QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

Vol. 19, Issue 10, 4086-4098, October 2008

This Article Full Text Full Text (PDF) All Versions of this Article: E08-05-0459v1 19/10/4086    most recent Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Vanoni, O. Articles by Molinari, M. Search for Related Content PubMed PubMed Citation Articles by Vanoni, O. Articles by Molinari, M.

Consequences of Individual N-glycan Deletions and of Proteasomal Inhibition on Secretion of Active BACE

Omar Vanoni^*, Paolo Paganetti, and Maurizio Molinari^*

*Institute for Research in Biomedicine, CH-6500 Bellinzona, Switzerland; and Novartis Institutes for Biomedical Research Basel, Neuroscience Research, Novartis Pharma AG, CH-4002 Basel, Switzerland

Submitted May 6, 2008; Revised July 3, 2008; Accepted July 8, 2008
Monitoring Editor: Reid Gilmore

BACE is an aspartic protease involved in the production of a toxic peptide accumulating in the brain of Alzheimer's disease patients. After attainment of the native structure in the endoplasmic reticulum (ER), BACE is released into the secretory pathway. To better understand the mechanisms regulating protein biogenesis in the mammalian ER, we determined the fate of five variants of soluble BACE with 4, 3, 2, 1, or 0 N-linked glycans. The number of N-glycans displayed on BACE correlated directly with folding and secretion rates and with the yield of active BACE harvested from the cell culture media. Addition of a single N-glycan was sufficient to recruit the calnexin chaperone system and/or for oligosaccharide de-glucosylation by the ER-resident -glucosidase II. Addition of 1–4 N-glycans progressively enhanced the dissociation rate from BiP and reduced the propensity of newly synthesized BACE to enter aberrant soluble and insoluble aggregates. Finally, inhibition of the proteasome increased the yield of active BACE. This shows that active protein normally targeted for destruction can be diverted for secretion, as if for BACE the quality control system would be acting too stringently in the ER lumen, thus causing loss of functional polypeptides.

Address correspondence to: Maurizio Molinari (maurizio.molinari{at}irb.unisi.ch)

Abbreviations used: BACE, Beta-site APP-cleaving enzyme 1; BACEs, soluble form of BACE; bDNJ, N-butyl-deoxynojirimycin; CHO, Chinese hamster ovary cells; DBA, disulfide-bonded aggregates; EndoH, endoglycosidase H; ER, endoplasmic reticulum; ERAD, ER-associated degradation; HEK, human embryonic kidney cells.

This article has been cited by other articles:

				R. Bernasconi, C. Galli, V. Calanca, T. Nakajima, and M. Molinari Stringent requirement for HRD1, SEL1L, and OS-9/XTP3-B for disposal of ERAD-LS substrates J. Cell Biol., January 25, 2010; 188(2): 223 - 235. [Abstract] [Full Text] [PDF]

				K. Noma, K. Kimura, K. Minatohara, H. Nakashima, Y. Nagao, A. Mizoguchi, and Y. Fujiyoshi Triple N-Glycosylation in the Long S5-P Loop Regulates the Activation and Trafficking of the Kv12.2 Potassium Channel J. Biol. Chem., November 27, 2009; 284(48): 33139 - 33150. [Abstract] [Full Text] [PDF]

				T. Watanabe, K. Totani, I. Matsuo, J.-i. Maruyama, K. Kitamoto, and Y. Ito Genetic analysis of glucosidase II {beta}-subunit in trimming of high-mannose-type glycans Glycobiology, August 1, 2009; 19(8): 834 - 840. [Abstract] [Full Text] [PDF]