Post-translational regulation and proteolytic activity of the metalloproteinase ADAMTS8



Santamaria, Salvatore, Martin, Daniel R, Dong, Xiangyi, Yamamoto, Kazuhiro ORCID: 0000-0002-8481-775X, Apte, Suneel S and Ahnstrom, Josefin
(2021) Post-translational regulation and proteolytic activity of the metalloproteinase ADAMTS8. JOURNAL OF BIOLOGICAL CHEMISTRY, 297 (5). 101323-.

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Abstract

A disintegrin-like and metalloprotease domain with thrombospondin type 1 motifs (ADAMTS)8 is a secreted protease, which was recently implicated in pathogenesis of pulmonary arterial hypertension (PAH). However, the substrate repertoire of ADAMTS8 and regulation of its activity are incompletely understood. Although considered a proteoglycanase because of high sequence similarity and close phylogenetic relationship to the proteoglycan-degrading proteases ADAMTS1, 4, 5, and 15, as well as tight genetic linkage with ADAMTS15 on human chromosome 11, its aggrecanase activity was reportedly weak. Several post-translational factors are known to regulate ADAMTS proteases such as autolysis, inhibition by endogenous inhibitors, and receptor-mediated endocytosis, but their impacts on ADAMTS8 are unknown. Here, we show that ADAMTS8 undergoes autolysis at six different sites within its spacer domain. We also found that in contrast to ADAMTS4 and 5, ADAMTS8 levels were not regulated through low-density lipoprotein receptor-related protein 1 (LRP1)-mediated endocytosis. Additionally, ADAMTS8 lacked significant activity against the proteoglycans aggrecan, versican, and biglycan. Instead, we found that ADAMTS8 cleaved osteopontin, a phosphoprotein whose expression is upregulated in PAH. Multiple ADAMTS8 cleavage sites were identified using liquid chromatography-tandem mass spectrometry. Osteopontin cleavage by ADAMTS8 was efficiently inhibited by TIMP-3, an endogenous inhibitor of ADAMTS1, 4, and 5, as well as by TIMP-2, which has no previously reported inhibitory activity against other ADAMTS proteases. These differences in post-translational regulation and substrate repertoire differentiate ADAMTS8 from other family members and may help to elucidate its role in PAH.

Item Type: Article
Uncontrolled Keywords: ADAMTS, TIMP, aggrecan, osteopontin, proteoglycan, versican, ADAMTS Proteins, HEK293 Cells, Humans, Osteopontin, Protein Processing, Post-Translational, Proteoglycans, Proteolysis, Pulmonary Arterial Hypertension, Tissue Inhibitor of Metalloproteinase-3
Divisions: Faculty of Health and Life Sciences
Faculty of Health and Life Sciences > Institute of Life Courses and Medical Sciences
Depositing User: Symplectic Admin
Date Deposited: 17 Jan 2022 11:39
Last Modified: 26 Jan 2023 01:56
DOI: 10.1016/j.jbc.2021.101323
Related URLs:
URI: https://livrepository.liverpool.ac.uk/id/eprint/3147017