Autophagy is the process by which endogenous proteins and damaged organelles are destroyed intracellularly. Autophagy is postulated to be essential for cell homeostasis and cell remodeling during differentiation, metamorphosis, non-apoptotic cell death, and aging. Reduced levels of autophagy have been described in some malignant tumors, and a role for autophagy in controlling the unregulated cell growth linked to cancer has been proposed. This gene encodes a member of the autophagin protein family. The encoded protein is also designated as a member of the C-54 family of cysteine proteases. Alternate transcriptional splice variants, encoding different isoforms, have been characterized.[4]
One main function of Atg4 is to cleave the pre-protein of Atg8, leading to the non-lipidated soluble (-I) form which can be processed further by Atg3, Atg7, Atg5-12 into the lipidated form (-II) anchored to the autophagic membrane.
