Publications related to Heterochromatin

Inheritance of H3K9 methylation regulates genome architecture in Drosophila early embryos

Constitutive heterochromatin is essential for transcriptional silencing and genome integrity. The establishment of constitutive heterochromatin in early embryos and its role in early fruitfly development are unknown. Lysine 9 trimethylation of histone H3 ( ...

Springernature2024

A Cluster of Evolutionarily Recent KRAB Zinc Finger Proteins Protects Cancer Cells from Replicative Stress–Induced Inflammation

Didier Trono, Priscilla Turelli, Sandra Eloise Kjeldsen, Evaristo Jose Planet Letschert, Filipe Amândio Brandão Sanches Vong Martins, Florian Huber, Cyril David Son-Tuyên Pulver, Olga Marie Louise Rosspopoff, Romain Forey, Joana Carlevaro Fita

Heterochromatin loss and genetic instability enhance cancer progression by favoring clonal diversity, yet uncontrolled replicative stress leads to mitotic catastrophe and inflammatory responses that promote immune rejection. KRAB domain-containing zinc fin ...

2024

Regulation and impact of TERRA R-loops at human telomeres

Rita Valador Fernandes

Telomeres are the nucleoprotein structures found at the ends of linear chromosomes. They ensure that the termini of chromosomes are not inappropriately recognized as sites of DNA damage, and are therefore crucial for genome stability. In spite of the heter ...

EPFL2023

CENP-A and CENP-B collaborate to create an open centromeric chromatin state

Beat Fierz, Wei Cai, Harsh Nagpal

Centromeres are epigenetically defined via the presence of the histone H3 variant CENP-A. Contacting CENP-A nucleosomes, the constitutive centromere associated network (CCAN) and the kinetochore assemble, connecting the centromere to spindle microtubules d ...

Nature Portfolio2023

Deciphering the molecular events leading to the global restoration of the chromatin landscape during mitotic exit

Silja Michelle Placzek

Two fundamental properties of embryonic stem cells (ESCs) are their ability to self-renew and differentiate into all somatic cell types. Maintenance of their identity faces major challenges when transitioning through mitosis, as most DNA-binding proteins a ...

EPFL2023

Telomere protection against oxidative stress

Thu Trang Nguyen

Telomeres are nucleoprotein structures at the ends of linear chromosomes, being essential for the maintenance of genomic integrity. Telomeres have a unique structure which distinguishes chromosome termini from DNA damage sites. Shelterin complexes are the ...

EPFL2023

Multivalent Peptide Ligands To Probe the Chromocenter Microenvironment in Living Cells

Beat Fierz, Pablo Rivera Fuentes, Nora Guidotti, Maxime Nicolas Mivelaz, Adam Miklos Eördögh

Chromatin is spatially organized into functional states that are defined by both the presence of specific histone post-translational modifications (PTMs) and a defined set of chromatin-associated “reader” proteins. Different models for the underlying mecha ...

2022

PR-DUB preserves Polycomb repression by preventing excessive accumulation of H2Aub1, an antagonist of chromatin compaction

Beat Fierz, Iuliia Boichenko

The Polycomb repressive complexes PRC1, PRC2, and PR-DUB repress target genes by modifying their chromatin. In Drosophila, PRC1 compacts chromatin and monoubiquitinates histone H2A at lysine 118 (H2Aub1), whereas PR-DUB is a major H2Aub1 deubiquitinase, bu ...

2022

Histone acetylation dynamics modulates chromatin conformation and allele-specific interactions at oncogenic loci

Elisa Oricchio, Natalya Katanayeva, Daniele Tavernari, Stephanie Jocelyne Sungalee, Ruxandra-Andreea Lambuta, Giovanni Ciriello

In cancer cells, enhancer hijacking mediated by chromosomal alterations and/or increased deposition of acetylated histone H3 lysine 27 (H3K27ac) can support oncogene expression. However, how the chromatin conformation of enhancer-promoter interactions is a ...

2021

Tracking the cargo of extracellular symbionts into host tissues with correlated electron microscopy and nanoscale secondary ion mass spectrometry imaging

Anders Meibom, Stéphane Laurent Escrig, Stéphanie Kéren Cohen

Extracellular bacterial symbionts communicate biochemically with their hosts to establish niches that foster the partnership. Using quantitative ion microprobe isotopic imaging (nanoscale secondary ion mass spectrometry [NanoSIMS]), we surveyed localizatio ...

