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1.
Mol Cell ; 84(17): 3223-3236.e4, 2024 Sep 05.
Artigo em Inglês | MEDLINE | ID: mdl-39094566

RESUMO

Chromatin-based epigenetic memory relies on the symmetric distribution of parental histones to newly synthesized daughter DNA strands, aided by histone chaperones within the DNA replication machinery. However, the mechanism of parental histone transfer remains elusive. Here, we reveal that in fission yeast, the replisome protein Mrc1 plays a crucial role in promoting the transfer of parental histone H3-H4 to the lagging strand, ensuring proper heterochromatin inheritance. In addition, Mrc1 facilitates the interaction between Mcm2 and DNA polymerase alpha, two histone-binding proteins critical for parental histone transfer. Furthermore, Mrc1's involvement in parental histone transfer and epigenetic inheritance is independent of its known functions in DNA replication checkpoint activation and replisome speed control. Instead, Mrc1 interacts with Mcm2 outside of its histone-binding region, creating a physical barrier to separate parental histone transfer pathways. These findings unveil Mrc1 as a key player within the replisome, coordinating parental histone segregation to regulate epigenetic inheritance.


Assuntos
Replicação do DNA , Epigênese Genética , Histonas , Proteínas de Schizosaccharomyces pombe , Schizosaccharomyces , Proteínas de Ciclo Celular/metabolismo , Proteínas de Ciclo Celular/genética , DNA Polimerase I/metabolismo , DNA Polimerase I/genética , Heterocromatina/metabolismo , Heterocromatina/genética , Histonas/metabolismo , Histonas/genética , Ligação Proteica , Schizosaccharomyces/genética , Schizosaccharomyces/metabolismo , Proteínas de Schizosaccharomyces pombe/metabolismo , Proteínas de Schizosaccharomyces pombe/genética
2.
Genes Dev ; 38(3-4): 189-204, 2024 03 22.
Artigo em Inglês | MEDLINE | ID: mdl-38479839

RESUMO

Chromatin-based epigenetic memory relies on the accurate distribution of parental histone H3-H4 tetramers to newly replicated DNA strands. Mcm2, a subunit of the replicative helicase, and Dpb3/4, subunits of DNA polymerase ε, govern parental histone H3-H4 deposition to the lagging and leading strands, respectively. However, their contribution to epigenetic inheritance remains controversial. Here, using fission yeast heterochromatin inheritance systems that eliminate interference from initiation pathways, we show that a Mcm2 histone binding mutation severely disrupts heterochromatin inheritance, while mutations in Dpb3/4 cause only moderate defects. Surprisingly, simultaneous mutations of Mcm2 and Dpb3/4 stabilize heterochromatin inheritance. eSPAN (enrichment and sequencing of protein-associated nascent DNA) analyses confirmed the conservation of Mcm2 and Dpb3/4 functions in parental histone H3-H4 segregation, with their combined absence showing a more symmetric distribution of parental histone H3-H4 than either single mutation alone. Furthermore, the FACT histone chaperone regulates parental histone transfer to both strands and collaborates with Mcm2 and Dpb3/4 to maintain parental histone H3-H4 density and faithful heterochromatin inheritance. These results underscore the importance of both symmetric distribution of parental histones and their density at daughter strands for epigenetic inheritance and unveil distinctive properties of parental histone chaperones during DNA replication.


Assuntos
Histonas , Schizosaccharomyces , Histonas/metabolismo , Chaperonas de Histonas/genética , Chaperonas de Histonas/metabolismo , Heterocromatina/genética , Replicação do DNA/genética , DNA/metabolismo , Schizosaccharomyces/genética , Schizosaccharomyces/metabolismo , Epigênese Genética
3.
Genes Dev ; 33(1-2): 116-126, 2019 01 01.
Artigo em Inglês | MEDLINE | ID: mdl-30573453

