The constitutive active mutant of PDK1counteracted the potentiating effect of PIK-75 on the glucose-induced secretion.

<p>(A) COS7 cells transfected with mock or PDK1(A280V) were treated with 0.5 µM PIK-75 for 30 min and subjected to immunoblotting using anti-Pi-Akt and α-tubulin antibodies. Primary cultured islets transfected with PDK1(A280V) (B; n = 6 for each group), Arf6(Q67L) (E; n = 6 for each group) and Rac1(V12) (F; n = 6 for each group) pretreated with or without 0.5 µM PIK-75 for 30 min were stimulated with 16 mM glucose. (C) Cultured islets pretreated with UCN-01 or UCN-02 for 30 min were subjected to immunoblotting using anti-Pi-Akt and Pan-Akt antibodies. (D) Cultured islets pretreated with 1.0 µM UCN-01 or UCN-02 for 30 min were stimulated with 2.2 or 16 mM glucose (n = 8 for each group). Results are represented as mean ± S.E.M. *; p<0.01, N.S.; p>0.3.