Post-transcriptional regulation of mRNAs plays a major role in determining the proteome and thus cell fate. Such regulation is implemented by RNA-binding proteins, which control an mRNA’s splicing, subcellular localization, translation and stability. Post-transcriptional regulation plays crucial roles in neuronal development and function, and many RNA-binding proteins have been implicated in autism spectrum disorder (ASD). To date, mutations in 51 RNA-binding proteins have been strongly implicated in ASD via human genetic studies. Howard Lipshitz and his team hypothesize that these proteins influence ASD through their critical roles in post-transcriptional regulation during neurogenesis.

In this project, Howard Lipshitz aims to: (1) produce a resource of phage-displayed synthetic antibodies for the study of these ASD-associated RNA-binding proteins, (2) define the post-transcriptional regulatory status of all the mRNAs in induced pluripotent stem cell (iPSC)-derived neural progenitors and neurons, and (3) identify the target RNAs of eight high-priority ASD-associated RNA-binding proteins in IPSC-derived neural progenitors and neurons using the synthetic antibodies, thus predicting the molecular functions of the proteins, with experimental validation of a subset of the predictions.

The resources and data produced will overcome the current lack of a system-wide understanding of ASD-associated RNA-binding proteins and their role in post-transcriptional regulation in typical human neurons. The synthetic antibody collection generated in aim 1 will provide an inexpensive and inexhaustible community resource for future experimental studies of ASD. The data collected in aim 2 will characterize the post-transcriptional regulatory status of all of the mRNAs in an ASD-relevant iPSC model, while aim 3 will serve as proof-of-principle for how to utilize the resources generated in aim 1 and 2 to study the normal functions of ASD-associated RNA-binding proteins. With a firm grasp of their normal function, future research using these resources will facilitate studies to elucidate how disruption of these molecular functions contributes to ASD.