BN Seminar - Marvin Tanenbaum (Hubrecht Institute): 'Real-time observation of translation of single mRNA molecules in live cells'



16:00 hrs




Regulation of mRNA translation, the process by which ribosomes decode mRNAs into polypeptides, is used to tune cellular protein levels. Currently, methods for observing the complete process of translation from single mRNAs in vivo are unavailable. We have developed a method for the long-term (>1 hr) imaging of single mRNAs undergoing hundreds of rounds of translation in live cells, enabling quantitative measurements of ribosome initiation, elongation and stalling. This approach reveals a surprising heterogeneity in the translation of individual mRNAs within the same cell, including rapid and reversible transitions between a translating and non-translating state, and substantial heterogeneity in ribosome pausing at regulatory pause sites. Applying this method to the cell cycle gene Emi1, we find strong overall repression of translation initiation by specific 5’UTR sequences, but individual mRNA molecules in the same cell can exhibit dramatically different translational efficiencies. The ability to observe translation of single mRNA molecules in live cells for long periods of time provides a powerful approach to study translation regulation.