Surface Proteomics of ADAM15 Knock-Down cells

ADAM15 is a member of the disintegrin-metalloproteinase family of sheddases, which plays a role in several biological processes including cartilage homeostasis. Contrary to well-characterized ADAMs, little is known about ADAM15 substrates or how the enzyme exerts its biological functions. Herein, we used “surface-spanning enrichment with click-sugars (SUSPECS)” proteomics to identify ADAM15 substrates and/or proteins regulated by the proteinase at the surface of chondrocyte-like cells. ADAM15-silencing significantly altered membrane levels of 13 proteins, but none of these was a canonical substrate. We used orthogonal techniques to validate ADAM15 effects on 3 of these proteins which have known roles in cartilage homeostasis. This confirmed that ADAM15-silencing increased levels of PDCD1LG2 and reduced levels of vasorin and SLC26A2 through an unknown post-translational mechanism.