Download Abstract Document Sample - graduate school of biostudies, kyoto

Functional regulation of bZIP transcription factor FD in control of flowering
*Nozomi Kawamoto1, Michiko Sasabe2, Motomu Endo1, Yasunori Machida3, and Takashi Araki1
1: Plant Developmental Biology, Graduate School of Biostudies, Kyoto University
2: Faculty of Agriculture and Life Science, Hirosaki University
3: Developmental Mechano Cell Biology, Graduate School of Science, Nagoya University
Abstract
FD, a bZIP transcription factor, preferentially expressed in the shoot apical meristem is required for FT
protein to promote flowering. FD and FT proteins interact and act as a complex at the shoot apical
meristem (SAM) to promote flowering. FD contains a possible phosphorylation sequence in its
C-terminus. Our previous studies suggest phosphorylation of 282th threonine (T282) is critical for
interaction with FT. Recent study in rice, 14-3-3s recognize phosphorylation of OsFD1 and mediate
OsFD1-Hd3a interaction.
We are interested in FD kinases which regulate FD-FT protein complex and flowering through the
phosphorylation of FD. To identify the protein kinases, we investigated biochemical properties, such
as substrate specificity and calcium requirement of kinases in the SAM extract. Our results suggest
that CDPK regulates FD-FT protein complex through the phosphorylation of FD T282. To identify the
CDPK species, we investigated its subcellular localization and kinase activity against peptide
containing T282 residue. As the results, some CDPK were localized in the nucleus and phosphorylated
T282 residue in the peptide. Results of these analyses will be presented.
Keyword: flowering, bZIP, phosphorylation, CDPK, Arabidopsis