Identification of a minimal sequence required for activation of the tomato golden mosaic virus coat protein promoter in protoplasts

Virology. 2003 Jan 20;305(2):452-62. doi: 10.1006/viro.2002.1757.

Abstract

Transient expression studies using a Nicotiana benthamiana suspension cell-derived protoplast system have identified a minimal sequence that is necessary and sufficient for activation of the tomato golden mosaic virus coat protein (CP) promoter by the viral TrAP protein (also called AL2). The sequence has a bipartite arrangement in which elements located between -125 to -107 and -96 to -60 from the transcription start site are both required for TrAP-mediated activation. One of the sequences (-96 to -60) also appears to interact with a repressor, as its deletion increases basal promoter activity in the absence of TrAP. That competition experiments using the -107 to -60 sequence to titrate the repressor also resulted in increased basal transcription is consistent with this idea. Thus, in a protoplast system which models mesophyll, regulation of the minimal CP promoter involves both activation and derepression by TrAP.

Publication types

  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Capsid Proteins / genetics*
  • Cell Line
  • Geminiviridae / genetics*
  • Gene Expression Regulation, Viral*
  • Lycopersicon esculentum / virology*
  • Promoter Regions, Genetic*
  • Protoplasts / virology*
  • Repressor Proteins / physiology
  • Trans-Activators / physiology

Substances

  • Capsid Proteins
  • Repressor Proteins
  • Trans-Activators