WILEY2020

RAD51-dependent recruitment of TERRA lncRNA to telomeres through R-loops

Joachim Lingner, Thomas Frédéric Lunardi, Marianna Feretzaki, Rita Valador Fernandes

Telomeres-repeated, noncoding nucleotide motifs and associated proteins that are found at the ends of eukaryotic chromosomes-mediate genome stability and determine cellular lifespan1. Telomeric-repeat-containing RNA (TERRA) is a class of long noncoding RNA ...

2020

Observing protein interaction dynamics to chemically defined chromatin fibers by colocalization single-molecule fluorescence microscopy

Beat Fierz, Maxime Nicolas Mivelaz

In eukaryotic cells, the genome is packaged into chromatin and exists in different states, ranging from open euchromatic regions to highly condensed heterochromatic regions. Chromatin states are highly dynamic and are organized by an interplay of histone p ...

2020

KAP1 targets actively transcribed genomic loci to exert pleomorphic effects on RNA polymerase II activity

Didier Trono, Evaristo Jose Planet Letschert, Marco Cassano, Annamaria Kauzlaric, Suk Min Jang

KAP1 (KRAB-associated protein 1) is best known as a co-repressor responsible for inducing heterochromatin formation, notably at transposable elements. However, it has also been observed to bind the transcription start site of actively expressed genes. To a ...

2020

KAP1 is an antiparallel dimer with a functional asymmetry

Didier Trono, Matteo Dal Peraro, Beat Fierz, Davide Demurtas, Louise Catherine Bryan, Maria Josefina Marcaida Lopez, Giulia Fonti, Pierre-Yves Joseph Laurent Helleboid, Alexandra Styliani Kalantzi

KAP1 (KRAB domain-associated protein 1) plays a fundamental role in regulating gene expression in mammalian cells by recruiting different transcription factors and altering the chromatin state. In doing so, KAP1 acts both as a platform for macromolecular i ...

Life Science Alliance, LLC2019

Functional analysis of the telomeric long non-coding RNA TERRA

Patricia Renck Nunes

Telomeres are nucleoprotein structures present in the end of linear chromosomes. In humans, a core complex of 6 proteins cap and protect the chromosome ends from being recognized as double-strand breaks and eliciting unwanted DNA damage and repair response ...

EPFL2019

Structural and functional characterisation of the KRAB-domain associated protein 1

Giulia Fonti

KAP1 (KRAB-domain associated protein 1) plays a fundamental role in regulating gene expression in mammalian cells by recruiting different transcription factors and altering the chromatin state. In doing so, KAP1 acts both as a platform for macromolecular i ...

EPFL2019

Chemical and biophysical methods to explore dynamic mechanisms of chromatin silencing

Beat Fierz, Iuliia Boichenko

Chromatin, the nucleoprotein complex organizing the genome, is central in regulating gene expression and genome organization. Chromatin conformational dynamics, controlled by histone post-translational modifications (PTM) and effector proteins, play a key ...

2019

Beyond silence : a functional and evolutionary study of KRAB zinc finger proteins

Pierre-Yves Joseph Laurent Helleboid

Transposable elements (TEs) are genetic units capable of spreading within the genomes of their host. TEs contribute a readily recognizable 45% of the human DNA, reflecting in part their co-option for some as source of protein-coding sequences, for others a ...

EPFL2019

Dynamic regulation of chromatin accessibility by pluripotency transcription factors across the cell cycle

Bart Deplancke, David Michael Suter, Cédric Deluz, Vincent Roland Julien Gardeux, Antonio Carlos Alves Meireles Filho, Torgil Elias Friman, Subashika Govindan

The pioneer activity of transcription factors allows for opening of inaccessible regulatory elements and has been extensively studied in the context of cellular differentiation and reprogramming. In contrast, the function of pioneer activity in self-renewi ...

2019

Chromatin Fiber Invasion and Nucleosome Displacement by the Rap1 Transcription Factor

Rudolf Hovius, Beat Fierz, Iuliia Boichenko, Maxime Nicolas Mivelaz, Anne-Marinette Thi Phuong Hanh Cao

Pioneer transcription factors (pTFs) bind to target sites within compact chromatin, initiating chromatin remodeling and controlling the recruitment of downstream factors. The mechanisms by which pTFs overcome the chromatin barrier are not well understood. ...

2020