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Zhao X, Wang Q, Yan C, Sun Q, Wang J, Li C, Yuan C, Mou Y, Shan S. The bHLH transcription factor AhbHLH121 improves salt tolerance in peanut. Int J Biol Macromol 2024; 256:128492. [PMID: 38035960 DOI: 10.1016/j.ijbiomac.2023.128492] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2023] [Revised: 11/26/2023] [Accepted: 11/27/2023] [Indexed: 12/02/2023]
Abstract
Plants have developed a number of protective mechanisms to respond to salt and other stresses. Previous studies have shown that the basic helix-loop-helix (bHLH) transcription factor AhbHLH121 plays a crucial role in the response to abiotic stresses in peanut, but the mechanisms and functions related to AhbHLH121 remain unclear. In the current research, AhbHLH121 was induced by salt treatment. Overexpression of AhbHLH121 improved salt resistance, whereas silencing AhbHLH121 resulted in the inverse correlation. Our results also demonstrated that overexpression of AhbHLH121 results in greater activity of antioxidant enzymes under stress condition by promoting the expression of the genes for peroxidase, catalase and superoxide dismutase (AhPOD, AhCAT and AhSOD), indicating enhanced scavenging of reactive oxygen species. Further analysis including Yeast one-hybrid (Y1H) assays and electrophoretic mobility shift assays (EMSAs), suggested that AhbHLH121 can bind directly to the G/E-box regions of the AhPOD, AhCAT and AhSOD promoters, thereby promoting their expression and leading to improved antioxidant enzyme activity. Our research improves the understanding of the mechanisms that allow this peanut bHLH transcription factor to improve abiotic tolerance, and provides valuable gene resources for breeding programs to promote salt stress resistance.
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Affiliation(s)
- Xiaobo Zhao
- Shandong Peanut Research Institute, Qingdao 266100, China.
| | - Qi Wang
- Shandong Peanut Research Institute, Qingdao 266100, China
| | - Caixia Yan
- Shandong Peanut Research Institute, Qingdao 266100, China
| | - Quanxi Sun
- Shandong Peanut Research Institute, Qingdao 266100, China
| | - Juan Wang
- Shandong Peanut Research Institute, Qingdao 266100, China
| | - Chunjuan Li
- Shandong Peanut Research Institute, Qingdao 266100, China
| | - Cuiling Yuan
- Shandong Peanut Research Institute, Qingdao 266100, China
| | - Yifei Mou
- Shandong Peanut Research Institute, Qingdao 266100, China
| | - Shihua Shan
- Shandong Peanut Research Institute, Qingdao 266100, China.
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Radani Y, Li R, Korboe HM, Ma H, Yang L. Transcriptional and Post-Translational Regulation of Plant bHLH Transcription Factors during the Response to Environmental Stresses. Plants (Basel) 2023; 12:plants12112113. [PMID: 37299095 DOI: 10.3390/plants12112113] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/19/2023] [Revised: 05/16/2023] [Accepted: 05/19/2023] [Indexed: 06/12/2023]
Abstract
Over the past decades, extensive research has been conducted to identify and characterize various plant transcription factors involved in abiotic stress responses. Therefore, numerous efforts have been made to improve plant stress tolerance by engineering these transcription factor genes. The plant basic Helix-Loop-Helix (bHLH) transcription factor family represents one of the most prominent gene families and contains a bHLH motif that is highly conserved in eukaryotic organisms. By binding to specific positions in promoters, they activate or repress the transcription of specific response genes and thus affect multiple variables in plant physiology such as the response to abiotic stresses, which include drought, climatic variations, mineral deficiencies, excessive salinity, and water stress. The regulation of bHLH transcription factors is crucial to better control their activity. On the one hand, they are regulated at the transcriptional level by other upstream components; on the other hand, they undergo various modifications such as ubiquitination, phosphorylation, and glycosylation at the post-translational level. Modified bHLH transcription factors can form a complex regulatory network to regulate the expression of stress response genes and thus determine the activation of physiological and metabolic reactions. This review article focuses on the structural characteristics, classification, function, and regulatory mechanism of bHLH transcription factor expression at the transcriptional and post-translational levels during their responses to various abiotic stress conditions.
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Affiliation(s)
- Yasmina Radani
- State Key Laboratory of Tree Genetics and Breeding, Co-Innovation Center for Sustainable Forestry in Southern China, College of Biology and the Environment, Nanjing Forestry University, Nanjing 210037, China
| | - Rongxue Li
- State Key Laboratory of Tree Genetics and Breeding, Co-Innovation Center for Sustainable Forestry in Southern China, College of Biology and the Environment, Nanjing Forestry University, Nanjing 210037, China
| | - Harriet Mateko Korboe
- State Key Laboratory of Tree Genetics and Breeding, Co-Innovation Center for Sustainable Forestry in Southern China, College of Biology and the Environment, Nanjing Forestry University, Nanjing 210037, China
| | - Hongyu Ma
- College of Plant Protection, Nanjing Agricultural University, Nanjing 210095, China
| | - Liming Yang
- State Key Laboratory of Tree Genetics and Breeding, Co-Innovation Center for Sustainable Forestry in Southern China, College of Biology and the Environment, Nanjing Forestry University, Nanjing 210037, China
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Wang N, Shu X, Zhang F, Wang Z. Transcriptome-wide characterization of bHLH transcription factor genes in Lycoris radiata and functional analysis of their response to MeJA. Front Plant Sci 2023; 13:975530. [PMID: 36704164 PMCID: PMC9872026 DOI: 10.3389/fpls.2022.975530] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/22/2022] [Accepted: 12/12/2022] [Indexed: 06/18/2023]
Abstract
As one of the biggest plant specific transcription factor (TF) families, basic helix-loop-helix (bHLH) protein, plays significant roles in plant growth, development, and abiotic stress responses. However, there has been minimal research about the effects of methyl jasmonate (MeJA) treatment on the bHLH gene family in Lycoris radiata (L'Her.) Herb. In this study, based on transcriptome sequencing data, 50 putative L. radiata bHLH (LrbHLH) genes with complete open reading frames (ORFs), which were divided into 20 bHLH subfamilies, were identified. The protein motif analyses showed that a total of 10 conserved motifs were found in LrbHLH proteins and motif 1 and motif 2 were the most highly conserved motifs. Gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis of LrbHLH genes revealed their involvement in regulation of plant growth, jasmonic acid (JA) mediated signaling pathway, photoperiodism, and flowering. Furthermore, subcellular localization revealed that most LrbHLHs were located in the nucleus. Expression pattern analysis of LrbHLH genes in different tissues and at flower developmental stages suggested that their expression differed across lineages and might be important for plant growth and organ development in Lycoris. In addition, all LrbHLH genes exhibited specific spatial and temporal expression patterns under MeJA treatment. Moreover, protein-protein interaction (PPI) network analysis and yeast two-hybrid assay showed that numerous LrbHLHs could interact with jasmonate ZIM (zinc-finger inflorescence meristem) domain (JAZ) proteins. This research provides a theoretical basis for further investigation of LrbHLHs to find their functions and insights for their regulatory mechanisms involved in JA signaling pathway.
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Gao Q, Song W, Li X, Xiang C, Chen G, Xiang G, Liu X, Zhang G, Li X, Yang S, Zhai C, Zhao Y. Genome-wide identification of bHLH transcription factors: Discovery of a candidate regulator related to flavonoid biosynthesis in Erigeron breviscapus. Front Plant Sci 2022; 13:977649. [PMID: 36186051 PMCID: PMC9515989 DOI: 10.3389/fpls.2022.977649] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/24/2022] [Accepted: 08/15/2022] [Indexed: 06/16/2023]
Abstract
Erigeron breviscapus is a Compositae plant, and its rich flavonoids have shown strong preventative and curative effects in the treatment of cardio- and cerebrovascular diseases. bHLH genes play a crucial role in plant growth and development. There are 116 EbbHLH genes in E. breviscapus, and each gene has been named based on its chromosome location. Our phylogenetic analysis divided these genes into 18 subfamilies. To further investigate its function, EbbHLH80 was isolated from E. breviscapus leaves. Next, transcriptomic and metabolomic analyses of tobacco leaves were performed. Among 421 differentially accumulated compounds, 98 flavonoids were identified. In addition, differentially expressed genes were identified using RNA-seq, and further analysis suggested that EbbHLH80-OE could not only regulate the expression of some structural genes in the flavonoid biosynthesis pathway to achieve flavonoid accumulation but also be involved in the regulation of a series of downstream pathways, such as stress response, ABA and ethylene signal transduction, to affect plant growth and development. The results of our analysis provide new insights into the function of EbbHLH80 and lay the foundation for future functional studies on E. breviscapus.
