Fig. 2.

Domain structure of the PGC-1s family and PGC-1α isoforms. The N-terminal region of PGC-1s is a conserved activation domain (AD). Adjacent to the N-terminal region of PGC-1α/β is a domain that represses their own activity, called the RD. The C-terminal region encompasses a well-conserved RRM, which participates in RNA alternative splicing. Moreover, the N-terminal of RRM also plays an important role in mRNA splicing, known as RS domain, which only exists in PGC-1α and PRC, but not in PGC-1β. Moreover, the existence of several promoter regions of a single PGC-1α, along with alternative splicing, leading to the production of PGC-1α isoforms. PGC-1α (also named PGC-1α1or PGC-1α-a) and NT-PGC-1α-a are transcribed by the proximal promoter of PGC-1α gene. Other PGC-1α isoforms are transcribed by a novel exon 1, located 13.7 kb upstream to of the proximal transcription start site