Open Peer Review Any reports and responses or comments on the article can be found at the end of the article. RESEARCH ARTICLE Impact of pathogenic mutations of the GLUT1 glucose transporter on channel dynamics using ConsDYN enhanced sampling [version 1; peer review: awaiting peer review] Halima Mouhib , Akiko Higuchi , Sanne Abeln , Kei Yura , K. Anton Feenstra 3 Laboratoire Modélisation et Simulation Multi Echelle (MSME) - UMR 8208 CNRS, Université Paris-Est Marne-la-Vallée, Champs-sur-Marne, France Graduate School of Frontier Sciences, The University of Tokyo, Tokyo, Japan Dept. Computer Science, Integrative Bioinformatics, Vrije Universiteit, Amsterdam, The Netherlands Graduate School of Humanities and Sciences, Ochanomizu University, Tokyo, Japan School of Advanced Science and Engineering, Waseda University, Tokyo, Japan Abstract The solute carrier (SLC) family of membrane proteins is a large Background: class of transporters for many small molecules that are vital for the cell. Several pathogenic mutations are reported in the glucose transporter subfamily SLC2, causing Glut1-deficiency syndrome (GLUT1DS1, GLUT1DS2), epilepsy (EIG2) and cryohydrocytosis with neurological defects (Dystonia-9). Understanding the link between these mutations and transporter dynamics is crucial to elucidate their role in the dysfunction of the underlying transport mechanism. Predictions from SIFT and PolyPhen provided an impression of the Methods: impact upon mutation in the highly conserved RXGRR motifs, but no clear differentiation could be made by these methods between pathogenic and non-pathogenic mutations. Therefore, to identify the molecular effects on the transporter function, insight from molecular dynamic simulations is required. We studied a variety of pathogenic and non-pathogenic mutations, using a newly developed coarse-grained simulation approach ‘ConsDYN’, which allows the sampling of both inward-open and outward-occluded states. To guarantee the sampling of large conformational changes, we only include conserved restraints of the elastic network introduced upon coarse-graining, which showed similar reference distances between the two conformational states (≤1 Å difference). We capture the ‘conserved dynamics’ between both states using Results: ConsDYN. Simultaneously, it allowed us to considerably lower the computational costs of our study. This approach is sufficiently sensitive to capture the effect of different mutations, and our results clearly indicate that the pathogenic mutation in GLUT1, G91D, situated at the highly conserved RXGRR motif between helices 2 and 3, has a strong impact on channel function, as it blocks the protein from sampling both conformational states. Using our approach, we can explain the pathogenicity of the Conclusions: mutation G91D when we observe the configurations of the transmembrane helices, suggesting that their relative position is crucial for the correct functioning of the GLUT1 protein. 1 2 3 4,5 3 1 2 3 4 5 Referee Status: AWAITING PEER REVIEW 22 Mar 2019, :322 ( First published: 8 ) https://doi.org/10.12688/f1000research.18553.1 22 Mar 2019, :322 ( Latest published: 8 ) https://doi.org/10.12688/f1000research.18553.1 v1 Page 1 of 10 F1000Research 2019, 8:322 Last updated: 30 MAR 2019