Identification of a nucleotidyltransferase gene in miRNA tailing and degradation in Arabidopsis

Zhao, Yuanyuan

Date: Saturday, January 14, 2012
Time: 5:10 PM

Room: San Diego

Yuanyuan Zhao , Department of Botany and Plant Sciences, Institute of Integrative Genome Biology, University of California Riverside, Riverside, CA

Yu Yu , College of life sciences, Shenzhen University, Shenzhen, China

Jixian Zhai , Department of Plant and Soil Sciences and Delaware Biotechnology Institute, University of Delaware, Newark, DE

Vanitharani Ramachandran , Department of Botany and Plant Sciences, Institute of Integrative Genome Biology, University of California Riverside, Riverside, CA

Thanh Theresa Dinh , ChemGen IGERT program, Center for Plant Cell Biology, Institute of Integrative Genome Biology, University of California Riverside, Riverside, CA

Blake C. Meyers , Department of Plant and Soil Sciences and Delaware Biotechnology Institute, University of Delaware, Newark, DE

Beixin Mo , College of life sciences, Shenzhen University, Shenzhen, China

Xuemei Chen , Department of Botany and Plant Sciences, Institute of Integrative Genome Biology, University of California Riverside, Riverside, CA

MiRNAs are a class of small RNA molecules that post-transcriptionally regulate their target mRNAs in eukaryotes. In Arabidopsis, miRNAs are protected from degradation by a 2'-O-methyl group introduced by HEN1 at their 3' terminal nucleotide. In hen1 mutants, miRNAs have decreased abundance and undergo 3' truncation and tailing. In this study, we have identified a TRF4-like nucleotidyltransferase protein NTP4 (Nucleotidyltransferase Protein 4) in Arabidopsis that functions in the tailing of miRNAs without 2'-O-methylation in a hen1 mutant. A mutation in NTP4 suppresses the morphological phenotypes of a hen1 single mutant. The hen1 ntp4 double mutant shows increased miRNA abundance and decreased tailing levels compared with the hen1 single mutant. In vitro assays show that NTP4 is capable of adding nucleotides to unmethylated miRNA oligos, and its activity is blocked by 2'-O-methylation at the 3' terminal nucleotide of miRNA oligos. Our results suggest that NTP4 functions in the tailing of miRNAs without 2'-O-methylation and promotes their degradation in Arabidopsis.

W640 Identification of a nucleotidyltransferase gene in miRNA tailing and degradation in Arabidopsis