Autophagy-related protein 101  also known as ATG101 is a protein that in humans is encoded by the C12orf44 gene (chromosome 12 open reading frame 44).
Autophagy is the process of sequestering target proteins, organelles, aggregates, and other cytoplasmic species inside large membrane-bound vesicles and delivering them to lysosomes for degradation. The ATG101 protein is localized in the cytoplasm, but can possibly also be found bound to a structure known as a phagophore, involved in the initial steps of autophagy. The gene is highly conserved among mammals, as well as showing conservation among most eukaryotes. It is thought to directly interact with ATG13 in the ULK1 complex, which may be important for activating phagophores.