Glycogen, a branched polymer of glucose, acts as an intracellular carbon and 
energy reserve in many tissues and cell types. An important pathway for its 
degradation is by transport to lysosomes in an autophagy-like process. It has 
been proposed that starch-binding domain-containing protein 1 (Stbd1) may 
participate in this mechanism by anchoring glycogen to intracellular membranes. 
In addition, Stbd1 has been reported to interact with a known autophagy protein, 
GABARAPL1, a member of the Atg8 family. Here, we confirm this interaction and 
identify an Atg8 interacting motif (AIM) in Stbd1 necessary for GABARAPL1 
binding as judged by co-immunoprecipitation from cell extracts and 
co-localization in cells as evidenced by immunofluorescence microscopy. The AIM 
sequence of Stbd1 (200)HEEWEMV(206) lies within a predicted disordered region of 
the molecule and fits the consensus of other AIM sequences in cargo-specifying 
proteins such as p62 and Nix. Mutation of the AIM, including single point 
mutations of either W203 or V206, eliminated the co-localization of Stbd1 with 
both over-expressed and endogenous GABARAPL1. Stbd1 may therefore function as a 
novel cargo binding protein that delivers glycogen to lysosomes in an autophagic 
pathway that could be termed "glycophagy".