Active Motif's Podcast

In this episode of the Epigenetics Podcast, we talked with Sven Heinz from the University of California in San Diego about his work on the impact of sequence variation on transcription factor binding affinities and genetic diversity. Sven Heinz talks about a landmark study published in Nature that examined the impact of sequence variation on transcription factor binding affinities and downstream effects on gene expression. Modifying genetic sequences to understand the influence of different motifs provided valuable insights into how genetic variation shapes cellular responses and gene expression patterns, underscoring the importance of genetic diversity. Methodological approaches using inducible systems to observe changes in transcription factor binding patterns highlight the critical role of motif variation and redundancy in transcription factor families. These studies provide essential insights into the complex network of transcriptional regulation and chromatin dynamics, revealing the nuanced mechanisms th

In this episode of the Epigenetics Podcast, we talked with Sarah Marzi from the UK Dementia Research Institute at Imperial College London about her work on epigenetic changes in Alzheimer's Disease, and comparing CUT&Tag to ENCODE ChIP-Seq using limited cell samples. The interview discusses Sarah Marzi's work on ChIP-Seq experiments and their significance in understanding Alzheimer's disease from an epigenetic perspective. The discussion touches on the widespread dysregulation and changes in acetylation, particularly in genes associated with Alzheimer's risk, providing insights into potential links between epigenetic insults and disease onset. Moving on to the technical aspects of the study, the interview examines the strategic use of CUT&Tag. It explores the challenges and optimizations involved in accurately profiling limited cell samples. The dialogue also compares CUT&Tag to ENCODE ChIP-Seq, highlighting the complexities of peak calling and data interpretation across different methodologies.  

In this episode of the Epigenetics Podcast, we talked with Mark Parthun from Ohio State University about his work on the role of Hat1p in chromatin assembly. Mark Parthun shares insights into his pivotal paper in 2004 that explored the link between type B histone acetyltransferases and chromatin assembly, setting the stage for his current research interests in epigenetics. He highlights the role of HAT1 in acetylating lysines on newly synthesized histones, its involvement in double-strand break repair, and the search for phenotypes associated with HAT1 mutations. The discussion expands to a collaborative research project between two scientists uncovering the roles of HAT1 and NASP as chaperones in chromatin assembly. Transitioning from yeast to mouse models, the team investigated the effects of HAT1 knockout on mouse phenotypes, particularly in lung development and craniofacial morphogenesis. They also explored the impact of histone acetylation on chromatin dynamics and its influence on lifespan, aging proces

In this episode of the Epigenetics Podcast, we talked with Upasna Sharma from UC Santa Cruz about her work on a number of interesting projects on H2A.Z and telomeres, the impact of paternal diet on offspring metabolism, and the role of small RNAs in sperm. In this interview Upasna Sharma discusses her work on the study of the paternal diet's impact on offspring metabolism. She reveals the discovery of small non-coding RNAs, particularly tRNA fragments, in mature mammalian sperm that may carry epigenetic information to the next generation. She explains the specific alterations in tRNA fragment levels in response to a low-protein diet and the connections found between tRNA fragments and metabolic status. Dr. Sharma further explains the degradation and stabilization of tRNA fragments in cells and the processes involved in their regulation. She shares their observation of tRNA fragment abundance in epididymal sperm, despite the sperm being transcriptionally silent at that time. This leads to a discussion on the r

In this episode of the Epigenetics Podcast, we talked with Weiwei Dang from Baylor College of Medicine about his work on molecular mechanisms of aging and the role of H3K36me3 and cryptic transcription in cellular aging. The team in the Weiwei Dang lab explored the connection between histone marks, specifically H4K16 acetylation and H3K36 methylation, and aging. Dr. Dang describes how the lab conducted experiments by mutating H4K16 to determine its effect on lifespan. They observed that the mutation to glutamine accelerated the aging process and shortened lifespan, providing causal evidence for the relationship between H4K16 and lifespan. They also discovered that mutations in acetyltransferase and demethylase enzymes had opposite effects on lifespan, further supporting a causal relationship. Weiwei Dang then discusses their expanded research on aging, conducting high-throughput screens to identify other histone residues and mutants in yeast that regulate aging. They found that most mutations at K36 shortened

