Publications by authors named "Jean Christophe Andrau"

There is growing evidence that a wide range of human diseases and physiological traits are influenced by genetic variation of cis-regulatory elements. We and others have shown that a subset of promoter elements, termed Epromoters, also function as enhancer regulators of distal genes. This opens a paradigm in the study of regulatory variants, as single nucleotide polymorphisms (SNPs) within Epromoters might influence the expression of several (distal) genes at the same time, which could disentangle the identification of disease-associated genes.

View Article and Find Full Text PDF

Objective: To analyze the lymphocyte subsets in individuals with Kabuki syndrome for better characterizing the immunological phenotype of this rare congenital disorder.

Methods: We characterized the immunological profile including B-, T- and natural killer-cell subsets in a series (N = 18) of individuals with Kabuki syndrome.

Results: All 18 individuals underwent genetic analysis: 15 had a variant in KMT2D and 3 a variant in KDM6A.

View Article and Find Full Text PDF
Article Synopsis
  • Understanding the molecular mechanisms of carcinogenesis is vital for cancer treatment, as tumorigenesis involves various genetic factors and disease characteristics.
  • The B-MYB gene, which plays a role in cell cycle regulation, can become an oncogene through mutations and is linked to poor outcomes in cancers like lung cancer.
  • This study explores the G-quadruplex (G4) structures in the B-MYB gene promoter, suggesting new avenues for targeting this gene in cancer therapy.
View Article and Find Full Text PDF

The largest subunit of RNA polymerase (Pol) II harbors an evolutionarily conserved C-terminal domain (CTD), composed of heptapeptide repeats, central to the transcriptional process. Here, we analyze the transcriptional phenotypes of a CTD-Δ5 mutant that carries a large CTD truncation in human cells. Our data show that this mutant can transcribe genes in living cells but displays a pervasive phenotype with impaired termination, similar to but more severe than previously characterized mutations of CTD tyrosine residues.

View Article and Find Full Text PDF

Metazoan promoters are enriched in secondary DNA structure-forming motifs, such as G-quadruplexes (G4s). Here we describe 'G4access', an approach to isolate and sequence G4s associated with open chromatin via nuclease digestion. G4access is antibody- and crosslinking-independent and enriches for computationally predicted G4s (pG4s), most of which are confirmed in vitro.

View Article and Find Full Text PDF

Signal transduction pathways often involve transcription factors that promote activation of defined target gene sets. The transcription factor RBPJ is the central player in Notch signaling and either forms an activator complex with the Notch intracellular domain (NICD) or a repressor complex with corepressors like KYOT2/FHL1. The balance between these two antagonizing RBPJ-complexes depends on the activation state of the Notch receptor regulated by cell-to-cell interaction, ligand binding and proteolytic cleavage events.

View Article and Find Full Text PDF

To maintain cellular identities during development, gene expression profiles must be faithfully propagated through cell generations. The reestablishment of gene expression patterns upon mitotic exit is mediated, in part, by transcription factors (TF) mitotic bookmarking. However, the mechanisms and functions of TF mitotic bookmarking during early embryogenesis remain poorly understood.

View Article and Find Full Text PDF

Chronic hepatitis C carries a high risk of development of hepatocellular carcinoma (HCC), triggered by both direct and indirect effects of the virus. We examined cell-autonomous alterations in gene expression profiles associated with hepatitis C viral presence. Highly sensitive single molecule fluorescent in situ hybridization applied to frozen tissue sections of a hepatitis C patient allowed the delineation of clusters of infected hepatocytes.

View Article and Find Full Text PDF

MNase-Seq is a genome-wide procedure that allows mapping of DNA associated to nucleosomes following micrococcal nuclease digestion. It is a rapid and robust technology useful for the analysis of chromatin properties genome-wide at the resolution of mono-nucleosomes. Here, we describe how to produce high-resolution nucleosome maps of cells grown in suspension or adherent mammalian cells.

View Article and Find Full Text PDF

Promoter-proximal pausing of RNA polymerase II is a key process regulating gene expression. In latent HIV-1 cells, it prevents viral transcription and is essential for latency maintenance, while in acutely infected cells the viral factor Tat releases paused polymerase to induce viral expression. Pausing is fundamental for HIV-1, but how it contributes to bursting and stochastic viral reactivation is unclear.

View Article and Find Full Text PDF
Article Synopsis
  • The AP-1 family, consisting of Fos and Jun proteins, plays a crucial yet unclear role in transcription regulation, particularly in triple negative breast cancers (TNBC), where Fra-1 is overexpressed and contributes to tumor aggressiveness.
  • A combination of advanced techniques, like transcriptomics and machine learning, revealed that both Fra-1 and Fra-2 regulate numerous genes, influencing various biological processes through their binding to regulatory elements far from gene promoters, impacting transcription regulation.
  • The study indicates that while Fra-1 doesn't significantly affect chromatin structure at target genes, it may enhance interactions between bound and unbound elements within chromatin, altering our understanding of AP-1's role
View Article and Find Full Text PDF

During thymic development and upon peripheral activation, T cells undergo extensive phenotypic and functional changes coordinated by lineage-specific developmental programs. To characterize the regulatory landscape controlling T cell identity, we perform a wide epigenomic and transcriptional analysis of mouse thymocytes and naive CD4 differentiated T helper cells. Our investigations reveal a dynamic putative enhancer landscape, and we could validate many of the enhancers using the high-throughput CapStarr sequencing (CapStarr-seq) approach.

