Kinase-mediated regulation of common transcription factors accounts for the bone-protective effects of sex steroids
J. Clin. Invest. Stavroula Kousteni, et al. 111:1651 doi:10.1172/JCI17261 [Go to this article.]

Figure 3
Estrogens induce activation of ERK-regulated transcription factors in vitro. GAL4-DBD depicts the DNA binding domain of the galactosidase gene 4, ElkC depicts the carboxy terminus of the Elk-1 molecule, P and p indicate phosphorylation. HeLa cells were cotransfected with empty vector (EV) or ERα and either WT GAL4-DBD-ElkC (ElkC) or the mutant GAL-ElkC383/389 (ElkC383/389) constructs. ElkC activity was measured by cotransfection of a reporter plasmid in which luciferase (luc) transcription is under the control of the GAL4-binding site (GAL4–binding site–luc) (a). HeLa cells were transfected with ERα and the SRE-SEAP, together with ElkC, dn Elk-1, or ElkC383/389 constructs (b). OB-6 murine osteoblastic cells were treated with E₂ for the indicated periods of time, and the phosphorylation of Elk-1, C/EBPβ, and CREB was determined with Western blot analysis (c and d). In c and d, numbers on the y axis indicate ratios.