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

Huang, Bin; Guo, Qiang; Niedermeier, Marie L.; Cheng, Jingdong; Engler, Tatjana; Maurer, Melanie; Pautsch, Alexander; Baumeister, Wolfgang; Stengel, Florian; Kochanek, Stefan and Fernandez-Busnadiego, Ruben (2021): Pathological polyQ expansion does not alter the conformation of the Huntingtin-HAP40 complex. In: Structure, Vol. 29, No. 8: pp. 804-809

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.

• Item Type: Journal article
• Faculties: Chemistry and Pharmacy > Department of Biochemistry
• Research Centers: Center for Integrated Protein Science Munich (CIPSM)
• Subjects: 500 Science > 540 Chemistry
• ISSN: 0969-2126
• Language: English