Interference of the complex between NCS-1 and Ric8a with phenothiazines regulates synaptic function and is an approach for fragile X syndrome.Mansilla, A., Chaves-Sanjuan, A., Campillo, N.E., Semelidou, O., Martinez-Gonzalez, L., Infantes, L., Gonzalez-Rubio, J.M., Gil, C., Conde, S., Skoulakis, E.M., Ferrus, A., Martinez, A., Sanchez-Barrena, M.J.
(2017) Proc. Natl. Acad. Sci. U.S.A. 114: E999-E1008
- PubMed: 28119500
- DOI: 10.1073/pnas.1611089114
- Primary Citation of Related Structures:
- PubMed Abstract:
The protein complex formed by the Ca <sup>2+ </sup> sensor neuronal calcium sensor 1 (NCS-1) and the guanine exchange factor protein Ric8a coregulates synapse number and probability of neurotransmitter release, emerging as a potential therapeutic tar ...
The protein complex formed by the Ca 2+ sensor neuronal calcium sensor 1 (NCS-1) and the guanine exchange factor protein Ric8a coregulates synapse number and probability of neurotransmitter release, emerging as a potential therapeutic target for diseases affecting synapses, such as fragile X syndrome (FXS), the most common heritable autism disorder. Using crystallographic data and the virtual screening of a chemical library, we identified a set of heterocyclic small molecules as potential inhibitors of the NCS-1/Ric8a interaction. The aminophenothiazine FD44 interferes with NCS-1/Ric8a binding, and it restores normal synapse number and associative learning in a Drosophila FXS model. The synaptic effects elicited by FD44 feeding are consistent with the genetic manipulation of NCS-1. The crystal structure of NCS-1 bound to FD44 and the structure-function studies performed with structurally close analogs explain the FD44 specificity and the mechanism of inhibition, in which the small molecule stabilizes a mobile C-terminal helix inside a hydrophobic crevice of NCS-1 to impede Ric8a interaction. Our study shows the drugability of the NCS-1/Ric8a interface and uncovers a suitable region in NCS-1 for development of additional drugs of potential use on FXS and related synaptic disorders.
Departamento de Neurobiología del Desarrollo, Instituto Cajal, Spanish National Research Council, 28002 Madrid, Spain.,Instituto de Química Médica, Spanish National Research Council, 28006 Madrid, Spain.,Centro de Investigaciones Biológicas, Spanish National Research Council, 28040 Madrid, Spain.,Division of Neuroscience, Biomedical Sciences Research Centre Alexander Fleming, 16672 Vari, Greece.,Departamento de Cristalografía y Biología Estructural, Instituto de Química Física Rocasolano, Spanish National Research Council, 28006 Madrid, Spain; firstname.lastname@example.org.,Departamento de Cristalografía y Biología Estructural, Instituto de Química Física Rocasolano, Spanish National Research Council, 28006 Madrid, Spain.