Autophagy, a degradative pathway that provides recycled nutrients to cells under stress, plays both protective and deleterious roles in many diseases, including cancer, neurodegeneration, and infections. Members of the LC3 family play a key role in the maturation of the autophagosome, the central organelle of autophagy. LC3 precursors, diffusely distributed in the cytosol, are proteolytically processed to form LC3-I. Upon initiation of autophagy, the C-terminal glycine is modified by addition of a phosphatidylethanolamine (PE) to form LC3-II, which translocates rapidly to nascent autophagosomes in a punctate distribution. DNA constructs encoding fluorescent proteins fused to LC3 are widely employed for introduction into cells for monitoring autophagosome formation by fluorescence microscopy. A mutant form of LC3 with the C-terminal glycine changed to alanine (LC3-G120A) is unable to accept the PE modification and fails to translocate to the autophagosome upon induction of autophag