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Affiliation(s)
- Qingqing Gao
- Key Laboratory of Medicinal Plant Biology of Yunnan Province, National and Local Joint Engineering Research Center on Germplasms Innovation and Utilization of Chinese Medicinal Materials in Southwest China, Yunnan Agricultural University, Kunming, China
- College of Agronomy and Biotechnology, Yunnan Agricultural University, Kunming, China
| | - Wanling Song
- Key Laboratory of Medicinal Plant Biology of Yunnan Province, National and Local Joint Engineering Research Center on Germplasms Innovation and Utilization of Chinese Medicinal Materials in Southwest China, Yunnan Agricultural University, Kunming, China
- College of Agronomy and Biotechnology, Yunnan Agricultural University, Kunming, China
| | - Xia Li
- Key Laboratory of Medicinal Plant Biology of Yunnan Province, National and Local Joint Engineering Research Center on Germplasms Innovation and Utilization of Chinese Medicinal Materials in Southwest China, Yunnan Agricultural University, Kunming, China
- College of Agronomy and Biotechnology, Yunnan Agricultural University, Kunming, China
| | - Chunfan Xiang
- Key Laboratory of Medicinal Plant Biology of Yunnan Province, National and Local Joint Engineering Research Center on Germplasms Innovation and Utilization of Chinese Medicinal Materials in Southwest China, Yunnan Agricultural University, Kunming, China
- College of Agronomy and Biotechnology, Yunnan Agricultural University, Kunming, China
| | - Geng Chen
- Key Laboratory of Medicinal Plant Biology of Yunnan Province, National and Local Joint Engineering Research Center on Germplasms Innovation and Utilization of Chinese Medicinal Materials in Southwest China, Yunnan Agricultural University, Kunming, China
- College of Agronomy and Biotechnology, Yunnan Agricultural University, Kunming, China
| | - Guisheng Xiang
- Key Laboratory of Medicinal Plant Biology of Yunnan Province, National and Local Joint Engineering Research Center on Germplasms Innovation and Utilization of Chinese Medicinal Materials in Southwest China, Yunnan Agricultural University, Kunming, China
| | - Xiangyu Liu
- Key Laboratory of Medicinal Plant Biology of Yunnan Province, National and Local Joint Engineering Research Center on Germplasms Innovation and Utilization of Chinese Medicinal Materials in Southwest China, Yunnan Agricultural University, Kunming, China
| | - Guanghui Zhang
- Key Laboratory of Medicinal Plant Biology of Yunnan Province, National and Local Joint Engineering Research Center on Germplasms Innovation and Utilization of Chinese Medicinal Materials in Southwest China, Yunnan Agricultural University, Kunming, China
| | - Xiaoning Li
- Key Laboratory of Medicinal Plant Biology of Yunnan Province, National and Local Joint Engineering Research Center on Germplasms Innovation and Utilization of Chinese Medicinal Materials in Southwest China, Yunnan Agricultural University, Kunming, China
| | - Shengchao Yang
- Key Laboratory of Medicinal Plant Biology of Yunnan Province, National and Local Joint Engineering Research Center on Germplasms Innovation and Utilization of Chinese Medicinal Materials in Southwest China, Yunnan Agricultural University, Kunming, China
| | - Chenxi Zhai
- Sibley School of Mechanical and Aerospace Engineering, Cornell University, Ithaca, NY, United States
| | - Yan Zhao
- Key Laboratory of Medicinal Plant Biology of Yunnan Province, National and Local Joint Engineering Research Center on Germplasms Innovation and Utilization of Chinese Medicinal Materials in Southwest China, Yunnan Agricultural University, Kunming, China
- College of Agronomy and Biotechnology, Yunnan Agricultural University, Kunming, China
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Dong Y, Zhang W, Li J, Wang D, Bai H, Li H, Shi L. The transcription factor LaMYC4 from lavender regulates volatile Terpenoid biosynthesis. BMC Plant Biol 2022; 22:289. [PMID: 35698036 PMCID: PMC9190104 DOI: 10.1186/s12870-022-03660-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/28/2022] [Accepted: 05/25/2022] [Indexed: 06/15/2023]
Abstract
BACKGROUND The basic helix-loop-helix (bHLH) transcription factors (TFs), as one of the largest families of TFs, are essential regulators of plant terpenoid biosynthesis and response to stresses. Lavender has more than 75 volatile terpenoids, yet few TFs have been identified to be involved in the terpenoid biosynthesis. RESULTS Based on RNA-Seq, reverse transcription-quantitative polymerase chain reaction, and transgenic technology, this study characterized the stress-responsive transcription factor LaMYC4 regulates terpenoid biosynthesis. Methyl jasmonate (MeJA) treatment increased volatile terpenoid emission, and the differentially expressed gene LaMYC4 was isolated. LaMYC4 expression level was higher in leaf than in other tissues. The expression of LaMYC4 decreased during flower development. The promoter of LaMYC4 contained hormone and stress-responsive regulatory elements and was responsive to various treatments, including UV, MeJA treatment, drought, low temperature, Pseudomonas syringae infection, and NaCl treatment. LaMYC4 overexpression increased the levels of sesquiterpenoids, including caryophyllenes, in Arabidopsis and tobacco plants. Furthermore, the expression of crucial node genes involved in terpenoid biosynthesis and glandular trichome number and size increased in transgenic tobacco. CONCLUSIONS We have shown that the stress-responsive MYC TF LaMYC4 from 'Jingxun 2' lavender regulates volatile terpenoid synthesis. This study is the first to describe the cloning of LaMYC4, and the results help understand the role of LaMYC4 in terpenoid biosynthesis.
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Affiliation(s)
- Yanmei Dong
- Key Laboratory of Plant Resources and Beijing Botanical Garden, Institute of Botany, Chinese Academy of Sciences, Xiangshan, Beijing, 100093 China
- University of Chinese Academy of Sciences, Beijing, 100015 China
| | - Wenying Zhang
- Key Laboratory of Plant Resources and Beijing Botanical Garden, Institute of Botany, Chinese Academy of Sciences, Xiangshan, Beijing, 100093 China
- University of Chinese Academy of Sciences, Beijing, 100015 China
| | - Jingrui Li
- Key Laboratory of Plant Resources and Beijing Botanical Garden, Institute of Botany, Chinese Academy of Sciences, Xiangshan, Beijing, 100093 China
| | - Di Wang
- Key Laboratory of Plant Resources and Beijing Botanical Garden, Institute of Botany, Chinese Academy of Sciences, Xiangshan, Beijing, 100093 China
| | - Hongtong Bai
- Key Laboratory of Plant Resources and Beijing Botanical Garden, Institute of Botany, Chinese Academy of Sciences, Xiangshan, Beijing, 100093 China
| | - Hui Li
- Key Laboratory of Plant Resources and Beijing Botanical Garden, Institute of Botany, Chinese Academy of Sciences, Xiangshan, Beijing, 100093 China
| | - Lei Shi
- Key Laboratory of Plant Resources and Beijing Botanical Garden, Institute of Botany, Chinese Academy of Sciences, Xiangshan, Beijing, 100093 China
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Wang W, Ye J, Xu H, Liu X, Fu Y, Zhang H, Rouached H, Whelan J, Shen Z, Zheng L. OsbHLH061 links TOPLESS/TOPLESS-RELATED repressor proteins with POSITIVE REGULATOR OF IRON HOMEOSTASIS 1 to maintain iron homeostasis in rice. New Phytol 2022; 234:1753-1769. [PMID: 35288933 DOI: 10.1111/nph.18096] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/21/2021] [Accepted: 02/28/2022] [Indexed: 05/16/2023]
Abstract
As excess iron (Fe) is toxic, uptake of this essential micronutrient must be tightly controlled. Previous studies have shown that Oryza sativa (rice) POSITIVE REGULATOR OF IRON HOMEOSTASIS1 (OsPRI1) acts upstream of the iron-related transcription factor 2 (OsIRO2) and OsIRO3 to positively regulate root-to-shoot Fe translocation. However, as expression of OsPRI1 is constitutive it is unclear how the Fe-deficiency response is turned off to prevent toxicity when Fe is sufficient. The bHLH transcription factor OsbHLH061 interacts with OsPRI1, and this study used molecular, genetics, biochemical and physiological approaches to functionally characterise OsbHLH061 and how it affects Fe homeostasis. OsbHLH061 knockout or overexpression lines increase or decrease Fe accumulation in shoots respectively. Mechanistically, OsbHLH061 expression is upregulated by high Fe, and physically interacts with OsPRI1, the OsbHLH061-OsPRI1 complex recruits TOPLESS/TOPLESS-RELATED (OsTPL/TPR) co-repressors to repress OsIRO2 and OsIRO3 expression. The OsbHLH061 ethylene-responsive element-binding factor-associated amphiphilic repression (EAR) motif is required for this transcriptional repression activity. These results define a functional OsTPL/TPR-OsbHLH061-OsPRI1-OsIRO2/3 module that negatively controls long-distance transport of Fe in plants for adaptation to changing Fe environments and maintain Fe homeostasis in rice.
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Affiliation(s)
- Wujian Wang
- College of Life Sciences, Nanjing Agricultural University, Nanjing, Jiangsu, 210095, China
| | - Jun Ye
- College of Life Sciences, Nanjing Agricultural University, Nanjing, Jiangsu, 210095, China
| | - Heng Xu
- College of Life Sciences, Nanjing Agricultural University, Nanjing, Jiangsu, 210095, China
| | - Xi Liu
- College of Life Sciences, Nanjing Agricultural University, Nanjing, Jiangsu, 210095, China
| | - Yue Fu
- College of Life Sciences, Nanjing Agricultural University, Nanjing, Jiangsu, 210095, China
| | - Hui Zhang
- College of Life Sciences, Nanjing Agricultural University, Nanjing, Jiangsu, 210095, China
| | - Hatem Rouached
- Department of Plant, Soil, and Microbial Sciences, Michigan State University, East Lansing, MI, 48824, USA
| | - James Whelan
- Department of Animal, Plant and Soil Sciences, ARC Centre of Excellence in Plant Energy Biology, School of Life Sciences, La Trobe University, Bundoora, Vic., 3086, Australia
| | - Zhenguo Shen
- College of Life Sciences, Nanjing Agricultural University, Nanjing, Jiangsu, 210095, China
| | - Luqing Zheng
- College of Life Sciences, Nanjing Agricultural University, Nanjing, Jiangsu, 210095, China
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7
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Littleford HE, Kiontke K, Fitch DHA, Greenwald I. hlh-12, a gene that is necessary and sufficient to promote migration of gonadal regulatory cells in Caenorhabditis elegans, evolved within the Caenorhabditis clade. Genetics 2021; 219:iyab127. [PMID: 34740245 PMCID: PMC8570790 DOI: 10.1093/genetics/iyab127] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2021] [Accepted: 07/30/2021] [Indexed: 11/12/2022] Open
Abstract
Specialized cells of the somatic gonad primordium of nematodes play important roles in the final form and function of the mature gonad. Caenorhabditis elegans hermaphrodites are somatic females that have a two-armed, U-shaped gonad that connects to the vulva at the midbody. The outgrowth of each gonad arm from the somatic gonad primordium is led by two female distal tip cells (fDTCs), while the anchor cell (AC) remains stationary and central to coordinate uterine and vulval development. The bHLH protein HLH-2 and its dimerization partners LIN-32 and HLH-12 had previously been shown to be required for fDTC specification. Here, we show that ectopic expression of both HLH-12 and LIN-32 in cells with AC potential transiently transforms them into fDTC-like cells. Furthermore, hlh-12 was known to be required for the fDTCs to sustain gonad arm outgrowth. Here, we show that ectopic expression of HLH-12 in the normally stationary AC causes displacement from its normal position and that displacement likely results from activation of the leader program of fDTCs because it requires genes necessary for gonad arm outgrowth. Thus, HLH-12 is both necessary and sufficient to promote gonadal regulatory cell migration. As differences in female gonadal morphology of different nematode species reflect differences in the fate or migratory properties of the fDTCs or of the AC, we hypothesized that evolutionary changes in the expression of hlh-12 may underlie the evolution of such morphological diversity. However, we were unable to identify an hlh-12 ortholog outside of Caenorhabditis. Instead, by performing a comprehensive phylogenetic analysis of all Class II bHLH proteins in multiple nematode species, we found that hlh-12 evolved within the Caenorhabditis clade, possibly by duplicative transposition of hlh-10. Our analysis suggests that control of gene regulatory hierarchies for gonadogenesis can be remarkably plastic during evolution without adverse phenotypic consequence.
