Common Logic of Transcription Factor and microRNA Action

Trends Biochem Sci. 2004 Sep;29(9):462-8. doi: 10.1016/j.tibs.2004.07.001.


Over the past few years, microRNAs (miRNAs) have emerged as abundant regulators of gene expression. Like many transcription factors (TFs), miRNAs are important determinants of cellular fate specification. Here I provide a conceptual framework for miRNA action in the context of creating cellular diversity in a developing organism, and emphasize the conceptual similarity of TF- and miRNA-mediated control of gene expression. Both TFs and miRNAs are trans-acting factors that exert their activity through composite cis-regulatory elements that are 'hard-wired' into DNA or RNA. TFs and miRNAs act in a largely combinatorial manner - that is, many different TFs or miRNAs control one gene - and they act cooperatively on their targets - that is, there are several cis-regulatory elements for a single TF or miRNA species in a target gene. Just as the set of TFs in a given cell type has been proposed to constitute a 'code' that specifies cellular differentiation, so 'miRNA codes' are likely to have conceptually similar roles in the specification of cell types.

Publication types

  • Review

MeSH terms

  • Animals
  • Combinatorial Chemistry Techniques
  • DNA / genetics
  • Gene Expression Regulation
  • MicroRNAs / genetics*
  • Models, Genetic
  • RNA / genetics
  • Transcription Factors / metabolism*


  • MicroRNAs
  • Transcription Factors
  • RNA
  • DNA