Vogler C.,Max Planck Institute of Immunobiology
PLoS genetics | Year: 2010
The tails of histone proteins are central players for all chromatin-mediated processes. Whereas the N-terminal histone tails have been studied extensively, little is known about the function of the H2A C-terminus. Here, we show that the H2A C-terminal tail plays a pivotal role in regulating chromatin structure and dynamics. We find that cells expressing C-terminally truncated H2A show increased stress sensitivity. Moreover, both the complete and the partial deletion of the tail result in increased histone exchange kinetics and nucleosome mobility in vivo and in vitro. Importantly, our experiments reveal that the H2A C-terminus is required for efficient nucleosome translocation by ISWI-type chromatin remodelers and acts as a novel recognition module for linker histone H1. Thus, we suggest that the H2A C-terminal tail has a bipartite function: stabilisation of the nucleosomal core particle, as well as mediation of the protein interactions that control chromatin dynamics and conformation.
Sen R.,U.S. National Institute on Aging |
Grosschedl R.,Max Planck Institute of Immunobiology
Genes and Development | Year: 2010
Transcriptional enhancers are key determinants of developmentally regulated gene expression. Models of enhancer function must distinguish between analog or digital control of transcription, as well as their requirement to initiate or maintain transcriptional activity of a gene. In light of a recent study by Chong and colleagues (pp. 659-669) providing evidence of a transient requirement of an enhancer associated with the CD4 gene, we discuss possible mechanisms by which transcriptional memory can be propagated in the absence of enhancers.
Feng W.,German Cancer Research Center |
Yonezawa M.,Research Institute of Molecular Pathology |
Yonezawa M.,Max Planck Institute of Immunobiology |
Ye J.,German Cancer Research Center |
And 3 more authors.
Nature Structural and Molecular Biology | Year: 2010
Histone lysine methylation is dynamically regulated by lysine methyltransferases and lysine demethylases. Here we show that PHD finger protein 8 (PHF8), a protein containing a PHD finger and a Jumonji C (JmjC) domain, is associated with hypomethylated rRNA genes (rDNA). PHF8 interacts with the RNA polymerase I transcription machinery and with WD repeat-containing protein 5 (WDR5)-containing H3K4 methyltransferase complexes. PHF8 exerts a positive effect on rDNA transcription, with transcriptional activation requiring both the JmjC domain and the PHD finger. PHF8 demethylates H3K9me1/2, and its catalytic activity is stimulated by adjacent H3K4me3. A point mutation within the JmjC domain that is linked to mental retardation with cleft lip and palate (XLMR-CL/P) abolishes demethylase activity and transcriptional activation. Though further work is needed to unravel the contribution of PHF8 activity to mental retardation and cleft lip/palate, our results reveal a functional interplay between H3K4 methylation and H3K9me1/2 demethylation, linking dynamic histone methylation to rDNA transcription and neural disease. © 2010 Nature America, Inc. All rights reserved.
Stemmler M.P.,Max Planck Institute of Immunobiology |
Bedzhov I.,Max Planck Institute of Immunobiology
Developmental Dynamics | Year: 2010
The specific roles of classical cadherins at key morphogenetic events during development are still not fully understood. As part of a project to study cadherin function during early mammalian development, we generated mice carrying an HA-epitope tagged Cdh1 (E-cadherin) cDNA knocked into the Cdh1 locus, similar to the previously described mouse mutants in which we forced Cdh2 (N-cadherin) expression in the Cdh1 expression domain. As expected and in contrast to Cdh1Cdh2/Cdh2 and Cdh1-/-, our Cdh1 HA/HA mutant embryos form proper trophectoderm, implant and undergo both gastrulation and neurulation. However, Cdh1HA/HA mice display an unexpected phenotype at embryonic day 10.5. Cdh1HA/HA embryos are smaller, paler and suffer from an insufficient nutrient supply. We detected a reduced expression of Cdh1HA specifically in the extraembryonic ectoderm and in the labyrinth layer, whereas expression in the embryo proper was normal. With this approach, we show for the first time that Cdh1 is essential for the correct formation of the placenta. Placentas without Cdh1 expression are impaired and incapable of establishing a proper connection between the embryonic and the maternal blood vessels for efficient nutrient and oxygen transport. © 2010 Wiley-Liss, Inc.
Tropberger P.,Max Planck Institute of Immunobiology |
Schneider R.,Max Planck Institute of Immunobiology
Epigenetics | Year: 2010
Post-translational modifications (PTM) of histones are key regulators of chromatin function. New mass spectrometrical technologies have revealed that PTMs are not restricted to the histone tails, but can also be found in the globular domains, especially at the DNA-binding surface of the nucleosomes. Recent work on this new group of epigenetic marks showed that these modifications have not only the potential to alter the physical properties of the nucleosome, but may act as signals that regulate the recruitment of effector proteins to chromatin as well. © 2010 Landes Bioscience.