Fused in sarcoma (FUS) is involved in many processes of RNA metabolism. FUS and another RNA binding protein, TDP-43, are implicated in amyotrophic lateral sclerosis (ALS). It is significant to characterize the RNA recognition motif (RRM) of FUS as its nucleic acid binding properties are unclear. More importantly, abolishing the RNA binding ability of the RRM domain of TDP43 was reported to suppress the neurotoxicity of TDP-43 in Drosophila. The sequence of FUS-RRM varies significantly from canonical RRMs, but the solution structure of FUS-RRM determined by NMR showed a similar overall folding as other RRMs. We found that FUS-RRM directly bound to RNA and DNA and the binding affinity was in the micromolar range as measured by surface plasmon resonance and NMR titration. The nucleic acid binding pocket in FUS-RRM is significantly distorted since several critical aromatic residues are missing. An exceptionally positively charged loop in FUS-RRM, which is not found in other RRMs, is directly involved in the RNA/DNA binding. Substituting the lysine residues in the unique KK loop impaired the nucleic acid binding and altered FUS subcellular localization. The results provide insights into the nucleic acid binding properties of FUS-RRM and its potential relevance to ALS.
|Number of pages||11|
|Journal||Biochimica et Biophysica Acta - Molecular Basis of Disease|
|State||Published - Feb 2013|
Bibliographical noteFunding Information:
This work was supported by the National Major Basic Research Program of China ( 2011CB910503 ), the National Natural Science Foundation of China ( 31070657 , 31190062 and 31021062 ), and the Knowledge Innovation Program of the Chinese Academy of Sciences ( KSCX2-YW-R-154 and KSCX2-EW-J-3 ) to W. F. and W. G.; the National Institutes of Health grant R01NS077284 and the ALS Association grant 6SE340 to H. Z. The NMR spectrometer used in this work was supported by the Chinese Academy of Sciences Protein Science Core Facility Center in the Institute of Biophysics. We thank Dr. Jozsef Gal for critical reading of the manuscript, and Dr. Craig Vander Kooi for valuable discussion. We thank Dr. Yingang Feng for help with the 3D NMR data collecting and Yuanyuan Chen for the SPR technical support.
- Amyotrophic lateral sclerosis
- Fused in sarcoma
- Nucleic acid binding
- RNA recognition motif
- Surface plasmon resonance
ASJC Scopus subject areas
- Molecular Medicine
- Molecular Biology