An in vitro cleavage assay shows TSP1 is a direct substrate of HtrA1. TSP1 (500 ng) were incubated with the indicated amount of active HtrA1WT (WT) (OriGene TP322362) or inactive HtrA1S328A (S328A) (OriGene TP700208). The cleavage events were analyzed by immunoblotting. Filled triangle is the full-length form of TSP1 and HtrA1. Empty triangle is proteolysis products. TSP1 was probed using an antibody specific to the N-terminal domain. The molecular weight (kDa) reference is indicated in the left side of the image. Figure cited from Matrix Biol, PMID: 29572155

HtrA1 degrades preformed microtubules and avoids polymerization in vitro. Fluorescently labeled microtubules were polymerized in vitro and incubated with S328A HtrA1 (OriGene, TP700208) (center) and HtrA1 (OriGene, TP322362) (right). Images were acquired at 5 minutes, 6 hours, and 24 hours after adding HtrA1. Scale bar, 10 um. Figure cited from EBioMedicine, PMID: 29269042