Figure 6. Model for epigenetic potentiation of Gal4 activation through interdomain potentiation.
A. In wild-type cells during early activation, Gal80 repression is relieved in subset of population, leading to lower-level expression. Inter-domain interaction between central domain and activation domain potentiates higher activation levels in cells relieved of Gal80. B. During memory (or in the presence of basal Gal1 expression), Gal80 repression is relieved early in whole population leading to unimodal, fully potentiated GAL gene expression. C. gal4Δcd cells show uniform, low-level activation.