Non-coding RNAs in neuronal differentiation and PWS

Funding Summary

We expect that discovering the direct functions of snoRNAs will uncover new mechanisms – as well as revealing the fundamental basis of PWS. We propose to create a wide picture of RNA-RNA and RNA-protein interactions during the development of brain cells, focusing on interactions of SNORD116, as well as SNORD115 and other ncRNAs synthesized from SNHG14. We will identify their direct interacting RNA and protein partners. Using mutant cell lines we will find specific changes in other RNAs and proteins resulting from their absence during neuronal differentiation. During the current project, we expect to make important discoveries about how brain-specific snoRNAs, particularly SNORD116, are regulated and function.

Dr. Theresa Strong, Director of Research Programs, shares details on this project in this short video clip. 

Lay Abstract

The genetic information in all organisms, including humans, is encoded in the sequences of very long molecules of DNA. However, to be used the data must be retrieved by copying into a related molecule called RNA. In this medium the information can be used to control all cellular processes. In consequence, RNA metabolism lies at the heart of the information processing systems that fundamentally distinguish living organisms from sets of biochemical reactions. The mRNAs encode the information needed to direct the synthesis of proteins. Others, termed non-coding RNAs (ncRNAs), function more directly. Characterized ncRNAs play many different roles, particularly in the machinery of protein synthesis, but it is very likely that more functions remain to be found. Prader-Willi syndrome can be caused by loss of ncRNAs that are synthesized from the SNHG14 locus. Among these are two sets of related RNAs collectively called SNORD115 and SNORD116, which are made by being cut out of a very long SNHG14 ncRNA. A gene deletion that removes only the part of SNHG14 that generates SNORD116 is enough to cause PWS. So these RNAs clearly have important functions - but we do not know what they are. SNORD116 is part of a much larger family of RNAs, termed small nucleolar RNAs (snoRNAs), that our group has studied since the 1980s. Most snoRNAs are expressed in all cells and are important in the manufacture of ribosomes, tiny machines that synthesize all the proteins. However, SNORD116 (and SNORD115) seem to be different. They are mainly expressed in the brain and do not seem to function in ribosome synthesis. We expect that discovering the direct functions of these snoRNAs will uncover new mechanisms – as well as revealing the fundamental basis of PWS. Many diseases start with small defects in the genome that ultimately cause serious health problems; as a small engine defect will ultimately cause a vehicle breakdown. Understanding of the first steps and the actual function of the defective component are needed for early interventions. In this project we will use methods well established in our lab to identify those early steps. We propose to create a wide picture of RNA-RNA and RNA-protein interactions during the development of brain cells, focusing on interactions of SNORD116, as well as SNORD115 and other ncRNAs synthesized from SNHG14. We will identify their direct interacting RNA and protein partners. Using mutant cell line we will find specific changes in other RNAs and proteins resulting from their absence during neuronal differentiation. We will then test a set of specific hypotheses for the molecular basis of these changes. The applicants are RNA-biologists, who bring insights and techniques to understand changes in neuronal RNA metabolism that ultimately lead to PWS. During the current project, we expect to make important discoveries about how brain-specific snoRNAs, particularly SNORD116, are regulated and function. Defects in these processes ultimately cause PWS and, in subsequent work, we will collaborate with neurobiologists to apply this basic understanding towards the development of molecular treatments, e.g. based on RNA therapeutics.