Investigating the role of Snord116 in ribosome biology (Year 2)

Funding Summary

Through previous work using a new optimized method, Dr. Whipple discovered that Snord116, a driver of PWS, directly interacts with ribosomes, the machinery that produces proteins in the cell in mouse neurons. In this funded project, they will apply their optimized method to human neurons to ask if the interaction between SNORD116 and ribosomes is similar in humans. Then they will use advanced approaches to determine the effect that genetic deletion of Snord116 has on the proteins produced in mouse and human neurons.

Lay Abstract

This proposal aims to uncover the function of a critical gene called Snord116, which is missing in all individuals with PWS. Snord116 is thought to play a key role in disease, as individuals with small deletions that remove this gene show core PWS symptoms. However, understanding how Snord116 functions in neurons has been challenging due to the lack of tools that accurately detect its interacting partners. Recently, we optimized an improved method that allowed us to ask what Snord116 interacts with in mouse neurons. Our findings suggest that Snord116 interacts directly with ribosomes, the cellular machines responsible for protein synthesis. We hypothesize that Snord116 is required for producing ‘healthy’ ribosomes and that its absence might impair protein production in neurons, contributing to PWS symptoms.

In the last funding period, we applied this method to human neurons and observed a similar interaction between Snord116 and ribosomes. However, the interaction appears slightly different in mice and humans, so we now wonder if these differences may explain why the phenotypes of PWS mouse models don’t more closely resemble symptoms of individuals with PWS. Our initial studies using a specialized technique called Ribo-seq, which provides detailed information on ribosome activity across thousands of genes, hinted at subtle disruptions in protein production in mouse brain tissue lacking Snord116. Now, we plan to perform additional Ribo-seq experiments in mouse and human PWS model systems to further explore how protein production may be altered. More specifically, we will measure the precise locations and abundance of ribosomes in human neurons derived from iPSCs carrying PWS deletions and assess their regulation during early developmental stages in Snord116 deletion mice, when severe growth delays are beginning.

These foundational experiments seek to characterize the immediate molecular consequences of losing Snord116, providing insights that could lead to early therapeutic interventions. For instance, if protein production is impaired as a direct effect of Snord116 loss, future research might explore therapies targeting ribosome activity. Or, there may be ways to correct the production of key proteins altered in PWS. Subsequently, we plan to examine how these molecular changes influence neural circuits and neurophysiology in PWS models. Our expertise in state-of-the art methods in RNA biology and neurobiology, combined with my experience in the pharmaceutical industry, positions us to address these challenges. While our project focuses on early-stage research, I have personally witnessed the rapid transition from basic scientific discoveries to clinical trials in Angelman syndrome and remain optimistic about achieving similar progress for PWS.