Regulated mRNA stability and translation in neural stem cell development (360G-Wellcome-209412_Z_17_Z)

Understanding how the billions of varied cells in the human brain develop from a small number of neural stem cells (NSCs) is a central question in biology and medicine. This highly complex process has largely been explained by transcriptional regulation dictating the levels of protein expression in stem cells and their progeny. Using novel single molecule approaches to quantitate transcription and protein levels, we have discovered functionally important conserved examples where the levels of transcription and protein expression do not correlate. These include pros/prox1, the regulator of NSC proliferation and differentiation and myc, the proto-oncogene regulator of stem cell size. We will characterise the mechanism of post-transcriptional regulation of pros, myc and 21 additional functionally important examples we have discovered, all of which have extremely long 3’UTRs that are bound and regulated by the same conserved RNA binding proteins, Syp and Imp. We will also measure, genome-wide, mRNA stability and characterise the trans-acting factors and cis-acting signals regulating stability and translation. The proposed programme will characterise a hitherto under-studied layer of regulation acting in addition to transcription in complex tissues, providing major new mechanistic insights into how the brain develops in health and disease.