Mutation of the Akt consensus phosphorylation site in p300 does not alter the cooperativity between ngn3, p300, and Akt. P19 cells were transfected with expression vectors for Gal4-p300 or Gal4-p300 S1834A, ngn3, constitutively active (C/A) Akt1 or vector control, and the pFR Gal4-responsive luciferase reporter.