Structural Basis for Regulated Proteolysis by the α-Secretase ADAM10

• Published in: Cell Vol. 171; no. 7; pp. 1638 - 1648.e7
• Main Authors: Seegar, Tom C.M., Killingsworth, Lauren B., Saha, Nayanendu, Meyer, Peter A., Patra, Dhabaleswar, Zimmerman, Brandon, Janes, Peter W., Rubinstein, Eric, Nikolov, Dimitar B., Skiniotis, Georgios, Kruse, Andrew C., Blacklow, Stephen C.
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 14.12.2017; Elsevier
• Subjects: ADAM10; ADAM10 Protein - chemistry; ADAM10 Protein - metabolism; amyloid precursor protein; Amyloid Precursor Protein Secretases - chemistry; Amyloid Precursor Protein Secretases - metabolism; Crystallography, X-Ray; Humans; Life Sciences; Membrane Proteins - chemistry; Membrane Proteins - metabolism; Models, Molecular; Notch signaling; Proteolysis; Receptors, Notch - metabolism; Signal Transduction; X-ray crystallography; X-ray crystallography; ADAM10; amyloid precursor protein; Notch signaling
• ISSN: 0092-8674; 1097-4172
• DOI: 10.1016/j.cell.2017.11.014

Cleavage of membrane-anchored proteins by ADAM (a disintegrin and metalloproteinase) endopeptidases plays a key role in a wide variety of biological signal transduction and protein turnover processes. Among ADAM family members, ADAM10 stands out as particularly important because it is both responsible for regulated proteolysis of Notch receptors and catalyzes the non-amyloidogenic α-secretase cleavage of the Alzheimer’s precursor protein (APP). We present here the X-ray crystal structure of the ADAM10 ectodomain, which, together with biochemical and cellular studies, reveals how access to the enzyme active site is regulated. The enzyme adopts an unanticipated architecture in which the C-terminal cysteine-rich domain partially occludes the enzyme active site, preventing unfettered substrate access. Binding of a modulatory antibody to the cysteine-rich domain liberates the catalytic domain from autoinhibition, enhancing enzymatic activity toward a peptide substrate. Together, these studies reveal a mechanism for regulation of ADAM activity and offer a roadmap for its modulation. [Display omitted] •We report an X-ray structure of the ectodomain of the α-secretase ADAM10•Access to the active site is partially occluded by a C-terminal regulatory domain•A modulatory antibody that binds the regulatory region liberates the active site•Catalytically inactive forms of ADAM10 exhibit dominant-negative activity The X-ray structure of the ADAM10 ectodomain, together with biochemical and cell-based studies, reveals mechanistic insights into its enzymatic function in Notch signaling and in processing of the Alzheimer's precursor protein APP.