Cohesin Loading onto Chromatin

Cohesin Loading onto Chromatin In mitotic telophase, as chromosomes decondense, cohesin complex associated with PDS5 (PDS5A and PDS5B) and WAPAL (WAPL) proteins is loaded onto chromatin (Shintomi and Hirano, 2009, Kueng et al. 2006, Gandhi et al. 2006, Chan et al. 2012). Cohesin loading is facilitated by the complex of NIPBL (SCC2) and MAU2 (SCC4) proteins, which constitute an evolutionarily conserved cohesin loading complex. MAU2 depletion in HeLa cells results in 2-3-fold reduction in the amount of cohesin in the chromatin fraction (Watrin et al. 2006). NIPBL mutations are the cause of the Cornelia de Lange syndrome, a dominantly inherited disorder characterized by facial malformations, limb defects, and growth and cognitive retardation (Tonkin et al. 2004). Cornelia de Lange syndrome can also be caused by mutations in cohesin subunits SMC1A (Musio et al. 2006, Borck et al. 2007, Deardorff et al. 2007, Pie et al. 2010) and SMC3 (Deardorff et al. 2007).