Related Experiment Video
Updated: Mar 14, 2026
A Reporter Assay to Analyze Intronic microRNA Maturation in Mammalian Cells
Published on: June 16, 2022
miR-483 is a self-regulating microRNA and can activate its own expression via USF1 in HeLa cells
Verena Vanessa Emmerling1, Simon Fischer2, Michael Kleemann2
1Department of Gene Therapy, Ulm University, Helmholtz Strasse 8/1, 89081 Ulm, Germany.
Abstract:
MicroRNAs (miRNAs) are small non-coding RNAs that constitute a fundamental part of post-transcriptional gene regulation in mammalian cells. We have recently identified the intronic miR-483, which functions as an important regulator of protein synthesis during mild hypothermia in human and rodent cells. Since only very little is known about transcriptional regulation of intronic miRNAs and their host genes, we thoroughly investigated the regulation of miR-483 expression and its host gene IGF2 in HeLa cells. We demonstrate that miR-483 is regulated and expressed independently of its host gene IGF2 during mild hypothermia. Strikingly, we also discovered that miR-483 enhances its own transcription by up-regulation of the transcription factor USF1, which activates a promoter element upstream of the MIR483 gene. However, since the USF1 mRNA lacks binding sites for miR-483-5p and -3p, USF1 expression is likely enhanced in an indirect manner. Our results suggest that miR-483 may self-regulate its own expression independently of its host gene IGF2 in human HeLa cells. This points towards a novel feed-forward mechanism, in which selected intronic miRNAs may activate their own expression by transcriptional activation of upstream regulators.
Insights
MicroRNAs (miRNAs) self-regulate their own transcription, independently of their host gene IGF2, during hypothermia. This novel feed-forward mechanism involves up-regulating transcription factor USF1.
Area of Science:
- Molecular Biology
- Gene Regulation
- Biochemistry
Background:
- MicroRNAs (miRNAs) are key regulators of gene expression.
- Intronic miRNAs, like miR-483, are often linked to their host genes.
- Little is known about the transcriptional regulation of intronic miRNAs and their host genes.
Purpose of the Study:
- Investigate the transcriptional regulation of miR-483 and its host gene IGF2.
- Determine the relationship between miR-483 expression and IGF2 during hypothermia.
- Elucidate the mechanism of miR-483 self-regulation.
Main Methods:
- Analysis of miR-483 and IGF2 expression in HeLa cells under mild hypothermia.
- Investigation of transcription factor USF1 involvement in miR-483 regulation.
- Reporter assays to assess promoter activity.
Main Results:
- miR-483 expression is independent of its host gene IGF2 during mild hypothermia.
- miR-483 enhances its own transcription by up-regulating USF1.
- USF1 activates a promoter element upstream of the MIR483 gene.
- USF1 mRNA lacks direct binding sites for miR-483, suggesting indirect regulation.
Conclusions:
- miR-483 self-regulates its transcription independently of IGF2 in human cells.
- A novel feed-forward mechanism exists where intronic miRNAs activate their own expression.
- This mechanism involves transcriptional activation of upstream regulators like USF1.
More Related Videos
10:43siRNA Screening to Identify Ubiquitin and Ubiquitin-like System Regulators of Biological Pathways in Cultured Mammalian Cells
Published on: May 24, 2014
07:19Identifying Targets of Human microRNAs with the LightSwitch Luciferase Assay System using 3'UTR-reporter Constructs and a microRNA Mimic in Adherent Cells
Published on: September 28, 2011
Related Concept Videos
01:24Regulation of Angiogenesis and Blood Supply
01:15Receptor Downregulation in MVBs
The EGFR can initiate signaling pathways that lead to cell proliferation, migration, and differentiation. Overexpression of EGFR stimulates cells to proliferate. Excessive EGFR...