c - / ! os Ab 
+ 
FIGURE 13. 
- + - 
+ c-fos — ► 
Ab 
AP-1 
I II l 
Control 1 Hour 
Gel mobility shift analysis of AP- 1 complex formation. In 
addition to stimulation of c-fos mRNA and Fos and Fra proteins, 
treatment with cocaine also increases the capacity for formation 
of a Fos-containing protein DNA complex. A double-stranded 
oligonucleotide from the GALV enhancer containing the AP-1 
consensus was incubated with striatal nuclear extracts from 
control and cocaine-treated rats. The location of the basal 
AP-1 complex is indicated. The entire complex can be shifted 
further still by concurrent incubation with the Fos antibody (Ab), 
which makes the complex larger and thus less mobile. The 
super-shift indicates that Fos-immunoreactive proteins are in 
the basal state AP-1 complex and are elevated after cocaine 
induction. Higher concentrations of antibody disrupt the 
complex completely via sequestration of Fos proteins; complex 
formation could also be competed by an excess of unlabeled 
AP-1 oligonucleotide but was unaffected by an excess of 
unrelated oligonucleotide (not shown). 
200 
