. "Transcriptional coactivator for creb1 which activates transcription through both consensus and variant cAMP response element (CRE) sites. Acts as a coactivator, in the SIK/TORC signaling pathway, being active when dephosphorylated and acts independently of creb1 'Ser-119' phosphorylation. Enhances the interaction of creb1 with taf4. Regulates the expression of specific CREB-activated genes such as the steroidogenic gene, StAR. Potent coactivator of ppargc1a and inducer of mitochondrial biogenesis in muscle cells (By similarity)." .