1. Biochemistry and Chemical Biology
  2. Chromosomes and Gene Expression
Download icon

Translational Control: An emergency brake for protein synthesis

  1. Vladislava Hronová
  2. Leoš Shivaya Valášek  Is a corresponding author
  1. Institute of Microbiology ASCR, Czech Republic
Cite this article as: eLife 2017;6:e27085 doi: 10.7554/eLife.27085
1 figure


How translation can be stopped and started during protein synthesis.

Three of the main players in the control of translation act like the clutch (eIF2), brake (eIF2B) and accelerator (eIF5) in a car. (A) Once the translation of an mRNA molecule has started, a complex containing eIF2-GDP (which is inactive) and eIF5 leaves the ribosome. (B) eIF2B then out-competes eIF5 and mediates the exchange of GDP and GTP to yield eIF2-GTP (which is active). (C) eIF2-GTP and initiator Met-tRNA then form a ternary complex, which is stabilized by eIF5, and a new cycle of translation can begin. (D) Sometimes a cell has to reduce protein synthesis in response to stress or other factors, and this response starts with the phosphorylation (P) of a specific amino acid (Ser51) in eIF2. (E) This phosphorylation has important consequences: eIF2B is unable to mediate the exchange of GDP and GTP, and translation cannot proceed. (F, G) Jennings et al. show that if the phosphorylation of Ser51 occurs on eIF2 present in an existing ternary complex, the phosphoryl group allows eIF2B to out-compete eIF5: this means that eIF5 cannot stabilize the ternary complex, so the complex falls apart and translation is stopped completely.

Download links

A two-part list of links to download the article, or parts of the article, in various formats.

Downloads (link to download the article as PDF)

Download citations (links to download the citations from this article in formats compatible with various reference manager tools)

Open citations (links to open the citations from this article in various online reference manager services)