Mcl-1: Proteins and Enzymes

Mcl-1 (Myeloid Cell Leukemia 1) is a member of the Bcl-2 family of proteins. Alternative splicing results in two distinct isoforms: Mcl-1L (long) enhances cell survival by inhibiting apoptosis, while Mcl-1S (short) promotes apoptosis. The elimination of Mcl-1L is an early and required step for DNA damage-induced apoptosis. Degradation of Mcl-1L is regulated by polyubiquitination, which targets Mcl-1L to the proteasome pathway.