Pepponi, R. | bioRxiv Science

bioRxiv2026

A CYFIP1-Inspired Peptidomimetic Modulates eIF4E-Dependent Translational Control in Cancer and Neurodevelopmental Disorders

The eukaryotic translation initiation factor 4E (eIF4E) is a central regulator of cap-dependent translation and a compelling pharmacological target in disorders marked by protein synthesis dysregulation, including cancer and Fragile X Syndrome (FXS). Among endogenous eIF4E regulators, the CYFIP1-eIF4E interaction is uniquely selective, offering a framework for designing targeted translation modulators. Here, we report Cy-9B, a rationally engineered, stapled peptidomimetic derived from CYFIP1 that binds eIF4E, disrupts eIF4E-eIF4G complex, and suppresses cap-dependent translation. Enhanced-sampling free-energy simulations reveal that Cy-9B engages eIF4E through a non-canonical binding mode. Cy-9B exhibits drug-like properties, including high proteolytic stability and nanomolar affinity. Functionally, Cy-9B inhibits lung cancer cell proliferation, migration, and invasion. In neurodevelopmental disease models, Cy-9B partially normalizes excessive translation in FXS hippocampal neurons and rescues social behavior deficits in a Cyfip1 haploinsufficient Drosophila melanogaster model, restoring wild-type-like performance. Cy-9B emerges as a first-in-class therapeutic candidate for disorders sharing translational dysregulation, highlighting targeted modulation of eIF4E as a broadly applicable and physiologically compatible therapeutic strategy.

biochemistry↗

bioRxiv2023

Cortical neurons obtained from patient-derived GNAO1 iPSCs show altered differentiation and functional properties

Pathogenic variants in the GNAO1 gene, encoding the alpha subunit of an inhibitory heterotrimeric guanine nucleotide-binding protein (Go) highly expressed in the mammalian brain, have been linked to encephalopathy characterized by different combinations of neurological symptoms, including developmental delay, hypotonia, epilepsy and hyperkinetic movement disorder with life-threatening paroxysmal exacerbations. Currently, there are only symptomatic treatments, and little is known about the pathophysiology of GNAO1-related disorders. Here, we report the characterization of a new in vitro model system based on patient-derived induced pluripotent stem cells (hiPSCs) carrying the recurrent p.G203R amino acid substitution in Go, and a CRISPR-Cas9-genetically corrected isogenic control line. RNA-Seq analysis highlighted aberrant cell fate commitment in neuronal progenitor cells carrying the p.G203R pathogenic variant. Upon differentiation into cortical neurons, patients cells showed reduced expression of early neural genes and increased expression of astrocyte markers, as well as premature and defective differentiation processes leading to aberrant formation of neuronal rosettes. Of note, comparable defects in gene expression and in the morphology of neural rosettes were observed in hiPSCs from an unrelated individual harboring the same GNAO1 variant. Functional characterization showed lower basal intracellular free calcium concentration ([Ca2+]i), reduced frequency of spontaneous activity, and a smaller response to several neurotransmitters in 40- and 50-days differentiated p.G203R neurons compared to control cells. These findings suggest that the GNAO1 pathogenic variant causes a neurodevelopmental phenotype characterized by aberrant differentiation of both neuronal and glial populations leading to a significant alteration of neuronal communication and signal transduction.

neuroscience↗