A multiple-stimuli-responsive as-1-related element of parA gene confers responsiveness to cadmium but not to copper.
AUTOR(ES)
Kusaba, M
RESUMO
The expression of parA, an auxin-regulated gene expressed during the culture of tobacco (Nicotiana tabacum L.) mesophyll protoplasts, is induced by cadmium. To identify the cadmium-responsive element, we examined the parA promoter using the GUS reporter gene. Cadmium responsiveness was retained in a 5' deletion of the parA promoter to -78 bp, but it was nullified by further deletion to -49bp, which implies that the region -49 to -78 bp contained a cadmium-responsive element. This region contains a sequence similar to as-1, an enhancer sequence from the cauliflower mosaic virus 35S RNA promoter that binds the nuclear factor ASF-1. We named the sequence in the parA promoter pas. Gel-shift assays revealed that pas and as-1 compete for the same DNA-binding nuclear protein(s). Since pentamers of either pas and as-1 were able to confer cadmium responsiveness on a minimal promoter but mutant as-1 was not, we propose that pas and as-1 are involved in cadmium-responsive gene expression. Neither pas nor as-1 conferred responsiveness to copper. The specificity of this response, involving the function of as-1-related elements including pas, is discussed.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=160992Documentos Relacionados
- Mammalian metal response element-binding transcription factor-1 functions as a zinc sensor in yeast, but not as a sensor of cadmium or oxidative stress
- Monocyte Responsiveness to Chemotactic Stimuli is a Property of a Subpopulation of Cells that can Respond to Multiple Chemoattractants
- A GC-rich element confers epidermal growth factor responsiveness to transcription from the gastrin promoter.
- Identification of a protein that confers calcitonin gene-related peptide responsiveness to oocytes by using a cystic fibrosis transmembrane conductance regulator assay.
- Multiple copies of a G-rich element upstream of a cAMP-inducible Dictyostelium gene are necessary but not sufficient for efficient gene expression.
