Valosin containing protein (VCP), also designated TERA (for transitional endoplasmic reticulum ATPase), is a member of the AAA family of ATPases, which are involved in a variety of cellular activities. VCP is involved in a variety of membrane functions and in the regulation of the cell cycle. VCP associates with ubiquitinated IkB-a as well as with the 26S proteosome, indicating a potential role for VCP in the proteosome-mediated degradation of IkB-a. NVL (nuclear valosin-containing protein-like), also known as NVLp, is an 856 amino acid nuclear protein belonging to the AAA ATPase family. Implicated in ATP-dependent nuclear processes and ribosome synthesis, NVL exists as three alternatively spliced isoforms designated NVL isoform 1 (NVLp.2), NVL isoform 2 (NVLp.1) and NVL isoform 3. Widely expressed, NVL is found at highest levels in pancreas, retina, heart, skeletal muscle and placenta.