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Updated: Jan 20, 2026
Peptide-based Identification of Functional Motifs and their Binding Partners
Published on: June 30, 2013
Mutagenesis of the ADAM17-phosphatidylserine-binding motif leads to embryonic lethality in mice
Martin Veit1, Björn Ahrens1, Jana Seidel1
1Department of Dermatology, University of Kiel, Kiel, Germany.
Abstract:
ADAM17, prominent member of the "Disintegrin and Metalloproteinase" (ADAM) family, controls vital cellular functions through cleavage of transmembrane substrates. Several of these play central roles in oncogenesis and inflammation, yet despite its importance, the mechanism by which ADAM17 is activated is not fully understood. We recently presented evidence that surface exposure of phosphatidylserine (PS) is the penultimate event required for sheddase activation, which occurs upon binding of a membrane-proximal, cationic binding motif to the anionic phospholipid headgroup. Here, we show that mutagenesis of the 3 amino acids constituting the PS-binding motif leads to embryonic lethality in mice. Heterozygotes showed no abnormalities. Primary hepatocytes and fibroblasts were analysed and found to express the mutant protease on the cell surface. However, PMA-stimulated release of ADAM17 substrates was completely abolished. The results directly support the novel concept of transiently externalised PS as essential trigger of extracellular protease function in vivo.
Insights
Phosphatidylserine (PS) exposure is crucial for activating the ADAM17 protease. Mutating its binding site causes embryonic lethality, confirming PS
Area of Science:
- Biochemistry
- Molecular Biology
- Cellular Biology
Background:
- ADAM17 (A Disintegrin and Metalloproteinase domain) is a key protease regulating cellular functions via substrate cleavage.
- Its substrates are implicated in oncogenesis and inflammation, but ADAM17 activation mechanisms remain unclear.
- Previous work suggested phosphatidylserine (PS) exposure is vital for ADAM17 activation.
Purpose of the Study:
- To investigate the in vivo role of the phosphatidylserine (PS)-binding motif in ADAM17 activation.
- To determine the functional consequences of disrupting PS binding for ADAM17 activity.
Main Methods:
- Generation and analysis of mice with mutated ADAM17 PS-binding motifs.
- Assessment of ADAM17 expression and substrate release in primary cells (hepatocytes, fibroblasts).
- Utilized phorbol 12-myristate 13-acetate (PMA) stimulation to assess protease activity.
Main Results:
- Mutagenesis of the PS-binding motif resulted in embryonic lethality in mice.
- Heterozygous mice showed normal development but lacked PMA-stimulated ADAM17 substrate release.
- Mutant ADAM17 was expressed on the cell surface, but its sheddase activity was abolished.
Conclusions:
- Transiently externalized phosphatidylserine (PS) is essential for triggering extracellular protease function in vivo.
- The PS-binding motif of ADAM17 is critical for its activation and physiological function.
- Disruption of PS binding by ADAM17 has severe developmental consequences.
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