In this episode of the Epigenetics Podcast, we talked with Mitch Guttman from California Institute of Technology about his work on characterising the 3D interactions of the genome using Split-Pool Recognition of Interactions by Tag Extension (SPRITE). Mitch Guttman discusses his exploration of the long non-coding RNA Xist, which plays a crucial role in X chromosome inactivation. He explains how they discovered that Xist is present everywhere in the nucleus, not just in specific locations on the X chromosome. Through their research, they identified critical proteins like SHARP that are involved in X chromosome silencing. The discussion then shifts to SPRITE, a method they developed to map multi-way contacts and generalize beyond DNA to include RNA and proteins. They compare SPRITE to classical proximity ligation methods like Hi-C and discuss how cluster sizes in SPRITE can estimate 3D distances between molecules. The conversation also touches upon the potential of applying SPRITE to single-cell experiments, al

In this episode of the Epigenetics Podcast, we talked with Yali Dou from Keck School of Medicine of USC about her work on MLL Proteins in Mixed-Lineage Leukemia. To start off this Interview Yali describes her early work on MLL1 and its function in transcription, particularly its involvement in histone modification. She explains her successful purification of the MLL complex and the discovery of MOF as one of the proteins involved. Next, the interview focuses on her work in reconstituting the MLL core complex and the insights gained from this process. She shares her experience of reconstituting the MLL complex and discusses her focus on the crosstalk of H3K4 and H3K79 methylation, regulated by H2BK34 ubiquitination. The podcast then delves into the therapeutic potential of MLL1, leading to the discovery of a small molecule inhibitor. Finally, we talk about the importance of the protein WDR5 in the assembly of MLL complexes and how targeting the WDR5-ML interaction can inhibit MLL activity.   References Dou, Y

In this episode of the Epigenetics Podcast, we talked with Sam Buckberry from the Telethon Kids Institute about his work on gene imprinting, sex-biased gene expression, DNA regulatory landscapes, and genomics in the indigenous population of Australia. Sam Buckberry's research career started with working on the imprinting of H19, IGF2, and IGF2R genes in the placenta. We talk about the controversy surrounding the imprinting of IGF2R and how his study used pyrosequencing to quantify gene expression. We also discuss Sam's work on sex-biased gene expression in the placenta and the identification of a cluster of genes related to placental development and pregnancy. In addition, we talk about Sam's research on reprogramming and the characterization of DNA regulatory landscapes during the process. We discuss the challenges of working with sequencing data, the discovery of epigenetic memories, and erasing them during reprogramming. Towards the end of the conversation, Sam mentions his current work in setting up an ep

In this episode of the Epigenetics Podcast, we talked with Kyle Eagen from Baylor College of Medicine about his work on BET Proteins and their role in chromosome folding and compartmentalization. In the early days of his research career Dr. Eagen made use of genomics and microscopy to study chromosomes, particularly polytene chromosomes in Drosophila. The correlation between the folding patterns detected by Hi-C and polytene bands highlights the similarities between the two, bridging traditional cytology with modern NGS methods. This work formed the basis of Kyle's thesis and sparked his interest in nuclear organization and chromosome 3D structure. In his independent lab Kyle then studied compartments in chromatin structure and focused on the relationship between histone modifications and the 3D structure of chromosomes. The discovery of BRD4-NUT, a fusion oncoprotein that reprograms chromosome 3D structure, is highlighted as a significant step forward in understanding chromatin structure. The conversation th

In this episode of the Epigenetics Podcast, we talked with Francesca Telese from UC San Diego and Jessica Zhou from Cold Spring Harbour about their work on the molecular underpinnings of human addiction. Francesca Telese worked on neuronal enhancers and their pivotal role in governing gene activity. She sheds light on her remarkable findings concerning the epigenetic signature of neuronal enhancers that are intricately involved in synaptic plasticity. Jessica Zhou joined Francesca Telese's lab as a PhD student where she worked on elucidating the effects of chronic cannabis use on memory and behavior in mice. She takes us through the fascinating correlation between THC and gene co-expression networks. Francesca and Jessicathen discuss the utilization of genetically diverse outbred rats in their research, along with the crucial exploration of cell type specificity in gene expression studies. They then delve into the long-term changes that occur in the brain after drug exposure and the profound implications for