RESUMO

Heterochromatin is a highly condensed form of chromatin that silences gene transcription. Although high levels of transcriptional activities disrupt heterochromatin, transcription of repetitive DNA elements and subsequent processing of the transcripts by the RNAi machinery are required for heterochromatin assembly. In fission yeast, a JmjC domain protein, Epe1, promotes transcription of DNA repeats to facilitate heterochromatin formation, but overexpression of Epe1 leads to heterochromatin defects. However, the molecular function of Epe1 is not well understood. By screening the fission yeast deletion library, we found that heterochromatin defects associated with Epe1 overexpression are alleviated by mutations of the SAGA histone acetyltransferase complex. Overexpressed Epe1 associates with SAGA and recruits SAGA to heterochromatin regions, which leads to increased histone acetylation, transcription of repeats, and the disruption of heterochromatin. At its normal expression levels, Epe1 also associates with SAGA, albeit weakly. Such interaction regulates histone acetylation levels at heterochromatin and promotes transcription of repeats for heterochromatin assembly. Our results also suggest that increases of certain chromatin protein levels, which frequently occur in cancer cells, might strengthen relatively weak interactions to affect the epigenetic landscape.


Assuntos
Regulação Fúngica da Expressão Gênica/genética , Heterocromatina/genética , Proteínas Nucleares/genética , Proteínas Nucleares/metabolismo , Proteínas de Schizosaccharomyces pombe/genética , Proteínas de Schizosaccharomyces pombe/metabolismo , Schizosaccharomyces/genética , Schizosaccharomyces/metabolismo , Acetilação , Montagem e Desmontagem da Cromatina/genética , Instabilidade Cromossômica/genética , Deleção de Genes , Heterocromatina/metabolismo , Heterocromatina/patologia , Histona Acetiltransferases/genética , Histona Acetiltransferases/metabolismo , Repetições de Microssatélites/genética , Transporte Proteico
4.
Nucleic Acids Res ; 52(5): 2372-2388, 2024 Mar 21.
Artigo em Inglês | MEDLINE | ID: mdl-38214234

RESUMO

Pediatric high-grade gliomas (pHGG) are devastating and incurable brain tumors with recurrent mutations in histone H3.3. These mutations promote oncogenesis by dysregulating gene expression through alterations of histone modifications. We identify aberrant DNA repair as an independent mechanism, which fosters genome instability in H3.3 mutant pHGG, and opens new therapeutic options. The two most frequent H3.3 mutations in pHGG, K27M and G34R, drive aberrant repair of replication-associated damage by non-homologous end joining (NHEJ). Aberrant NHEJ is mediated by the DNA repair enzyme polynucleotide kinase 3'-phosphatase (PNKP), which shows increased association with mutant H3.3 at damaged replication forks. PNKP sustains the proliferation of cells bearing H3.3 mutations, thus conferring a molecular vulnerability, specific to mutant cells, with potential for therapeutic targeting.


Assuntos
Neoplasias Encefálicas , Glioma , Histonas , Criança , Humanos , Neoplasias Encefálicas/patologia , Reparo do DNA/genética , Enzimas Reparadoras do DNA/metabolismo , Glioma/patologia , Histonas/genética , Histonas/metabolismo , Mutação , Fosfotransferases (Aceptor do Grupo Álcool)/genética
5.
PLoS Genet ; 18(2): e1010049, 2022 02.
Artigo em Inglês | MEDLINE | ID: mdl-35171902

RESUMO

The epigenetic landscape of a cell frequently changes in response to fluctuations in nutrient levels, but the mechanistic link is not well understood. In fission yeast, the JmjC domain protein Epe1 is critical for maintaining the heterochromatin landscape. While loss of Epe1 results in heterochromatin expansion, overexpression of Epe1 leads to defective heterochromatin. Through a genetic screen, we found that mutations in genes of the cAMP signaling pathway suppress the heterochromatin defects associated with Epe1 overexpression. We further demonstrated that the activation of Pka1, the downstream effector of cAMP signaling, is required for the efficient translation of epe1+ mRNA to maintain Epe1 overexpression. Moreover, inactivation of the cAMP-signaling pathway, either through genetic mutations or glucose deprivation, leads to the reduction of endogenous Epe1 and corresponding heterochromatin changes. These results reveal the mechanism by which the cAMP signaling pathway regulates heterochromatin landscape in fission yeast.


