Chapter 12 - Transcription Activators in Eukaryotes

Question 1

How was it shown that the DNA and activation domains act independently?

Answer 1

A chimeric activator was made by inserting a prokaryotic LexA DNA domain and a eukaryotic GAL4 activation domain into a plasmid and inserting that plasmid into yeast. Another plasmid was inserted into the yeast with the DNA region for LexA in one spot and the gene for GAL4, followed by a reporter gene, in another segment.

In the positive control, not changes were made and the yeast produced beta-galactosidase from GAL4 normally.

In the next scenario the GAL4 upstream activator sequence was removed and no beta-galactosidase was made.

In the experimental plasmid there was some downstream gene expressio, about a third of WT.