In this episode of the Epigenetics Podcast, we talked with Tanja Vogel from the University Clinics Freiburg about her work on epigenetic modifications in stem cells during central nervous system development. During our discussion, Dr. Vogel shared that she and her team have investigated H3K79 methylation and its functional significance, which remains a topic of debate in the scientific community. They’ve also investigated the role of DOT1L in neural development and its implications for neuronal networks, as disrupting DOT1L can lead to conditions such as epilepsy and schizophrenia. They explored the function of the SOX2 enhancer in the presence or absence of DOT1L enzymatic inhibition. The conversation then shifts to FoxG1, a vital player in forebrain development. The team uncovered its role in chromatin accessibility and its connection to microRNA processing. Their study, utilizing ChIP-Seq, reveals FoxG1's interactions with enhancer regions and other transcription factors, like NeuroD1.   ### References Br

In this episode of the Epigenetics Podcast, we talked with Maria Gambetta from the University of Lausanne about her work on the function of insulators in 3D genome folding. Maria Gambetta focuses on investigating 3D contact dynamics between enhancers and promoters, providing insights into tissue-specific gene activation. The team used capture-C to analyze dynamic looping events, emphasizing the significance of accessible chromatin peaks in enhancer-promoter interactions. Furthermore, they focused on gene insulation and CTCF's role in forming topologically associating domains in Drosophila. Hi-C analysis on CTCF mutants revealed the conservation of TAD boundary mechanisms, identifying CP-190 as a potential binding protein. Their findings on the loss of TAD boundaries in mutants and the role of transcription in TAD boundary formation are discussed as well as the function of CP190 and insulators in preventing interactions between promoters and enhancers. Their work challenges existing models of insulator functio

In this episode of the Epigenetics Podcast, we talked with Jason Carroll from the Cambridge Research Institute about his work on contribution of estrogen receptor to breast cancer progression. The Podcast centers around the crucial role of the forkhead protein FOXA1 in breast cancer. FOXA1 acts as a pioneer transcription factor, facilitating gene regulation by recruiting nuclear receptors to chromatin, profoundly influencing gene expression in various breast cancer subtypes. The FOXA1-positive subtype of triple-negative breast cancer, despite being estrogen receptor-negative, shares gene expression profiles with estrogen receptor-positive breast cancer, shedding light on the importance of targeting the androgen receptor for treatment. The challenges of studying transcription factor mappings from clinical samples are explored, with a focus on the ChIP-seq method's success in mapping estrogen receptor binding sites. Various techniques for transcription factor mapping, including CUT&RUN, CUT&Tag, and ChI

In this episode of the Epigenetics Podcast, we caught up with Sheila Teves from the University of British Columbia to talk about her work on the inheritance of transcriptional memory by mitotic bookmarking. Early in her research career, Sheila Teves focused on the impact of nucleosomes on torsional stress and gene regulation. She also highlights the development of a genome-wide approach to measure torsional stress and its relationship to nucleosome dynamics and RNA polymerase regulation. The conversation then shifts to her focus on transcriptional memory and mitotic bookmarking during her postdoc in the Tijan lab. She explores the concept of mitotic bookmarking, whereby certain transcription factors remain bound to their target sites during mitosis, facilitating efficient reactivation of transcription after cell division. She discusses her findings on the behavior of transcription factors on mitotic chromosomes, challenging the notion that they are excluded during mitosis. She also discusses the differences i

In this episode of the Epigenetics Podcast, we talked with Janine La Salle from UC Davis about her work on differential methylated regions in autism spectrum disorders. In our discussion, Janine LaSalle highlights her work on the placental epigenetic signature, which offers insights into the impact of fetal exposures and gene-environment interactions during the perinatal period. She emphasizes the placenta's value as a surrogate tissue for understanding human diseases. Her research on DNA methylation in the placenta across different mammalian species reveals consistent patterns in partially methylated and highly methylated domains. She explains the critical role of higher methylation levels in specific regions for gene expression and how this knowledge helps trace the placenta's developmental history. The conversation then delves into Dr. LaSalle's research on the link between placental DNA methylation and autism. Through epigenome-wide association studies, she discovered a novel autism gene and explored the

