Subnuclear localization and mitotic phosphorylation of HIRA, the human homologue of Saccharomyces cerevisiae transcriptional regulators Hir1p/Hir2p

Lucia, Filomena De; Lorain, Stéphanie; Scamps, Christine; Galisson, Frédéric; Machold, Jan; Lipinski, Marc

doi:10.1042/0264-6021:3580447

Cited by 16 publications

(20 citation statements)

References 48 publications

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“…More specifically, these phosphorylation events may negatively regulate the ability of Gro/TLEs to interact with components of chromatin and/or the nuclear matrix, thereby playing a negative regulatory role in Gro/TLE functions. Such a model is consistent with the observation that mitotic phosphorylation events decrease the interaction with chromatin of another mammalian protein, termed HIRA, that is structurally related to Gro/TLEs and is also involved in transcriptional repression (42).…”

Section: Discussionsupporting

confidence: 71%

“…After this time, mitotically enriched cells that were loosely attached or floating were collected by gentle pipetting, whereas adherent cells were not collected. This protocol was shown to yield greater than 80% of cells with a DNA content corresponding to the G 2 /M phase, with most of these cells being in mitosis (42). Cultures enriched for cells arrested at the G 1 /S transition were obtained by treatment with 10 mM hydroxyurea (41), followed by removal of floating or loosely attached cells and recovery of the strongly adherent cells.…”

Section: Methodsmentioning

confidence: 99%

“…lanes [3][4][5][6]. The chosen concentrations of these pharmacological inhibitors were shown to maintain viability of the cells and not induce irreversible arrest in G 2 phase (42,44). Importantly, both of these inhibitors also increased Gro/TLE mobility in the absence of okadaic acid (Fig.…”

Section: Okadaic Acid-induced Phosphorylation Of Gro/tle Proteinsmentioning

confidence: 99%

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A Role for Cell Cycle-regulated Phosphorylation in Groucho-mediated Transcriptional Repression

Nuthall¹,

Joachim

Palaparti

et al. 2002

Journal of Biological Chemistry

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Transcriptional corepressors of the Groucho/transducin-like Enhancer of split (Gro/TLE) family are involved in a variety of cell differentiation mechanisms in both invertebrates and vertebrates. They become recruited to specific promoter regions by forming complexes with a number of different DNA-binding proteins thereby contributing to the regulation of multiple genes. To understand how the functions of Gro/TLE proteins are regulated, it was asked whether their ability to mediate transcriptional repression might be controlled by cell cycle-dependent phosphorylation events. It is shown here that activation of p34 cdc2 kinase (cdc2) with okadaic acid is correlated with hyperphosphorylation of Gro/TLEs. Moreover, pharmacological inhibition of cdc2 activity results in Gro/TLE dephosphorylation. In agreement with these findings, a purified cdc2-cyclin B complex can directly phosphorylate Gro/TLEs in vitro. Two separate Gro/TLE domains, the CcN and SP regions, contain sequences that are phosphorylated by cdc2. Deletion of these sequences is correlated with loss of Gro/ TLE phosphorylation by cdc2 in vitro and okadaic acidinduced Gro/TLE hyperphosphorylation in vivo. In addition, Gro/TLEs are phosphorylated during the G 2 /M phase of the cell cycle, and this is correlated with a decreased nuclear interaction. Finally, the transcription repression ability of Gro/TLEs is enhanced by pharmacological inhibition of cdc2. Taken together, these results demonstrate that Gro/TLE proteins are phosphorylated as a function of the cell cycle and implicate phosphorylation events occurring during mitosis in the negative regulation of Gro/TLE activity.In both invertebrates and vertebrates, transcriptional corepressor proteins of the Groucho/transducin-like Enhancer of split (Gro/TLE) 1 family play crucial roles in the regulation of a variety of cell differentiation mechanisms. In particular, Drosophila Gro is required for sex determination, segmentation, and neural development (1). Vertebrate Gro/TLE proteins contribute to the regulation of neuronal development (2), patterning of the neural tube (3, 4), skeletogenesis (5, 6), hematopoiesis (7-9), and myogenesis (10, 11). Gro/TLE proteins have no intrinsic DNA binding activity but can be targeted to specific gene regulatory regions due to their ability to interact with a number of different DNA-binding transcription factors. Examples of these include basic helixloop-helix proteins of the Hes family (12-17), Runt homology domain proteins of the Runt/RUNX family (7,18,19), homeodomain factors containing engrailed homology region 1 motifs (3, 20 -24), winged-helix domain transcription factors (23, 25), and high mobility group box proteins (7, 9). By virtue of these multiple interactions, the general transcription repression activity of Gro/TLE proteins can be recruited in context-dependent manners to specific target genes.Transcriptional repression by Gro/TLE family members is thought to be mediated by at least two mechanisms. Oligomeric Gro/TLEs can interact with both histones (26, 27) ...