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Affiliation(s)
- Hana E Littleford
- Department of Biological Sciences, Columbia University, New York, NY 10027, USA
| | - Karin Kiontke
- Department of Biology, Center for Developmental Genetics, New York University, New York, NY 10003, USA
| | - David H A Fitch
- Department of Biology, Center for Developmental Genetics, New York University, New York, NY 10003, USA
| | - Iva Greenwald
- Department of Biological Sciences, Columbia University, New York, NY 10027, USA
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Todd L, Hooper MJ, Haugan AK, Finkbeiner C, Jorstad N, Radulovich N, Wong CK, Donaldson PC, Jenkins W, Chen Q, Rieke F, Reh TA. Efficient stimulation of retinal regeneration from Müller glia in adult mice using combinations of proneural bHLH transcription factors. Cell Rep 2021; 37:109857. [PMID: 34686336 PMCID: PMC8691131 DOI: 10.1016/j.celrep.2021.109857] [Citation(s) in RCA: 62] [Impact Index Per Article: 20.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2021] [Revised: 09/02/2021] [Accepted: 09/28/2021] [Indexed: 12/27/2022] Open
Abstract
Regenerative neuroscience aims to stimulate endogenous repair in the nervous system to replace neurons lost from degenerative diseases. Recently, we reported that overexpressing the transcription factor Ascl1 in Müller glia (MG) is sufficient to stimulate MG to regenerate functional neurons in the adult mouse retina. However, this process is inefficient, and only a third of the Ascl1-expressing MG generate new neurons. Here, we test whether proneural transcription factors of the Atoh1/7 class can further promote the regenerative capacity of MG. We find that the combination of Ascl1:Atoh1 is remarkably efficient at stimulating neurogenesis, even in the absence of retinal injury. Using electrophysiology and single-cell RNA sequencing (scRNA-seq), we demonstrate that Ascl1:Atoh1 generates a diversity of retinal neuron types, with the majority expressing characteristics of retinal ganglion cells. Our results provide a proof of principle that combinations of developmental transcription factors can substantially improve glial reprogramming to neurons and expand the repertoire of regenerated cell fates.
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Affiliation(s)
- Levi Todd
- Department of Biological Structure, University of Washington, Seattle, WA 98195, USA
| | - Marcus J Hooper
- Department of Biological Structure, University of Washington, Seattle, WA 98195, USA
| | - Alexandra K Haugan
- Department of Biological Structure, University of Washington, Seattle, WA 98195, USA
| | - Connor Finkbeiner
- Department of Biological Structure, University of Washington, Seattle, WA 98195, USA
| | - Nikolas Jorstad
- Department of Biological Structure, University of Washington, Seattle, WA 98195, USA
| | - Nicholas Radulovich
- Department of Biological Structure, University of Washington, Seattle, WA 98195, USA
| | - Claire K Wong
- Department of Biological Structure, University of Washington, Seattle, WA 98195, USA
| | - Phoebe C Donaldson
- Department of Biological Structure, University of Washington, Seattle, WA 98195, USA
| | - Wesley Jenkins
- Department of Biological Structure, University of Washington, Seattle, WA 98195, USA
| | - Qiang Chen
- Department of Physiology and Biophysics, University of Washington, Seattle, WA 91895, USA
| | - Fred Rieke
- Department of Physiology and Biophysics, University of Washington, Seattle, WA 91895, USA
| | - Thomas A Reh
- Department of Biological Structure, University of Washington, Seattle, WA 98195, USA.
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9
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Yoshikawa G, Miyazaki K, Ogata H, Miyazaki M. The Evolution of Rag Gene Enhancers and Transcription Factor E and Id Proteins in the Adaptive Immune System. Int J Mol Sci 2021; 22:ijms22115888. [PMID: 34072618 PMCID: PMC8199221 DOI: 10.3390/ijms22115888] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2021] [Revised: 05/23/2021] [Accepted: 05/24/2021] [Indexed: 11/17/2022] Open
Abstract
Adaptive immunity relies on the V(D)J DNA recombination of immunoglobulin (Ig) and T cell receptor (TCR) genes, which enables the recognition of highly diverse antigens and the elicitation of antigen-specific immune responses. This process is mediated by recombination-activating gene (Rag) 1 and Rag2 (Rag1/2), whose expression is strictly controlled in a cell type-specific manner; the expression of Rag1/2 genes represents a hallmark of lymphoid lineage commitment. Although Rag genes are known to be evolutionally conserved among jawed vertebrates, how Rag genes are regulated by lineage-specific transcription factors (TFs) and how their regulatory system evolved among vertebrates have not been fully elucidated. Here, we reviewed the current body of knowledge concerning the cis-regulatory elements (CREs) of Rag genes and the evolution of the basic helix-loop-helix TF E protein regulating Rag gene CREs, as well as the evolution of the antagonist of this protein, the Id protein. This may help to understand how the adaptive immune system develops along with the evolution of responsible TFs and enhancers.
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Affiliation(s)
- Genki Yoshikawa
- Bioinformatics Center, Institute for Chemical Research, Kyoto University, Uji 611-0011, Japan;
| | - Kazuko Miyazaki
- Laboratory of Immunology, Institute for Frontier Life and Medical Sciences, Kyoto University, Kyoto 606-8507, Japan;
| | - Hiroyuki Ogata
- Bioinformatics Center, Institute for Chemical Research, Kyoto University, Uji 611-0011, Japan;
- Correspondence: (H.O.); (M.M.)
| | - Masaki Miyazaki
- Laboratory of Immunology, Institute for Frontier Life and Medical Sciences, Kyoto University, Kyoto 606-8507, Japan;
- Correspondence: (H.O.); (M.M.)
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10
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Vincentz JW, Firulli BA, Toolan KP, Osterwalder M, Pennacchio LA, Firulli AB. HAND transcription factors cooperatively specify the aorta and pulmonary trunk. Dev Biol 2021; 476:1-10. [PMID: 33757801 DOI: 10.1016/j.ydbio.2021.03.011] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2020] [Revised: 03/11/2021] [Accepted: 03/15/2021] [Indexed: 01/11/2023]
Abstract
Congenital heart defects (CHDs) affecting the cardiac outflow tract (OFT) constitute a significant cause of morbidity and mortality. The OFT develops from migratory cell populations which include the cardiac neural crest cells (cNCCs) and secondary heart field (SHF) derived myocardium and endocardium. The related transcription factors HAND1 and HAND2 have been implicated in human CHDs involving the OFT. Although Hand1 is expressed within the OFT, Hand1 NCC-specific conditional knockout mice (H1CKOs) are viable. Here we show that these H1CKOs present a low penetrance of OFT phenotypes, whereas SHF-specific Hand1 ablation does not reveal any cardiac phenotypes. Further, HAND1 and HAND2 appear functionally redundant within the cNCCs, as a reduction/ablation of Hand2 on an NCC-specific H1CKO background causes pronounced OFT defects. Double conditional Hand1 and Hand2 NCC knockouts exhibit persistent truncus arteriosus (PTA) with 100% penetrance. NCC lineage-tracing and Sema3c in situ mRNA expression reveal that Sema3c-expressing cells are mis-localized, resulting in a malformed septal bridge within the OFTs of H1CKO;H2CKO embryos. Interestingly, Hand1 and Hand2 also genetically interact within the SHF, as SHF H1CKOs on a heterozygous Hand2 background exhibit Ventricular Septal Defects (VSDs) with incomplete penetrance. Previously, we identified a BMP, HAND2, and GATA-dependent Hand1 OFT enhancer sufficient to drive reporter gene expression within the nascent OFT and aorta. Using these transcription inputs as a probe, we identify a novel Hand2 OFT enhancer, suggesting that a conserved BMP-GATA dependent mechanism transcriptionally regulates both HAND factors. These findings support the hypothesis that HAND factors interpret BMP signaling within the cNCCs to cooperatively coordinate OFT morphogenesis.
