Regulation of eukaryotic translation by the RACK1 protein: a platform for signalling molecules on the ribosome.
The receptor for activated C-kinase (RACK1) is a scaffold protein that is able to interact simultaneously with several signalling molecules. It binds to protein kinases and membrane-bound receptors in a regulated fashion. Interestingly, RACK1 is also a constituent of the eukaryotic ribosome, and a recent cryo-electron microscopy study localized it to the head region of the 40S subunit in the vicinity of the messenger RNA (mRNA) exit channel. RACK1 recruits activated protein kinase C to the ribosome, which leads to the stimulation of translation through the phosphorylation of initiation factor 6 and, potentially, of mRNA-associated proteins. RACK1 therefore links signal-transduction pathways directly to the ribosome, which allows translation to be regulated in response to cell stimuli. In addition, the fact that RACK1 associates with membrane-bound receptors indicates that it promotes the docking of ribosomes at sites where local translation is required, such as focal adhesions.
Nilsson
Jakob
J
Department of Molecular Biology, University of Aarhus, Gustav Wieds Vej 10C, DK-8000 Aarhus C, Denmark.
Sengupta
Jayati
J
Frank
Joachim
J
Nissen
Poul
P
D048868:Adaptor Proteins, Signal Transducing; D019204:GTP-Binding Proteins; D005786:Gene Expression Regulation / Q000502:physiology*; D006801:Humans; D009363:Neoplasm Proteins / Q000502:physiology*; D014176:Protein Biosynthesis / Q000502:physiology*; D012333:RNA, Messenger / Q000502:physiology; D000075370:Receptors for Activated C Kinase; D011956:Receptors, Cell Surface / Q000502:physiology*; D012270:Ribosomes / Q000502:physiology*; D029701:Saccharomyces cerevisiae Proteins / Q000502:physiology; D015398:Signal Transduction / Q000502:physiology*
C111825:ASC1 protein, S cerevisiae; D048868:Adaptor Proteins, Signal Transducing; D009363:Neoplasm Proteins; C419368:RACK1 protein, human; D012333:RNA, Messenger; D000075370:Receptors for Activated C Kinase; D011956:Receptors, Cell Surface; D029701:Saccharomyces cerevisiae Proteins; D019204:GTP-Binding Proteins