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Section: Discussionsupporting

confidence: 71%

Section: Methodsmentioning

confidence: 99%

See 1 more Smart Citation

A Role for Cell Cycle-regulated Phosphorylation in Groucho-mediated Transcriptional Repression

Nuthall¹,

Joachim

Palaparti

et al. 2002

Journal of Biological Chemistry

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“…Moreover, we showed that ectopic expression of HIRA inhibited DNA synthesis and arrested cells in S phase of the cell cycle (21). De Lucia and coworkers showed that HIRA is phosphorylated during mitosis and that phosphorylation is accompanied by release from nuclear chromatin (11). HIRA has been shown to interact with several proteins implicated in control of transcription and nuclear structure, including Pax3 and histones (36,40).…”

mentioning

confidence: 99%

Coupling of DNA Synthesis and Histone Synthesis in S Phase Independent of Cyclin/cdk2 Activity

Nelson

Hall

et al. 2002

Molecular and Cellular Biology

169

131

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DNA and histone synthesis are both triggered at the beginning of S phase by cyclin/cdk2 activity. Previous studies showed that inhibition of DNA synthesis with hydroxyurea or cytosine arabinoside (AraC) triggers a concerted repression of histone synthesis, indicating that sustained histone synthesis depends on continued DNA synthesis. Here we show that ectopic expression of HIRA, the likely human ortholog of two cell cycleregulated repressors of histone gene transcription in yeast (Hir1p and Hir2p), represses transcription of histones and that this, in turn, triggers a concerted block of DNA synthesis. Thus, in mammalian cells sustained DNA synthesis and histone synthesis are mutually dependent on each other during S phase. Although cyclin/cdk2 activity drives activation of both DNA and histone synthesis at the G 1 /S transition of cycling cells, concerted repression of DNA or histone synthesis in response to inhibition of either one of these is not accompanied by prolonged inhibition of cyclin A/cdk2 or E/cdk2 activity. Therefore, during S phase coupling of DNA and histone synthesis occurs, at least in part, through a mechanism that is independent of cyclin/cdk2 activity. Coupling of DNA and histone synthesis in S phase presumably contributes to the prompt and orderly assembly of newly replicated DNA into chromatin.Progression through the cell cycle is driven by the sequential and periodic activation of cyclin/cdk complexes (23, 27). For example, entry into and progression through S phase is promoted by activation of cyclin E/cdk2 and cyclin A/cdk2, whereas entry into mitosis is triggered by activation of cyclin B/cdc2. Numerous lines of evidence demonstrate that cyclin/ cdk2 activity plays a key role in initiation of S-phase events. Elevation of cyclin/cdk2 activity in G 1 phase causes premature entry into S phase (9,56,57,72), and inhibition of cyclin/cdk2 activity inhibits entry into and progression through S phase (20,52,67,76). Initiation of S phase depends on activation of a number of biosynthetic processes, including DNA synthesis, histone synthesis, and chromatin assembly (58).According to current models distinct S-phase processes, such as DNA synthesis and histone synthesis, are independently activated by cyclin/cdk2 at the start of S phase (17, 30). For example, activation of DNA synthesis depends on phosphorylation of Cdc6 and Cdc45. Increased histone synthesis in S phase is due to regulation at transcriptional and posttranscriptional levels. Histone gene transcription increases threeto fivefold as cells enter S phase, and this depends on phosphorylation of NPAT by cyclin E/cdk2 (30,39,42,50,74). However, posttranscriptional regulation accounts for the majority of the 35-to 50-fold increase in histone synthesis during S phase (42,50). The processing of the immature intronless pre-mRNA to the mature mRNA requires a cleavage within the 3Ј untranslated region (UTR); this occurs more efficiently in S phase (15,19,24,37,65), and the mRNA is also more stable at this time (10,24,25,62). The processing of th...

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“…The role of Hira in higher eukaryotes is not known, but the protein is localized to the nucleus where a proportion is associated with the nuclear matrix (15). Hira is a target for cdk2/ cyclin E phosphorylation, and ectopic expression of Hira can block cells in the S phase of the cell cycle (22).…”

mentioning

confidence: 99%

Targeted Mutagenesis of the Hira Gene Results in Gastrulation Defects and Patterning Abnormalities of Mesoendodermal Derivatives Prior to Early Embryonic Lethality

Roberts

Sutherland

Farmer

et al. 2002

Molecular and Cellular Biology

133

113

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The Hira gene encodes a nuclear WD40 domain protein homologous to the yeast transcriptional corepressors Hir1p and Hir2p. Using targeted mutagenesis we demonstrate that Hira is essential for murine embryogenesis. Analysis of inbred 129Sv embryos carrying the null mutation revealed an initial requirement during gastrulation, with many mutant embryos having a distorted primitive streak. Mutant embryos recovered at later stages have a range of malformations with axial and paraxial mesendoderm being particularly affected, a finding consistent with the disruption of gastrulation seen earlier in development. This phenotype could be partially rescued by a CD1 genetic background, although the homozygous mutation was always lethal by embryonic day 11, with death probably resulting from abnormal placentation and failure of cardiac morphogenesis.

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Subnuclear localization and mitotic phosphorylation of HIRA, the human homologue of Saccharomyces cerevisiae transcriptional regulators Hir1p/Hir2p

Cited by 16 publications

References 48 publications

A Role for Cell Cycle-regulated Phosphorylation in Groucho-mediated Transcriptional Repression

A Role for Cell Cycle-regulated Phosphorylation in Groucho-mediated Transcriptional Repression

Coupling of DNA Synthesis and Histone Synthesis in S Phase Independent of Cyclin/cdk2 Activity

Targeted Mutagenesis of the Hira Gene Results in Gastrulation Defects and Patterning Abnormalities of Mesoendodermal Derivatives Prior to Early Embryonic Lethality

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