Molecular biology of gibberellins signaling in higher plants.
Gibberellins (GAs), a large family of tetracyclic, diterpenoid plant hormones, play an important role in regulating diverse processes throughout plant development. In recent years, significant advances have been made in the isolation of GA signaling components and GA-responsive genes. All available data have indicated that DELLA proteins are an essential negative regulator in the GA signaling pathway and GA derepresses DELLA-mediated growth suppression by inducing degradation of DELLA proteins through the ubiquitin-26S proteasome proteolytic pathway. Identification of GID1, a gene encoding an unknown protein with similarity to hormone-sensitive lipases, has revealed that GID1 acts as a functional GA receptor with a reasonable binding affinity to biologically active GAs. Furthermore, the GID1 receptor interacts with DELLA proteins in a GA-dependent manner. These results suggest that formation of a GID1-GA-DELLA protein complex targets DELLA protein into the ubiquitin-26S proteasome pathway for degradation.
Itoh
Hironori
H
National Institute of Agrobiological Sciences, Tsukuba 305-8602, Japan.
Ueguchi-Tanaka
Miyako
M
Matsuoka
Makoto
M
D017360:Arabidopsis / Q000235:genetics / Q000378:metabolism; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism; D025461:Feedback, Physiological; D017343:Genes, Plant; D005875:Gibberellins / Q000378:metabolism*; D008954:Models, Biological; D009154:Mutation; D012275:Oryza / Q000235:genetics / Q000378:metabolism; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism; D010944:Plants / Q000235:genetics / Q000378:metabolism*; D046988:Proteasome Endopeptidase Complex / Q000378:metabolism; D011956:Receptors, Cell Surface / Q000235:genetics / Q000378:metabolism; D012097:Repressor Proteins / Q000378:metabolism; D044843:SKP Cullin F-Box Protein Ligases / Q000378:metabolism; D015398:Signal Transduction; D014157:Transcription Factors / Q000378:metabolism
D029681:Arabidopsis Proteins; C512225:GID1a protein, Arabidopsis; D005875:Gibberellins; D010940:Plant Proteins; D011956:Receptors, Cell Surface; D012097:Repressor Proteins; D014157:Transcription Factors; D044843:SKP Cullin F-Box Protein Ligases; D046988:Proteasome Endopeptidase Complex; C061553:ATP dependent 26S protease