Assuntos
Proteínas de Schizosaccharomyces pombe , Schizosaccharomyces , Heterocromatina/genética , Heterocromatina/metabolismo , Histonas/genética , Proteínas Nucleares/genética , Schizosaccharomyces/genética , Schizosaccharomyces/metabolismo , Proteínas de Schizosaccharomyces pombe/genética , Proteínas de Schizosaccharomyces pombe/metabolismo , Transdução de Sinais/genética
6.
Yeast ; 41(1-2): 19-34, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-38041528

RESUMO

Genetic targeting (e.g., gene knockout and tagging) based on polymerase chain reaction (PCR) is a simple yet powerful approach for studying gene functions. Although originally developed in classic budding and fission yeast models, the same principle applies to other eukaryotic systems with efficient homologous recombination. One-step PCR-based genetic targeting is conventionally used but the sizes of the homologous arms that it generates for recombination-mediated genetic targeting are usually limited. Alternatively, gene targeting can also be performed via fusion PCR, which can create homologous arms that are orders of magnitude larger, therefore substantially increasing the efficiency of recombination-mediated genetic targeting. Here, we present GetPrimers (https://www.evomicslab.org/app/getprimers/), a generalized computational framework and web tool to assist automatic targeting and verification primer design for both one-step PCR-based and fusion PCR-based genetic targeting experiments. Moreover, GetPrimers by design runs for any given genetic background of any species with full genome scalability. Therefore, GetPrimers is capable of empowering high-throughput functional genomic assays at multipopulation and multispecies levels. Comprehensive experimental validations have been performed for targeting and verification primers designed by GetPrimers across multiple organism systems and experimental setups. We anticipate GetPrimers to become a highly useful and popular tool to facilitate easy and standardized gene modification across multiple systems.


Assuntos
Marcação de Genes , Schizosaccharomyces , Recombinação Homóloga , Técnicas de Inativação de Genes , Sequência de Bases , Schizosaccharomyces/genética , Reação em Cadeia da Polimerase
7.
Biology (Basel) ; 13(2)2024 Jan 28.
Artigo em Inglês | MEDLINE | ID: mdl-38392300

RESUMO

Accurate determination of protein localization, levels, or protein-protein interactions is pivotal for the study of their function, and in situ protein labeling via homologous recombination has emerged as a critical tool in many organisms. While this approach has been refined in various model fungi, the study of protein function in most plant pathogens has predominantly relied on ex situ or overexpression manipulations. To dissect the molecular mechanisms of development and infection for Verticillium dahliae, a formidable plant pathogen responsible for vascular wilt diseases, we have established a robust, homologous recombination-based in situ protein labeling strategy in this organism. Utilizing Agrobacterium tumefaciens-mediated transformation (ATMT), this methodology facilitates the precise tagging of specific proteins at their C-termini with epitopes, such as GFP and Flag, within the native context of V. dahliae. We demonstrate the efficacy of our approach through the in situ labeling of VdCf2 and VdDMM2, followed by subsequent confirmation via subcellular localization and protein-level analyses. Our findings confirm the applicability of homologous recombination for in situ protein labeling in V. dahliae and suggest its potential utility across a broad spectrum of filamentous fungi. This labeling method stands to significantly advance the field of functional genomics in plant pathogenic fungi, offering a versatile and powerful tool for the elucidation of protein function.

