The University of Southampton
University of Southampton Institutional Repository

Intracellular sensing of amino acids in Xenopus laevis oocytes stimulates p70 S6 kinase in a target of rapamycin-dependent manner

Christie, G.R., Hajduch, E., Hundal, H.S., Proud, C.G. and Taylor, P.M. (2002) Intracellular sensing of amino acids in Xenopus laevis oocytes stimulates p70 S6 kinase in a target of rapamycin-dependent manner The Journal of Biological Chemistry, 277, pp. 9952-9957. (doi:10.1074/jbc.M107694200).

Record type: Article

Abstract

Amino acids exert modulatory effects on proteins involved in control of mRNA translation in animal cells through the target of rapamycin (TOR) signaling pathway. Here we use oocytes of Xenopus laevis to investigate mechanisms by which amino acids are "sensed" in animal cells. Small (~48%) but physiologically relevant increases in intracellular but not extracellular total amino acid concentration (or Leu or Trp but not Ala, Glu, or Gln alone) resulted in increased phosphorylation of p70S6K and its substrate ribosomal protein S6. This response was inhibited by rapamycin, demonstrating that the effects require the TOR pathway. Alcohols of active amino acids substituted for amino acids with lower efficiency. Oocytes were refractory to changes in external amino acid concentration unless surface permeability of the cell to amino acids was increased by overexpression of the System L amino acid transporter. Amino acid-induced, rapamycin-sensitive activation of p70S6K was conferred when System L-expressing oocytes were incubated in extracellular amino acids, supporting intracellular localization of the putative amino acid sensor. In contrast to lower eukaryotes such as yeast, which possess an extracellular amino acid sensor, our findings provide the first direct evidence for an intracellular location for the putative amino acid sensor in animal cells that signals increased amino acid availability to TOR/p70S6K.

Full text not available from this repository.

More information

Published date: 1 March 2002

Identifiers

Local EPrints ID: 56501
URI: http://eprints.soton.ac.uk/id/eprint/56501
ISSN: 0021-9258
PURE UUID: b269c304-36d7-448d-ae8e-5c58b861e818

Catalogue record

Date deposited: 07 Aug 2008
Last modified: 17 Jul 2017 14:30

Export record

Altmetrics

Contributors

Author: G.R. Christie
Author: E. Hajduch
Author: H.S. Hundal
Author: C.G. Proud
Author: P.M. Taylor

University divisions

Download statistics

Downloads from ePrints over the past year. Other digital versions may also be available to download e.g. from the publisher's website.

View more statistics

Atom RSS 1.0 RSS 2.0

Contact ePrints Soton: eprints@soton.ac.uk

ePrints Soton supports OAI 2.0 with a base URL of http://eprints.soton.ac.uk/cgi/oai2

This repository has been built using EPrints software, developed at the University of Southampton, but available to everyone to use.

We use cookies to ensure that we give you the best experience on our website. If you continue without changing your settings, we will assume that you are happy to receive cookies on the University of Southampton website.

×