17 research outputs found
Global and stage specific patterns of KrĂĽppel-associated-box zinc finger protein gene expression in murine early embryonic cells.
Highly coordinated transcription networks orchestrate the self-renewal of pluripotent stem cell and the earliest steps of mammalian development. KRAB-containing zinc finger proteins represent the largest group of transcription factors encoded by the genomes of higher vertebrates including mice and humans. Together with their putatively universal cofactor KAP1, they have been implicated in events as diverse as the silencing of endogenous retroelements, the maintenance of imprinting and the pluripotent self-renewal of embryonic stem cells, although the genomic targets and specific functions of individual members of this gene family remain largely undefined. Here, we first generated a list of Ensembl-annotated KRAB-containing genes encoding the mouse and human genomes. We then defined the transcription levels of these genes in murine early embryonic cells. We found that the majority of KRAB-ZFP genes are expressed in mouse pluripotent stem cells and other early progenitors. However, we also identified distinctively cell- or stage-specific patterns of expression, some of which are pluripotency-restricted. Finally, we determined that individual KRAB-ZFP genes exhibit highly distinctive modes of expression, even when grouped in genomic clusters, and that these cannot be correlated with the presence of prototypic repressive or activating chromatin marks. These results pave the way to delineating the role of specific KRAB-ZFPs in early embryogenesis
A yeast one-hybrid and microfluidics-based pipeline to map mammalian gene regulatory networks
The comprehensive mapping of gene promoters and enhancers has significantly improved our understanding of how the mammalian regulatory genome is organized. An important challenge is to elucidate how these regulatory elements contribute to gene expression by identifying their trans-regulatory inputs. Here, we present the generation of a mouse-specific transcription factor (TF) open-reading frame clone library and its implementation in yeast one-hybrid assays to enable large-scale protein–DNA interaction detection with mouse regulatory elements. Once specific interactions are identified, we then use a microfluidics-based method to validate and precisely map them within the respective DNA sequences. Using well-described regulatory elements as well as orphan enhancers, we show that this cross-platform pipeline characterizes known and uncovers many novel TF–DNA interactions. In addition, we provide evidence that several of these novel interactions are relevant in vivo and aid in elucidating the regulatory architecture of enhancers
GETPrime: a gene- or transcript-specific primer database for quantitative real-time PCR
The vast majority of genes in humans and other organisms undergo alternative splicing, yet the biological function of splice variants is still very poorly understood in large part because of the lack of simple tools that can map the expression profiles and patterns of these variants with high sensitivity. High-throughput quantitative real-time polymerase chain reaction (qPCR) is an ideal technique to accurately quantify nucleic acid sequences including splice variants. However, currently available primer design programs do not distinguish between splice variants and also differ substantially in overall quality, functionality or throughput mode. Here, we present GETPrime, a primer database supported by a novel platform that uniquely combines and automates several features critical for optimal qPCR primer design. These include the consideration of all gene splice variants to enable either gene-specific (covering the majority of splice variants) or transcript-specific (covering one splice variant) expression profiling, primer specificity validation, automated best primer pair selection according to strict criteria and graphical visualization of the latter primer pairs within their genomic context. GETPrime primers have been extensively validated experimentally, demonstrating high transcript specificity in complex samples. Thus, the free-access, user-friendly GETPrime database allows fast primer retrieval and visualization for genes or groups of genes of most common model organisms, and is available at http://updepla1srv1.epfl.ch/getprime/
ZFP30 promotes adipogenesis through the KAP1-mediated activation of a retrotransposon-derived Pparg2 enhancer.
