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Molecular Genetics and Genomics

, Volume 265, Issue 5, pp 763–770 | Cite as

Enhancers and core promoter elements are essential for the activity of a cryptic gene activation sequence from tobacco, tCUP

  •  K. Wu
  •  K. Malik
  •  L. Tian
  •  M. Hu
  •  T. Martin
  •  E. Foster
  •  D. Brown
  •  B. Miki
Original Paper

Abstract.

Cryptic gene regulatory elements are sequences that are inactive at their native locations in the genome but have the ability to become functional when positioned adjacent to genes. We have recently isolated such a cryptic sequence from tobacco, tCUP, that can act as a promoter. A 135-bp fragment spanning extending from position –197 to –62, relative to the transcription start site, was found to promote GUS expression in all of the major organs of transgenic Arabidopsis plants. Furthermore, this 135-bp fragment complemented the –46 minimal promoter of CaMV 35S and conferred constitutive expression on transgenic Arabidopsis plants. An electrophoretic mobility-shift assay showed that nuclear proteins prepared from tobacco leaves interact with the 135-bp fragment. tCUP has a core promoter that lacks the TATA consensus sequence but addition of a TATA-box sequence increased the core promoter activity by three-fold. The sequence surrounding the transcription start site of tCUP has sequence similarity with the initiator element (Inr), and deletion of this sequence significantly reduced promoter activity, suggesting that an essential Inr element may exist in the tCUP core promoter. Fusion of the GCC-box enhancer element from pathogenesis-related genes to the core promoter elevated tCUP core promoter activity. Our study indicates that cryptic promoters are similar in composition and organization to promoters associated with expressed genes and that their promoter elements can be combined to create composite promoters that are fully functional. This data provides direct evidence that the expression pattern of plant genes can be influenced by cryptic gene regulatory elements when they are brought into juxtaposition with genes through DNA rearrangements.

Cryptic promoter tCUP Enhancers Core promoter Transgenic plant 

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Copyright information

© Springer-Verlag 2001

Authors and Affiliations

  •  K. Wu
    • 1
  •  K. Malik
    • 1
  •  L. Tian
    • 2
  •  M. Hu
    • 1
  •  T. Martin
    • 1
  •  E. Foster
    • 1
  •  D. Brown
    • 2
  •  B. Miki
    • 1
  1. 1.Eastern Cereal and Oilseed Research Centre, Agriculture and Agri-Food Canada, Ottawa, Ontario, Canada K1A 0C6
  2. 2.Southern Crop Protection and Food Research Centre, Agriculture and Agri-Food Canada, London, Ontario, Canada N5V 4T3

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