Structures of TorsinA and its disease-mutant complexed with an activator reveal the molecular basis for primary dystonia

The most common cause of early onset primary dystonia, a neuromuscular disease, is a glutamate deletion (ΔE) at position 302/303 of TorsinA, a AAA+ ATPase that resides in the endoplasmic reticulum. While the function of TorsinA remains elusive, the ΔE mutation is known to diminish binding of two TorsinA ATPase activators: lamina-associated protein 1 (LAP1) and its paralog, luminal domain like LAP1 (LULL1). Using a nanobody as a crystallization chaperone, we obtained a 1.4 Å crystal structure of human TorsinA in complex with LULL1. This nanobody likewise stabilized the weakened TorsinAΔE-LULL1 interaction, which enabled us to solve its structure at 1.4 Å also. A comparison of these structures shows, in atomic detail, the subtle differences in activator interactions that separate the healthy from the diseased state. This information may provide a structural platform for drug development, as a small molecule that rescues TorsinAΔE could serve as a cure for primary dystonia.

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Structural analysis of human dual-specificity phosphatase 22 complexed with a phosphotyrosine-like substrate

Acta Crystallographica Section F Structural Biology Communications ◽

10.1107/s2053230x15000217 ◽

2015 ◽

Vol 71 (2) ◽

pp. 199-205 ◽

Cited By ~ 4

Author(s):

George T. Lountos ◽

Scott Cherry ◽

Joseph E. Tropea ◽

David S. Waugh

Keyword(s):

Crystal Structure ◽

Structural Analysis ◽

Phosphatase Activity ◽

Small Molecule ◽

Molecular Basis ◽

Protein Tyrosine Phosphatases ◽

Simple Method ◽

Dual Specificity Phosphatase ◽

Dual Specificity ◽

Nitrophenyl Phosphate

4-Nitrophenyl phosphate (p-nitrophenyl phosphate, pNPP) is widely used as a small molecule phosphotyrosine-like substrate in activity assays for protein tyrosine phosphatases. It is a colorless substrate that upon hydrolysis is converted to a yellow 4-nitrophenolate ion that can be monitored by absorbance at 405 nm. Therefore, the pNPP assay has been widely adopted as a quick and simple method to assess phosphatase activity and is also commonly used in assays to screen for inhibitors. Here, the first crystal structure is presented of a dual-specificity phosphatase, human dual-specificity phosphatase 22 (DUSP22), in complex with pNPP. The structure illuminates the molecular basis for substrate binding and may also facilitate the structure-assisted development of DUSP22 inhibitors.

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The AAA+ ATPase TorsinA polymerizes into hollow tubes with a helical periodicity of 8.5 subunits per turn

10.1101/567099 ◽

2019 ◽

Author(s):

F. Esra Demircioglu ◽

Weili Zheng ◽

Alexander J. McQuown ◽

Nolan Maier ◽

Nicki Watson ◽

...

Keyword(s):

Electron Microscopy ◽

Neuromuscular Disease ◽

Central Channel ◽

Peptide Substrate ◽

Aaa Atpase ◽

Helical Reconstruction ◽

Cryo Electron Microscopy ◽

Primary Dystonia ◽

Aaa Atpases

AbstractTorsinA is an ER-resident AAA+ ATPase, whose single residue deletion of glutamate E303 results in the genetic neuromuscular disease primary dystonia. TorsinA is a highly unusual AAA+ ATPase in that it needs an external activator. Also, it appears not to thread a peptide substrate through a narrow central channel, in contrast to its closest structural homologs. Here, we examined the oligomerization of TorsinA to get closer to a molecular understanding of the still enigmatic function of it. We observe TorsinA to form helical filaments, which we analyzed by cryo-electron microscopy using helical reconstruction. The 4.4 Å structure reveals long hollow tubes with a helical periodicity of 8.5 subunits per turn, and an inner cavity of ∼4 nm diameter. We further show that the protein is able to induce tubulation of membranes in vitro, an observation that may reflect an entirely new characteristic of AAA+ ATPases. We discuss the implications of these observations for TorsinA function.

