Abstract
The proprotein convertase enzyme FURIN promotes the proteolytic maturation of pro-proteins and thereby it serves as an important factor for maintaining cellular homeostasis. In T cells, FURIN is critical for maintaining the T regulatory cell dependent peripheral immune tolerance and intact T helper cell polarization. The enzymatic activity of FURIN is directly associated with its expression levels, but genetic determinants for cell-type specific Furin gene regulation have remained elusive. By exploring the histone acetyltransferase p300 binding patterns in T helper cells, a putative regulatory region at ca. 20kB upstream of Furin gene was identified. When this region was deleted with CRISPR/Cas9 the production of Furin mRNA was significantly reduced in activated mouse T cells. Genome-wide RNA profiling by sequencing revealed that the novel Furin regulator region also impacted the expression of several genes that have previously been associated with the Th1 type hall mark cytokine IFNγ regulation or function. Finally, Furin genetic regulatory region was found to specifically promote the secretion of IFNγ by activated T cells. In sum, our data unravels the presence of Furin expression regulatory region in T cells that has characteristics of a super-enhancer for Th1 cell fate.
Highlights
The enzymes of the proprotein convertase subtilisin/kexin (PCSK) family are characterized by their common domain structure and unique cleavage target sequence (R/K)X(R/K) where X represents a 0, 2, 4, or 6 amino acid long spacer [1]
ChIP-seq using antibody against the acetyltransferase and transcriptional coactivator p300 protein predicts the presence of active enhancers with high accuracy, more p300 binding referring to higher transcriptional activity of a target gene [40]. p300 has a dual role in the regulation of gene expression: as a chromatinmodification enzyme it can regulate chromatin accessibility, and by recruiting transcription factors it can help in the assembling of the transcriptional machinery
Genes determining cell identity are associated with super-enhancers, which are marked by exceptionally high p300 binding
Summary
The enzymes of the proprotein convertase subtilisin/kexin (PCSK) family are characterized by their common domain structure and unique cleavage target sequence (R/K)X(R/K) where X represents a 0, 2, 4, or 6 amino acid long spacer [1]. Super-enhancers or stretch enhancers (SE) are clusters of putative enhancers, binding transcriptional coactivators on an average 10-fold higher density than typical enhancers (TE) [22,23,24] They can be identified using the Rank Ordering of Superenhancer (ROSE) algorithm on the basis of active enhancer marks such as histone three acetylation on lysine 27 residue (H3K27ac), mediator complex subunit 1 (MED1), and binding of lineage-specific or master transcription factors [23, 24], exceeding H3K27 acetylation level being highly efficient in super-enhancer demarcation [22, 25]. A recent study found exceedingly high histone acetyltransferase p300 binding in close genomic proximity to Furin gene in mouse Th1 cells [29], suggesting the presence of a super-enhancer in this cell type. We have used CRISPR/Cas genome-editing technology to functionally characterize this putative superenhancer region in T cell activation and cytokine production
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
