Skip to main content
Kent Academic Repository

Molecular mechanisms for the control of translation by insulin

Proud, Christopher G., Denton, Richard M. (1997) Molecular mechanisms for the control of translation by insulin. Biochemical Journal, 328 . pp. 329-341. ISSN 0264-6021. (The full text of this publication is not currently available from this repository. You may be able to access a copy if URLs are provided) (KAR id:17888)

The full text of this publication is not currently available from this repository. You may be able to access a copy if URLs are provided.
Official URL:
http://www.pubmedcentral.nih.gov/articlerender.fcg...

Abstract

Insulin acutely stimulates protein synthesis in mammalian cells, and this involves activation of the process of mRNA translation. mRNA translation is a complex multi-step process mediated by proteins termed translation factors. Several translation factors are regulated in response to insulin, often as a consequence of changes in their states of phosphorylation. The initiation factor eIF4E binds to the cap structure at the 5'-end of the mRNA and mediates assembly of an initiation-factor complex termed eIF4F. Assembly of this complex can be regulated by eIF4E-binding proteins (4E-BPs), which inhibit eIF4F complex assembly. Insulin induces phosphorylation of the 4E-BPs, resulting in alleviation of the inhibition. This regulatory mechanism is likely to be especially important for the control of the translation of specific mRNAs whose 5'-untranslated regions (5'-UTRs) are rich in secondary structure. Translation of another class of mRNAs, those with 5'-UTRs containing polypyrimidine tracts is also activated by insulin and this, like phosphorylation of the 4E-BPs, appears to involve the rapamycin-sensitive signalling pathway which leads to activation of the 70 kDa ribosomal protein S6 kinase (p70 S6 kinase) and the phosphorylation of the ribosomal protein S6. Overall stimulation of translation may involve activation of initiation factor eIF2B, which is required for all initiation events. This effect is dependent upon phosphatidylinositol 3-kinase and may involve the inactivation of glycogen synthase kinase-3 and consequent dephosphorylation of eIF2B, leading to its activation. Peptide-chain elongation can also be activated by insulin, and this is associated with the dephosphorylation and activation of elongation factor eEF2, probably as a consequence of the insulin-induced reduction in eEF2 kinase activity. Thus multiple signalling pathways acting on different steps in translation are involved in the activation of this process by insulin and lead both to general activation of translation and to the selective regulation of specific mRNAs.

Item Type: Article
Subjects: Q Science > QP Physiology (Living systems) > QP517 Biochemistry
Q Science > QP Physiology (Living systems) > QP506 Molecular biology
Divisions: Divisions > Division of Natural Sciences > Biosciences
Depositing User: T.J. Sango
Date Deposited: 21 May 2009 13:01 UTC
Last Modified: 16 Nov 2021 09:56 UTC
Resource URI: https://kar.kent.ac.uk/id/eprint/17888 (The current URI for this page, for reference purposes)

University of Kent Author Information

Proud, Christopher G..

Creator's ORCID:
CReDIT Contributor Roles:
  • Depositors only (login required):

Total unique views for this document in KAR since July 2020. For more details click on the image.