Stability and flexibility of full-length human oligodendrocytic QKI6
|Author:||Raasakka, Arne1,2; Kursula, Petri1,2|
1Department of Biomedicine, Faculty of Medicine, University of Bergen, Bergen, Norway
2Faculty of Biochemistry and Molecular Medicine & Biocenter Oulu, University of Oulu, Oulu, Finland
|Online Access:||PDF Full Text (PDF, 1.6 MB)|
|Persistent link:|| http://urn.fi/urn:nbn:fi-fe202003138153
|Publish Date:|| 2020-03-13
Objective: Oligodendrocytes account for myelination in the central nervous system. During myelin compaction, key proteins are translated in the vicinity of the myelin membrane, requiring targeted mRNA transport. Quaking isoform 6 (QKI6) is a STAR domain-containing RNA transport protein, which binds a conserved motif in the 3′-UTR of certain mRNAs, affecting the translation of myelination-involved proteins. RNA binding has been earlier structurally characterized, but information about full-length QKI6 conformation is lacking. Based on known domains and structure predicitons, we expected full-length QKI6 to be flexible and carry disordered regions. Hence, we carried out biophysical and structural characterization of human QKI6.
Results: We expressed and purified full-length QKI6 and characterized it using mass spectrometry, light scattering, small-angle X-ray scattering, and circular dichroism spectroscopy. QKI6 was monodisperse, folded, and mostly dimeric, being oxidation-sensitive. The C-terminal tail was intrinsically disordered, as predicted. In the absence of RNA, the RNA-binding subdomain is likely to present major flexibility. In thermal stability assays, a double sequential unfolding behaviour was observed in the presence of phosphate, which may interact with the RNA-binding domain. The results confirm the flexibility and partial disorder of QKI6, which may be functionally relevant.
BMC research notes
|Type of Publication:||
A1 Journal article – refereed
|Field of Science:||
1182 Biochemistry, cell and molecular biology
This work was financially supported by the Sigrid Jusélius Foundation, the Emil Aaltonen Foundation, and the Department of Biochemistry, University of Oulu.
© The Author(s) 2019. Open Access. This article is distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated.