Tetraspanin12 regulates ADAM10-dependent cleavage of amyloid precursor protein. FASEB J

Dana-Farber Cancer Institute and Department of Pathology, Harvard Medical School, Boston, Massachusetts 02115, USA.
The FASEB Journal (Impact Factor: 5.04). 08/2009; 23(11):3674-81. DOI: 10.1096/fj.09-133462
Source: PubMed


Using mass spectrometry, we identified ADAM10 (a membrane-associated metalloproteinase) as a partner for TSPAN12, a tetraspanin protein. TSPAN12-ADAM10 interaction was confirmed by reciprocal coimmunoprecipitation in multiple tumor cell lines. TSPAN12, to a greater extent than other tetraspanins (CD81, CD151, CD9, and CD82), associated with ADAM10 but not with ADAM17. Overexpression of TSPAN12 enhanced ADAM10-dependent shedding of amyloid precursor protein (APP) in MCF7 (breast cancer) and SH-SY5Y (neuroblastoma) cell lines. Conversely, siRNA ablation of endogenous TSPAN12 markedly diminished APP proteolysis in both cell lines. Furthermore, TSPAN12 overexpression enhanced ADAM10 prodomain maturation, whereas TSPAN12 ablation diminished ADAM10 maturation. A palmitoylation-deficient TSPAN12 mutant failed to associate with ADAM10, inhibited ADAM10-dependent proteolysis of APP, and inhibited ADAM10 maturation, most likely by interfering with endogenous wild-type TSPAN12. In conclusion, TSPAN12 serves as a novel and robust partner for ADAM10 and promotes ADAM10 maturation, thereby facilitating ADAM10-dependent proteolysis of APP. This novel mode of regulating APP cleavage is of relevance to Alzheimer's disease therapy.

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    • "All three of these genes contribute to the production of Aβ [1]. As mentioned previously, miR146a may play a role in the production of Aβ through the miR146a-TSPAN12-ADAM10 (α-secretase) pathway [25], [26] (Figure S1). We hypothesized that in addition to the regulating role of miR146a polymorphisms on the neuroinflammation, rs57095329 may also influence the metabolism of APP and eventually increase the generation of Aβ42, thus contributing to the risk of EOAD. "
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    ABSTRACT: miR146a is well known for its regulatory role in the immune response and inflammation. Recent studies have demonstrated the links between miR146a and Alzheimer disease (AD) and suggested that miR146a may be involved in neuroinflammation and the metabolism of amyloid-β (Aβ), which are critical events in AD pathology. Although genetic studies have focused on the association between the miR146a gene and susceptibility to several diseases, no association study of miR146a variability with AD has been conducted. In this report, we performed a case-control association study to analyze the genotype and allele distributions of the miR146a, rs2910464 and rs57095329 polymorphisms in a Chinese population consisting of 292 AD cases and 300 healthy controls. We found a significant difference in the genotypes and allele frequencies of rs57095329 between the AD cases and the controls (p = 0.0147 and p = 0.0184, respectively), where the AA genotype of rs57095329 was associated with an increased risk of AD as well the cognitive decline in AD patients. Additionally, the AA genotype of rs57095329 exhibited significantly higher miR146a expression than the GG+GA genotypes of rs2910164 in the peripheral blood cells (PBMCs) of healthy individuals and had a stronger effect on the production of IL-6 and IL-1β when the cells were stimulated with LPS. Our data provide preliminary evidence that the rs57095329 polymorphism in the miR146a promoter is involved in the genetic susceptibility to AD, and this risk AA genotype may increase the expression of miR146a and influence certain proinflammatory cytokines, thus playing a role in the pathogenesis of AD.
    Full-text · Article · Feb 2014 · PLoS ONE
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    • "Interestingly, also the reported association of ADAM10 and ADAM17 with repositioning and activity promoting tetraspanins seems to differ between the two proteases. Whereas ADAM10 interacts with several members of the conserved TspanC8 subfamily (Tspan5, Tspan10, Tspan14, Tspan15, Tspan17, and Tspan33) and Tspan12 [61–63], ADAM17 was shown to interact primarily with CD9 [64]. Notably, over the past years, this PKC issue has been rather controversially discussed: A number of reports indicated that PKC and/or growth factor stimulation result in an ERK-dependent phosphorylation of the intracellular part of ADAM17 [38,65–67]. "
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    ABSTRACT: A disintegrin and metalloproteases (ADAMs) have been implicated in many processes controlling organismic development and integrity. Important substrates of ADAM proteases include growth factors, cytokines and their receptors and adhesion proteins. The inducible but irreversible cleavage of their substrates alters cell-cell communication and signaling. The crucial role of ADAM proteases (e.g. ADAM10 and 17) for mammalian development became evident from respective knockout mice, that displayed pre- or perinatal lethality with severe defects in many organs and tissues. Although many substrates for these two ADAM proteases were identified over the last decade, the regulation of their surface appearance, their enzymatic activity and their substrate specificity are still not well understood. We therefore analyzed the constitutive and inducible surface expression of ADAM10 and ADAM17 on a variety of human T cell and tumor cell lines. We demonstrate that ADAM10 is constitutively present at comparably high levels on the majority of the tested cell types. Stimulation with phorbol ester and calcium ionophore does not significantly alter the amount of surface ADAM10, except for a slight down-regulation from T cell blasts. Using FasL shedding as a readout for ADAM10 activity, we show that PKC activation and calcium mobilization are both prerequisite for activation of ADAM10 resulting in a production of soluble FasL. In contrast to ADAM10, the close relative ADAM17 is detected at only low levels on unstimulated cells. ADAM17 surface expression on T cell blasts is rapidly induced by stimulation. Since this inducible mobilization of ADAM17 is sensitive to inhibitors of actin filament formation, we propose that ADAM17 but not ADAM10 is prestored in a subcellular compartment that is transported to the cell surface in an activation- and actin-dependent manner.
    Full-text · Article · Oct 2013 · PLoS ONE
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    • "In addition to ADAM17, ADAM10 represents a candidate for EpCAM cleavage [14]. In fact, both EpCAM and ADAM10 have been found in TEMs (tetraspanin-enriched microdomains), membrane microdomains distinct from lipid rafts [43,44], which have been implicated in the regulation of ADAMs [45–48]. The localization of EpCAM and its interaction with certain binding partners in TEMs have been found to promote tumour progression in colon carcinoma cells [49]. "
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    ABSTRACT: The epithelial cell adhesion molecule (EpCAM; CD326) is highly expressed on epithelium-derived tumors and can play a role in cell proliferation. Recently, regulated intramembrane proteolysis (RIP) has been implicated as the trigger for EpCAM-mediated proliferative signaling. However, RIP does not explain all EpCAM-derived protein fragments. To shed light on how proteolytic cleavage is involved in EpCAM signaling, we characterized the protein biochemically using antibodies binding to three different EpCAM domains. Using a newly generated anti-EpCAM antibody, we find that EpCAM can be cleaved at multiple positions within its ectodomain in addition to described peptides, revealing that EpCAM is processed via distinct proteolytic pathways. Here, we report on four new peptides, but also discuss the previously described cleavage products to provide a comprehensive picture of EpCAM cleavage at multiple positions. The complex regulation of EpCAM might not only result in absence of full-length EpCAM, but the newly formed EpCAM-derived proteins may have their own signaling properties.
    Full-text · Article · Feb 2013 · Bioscience Reports
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