FIGURE 1.

6-OHDA activates the JNK pathway in SHSY5Y cells and induces JNK translocation to the mitochondria. A, SHSY5Y cells were treated with 25 μm 6-OHDA for 4 h, and JNK signaling was evaluated by Western blot analysis. Proteins (30 μg) were resolved by SDS-PAGE, and antibodies for phospho-MKK4, MKK4, phospho-JNK, and JNK were used to detect proteins of interest in whole cell lysates. α-Tubulin was used as a loading control. B, mitochondrial isolations were prepared from SHSY5Y cells stressed with 25 μm 6-OHDA for 4 h. The mitochondria were monitored by Western analysis for JNK, phospho-JNK, MKK4, phospho-MKK4, MKK7, and phospho-MKK7. COX-IV served as the mitochondrial loading control. Enolase, histone H3, and calnexin blots are presented to demonstrate purity of mitochondrial preparations. IB, immunoblot.