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Affiliation(s)
- Joshua W Vincentz
- Herman B Wells Center for Pediatric Research Department of Pediatrics, Anatomy, Biochemistry, and Medical and Molecular Genetics, Indiana University School of Medicine, 1044 W. Walnut St., Indianapolis, IN, 46202-5225, USA.
| | - Beth A Firulli
- Herman B Wells Center for Pediatric Research Department of Pediatrics, Anatomy, Biochemistry, and Medical and Molecular Genetics, Indiana University School of Medicine, 1044 W. Walnut St., Indianapolis, IN, 46202-5225, USA
| | - Kevin P Toolan
- Herman B Wells Center for Pediatric Research Department of Pediatrics, Anatomy, Biochemistry, and Medical and Molecular Genetics, Indiana University School of Medicine, 1044 W. Walnut St., Indianapolis, IN, 46202-5225, USA
| | - Marco Osterwalder
- Environmental Genomics and Systems Biology Division, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA; Department for BioMedical Research (DBMR), University of Bern, Murtenstrasse 35, 3008, Bern, Switzerland
| | - Len A Pennacchio
- Environmental Genomics and Systems Biology Division, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA; U.S. Department of Energy Joint Genome Institute, Berkeley, CA, 94720, USA; Comparative Biochemistry Program, University of California, Berkeley, CA, 94720, USA
| | - Anthony B Firulli
- Herman B Wells Center for Pediatric Research Department of Pediatrics, Anatomy, Biochemistry, and Medical and Molecular Genetics, Indiana University School of Medicine, 1044 W. Walnut St., Indianapolis, IN, 46202-5225, USA.
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11
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Abstract
Iron (Fe) is one of the essential micronutrients required by both plants and animals. In humans, Fe deficiency causes anemia, the most prevalent nutritional disorder. Most people rely on plant-based foods as their major Fe source, but plants are a poor source of dietary Fe. Therefore, there is a critical need to better understand the mechanisms involved in the uptake and trafficking of Fe and how plants adapt to Fe deficiency. Fe participates in key cellular functions such as photosynthesis and respiration. Perturbations of Fe uptake, transport, or storage affect plant growth as well as crop yield and plant product quality. Excess Fe has toxic effects due to its high redox activity. Plants, therefore, tightly regulate Fe uptake, distribution, and allocation. Here, we review the regulatory mechanisms involved at the transcriptional and post-translational levels that are critical to prevent Fe uptake except when plants experience Fe deficiency. We discuss the key regulatory network of basic helix-loop-helix (bHLH) transcription factors, including FIT, subgroup Ib, subgroup IVc, and URI (bHLH121), crucial for regulating Fe uptake in Arabidopsis thaliana. Furthermore, we describe the regulators of these transcription factors that either activate or inhibit their function, ensuring optimal Fe uptake that is essential for plant growth.
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Affiliation(s)
- Nabila Riaz
- Department of Biological Sciences, Dartmouth College, Hanover, NH, USA
| | - Mary Lou Guerinot
- Department of Biological Sciences, Dartmouth College, Hanover, NH, USA
- Correspondence:
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12
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Zhao W, Liu Y, Li L, Meng H, Yang Y, Dong Z, Wang L, Wu G. Genome-Wide Identification and Characterization of bHLH Transcription Factors Related to Anthocyanin Biosynthesis in Red Walnut ( Juglans regia L.). Front Genet 2021; 12:632509. [PMID: 33719341 PMCID: PMC7943622 DOI: 10.3389/fgene.2021.632509] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2020] [Accepted: 01/21/2021] [Indexed: 12/31/2022] Open
Abstract
Basic helix-loop-helix (bHLH) proteins are transcription factors (TFs) that have been shown to regulate anthocyanin biosynthesis in many plant species. However, the bHLH gene family in walnut (Juglans regia L.) has not yet been reported. In this study, 102 bHLH genes were identified in the walnut genome and were classified into 15 subfamilies according to sequence similarity and phylogenetic relationships. The gene structure, conserved domains, and chromosome location of the genes were analyzed by bioinformatic methods. Gene duplication analyses revealed that 42 JrbHLHs were involved in the expansion of the walnut bHLH gene family. We also characterized cis-regulatory elements of these genes and performed Gene Ontology enrichment analysis of gene functions, and examined protein-protein interactions. Four candidate genes (JrEGL1a, JrEGL1b, JrbHLHA1, and JrbHLHA2) were found to have high homology to genes encoding bHLH TFs involved in anthocyanin biosynthesis in other plants. RNA sequencing revealed tissue- and developmental stage-specific expression profiles and distinct expression patterns of JrbHLHs according to phenotype (red vs. green leaves) and developmental stage in red walnut hybrid progeny, which were confirmed by quantitative real-time PCR analysis. All four of the candidate JrbHLH proteins localized to the nucleus, consistent with a TF function. These results provide a basis for the functional characterization of bHLH genes and investigations on the molecular mechanisms of anthocyanin biosynthesis in red walnut.
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Affiliation(s)
- Wei Zhao
- College of Horticulture, Henan Agricultural University, Zhengzhou, China.,Henan Key Laboratory of Fruit and Cucurbit Biology, Zhengzhou, China
| | - Yonghui Liu
- College of Horticulture, Henan Agricultural University, Zhengzhou, China.,Henan Key Laboratory of Fruit and Cucurbit Biology, Zhengzhou, China
| | - Lin Li
- College of Horticulture, Henan Agricultural University, Zhengzhou, China.,Henan Key Laboratory of Fruit and Cucurbit Biology, Zhengzhou, China
| | - Haijun Meng
- College of Horticulture, Henan Agricultural University, Zhengzhou, China.,Henan Key Laboratory of Fruit and Cucurbit Biology, Zhengzhou, China
| | - Ying Yang
- College of Horticulture, Henan Agricultural University, Zhengzhou, China.,Henan Key Laboratory of Fruit and Cucurbit Biology, Zhengzhou, China
| | - Zhaobin Dong
- Shangluo Shengda Industrial Co., Ltd., Luonan, China
| | - Lei Wang
- College of Horticulture, Henan Agricultural University, Zhengzhou, China.,Henan Key Laboratory of Fruit and Cucurbit Biology, Zhengzhou, China
| | - Guoliang Wu
- College of Horticulture, Henan Agricultural University, Zhengzhou, China.,Henan Key Laboratory of Fruit and Cucurbit Biology, Zhengzhou, China
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13
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Lowenstein ED, Rusanova A, Stelzer J, Hernaiz-Llorens M, Schroer AE, Epifanova E, Bladt F, Isik EG, Buchert S, Jia S, Tarabykin V, Hernandez-Miranda LR. Olig3 regulates early cerebellar development. eLife 2021; 10:64684. [PMID: 33591268 PMCID: PMC7886330 DOI: 10.7554/elife.64684] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2020] [Accepted: 02/03/2021] [Indexed: 12/22/2022] Open
Abstract
The mature cerebellum controls motor skill precision and participates in other sophisticated brain functions that include learning, cognition, and speech. Different types of GABAergic and glutamatergic cerebellar neurons originate in temporal order from two progenitor niches, the ventricular zone and rhombic lip, which express the transcription factors Ptf1a and Atoh1, respectively. However, the molecular machinery required to specify the distinct neuronal types emanating from these progenitor zones is still unclear. Here, we uncover the transcription factor Olig3 as a major determinant in generating the earliest neuronal derivatives emanating from both progenitor zones in mice. In the rhombic lip, Olig3 regulates progenitor cell proliferation. In the ventricular zone, Olig3 safeguards Purkinje cell specification by curtailing the expression of Pax2, a transcription factor that suppresses the Purkinje cell differentiation program. Our work thus defines Olig3 as a key factor in early cerebellar development.
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Affiliation(s)
| | - Aleksandra Rusanova
- Institute for Cell Biology and Neurobiology, Charité Universitätsmedizin Berlin, Berlin, Germany.,Institute of Neuroscience, Lobachevsky University of Nizhny Novgorod, Nizhny Novgorod, Russian Federation
| | - Jonas Stelzer
- Institute for Cell Biology and Neurobiology, Charité Universitätsmedizin Berlin, Berlin, Germany
| | | | - Adrian E Schroer
- Institute for Cell Biology and Neurobiology, Charité Universitätsmedizin Berlin, Berlin, Germany
| | - Ekaterina Epifanova
- Institute for Cell Biology and Neurobiology, Charité Universitätsmedizin Berlin, Berlin, Germany.,Institute of Neuroscience, Lobachevsky University of Nizhny Novgorod, Nizhny Novgorod, Russian Federation
| | - Francesca Bladt
- Max-Delbrück-Centrum in the Helmholtz Association, Berlin, Germany
| | - Eser Göksu Isik
- Institute for Cell Biology and Neurobiology, Charité Universitätsmedizin Berlin, Berlin, Germany
| | - Sven Buchert
- Max-Delbrück-Centrum in the Helmholtz Association, Berlin, Germany
| | - Shiqi Jia
- Max-Delbrück-Centrum in the Helmholtz Association, Berlin, Germany.,The First Affiliated Hospital of Jinan University, Guangzhou province, Guangzhou, China
| | - Victor Tarabykin
- Institute for Cell Biology and Neurobiology, Charité Universitätsmedizin Berlin, Berlin, Germany.,Institute of Neuroscience, Lobachevsky University of Nizhny Novgorod, Nizhny Novgorod, Russian Federation
| | - Luis R Hernandez-Miranda
- Max-Delbrück-Centrum in the Helmholtz Association, Berlin, Germany.,Institute for Cell Biology and Neurobiology, Charité Universitätsmedizin Berlin, Berlin, Germany
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14
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Song M, Wang H, Wang Z, Huang H, Chen S, Ma H. Genome-Wide Characterization and Analysis of bHLH Transcription Factors Related to Anthocyanin Biosynthesis in Fig ( Ficus carica L.). Front Plant Sci 2021; 12:730692. [PMID: 34691109 PMCID: PMC8531510 DOI: 10.3389/fpls.2021.730692] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/25/2021] [Accepted: 09/03/2021] [Indexed: 05/14/2023]
Abstract
The basic helix-loop-helix (bHLH) transcription factor family is the second largest transcription factor family in plants, and participates in various plant growth and development processes. A total of 118 bHLH genes were identified from fig (Ficus carica L.) by whole-genome database search. Phylogenetic analysis with Arabidopsis homologs divided them into 25 subfamilies. Most of the bHLHs in each subfamily shared a similar gene structure and conserved motifs. Seventy-two bHLHs were found expressed at fragments per kilobase per million mapped (FPKM) > 10 in the fig fruit; among them, 15 bHLHs from eight subfamilies had FPKM > 100 in at least one sample. bHLH subfamilies had different expression patterns in the female flower tissue and peel during fig fruit development. Comparing green and purple peel mutants, 13 bHLH genes had a significantly different (≥ 2-fold) expression. Light deprivation resulted in 68 significantly upregulated and 22 downregulated bHLH genes in the peel of the fruit. Sixteen bHLH genes in subfamily III were selected by three sets of transcriptomic data as candidate genes related to anthocyanin synthesis. Interaction network prediction and yeast two-hybrid screening verified the interaction between FcbHLH42 and anthocyanin synthesis-related genes. The transient expression of FcbHLH42 in tobacco led to an apparent anthocyanin accumulation. Our results confirm the first fig bHLH gene involved in fruit color development, laying the foundation for an in-depth functional study on other FcbHLH genes in fig fruit quality formation, and contributing to our understanding of the evolution of bHLH genes in other horticulturally important Ficus species.
