Figure 6.

Activation of insulin and IGF-1 signaling by KYCCSRK A) KYCCSRK enhances activation of Akt. Lysates of cells treated with KYCCSRK for 2 h, followed by insulin for 15 min, were analyzed by Western blot, which was probed sequentially with anti-Akt-phosphoS⁴⁷³ and Akt1 + Akt2 antibodies. Blots were further analyzed by densitometry. **P < 0.01. B) Activation of ERK. Cells were treated with KYCCSRK for the indicated periods. Here 40 ng/ml IGF-1 was included for the final 15 min of treatment. Western blot was probed sequentially with anti-phospho-ERK (T²⁰²Y²⁰⁴) and anti-ERK2 antibodies. C) Enhanced response of Elk1-dependent transcription by KYCCSR. Cells were transfected with an Elk1-dependent luciferase reporter system (19, 22), incubated overnight in low-glucose medium with 0.1% serum, and then treated with 20 μM KYCCSRK for 12 h (see Materials and Methods). Cell lysates were assayed for luciferase activity, normalized on that of a cotransfected β-galactosidase reporter. ***P < 0.001.