View Article and Find Full Text PDF
Article Synopsis
  • The Ikzf1 gene is crucial for T and B cell differentiation, and its mutations are linked to leukemia.
  • Researchers identified several regulatory regions near the Ikzf1 gene, particularly focusing on an enhancer located 120 kb upstream, to understand gene expression control.
  • Deleting the identified E120 enhancer significantly decreased Ikzf1 mRNA levels but only minimally altered the overall regulatory landscape, indicating a complex system governing Ikzf1 expression.
View Article and Find Full Text PDF

Genetic syndromes frequently present with overlapping clinical features and inconclusive or ambiguous genetic findings which can confound accurate diagnosis and clinical management. An expanding number of genetic syndromes have been shown to have unique genomic DNA methylation patterns (called "episignatures"). Peripheral blood episignatures can be used for diagnostic testing as well as for the interpretation of ambiguous genetic test results.

View Article and Find Full Text PDF

Naive CD4 T lymphocytes differentiate into different effector types, including helper and regulatory cells (Th and Treg, respectively). Heritable gene expression programs that define these effector types are established during differentiation, but little is known about the epigenetic mechanisms that install and maintain these programs. Here, we use mice defective for different components of heterochromatin-dependent gene silencing to investigate the epigenetic control of CD4 T cell plasticity.

View Article and Find Full Text PDF
Article Synopsis
  • Kabuki syndrome (KS) is a rare genetic disorder marked by distinctive facial features, intellectual disability, and various physical malformations.
  • In a study involving 177 individuals with KS, significant percentages displayed immunopathological issues: 44.1% had infection susceptibility, 58.2% had low immunoglobulin levels, and there were notable occurrences of autoimmune diseases.
  • The findings underscore the critical need for regular screening and preventive care for these potentially serious health issues in KS patients.
View Article and Find Full Text PDF

L1 retrotransposons are transposable elements and major contributors of genetic variation in humans. Where L1 integrates into the genome can directly impact human evolution and disease. Here, we experimentally induced L1 retrotransposition in cells and mapped integration sites at nucleotide resolution.

View Article and Find Full Text PDF

Mammalian-wide interspersed repeats (MIRs) are retrotransposed elements of mammalian genomes. Here, we report the specific binding of zinc finger protein ZNF768 to the sequence motif GCTGTGTG (N20) CCTCTCTG in the core region of MIRs. ZNF768 binding is preferentially associated with euchromatin and promoter regions of genes.

View Article and Find Full Text PDF

The transcription factor PLZF (promyelocytic leukemia zinc finger protein) acts as an epigenetic regulator balancing self-renewal and differentiation of hematopoietic cells through binding to various chromatin-modifying factors. First described as a transcriptional repressor, PLZF is also associated with active transcription, although the molecular bases underlying the differences are unknown. Here, we reveal that in a hematopoietic cell line, PLZF is predominantly associated with transcribed genes.

View Article and Find Full Text PDF

The carboxy-terminal domain (CTD) of RNA polymerase (Pol) II is composed of a repetition of YSPTSPS heptads and functions as a loading platform for protein complexes that regulate transcription, splicing, and maturation of RNAs. Here, we studied mammalian CTD mutants to analyze the function of tyrosine1 residues in the transcription cycle. Mutation of 3/4 of the tyrosine residues (YFFF mutant) resulted in a massive read-through transcription phenotype in the antisense direction of promoters as well as in the 3' direction several hundred kilobases downstream of genes.

View Article and Find Full Text PDF

Termination of transcription is important for establishing gene punctuation marks. It is also critical for suppressing many of the pervasive transcription events occurring throughout eukaryotic genomes and coupling their RNA products to efficient decay. In human cells, the ARS2 protein has been implicated in such function as its depletion causes transcriptional read-through of selected gene terminators and because it physically interacts with the ribonucleolytic nuclear RNA exosome.

View Article and Find Full Text PDF

Pioneer transcription factors are defined by their ability to bind nucleosome-occupied regions. Here, we discuss the properties of nucleosomes bound by pioneers at enhancer regions. We describe how select pioneers bind nucleosome-occupied or -depleted enhancer sites.

View Article and Find Full Text PDF

NFATc1 plays a critical role in double-negative thymocyte survival and differentiation. However, the signals that regulate Nfatc1 expression are incompletely characterized. Here we show a developmental stage-specific differential expression pattern of Nfatc1 driven by the distal (P1) or proximal (P2) promoters in thymocytes.

View Article and Find Full Text PDF

Unlabelled: We describe an R package designed for processing aligned reads from chromatin-oriented high-throughput sequencing experiments. Pasha (preprocessing of aligned sequences from HTS analyses) allows easy manipulation of aligned reads from short-read sequencing technologies (ChIP-seq, FAIRE-seq, MNase-Seq, …) and offers innovative approaches such as ChIP-seq reads elongation, nucleosome midpoint piling strategy for positioning analyses, or the ability to subset paired-end reads by groups of insert size that can contain biologically relevant information.

Availability And Implementation: Pasha is a multi-platform R package, available on CRAN repositories under GPL-3 license (https://cran.

View Article and Find Full Text PDF