title: BBX32, an Arabidopsis B-Box protein, functions in light signaling by suppressing HY5-regulated gene expression and interacting with STH2/BBX21.
abstract: A B-box zinc finger protein, B-BOX32 (BBX32), was identified as playing a role in determining hypocotyl length during a large-scale functional genomics study in Arabidopsis (Arabidopsis thaliana). Further analysis revealed that seedlings overexpressing BBX32 display elongated hypocotyls in red, far-red, and blue light, along with reduced cotyledon expansion in red light. Through comparative analysis of mutant and overexpression line phenotypes, including global expression profiling and growth curve studies, we demonstrate that BBX32 acts antagonistically to ELONGATED HYPOCOTYL5 (HY5). We further show that BBX32 interacts with SALT TOLERANCE HOMOLOG2/BBX21, another B-box protein previously shown to interact with HY5. Based on these data, we propose that BBX32 functions downstream of multiple photoreceptors as a modulator of light responses. As such, BBX32 potentially has a native role in mediating gene repression to maintain dark adaptation.
authors.affiliation: Mendel Biotechnology, Inc., Hayward, California 94545, USA.
authors.forename: Hans E
authors.initials: HE
authors.lastname: Holtan
authors.forename: Simona
authors.initials: S
authors.lastname: Bandong
authors.forename: Colleen M
authors.initials: CM
authors.lastname: Marion
authors.forename: Luc
authors.initials: L
authors.lastname: Adam
authors.forename: Shiv
authors.initials: S
authors.lastname: Tiwari
authors.forename: Yu
authors.initials: Y
authors.lastname: Shen
authors.forename: Julin N
authors.initials: JN
authors.lastname: Maloof
authors.forename: Don R
authors.initials: DR
authors.lastname: Maszle
authors.forename: Masa-Aki
authors.initials: MA
authors.lastname: Ohto
authors.forename: Sasha
authors.initials: S
authors.lastname: Preuss
authors.forename: Rob
authors.initials: R
authors.lastname: Meister
authors.forename: Marie
authors.initials: M
authors.lastname: Petracek
authors.forename: Peter P
authors.initials: PP
authors.lastname: Repetti
authors.forename: T Lynne
authors.initials: TL
authors.lastname: Reuber
authors.forename: Oliver J
authors.initials: OJ
authors.lastname: Ratcliffe
authors.forename: Rajnish
authors.initials: R
authors.lastname: Khanna
mesh_terms: D017360:Arabidopsis / Q000235:genetics* / Q000528:radiation effects; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism*; D050976:Basic-Leucine Zipper Transcription Factors / Q000378:metabolism*; D002352:Carrier Proteins / Q000235:genetics / Q000378:metabolism*; D003624:Darkness; D020869:Gene Expression Profiling; D018506:Gene Expression Regulation, Plant / Q000528:radiation effects*; D017343:Genes, Plant / Q000235:genetics; D018546:Hypocotyl / Q000254:growth & development / Q000528:radiation effects; D008027:Light; D055537:Light Signal Transduction / Q000235:genetics / Q000528:radiation effects*; D008954:Models, Biological; D009687:Nuclear Proteins / Q000378:metabolism*; D011485:Protein Binding / Q000528:radiation effects; D014157:Transcription Factors / Q000378:metabolism*
chemical_list: D029681:Arabidopsis Proteins; C556245:BBX21 protein, Arabidopsis; C568263:BBX32 protein, Arabidopsis; D050976:Basic-Leucine Zipper Transcription Factors; D002352:Carrier Proteins; C109254:HY5 protein, Arabidopsis; D009687:Nuclear Proteins; D014157:Transcription Factors