The Arabidopsis PEAPOD2 transcription factor interacts with geminivirus AL2 protein and the coat protein promoter.
The TrAP protein of bipartite begomoviruses activates the coat protein (CP) promoter in mesophyll and derepresses the promoter in vascular tissue through two sequences, located 60-125 bp and 1.2-1.5 kbp respectively, upstream of the CP gene. TrAP does not, however, exhibit specific binding to either sequence directly. We have identified a plant-specific DNA-binding protein, Arabidopsis PEAPOD2 (PPD2), that specifically binds sequences mediating activation of the CP promoter of Tomato golden mosaic virus (TGMV) and Cabbage leaf curl virus in mesophyll. This protein does not however, bind sequences required for TrAP-mediated derepression in phloem. TGMV TrAP interacts with the PPD2/CP promoter complex in electrophoretic mobility shift assays. PPD2 is associated with the nucleus, as expected for a transcription factor, but is not capable of activating transcription directly. Thus, geminivirus TrAP is likely targeted to the CP promoter through interaction with PPD2, leading to activation of CP gene expression.
Lacatus
Gabriela
G
Greheey Children's Cancer Research Institute, The University of Texas Health Sciences Center, San Antonio, San Antonio, TX 78229, USA.
Sunter
Garry
G
D017360:Arabidopsis / Q000235:genetics / Q000378:metabolism / Q000821:virology; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism*; D053839:Begomovirus / Q000378:metabolism; D036022:Capsid Proteins / Q000378:metabolism*; D018076:DNA, Complementary / Q000235:genetics; D024202:Electrophoretic Mobility Shift Assay; D015967:Gene Expression Regulation, Viral; D011401:Promoter Regions, Genetic; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism*; D014764:Viral Proteins / Q000378:metabolism*
C483731:AL2 protein, Begomovirus; D029681:Arabidopsis Proteins; D036022:Capsid Proteins; D018076:DNA, Complementary; C000593019:TIFY4B protein, Arabidopsis; D014157:Transcription Factors; D014764:Viral Proteins