title: Modulation of collagen fibrillogenesis by tenascin-X and type VI collagen.
abstract: Tenascin-X (TNX) is an extracellular matrix glycoprotein. We previously demonstrated that TNX regulates the expression of type VI collagen. In this study, we investigated the binding of TNX to type I collagen as well as to type VI collagen and the effects of these proteins on fibrillogenesis of type I collagen. Full-length recombinant TNX, which is expressed in and purified from mammalian cell cultures, and type VI collagen purified from bovine placenta were used. Solid-phase assays revealed that TNX or type VI collagen bound to type I collagen, although TNX did not bind to type VI collagen, fibronectin, or laminin. The rate of collagen fibril formation and its quantity, measured as increased turbidity, was markedly increased by the presence of TNX, whereas type VI collagen did not increase the quantity but accelerated the rate of collagen fibril formation. Combined treatment of both had an additive effect on the rate of collagen fibril formation. Furthermore, deletion of the epidermal growth factor-like (EGF) domain or fibrinogen-like domain of TNX attenuated the initial rate of collagen fibril formation. Finally, we observed abnormally large collagen fibrils by electron microscopy in the skin from TNX-deficient (TNX-/-) mice during development. These findings demonstrate a fundamental role for TNX and type VI collagen in regulation of collagen fibrillogenesis in vivo and in vitro.
authors.affiliation: Department of Molecular Biology, Graduate School of Pharmaceutical Sciences, Hokkaido University, Kita, Sapporo 060-0812, Japan.
authors.forename: Takeharu
authors.initials: T
authors.lastname: Minamitani
authors.forename: Tomoki
authors.initials: T
authors.lastname: Ikuta
authors.forename: Yoshinari
authors.initials: Y
authors.lastname: Saito
authors.forename: Gen
authors.initials: G
authors.lastname: Takebe
authors.forename: Mami
authors.initials: M
authors.lastname: Sato
authors.forename: Hirofumi
authors.initials: H
authors.lastname: Sawa
authors.forename: Takanori
authors.initials: T
authors.lastname: Nishimura
authors.forename: Fumio
authors.initials: F
authors.lastname: Nakamura
authors.forename: Kazuhiko
authors.initials: K
authors.lastname: Takahashi
authors.forename: Hiroyoshi
authors.initials: H
authors.lastname: Ariga
authors.forename: Ken-ichi
authors.initials: K
authors.lastname: Matsumoto
mesh_terms: D000818:Animals; D002460:Cell Line; D024042:Collagen Type I / Q000096:biosynthesis* / Q000648:ultrastructure; D024142:Collagen Type VI / Q000378:metabolism*; D005109:Extracellular Matrix / Q000235:genetics* / Q000378:metabolism / Q000648:ultrastructure; D006801:Humans; D051379:Mice; D018345:Mice, Knockout; D008854:Microscopy, Electron; D016297:Mutagenesis, Site-Directed; D011485:Protein Binding / Q000235:genetics; D017434:Protein Structure, Tertiary / Q000235:genetics; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000378:metabolism; D012868:Skin Abnormalities / Q000235:genetics / Q000378:metabolism; D019063:Tenascin / Q000235:genetics* / Q000302:isolation & purification / Q000378:metabolism*
chemical_list: D024042:Collagen Type I; D024142:Collagen Type VI; D011993:Recombinant Fusion Proteins; D019063:Tenascin; C081865:tenascin X