ESPCI web site
Non-uniform speed of translation : Stochastic fluctuations or programmed pausing
Translation of the genetic information from a nucleotide sequence into a functional protein is an essential biological process. The translation machinery, the ribosome, is a central player that translates the genetic information stored in the messenger RNA codon by codon. Multiple auxiliary factors with different molecular mass and concentration participate also in this process. They reach the ribosome solely by diffusion, which exerts a powerful selective force on the rate the ribosomes progress along mRNAs and consequently on the translation fidelity. We use cell-wide approaches to quantitatively assess the translation efficiency and ribosome occupancy with nucleotide resolution. Our data reveal that translation processes with non-uniform velocity including also some transient pauses which provide a kinetic window to synchronize translation of the genetic information with other cellular processes, including protein folding. Using predictive mathematical modeling we assess the alterations in translational behavior under stress. Different types of environmental stress have strictly different effect on translation fidelity.