ECM29 is a 1,845 amino acid protein containing twenty-seven HEAT repeats. Localizing primarily to endoplasmic reticulum, ECM29 acts as an adapter or scaffolding protein, binding to the 26S proteasome, motor proteins, and other compartment specific proteins. The N-terminus of ECM29 binds endocytic proteins, including rabaptin, Rab11-FIP4, and VPS11, while the C-terminus binds myosins and kinesins. ECM29 may also play a role in endoplasmic reticulum (ER)-associated protein degradation (ERAD) in addition to other enhanced proteolysis.