MAPK6 is a short-lived protein with a half-life of 30 minutes in proliferating cells. Turnover is promoted by the conjugation of ubiquitin to the free amino terminal by an unknown ligase and subsequent degradation by the 26 S proteasome (Coulombe et al, 2003; Coulombe et al, 2004). Ubiquitination and degradation of MAPK6 may also occur in the nucleus as well as the cytosol.