8.
Plant Cell ; 22(7): 2322-35, 2010 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-20622149

RESUMO

The production and distribution of plant trichomes is temporally and spatially regulated. After entering into the flowering stage, Arabidopsis thaliana plants have progressively reduced numbers of trichomes on the inflorescence stem, and the floral organs are nearly glabrous. We show here that SQUAMOSA PROMOTER BINDING PROTEIN LIKE (SPL) genes, which define an endogenous flowering pathway and are targeted by microRNA 156 (miR156), temporally control the trichome distribution during flowering. Plants overexpressing miR156 developed ectopic trichomes on the stem and floral organs. By contrast, plants with elevated levels of SPLs produced fewer trichomes. During plant development, the increase in SPL transcript levels is coordinated with the gradual loss of trichome cells on the stem. The MYB transcription factor genes TRICHOMELESS1 (TCL1) and TRIPTYCHON (TRY) are negative regulators of trichome development. We show that SPL9 directly activates TCL1 and TRY expression through binding to their promoters and that this activation is independent of GLABROUS1 (GL1). The phytohormones cytokinin and gibberellin were reported to induce trichome formation on the stem and inflorescence via the C2H2 transcription factors GIS, GIS2, and ZFP8, which promote GL1 expression. We show that the GIS-dependent pathway does not affect the regulation of TCL1 and TRY by miR156-targeted SPLs, represented by SPL9. These results demonstrate that the miR156-regulated SPLs establish a direct link between developmental programming and trichome distribution.


Assuntos
Arabidopsis/genética , Genes de Plantas , MicroRNAs/genética , Regiões Promotoras Genéticas
9.
FEBS J ; 290(2): 310-320, 2023 01.
Artigo em Inglês | MEDLINE | ID: mdl-34726351

RESUMO

Post-translational modifications in histones play important roles in regulating chromatin structure and gene expression programs, and the modified histones can be passed on to subsequent generations as an epigenetic memory. The fission yeast has been a great model organism for studying histone modifications in heterochromatin assembly and epigenetic inheritance. Here, we review findings in this organism that cemented the idea of chromatin-based inheritance and highlight recent studies that reveal the role of histone turnover in regulating this process.


Assuntos
Proteínas de Schizosaccharomyces pombe , Schizosaccharomyces , Histonas/metabolismo , Proteínas de Schizosaccharomyces pombe/genética , Heterocromatina/genética , Heterocromatina/metabolismo , Epigênese Genética , Cromatina/genética , Cromatina/metabolismo , Schizosaccharomyces/genética , Schizosaccharomyces/metabolismo
10.
Sci China Life Sci ; 65(11): 2162-2190, 2022 11.
Artigo em Inglês | MEDLINE | ID: mdl-35792957

RESUMO

Multi-cellular organisms such as humans contain hundreds of cell types that share the same genetic information (DNA sequences), and yet have different cellular traits and functions. While how genetic information is passed through generations has been extensively characterized, it remains largely obscure how epigenetic information encoded by chromatin regulates the passage of certain traits, gene expression states and cell identity during mitotic cell divisions, and even through meiosis. In this review, we will summarize the recent advances on molecular mechanisms of epigenetic inheritance, discuss the potential impacts of epigenetic inheritance during normal development and in some disease conditions, and outline future research directions for this challenging, but exciting field.


Assuntos
Cromatina , Epigênese Genética , Humanos , Cromatina/genética , Padrões de Herança/genética , Epigenômica , Fenótipo , Metilação de DNA
11.
Cell Rep ; 35(7): 109137, 2021 05 18.
Artigo em Inglês | MEDLINE | ID: mdl-34010645

RESUMO

Oncogenic histone lysine-to-methionine mutations block the methylation of their corresponding lysine residues on wild-type histones. One attractive model is that these mutations sequester histone methyltransferases, but genome-wide studies show that mutant histones and histone methyltransferases often do not colocalize. Using chromatin immunoprecipitation sequencing (ChIP-seq), here, we show that, in fission yeast, even though H3K9M-containing nucleosomes are broadly distributed across the genome, the histone H3K9 methyltransferase Clr4 is mainly sequestered at pericentric repeats. This selective sequestration of Clr4 depends not only on H3K9M but also on H3K14 ubiquitylation (H3K14ub), a modification deposited by a Clr4-associated E3 ubiquitin ligase complex. In vitro, H3K14ub synergizes with H3K9M to interact with Clr4 and potentiates the inhibitory effects of H3K9M on Clr4 enzymatic activity. Moreover, binding kinetics show that H3K14ub overcomes the Clr4 aversion to H3K9M and reduces its dissociation. The selective sequestration model reconciles previous discrepancies and demonstrates the importance of protein-interaction kinetics in regulating biological processes.


