title: The p97-FAF1 protein complex reveals a common mode of p97 adaptor binding.
abstract: p97, also known as valosin-containing protein, is a versatile participant in the ubiquitin-proteasome system. p97 interacts with a large network of adaptor proteins to process ubiquitylated substrates in different cellular pathways, including endoplasmic reticulum-associated degradation and transcription factor activation. p97 and its adaptor Fas-associated factor-1 (FAF1) both have roles in the ubiquitin-proteasome system during NF-κB activation, although the mechanisms are unknown. FAF1 itself also has emerging roles in other cell-cycle pathways and displays altered expression levels in various cancer cell lines. We have performed a detailed study the p97-FAF1 interaction. We show that FAF1 binds p97 stably and in a stoichiometry of 3 to 6. Cryo-EM analysis of p97-FAF1 yielded a 17 Å reconstruction of the complex with FAF1 above the p97 ring. Characteristics of p97-FAF1 uncovered in this study reveal common features in the interactions of p97, providing mechanistic insight into how p97 mediates diverse functionalities.
authors.affiliation: Centre for Structural Biology, Department of Life Sciences, Imperial College London, South Kensington Campus, London SW7 2AZ, United Kingdom.
authors.forename: Caroline A
authors.initials: CA
authors.lastname: Ewens
authors.affiliation: Centre for Structural Biology, Department of Life Sciences, Imperial College London, South Kensington Campus, London SW7 2AZ, United Kingdom.
authors.forename: Silvia
authors.initials: S
authors.lastname: Panico
authors.affiliation: Centre for Structural Biology, Department of Life Sciences, Imperial College London, South Kensington Campus, London SW7 2AZ, United Kingdom.
authors.forename: Patrik
authors.initials: P
authors.lastname: Kloppsteck
authors.affiliation: Centre for Structural Biology, Department of Life Sciences, Imperial College London, South Kensington Campus, London SW7 2AZ, United Kingdom.
authors.forename: Ciaran
authors.initials: C
authors.lastname: McKeown
authors.affiliation: Department of Chemistry, University of Oxford, South Parks Road, Oxford OX1 3TA, United Kingdom.
authors.forename: Ima-Obong
authors.initials: IO
authors.lastname: Ebong
authors.affiliation: Department of Chemistry, University of Oxford, South Parks Road, Oxford OX1 3TA, United Kingdom.
authors.forename: Carol
authors.initials: C
authors.lastname: Robinson
authors.affiliation: Centre for Structural Biology, Department of Life Sciences, Imperial College London, South Kensington Campus, London SW7 2AZ, United Kingdom.
authors.forename: Xiaodong
authors.initials: X
authors.lastname: Zhang
authors.affiliation: Centre for Structural Biology, Department of Life Sciences, Imperial College London, South Kensington Campus, London SW7 2AZ, United Kingdom. Electronic address: p.freemont@imperial.ac.uk.
authors.forename: Paul S
authors.initials: PS
authors.lastname: Freemont
mesh_terms: D048868:Adaptor Proteins, Signal Transducing / Q000378:metabolism*; D000251:Adenosine Triphosphatases / Q000378:metabolism*; D051017:Apoptosis Regulatory Proteins; D002151:Calorimetry; D018797:Cell Cycle Proteins / Q000378:metabolism*; D020285:Cryoelectron Microscopy; D011485:Protein Binding; D014461:Ultracentrifugation; D000074405:Valosin Containing Protein
chemical_list: D048868:Adaptor Proteins, Signal Transducing; D051017:Apoptosis Regulatory Proteins; D018797:Cell Cycle Proteins; C490780:FAF1 protein, human; D000251:Adenosine Triphosphatases; C000614178:VCP protein, human; D000074405:Valosin Containing Protein
keywords: ATPases; Electron Microscopy (EM); FAF1; Fas; Isothermal Titration Calorimetry; Protein Cross-linking; p97