Analysis of motifs in microRNA-transcription factor gene regulatory networks

Download
2014
Sürün, Bilge
MicroRNAs are small non-coding RNA molecules which contain 21-25 nucleotides, and function in post transcriptional regulation by inhibiting the translation of mRNA targets. miRNAs typically affect gene regulation by forming composite feed forward circuits (cFFCs) which also comprise a transcription factor (TF) and a target gene. By analyzing these cFFCs, the contribution of miRNAs in altering TF networks can be revealed. These contributions could either be the de-escalation of the target gene repertoire or to increase the redundancy through cFFC formation. To conduct the analysis, the connections between genes, miRNAs, and TFs are obtained using two datasets one of which is obtained from human myeloid leukemia cell line. These two datasets are also different from each other in terms of the numbers of TFs and miRNAs that are included in the networks and the significance of the predicted connections. The first dataset which contains connectivity information of a normal cell involves 83 TFs, 564 miRNAs and 5169 genes which construct 124,740 and 34,298 human-mouse conserved TF and miRNA regulatory connections, respectively. The second dataset which contains 137 miRNAs, 274 TFs and 6749 genes which are compiled from the FANTOM 4 database from which the total number of human-mouse conserved regulatory connections is identified as 6631 for miRNAs and 60969 for TFs. Then, in order to reveal the significance on a statistical level, the randomization tests are applied to the connectivity matrix. Obtaining the significance of miRNA-based cFFCs lead us to conclusions about the effect of miRNAs in fine-tuning gene regulatory networks and the evolutionary role of miRNAs in the cell regulation.

Suggestions

Design of a sequence based miRNA clustering method; analysis of fungal miRNAs and host organism target genes
Narcı, Kübra; Akkaya, Mahinur S.; Oğul, Hasan; Department of Bioinformatics (2014)
MicroRNAs are small non-coding RNA molecules which contain 21-25 nucleotides, and function in post transcriptional regulation by inhibiting the translation of mRNA targets. miRNAs typically affect gene regulation by forming composite feed forward circuits (cFFCs) which also comprise a transcription factor (TF) and a target gene. By analyzing these cFFCs, the contribution of miRNAs in altering TF networks can be revealed. These contributions could either be the de-escalation of the target gene repertoire or ...
The regulatory effect of CcaR activator on the cephamycin C gene cluster of streptomyces clavuligerus
Kurt, Aslıhan; Özcengiz, Gülay; Department of Biology (2011)
Streptomyces clavuligerus produces industrially important secondary metabolites such as cephamycin C (a β-lactam antibiotic) and clavulanic acid (a potent β-lactamase inhibitor). Cephamycin C is active against penicillin-resistant bacteria due to presence of methoxyl group in C-7 position of cephalosporin nucleus. Clavulanic acid is prescribed in combination with β-lactams for treatment of various bacterial infections. Cephamycin C and clavulanic acid gene clusters form β-lactam supercluster in S. clavulige...
Functional characterization of microrna-125b expression in MCF7 breast cancer cell line
Tuna, Serkan; Erson Bensan, Ayşe Elif; Department of Biology (2010)
microRNA dependent gene expression regulation has roles in diverse processes such as differentiation, proliferation and apoptosis. Therefore, deregulated miRNA expression has functional importance for various diseases, including cancer. miR-125b is among the commonly downregulated miRNAs in breast cancer cells . Therefore we aimed to characterize the effects of miR-125b expression in MCF7 breast cancer cell line (BCCL) to better understand its roles in tumorigenesis. Here, we investigated mir-125 family mem...
Inference of Gene Regulatory Networks Via Multiple Data Sources and a Recommendation Method
Ozsoy, Makbule Gulcin; Polat, Faruk; Alhajj, Reda (2015-11-12)
Gene regulatory networks (GRNs) are composed of biological components, including genes, proteins and metabolites, and their interactions. In general, computational methods are used to infer the connections among these components. However, computational methods should take into account the general features of the GRNs, which are sparseness, scale-free topology, modularity and structure of the inferred networks. In this work, observing the common aspects between recommendation systems and GRNs, we decided to ...
Analysis of ligand-receptor cross-linked fragments by mass spectrometry
Son, Çağdaş Devrim; Hurst, GB; Naider, F; Becker, JM (Wiley, 2005-03-01)
G-protein coupled receptors (GPCRs) are a class of integral membrane receptor proteins that are characterized by a signature seven-transmembrane (7-TM) configuration. The alpha-factor receptor (Ste2p) from Saccharomyces cerevisiae is a GPCR that, upon binding of a peptide ligand, transduces a signal to initiate a cascade of events leading to the mating of haploid yeast cells. This study summarizes the application of affinity purification and of matrix-assisted laser-desorption ionization time-of-flight (MAL...
Citation Formats
B. Sürün, “Analysis of motifs in microRNA-transcription factor gene regulatory networks,” M.S. - Master of Science, Middle East Technical University, 2014.