Assuntos
Proteínas de Ciclo Celular/metabolismo , Heterocromatina/metabolismo , Histona Metiltransferases/metabolismo , Histona-Lisina N-Metiltransferase/metabolismo , Histonas/metabolismo , Proteínas de Schizosaccharomyces pombe/metabolismo , Ubiquitinação/imunologia , Mutação
12.
Cell Rep ; 33(13): 108561, 2020 12 29.
Artigo em Inglês | MEDLINE | ID: mdl-33378674

RESUMO

One key aspect of epigenetic inheritance is that chromatin structures can be stably inherited through generations after the removal of the signals that establish such structures. In fission yeast, the RNA interference (RNAi) pathway is critical for the targeting of histone methyltransferase Clr4 to pericentric repeats to establish heterochromatin. However, pericentric heterochromatin cannot be properly inherited in the absence of RNAi, suggesting the existence of mechanisms that counteract chromatin structure inheritance. Here, we show that mutations of components of the INO80 chromatin-remodeling complex allow pericentric heterochromatin inheritance in RNAi mutants. The ability of INO80 to counter heterochromatin inheritance is attributed to one subunit, Iec5, which promotes histone turnover at heterochromatin but has little effects on nucleosome positioning at heterochromatin, gene expression, or the DNA damage response. These analyses demonstrate the importance of the INO80 chromatin-remodeling complex in controlling heterochromatin inheritance and maintaining the proper heterochromatin landscape of the genome.


Assuntos
Proteínas de Ciclo Celular/genética , Epigênese Genética , Heterocromatina/genética , Heterocromatina/metabolismo , Histona-Lisina N-Metiltransferase/genética , Interferência de RNA , Proteínas de Schizosaccharomyces pombe/genética , Proteínas de Schizosaccharomyces pombe/fisiologia , Schizosaccharomyces/fisiologia , Fatores de Transcrição/fisiologia , Montagem e Desmontagem da Cromatina , Replicação do DNA , Epigenômica , Histonas/metabolismo , Mutação
13.
Mol Plant ; 13(7): 1063-1077, 2020 07 06.
Artigo em Inglês | MEDLINE | ID: mdl-32422188

RESUMO

Plant cell growth involves a complex interplay among cell-wall expansion, biosynthesis, and, in specific tissues, secondary cell wall (SCW) deposition, yet the coordination of these processes remains elusive. Cotton fiber cells are developmentally synchronous, highly elongated, and contain nearly pure cellulose when mature. Here, we report that the transcription factor GhTCP4 plays an important role in balancing cotton fiber cell elongation and wall synthesis. During fiber development the expression of miR319 declines while GhTCP4 transcript levels increase, with high levels of the latter promoting SCW deposition. GhTCP4 interacts with a homeobox-containing factor, GhHOX3, and repressing its transcriptional activity. GhTCP4 and GhHOX3 function antagonistically to regulate cell elongation, thereby establishing temporal control of fiber cell transition to the SCW stage. We found that overexpression of GhTCP4A upregulated and accelerated activation of the SCW biosynthetic pathway in fiber cells, as revealed by transcriptome and promoter activity analyses, resulting in shorter fibers with varied lengths and thicker walls. In contrast, GhTCP4 downregulation led to slightly longer fibers and thinner cell walls. The GhHOX3-GhTCP4 complex may represent a general mechanism of cellular development in plants since both are conserved factors in many species, thus providing us a potential molecular tool for the design of fiber traits.


