MicroRNA, noise, and gene expression regulation

Abstract

Gene regulatory network that determines the cellular functions exhibits stochastic fluctuations, or “noise,” in different layers. Noise has begun to be appreciated for many previously unrecognized functions in important cellular activities. In fact, molecular noise is unavoidable in both microbial and eukaryotic cells, the feedback system is established evolutionally to reduce noise or optimize the noise for cellular homeostasis. The small noncoding RNAs, particularly, microNRAs, post-transcriptionally and negatively regulate gene expressions. MicroRNAs function as a novel layer to buffer noise level, and stabilize mRNA and protein level to maintain normal cellular function. Furthermore, the changing of microRNA expression levels may increase the stochastic fluctuation leading to abnormal cellular function, even diseases.