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Affiliation(s)
- Miaoyu Song
- College of Horticulture, China Agricultural University, Beijing, China
| | - Haomiao Wang
- College of Horticulture, China Agricultural University, Beijing, China
| | - Zhe Wang
- College of Horticulture, China Agricultural University, Beijing, China
| | - Hantang Huang
- College of Horticulture, China Agricultural University, Beijing, China
| | - Shangwu Chen
- College of Food Science and Nutritional Engineering, China Agricultural University, Beijing, China
| | - Huiqin Ma
- College of Horticulture, China Agricultural University, Beijing, China
- State Key Laboratory of Agrobiotechnology, China Agricultural University, Beijing, China
- *Correspondence: Huiqin Ma
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15
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Koch MS, Czemmel S, Lennartz F, Beyeler S, Rajaraman S, Przystal JM, Govindarajan P, Canjuga D, Neumann M, Rizzu P, Zwirner S, Hoetker MS, Zender L, Walter B, Tatagiba M, Raineteau O, Heutink P, Nahnsen S, Tabatabai G. Experimental glioma with high bHLH expression harbor increased replicative stress and are sensitive toward ATR inhibition. Neurooncol Adv 2020; 2:vdaa115. [PMID: 33134924 PMCID: PMC7592426 DOI: 10.1093/noajnl/vdaa115] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Background The overexpression of (basic)helix-loop-helix ((b)HLH) transcription factors (TFs) is frequent in malignant glioma. We investigated molecular effects upon disruption of the (b)HLH network by a dominant-negative variant of the E47 protein (dnE47). Our goal was to identify novel molecular subgroup-specific therapeutic strategies. Methods Glioma cell lines LN229, LNZ308, and GS-2/GS-9 were lentivirally transduced. Functional characterization included immunocytochemistry, immunoblots, cytotoxic, and clonogenic survival assays in vitro, and latency until neurological symptoms in vivo. Results of cap analysis gene expression and RNA-sequencing were further validated by immunoblot, flow cytometry, and functional assays in vitro. Results The induction of dnE47-RFP led to cytoplasmic sequestration of (b)HLH TFs and antiglioma activity in vitro and in vivo. Downstream molecular events, ie, alterations in transcription start site usage and in the transcriptome revealed enrichment of cancer-relevant pathways, particularly of the DNA damage response (DDR) pathway. Pharmacologic validation of this result using ataxia telangiectasia and Rad3 related (ATR) inhibition led to a significantly enhanced early and late apoptotic effect compared with temozolomide alone. Conclusions Gliomas overexpressing (b)HLH TFs are sensitive toward inhibition of the ATR kinase. The combination of ATR inhibition plus temozolomide or radiation therapy in this molecular subgroup are warranted.
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Affiliation(s)
- Marilin Sophia Koch
- Department of Neurology and Interdisciplinary Neuro-Oncology, Hertie Institute for Clinical Brain Research, University Hospital Tübingen, Eberhard Karls University Tübingen, Tübingen, Germany
| | - Stefan Czemmel
- Quantitative Biology Center (QBiC), Eberhard Karls University Tübingen, Tübingen, Germany
| | - Felix Lennartz
- Department of Neurology and Interdisciplinary Neuro-Oncology, Hertie Institute for Clinical Brain Research, University Hospital Tübingen, Eberhard Karls University Tübingen, Tübingen, Germany
| | - Sarah Beyeler
- Department of Neurology and Interdisciplinary Neuro-Oncology, Hertie Institute for Clinical Brain Research, University Hospital Tübingen, Eberhard Karls University Tübingen, Tübingen, Germany.,German Translational Cancer Consortium (DKTK), DKFZ partner site Tübingen, Tübingen, Germany
| | - Srinath Rajaraman
- Department of Neurology and Interdisciplinary Neuro-Oncology, Hertie Institute for Clinical Brain Research, University Hospital Tübingen, Eberhard Karls University Tübingen, Tübingen, Germany
| | - Justyna Magdalena Przystal
- Department of Neurology and Interdisciplinary Neuro-Oncology, Hertie Institute for Clinical Brain Research, University Hospital Tübingen, Eberhard Karls University Tübingen, Tübingen, Germany.,German Translational Cancer Consortium (DKTK), DKFZ partner site Tübingen, Tübingen, Germany
| | - Parameswari Govindarajan
- Department of Neurology and Interdisciplinary Neuro-Oncology, Hertie Institute for Clinical Brain Research, University Hospital Tübingen, Eberhard Karls University Tübingen, Tübingen, Germany
| | - Denis Canjuga
- Department of Neurology and Interdisciplinary Neuro-Oncology, Hertie Institute for Clinical Brain Research, University Hospital Tübingen, Eberhard Karls University Tübingen, Tübingen, Germany
| | - Manfred Neumann
- Department of Neurology and Interdisciplinary Neuro-Oncology, Hertie Institute for Clinical Brain Research, University Hospital Tübingen, Eberhard Karls University Tübingen, Tübingen, Germany
| | - Patrizia Rizzu
- German Center for Neurodegenerative Diseases (DZNE), German Center for Neurodegenerative Diseases, Tübingen, Germany
| | - Stefan Zwirner
- Department of Internal Medicine VIII, University Hospital Tübingen, Eberhard Karls University Tübingen, Tübingen, Germany
| | - Michael Stefan Hoetker
- Department of Internal Medicine I, University Hospital Tübingen, Eberhard Karls University Tübingen, Tübingen, Germany
| | - Lars Zender
- Department of Internal Medicine VIII, University Hospital Tübingen, Eberhard Karls University Tübingen, Tübingen, Germany.,German Translational Cancer Consortium (DKTK), DKFZ partner site Tübingen, Tübingen, Germany
| | - Bianca Walter
- Department of Neurology and Interdisciplinary Neuro-Oncology, Hertie Institute for Clinical Brain Research, University Hospital Tübingen, Eberhard Karls University Tübingen, Tübingen, Germany.,German Translational Cancer Consortium (DKTK), DKFZ partner site Tübingen, Tübingen, Germany
| | - Marcos Tatagiba
- Department of Neurosurgery, University Hospital Tübingen, Eberhard Karls University Tübingen, Tübingen, Germany
| | - Olivier Raineteau
- University of Lyon, Université Claude Bernard Lyon 1, Inserm, Stem Cell and Brain Research Institute U1208, Bron, France
| | - Peter Heutink
- German Center for Neurodegenerative Diseases (DZNE), German Center for Neurodegenerative Diseases, Tübingen, Germany
| | - Sven Nahnsen
- Quantitative Biology Center (QBiC), Eberhard Karls University Tübingen, Tübingen, Germany
| | - Ghazaleh Tabatabai
- Department of Neurology and Interdisciplinary Neuro-Oncology, Hertie Institute for Clinical Brain Research, University Hospital Tübingen, Eberhard Karls University Tübingen, Tübingen, Germany.,German Translational Cancer Consortium (DKTK), DKFZ partner site Tübingen, Tübingen, Germany
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16
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Qi Y, Zhou L, Han L, Zou H, Miao K, Wang Y. PsbHLH1, a novel transcription factor involved in regulating anthocyanin biosynthesis in tree peony (Paeonia suffruticosa). Plant Physiol Biochem 2020; 154:396-408. [PMID: 32645590 DOI: 10.1016/j.plaphy.2020.06.015] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/11/2020] [Revised: 05/12/2020] [Accepted: 06/09/2020] [Indexed: 06/11/2023]
Abstract
Flower color is one of the most important features of ornamental plants. Anthocyanin composition and concentration are usually closely related to flower color formation. The biosynthesis of anthocyanin is regulated by a series of structural genes and regulatory genes. The basic helix-loop-helix proteins (bHLHs) are considered as one of the key transcription factors known as the regulators of anthocyanin biosynthesis. However, the bHLH transcription factor family of tree peony (Paeonia suffruticosa) has not been systematically studied in previous studies, especially for the regulation of petal pigmentation. The aim of this study was to identify bHLH genes and unravel their underlying molecular mechanism involved in the regulation of anthocyanin biosynthesis in tree peony. Based on transcriptome profiling analysis, we identified three bHLHs candidate anthocyanin regulators, PsbHLH1, PsbHLH2, and PsbHLH3. PsbHLH1-3 were phylogenetically clustered in the IIIf bHLH subgroup, which is involved in anthocyanin biosynthesis in other plant species. In addition, three bHLH proteins were localized in the nucleus and displayed transcriptional activation activity in a yeast hybrid system. Through a series of functional experiments, we further demonstrated that PsbHLH1 could transcriptionally activate the expression of PsDFR and PsANS via directly binding to their promoters. These results laid a solid foundation to better understand the regulatory mechanisms of anthocyanin biosynthesis in P. suffruticosa and to benefit molecular breeding of tree peony cultivars with novel color.
