Related Experiment Video
Updated: Jun 25, 2026

A Human Blood-Brain Interface Model to Study Barrier Crossings by Pathogens or Medicines and Their Interactions with the Brain
Published on: April 9, 2019
A TAG on to the neurogenic functions of APP
Quan-Hong Ma1, Dominique Bagnard, Zhi-Cheng Xiao
1Institute of Molecular and Cell Biology, Singapore.
Abstract:
The proteolytic processing of amyloid beta precursor protein (APP) has long been studied because of its association with the pathology of Alzheimer's disease (AD). The ectodomain of APP is shed by alpha- or beta-secretase cleavage. The remaining membrane bound stub can then undergo regulated intramembrane proteolysis (RIP) by gamma-secretase. This cleavage can release amyloid beta (Abeta) from the stub left by beta-secretase cleavage but also releases the APP intracellular domain (AICD) after alpha- or beta-secretase cleavage. The physiological functions of this proteolytic processing are not well understood. We compare the proteolytic processing of APP to the ligand-dependent RIP of Notch. In this review, we discuss recent evidence suggesting that TAG1 is a functional ligand for APP. The interaction between TAG1 and APP triggers gamma-secretase-dependent release of AICD. TAG1, APP and Fe65 colocalise in the neurogenic ventricular zone and in fetal neural progenitor cells in vitro. Experiments in TAG1, APP and Fe65 null mice as well as TAG1 and APP double-null mice demonstrate that TAG1 induces a gamma-secretase- and Fe65-dependent suppression of neurogenesis.
Related Concept Videos
Neuroplasticity
Neural Regulation
Neurons as Communicators of the Brain
Cell Body
The cell body, also known...
Integration of Synaptic Events
Functions of the Nervous System
Neurogenesis and Regeneration of Nervous Tissue

