Functional analysis of RF2a, a rice transcription factor.
RF2a is a bZIP transcription factor that regulates expression of the promoter of rice tungro bacilliform badnavirus. RF2a is predicted to include three domains that contribute to its function. The results of transient assays with mutants of RF2a from which one or more domains were removed demonstrated that the acidic domain was essential for the activation of gene expression, although the proline-rich and glutamine-rich domains each played a role in this function. Studies using fusion proteins of different functional domains of RF2a with the 2C7 synthetic zinc finger DNA-binding domain showed that the acidic region is a relatively strong activation domain, the function of which is dependent on the context in which the domain is placed. Data from transgenic plants further supported the conclusion that the acidic domain was important for maintaining the biological function of RF2a. RF2a and TBP (TATA-binding protein) synergistically activate transcription in vitro (Zhu, Q., Ordiz, M. I., Dabi, T., Beachy, R. N., and Lamb, C. (2002) Plant Cell 14, 795-803). In vitro and in vivo assays showed that RF2a interacts with TBP through the glutamine-rich domain but not the acidic domain. Functional analysis of such interactions indicates that the acidic domain activates transcription through mechanisms other than via the direct recruitment of TBP.
Dai
Shunhong
S
Donald Danforth Plant Science Center, St. Louis, Missouri 63132, USA.
Petruccelli
Silvana
S
Ordiz
Maria Isabel
MI
Zhang
Zhihong
Z
Chen
Shouyi
S
Beachy
Roger N
RN
D050976:Basic-Leucine Zipper Transcription Factors; D004591:Electrophoresis, Polyacrylamide Gel; D005786:Gene Expression Regulation; D017930:Genes, Reporter; D005973:Glutamine / Q000737:chemistry; D015151:Immunoblotting; D008957:Models, Genetic; D009154:Mutation; D012275:Oryza / Q000378:metabolism*; D010641:Phenotype; D010940:Plant Proteins; D030821:Plants, Genetically Modified; D010957:Plasmids / Q000378:metabolism; D011392:Proline / Q000737:chemistry; D011485:Protein Binding; D017434:Protein Structure, Tertiary; D011993:Recombinant Fusion Proteins / Q000378:metabolism; D012231:Rhizobium / Q000378:metabolism; D014026:Nicotiana / Q000235:genetics / Q000382:microbiology; D015534:Trans-Activators / Q000737:chemistry* / Q000235:genetics*; D014157:Transcription Factors / Q000737:chemistry / Q000235:genetics; D014158:Transcription, Genetic; D016335:Zinc Fingers
D050976:Basic-Leucine Zipper Transcription Factors; D010940:Plant Proteins; D011993:Recombinant Fusion Proteins; D015534:Trans-Activators; D014157:Transcription Factors; D005973:Glutamine; D011392:Proline