- Arumughan A, Roske Y, Barth C, Forero LL, 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 EE
- Quantitative interaction mapping reveals an extended UBX domain in ASPL that disrupts functional p97 hexamers.
- Nat Commun. 2016 Oct 20;7:13047. doi: 10.1038/ncomms13047.
- 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.