Weiqiang Qian
Email: wqqian(at)pku(dot)edu(dot)cn；
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DNA methylation is an important epigenetic marker for the establishment and maintenance of gene expression pattern across cellular division and plays critical roles in transposon silencing, chromosome stability and gene expression. DNA methylation pattern is coordinately controlled by methylation and demethylation reactions. In Arabidopsis, DRM2, MET1 and CMT3 are principle enzymes involved in DNA methylation and RNA-directed DNA methylation (RdDM) pathways were well characterized. In plants, active DNA demethylation is catalyzed by a subfamily of bi-functional DNA glycosylases represented by ROS1 and DME. These DNA demethylases directly excise the 5-methylcytosine base and then cleave the DNA backbone at the abasic site. The resultant single-nucleotide gap is subsequently filled with an unmodified cytosine through the DNA base excision repair pathway. In contrast to the establishment of DNA methylation, little is known about the locus-specific guidance for active DNA demethylation. We will focus on the mechanism and regulation of active DNA demethylation pathway in plants.
Selected Publications:
1. Qian W*, Miki D*, Zhang H, Liu Y, Zhang X, Tang K, Kan Y, La H, Li X, Li S, Zhu X, Shi X, Zhang K, Pontes O, Chen X, Liu R, Gong Z and Zhu JK. A Histone Acetyltransferase Regulates Active DNA Demethylation in Arabidopsis. Science. 2012 Jun 15;336(6087):1445-8.
2. Li X, Qian W, Zhao Y, Wang C, Shen J, Zhu J-K and Gong Z. The anti-Silencing role of the RNA-directed DNA methylation pathway and a histone acetyltransferase in Arabidopsis. Proc Natl Acad Sci U S A. 2012 Jul 10;109(28):11425-30.
3. Martínez-Macías M*, Qian W*, Miki D*, Pontes O, Liu Y, Tang K, Liu R, Morales-Ruiz T, R. Ariza R, Roldán-Arjona R, and Zhu JK. A DNA 3’-phosphatase functions in active DNA demethylation in Arabidopsis. Mol Cell. 2012 Feb10; 45(3): 357-70. (*Contributed equally to this work)
4. Mang HG*, Qian W*, Zhu Y, Qian J, Kang HG, F.Klessig D and Hua J. ABA deficiency antagonizes high temperature inhibition of disease resistance through enhancing nuclear accumulation of resistance proteins SNC1 and RPS4 in Arabidopsis. Plant Cell. 2012 Mar; 24 (3): 1271-84. (*Contributed equally to this work)
5. Wang L*, Li Z*, Qian W, Guo W, Gao X, Huang L, Wang H, Zhu H, Wu JW, Wang D and Liu D. Arabidopsis purple acid phosphatase AtPAP10 is predominantly associated with the root surface and play an important role in plant tolerance to phosphate limitation. Plant Physiol. 2011 Nov; 157 (3): 1283-99.
6. Tran HT, Qian W, Hurley BA, She YM, Wang D, and Plaxton WC. Biochemical and molecular characterization of AtPAP12 and AtPAP26: the predominant purple acid phosphatase isozymes secreted by phosphate-starved Arabidopsis thaliana. Plant Cell Environ. 2010 Nov;33 (11): 1789-803
7. Gao Z, Liu HL, Daxinger L, Pontes O, He X, Qian W, Lin H, Xie M, Lorkovic ZJ, Zhang S, Miki D, Zhan X, Pontier D, Lagrange T, Jin H, Matzke AJ, Matzke M, Pikaard CS and Zhu JK. An RNA polymerase II- and AGO4-associated protein acts in RNA-directed DNA methylation. Nature. 2010 May 6;465(7294):106-9.
8. Zhu Y, Qian W, and Hua J. Temperature modulates plant defense responses through NB-LRR proteins. PLoS Pathog. 2010 Apr 1;6 (4):e1000844