beta-Amyloid protein converting enzyme 1 and brain-specific type II membrane protein BRI: binding partners processed by furin.

摘要

Abstract Using a yeast two-hybrid system, we screened a human brain cDNA library for possible interacting proteins with the C-terminal cytosolic tail of the beta-secretase beta-amyloid protein converting enzyme (BACE)1. This identified seven potential candidates, including the brain-specific type II membrane protein BRI(3). Co-localization and co-immunoprecipitation experiments confirmed that BACE1 and BRI(3) co-localize and interact with each other via the cytosolic tail of BACE1. Furthermore, pulse and pulse-chase analyses revealed that the pro-protein convertases furin, and to a lesser extent PC7 and PC5A, process BRI(3) into a C-terminal secreted approximately 4-kDa product. Thus, furin efficiently processes both pro-BACE1 and its novel interacting protein pro-BRI(3).