Notch1 Autoactivation via Transcriptional Regulation of Furin, Which Sustains Notch1 Signaling by Processing Notch1-Activating Proteases ADAM10 and Membrane Type 1 Matrix Metalloproteinase.
Notch1 is an evolutionarily conserved transmembrane receptor involved in melanoma growth. Notch1 is first cleaved by furin in the Golgi apparatus to produce the biologically active heterodimer. Following ligand binding, Notch1 is cleaved at the cell membrane by proteases such as ADAM10 and -17 and membrane type 1 matrix metalloproteinase (MT1-MMP), the latter of which we recently identified as a novel protease involved in Notch1 processing. The final cleavage is γ-secretase dependent and releases the active Notch intracellular domain (NIC). We now demonstrate that Notch1 directly regulates furin expression. Aside from activating Notch1, furin cleaves and activates several proteases, including MT1-MMP, ADAM10, and ADAM17. By chromatin immunoprecipitation and a reporter assay, we demonstrate that Notch1 binds at position -1236 of the furin promoter and drives furin expression. The Notch1-dependent enhancement of furin expression increases the activities of MT1-MMP and ADAM10 but not that of ADAM17, as demonstrated by short hairpin RNA (shRNA) knockdown of furin, and promotes the cleavage of Notch1 itself. These data highlight a novel positive-feedback loop whereby Notch1-dependent furin expression can induce Notch1 signaling by increasing Notch1 processing and by potentiating the activity of the proteases responsible for Notch1 activation. This leads to Notch1 signal amplification, which can promote melanoma tumor growth and progression, as demonstrated by the inhibition of cell migration and invasion upon furin inhibition downstream of Notch1. Disruption of such feedback signaling might represent an avenue for the treatment of melanoma.
Department of Biochemistry, Case Western Reserve University School of Medicine, Cleveland, Ohio, USA.
Hong
H
Qiu
Department of Biochemistry, Case Western Reserve University School of Medicine, Cleveland, Ohio, USA.
Xiaoying
X
Tang
Department of Biochemistry, Case Western Reserve University School of Medicine, Cleveland, Ohio, USA.
Jun
J
Ma
Department of Biochemistry, Case Western Reserve University School of Medicine, Cleveland, Ohio, USA.
Khvaramze
K
Shaverdashvili
Department of Biochemistry, Case Western Reserve University School of Medicine, Cleveland, Ohio, USA.
Keman
K
Zhang
Department of Biochemistry, Case Western Reserve University School of Medicine, Cleveland, Ohio, USA bxb278@case.edu.
Barbara
B
Bedogni
D051722:ADAM Proteins / Q000378:metabolism*; D000072197:ADAM10 Protein; D000072198:ADAM17 Protein; D053829:Amyloid Precursor Protein Secretases / Q000378:metabolism*; D045744:Cell Line, Tumor; D002465:Cell Movement; D004789:Enzyme Activation; D045683:Furin / Q000235:genetics* / Q000378:metabolism; D006801:Humans; D053511:Matrix Metalloproteinase 14 / Q000378:metabolism*; D008545:Melanoma / Q000235:genetics / Q000378:metabolism / Q000473:pathology; D008565:Membrane Proteins / Q000378:metabolism*; D009361:Neoplasm Invasiveness / Q000235:genetics / Q000473:pathology; D011401:Promoter Regions, Genetic; D051881:Receptor, Notch1 / Q000378:metabolism*; D015398:Signal Transduction; D015533:Transcriptional Activation
D008565:Membrane Proteins; C497761:NOTCH1 protein, human; D051881:Receptor, Notch1; D053829:Amyloid Precursor Protein Secretases; D045683:Furin; D051722:ADAM Proteins; C507086:MMP14 protein, human; D053511:Matrix Metalloproteinase 14; D000072197:ADAM10 Protein; C491236:ADAM10 protein, human; D000072198:ADAM17 Protein; C000606462:ADAM17 protein, human