LC3 Interacting Regions (LIRs), also known as ATG8-interacting motifs (AIMs), are short-linear motifs (SLiMs) of autophagy receptors and adaptor proteins that facilitates the selective recruitment of autophagy substrates to the autophagosome. ATG8 proteins are highly conserved in eukaryotes and play a key role in selective autophagy as they recognise and bind different autophagy receptors and adaptors containing a specific class of SLiMs. LIRs are characterised by degenerated sequences with a four-residue core central sequence involved in ATG8-binding, with the W/Y/FxxL/I/V pattern. Based on the aromatic amino acid in position 1 they can be classified into W-type, Y-type and F-type. This entry is the F-type LIR motif from ATG4, which contains the seqeunce FEI/VL. There are acidic residues at the N-terminal of this motif (Asp and Glu), which may contribute to stabilize the binding or may provide specificity toward a certain class of ATG8 proteins [1].

1: Structure and Dynamics in the ATG8 Family From Experimental to Computational Techniques. Sora V, Kumar M, Maiani E, Lambrughi M, Tiberti M, Papaleo E; Front Cell Dev Biol. 2020;8:420. PMID:32587856