BRI2 interacts with BACE1 and regulates its cellular levels by promoting its degradation and reducing its mRNA levels.

BRI2, a protein mutated in Familial British and Familial Danish Dementias, interacts with Amyloid Precursor Protein (APP) and reduces the levels of secreted APPβ (sAPPβ), which derives from APP cleavage by β-secretase (BACE1). Exploring the mechanisms of this effect, we obtained data that BRI2 decreases the cellular levels of BACE1 thus reducing the β-cleavage of APP. Deletion of N-terminal cytoplasmic or C-terminal extracellular sequences of BRI2 neither affected its interaction with BACE1 or APP (Fotinopoulou et al.

Downregulation of AβPP enhances both calcium content of endoplasmic reticulum and acidic stores and the dynamics of store operated calcium channel activity.

The amyloid-β protein precursor (AβPP) is a type-1 transmembrane protein involved in Alzheimer's disease (AD). It has become increasingly evident that AβPP, its protein-protein interactions, and its proteolytical fragments may affect calcium homeostasis and vice versa. In addition, there is evidence that calcium dysregulation contributes to AD.

Presenilin 1 and cadherins: stabilization of cell-cell adhesion and proteolysis-dependent regulation of transcription.

Presenilin-1 (PS1) has gained intensive attention in relation to Alzheimer's disease, since it has been shown that PS1 mutations are linked to familial Alzheimer's disease (FAD), and that PS1 is a member of the high molecular weight complex of gamma-secretase, which generates the carboxyl end of beta-amyloid peptide (gamma-cleavage). A parallel line of evidence suggests that upon formation of cell-cell contacts, presenilin colocalizes with cadherins at the cell surface and stabilizes the cadherin-based adhesion complex. Under conditions stimulating cell-cell dissociation, cadherins are processed by a PS1/gamma-secretase activity, promoting disassembly of adherens junctions, and resulting in the increase of cytosolic beta-catenin, which is an important regulator of the Wnt/Wingless signaling pathway.

BRI2 interacts with amyloid precursor protein (APP) and regulates amyloid beta (Abeta) production.

Transmembrane proteins BRI2 and amyloid precursor protein (APP) co-localize with amyloid beta (Abeta) lesions in sporadic Alzheimer disease and mutations in both precursor proteins are linked to early-onset familial cases of cerebral amyloidosis associated with dementia and/or cerebral hemorrhage. A specific interaction between BRI2 and APP was unveiled by immunoprecipitation experiments using transfected and non-transfected cells. The use of deletion mutants further revealed that stretches 648-719 of APP751 and 46-106 of BRI2, both inclusive of the full transmembrane domains, are sufficient for the interaction.

Screening for glycosylation changes on recombinant human IgG using lectin methods.

Two lectin-binding methods were investigated as possible ways of monitoring the glycosylation of human monoclonal antibodies during their development and production. Carbohydrate composition was assessed in various preparations that were produced in different host cell types, cell sublines or batches of the same cells. The lectin binding was measured with ELISA and surface plasmon resonance (SPR).