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Affiliation(s)
- Yu Qi
- Key Laboratory of Tree Breeding and Cultivation of National Forestry and Grassland Administration, Research Institute of Forestry, Chinese Academy of Forestry, Beijing, 100091, China
| | - Lin Zhou
- Key Laboratory of Tree Breeding and Cultivation of National Forestry and Grassland Administration, Research Institute of Forestry, Chinese Academy of Forestry, Beijing, 100091, China
| | - Lulu Han
- Key Laboratory of Tree Breeding and Cultivation of National Forestry and Grassland Administration, Research Institute of Forestry, Chinese Academy of Forestry, Beijing, 100091, China
| | - Hongzhu Zou
- Key Laboratory of Tree Breeding and Cultivation of National Forestry and Grassland Administration, Research Institute of Forestry, Chinese Academy of Forestry, Beijing, 100091, China
| | - Kun Miao
- Key Laboratory of Tree Breeding and Cultivation of National Forestry and Grassland Administration, Research Institute of Forestry, Chinese Academy of Forestry, Beijing, 100091, China
| | - Yan Wang
- Key Laboratory of Tree Breeding and Cultivation of National Forestry and Grassland Administration, Research Institute of Forestry, Chinese Academy of Forestry, Beijing, 100091, China.
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17
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Aslam MZ, Lin X, Li X, Yang N, Chen L. Molecular Cloning and Functional Characterization of CpMYC2 and CpBHLH13 Transcription Factors from Wintersweet ( Chimonanthus praecox L.). Plants (Basel) 2020; 9:plants9060785. [PMID: 32585874 PMCID: PMC7356763 DOI: 10.3390/plants9060785] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/25/2020] [Revised: 06/17/2020] [Accepted: 06/19/2020] [Indexed: 02/06/2023]
Abstract
Wintersweet (Chimonanthus praecox L.) is an ornamental and economically significant shrub known for its unique flowering characteristics, especially the emission of abundant floral volatile organic compounds. Thus, an understanding of the molecular mechanism of the production of these compounds is necessary to create new breeds with high volatile production. In this study, two bHLH transcription factors (CpMYC2 and CpbHLH13) of Wintersweet H29 were functionally characterized to illustrate their possible role in the production of volatile compounds. The qRT-PCR results showed that the expression of CpMYC2 and CpbHLH13 increased from the flower budding to full bloom stage, indicating that these two genes may play an essential role in blooming and aroma production in wintersweet. Gas chromatography-mass spectroscopy (GC-MS) analysis revealed that the overexpression of CpMYC2 in arabidopsis (Arabidopsis thaliana) AtMYC2-2 mutant (Salk_083483) and tobacco (Nicotiana tabaccum) genotype Petit Havana SR1 significantly increased floral volatile monoterpene, especially linalool, while the overexpression of CpbHLH13 in Arabidopsis thaliana ecotype Columbia-0 (Col-0) and tobacco genotype SR1 increased floral sesquiterpene β-caryophyllene production in both types of transgenic plants respectively. High expression of terpene synthase (TPS) genes in transgenic A. thaliana along with high expression of CpMYC2 and CpbHLH13 in transgenic plants was also observed. The application of a combination of methyl jasmonic acid (MeJA) and gibberellic acid (GA3) showed an increment in linalool production in CpMYC2-overexpressing arabidopsis plants, and the high transcript level of TPS genes also suggested the involvement of CpMYC2 in the jasmonic acid (JA) signaling pathway. These results indicate that both the CpMYC2 and CpbHLH13 transcription factors of wintersweet are possibly involved in the positive regulation and biosynthesis of monoterpene (linalool) and sesquiterpene (β-caryophyllene) in transgenic plants. This study also indicates the potential application of wintersweet as a valuable genomic material for the genetic modification of floral scent in other flowering plants that produce less volatile compounds.
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Affiliation(s)
- Muhammad Zeshan Aslam
- Key Laboratory of Horticultural Plant Biology (Ministry of Education), College of Horticulture and Forestry Science, Huazhong Agricultural University, Wuhan 430070, China; (M.Z.A.); (X.L.); (X.L.)
| | - Xiang Lin
- Key Laboratory of Horticultural Plant Biology (Ministry of Education), College of Horticulture and Forestry Science, Huazhong Agricultural University, Wuhan 430070, China; (M.Z.A.); (X.L.); (X.L.)
| | - Xiang Li
- Key Laboratory of Horticultural Plant Biology (Ministry of Education), College of Horticulture and Forestry Science, Huazhong Agricultural University, Wuhan 430070, China; (M.Z.A.); (X.L.); (X.L.)
| | - Nan Yang
- Southwest Research Centre for Engineering Technology of Landscape Architecture (State Forestry and Grassland Administration), Southwest Forestry University, Kunming 650224, China;
| | - Longqing Chen
- Southwest Research Centre for Engineering Technology of Landscape Architecture (State Forestry and Grassland Administration), Southwest Forestry University, Kunming 650224, China;
- Correspondence:
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18
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Han S, Dennis DJ, Balakrishnan A, Dixit R, Britz O, Zinyk D, Touahri Y, Olender T, Brand M, Guillemot F, Kurrasch D, Schuurmans C. A non-canonical role for the proneural gene Neurog1 as a negative regulator of neocortical neurogenesis. Development 2018; 145:dev157719. [PMID: 30201687 PMCID: PMC6198467 DOI: 10.1242/dev.157719] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2017] [Accepted: 08/31/2018] [Indexed: 02/05/2023]
Abstract
Neural progenitors undergo temporal identity transitions to sequentially generate the neuronal and glial cells that make up the mature brain. Proneural genes have well-characterised roles in promoting neural cell differentiation and subtype specification, but they also regulate the timing of identity transitions through poorly understood mechanisms. Here, we investigated how the highly related proneural genes Neurog1 and Neurog2 interact to control the timing of neocortical neurogenesis. We found that Neurog1 acts in an atypical fashion as it is required to suppress rather than promote neuronal differentiation in early corticogenesis. In Neurog1-/- neocortices, early born neurons differentiate in excess, whereas, in vitro, Neurog1-/- progenitors have a decreased propensity to proliferate and form neurospheres. Instead, Neurog1-/- progenitors preferentially generate neurons, a phenotype restricted to the Neurog2+ progenitor pool. Mechanistically, Neurog1 and Neurog2 heterodimerise, and while Neurog1 and Neurog2 individually promote neurogenesis, misexpression together blocks this effect. Finally, Neurog1 is also required to induce the expression of neurogenic factors (Dll1 and Hes5) and to repress the expression of neuronal differentiation genes (Fezf2 and Neurod6). Neurog1 thus employs different mechanisms to temper the pace of early neocortical neurogenesis.
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Affiliation(s)
- Sisu Han
- Biological Sciences Platform, Sunnybrook Research Institute, Toronto, ON M4N 3M5, Canada
- Department of Biochemistry, University of Toronto, Toronto, ON M5S 1A8, Canada
| | - Daniel J Dennis
- Biological Sciences Platform, Sunnybrook Research Institute, Toronto, ON M4N 3M5, Canada
- Department of Biochemistry and Molecular Biology, Alberta Children's Hospital Research Institute, Hotchkiss Brain Institute, University of Calgary, Calgary, AB T2N 4N1, Canada
- Department of Molecular Genetics, Alberta Children's Hospital Research Institute, University of Calgary, Calgary, AB T2N 4N1, Canada
| | - Anjali Balakrishnan
- Biological Sciences Platform, Sunnybrook Research Institute, Toronto, ON M4N 3M5, Canada
- Department of Biochemistry, University of Toronto, Toronto, ON M5S 1A8, Canada
| | - Rajiv Dixit
- Biological Sciences Platform, Sunnybrook Research Institute, Toronto, ON M4N 3M5, Canada
| | - Olivier Britz
- The Francis Crick Institute-Mill Hill Laboratory, London NW7 1AA, UK
| | - Dawn Zinyk
- Biological Sciences Platform, Sunnybrook Research Institute, Toronto, ON M4N 3M5, Canada
| | - Yacine Touahri
- Biological Sciences Platform, Sunnybrook Research Institute, Toronto, ON M4N 3M5, Canada
| | - Thomas Olender
- Ottawa Hospital Research Institute, Ottawa, ON K1H 8L6, Canada
| | - Marjorie Brand
- Ottawa Hospital Research Institute, Ottawa, ON K1H 8L6, Canada
| | | | - Deborah Kurrasch
- Department of Molecular Genetics, Alberta Children's Hospital Research Institute, University of Calgary, Calgary, AB T2N 4N1, Canada
| | - Carol Schuurmans
- Biological Sciences Platform, Sunnybrook Research Institute, Toronto, ON M4N 3M5, Canada
- Department of Biochemistry, University of Toronto, Toronto, ON M5S 1A8, Canada
- Department of Biochemistry and Molecular Biology, Alberta Children's Hospital Research Institute, Hotchkiss Brain Institute, University of Calgary, Calgary, AB T2N 4N1, Canada
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Chu Y, Xiao S, Su H, Liao B, Zhang J, Xu J, Chen S. Genome-wide characterization and analysis of bHLH transcription factors in Panax ginseng. Acta Pharm Sin B 2018; 8:666-677. [PMID: 30109190 PMCID: PMC6089850 DOI: 10.1016/j.apsb.2018.04.004] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2018] [Revised: 02/24/2018] [Accepted: 03/14/2018] [Indexed: 11/24/2022] Open
Abstract
Ginseng (Panax ginseng C.A. Meyer) is one of the best-selling herbal medicines, with ginsenosides as its main pharmacologically active constituents. Although extensive chemical and pharmaceutical studies of these compounds have been performed, genome-wide studies of the basic helix-loop-helix (bHLH) transcription factors of ginseng are still limited. The bHLH transcription factor family is one of the largest transcription factor families found in eukaryotic organisms, and these proteins are involved in a myriad of regulatory processes. In our study, 169 bHLH transcription factor genes were identified in the genome of P. ginseng, and phylogenetic analysis indicated that these PGbHLHs could be classified into 24 subfamilies. A total of 21 RNA-seq data sets, including two sequencing libraries for jasmonate (JA)-responsive and 19 reported libraries for organ-specific expression analyses were constructed. Through a combination of gene-specific expression patterns and chemical contents, 6 PGbHLH genes from 4 subfamilies were revealed to be potentially involved in the regulation of ginsenoside biosynthesis. These 6 PGbHLHs, which had distinct target genes, were further divided into two groups depending on the absence of MYC-N structure. Our results would provide a foundation for understanding the molecular basis and regulatory mechanisms of bHLH transcription factor action in P. ginseng.
