ADAMTS-1 Protein Anchors at the Extracellular Matrix through the Thrombospondin Type I Motifs and Its Spacing Region

Abstract

Cellular disintegrin and metalloproteinases (ADAMs) are a family of genes with a sequence similar to those of snake venom metalloproteinases and disintegrins. The ADAMTS-1 gene encodes a new type of ADAM protein with respect to possessing the thrombospondin (TSP) type I motifs. Expression of the gene is induced in kidney and heart by in vivo administration of lipopolysaccharide, suggesting a possible role in the inflammatory reaction. In this study, we characterized the ADAMTS-1 gene product by using a transient expression system in COS-7 cells. We found that the precursor and processed forms of ADAMTS-1 were secreted from cells. Under normal growth conditions, little or none of both forms was detected in the cell culture medium, and instead the majority was found associated with the extracellular matrix (ECM). In addition, when cells were cultured in the presence of heparin, the mature form of ADAMTS-1 protein was detected in the cell culture medium, suggesting that binding of ADAMTS-1 to the ECM is mediated through sulfated glycosaminoglycans such as heparan sulfate. Analyses of deletion mutants of the ADAMTS-1 protein revealed that the spacer region as well as three TSP type I motifs in the carboxyl-terminal region of the ADAMTS-1 protein are important for a tight interaction with the ECM. These results suggest that the ADAMTS-1 is a unique ADAM family protein that anchors at the ECM. Disintegrin and metalloproteinases (ADAMs)1 represent a new family of gene products that show significant sequence similarity to snake venom metalloproteinase and disintegrin (1, 2). So far, 18 -20 ADAM genes, including fertilin, epididymal apical protein I, cyritestin, meltrin, metalloproteinase-like/ disintegrin-like/cysteine-rich (MDC) protein, macrophage cellsurface antigen MS2, and metargidin, have been identified (3-8). Typical ADAMs are cell surface proteins that consist of a pro-, a metalloprotease-like, a disintegrin-like, a cysteine-rich, an epidermal growth factor-like, a transmembrane, and a cytoplasmic domain. Fertilin, the first ADAM described, has been implicated in integrin-mediated sperm-egg binding (3, 9); meltrin has been shown to be required for myotube formation (6). They are thought to function in cell-cell interaction. However, a recently cloned gene encoding tumor necrosis factor ␣ (TNF-␣)-converting enzyme (TACE) has been shown to be a membrane type metalloproteinase that also belongs to the ADAM family (10, 11). In Drosophila, an ADAM family gene, Kuzbanian has been demonstrated to play a role in the lateral inhibition during neurogenesis by cleavage of the extracellular domain of the transmembrane receptor Notch (12, 13). These observations indicate that some ADAMs, possessing a zinc binding motif, function by processing cell surface proteins. Interestingly, it has been found that mammalian disintegrinmetalloprotease (MADM or ADAM10) is also able to process pro-TNF-␣ (14, 15), whereas other ADAM members, MS2 and decysin, were identified as monocytic and dendritic cell-specific genes, respectively (7, 1...

Full-length ADAMTS-1 and the ADAMTS-1 fragments display pro- and antimetastatic activity, respectively

“…Like HB-EGF and AR, ADAMTS-1 binds to HS through its spacer region and the TSP-1 motifs (Kuno and Matsushima, 1998). HS/HSPG likely brings the metalloproteinase domain of ADAMTS-1 close to the HSPG-bound factors, making ADAMTS-1 an ideal sheddase for these HSPG-bound factors.…”

Characterization of ADAMTS-9 and ADAMTS-20 as a Distinct ADAMTS Subfamily Related to Caenorhabditis elegans GON-1

“…RNA in situ hybridization was performed essentially as previously described (19), using 35 S-labeled antisense and sense cRNA probes transcribed from a 600-nt cDNA template encoding the unique domain of ADAMTS-20. Normal human breast and lung samples as well as samples of squamous cell carcinoma of breast and adenocarcinoma of lung were obtained under a Cleveland Clinic Foundation Institutional Review Board-approved protocol and fixed in formalin (tissue samples were provided by the Cooperative Human Tissue Network).…”

“…Therefore, these are not predicted to be membrane-anchored enzymes. Accordingly, studies with various ADAMTS proteases have shown that they are soluble or associated with the ECM (3,4,35). ADAMTS-9 and ADAMTS-4 are therefore the first ADAMTS proteases shown to localize near the cell surface, as demonstrated by immunofluorescence microscopy, although their precise location relative to the cell membrane or the binding mechanism is presently unknown.…”

ADAMTS-1 and -4 are up-regulated following transient middle cerebral artery occlusion in the rat and their expression is modulated by TNF in cultured astrocytes

“…ADAMTS-1, -4, -5 and -9 have aggrecanase activity and are implicated in cartilage degradation [8], [40], [43]. The ADAMTS proteoglycanases are inhibited by tissue inhibitor of metalloproteinases (TIMP)-3 which, like the ADAMTSs, is sequestered in the ECM via interactions with sulphated glycosaminoglycans [11], [18], [47]. ADAMTS expression has been detected in the CNS [1], [17], [37] and is known to be altered in disease states [10], [22], [23].…”