Predicted to enable acetylcholine receptor binding activity. Predicted to be involved in protein retention in ER lumen and retrograde vesicle-mediated transport, Golgi to endoplasmic reticulum. Predicted to act upstream of or within positive regulation of protein localization to plasma membrane and skeletal muscle acetylcholine-gated channel clustering. Predicted to be located in Golgi apparatus; cell surface; and endoplasmic reticulum-Golgi intermediate compartment. Predicted to be integral component of Golgi membrane. Orthologous to human RER1 (retention in endoplasmic reticulum sorting receptor 1). [provided by Alliance of Genome Resources, Apr 2022]