RT Journal Article
SR Electronic
T1 Characterization of the Molecular Mechanism Underlying Gibberellin Perception Complex Formation in Rice
JF The Plant Cell
JO Plant Cell
FD American Society of Plant Biologists
SP 2680
OP 2696
DO 10.1105/tpc.110.075549
VO 22
IS 8
A1 Hirano, Ko
A1 Asano, Kenji
A1 Tsuji, Hiroyuki
A1 Kawamura, Mayuko
A1 Mori, Hitoshi
A1 Kitano, Hidemi
A1 Ueguchi-Tanaka, Miyako
A1 Matsuoka, Makoto
YR 2010
UL http://www.plantcell.org/content/22/8/2680.abstract
AB The DELLA protein SLENDER RICE1 (SLR1) is a repressor of gibberellin (GA) signaling in rice (Oryza sativa), and most of the GA-associated responses are induced upon SLR1 degradation. It is assumed that interaction between GIBBERELLIN INSENSITIVE DWARF1 (GID1) and the N-terminal DELLA/TVHYNP motif of SLR1 triggers F-box protein GID2-mediated SLR1 degradation. We identified a semidominant dwarf mutant, Slr1-d4, which contains a mutation in the region encoding the C-terminal GRAS domain of SLR1 (SLR1G576V). The GA-dependent degradation of SLR1G576V was reduced in Slr1-d4, and compared with SLR1, SLR1G576V showed reduced interaction with GID1 and almost none with GID2 when tested in yeast cells. Surface plasmon resonance of GID1-SLR1 and GID1-SLR1G576V interactions revealed that the GRAS domain of SLR1 functions to stabilize the GID1-SLR1 interaction by reducing its dissociation rate and that the G576V substitution in SLR1 diminishes this stability. These results suggest that the stable interaction of GID1-SLR1 through the GRAS domain is essential for the recognition of SLR1 by GID2. We propose that when the DELLA/TVHYNP motif of SLR1 binds with GID1, it enables the GRAS domain of SLR1 to interact with GID1 and that the stable GID1-SLR1 complex is efficiently recognized by GID2.