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Affiliation(s)
- Yang Chu
- Institute of Chinese Materia Medica, China Academy of Chinese Medical Sciences, Beijing 100700, China
| | - Shuiming Xiao
- Institute of Chinese Materia Medica, China Academy of Chinese Medical Sciences, Beijing 100700, China
| | - He Su
- Institute of Chinese Materia Medica, China Academy of Chinese Medical Sciences, Beijing 100700, China
- Guangdong Provincial Hospital of Chinese Medicine, Guangzhou 510006, China
| | - Baosheng Liao
- Institute of Chinese Materia Medica, China Academy of Chinese Medical Sciences, Beijing 100700, China
| | - Jingjing Zhang
- Institute of Chinese Materia Medica, China Academy of Chinese Medical Sciences, Beijing 100700, China
- College of Pharmacy, Hubei University of Chinese Medicine, Wuhan 430065, China
| | - Jiang Xu
- Institute of Chinese Materia Medica, China Academy of Chinese Medical Sciences, Beijing 100700, China
- Corresponding authors.
| | - Shilin Chen
- Institute of Chinese Materia Medica, China Academy of Chinese Medical Sciences, Beijing 100700, China
- Corresponding authors.
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20
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Dennis DJ, Han S, Schuurmans C. bHLH transcription factors in neural development, disease, and reprogramming. Brain Res 2018; 1705:48-65. [PMID: 29544733 DOI: 10.1016/j.brainres.2018.03.013] [Citation(s) in RCA: 117] [Impact Index Per Article: 19.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2017] [Revised: 03/07/2018] [Accepted: 03/10/2018] [Indexed: 01/16/2023]
Abstract
The formation of functional neural circuits in the vertebrate central nervous system (CNS) requires that appropriate numbers of the correct types of neuronal and glial cells are generated in their proper places and times during development. In the embryonic CNS, multipotent progenitor cells first acquire regional identities, and then undergo precisely choreographed temporal identity transitions (i.e. time-dependent changes in their identity) that determine how many neuronal and glial cells of each type they will generate. Transcription factors of the basic-helix-loop-helix (bHLH) family have emerged as key determinants of neural cell fate specification and differentiation, ensuring that appropriate numbers of specific neuronal and glial cell types are produced. Recent studies have further revealed that the functions of these bHLH factors are strictly regulated. Given their essential developmental roles, it is not surprising that bHLH mutations and de-regulated expression are associated with various neurological diseases and cancers. Moreover, the powerful ability of bHLH factors to direct neuronal and glial cell fate specification and differentiation has been exploited in the relatively new field of cellular reprogramming, in which pluripotent stem cells or somatic stem cells are converted to neural lineages, often with a transcription factor-based lineage conversion strategy that includes one or more of the bHLH genes. These concepts are reviewed herein.
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Affiliation(s)
- Daniel J Dennis
- Sunnybrook Research Institute, 2075 Bayview Ave, Toronto, ON M4N3M5, Canada
| | - Sisu Han
- Sunnybrook Research Institute, 2075 Bayview Ave, Toronto, ON M4N3M5, Canada; Department of Biochemistry, University of Toronto, Toronto, ON, Canada
| | - Carol Schuurmans
- Sunnybrook Research Institute, 2075 Bayview Ave, Toronto, ON M4N3M5, Canada; Department of Biochemistry, University of Toronto, Toronto, ON, Canada.
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21
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Mertens J, Van Moerkercke A, Vanden Bossche R, Pollier J, Goossens A. Clade IVa Basic Helix-Loop-Helix Transcription Factors Form Part of a Conserved Jasmonate Signaling Circuit for the Regulation of Bioactive Plant Terpenoid Biosynthesis. Plant Cell Physiol 2016; 57:2564-2575. [PMID: 27694525 DOI: 10.1093/pcp/pcw168] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/24/2016] [Accepted: 09/23/2016] [Indexed: 05/18/2023]
Abstract
Plants produce many bioactive, specialized metabolites to defend themselves when facing various stress situations. Their biosynthesis is directed by a tightly controlled regulatory circuit that is elicited by phytohormones such as jasmonate (JA). The basic helix-loop-helix (bHLH) transcription factors (TFs) bHLH iridoid synthesis 1 (BIS1) and Triterpene Saponin Activating Regulator (TSAR) 1 and 2, from Catharanthus roseus and Medicago truncatula, respectively, all belong to clade IVa of the bHLH protein family and activate distinct terpenoid pathways, thereby mediating monoterpenoid indole alkaloid (MIA) and triterpene saponin (TS) accumulation, respectively, in these two species. In this study, we report that promoters of the genes encoding the enzymes involved in the specific terpenoid pathway of one of these species can be transactivated by the orthologous bHLH factor from the other species through recognition of the same cis-regulatory elements. Accordingly, ectopic expression of CrBIS1 in M. truncatula hairy roots up-regulated the expression of all genes required for soyasaponin production, resulting in strongly increased levels of soyasaponins in the transformed roots. Likewise, transient expression of MtTSAR1 and MtTSAR2 in C. roseus petals led to up-regulation of the genes involved in the iridoid branch of the MIA pathway. Together, our data illustrate the functional similarity of these JA-inducible TFs and indicate that recruitment of defined cis-regulatory elements constitutes an important aspect of the evolution of conserved regulatory modules for the activation of species-specific terpenoid biosynthesis pathways by common signals such as the JA phytohormones.
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Affiliation(s)
- Jan Mertens
- Department of Plant Systems Biology, VIB, B-9052 Gent, Belgium
- Department of Plant Biotechnology and Bioinformatics, Ghent University, B-9052 Gent, Belgium
- These authors contributed equally to this work
| | - Alex Van Moerkercke
- Department of Plant Systems Biology, VIB, B-9052 Gent, Belgium
- Department of Plant Biotechnology and Bioinformatics, Ghent University, B-9052 Gent, Belgium
- These authors contributed equally to this work
| | - Robin Vanden Bossche
- Department of Plant Systems Biology, VIB, B-9052 Gent, Belgium
- Department of Plant Biotechnology and Bioinformatics, Ghent University, B-9052 Gent, Belgium
| | - Jacob Pollier
- Department of Plant Systems Biology, VIB, B-9052 Gent, Belgium
- Department of Plant Biotechnology and Bioinformatics, Ghent University, B-9052 Gent, Belgium
| | - Alain Goossens
- Department of Plant Systems Biology, VIB, B-9052 Gent, Belgium
- Department of Plant Biotechnology and Bioinformatics, Ghent University, B-9052 Gent, Belgium
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22
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Pruszko M, Żylicz A. [ID proteins in tumour initiation and progression]. Postepy Biochem 2016; 62:449-458. [PMID: 28132447] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2016] [Accepted: 07/28/2016] [Indexed: 06/06/2023]
Abstract
Despite decades of cancer research, the search for key oncogenesis regulators as potential targets for novel therapies continues. Proteins, belonging to ID family, may be such promising candidates. They are DNA binding inhibitors, mainly of the bHLH transcription factor subfamily, which regulate genes related to cell differentiation. ID genes are normally expressed in progenitor and stem cells inhibiting their differentiation. Nevertheless, in some cases the expression of ID genes was observed to direct cell maturation process. In tumors ID proteins manifest hallmarks of both oncogenes and tumor suppressors, depending on the affected organ. As a consequence of deregulated signaling pathways occurring in cancers, ID genes may be overexpressed or silenced. In effect, abnormal levels of ID proteins invariably lead to dedifferentiation of cancer cells and give them the characteristics of stem cells, such as the ability for self-renewal, avoidance of apoptosis and senescence. Moreover, ID proteins take part in metastasis and angiogenesis. The involvement of ID proteins in carcinogenesis encourages to further investigate their mechanisms of action and implement this knowledge in the design of new drugs.
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Affiliation(s)
- Magdalena Pruszko
- International Institute of Molecular and Cell Biology in Warsaw, 4 Ksiecia Trojdena St., 02-109 Warsaw, Poland
- Institute of Biochemistry and Biophysics, Polish Academy of Sciences, 5a Pawinskiego St., 02-106 Warszawa, Poland
| | - Alicja Żylicz
- International Institute of Molecular and Cell Biology in Warsaw, 4 Ksiecia Trojdena St., 02-109 Warsaw, Poland
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23
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Pfeiffer A, Shi H, Tepperman JM, Zhang Y, Quail PH. Combinatorial complexity in a transcriptionally centered signaling hub in Arabidopsis. Mol Plant 2014; 7:1598-1618. [PMID: 25122696 PMCID: PMC4587546 DOI: 10.1093/mp/ssu087] [Citation(s) in RCA: 130] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/06/2014] [Accepted: 07/29/2014] [Indexed: 05/18/2023]
Abstract
A subfamily of four Phytochrome (phy)-Interacting bHLH transcription Factors (PIFs) collectively promote skotomorphogenic development in dark-grown seedlings. This activity is reversed upon exposure to light, by photoactivated phy molecules that induce degradation of the PIFs, thereby triggering the transcriptional changes that drive a transition to photomorphogenesis. The PIFs function both redundantly and partially differentially at the morphogenic level in this process. To identify the direct targets of PIF transcriptional regulation genome-wide, we analyzed the DNA-binding sites for all four PIFs by ChIP-seq analysis, and defined the genes transcriptionally regulated by each PIF, using RNA-seq analysis of pif mutants. Despite the absence of detectable differences in DNA-binding-motif recognition between the PIFs, the data show a spectrum of regulatory patterns, ranging from single PIF dominance to equal contributions by all four. Similarly, a broad array of promoter architectures was found, ranging from single PIF-binding sites, containing single sequence motifs, through multiple PIF-binding sites, each containing one or more motifs, with each site occupied preferentially by one to multiple PIFs. Quantitative analysis of the promoter occupancy and expression level induced by each PIF revealed an intriguing pattern. Although there is no robust correlation broadly across the target-gene population, examination of individual genes that are shared targets of multiple PIFs shows a gradation in correlation from strongly positive, through uncorrelated, to negative. This finding suggests a dual-layered mechanism of transcriptional regulation, comprising both a continuum of binding-site occupancy by each PIF and a superimposed layer of local regulation that acts differentially on each PIF, to modulate its intrinsic transcriptional activation capacity at each site, in a quantitative pattern that varies between the individual PIFs from gene to gene. These findings provide a framework for probing the mechanisms by which transcription factors with overlapping direct-target genes integrate and selectively transduce signals to their target networks.
