The studies of AtYak1, a novel DYRK family member in Arabidopsis thaliana

• Main Authors: Yi-Chen Wu, 吳怡蓁
• Other Authors: Shu-Hsing Wu
• Format: Others
• Language: zh-TW
• Published: 2004
• Online Access: http://ndltd.ncl.edu.tw/handle/13668171184438846376

碩士 === 國立中央大學 === 生命科學研究所 === 92 === Light provides an important environmental cue regulating plant growth and development. Light perception is mediated by the action of several photoreceptors. The signal transduction and light responses in higher plants involve the regulation of differential gene expression. Considerable amount of efforts have been put in the studies of light-mediated signaling pathway in plants. DNA microarray technology serves as a powerful approach in addition to the biochemical and genetic methods in identifying novel molecular components in light signaling pathway. After analyzing microarray, we choose a gene encoding WD-containing protein, termed LWD1, which is clearly up-regulated in response to light treatment and is dramatically down-regulated in dark-treated Arabidopsis leaves. Similar to other WD-containing proteins, LWD1 could function in interacting or coordinating multiple protein partners responsible for proper signal transduction. Via yeast two-hybrid, preliminary data reveal strong protein-protein interaction between LWD1 and AtYak1. AtYak1 is the first DYRK（dual specificity Yak1-related protein kinase）family member identified in plants and exists as a single copy gene in Arabidopsis. In this thesis, I will report the initial efforts in characterizing the biological properties and functions of AtYak1. Results suggest that AtYak1 is a putative transcriptional activator. Subcellular localization of AtYak1 is analyzed by generating a AtYak1-GFP translational fusion protein for protoplast transient assay. AtYak1-GFP is observed both in the cytoplasm and in the nucleus. Real time RT-PCR was employed to study the expression pattern of AtYAK1 in various tissues of Arabidopsis, including rosette leaves, flowers, silique, and roots. Results show that AtYak1 is expressed ubiquitously but predominantly in roots. Furthermore, to gain more insights on the biological functions of AtYak1, we obtained AtYak1 T-DNA insertion lines and transgenic Arabidopsis overexpressing AtYak1. Phenotype comparison between wild type and AtYak1 mutant Arabidopsis indicate that AtYak1 may involve in leaf differentiation and development.