Negative effect of the 5'-untranslated leader sequence on Ac transposon promoter expression

Katia Castanho Scortecci, Ramesh Raina, Nina V. Fedoroff, Marie Anne Van Sluys

Research output: Contribution to journalArticlepeer-review

14 Scopus citations


Transposable elements are used in heterologous plant hosts to clone genes by insertional mutagenesis. The Activator (Ac) transposable element has been cloned from maize, and introduced into a variety of plants. However, differences in regulation and transposition frequency have been observed between different host plants. The cause of this variability is still unknown. To better understand the activity of the Ac element, we analyzed the Ac promoter region and its 5'-untranslated leader sequence (5' UTL). Transient assays in tobacco NT1 suspension cells showed that the Ac promoter is a weak promoter and its activity was localized by deletion analyses. The data presented here indicate that the core of the Ac promoter is contained within 153 bp fragment upstream to transcription start sites. An important inhibitory effect (80%) due to the presence of the 5' UTL was found on the expression of LUC reporter gene. Here we demonstrate that the presence of the 5' UTL in the constructs reduces the expression driven by either strong or weak promoters.

Original languageEnglish (US)
Pages (from-to)935-944
Number of pages10
JournalPlant Molecular Biology
Issue number6
StatePublished - Aug 1999
Externally publishedYes


  • 5' UTL region
  • Ac transposon
  • Inhibitory effect
  • Promoter activity
  • Transient assays

ASJC Scopus subject areas

  • Agronomy and Crop Science
  • Genetics
  • Plant Science


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