Assuntos
Parede Celular/metabolismo , Gossypium/metabolismo , MicroRNAs/metabolismo , Proteínas de Plantas/metabolismo , Fatores de Transcrição/metabolismo , Celulose/metabolismo , Fibra de Algodão , Regulação da Expressão Gênica de Plantas , Proteínas de Homeodomínio/metabolismo
14.
Physiol Plant ; 134(1): 174-82, 2008 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-18507789

RESUMO

Most of the plant homeodomain-containing proteins play important roles in organ patterning and development, and Arabidopsis GLABRA2 (GL2), a member of the class IV homeodomain-leucine zipper (HD-ZIP) proteins, is a trichome and non-root hair cell regulator. Here we report the analysis of two cotton homeodomain-containing proteins, GaHOX1 and GaHOX2, isolated from the diploid cotton Gossypium arboreum. Both GaHOX1 and GaHOX2 belong to the class IV HD-ZIP family. When expressed under the control of the GL2 promoter, GaHOX1 rescued trichome development of an Arabidopsis glabrous mutant of gl2-2 (SALK_130213), whereas GaHOX2 did not. On the other hand, expression of GaHOX1 with a Cauliflower mosaic virus (CaMV) 35S promoter in the wild-type Arabidopsis plants suppressed the trichome development just as the GL2 ectopic expression. Expression analysis by Northern, RT-PCR and in situ hybridization indicated that GaHOX1 is predominantly expressed in cotton fiber cells at early developmental stages, consistent with its putative role in regulating cotton fiber development, while GaHOX2 is expressed in both fiber and other ovular tissues, including outer and inner integuments. Our results suggest that GaHOX1 is a functional homolog of GL2 in plant trichome development.


Assuntos
Proteínas de Arabidopsis/metabolismo , Arabidopsis/metabolismo , Gossypium/metabolismo , Proteínas de Homeodomínio/metabolismo , Proteínas de Plantas/metabolismo , Arabidopsis/genética , Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/fisiologia , Regulação da Expressão Gênica de Plantas , Gossypium/genética , Proteínas de Homeodomínio/genética , Proteínas de Homeodomínio/fisiologia , Proteínas de Plantas/genética , Proteínas de Plantas/fisiologia , Plantas Geneticamente Modificadas/genética , Plantas Geneticamente Modificadas/metabolismo
15.
Sci Rep ; 7: 43906, 2017 03 03.
Artigo em Inglês | MEDLINE | ID: mdl-28256625

RESUMO

Histone H3 lysine 36 methylation (H3K36me) is critical for epigenetic regulation and mutations at or near H3K36 are associated with distinct types of cancers. H3K36M dominantly inhibits H3K36me on wild-type histones, whereas H3G34R/V selectively affects H3K36me on the same histone tail. Here we report the crystal structures of SETD2 SET domain in complex with an H3K36M peptide and SAM or SAH. There are large conformational changes in the substrate binding regions of the SET domain, and the K36M residue interacts with the catalytic pocket of SETD2. H3G34 is surrounded by a very narrow tunnel, which excludes larger amino acid side chains. H3P38 is in the trans configuration, and the cis configuration is incompatible with SETD2 binding. Finally, mutations of H3G34 or H3P38 alleviate the inhibitory effects of H3K36M on H3K36me, demonstrating that the stable interaction of H3K36M with SETD2 is critical for its inhibitory effects.


Assuntos
Histona-Lisina N-Metiltransferase/química , Histonas/química , Histonas/genética , Proteínas Mutantes/química , Proteínas Mutantes/genética , Mutação de Sentido Incorreto , Processamento de Proteína Pós-Traducional , Cristalografia por Raios X , Epigênese Genética , Histona-Lisina N-Metiltransferase/metabolismo , Histonas/metabolismo , Humanos , Metilação , Proteínas Mutantes/metabolismo , Neoplasias/patologia , Ligação Proteica , Conformação Proteica
16.
Elife ; 52016 09 20.
Artigo em Inglês | MEDLINE | ID: mdl-27648579

RESUMO

Histone lysine-to-methionine (K-to-M) mutations are associated with multiple cancers, and they function in a dominant fashion to block the methylation of corresponding lysines on wild type histones. However, their mechanisms of function are controversial. Here we show that in fission yeast, introducing the K9M mutation into one of the three histone H3 genes dominantly blocks H3K9 methylation on wild type H3 across the genome. In addition, H3K9M enhances the interaction of histone H3 tail with the H3K9 methyltransferase Clr4 in a SAM (S-adenosyl-methionine)-dependent manner, and Clr4 is trapped at nucleation sites to prevent its spreading and the formation of large heterochromatin domains. We further determined the crystal structure of an H3K9M peptide in complex with human H3K9 methyltransferase G9a and SAM, which reveales that the methionine side chain had enhanced van der Waals interactions with G9a. Therefore, our results provide a detailed mechanism by which H3K9M regulates H3K9 methylation.


