VCP not only causes many kinds of disease, it performs many cellular tasks. “It has probably close to a dozen defined cellular activities, and that likely is just the tip of the iceberg,” Taylor said. The protein participates in transcription, cell division, Golgi assembly, and autophagy, to name a few, but even so, “it is basically a one-trick pony,” Taylor said. Wherever it is, VCP’s job is to untangle ubiquitinated proteins from multi-component complexes so the tagged protein can be destroyed by the proteasome. For example, in the endoplasmic reticulum, if one protein in a complex is misfolded, VCP helps to retrieve and degrade it.
https://www.alzforum.org/news/research-news/adding-als-manifestations-vcp-mutations