Figure 7. The Nur77 important region A (NIR-A) and NIR-C regions of the Nur77 promoter contribute to the calmodulin kinase I (CaMKI)-dependent activation. (A) MA-10 Leydig cells were cotransfected with either an empty expression vector (open bars) or expression vectors for wild-type CaMKI (CaMKI WT; hatched bars) or constitutively active CaMKI (CaMKI CA; solid bars) along with a –1013-bp or –331-bp Nur77 reporter constructs. (B) MA-10 cells were cotransfected with an empty expression vector (open bars) or an expression vector encoding CaMKI CA along with Nur77 reporter constructs composed of different combinations of the NIR-A, NIR-B, and NIR-C regions, as indicated on the left of the graph. The number of experiments, each performed in duplicate, is indicated. Results are shown as fold activation over control (±SEM). All activations by CaMKI WT or CA are statistically significant (P < .01).