1. Identification of sequence elements regulating promoter activity and replication of a monopartite begomovirus-associated DNA beta satellite.
- Author
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Eini O, Behjatnia SA, Dogra S, Dry IB, Randles JW, and Rezaian MA
- Subjects
- Artificial Gene Fusion, Base Sequence, Binding Sites, Geminiviridae, Genes, Reporter, Glucuronidase biosynthesis, Glucuronidase genetics, Host-Pathogen Interactions, Molecular Sequence Data, Promoter Regions, Genetic, Protein Binding, Sequence Deletion, Nicotiana virology, Transcription, Genetic, Begomovirus physiology, DNA Replication, DNA, Satellite biosynthesis, DNA, Satellite genetics, Plant Diseases virology
- Abstract
DNA beta is a circular single-stranded satellite DNA associated with certain monopartite begomoviruses (family Geminiviridae) which causes economically important diseases such as cotton leaf curl disease. DNA beta contains a single gene, betaC1, which encodes a pathogenicity protein responsible for symptom production. Transient expression studies in Nicotiana tabacum using the beta-glucuronidase reporter gene driven by a betaC1 promoter-deletion series of the DNA beta associated with cotton leaf curl Multan virus identified a 68 nt region (between -139 and -207) which is important for betaC1 transcription. This 68 nt region contains a G-box (CACGTG) located 143 nt upstream of the betaC1 start codon. Mutation of the G-box resulted in a significant reduction in betaC1 promoter activity and DNA beta replication efficiency. In addition, the G-box motif was found to bind specifically to a protein(s) in nuclear extracts prepared from tobacco leaf tissues. Our results indicate that interaction of the G-box motif with host nuclear factors is important for efficient gene expression and replication of DNA beta.
- Published
- 2009
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