Pathological polyQ expansion does not alter the conformation of the Huntingtin-HAP40 complex

Bin Huang; Qiang Guo; Marie L Niedermeier; Jingdong Cheng; Tatjana Engler; Melanie Maurer; Alexander Pautsch; Wolfgang Baumeister; Florian Stengel; Stefan Kochanek; Rubén Fernández-Busnadiego

doi:10.1016/j.str.2021.04.003

Pathological polyQ expansion does not alter the conformation of the Huntingtin-HAP40 complex

Structure. 2021 Aug 5;29(8):804-809.e5. doi: 10.1016/j.str.2021.04.003. Epub 2021 Apr 27.

Authors

Affiliations

¹ Department of Gene Therapy, Ulm University, 89081, Ulm, Germany.
² Department of Molecular Structural Biology, Max Planck Institute of Biochemistry, 82152 Martinsried, Germany; State Key Laboratory of Protein and Plant Gene Research, School of Life Sciences and Peking-Tsinghua Center for Life Sciences, Peking University, 100871 Beijing, China.
³ Department of Biology, University of Konstanz, 78457 Konstanz, Germany; Konstanz Research School Chemical Biology, University of Konstanz, 78457 Konstanz, Germany.
⁴ Gene Center, Department of Biochemistry and Center for Integrated Protein Science Munich, Ludwig-Maximilians University, 81377 Munich, Germany.
⁵ Department of Medicinal Chemistry, Boehringer Ingelheim Pharma GmbH & Co. KG, 88397 Biberach an der Riß, Germany.
⁶ Department of Molecular Structural Biology, Max Planck Institute of Biochemistry, 82152 Martinsried, Germany.
⁷ Department of Biology, University of Konstanz, 78457 Konstanz, Germany; Konstanz Research School Chemical Biology, University of Konstanz, 78457 Konstanz, Germany. Electronic address: florian.stengel@uni-konstanz.de.
⁸ Department of Gene Therapy, Ulm University, 89081, Ulm, Germany. Electronic address: stefan.kochanek@uni-ulm.de.
⁹ Department of Molecular Structural Biology, Max Planck Institute of Biochemistry, 82152 Martinsried, Germany; Institute of Neuropathology, University Medical Center Göttingen, 37099 Göttingen, Germany; Cluster of Excellence "Multiscale Bioimaging: from Molecular Machines to Networks of Excitable Cells" (MBExC), University of Göttingen, 37075 Göttingen, Germany. Electronic address: ruben.fernandezbusnadiego@med.uni-goettingen.de.

PMID: 33909994
DOI: 10.1016/j.str.2021.04.003

Abstract

The abnormal amplification of a CAG repeat in the gene coding for huntingtin (HTT) leads to Huntington's disease (HD). At the protein level, this translates into the expansion of a polyglutamine (polyQ) stretch located at the HTT N terminus, which renders HTT aggregation prone by unknown mechanisms. Here we investigated the effects of polyQ expansion on HTT in a complex with its stabilizing interaction partner huntingtin-associated protein 40 (HAP40). Surprisingly, our comprehensive biophysical, crosslinking mass spectrometry and cryo-EM experiments revealed no major differences in the conformation of HTT-HAP40 complexes of various polyQ length, including 17QHTT-HAP40 (wild type), 46QHTT-HAP40 (typical polyQ length in HD patients), and 128QHTT-HAP40 (extreme polyQ length). Thus, HTT polyQ expansion does not alter the global conformation of HTT when associated with HAP40.

Keywords: HAP40; Huntington's disease; crosslinking; cryo-EM; cryoelectron microscopy; huntingtin; huntingtin-associated protein 40; mass spectrometry; polyQ; polyglutamine expansion.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Binding Sites
Cloning, Molecular
Cryoelectron Microscopy
HEK293 Cells
Humans
Huntingtin Protein / chemistry
Huntingtin Protein / genetics*
Huntington Disease / genetics*
Mass Spectrometry
Models, Molecular
Molecular Conformation
Nuclear Proteins / chemistry
Nuclear Proteins / metabolism*
Peptides / chemistry*
Peptides / genetics
Protein Binding

Substances

HAP40 protein, human
HTT protein, human
Huntingtin Protein
Nuclear Proteins
Peptides
polyglutamine