MED25 is distinct from TRAP220/MED1 in cooperating with CBP for retinoid receptor activation

Lee, Hye Kyung; Park, Ui-Hyun; Kim, Eun-Joo; Um, Soo‐Jong

doi:10.1038/sj.emboj.7601797

Cited by 75 publications

(91 citation statements)

References 44 publications

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“…Thus, in term of their interaction with MED25, the JA-Ile coreceptor complex (SCF COI1 -JAZs), together with the master transcription factor MYC2, resembles the NR system of metazoans (26,28,29,47). Third, we show here that the plant MED25 cooperates with HAC1, an Arabidopsis ortholog of the well-studied animal histone acetyltransferase CBP, for JA-Iletriggered activation of MYC2; in a similar manner, the animal MED25 also cooperates with CBP for RAR activation (48). Thus, the plant MED25 and its animal counterpart cooperate with similar epigenetic regulators in distinct signaling pathways.…”

Section: Discussionmentioning

confidence: 55%

Mediator subunit MED25 links the jasmonate receptor to transcriptionally active chromatin

Lin

Zhai

et al. 2017

Proc. Natl. Acad. Sci. U.S.A.

146

180

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Jasmonoyl-isoleucine (JA-Ile), the active form of the plant hormone jasmonate (JA), is sensed by the F-box protein CORONATINE INSENSITIVE 1 (COI1), a component of a functional Skp-Cullin-F-box E3 ubiquitin ligase complex. Sensing of JA-Ile by COI1 rapidly triggers genome-wide transcriptional changes that are largely regulated by the basic helix-loop-helix transcription factor MYC2. However, it remains unclear how the JA-Ile receptor protein COI1 relays hormone-specific regulatory signals to the RNA polymerase II general transcriptional machinery. Here, we report that the plant transcriptional coactivator complex Mediator directly links COI1 to the promoters of MYC2 target genes. MED25, a subunit of the Mediator complex, brings COI1 to MYC2 target promoters and facilitates COI1-dependent degradation of jasmonate-ZIM domain (JAZ) transcriptional repressors. MED25 and COI1 influence each other's enrichment on MYC2 target promoters. Furthermore, MED25 physically and functionally interacts with HISTONE ACETYLTRANSFERASE1 (HAC1), which plays an important role in JA signaling by selectively regulating histone (H) 3 lysine (K) 9 (H3K9) acetylation of MYC2 target promoters. Moreover, the enrichment and function of HAC1 on MYC2 target promoters depend on COI1 and MED25. Therefore, the MED25 interface of Mediator links COI1 with HAC1-dependent H3K9 acetylation to activate MYC2-regulated transcription of JAresponsive genes. This study exemplifies how a single Mediator subunit integrates the actions of both genetic and epigenetic regulators into a concerted transcriptional program.is an oxylipin-derived plant hormone that regulates diverse aspects of plant immunity and development (1, 2). Decades of studies in the model plant Arabidopsis thaliana have revealed a core JA signaling module consisting of the F-box protein CORONATINE INSENSITIVE 1 (COI1) (3), a group of jasmonate-ZIM domain (JAZ) proteins (4-6), and the basic helixloop-helix transcription factor MYC2 (7, 8). COI1 forms a functional Skp-Cullin-F-box (SCF) E3 ubiquitin ligase SCF COI1 along with Cullin1 and Skp1-like1 (ASK1) (9, 10), MYC2 acts as a master transcription factor that differentially regulates diverse aspects of JA responses (11-13), and the JAZ proteins are substrates of SCF COI1 and serve as transcriptional repressors of MYC2 (4, 5, 14). The identification of jasmonoyl-isoleucine (JA-Ile) as the receptor-active form of the hormone, along with the discovery that sensing of JA-Ile involves formation of the SCF COI1 -JAZs coreceptor complex (4, 15-17), represented a breakthrough in our mechanistic understanding of JA signaling. In the absence of the hormone, JAZ repressors interact with and repress the activity of MYC2. In response to internal or external cues that trigger JAIle synthesis, elevated JA-Ile levels promote SCF COI1 -dependent degradation of JAZ repressors, and thereby activate (de-repress) the MYC2-directed transcriptional program. These discoveries imply that sensing of the active hormone is tightly linked to transcription of JA-responsive...

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Section: Discussionmentioning

confidence: 55%

Mediator subunit MED25 links the jasmonate receptor to transcriptionally active chromatin

Lin

Zhai

et al. 2017

Proc. Natl. Acad. Sci. U.S.A.

