Fig 10.

Model for transcriptional consequences of Msx1-dependent combinatorial interactions. (A) Direct repression model: repressor Msx1 may bind a target promoter region containing the core motif TAAT via the homeodomain to exert repression. (B) Synergistic repression model: corepressor Sp3, Lhx8, or Lhx6 can interact with Msx1 to enhance repression via functional synergism. (C) Functional antagonism model: activator Dlx2, Pax9, or Snail or Lef1 via an adaptor protein can interact with Msx1 to relieve repression, leading to downstream gene activation via functional antagonism.