Yijun Qi, Ph.D
||Ph.D, Molecular Biology, Zhejiang University, Hangzhou, China
||B.Sc, Plant Pathology, Nanjing Argriculatural University, Nanjing, China
||Professor, School of Life Sciences, Tsinghua University, China
||Associate Investigator, National Institute of Biological Sciences, Beijing, China
||Assistant Investigator, National Institute of Biological Sciences, Beijing, China
||Postdoctoral fellow, Cold Spring Harbor Laboratory, USA
||Postdoctoral researcher, The Ohio State University, USA
RNA interference is a conserved mechanism of gene regulation in eukaryotes. It plays important roles in diverse biological processes including developmental regulation, antiviral defense and chromatin remodeling. In plants, there are several RNAi pathways. These include post-transcriptional gene silencing (PTGS) mediated by ~21-nt small interfering RNAs (siRNAs), microRNA (miRNA)-mediated mRNA cleavage or translational repression, and transcriptional gene silencing (TGS) that is associated with siRNA-directed chromatin remodeling including DNA and histone methylation.
We study the mechanisms of RNAi in Arabidopsis, rice, and Chlamydomonas using integrated genetic, molecular, biochemical and bioinformatic approaches. Of particular interest are how RISC complexes are formed, how small RNAs guide and reinforce the chromatin remodeling at the homologous loci, how RNAi components are specialized for distinct pathways, and the biological roles of small RNAs in Arabidopsis, rice, and Chlamydomonas development.
1. Ye, R., Wang, W., Iki, T., Liu, C., Wu, Y., Ishikawa M., Zhou, X., and Qi, Y. Cytoplasmic assembly and selective nuclear import of Arabidopsis ARGONAUTE4/siRNA complexes. Molecular Cell 46: 859-870úČ2012.
2. Wei, W., Ba, Z., Gao, M., Wu, Y., Ma, Y., Amiard, S., White, C., Danielsen, J., Yang, Y., and Qi, Y. A role for small RNAs in DNA double-strand break repair. Cell 149:101-112úČ2012.
3. Wu, L., Mao, L., and Qi, Y. Roles of DICER-LIKE and ARGPNAUTE proteins in TAS-derived small interfering RNA-triggered DNA methylation. Plant Physiology 160: 990-999úČ2012.
4. Wang, W., Ye, R., Xin, Y., Feng, X., Li, C., Zhou, X., and Qi, Y. (2011). An Importin β protein negatively regulates microRNA activity in Arabidopsis. The Plant Cell, 23: 3565-3576. (Cover story).
5. Wu, L., Zhou, H., Zhang, Q., Ni, F., Liu, C., and Qi, Y. (2010). DNA methylation mediated by a microRNA pathway. Molecular Cell, 38: 465-475 (Cover story). This work was featured in Cell, 141: 556, 2010.
6. Wu, L., Zhang, Q., Zhou, H., Ni, F., Wu, X., and Qi, Y. (2009). Rice microRNA effector complexes and targets. The Plant Cell, 21: 3421-3435.
7. Mi, S., Cai, T., Hu Y., Chen Y., Hodges E., Ni F., Wu L., Li S., Zhou H., Long C., Chen S., Hannon G., and Qi, Y. (2008) Sorting of small RNAs into Arabidopsis Argonaute complexes is directed by the 5’ terminal nucleotide. Cell, 133: 116-127. This work was featured in Cell 133:25-26, 2008.
8. Zhao, T., Li, G., Mi, S., Li, S., Hannon, G., Wang, X.-J., and Qi, Y. (2007). A complex system of small RNAs in the unicellular green alga Chlamydomonas reinhardtii. Genes and Development, 29: 1190-1203. This work was featured in: Cell 129:1029, 2007; Genes and Development 21: 1153-1156, 2007; Nature 447: 5, 2007; Nature 447: 518, 2007; Nature Review Genetics 8: 406, 2007; ACS Chemical Biology 2: 436-437, 2007 .
9. Qi, Y., He, X., Wang X-J., Kohany, O., Jurka, J. and Hannon, G. (2006) Distinct catalytic and non-catalytic roles of ARGONAUTE4 in RNA-directed DNA methylation. Nature, 443: 1008-1012.
10. Qi, Y., Denli, A. and Hannon, G. (2005). Biochemical specialization within Arabidopsis RNA silencing pathways. Molecular Cell , 19: 421-428.