In this episode of the Epigenetics Podcast, we caught up with Björn Schumacher from the Institute for Genome Stability in Ageing and Disease at the University of Cologne to talk about his work on DNA damage in longevity and ageing. In this episode Björn Schumacher discusses his research on DNA repair and its impact on ageing. We explore his insights on the effects of DNA damage on transcription, the importance of studying development, and the role of histone modifications. We also discuss paternal DNA damage inheritance and the DREAM complex as a master regulator of DNA repair. The lab’s goal is to enhance somatic DNA repair for healthier ageing and disease prevention.   References Schumacher, B., van der Pluijm, I., Moorhouse, M. J., Kosteas, T., Robinson, A. R., Suh, Y., Breit, T. M., van Steeg, H., Niedernhofer, L. J., van Ijcken, W., Bartke, A., Spindler, S. R., Hoeijmakers, J. H., van der Horst, G. T., & Garinis, G. A. (2008). Delayed and accelerated aging share common longevity assurance mechanisms

In this episode of the Epigenetics Podcast, we talked with Capucine van Rechem from Stanford University about her work on the impact of chromatin modifiers on disease development and progression. During her postdoctoral work, Capucine van Rechem studied the effects of Single nucleotide polymorphisms (SNPs) in KDM4A on lung cancer cell lines and discovered a link between KDM4A and mTOR. She found that cells with the SNP had decreased KDM4A levels and increased sensitivity to inhibitors of the translation pathway. In addition, she found that a combination of histone marks was more predictive of replication timing than RNA expression alone, and identified the specific stages of the cell cycle where KDM4 primarily acts. Now in her own lab, the focus of her work shifted to SWI-SNF. The team has discovered the role of SWI-SNF in translation through polysome profiling and confirmed the interaction between SWI-SNF and translation. They are currently working to understand the functions of different complexes in tran

In this episode of the Epigenetics Podcast, we caught up with Luca Giorgetti from the Friedrich Miescher Institute to hear about his work on long-range transcriptional control by 3D chromosome structure. Luca Giorgetti's research focuses on chromosomal interactions, transcriptional output, and the dynamics of enhancer-promoter relationships. His lab investigated the causal relationship between chromosome interactions and transcriptional events. They’ve found that by manipulating the contact probabilities between an enhancer and a promoter by changing their distance, these changes had a substantial effect on transcription levels. This project was an experiment that Luca Giorgetti was eager to do, and it allowed him to establish a smooth functional relationship between contact probabilities and changes in transcription levels.   References Giorgetti, L., Galupa, R., Nora, E. P., Piolot, T., Lam, F., Dekker, J., Tiana, G., & Heard, E. (2014). Predictive polymer modeling reveals coupled fluctuations in chrom

In this episode of the Epigenetics Podcast, we talked with Mary Gehring from MIT about her work on transgenerational inheritance and epigenetic imprinting in plants. Mary Gehring and her team are focusing on plant epigenetics and genetic imprinting in plants, studying DNA methylation in Arabidopsis. They have found significant differences in DNA methylation between the embryo and endosperm of plants, particularly in relation to imprinted genes. She also discusses their work on hydroxymethylcytosine (5-hmC) in Arabidopsis and the challenges of detecting and studying this epigenetic modification. Next, we discuss the regulatory circuit involving ROS1, a DNA glycosylase involved in demethylation, and its role in maintaining epigenetic homeostasis. The interview concludes with a discussion of CUT&RUN, which the lab has adapted for use in plants. Due to its low input requirements this method has been valuable in studying various plant tissues and has influenced Mary Gehring's research on imprinting in Arabidop

In this episode of the Epigenetics Podcast, we talked to Claudio Cantù from Linköping University about his work on peak blacklists, peak concordance and what is a peak in CUT&RUN. Our host Stefan Dillinger and guest Claudio Cantù dive into the topic of when we can be sure that a peak is a peak. To help with this, Claudio Cantù's group has been working on defining a set of suspicious peaks that can be used as a "peak blacklist" and can be subtracted to clean up CUT&RUN data sets. The lab also worked on a method called ICEBERG (Increased Capture of Enrichment By Exhaustive Replicate aGgregation) to help define peaks from a number of experimental replicates. By using this algorithm, the team is trying to discover the beta-catenin binding profile, not the tip of the beta-catenin binding iceberg, but the whole of the beta-catenin binding profile.   References Zambanini, G., Nordin, A., Jonasson, M., Pagella, P., & Cantù, C. (2022). A new CUT&RUN low volume-urea (LoV-U) protocol optimized for trans