Maturation and pro-peptide cleavage of β-secretase
J Biol Chem 275(40): 30849-54
| Authors/Editors: |
Capell A Steiner H Willem M Kaiser H Meyer C Walter J Lammich S Multhaup G Haass C |
|---|---|
| Publication Date: | 2000 |
| Type of Publication: | Journal Article |
Amyloid β-peptide is generated by two sequential proteolytic cleavages mediated by β-secretase (BACE) and γ-secretase. BACE was recently identified as a membrane-associated aspartyl protease. We have now analyzed the maturation and pro-peptide cleavage of BACE. Pulse-chase experiments revealed that BACE is post-translationally modified during transport to the cell surface, which can be monitored by a significant increase in the molecular mass. The increase in molecular mass is caused by complex N-glycosylation. Treatment with tunicamycin and N-glycosidase F led to a BACE derivative with a molecular weight corresponding to an unmodified version. In contrast, the mature form of BACE was resistant to endoglycosidase H treatment. The cytoplasmic tail of BACE was required for efficient maturation and trafficking through the Golgi; a BACE variant lacking the cytoplasmic tail undergoes inefficient maturation. In contrast a soluble BACE variant that does not contain a membrane anchor matured more rapidly than full-length BACE. Pro-BACE was predominantly located within the endoplasmic reticulum. Pro-peptide cleavage occurred immediately before full maturation and trafficking through the Golgi.