Assuntos
Substituição de Aminoácidos , Proteínas de Ciclo Celular/metabolismo , Heterocromatina/metabolismo , Histonas/genética , Histonas/metabolismo , Metiltransferases/metabolismo , Proteínas de Schizosaccharomyces pombe/metabolismo , Schizosaccharomyces/genética , Schizosaccharomyces/metabolismo , Cristalografia por Raios X , Histona-Lisina N-Metiltransferase , Histonas/química , Humanos , Lisina/genética , Lisina/metabolismo , Metionina/genética , Metionina/metabolismo , Modelos Moleculares , Conformação Proteica
17.
Mol Plant ; 8(1): 98-110, 2015 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-25578275

RESUMO

Plant metabolites vary at different stages of their life cycle. Although it is well documented that environmental factors stimulate biosynthesis of secondary metabolites, the regulation by endogenous developmental cues remains poorly understood. The microRNA156 (miR156)-targeted squamosa promoter binding protein-like (SPL) factors function as a major age cue in regulating developmental phase transition and flowering. We show here that the miR156-targeted SPL transcription factor plays an important role in the spatiotemporal regulation of sesquiterpene biosynthesis. In Arabidopsis thaliana, the miR156-SPL module regulates the formation of (E)-ß-caryophyllene in the flowering stage through modulating expression of the sesquiterpene synthase gene TPS21. We demonstrated that SPL9 directly binds to TPS21 promoter and activates its expression. In the perennial fragrant herb Pogostemon cablin, the accumulation of patchouli oil, largely composed of sesquiterpenes dominated by (-)-patchoulol, is also age-regulated, and the SPL promotes biosynthesis of sesquiterpenes in elder plants by upregulating patchoulol synthase (PatPTS) gene expression. As miR156-SPLs are highly conserved in plants, our finding not only uncovers a molecular link between developmental timing and sesquiterpene production but also suggests a new strategy to engineer plants for accelerated growth with enhanced production of terpenoids.


Assuntos
Arabidopsis/metabolismo , MicroRNAs/metabolismo , Sesquiterpenos/metabolismo , Fatores de Transcrição/metabolismo , Proteínas de Arabidopsis/metabolismo , MicroRNAs/genética , Dados de Sequência Molecular , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Plantas Geneticamente Modificadas/genética , Plantas Geneticamente Modificadas/metabolismo , Regiões Promotoras Genéticas
18.
Sci Rep ; 5: 14139, 2015 Sep 30.
Artigo em Inglês | MEDLINE | ID: mdl-26420475

RESUMO

Of the two cultivated species of allopolyploid cotton, Gossypium barbadense produces extra-long fibers for the production of superior textiles. We sequenced its genome (AD)2 and performed a comparative analysis. We identified three bursts of retrotransposons from 20 million years ago (Mya) and a genome-wide uneven pseudogenization peak at 11-20 Mya, which likely contributed to genomic divergences. Among the 2,483 genes preferentially expressed in fiber, a cell elongation regulator, PRE1, is strikingly At biased and fiber specific, echoing the A-genome origin of spinnable fiber. The expansion of the PRE members implies a genetic factor that underlies fiber elongation. Mature cotton fiber consists of nearly pure cellulose. G. barbadense and G. hirsutum contain 29 and 30 cellulose synthase (CesA) genes, respectively; whereas most of these genes (>25) are expressed in fiber, genes for secondary cell wall biosynthesis exhibited a delayed and higher degree of up-regulation in G. barbadense compared with G. hirsutum, conferring an extended elongation stage and highly active secondary wall deposition during extra-long fiber development. The rapid diversification of sesquiterpene synthase genes in the gossypol pathway exemplifies the chemical diversity of lineage-specific secondary metabolites. The G. barbadense genome advances our understanding of allopolyploidy, which will help improve cotton fiber quality.


