Article

Genome-wide location analysis of the stress-activated MAP kinase Hog1 in yeast.

Instituto de Biología Molecular y Celular de Plantas (IBMCP), Universidad Politécnica de Valencia, 46022 Valencia, Spain.
Methods (Impact Factor: 3.22). 12/2006; 40(3):272-8. DOI: 10.1016/j.ymeth.2006.06.007
Source: PubMed

ABSTRACT MAP kinase signal transduction pathways play a critical role in eukaryotic cells to unleash complex transcriptional programs to properly adapt to changing environments. The MAP kinase Hog1 upon activation is physically recruited to the chromatin of osmostress responsive genes. This allowed us to use in vivo chromatin immunoprecipitation in combination with microarrays (ChIP-Chip) to identify the transcriptional targets of Hog1 at the genomic scale. The ChIP-Chip method described here revealed that the stress-activated MAP kinase gets recruited to most of the osmoinducible genes. Interestingly Hog1 associates with both the 5' upstream and the 3' downstream sequences of stress genes. We confirmed by targeted ChIP at several stress genes that the MAP kinase crosslinks all over the transcribed regions in all cases tested. Taken together the genome-wide location analysis reported here is a powerful approach to determine the genomic binding patterns of an activated MAP kinase and will be of great interest to analyze other SAPKs under different environmental conditions.

0 Bookmarks
 · 
81 Views
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Transcription during Sphase needs to be spatially and temporally regulated to prevent collisions between the transcription and replication machineries. Cells have evolved a number of mechanisms to make compatible both processes under normal growth conditions. When conflict management fails, the head-on encounter between RNA and DNA polymerases results in genomic instability unless conflict resolution mechanisms are activated. Nevertheless, there are specific situations in which cells need to dramatically change their transcriptional landscape to adapt to environmental challenges. Signal transduction pathways, such as stress-activated protein kinases (SAPKs), serve to regulate gene expression in response to environmental insults. Prototypical members of SAPKs are the yeast Hog1 and mammalian p38. In response to stress, p38/Hog1 SAPKs control transcription and also regulate cell cycle progression. When yeast cells are stressed during S phase, Hog1 promotes gene induction and remarkably, also delays replication by directly affecting early origin firing and fork progression. Therefore, by delaying replication, Hog1 plays a key role in preventing conflicts between RNA and DNA polymerases. In this review, we focus on the genomic determinants and mechanisms that make compatible transcription with replication during S phase to prevent genomic instability, especially in response to environmental changes.
    Journal of Molecular Biology 09/2013; · 3.91 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Eukaryotic cells have developed sophisticated systems to constantly monitor changes in the extracellular environment and to orchestrate a proper cellular response. To maximize survival, cells delay cell-cycle progression in response to environmental changes. In response to extracellular insults, stress-activated protein kinases (SAPKs) modulate cell-cycle progression and gene expression. In yeast, osmostress induces activation of the p38-related SAPK Hog1, which plays a key role in reprogramming gene expression upon osmostress. Genomic analysis has revealed the existence of a large number of long non-coding RNAs (lncRNAs) with different functions in a variety of organisms, including yeast. Upon osmostress, hundreds of lncRNAs are induced by the SAPK p38/Hog1. One gene that expresses Hog1-dependent lncRNA in an antisense orientation is the CDC28 gene, which encodes CDK1 kinase that controls the cell cycle in yeast. Cdc28 lncRNA mediates the induction of CDC28 expression and this increase in the level of Cdc28 results in more efficient re-entry of the cells into the cell cycle after stress. Thus, the control of lncRNA expression as a new mechanism for the regulation of cell-cycle progression opens new avenues to understand how stress adaptation can be accomplished in response to changing environments.
    Current Genetics 09/2014; · 1.71 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Epithelial to mesenchymal transition (EMT) is activated during cancer invasion and metastasis, enriches for cancer stem cells (CSCs), and contributes to therapeutic resistance and disease recurrence. Signal transduction kinases play a pivotal role as chromatin-anchored proteins in eukaryotes. Here we report for the first time that protein kinase C-theta (PKC-θ) promotes EMT by acting as a critical chromatin-anchored switch for inducible genes via TGF-β and the key inflammatory regulatory protein, NF-κB. Chromatinized PKC-θ exists as an active transcription complex and is required to establish a permissive chromatin state at signature EMT genes. Genome-wide analysis identifies a unique cohort of inducible PKC-θ-sensitive genes that are directly tethered to PKC-θ in the mesenchymal state. Collectively, we show that crosstalk between signaling kinases and chromatin is critical for eliciting inducible transcriptional programs that drive mesenchymal differentiation and CSC formation, providing novel mechanisms to target using epigenetic therapy in breast cancer.
    Molecular and Cellular Biology 06/2014; · 5.04 Impact Factor

Full-text (2 Sources)

Download
50 Downloads
Available from
Jun 2, 2014