Figure 1.

Role of Cx50-Skp2 in lens fiber differentiation. Connexin (Cx) 50 C-terminal domain (CT) interacts with S-phase kinase 2 (Skp2) in the cytosol, leading to cytoplasmic retention of Skp2 and preventing it from translocating into the nucleus. The cytosolic Skp2 is further subjected to auto-ubiquitination and proteolysis. Reduced levels of nuclear Skp2 lead to decreased ubiquitination and accumulation of p27 in the nucleus. The increased levels of p27 lead to cell cycle arrest and promotion of lens epithelial fiber cell differentiation.