Endocytosis of synaptic ADAM10 in neuronal plasticity and Alzheimer’s disease
Elena Marcello, … , Fabrizio Gardoni, Monica Di Luca
Elena Marcello, … , Fabrizio Gardoni, Monica Di Luca
Published May 8, 2013
Citation Information: J Clin Invest. 2013;123(6):2523-2538. https://doi.org/10.1172/JCI65401.
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Research Article Neuroscience

Endocytosis of synaptic ADAM10 in neuronal plasticity and Alzheimer’s disease

Abstract

A disintegrin and metalloproteinase 10 (ADAM10), a disintegrin and metalloproteinase that resides in the postsynaptic densities (PSDs) of excitatory synapses, has previously been shown to limit β-amyloid peptide (Aβ) formation in Alzheimer’s disease (AD). ADAM10 also plays a critical role in regulating functional membrane proteins at the synapse. Using human hippocampal homogenates, we found that ADAM10 removal from the plasma membrane was mediated by clathrin-dependent endocytosis. Additionally, we identified the clathrin adaptor AP2 as an interacting partner of a previously uncharacterized atypical binding motif in the ADAM10 C-terminal domain. This domain was required for ADAM10 endocytosis and modulation of its plasma membrane levels. We found that the ADAM10/AP2 association was increased in the hippocampi of AD patients compared with healthy controls. Long-term potentiation (LTP) in hippocampal neuronal cultures induced ADAM10 endocytosis through AP2 association and decreased surface ADAM10 levels and activity. Conversely, long-term depression (LTD) promoted ADAM10 synaptic membrane insertion and stimulated its activity. ADAM10 interaction with the synapse-associated protein-97 (SAP97) was necessary for LTD-induced ADAM10 trafficking and required for LTD maintenance and LTD-induced changes in spine morphogenesis. These data identify and characterize a mechanism controlling ADAM10 localization and activity at excitatory synapses that is relevant to AD pathogenesis.

Authors

Elena Marcello, Claudia Saraceno, Stefano Musardo, Hugo Vara, Alerie Guzman de la Fuente, Silvia Pelucchi, Daniele Di Marino, Barbara Borroni, Anna Tramontano, Isabel Pérez-Otaño, Alessandro Padovani, Maurizio Giustetto, Fabrizio Gardoni, Monica Di Luca

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Figure 1

ADAM10 interacts with the clathrin adaptor AP2, and this association is increased in AD patients’ hippocampus.

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ADAM10 interacts with the clathrin adaptor AP2, and this association is ...
(A) Human hippocampus homogenate IP with a rabbit anti-ADAM10 antibody. WB analysis revealed the presence of AP2 subunits, α-adaptin, β2-adaptin, and μ2 subunit, but not of the AP1 subunit γ-adaptin, in the immunocomplex. IP ADAM10 was detected by WB with a rat anti-ADAM10 antibody. As shown in the right lanes, no signal is detectable when the sample is precipitated without ADAM10 antibody. Lanes were run on the same gel but were not contiguous. (B) Homogenates from hippocampi of 6 HC and 6 AD patients were IP with anti-ADAM10 antibody and AP2 subunits coprecipitation evaluated. ADAM10/AP2 association is increased in AD compared with HC. γ-adaptin does not precipitate with ADAM10 in both groups. The levels of IP ADAM10 were detected by WB with a rat anti-ADAM10 antibody. Left lanes show WB performed on total homogenate from HC and AD hippocampi. No alterations of α-adaptin, β2-adaptin, μ2 subunit, γ-adaptin, and ADAM10 levels were detected. (C) OD was measured. Quantification of IP experiments in B (*P < 0.05, AD versus HC [C], n = 12). (D) Quantification of total levels of α-adaptin, β2-adaptin, μ2 subunit, shown in B (P < 0.05, AD versus HC, n = 12). All data were normalized on tubulin OD. In this and all subsequent figures, data represent mean ± SEM.