Assuntos
Evolução Biológica , Fibra de Algodão , Genoma de Planta , Genômica , Gossypium/genética , Gossypium/metabolismo , Metabolômica , Alquil e Aril Transferases/genética , Alquil e Aril Transferases/metabolismo , Cromossomos de Plantas , Análise por Conglomerados , Biologia Computacional/métodos , Perfilação da Expressão Gênica , Estudos de Associação Genética , Genômica/métodos , Metabolômica/métodos , Anotação de Sequência Molecular , Fenótipo , Filogenia , Poliploidia , Característica Quantitativa Herdável , Sesquiterpenos/metabolismo , Translocação Genética , Fitoalexinas
19.
Mol Plant ; 2014 Oct 29.
Artigo em Inglês | MEDLINE | ID: mdl-25355059

RESUMO

Plant metabolites vary at different stages of life cycle. Although it is well documented that environmental factors stimulate biosynthesis of secondary metabolites, the regulation by endogenous developmental cues remains poorly understood. The microRNA156 (miR156)-tageted SQUAMOSA PROMOTER BINDING PROTEIN-LIKE (SPL) factors function as a major age cue in regulating developmental phase transition and flowering. We show here that the miR156-targeted SPL transcription factor plays an important role in the spatiotemporal regulation of sesquiterpene biosynthesis. In Arabidopsis thaliana, the miR156-SPL module regulates the formation of (E)-ß-caryophyllene in flowering stage through modulating expression of the sesquiterpene synthase gene TPS21. We demonstrated that SPL9 directly binds to TPS21 promoter and activates its expression. In the perennial fragrant herb Pogostemon cablin, the accumulation of "patchouli oil", largely composed of sesquiterpenes dominated by (-)-patchoulol, is also age-regulated, and the SPL promotes biosynthesis of sesquiterpenes in elder plants by up-regulating patchoulol synthase (PatPTS) gene expression. As miR156-SPLs are highly conserved in plants, our finding not only uncovers a molecular link between developmental timing and sesquiterpene production, but also suggests a new strategy to engineer plant for accelerated growth with enhanced production of terpenoids.

20.
Nat Commun ; 5: 5519, 2014 Nov 21.
Artigo em Inglês | MEDLINE | ID: mdl-25413731

RESUMO

Cotton fibres are unusually long, single-celled epidermal seed trichomes and a model for plant cell growth, but little is known about the regulation of fibre cell elongation. Here we report that a homeodomain-leucine zipper (HD-ZIP) transcription factor, GhHOX3, controls cotton fibre elongation. GhHOX3 genes are localized to the 12th homoeologous chromosome set of allotetraploid cotton cultivars, associated with quantitative trait loci (QTLs) for fibre length. Silencing of GhHOX3 greatly reduces (>80%) fibre length, whereas its overexpression leads to longer fibre. Combined transcriptomic and biochemical analyses identify target genes of GhHOX3 that also contain the L1-box cis-element, including two cell wall loosening protein genes GhRDL1 and GhEXPA1. GhHOX3 interacts with GhHD1, another homeodomain protein, resulting in enhanced transcriptional activity, and with cotton DELLA, GhSLR1, repressor of the growth hormone gibberellin (GA). GhSLR1 interferes with the GhHOX3-GhHD1 interaction and represses target gene transcription. Our results uncover a novel mechanism whereby a homeodomain protein transduces GA signal to promote fibre cell elongation.


Assuntos
Gossypium/crescimento & desenvolvimento , Proteínas de Homeodomínio/metabolismo , Zíper de Leucina/fisiologia , Proteínas de Plantas/metabolismo , Tricomas/crescimento & desenvolvimento , Fibra de Algodão , Perfilação da Expressão Gênica , Regulação da Expressão Gênica no Desenvolvimento , Regulação da Expressão Gênica de Plantas , Giberelinas/metabolismo , Histona Desacetilases/metabolismo , Dados de Sequência Molecular , Reguladores de Crescimento de Plantas/metabolismo , Locos de Características Quantitativas
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