Fig. 2.

Model for PGC-1α transcriptional gene expression activity. 1) PGC-1α is part of multiprotein complexes that contain histone acetyl transferase activity that open and remodels chromatin to allow the transcription factor to bind DNA. In the transcriptional initiation complex SIRT1 would maintain deacetylated PGC-1α. 2) PGC-1α and its associated proteins will move with RNA processing, elongation factors and RNA polII to transcribe the mRNA. 3) After the mRNA processing, GCN5 would acetylate PGC-1α localizing the whole complex to a RIP140 containing subnuclear repressive foci. To initiate another cycle, SIRT1 would deacetylate PGC-1α freeing it from the repressive foci, allowing it to become incorporated into protein complexes at promoter regions.