Japanese

Research

How is expression of miRNAs controlled?

We have witnessed a paradigm shift in research of gene regulation, and the importance of post-transcriptional regulation of protein-coding genes has now been broadly recognized. Expression of miRNAs should also be regulated at multiple levels (Fig 1). Precise regulation of miRNA levels is important because misregulation of miRNAs often results in human disease. We study how miRNA levels are controlled under healthy and disease conditions using genomics and biochemical techniques, and examine their biological significance at the cellular and organismal levels (Fig 2).


fig.1 microRNA processing pathway.

Why are there many ways to produce miRNAs?

We discovered novel mechanisms of miRNA processing that use machineries known to produce other RNA families, such as mRNA introns and ribosomal RNAs (Fig 1). This means that RNA processing machineries often have unexpected roles in gene regulation. We study the biological significance of non-canonical roles of various RNA processing pathways.


fig.2 Outline of research strategies.

How have small RNA pathways changed in evolution?

Our previous studies revealed a variety of small RNA pathways including those that are only present in particular organisms functioning as natural defense systems (Fig 1). To capture the full diversity of animal small RNA pathways, we are sequencing small RNAs from various animals by next generation sequencing. Discoveries of new small RNA pathways may pave the way for the development of novel technologies that complement the current CRISPR or RNA interference technologies.

selected publication

  1. Zhou and Lim et al., eLife, 7:e38389, 2018
  2. Goh and Okamura, Methods Mol Biol., 1680, 41-63, 2018
  3. Lim and Ng et al., Cell Reports, 15, 1795-1808, 2016
  4. Chak et al., RNA, 21, 375-384, 2015
  5. Pek and Okamura, WIREs RNA, 6, 671-686, 2015
  6. Chak and Okamura, Frontiers in Genetics, 5, 172, 2014
  7. Okamura et al., Genes & Dev, 27, 778-792, 2013
  8. Okamura et al., Molecular Cell., 36, 431-444, 2009
  9. Okamura et al., Nature, 453, 803-806, 2008
  10. Okamura et al., Cell, 130, 89-100, 2007