The 42-residue amyloid beta protein (Aβ42) has been shown to be toxic to neurons and is believed to play a key causative role in Alzheimer's disease (AD). A search for Aβ binding proteins that can mediate its toxicity resulted in the identification of the endoplasmic-reticulum (ER) associated Aβ binding protein (ERAB) which was also shown to be involved in Aβ induced apoptosis. The primary report indicated that a signal sequence is absent in ERAB suggesting that it is bound to the cytoplasmic aspect of cellular membranes. Aβ is generated in the lumen of secretory organelles and released into the medium resulting in its separation from ERAB by a membrane barrier. After computer analysis of the ERAB sequence, we have detected a putative signal peptide that can direct the protein into the secretory pathway. This signal sequence was found in human, rodent, and bovine ERAB suggesting that it is a type II integral membrane protein in vertebrates. This topology can explain the binding of Aβ to ERAB. Our finding that an integral membrane form of ERAB can bind to Aβ in the lumen of transport vesicles and other cytoplasmic receptors provides a basis for understanding its role in AD.
|Original language||English (US)|
|Number of pages||4|
|Journal||Biochemical and Biophysical Research Communications|
|State||Published - Aug 19 1998|
ASJC Scopus subject areas
- Molecular Biology
- Cell Biology