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BioMed Research International
Volume 2016, Article ID 2676282, 10 pages
http://dx.doi.org/10.1155/2016/2676282
Research Article

Effect of Dynamic Interaction between microRNA and Transcription Factor on Gene Expression

1Department of Physics, College of Physics Science and Technology, Xiamen University, Xiamen 361005, China
2School of Mathematics, Liaoning University, Shenyang 110036, China
3Research Center for Computer Simulating and Information Processing of Bio-Macromolecules of Liaoning Province, Shenyang 110036, China
4School of life science, Liaoning University, Shenyang 110036, China
5Department of Mathematics, Shaoxing University, Shaoxing 312000, China
6Zhongshan School of Medicine, Sun Yat-Sen University, Guangzhou 510080, China
7Guangdong Provincial Key Laboratory of Orthopedics and Traumatology, The First Affiliated Hospital of Sun Yat-Sen University, Guangzhou 510000, China
8School of Mathematical and Computational Science, Sun Yat-Sen University, Guangzhou 510275, China

Received 11 August 2016; Accepted 10 October 2016

Academic Editor: Huiming Peng

Copyright © 2016 Qi Zhao et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

MicroRNAs (miRNAs) are endogenous noncoding RNAs which participate in diverse biological processes in animals and plants. They are known to join together with transcription factors and downstream gene, forming a complex and highly interconnected regulatory network. To recognize a few overrepresented motifs which are expected to perform important elementary regulatory functions, we constructed a computational model of miRNA-mediated feedforward loops (FFLs) in which a transcription factor (TF) regulates miRNA and targets gene. Based on the different dynamic interactions between miRNA and TF on gene expression, four possible structural topologies of FFLs with two gate functions (AND gate and OR gate) are introduced. We studied the dynamic behaviors of these different motifs. Furthermore, the relationship between the response time and maximal activation velocity of miRNA was investigated. We found that the curve of response time shows nonmonotonic behavior in Co1 loop with OR gate. This may help us to infer the mechanism of miRNA binding to the promoter region. At last we investigated the influence of important parameters on the dynamic response of system. We identified that the stationary levels of target gene in all loops were insensitive to the initial value of miRNA.