A presenilin-1-dependent γ-secretase-like protease mediates release of Notch intracellular domain

Abstract

Signalling through the receptor protein Notch, which is involved in crucial cell-fate decisions during development, requires ligand-induced cleavage of Notch. This cleavage occurs within the predicted transmembrane domain, releasing the Notch intracellular domain (NICD), and is reminiscent of gamma-secretase-mediated cleavage of beta-amyloid precursor protein (APP), a critical event in the pathogenesis of Alzheimer's disease. A deficiency in presenilin-1 (PS1) inhibits processing of APP by gamma-secretase in mammalian cells, and genetic interactions between Notch and PS1 homologues in Caenorhabditis elegans indicate that the presenilins may modulate the Notch signalling pathway. Here we report that, in mammalian cells, PS1 deficiency also reduces the proteolytic release of NICD from a truncated Notch construct, thus identifying the specific biochemical step of the Notch signalling pathway that is affected by PS1. Moreover, several gamma-secretase inhibitors block this same step in Notch processing, indicating that related protease activities are responsible for cleavage within the predicted transmembrane domains of Notch and APP. Thus the targeting of gamma-secretase for the treatment of Alzheimer's disease may risk toxicity caused by reduced Notch signalling.

Identification of a novel NOTCH-4/INT-3 RNA species encoding an activated gene product in certain human tumor cell lines

“…As shown in Figure 5b (lanes 2 ± 6), multiple bands were detected in protein extracts of the di erent cell lines. The multiple bands observed in Figure 5b undoubledly re¯ect, in part, the previously noted complex array of proteolytic cleavage products that accumulate during maturation of NOTCH proteins De Strooper et al, 1999;Hardy et al, 1999;Logeat et al, 1998;Struhl et al, 1999;Ye et al, 1999). The speci®city of this reactivity was demonstrated by the ability of the immunogenic peptide to block the reaction (Figure 5c).…”

Membrane immersion allows rhomboid proteases to achieve specificity by reading transmembrane segment dynamics

“…Even more remarkable is the broad array of cellular networks that intramembrane proteases have come to regulate. Intensively studied is γ-secretase, an aspartyl intramembrane protease that releases signaling domains from the membrane, including the intracellular domains of the Notch receptor and the amyloid-β precursor protein (APP) implicated in Alzheimer's disease (De Strooper et al, 1998, 1999; Wolfe et al, 1999). Homologous signal peptide peptidases function in immunity by liberating signaling domains of TNFα and FasL (Fluhrer et al, 2006; Friedmann et al, 2006; Kirkin et al, 2007).…”

Cathepsin D is partly endocytosed by the LRP1 receptor and inhibits LRP1-regulated intramembrane proteolysis

“…More recent studies have shown that LRP1 influences gene transcription by regulated intramembrane proteolysis (RIP) of its b-chain (May et al, 2002;Kinoshita et al, 2003;von Arnim et al, 2005;Zurhove et al, 2008). RIP is a process that involves two cleavages, as described for Notch (De Strooper et al, 1999), APP (amyloid precursor protein) (De Strooper et al, 1998) andLRP6 (Mi andJohnson, 2007). The first cleavage, performed by metalloproteinases (Quinn et al, 1999;Rozanov et al, 2004;Liu et al, 2009;Selvais et al, 2009Selvais et al, , 2011 and by the membrane-associated b-secretase, BACE1 (von Arnim et al, 2005), occurs in the extracellular region, close to the plasma membrane, and leads to shedding of the LRP1b ectodomain.…”