Related Experiment Video
Updated: May 18, 2026

Describing a Transcription Factor Dependent Regulation of the MicroRNA Transcriptome
Published on: June 15, 2016
Effects of endogenous proteins and microRNA target sequence in a positive feedback system
Genki N Kanda1, Ryohei Togashi, Hideyoshi Harashima
1Faculty of Pharmaceutical Sciences, Hokkaido University, Sapporo, Japan.
Abstract:
A positive feedback system, using GAL4-vp16 (a fusion protein of yeast GAL4 and herpes simplex virus vp16) as an activator and firefly luciferase as a reporter, maintained luciferase expression for 7 d in mice. However, the luciferase expression decreased after 7 d, and this phenomenon could be caused by immunoreactions against these exogenous proteins. This hypothesis was examined by the following three strategies, designed to avoid the putative immunoreactions: (i) use of the endogenous secreted alkaline phosphatase (SEAP) protein as a reporter, (ii) replacement of vp16 with endogenous transcription factors, and (iii) insertion of the target sequence of microRNA expressed in cells of hematopoietic origin, to suppress GAL4-vp16 expression in antigen-presenting cells. The results obtained in this study suggested that silencing would be induced by mechanism(s) besides immunoreactions against reporter and activator proteins.
Related Concept Videos
MicroRNAs
MicroRNAs
MicroRNAs
Cell Signaling Feedback Loops
Negative feedback loops
Most signaling systems have negative feedback loops that can perform different functions such as output limiter, and adaptation.
Output limiter
Upon receiving an input signal, the cellular response rapidly increases until a threshold is reached. Beyond this threshold, a negative feedback loop...
Positive and Negative Feedback Loops
Regulation of Expression at Multiple Steps

