The Split Finger Protein 1 (Sfp1) is an yeast nutrient- and stress-sensitive transcription factor that controls for the expression of growth related genes involved in ribosome biogenesis, rRNA processing and translation. Sfp1 was early recognized as an unusual transcription factor that occupies the promoter of a reduced set of its target genes and its mechanism of action have been remained elusive. Sfp1 ChIP-seq experiments performed in this thesis revealed that Sfp1 may play a direct role in the regulation of RNAPII recruitment during PIC formation and this control does not necessarily require Sfp1 promoter occupancy. We have found that SFP1 positively affects the expression of growth related genes whereas it has a negative effect on stress-sensitive genes expression. Finally, we have described that Sfp1 occupies some cell cycle-dependent gene in a cell cycle dependent manner, suggesting a key role of this transcription factor in the intricate process that maintains cell size homeostasis.