Figure 5. Stabilization of PGC-1α Protein by α-MSH.
(A) Time course of induction of PGC-1α and PGC-1β mRNA (top) and PGC-1α protein (bottom) in B16-F10 cells treated with forskolin and IBMX (Fsk + IBMX) for the indicated times. (B) Stabilization of PGC-1α by α-MSH. WB, western blot.
(C) The PKA inhibitor (H89) blocks stabilization of PGC-1α protein.
(D) PGC-1α protein stabilization in cells treated with the adenylate cyclase activator (forskolin). GFP (lower panel) is expressed by the same promoter (CMV).
(E) Half-life of PGC-1α in B16-F10 cells treated with forskolin + IBMX. CHX, cycloheximide.
(F) Schematic of murine PGC-1α and predicted PKA target sites. Sites mutated to alanine in the 7A mutant are indicated below.
(G) Absence of stabilization of PGC-1α mutated at PKA target sites. The quantification of five experiments is shown below. WT, wild-type.
(H) Stabilization of PGC-1β in B16-F10 cells treated with forskolin + IBMX or α-MSH.
NS, nonspecific band. *p < 0.05. Error bars represent mean ± SD.