Quantitative interaction mapping reveals an extended UBX domain in ASPL that disrupts functional p97 hexamers.
Arumughan, A., Roske, Y., Barth, C., Forero, L.L., Bravo-Rodriguez, K., Redel, A., Kostova, S., McShane, E., Opitz, R., Faelber, K., Rau, K., Mielke, T., Daumke, O., Selbach, M., Sanchez-Garcia, E., Rocks, O., Panakova, D., Heinemann, U., Wanker, E.E.(2016) Nat Commun 7: 13047-13047
- PubMed: 27762274 
- DOI: https://doi.org/10.1038/ncomms13047
- Primary Citation of Related Structures:  
5IFS, 5IFW - PubMed Abstract: 
Interaction mapping is a powerful strategy to elucidate the biological function of protein assemblies and their regulators. Here, we report the generation of a quantitative interaction network, directly linking 14 human proteins to the AAA+ ATPase p97, an essential hexameric protein with multiple cellular functions. We show that the high-affinity interacting protein ASPL efficiently promotes p97 hexamer disassembly, resulting in the formation of stable p97:ASPL heterotetramers. High-resolution structural and biochemical studies indicate that an extended UBX domain (eUBX) in ASPL is critical for p97 hexamer disassembly and facilitates the assembly of p97:ASPL heterotetramers. This spontaneous process is accompanied by a reorientation of the D2 ATPase domain in p97 and a loss of its activity. Finally, we demonstrate that overproduction of ASPL disrupts p97 hexamer function in ERAD and that engineered eUBX polypeptides can induce cell death, providing a rationale for developing anti-cancer polypeptide inhibitors that may target p97 activity.
Organizational Affiliation: 
Max Delbrück Center for Molecular Medicine, Robert-Rössle-Straße 10, 13125 Berlin, Germany.