Computational Biology of Gene Regulation

The main topic of this lecture is about how gene expression is regulated. The regulation of gene expression is of utmost importance for both unicellular organisms that need to adapt to environmental changes and nutritional stresses, and for metazoa, in which individual cells respond to extracellular signals such as hormones and growth factors by switching their activities from one state to another or changing their proliferation or differentiation status [8]. Notably, different genes have different expression patterns and the regulation of gene expression is normally accomplished at two major stages: (1) the transcription level via transcription factors/motifs (such as E2F4 transcription factor for cell-cycle regulation); (2) the translation level (also known as post-transcriptional regulation) via microRNAs (such as some microRNA inhibits the E2F1 protein, which regulates cell proliferation [9]). microRNA appears to bind to messenger RNA (mRNA) before it can be translated to proteins that switch genes on and off.