Synergy of importin α recognition and DNA binding by the yeast transcriptional activator GAL4

Chee Kai Chan, David A. Jans

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21 Citations (Scopus)


The N-terminus of the yeast transcriptional activator GAL4 contains partially overlapping nuclear targeting and DNA binding functions. We have previously shown that GAL4 is recognised with high affinity by importin β and not by the conventional nuclear localisation sequence binding importin α subunit of the importin α/β heterodimer. The present study uses ELISA-based binding and electrophoretic mobility shift assays to show that recognition of GAL4 by importin α can occur, but only when GAL4 is bound to its specific DNA recognition sequence. Intriguingly, binding by importin α enhances DNA binding on the part of GAL4, implying a synergistic co-operation between these two functions. The results implicate a possible role for importin α in the nucleus additional to its established role in nuclear transport, as well as having implications for the use of GAL4 as a DNA carrier in gene therapy applications.

Original languageEnglish
Pages (from-to)221-224
Number of pages4
JournalFEBS Letters
Issue number1-2
Publication statusPublished - 26 Nov 1999
Externally publishedYes


  • DNA binding protein
  • GAL4
  • Importin
  • Nuclear targeting signal
  • Transcription factor

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