KrĂĽppel-associated box zinc finger proteins (KZFPs) constitute the largest family of mammalian transcription factors, but most remain completely uncharacterized. While initially proposed to primarily repress transposable elements, recent reports have revealed that KFZPs contribute to a wide variety of other biological processes. Using murine and human in vitro and in vivo models, we demonstrate here that one poorly studied KZFP, ZFP30, promotes adipogenesis by directly targeting and activating a retrotransposon-derived Pparg2 enhancer. Through mechanistic studies, we further show that ZFP30 recruits the co-regulator KRAB-associated protein 1 (KAP1), which, surprisingly, acts as a ZFP30 co-activator in this adipogenic context. Our findings provide an understanding of both adipogenic and KZFP-KAP1 complex-mediated gene regulation, showing that the KZFP-KAP1 axis can also function in a non-repressive manner
Gene expression analysis of metastases and tumor host interactions in metastatic lesions in a multistage model of prostate carcinogenesis
Metastasis is a multistep process that represents the final stage in cancer progression and heralds a terminal disease state. Understanding the molecular changes required for the establishment of metastases that are common or specific to a particular location and the corresponding changes in the host tissue response that may support metastasis formation is highly relevant for the cancer management. To address metastatic tumor gene expression, I used a multistage prostate carcinogenesis model and performed affymetrix microarray analysis of laser capture microdissected tumor cells in liver, lung and kidney tissues as well as in primary tumor. By comparing metastatic gene expression profiles with those of the primary tumor, I found candidate genes for organ specificity and a small set of genes shared by metastases at all three locations. These common genes may be relevant to the metastatic process itself, and will require further investigation. To address the host-response gene expression profile to metastatic growth, I performed affymetrix microarray analysis of microdissected liver microenvironment in direct contact with macrometastases and as well of the healthy liver. Comparison of these two microenvironments revealed genes related to a reactive inflammatory response surrounding metastases that may potentially support their growth. The distinct signatures uncovered provide potential clues as to some of the requirements for metastatic establishment and growth where both tumor cells and the surrounding microenvironment play an important role, and open possibilities for future functional analysis and, hopefully, clinical application
Table S2 - RNASeq_ZEB1_KD
Effect of ZEB1 knockdown on global gene expression in 3T3-L1 cells as measured at days 0 and 2
Data from: Identification of ZEB1 as a central component of the adipogenic gene regulatory network
Adipose tissue is a key determinant of whole body metabolism and energy homeostasis. Unraveling the regulatory mechanisms underlying adipogenesis is therefore highly relevant from a biomedical perspective. Our current understanding of fat cell differentiation is centered on the transcriptional cascades driven by the C/EBP protein family and the master regulator PPARÎł. To elucidate further components of the adipogenic gene regulatory network, we performed a large-scale transcription factor (TF) screen overexpressing 734 TFs in mouse pre-adipocytes and probed their effect on differentiation. We identified 23 novel pro-adipogenic TFs and characterized the top ranking TF, ZEB1, as being essential for adipogenesis both in vitro and in vivo. Moreover, its expression levels correlate with fat cell differentiation potential in humans. Genomic profiling further revealed that this TF directly targets and controls the expression of most early and late adipogenic regulators, identifying ZEB1 as a central transcriptional component of fat cell differentiation
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ZFP30 promotes adipogenesis through the KAP1-mediated activation of a retrotransposon-derived Pparg2 enhancer.
KrĂĽppel-associated box zinc finger proteins (KZFPs) constitute the largest family of mammalian transcription factors, but most remain completely uncharacterized. While initially proposed to primarily repress transposable elements, recent reports have revealed that KFZPs contribute to a wide variety of other biological processes. Using murine and human in vitro and in vivo models, we demonstrate here that one poorly studied KZFP, ZFP30, promotes adipogenesis by directly targeting and activating a retrotransposon-derived Pparg2 enhancer. Through mechanistic studies, we further show that ZFP30 recruits the co-regulator KRAB-associated protein 1 (KAP1), which, surprisingly, acts as a ZFP30 co-activator in this adipogenic context. Our findings provide an understanding of both adipogenic and KZFP-KAP1 complex-mediated gene regulation, showing that the KZFP-KAP1 axis can also function in a non-repressive manner