co-immunoprecipitation experiments. To study whether the turnover of Gfi1 is regulated by Triad1 we performed ubiquitination assays. To our suprise we found that instead of promoting ubiquitination, Triad1 inhibited Gfi1 protein ubiquitination, also in the presence of proteasome inhibitors. RNAi mediated down regulation of Triad1 protein levels stimulated Gfi1 ubiquitination. Importantly, expression of a Triad1 point mutant (H158A) that fails to bind the ubiquitin conjugating enzyme UbcH7 also inhibited Gfi1 ubiquitination. To study whether the observed diminished ubiquitination by Triad1 affected the turnover of Gfi1 we analyzed Gfi1 protein half-life using the protein synthesis inhibitor cycloheximide. This showed that Triad1 co-expression prolonged the half-life of Gfi1 significantly. We conclude that Triad1 inhibits Gfi1 ubiquitination, resulting in decreased turnover of the protein. As this inhibition also occurs in the presence of proteasome inhibitors and is independent of the ubiquitin ligase activity of Triad1, these data support a model in which Triad1 competes for Gfi1 binding with other ubiquitin ligases that do mark Gfi1 for proteasomal degradation. Currently, we are testing candidate ubiquitin ligases (RING finger and HECT proteins) that were found to associate with Gfi1 in yeast-two-hybrid assays to gain more insight in how the activity of this important transcription factor is regulated.

scholarly journals Regulation of Glycosylphosphatidylinositol-Anchored Protein (GPI-AP) Expression by F-Box/LRR-Repeat (FBXL) Protein in Wheat (Triticum aestivum L.)

Plants ◽  
2021 ◽  
Vol 10 (8) ◽  
pp. 1606
Author(s):  
Min Jeong Hong ◽  
Jin-Baek Kim ◽  
Yong Weon Seo ◽  
Dae Yeon Kim
Keyword(s):  
Triticum Aestivum ◽  
Plasma Membrane ◽  
Fluorescent Protein ◽  
Expression Patterns ◽  
Triticum Aestivum L ◽  
26S Proteasome ◽  
Bimolecular Fluorescence Complementation ◽  
Yeast Two Hybrid ◽  
Scf Complex ◽  
Two Hybrid

F-box proteins are substrate recognition components of the Skp1-Cullin-F-box (SCF) complex, which performs many important biological functions including the degradation of numerous proteins via the ubiquitin–26S proteasome system. In this study, we isolated the gene encoding the F-box/LRR-repeat (FBXL) protein from wheat (Triticum aestivum L.) seedlings and validated that the TaFBXL protein is a component of the SCF complex. Yeast two-hybrid assays revealed that TaFBXL interacts with the wheat glycosylphosphatidylinositol-anchored protein (TaGPI-AP). The green fluorescent protein (GFP) fusion protein of TaFBXL was detected in the nucleus and plasma membrane, whereas that of TaGPI-AP was observed in the cytosol and probably also plasma membrane. yeast two-hybrid and bimolecular fluorescence complementation (BiFC) assays revealed that TaFBXL specifically interacts with TaGPI-AP in the nucleus and plasma membrane, and TaGPI-AP is targeted by TaFBXL for degradation via the 26S proteasome system. In addition, TaFBXL and TaGPI-AP showed antagonistic expression patterns upon treatment with indole-3-acetic acid (IAA), and the level of TaGPI-AP was higher in tobacco leaves treated with both MG132 (proteasome inhibitor) and IAA than in leaves treated with either MG132 or IAA. Taken together, our data suggest that TaFBXL regulates the TaGPI-AP protein level in response to exogenous auxin application.

scholarly journals Key role of the motor protein Kinesin 13B in the activity of homeodomain-leucine zipper I transcription factors

2020 ◽  
Vol 71 (20) ◽  
pp. 6282-6296
Author(s):  
Virginia Natali Miguel ◽  
Karina Fabiana Ribichich ◽  
Jorge Ignacio Giacomelli ◽  
Raquel Lia Chan
Keyword(s):  
Transcription Factors ◽  
Leucine Zipper ◽  
Molecular Mechanisms ◽  
Vascular Tissue ◽  
Expression Patterns ◽  
Motor Protein ◽  
Bimolecular Fluorescence Complementation ◽  
Yeast Two Hybrid ◽  
Cauline Leaf ◽  
Two Hybrid

