Fig. 5.

Acute corticosterone incubation increases glucocorticoid receptor binding at B2 SINE elements.

C6 cells were incubated with either 100 μM CORT or vehicle for 1 h prior to cross-linking. As shown above, GR localization is observed in the nucleus following corticosterone treatment (Fig. 5A). Interestingly, GR association with B2 SINE elements is higher in corticosterone treated cells compared to vehicle treated cells (Fig. 5B; mean ± SEM, student's t-test, n = 3 per group, p < 0.001) suggesting that GR activation leads to transient binding at B2 SINE loci. GR association with a known Per1 GRE is higher in corticosterone treated cells compared to vehicle treated cells (Fig. 5C, student's t-test, n = 3 per group, p < 0.05). Conversely, GR association with Myo gene did not vary between conditions (Fig. 5C). A de novo motif discovery from B2 SINE showed significant overlap with glucocorticoid response element (GRE) consensus sequence as well as GR cofactor Zbtb3 primary sequence (Fig. 5E). Similarly, motif search for the consensus GRE identified a GR-binding site within B2 SINEs (Fig. 5F).