Submit Data |  Help |  Video Tutorials |  News |  Publications |  FTP Download |  REST API |  Citing RGD |  Contact   

Inactivation of eIF2B and phosphorylation of PHAS-I in heat-shocked rat hepatoma cells.

Authors: Scheper, GC  Mulder, J  Kleijn, M  Voorma, HO  Thomas, AA  Van Wijk, R 
Citation: Scheper GC, etal., J Biol Chem. 1997 Oct 24;272(43):26850-6.
Pubmed: (View Article at PubMed) PMID:9341116

Various factors are involved in the heat shock-induced inhibition of protein synthesis. Changes upon heat shock in phosphorylation, leading to inactivation, of eukaryotic initiation factors (eIFs) eIF2 and eIF4E have been shown for several cell types. However, in mammalian cells these changes occur at temperatures of 43 degrees C or higher while protein synthesis is already affected at milder heat shock temperatures. In searching for the cause for the inhibition of protein synthesis, the regulation of eIF2 and eIF4E by additional factors was analyzed. In this respect, the activity of eIF2B was measured during and after heat shock. A very clear correlation was found between the activity of this guanine exchange factor and the levels of protein synthesis, also at mild heat shock conditions. Changes in the phosphorylation of eIF4E and of the eIF4E-binding protein PHAS-I were also analyzed. Surprisingly, in H35 cells as well as in some other cell lines, PHAS-I phosphorylation was increased by heat shock, whereas in others it was decreased. Therefore, decreasing the eIF4E availability under stressful conditions does not seem to be a general mechanism to inhibit protein synthesis by heat shock. Regulation of eIF2B activity appears to be the main mechanism to control translation initiation after heat shock at mild temperatures.

Annotation

Gene Ontology Annotations
Objects Annotated

Additional Information

 
CRRD Object Information
CRRD ID: 8554311
Created: 2014-05-08
Species: All species
Last Modified: 2014-05-08
Status: ACTIVE



NHLBI Logo

RGD is funded by grant HL64541 from the National Heart, Lung, and Blood Institute on behalf of the NIH.