The ETS-Domain Transcription Factor Elk-1 Regulates COX-2 Gene Expression and Inhibits Glucose-Stimulated Insulin Secretion in the Pancreatic β-Cell Line INS-1
Figure 3
Identification of Elk-1 binding site in COX-2 promoter by electrophoretic mobility shift assay (EMSA). (a) Wild-type probe 1 (−87/−64 of COX-2 promoter) was incubated without (lane 1) or with (lane 2) INS-1 nuclear proteins. Wild-type probe 2 (−1300/−1277) (lane 3) or wild-type probe 3 (−1824/−1801) (lane 4) was incubated with INS-1 nuclear proteins. (b) Wild-type probe 1 was incubated without (lane 1) or with (lane 2) INS-1 nuclear proteins in the absence or presence of unlabelled probe 1 (lanes 3–6). Lanes 3 and 4 contain the wild-type probe 1, and lanes 5 and 6 contain the mutant probe 1, each at 50- and 100-fold molar excess, respectively. In lane 7, wild-type probe 1 was incubated with INS-1 nuclear proteins in the presence of Elk-1 antibody.
