Abstract
RSG is a bZIP transcriptional activator, which regulates shoot growth by controlling GA level. Suppression of RSG resulted in severe dwarfism. We have demonstrated 1) RSG interacts with 14-3-3 proteins, which are broadly conserved regulatory factors, through phosphorylated serine-114(PS114) in RSG; 2) Binding with 14-3-3 inhibits the transport of RSG to nucleus; 3) RSG is not statically sequestered in the cytoplasm by 14-3-3, but dynamically shuttling between nucleus and cytoplasm; 4) endogenous level of GA regulates function of RSG by control of intracellular localization.
To clarify mechanism which regulate RSG nuclear export through endogenous GA level, commitment of 14-3-3 protein to the mechanism are analyzed. Because RSG interacts with 14-3-3 protein via PS114 in RSG, antibodies which specifically recognize PS114 in RSG (aPS114) are prepared. Immunoblotting using aPS114 has revealed that phosphorylation of RSG are elevated in the process of nuclear export via GA.
