Functional characterization of the HD-ZIP IV transcription factor OCL1 from maize.
J Exp Bot
; 62(1): 293-305, 2011 Jan.
Article
in En
| MEDLINE
| ID: mdl-20819789
ABSTRACT
OCL1 (OUTER CELL LAYER1) encodes a maize HD-ZIP class IV transcription factor (TF) characterized by the presence of a homeo DNA-binding domain (HD), a dimerization leucine zipper domain (ZIP), and a steroidogenic acute regulatory protein (StAR)-related lipid transfer domain (START) involved in lipid transport in animals but the function of which is still unknown in plants. By combining yeast and plant trans-activation assays, the transcriptional activation domain of OCL1 was localized to 85 amino acids in the N-terminal part of the START domain. Full-length OCL1 devoid of this activation domain is unable to trans-activate a reporter gene under the control of a minimal promoter fused to six repeats of the L1 box, a cis-element present in target genes of HD-ZIP IV TFs in Arabidopsis. In addition, ectopic expression of OCL1 leads to pleiotropic phenotypic aberrations in transgenic maize plants, the most conspicuous one being a strong delay in flowering time which is correlated with the misexpression of molecular markers for floral transition such as ZMM4 (Zea Mays MADS-box4) or DLF1 (DELAYED FLOWERING1). As suggested by the interaction in planta between OCL1 and SWI3C1, a bona fide subunit of the SWI/SNF complex, OCL1 may modulate transcriptional activity of its target genes by interaction with a chromatin remodelling complex.
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Main subject:
Plant Proteins
/
Homeodomain Proteins
/
Zea mays
/
Membrane Proteins
Language:
En
Journal:
J Exp Bot
Journal subject:
BOTANICA
Year:
2011
Type:
Article
Affiliation country:
France