Abstract The sunflower (Helianthus annuus) homeodomain-leucine zipper I transcription factor HaHB11 conferred differential phenotypic features when it was expressed in Arabidopsis, alfalfa, and maize plants. Such differences were increased biomass, seed yield, and tolerance to flooding. To elucidate the molecular mechanisms leading to such traits and identify HaHB11-interacting proteins, a yeast two-hybrid screening of an Arabidopsis cDNA library was carried out using HaHB11 as bait. The sole protein identified with high confidence as interacting with HaHB11 was Kinesin 13B. The interaction was confirmed by bimolecular fluorescence complementation and by yeast two-hybrid assay. Kinesin 13B also interacted with AtHB7, the Arabidopsis closest ortholog of HaHB11. Histochemical analyses revealed an overlap between the expression patterns of the three genes in hypocotyls, apical meristems, young leaves, vascular tissue, axillary buds, cauline leaves, and cauline leaf nodes at different developmental stages. AtKinesin 13B mutants did not exhibit a differential phenotype when compared with controls; however, both HaHB11 and AtHB7 overexpressor plants lost, partially or totally, their differential phenotypic characteristics when crossed with such mutants. Altogether, the results indicated that Kinesin 13B is essential for the homeodomain-leucine zipper transcription factors I to exert their functions, probably via regulation of the intracellular distribution of these transcription factors by the motor protein.

scholarly journals Drosophila homologs of the proto-oncogene product PEBP2/CBF beta regulate the DNA-binding properties of Runt.

1996 ◽  
Vol 16 (3) ◽  
pp. 932-942 ◽  
Author(s):  
G Golling ◽  
L Li ◽  
M Pepling ◽  
M Stebbins ◽  
J P Gergen
Keyword(s):  
Dna Binding ◽  
Expression Patterns ◽  
Yeast Two Hybrid ◽  
Binding Studies ◽  
Runt Domain ◽  
Big Brother ◽  
Functional Homology ◽  
Two Hybrid

The Drosophila runt gene is the founding member of the Runt domain family of transcriptional regulators. Mammalian Runt domain genes encode the alpha subunit of the heterometric DNA-binding factor PEBP2/CBF. The unrelated PEBP2/CBF beta protein interacts with the Runt domain to increase its affinity for DNA. The conserved ability of the Drosophila Runt protein to respond to the stimulating effect of mammalian PEBP2/CBF beta indicated that flies were likely to have a homologous beta protein. Using the yeast two-hybrid system to isolate cDNAs for Runt-interacting proteins, we identified two Drosophila genes, referred to as Brother and Big-brother, that have substantial sequence homology with PEBP2/CBF beta. Yeast two-hybrid experiments as well as in vitro DNA-binding studies confirmed the functional homology of the Brother, Big-brother, and PEBP2/CBF beta proteins and demonstrated that the conserved regions of the Runt and Brother proteins are required for their heterodimeric interaction. The DNA-bending properties of Runt domain proteins in the presence and absence of their partners were also examined. Our results show that Runt domain proteins bend DNA and that this bending is influenced by Brother protein family members, supporting the idea that heterodimerization is associated with a conformational change in the Runt domain. Analysis of expression patterns in Drosophila embryos revealed that Brother and Big-brother are likely to interact with runt in vivo and further suggested that the activity of these proteins is not restricted to their interaction with Runt.

scholarly journals The Peptidyl Prolyl cis/trans Isomerase FKBP38 Determines Hypoxia-Inducible Transcription Factor Prolyl-4-Hydroxylase PHD2 Protein Stability

2007 ◽  
Vol 27 (10) ◽  
pp. 3758-3768 ◽  
Author(s):  
Sandra Barth ◽  
Jutta Nesper ◽  
Philippe A. Hasgall ◽  
Renato Wirthner ◽  
Katarzyna J. Nytko ◽  
...  
Keyword(s):  
Protein Stability ◽  
Transcriptional Activity ◽  
Mrna Levels ◽  
Yeast Two Hybrid ◽  
Isomerase Activity ◽  
Fk506 Binding Protein ◽  
Protein Levels ◽  
Hypoxic Conditions ◽  
Α Subunits ◽  
Two Hybrid

ABSTRACT The heterodimeric hypoxia-inducible transcription factors (HIFs) are central regulators of the response to low oxygenation. HIF-α subunits are constitutively expressed but rapidly degraded under normoxic conditions. Oxygen-dependent hydroxylation of two conserved prolyl residues by prolyl-4-hydroxylase domain-containing enzymes (PHDs) targets HIF-α for proteasomal destruction. We identified the peptidyl prolyl cis/trans isomerase FK506-binding protein 38 (FKBP38) as a novel interactor of PHD2. Yeast two-hybrid, glutathione S-transferase pull-down, coimmunoprecipitation, colocalization, and mammalian two-hybrid studies confirmed specific FKBP38 interaction with PHD2, but not with PHD1 or PHD3. PHD2 and FKBP38 associated with their N-terminal regions, which contain no known interaction motifs. Neither FKBP38 mRNA nor protein levels were regulated under hypoxic conditions or after PHD inhibition, suggesting that FKBP38 is not a HIF/PHD target. Stable RNA interference-mediated depletion of FKBP38 resulted in increased PHD hydroxylation activity and decreased HIF protein levels and transcriptional activity. Reconstitution of FKBP38 expression abolished these effects, which were independent of the peptidyl prolyl cis/trans isomerase activity. Downregulation of FKBP38 did not affect PHD2 mRNA levels but prolonged PHD2 protein stability, suggesting that FKBP38 is involved in PHD2 protein regulation.

Sign in / Sign up

Export Citation Format

Share Document