title: Arresting a Torsin ATPase reshapes the endoplasmic reticulum.
abstract: Torsins are membrane-tethered AAA+ ATPases residing in the nuclear envelope (NE) and endoplasmic reticulum (ER). Here, we show that the induction of a conditional, dominant-negative TorsinB variant provokes a profound reorganization of the endomembrane system into foci containing double membrane structures that are derived from the ER. These double-membrane sinusoidal structures are formed by compressing the ER lumen to a constant width of 15 nm, and are highly enriched in the ATPase activator LULL1. Further, we define an important role for a highly conserved aromatic motif at the C terminus of Torsins. Mutations in this motif perturb LULL1 binding, reduce ATPase activity, and profoundly limit the induction of sinusoidal structures.
authors.affiliation: From the Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, Connecticut 06520.
authors.forename: April E
authors.initials: AE
authors.lastname: Rose
authors.forename: Chenguang
authors.initials: C
authors.lastname: Zhao
authors.forename: Elizabeth M
authors.initials: EM
authors.lastname: Turner
authors.forename: Anna M
authors.initials: AM
authors.lastname: Steyer
authors.forename: Christian
authors.initials: C
authors.lastname: Schlieker
mesh_terms: D000251:Adenosine Triphosphatases / Q000235:genetics / Q000378:metabolism*; D020816:Amino Acid Motifs; D002352:Carrier Proteins / Q000235:genetics / Q000378:metabolism; D004721:Endoplasmic Reticulum / Q000201:enzymology* / Q000378:metabolism*; D006367:HeLa Cells; D006801:Humans; D007425:Intracellular Membranes / Q000201:enzymology*; D008565:Membrane Proteins / Q000235:genetics / Q000378:metabolism; D018832:Molecular Chaperones / Q000235:genetics / Q000378:metabolism*; D009154:Mutation
chemical_list: D002352:Carrier Proteins; D008565:Membrane Proteins; D018832:Molecular Chaperones; C500006:TOR1AIP2 protein, human; C491547:TOR1B protein, human; D000251:Adenosine Triphosphatases
keywords: AAA+ ATPase; ATPases; Electron Microscopy (EM); Endoplasmic Reticulum(ER); Enzyme Mechanisms; Membrane Structure; Torsin