γ-Aminobutyric Acid Receptor-associated Protein (GABARAP), also known as Apg8p1, is 117 amino acid (aa) protein with a predicted molecular weight of 14 kDa. It is a member of the GABARAP subfamily of the autophagy-related 8 (Atg8) family of proteins. The GABARAP subfamily also includes GABARAPL1. GABARAP has 100% aa sequence identity with its mouse and rat orthologs and is orthologous to yeast Atg8. Atg8 family members show structural similarity with ubiquitin, but lack aa sequence similarity. GABARAP was first described for its putative involvement GABA A Receptor trafficking. However, it is best known for its role in autophagy. GABARAP covalently attaches to phosphatidylethanolamine (PE) in the phagophore (autophagosome precursor) membrane using a ubiquitin-like conjugation system that includes ubiquitin-activating (E1)-, ubiquitin-conjugating (E2)-, and ubiquitin ligase (E3)-like enzymes. Here it is involved in the later stages of autophagosome maturation. It may also be involved in cargo recruitment to autophagosomes.