Checks And Balances

摘要

During embryonic development, nerve cells are made in excess numbers, and many of these neurons and their long extensions (axons) are then culled in a phase of natural degeneration. Nikolaev et al. now identify the apoptosis-inducing protein DR6 (death receptor 6) as a regulator of this process, acting by binding to APP (β-amyloid precursor protein), a trans-membrane protein of unknown function that has been implicated in Alzheimer's disease through human genetics. Unlike classical neu-ronal apoptosis, which requires caspase 3, DR6/APP-induced degeneration requires caspase 6 activation. This work suggests that an extracellular fragment of APP, acting via DR6 and caspase 6, may contribute to neural degeneration in Alzheimer's disease.