CDB15:0000024 ADAM9 — ITGB1
Experimentally validated in Human, Mixed species; Orthology-inferred in Human, Mouse, Rat, Frog, Zebrafish, Chicken, Macaque, Pig, Dog, Cow, Chimp, Horse, Marmoset, Sheep
Title
Journal:; Year Published:
Abstract
Meltrin gamma(ADAM-9) mediates cellular adhesion through alpha(6)beta(1 )integrin, leading to a marked induction of fibroblast cell motility.
Journal of cell science, 2000; PubMed, Mus Musculus Adam9 — Homo sapiens ITGB1
ABSTRACT: The ADAMs (A Disintegrin and Metalloprotease Domains) are a family of membrane-anchored proteins that play a role in fertilisation, myoblast fusion and ectodomain shedding of cell surface proteins. Meltrin gamma (ADAM-9) is a widely expressed member of this family and is involved in the shedding of heparin binding epidermal growth factor. Here we report that meltrin gamma can function as a cell adhesion molecule via its disintegrin domain. Using solid-phase binding assays and antibody inhibition experiments, we demonstrate that a murine meltrin gamma-Fc (Mel gamma -Fc) fusion protein binds to the integrin alpha(6)beta(1) on the surface of fibroblast cell lines, HT1080 and Wehi 164 in a specific manner. Since alpha(6)beta(1) is important for the motility of several cell types on laminin, cell migration studies using time-lapse video microscopy were performed. Cells adhering to Mel gamma-Fc displayed a rounded morphology and a marked increase (eight- to tenfold) in their motility compared to that on laminin. Furthermore, the p160 ROCK kinase inhibitor Y-27632 specifically reduced the migration of cells on meltrin gamma but had no effect on migration of cells on laminin, whilst the general tyrosine phoshorylation inhibitor, genistein, inhibited cell migration on both substrates. These results together suggest that meltrin gamma may play a role in regulating the motility of cells by binding to alpha(6)beta(1) integrin and this may be important during a variety of biological and pathological processes.
The disintegrin domain of ADAM9: a ligand for multiple beta1 renal integrins.
The Biochemical journal, 2005; PubMed, Homo sapiens ADAM9 — Homo sapiens ITGB1
ABSTRACT: Renal tubular epithelial cells in all nephron segments express a distinct member of the metalloprotease-disintegrin family, ADAM9 (a disintegrin and metalloprotease 9), in a punctate basolateral distribution co-localized to the beta1 integrin chain [Mahimkar, Baricos, Visaya, Pollock and Lovett (2000) J. Am. Soc. Nephrol. 11, 595-603]. Discrete segments of the nephron express several defined beta1 integrins, suggesting that ADAM9 interacts with multiple renal integrins and thereby regulates epithelial cell-matrix interactions. Intact ADAM9 and a series of deletion constructs sequentially lacking the metalloprotease domain and the disintegrin domain were assembled as chimaeras with a C-terminal GFP (green fluorescent protein) tag. Stable expression of the ADAM9/GFP protein on the surface of HEK-293 cells (human embryonic kidney 293 cells) significantly decreased adhesion to types I and IV collagen, vitronectin and laminin, but had little effect on adhesion to fibronectin. Expression of the disintegrin/cysteine-rich/GFP construct yielded a similar, but more marked pattern of decreased adhesion. Expression of the cysteine-rich/GFP construct had no effect on adhesion, indicating that the disintegrin domain was responsible for the competitive inhibition of cell-matrix binding. To define the specific renal tubular beta1 integrins interacting with the ADAM9 disintegrin domain, a recombinant GST (glutathione S-transferase)-disintegrin protein was used as a substrate in adhesion assays in the presence or absence of specific integrin-blocking antibodies. Inclusion of antibodies to alpha1, alpha3, alpha6, alphav and beta1 blocked adhesion of HEK-293 cells to GST-disintegrin protein. Immobilized GST-disintegrin domain perfused with renal cortical lysates specifically recovered the alpha3, alpha6, alphav and beta1 integrin chains by Western analysis. It is concluded that ADAM9 is a polyvalent ligand, through its disintegrin domain, for multiple renal integrins of the beta1 class.