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Affiliation(s)
- Anne Pfeiffer
- Department of Plant and Microbial Biology, University of California, Berkeley, CA 94720, USA; United States Department of Agriculture, Plant Gene Expression Center, Albany, CA 94710, USA
| | - Hui Shi
- Department of Plant and Microbial Biology, University of California, Berkeley, CA 94720, USA; United States Department of Agriculture, Plant Gene Expression Center, Albany, CA 94710, USA
| | - James M Tepperman
- Department of Plant and Microbial Biology, University of California, Berkeley, CA 94720, USA; United States Department of Agriculture, Plant Gene Expression Center, Albany, CA 94710, USA
| | - Yu Zhang
- Department of Plant and Microbial Biology, University of California, Berkeley, CA 94720, USA; United States Department of Agriculture, Plant Gene Expression Center, Albany, CA 94710, USA
| | - Peter H Quail
- Department of Plant and Microbial Biology, University of California, Berkeley, CA 94720, USA; United States Department of Agriculture, Plant Gene Expression Center, Albany, CA 94710, USA.
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24
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Davies KA, Bergmann DC. Functional specialization of stomatal bHLHs through modification of DNA-binding and phosphoregulation potential. Proc Natl Acad Sci U S A 2014; 111:15585-90. [PMID: 25304637 DOI: 10.1073/pnas.1411766111] [Citation(s) in RCA: 53] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
Abstract
Transcription factor duplication events and subsequent specialization can drive evolution by facilitating biological innovation and developmental complexity. Identification of sequences that confer distinct biochemical function in vivo is an important step in understanding how related factors could refine specific developmental processes over time. Functional analysis of the basic helix-loop-helix (bHLH) protein SPEECHLESS, one of three closely related transcription factors required for stomatal lineage progression in Arabidopsis thaliana, allowed a dissection of motifs associated with specific developmental outputs. Phosphorylated residues, shown previously to quantitatively affect activity, also allow a qualitative shift in function between division and cell fate-promoting activities. Our data also provide surprising evidence that, despite deep sequence conservation in DNA-binding domains, the functional requirement for these domains has diverged, with the three stomatal bHLHs exhibiting absolute, partial, or no requirements for DNA-binding residues for their in vivo activities. Using these data, we build a plausible model describing how the current unique and overlapping roles of these proteins might have evolved from a single ancestral protein.
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25
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Li S, Mattar P, Dixit R, Lawn SO, Wilkinson G, Kinch C, Eisenstat D, Kurrasch DM, Chan JA, Schuurmans C. RAS/ERK signaling controls proneural genetic programs in cortical development and gliomagenesis. J Neurosci 2014; 34:2169-90. [PMID: 24501358 DOI: 10.1523/JNEUROSCI.4077-13.2014] [Citation(s) in RCA: 75] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Neural cell fate specification is well understood in the embryonic cerebral cortex, where the proneural genes Neurog2 and Ascl1 are key cell fate determinants. What is less well understood is how cellular diversity is generated in brain tumors. Gliomas and glioneuronal tumors, which are often localized in the cerebrum, are both characterized by a neoplastic glial component, but glioneuronal tumors also have an intermixed neuronal component. A core abnormality in both tumor groups is overactive RAS/ERK signaling, a pro-proliferative signal whose contributions to cell differentiation in oncogenesis are largely unexplored. We found that RAS/ERK activation levels differ in two distinct human tumors associated with constitutively active BRAF. Pilocytic astrocytomas, which contain abnormal glial cells, have higher ERK activation levels than gangliogliomas, which contain abnormal neuronal and glial cells. Using in vivo gain of function and loss of function in the mouse embryonic neocortex, we found that RAS/ERK signals control a proneural genetic switch, inhibiting Neurog2 expression while inducing Ascl1, a competing lineage determinant. Furthermore, we found that RAS/ERK levels control Ascl1's fate specification properties in murine cortical progenitors--at higher RAS/ERK levels, Ascl1(+) progenitors are biased toward proliferative glial programs, initiating astrocytomas, while at moderate RAS/ERK levels, Ascl1 promotes GABAergic neuronal and less glial differentiation, generating glioneuronal tumors. Mechanistically, Ascl1 is phosphorylated by ERK, and ERK phosphoacceptor sites are necessary for Ascl1's GABAergic neuronal and gliogenic potential. RAS/ERK signaling thus acts as a rheostat to influence neural cell fate selection in both normal cortical development and gliomagenesis, controlling Neurog2-Ascl1 expression and Ascl1 function.
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26
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Fan H, Zhang Z, Wang N, Cui Y, Sun H, Liu Y, Wu H, Zheng S, Bao S, Ling HQ. SKB1/PRMT5-mediated histone H4R3 dimethylation of Ib subgroup bHLH genes negatively regulates iron homeostasis in Arabidopsis thaliana. Plant J 2014; 77:209-21. [PMID: 24298997 DOI: 10.1111/tpj.12380] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/18/2013] [Revised: 10/26/2013] [Accepted: 11/04/2013] [Indexed: 05/21/2023]
Abstract
Histone modifications play critical roles in the perception of environmental cues by plants. Here, we report that Shk1 binding protein 1 (SKB1/AtPRMT5), which catalyzes the symmetric dimethylation of histone H4R3 (H4R3sme2), is involved in iron homeostasis in Arabidopsis. The SKB1 lesion mutant exhibited higher iron accumulation in shoots and greater tolerance to iron deficiency than the wild type. The expression of SKB1 was not affected by iron, but the level of H4R3sme2 mediated by SKB1 was related to iron status in plants. We showed by chromatin immunoprecipitation (ChIP) and genome-wide ChIP-seq that SKB1 associated with the chromatin of the Ib subgroup bHLH genes (AtbHLH38, AtbHLH39, AtbHLH100 and AtbHLH101), and symmetrically dimethylated histone H4R3. The quantity of SKB1 that associated with chromatin of the Ib subgroup bHLH genes and the level of H4R3sme2 corresponded to the iron status of plants (higher with increased iron supply and lower when iron was removed). We conclude that SKB1-mediated H4R3sme2 regulates iron homeostasis in Arabidopsis in the context of increasing or decreasing expression of Ib subgroup bHLH genes. Iron deficiency may cause an increase in the disassociation of SKB1 from chromatin of the bHLH genes and a decrease in the level of H4R3sme2, thereby elevating their transcription and enhancing iron uptake. Our findings provide new insight into the molecular mechanisms of iron homeostasis in strategy I plants.
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Affiliation(s)
- Huajie Fan
- State Key Laboratory of Plant Cell and Chromosome Engineering, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, No. 1 West Beichen Road, Chaoyang District, Beijing, 100101, China
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Carabelli M, Turchi L, Ruzza V, Morelli G, Ruberti I. Homeodomain-Leucine Zipper II family of transcription factors to the limelight: central regulators of plant development. Plant Signal Behav 2013; 8:25447. [PMID: 23838958 PMCID: PMC4002598 DOI: 10.4161/psb.25447] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/13/2013] [Accepted: 06/18/2013] [Indexed: 05/20/2023]
Abstract
The Arabidopsis genome encodes 10 Homeodomain-Leucine Zipper (HD-Zip) II transcription factors that can be subdivided into 4 clades (α-δ). All the γ (ARABIDOPSIS THALIANA HOMEOBOX 2 [ATHB2], HOMEOBOX ARABIDOPSIS THALIANA 1 [HAT1], HAT2) and δ (HAT3, ATHB4) genes are regulated by light quality changes (Low Red [R]/Far-Red [FR]) that induce the shade avoidance response in most of the angiosperms. HD-Zip IIγ and HD-Zip IIδ transcription factors function as positive regulators of shade avoidance, and there is evidence that at least ATHB2 is directly positively regulated by the basic Helix-Loop-Helix (bHLH) proteins PHYTOCHROME INTERACTING FACTOR 4 (PIF4) and PIF5. Recent evidence demonstrate that, in addition to their function in shade avoidance, HD-Zip IIγ and HD-Zip IIδ proteins play an essential role in plant development from embryogenesis onwards in a white light environment.
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Affiliation(s)
- Monica Carabelli
- Institute of Molecular Biology and Pathology; National Research Council; Rome, Italy
| | - Luana Turchi
- Institute of Molecular Biology and Pathology; National Research Council; Rome, Italy
| | - Valentino Ruzza
- Institute of Molecular Biology and Pathology; National Research Council; Rome, Italy
| | - Giorgio Morelli
- Food and Nutrition Research Centre; Agricultural Research Council (CRA); Rome, Italy
| | - Ida Ruberti
- Institute of Molecular Biology and Pathology; National Research Council; Rome, Italy
- Correspondence to: Ida Ruberti,
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