CDB15:0001099 NID1 — ITGB3
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
Two distinct cell attachment sites in entactin are revealed by amino acid substitutions and deletion of the RGD sequence in the cysteine-rich epidermal growth factor repeat 2.
The Journal of biological chemistry, 1995; PubMed, Mus Musculus Nid1 — Homo sapiens ITGB3
ABSTRACT: The basement membrane glycoprotein, entactin, has previously been shown to promote cell attachment and chemotaxis. We have constructed a panel of glutathione S-transferase fusion proteins that encompasses the four major structural domains of entactin, G1, G2, E, and G3. These proteins have been synthesized in bacteria and purified by affinity chromatography. The connecting stalk of entactin, E, which contains four cysteine-rich EGF homology repeats and the integrin receptor RGD recognition sequence, has been modified by deletion of the RGD sequence and substituting glutamic acid for aspartic acid. Attachment assays reveal that the RGD sequence is one of the major cell attachment sites in entactin and that this sequence is recognized by the alpha v beta 3 integrin receptor. Analysis of cell attachment on mutant forms of full-length entactin expressed in the baculovirus expression system revealed a second attachment site that was independent of the RGD sequence. This second site was localized to a peptide of 39 amino acid residues in the second globular G2 domain of entactin. This peptide represents a cysteine-rich EGF repeat. Inhibition of cell attachment by anti-integrin receptor antibodies indicates that the second attachment site is recognized by a member of the beta 1 family of integrin receptors, possibly alpha 3 beta 1.
Human trophoblast cell adhesion to extracellular matrix protein, entactin.
American journal of reproductive immunology, 1996; PubMed, Homo sapiens NID1 — Homo sapiens ITGB3
ABSTRACT: Trophoblast interaction with endometrial extracellular matrix (ECM) is crucial during human embryo implantation and placentation. Entactin, a ubiquitous basement membrane glycoprotein, plays a central role in ECM assembly, cell attachment, and chemotaxis. The present study was conducted to examine the possible role of entactin in promoting human trophoblast adhesion.
Adhesion of cultured human kidney mesangial cells to native entactin: role of integrin receptors.
Cell adhesion and communication, 1998; PubMed, Homo sapiens NID1 — Homo sapiens ITGB3
ABSTRACT: Entactin is an extracellular matrix glycoprotein which binds to laminin and is found in most renal basement membranes and in the glomerular mesangial matrix. In the present study, we have characterized specific integrin receptors on cultured human mesangial cells (CHMC) responsible for adhesion to native entactin. The integrin receptors alpha 2 beta 1, alpha 3 beta 1, alpha 5 beta 1, alpha v beta 3, alpha v beta 5, and alpha 6 complexed with either beta 1 or beta 4 could be immune precipitated from detergent extracts of metabolically labeled CHMC. Adhesion assays with inhibitory anti integrin monoclonal antibodies (mab) demonstrated that CHMC use both alpha v beta 3 and a beta 1-containing integrin to bind surfaces coated with native entactin. Optimal binding of CHMC to native entactin required the participation of cations. Using wild type and mutant recombinant entactin fragments, the binding site for the alpha v beta 3 receptor was localized to the RGD sequence on the rod or E domain of entactin. CHMC adhesion to mutant full length recombinant entactin ligands lacking the E domain RGD sequence confirmed the presence of ligand binding site(s) for beta 1 integrin receptor(s). Differences in CHMC binding characteristics to recombinant and full length entactin compared to native bovine basement membrane entactin were observed. This suggests that tertiary molecular structure may contribute to entactin ligand binding properties. Primary amino acid residue sequences and tertiary structure of entactin may play roles in forming functional cell attachment sites in native basement membrane entactin.