Ribosome Profiling

Source: Ingolia et al (2009). Genome-Wide Analysis in Vivo of Translation with Nucleotide
Resolution Using Ribosome Profiling. Science 324: 218-223.

Proteomics is the game, but due to technical difficulties in the direct quantification of protein types in the cell, we have instead been using transcriptome measurements as a proxy for protein expression. This is a decent proxy but far from perfect. In this paper, the authors bring us a step closer to protein quantification through measuring the portion of transcriptome that is actually being translated. They combine the ribosome-mediated protection of traslated RNA molecules with the power of deep sequencing to determine the ribosome positionings at a single nt resolution.

What the authors found?
1. There is an excess of ribosomes bound to the first 30-40 codons; a quantity which drops substantially in the later codons.
2. uORFs are quite widespread, resulting in a high ribosome presence in the 5'UTR.