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How lamina-associated polypeptide 1 (LAP1) activates Torsin

eLife ◽

10.7554/elife.03239 ◽

2014 ◽

Vol 3 ◽

Cited By ~ 66

Author(s):

Brian A Sosa ◽

F Esra Demircioglu ◽

James Z Chen ◽

Jessica Ingram ◽

Hidde L Ploegh ◽

...

Keyword(s):

Crystal Structure ◽

Experimental Data ◽

Endoplasmic Reticulum ◽

Nuclear Envelope ◽

Microscopic Analysis ◽

Electron Microscopic ◽

Binding Motifs ◽

Primary Dystonia ◽

Arginine Finger ◽

Aaa Atpases

Lamina-associated polypeptide 1 (LAP1) resides at the nuclear envelope and interacts with Torsins, poorly understood endoplasmic reticulum (ER)-localized AAA+ ATPases, through a conserved, perinuclear domain. We determined the crystal structure of the perinuclear domain of human LAP1. LAP1 possesses an atypical AAA+ fold. While LAP1 lacks canonical nucleotide binding motifs, its strictly conserved arginine 563 is positioned exactly where the arginine finger of canonical AAA+ ATPases is found. Based on modeling and electron microscopic analysis, we propose that LAP1 targets Torsin to the nuclear envelope by forming an alternating, heterohexameric (LAP1-Torsin)3 ring, in which LAP1 acts as the Torsin activator. The experimental data show that mutation of arginine 563 in LAP1 reduces its ability to stimulate TorsinA ATPase hydrolysis. This knowledge may help scientists understand the etiology of DYT1 primary dystonia, a movement disorder caused by a single glutamate deletion in TorsinA.

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Faculty Opinions recommendation of X-ray crystal structures of the estrogen-related receptor-gamma ligand binding domain in three functional states reveal the molecular basis of small molecule regulation.

Faculty Opinions – Post-Publication Peer Review of the Biomedical Literature ◽

10.3410/f.1047292.497229 ◽

2006 ◽

Author(s):

Paul Webb

Keyword(s):

Ligand Binding ◽

Crystal Structures ◽

Small Molecule ◽

Molecular Basis ◽

Binding Domain ◽

Ligand Binding Domain ◽

X Ray ◽

Functional States ◽

Estrogen Related Receptor

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The Molecular Basis of Double-Strand DNA Break Repair: Crystal Structure of the RAD52/RPA Complex

10.21236/ada410170 ◽

2002 ◽

Author(s):

Doba D. Jackson ◽

Gloria Borgstahl

Keyword(s):

Crystal Structure ◽

Molecular Basis ◽

Dna Break ◽

Dna Break Repair ◽

Break Repair ◽

Double Strand Dna

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Familial thrombophilia associated with fibrinogen Paris V: Dusart syndrome

Blood ◽

10.1182/blood.v96.3.1191 ◽

2000 ◽

Vol 96 (3) ◽

pp. 1191-1193 ◽

Cited By ~ 15

Author(s):

Takashi Tarumi ◽

Danko Martincic ◽

Anne Thomas ◽

Robert Janco ◽

Mary Hudson ◽

...

Keyword(s):

Pulmonary Embolism ◽

Venous Thromboembolism ◽

Early Onset ◽

Family Members ◽

Initial Presentation ◽

Pulmonary Emboli ◽

Common Cause ◽

History Of ◽

Prophylactic Anticoagulation ◽

Fibrin Clots

Abstract We report on a family with a history of venous thromboembolism associated with fibrinogen Paris V (fibrinogen A-Arg554→Cys). Ten members experienced thrombotic events, including 4 with fatal pulmonary emboli. Pulmonary embolism was the presenting feature in 4. Those with the mutation and a history of thrombosis had somewhat higher fibrinogen concentrations than those with the mutation and no thrombosis (294 ± 70 mg/dL vs 217 ± 37 mg/dL, respectively). The Paris V mutation consistently caused a prolongation of the reptilase time, and fibrin clots containing the abnormal fibrinogen were more translucent than normal clots. Given the early onset of symptoms and the initial presentation with pulmonary embolism in some family members, it was justifiable to offer prophylactic anticoagulation with warfarin to carriers of the mutation. Fibrinogen Paris V has now been reported in 4 apparently unrelated families, indicating that it is a relatively common cause of dysfibrinogenemia-associated thrombosis.

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