TY - JOUR
T1 - Coupled activation and degradation of eEF2K regulates protein synthesis in response to genotoxic stress
AU - Kruiswijk, Flore
AU - Yuniati, Laurensia
AU - Magliozzi, Roberto
AU - Low, Teck Yew
AU - Lim, Ratna
AU - Bolder, Renske
AU - Mohammed, Shabaz
AU - Proud, Christopher G.
AU - Heck, Albert J.R.
AU - Pagano, Michele
AU - Guardavaccaro, Daniele
PY - 2012/6/5
Y1 - 2012/6/5
N2 - The kinase eEF2K [eukaryotic elongation factor 2 (eEF2) kinase] controls the rate of peptide chain elongation by phosphorylating eEF2, the protein that mediates the movement of the ribosome along the mRNA by promoting translocation of the transfer RNA from the A to the P site in the ribosome. eEF2K-mediated phosphorylation of eEF2 on threonine 56 (Thr 56) decreases its affinity for the ribosome, thereby inhibiting elongation. Here, we show that in response to genotoxic stress, eEF2K was activated by AMPK (adenosine monophosphate-activated protein kinase)-mediated phosphorylation on serine 398. Activated eEF2K phosphorylated eEF2 and induced a temporary ribosomal slowdown at the stage of elongation. Subsequently, during DNA damage checkpoint silencing, a process required to allow cell cycle reentry, eEF2K was degraded by the ubiquitin-proteasome system through the ubiquitin ligase SCF βTrCP (Skp1-Cul1-F-box protein, β-transducin repeat-containing protein) to enable rapid resumption of translation elongation. This event required autophosphorylation of eEF2K on a canonical βTrCP-binding domain. The inability to degrade eEF2K during checkpoint silencing caused sustained phosphorylation of eEF2 on Thr 56 and delayed the resumption of translation elongation. Our study therefore establishes a link between DNA damage signaling and translation elongation.
AB - The kinase eEF2K [eukaryotic elongation factor 2 (eEF2) kinase] controls the rate of peptide chain elongation by phosphorylating eEF2, the protein that mediates the movement of the ribosome along the mRNA by promoting translocation of the transfer RNA from the A to the P site in the ribosome. eEF2K-mediated phosphorylation of eEF2 on threonine 56 (Thr 56) decreases its affinity for the ribosome, thereby inhibiting elongation. Here, we show that in response to genotoxic stress, eEF2K was activated by AMPK (adenosine monophosphate-activated protein kinase)-mediated phosphorylation on serine 398. Activated eEF2K phosphorylated eEF2 and induced a temporary ribosomal slowdown at the stage of elongation. Subsequently, during DNA damage checkpoint silencing, a process required to allow cell cycle reentry, eEF2K was degraded by the ubiquitin-proteasome system through the ubiquitin ligase SCF βTrCP (Skp1-Cul1-F-box protein, β-transducin repeat-containing protein) to enable rapid resumption of translation elongation. This event required autophosphorylation of eEF2K on a canonical βTrCP-binding domain. The inability to degrade eEF2K during checkpoint silencing caused sustained phosphorylation of eEF2 on Thr 56 and delayed the resumption of translation elongation. Our study therefore establishes a link between DNA damage signaling and translation elongation.
UR - http://www.scopus.com/inward/record.url?scp=84862116855&partnerID=8YFLogxK
U2 - 10.1126/scisignal.2002718
DO - 10.1126/scisignal.2002718
M3 - Article
C2 - 22669845
AN - SCOPUS:84862116855
SN - 1945-0877
VL - 5
JO - Science Signaling
JF - Science Signaling
IS - 227
M1 - ra40
ER -