146

180

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“…For example, members of the nuclear receptor superfamily recruit Mediator via direct interactions with discrete LXXLL motifs within its MED1 subunit (52)(53)(54)(55)(56), while another class of activators, including adenovirus E1A, Esx, Elk-1, and C/EBP␤ instead target Mediator through its MED23 subunit (57)(58)(59)(60). Furthermore, MEDs 12,14,15,16,17, and 25 have each been implicated as direct physical and functional targets within Mediator of various gene-specific transcriptional activators (38,45,(61)(62)(63)(64)(65)(66)(67)(68)(69)(70)(71). Our discovery that Mediator, through its MED19/MED26 interface, is recruited by RE1-bound REST to silence neuronal genes thus provides a repressive corollary to the well-characterized mechanism of activator-dependent Mediator recruitment.…”

Section: Discussionmentioning

confidence: 99%

MED19 and MED26 Are Synergistic Functional Targets of the RE1 Silencing Transcription Factor in Epigenetic Silencing of Neuronal Gene Expression

Ding

Tomomori-Sato

Sato

et al. 2009

Journal of Biological Chemistry

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A key hub for the orchestration of epigenetic modifications necessary to restrict neuronal gene expression to the nervous system is the RE1 silencing transcription factor (REST; also known as neuron restrictive silencer factor, NRSF). REST suppresses the nonspecific and premature expression of neuronal genes in non-neuronal and neural progenitor cells, respectively, via recruitment of enzymatically diverse corepressors, including G9a histone methyltransferase (HMTase) that catalyzes di-methylation of histone 3-lysine 9 (H3K9me2). Recently, we identified the RNA polymerase II transcriptional Mediator to be an essential link between RE1-bound REST and G9a in epigenetic suppression of neuronal genes in non-neuronal cells. However, the means by which REST recruits Mediator to facilitate G9a-dependent extra-neuronal gene silencing remains to be elucidated. Here, we identify the MED19 and MED26 subunits in Mediator as direct physical and synergistic functional targets of REST. We show that although REST independently binds to both MED19 and MED26 in isolation, combined depletion of both subunits is required to disrupt the association of REST with Mediator. Furthermore, combined, but not individual, depletion of MED19/MED26 impairs REST-directed recruitment to RE1 elements of Mediator and G9a, leading to a reversal of G9a-dependent H3K9me2 and de-repression of REST-target gene expression. Together, these findings identify MED19/ MED26 as a probable composite REST interface in Mediator and further clarify the mechanistic basis by which Mediator facilitates REST-imposed epigenetic restrictions on neuronal gene expression.

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“…This is not surprising, since PFT1 is known to exert its effect on flowering only in response to a suboptimal light environment (Cerdán and Chory, 2003), specific conditions not analyzed in this study. Moreover, the role of PFT1 in chromatin remodeling via histone acetylases like human Med25 (Lee et al, 2007) cannot be underestimated.…”

Section: Expression Profile Of the Kinase Module And Other Associatedmentioning

confidence: 99%

The Mediator Complex in Plants: Structure, Phylogeny, and Expression Profiling of Representative Genes in a Dicot (Arabidopsis) and a Monocot (Rice) during Reproduction and Abiotic Stress

et al. 2011

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The Mediator (Med) complex relays regulatory information from DNA-bound transcription factors to the RNA polymerase II in eukaryotes. This macromolecular unit is composed of three core subcomplexes in addition to a separable kinase module. In this study, conservation of Meds has been investigated in 16 plant species representing seven diverse groups across the plant kingdom. Using Hidden Markov Model-based conserved motif searches, we have identified all the known yeast/metazoan Med components in one or more plant groups, including the Med26 subunits, which have not been reported so far for any plant species. We also detected orthologs for the Arabidopsis (Arabidopsis thaliana) Med32, -33, -34, -35, -36, and -37 in all the plant groups, and in silico analysis identified the Med32 and Med33 subunits as apparent orthologs of yeast/metazoan Med2/ 29 and Med5/24, respectively. Consequently, the plant Med complex appears to be composed of one or more members of 34 subunits, as opposed to 25 and 30 members in yeast and metazoans, respectively. Despite low similarity in primary Med sequences between the plants and their fungal/metazoan partners, secondary structure modeling of these proteins revealed a remarkable similarity between them, supporting the conservation of Med organization across kingdoms. Phylogenetic analysis between plant, human, and yeast revealed single clade relatedness for 29 Med genes families in plants, plant Meds being closer to human than to yeast counterparts. Expression profiling of rice (Oryza sativa) and Arabidopsis Med genes reveals that Meds not only act as a basal regulator of gene expression but may also have specific roles in plant development and under abiotic stress conditions.

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MED25 is distinct from TRAP220/MED1 in cooperating with CBP for retinoid receptor activation

Cited by 75 publications

References 44 publications

Mediator subunit MED25 links the jasmonate receptor to transcriptionally active chromatin

Mediator subunit MED25 links the jasmonate receptor to transcriptionally active chromatin

MED19 and MED26 Are Synergistic Functional Targets of the RE1 Silencing Transcription Factor in Epigenetic Silencing of Neuronal Gene Expression

The Mediator Complex in Plants: Structure, Phylogeny, and Expression Profiling of Representative Genes in a Dicot (Arabidopsis) and a Monocot (Rice) during Reproduction and Abiotic Stress

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