Post-translational regulation and proteolytic activity of human adamts-8: a comparison with adamts-1, -4, and -5

ABSTRACT: A Disintegrin-like And Metalloprotease with Thrombospondin type 1 motifs (ADAMTS)-8 is a secreted protease which has been recently implicated in the pathogenesis of pulmonary arterial hypertension (PAH). However, the substrate repertoire of ADAMTS-8 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 ADAMTS-1, -4, -5 and -15, as well as tight genetic linkage with ADAMTS-15 on human chromosome 11, its aggrecanase activity was reported to be weak. A number of post-translational modifications regulate ADAMTS proteases such as autolysis, inhibition by endogenous inhibitors and receptor-mediated endocytosis, but their impact on ADAMTS-8 is unknown. Here, we show that ADAMTS-8 undergoes autolysis at six different sites within its spacer domain. We also found that ADAMTS-8 cleaves osteopontin, a phosphoprotein whose expression is upregulated in PAH. Multiple ADAMTS-8 cleavage sites were identified using liquid chromatography- tandem mass spectrometry. Osteopontin cleavage by ADAMTS-8 is efficiently inhibited by TIMP-3, an endogenous inhibitor of ADAMTS-1, -4 and -5, as well as TIMP-2, which has no reported inhibitory activity against other ADAMTS family members. These differences in post-translational regulation and substrate repertoire differentiate ADAMTS-8 from other family members and may help to elucidate its role in PAH.

INSTRUMENT(S): Orbitrap Fusion Lumos

ORGANISM(S): Homo Sapiens (human)

DISEASE(S): Pulmonary Hypertension

SUBMITTER: Daniel Martin  

LAB HEAD: Suneel Apte

PROVIDER: PXD027724 | Pride | 2022-02-17

REPOSITORIES: Pride