edoc

pH-induced conversion of the transport lectin ERGIC-53 triggers glycoprotein release

Appenzeller-Herzog, C. and Roche, A. -C. and Nufer, O. and Hauri, H. -P.. (2004) pH-induced conversion of the transport lectin ERGIC-53 triggers glycoprotein release. Journal of Biological Chemistry, Vol. 279, H. 13. pp. 12943-12950.

Full text not available from this repository.

Official URL: http://edoc.unibas.ch/dok/A5257752

Downloads: Statistics Overview

Abstract

The recycling mannose lectin ERGIC-53 operates as a transport receptor by mediating efficient endoplasmic reticulum (ER) export of some secretory glycoproteins. Binding of cargo to ERGIC-53 in the ER requires Ca2+. Cargo release occurs in the ERGIC, but the molecular mechanism is unknown. Here we report efficient binding of purified ERGIC-53 to immobilized mannose at pH 7.4, the pH of the ER, but not at slightly lower pH. pH sensitivity of the lectin was more prominent when Ca2+ concentrations were low. A conserved histidine in the center of the carbohydrate recognition domain was required for lectin activity suggesting it may serve as a molecular pH/Ca2+ sensor. Acidification of cells inhibited the association of ERGIC-53 with the known cargo cathepsin Z-related protein and dissociation of this glycoprotein in the ERGIC was impaired by organelle neutralization that did not impair the transport of a control protein. The results elucidate the molecular mechanism underlying reversible lectin/cargo interaction and establish the ERGIC as the earliest low pH site of the secretory pathway.
Faculties and Departments:05 Faculty of Science > Departement Biozentrum > Former Organization Units Biozentrum > Pharmacology/Neurobiology (Hauri)
UniBasel Contributors:Hauri, Hans-Peter
Item Type:Article, refereed
Article Subtype:Research Article
Bibsysno:Link to catalogue
Publisher:American Society of Biological Chemists
ISSN:0021-9258
Note:Publication type according to Uni Basel Research Database: Journal article
Last Modified:22 Mar 2012 14:20
Deposited On:22 Mar 2012 13:18

Repository Staff Only: item control page