The transcriptional activator Opaque2 recognizes two different target sequences in the 22-kD-like alpha-prolamin genes.
AUTOR(ES)
Yunes, J A
RESUMO
The maize Opaque2 (O2) protein is a "leucine zipper" DNA binding factor that interacts with the sequence TCCACGTAGA in the promoters of the 22-kD alpha-zein genes and activates its transcription. A completely different consensus sequence (GATGAPyPuTGPu) identified in b-32, a gene that encodes an abundant albumin that is also under control of the O2 locus, can also be bound by the O2 protein. We showed that the gene encoding the 22-kD-like alpha-coixin, the alpha-prolamin of the maize-related grass Coix, can also be transactivated by the O2 protein. A binding assay in vitro and footprint analysis demonstrated that the GACATGTC sequence of the alpha-coixin promoter can be recognized and protected by the maize O2 protein. Employing transient expression experiments in immature maize endosperm and tobacco mesophyll protoplasts, we demonstrated that the O2 protein can activate expression of the beta-glucuronidase reporter gene placed under the control of the 22-kD-like alpha-coixin promoter. We also demonstrated that a 22-kD-like alpha-coixin pseudogene promoter is transactivated by the maize O2 protein.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=160430Documentos Relacionados
- Opaque-2 is a transcriptional activator that recognizes a specific target site in 22-kD zein genes.
- Dominant Negative Mutants of Opaque2 Suppress Transactivation of a 22-kD Zein Promoter by Opaque2 in Maize Endosperm Cells.
- A maize zinc-finger protein binds the prolamin box in zein gene promoters and interacts with the basic leucine zipper transcriptional activator Opaque2
- The wheat transcriptional activator SPA: a seed-specific bZIP protein that recognizes the GCN4-like motif in the bifactorial endosperm box of prolamin genes.
- The Activity of the Maize Opaque2 Transcriptional Activator Is Regulated Diurnally1