The BCL-2 family proteins regulate mitochondrial apoptosis. BCL-rambo is a poorly characterised BCL-2 family protein with conflicting roles in apoptosis and a proposed role in autophagy. BCL-rambo possess a unique unstructured BHNo domain, that contains an LC3-interacting region (LIR) motif. LIR motifs are present in autophagy receptor and adaptor proteins, and they are recognised by ATG8 family proteins, the core effectors in autophagy and mitophagy. We identified two serine residues located at the -1 and -6 positions of the core LIR. In the absence of phosphorylation BCL-rambo LIR peptides failed to bind the ATG8 proteins. Phosphorylation of either one of the two serine residues enabled binding to select ATG8 family proteins, with phosphorylation of both serines increasing affinity and enabling binding to all six ATG8 family proteins, preferentially to GABARAPL1, GABARAPL2 and LC3C. Crystal structures of the double-phosphorylated peptide bound to GABARAPL1 and GABARAPL2 were solved. The crystal structures showed an important role for phosphorylation at the LIR -1 position as that phosphoserine formed a salt-bridge. However, the role of phosphorylation at -6 is less apparent, leaving unanswered questions about its role in binding ATG8 proteins and autophagy.