The University of Southampton
University of Southampton Institutional Repository

Inhibition of alpha-glucosidases I and II increases the cell surface expression of functional class A macrophage scavenger receptor (SR-A) by extending its half-life

Tian, G., Wilcockson, D., Perry, V.H., Rudd, P.M., Dwek, R.A., Platt, F.M. and Platt, N. (2004) Inhibition of alpha-glucosidases I and II increases the cell surface expression of functional class A macrophage scavenger receptor (SR-A) by extending its half-life The Journal of Biological Chemistry, 279, (38), pp. 39303-39309. (doi:10.1074/jbc.M405219200).

Record type: Article


The class A scavenger receptor (SR-A) is a multifunctional trimeric membrane glycoprotein involved in atherogenesis. The mature receptor can mediate the binding and internalization of a number of specific ligands, including modified low-density lipoprotein. We have investigated the effects of inhibiting N-glycan processing on SR-A expression, distribution, and activity in the murine macrophage cell line RAW264.7. We have found that SR-A normally interacts with calnexin in the endoplasmic reticulum and in its mature form carries complex N-glycans. The imino sugar, N-butyldeoxynojirimycin (NB-DNJ) is an inhibitor of the N-glycan processing enzymes -glucosidases I and II. Following NB-DNJ treatment SR-A became Endo H-sensitive, consistent with inhibition of N-glycan processing. A dose-dependent increase in cell surface expression of SR-A was observed in response to NB-DNJ treatment. The receptor on inhibitor-treated cells was still functional because the increased surface expression resulted in a proportional enhancement in the endocytosis of the ligand, acetylated low-density lipoprotein. The expression of SR-A on NB-DNJ cultured cells was further enhanced by co-treatment with interferon-. Quantitative reverse transcriptase-PCR analysis did not show a significant difference in the amount of SR-A mRNA in NB-DNJ-treated RAW264.7 cells. However, the half-life of SR-A protein was significantly increased. These data indicate the retention of glucosylated N-glycans does not result in gross misfolding and degradation of this receptor or prevent its transport to the cell surface. SR-A interacts with calnexin and when the association is prevented changes in the recycling kinetics and rate of turnover of the receptor result, leading to enhanced cell surface expression.

PDF Tian_et_al.pdf - Version of Record
Restricted to Registered users only
Download (227kB)

More information

Published date: 2004


Local EPrints ID: 41141
ISSN: 0021-9258
PURE UUID: 121bdce0-8682-438f-bd86-ee99dceebaa9

Catalogue record

Date deposited: 21 Jul 2006
Last modified: 17 Jul 2017 15:32

Export record



Author: G. Tian
Author: D. Wilcockson
Author: V.H. Perry
Author: P.M. Rudd
Author: R.A. Dwek
Author: F.M. Platt
Author: N. Platt

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 supports OAI 2.0 with a base URL of

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.