SKI family transcriptional corepressors (including SKI and SnoN) (SKI (SKI proto-oncogene) and SnoN (SKI-like protein, also known as SKIL))

The "SNON/SKI axis" refers to the group of related transcriptional corepressors SKI and SnoN (also known as SKIL), which act as principal negative regulators of transforming growth factor beta (TGF-β) signaling. These proteins do not directly bind DNA but instead exert their effect by interacting with key Smad proteins within the TGF-β pathway. By forming protein complexes with receptor-activated Smads (Smad2/3) and co-Smad (Smad4), SKI and SnoN displace active complexes and inhibit TGF-β-driven gene transcription[1][2]. They achieve transcriptional repression by preventing the assembly of active Smad complexes at the promoters of TGF-β target genes, stabilizing inactive Smad complexes, and recruiting transcriptional corepressors such as N-CoR[1]. SKI and SnoN can be degraded via ubiquitin-mediated pathways involving E3 ubiquitin ligases such as RNF111, thus relieving repression of TGF-β signaling[3]. Both SKI and SnoN possess oncogenic potential when overexpressed, contributing to cell transformation, tumorigenesis, and the regulation of cell fate decisions. The "SNON/SKI axis" is not a single molecular entity but describes a regulatory node in cell signaling, with implications for cancer, fibrosis, and immune modulation[2][4]. Direct pharmacological targeting of these proteins is not established clinically, but gene therapies and indirect approaches that modulate their activity are under investigation[4].

Other names

SKISnoNSKI-like protein (SKIL)c-SkiSKIL

Drugs or interventions that modulate the SKI/SnoN axis may promote or inhibit the degradation or activity of SKI/SnoN proteins, thereby affecting TGF-β signaling[2][4]