Identification of a novel cell-adhesive protein spatiotemporally expressed in the basement membrane of mouse developing hair follicle

• Published in: Experimental cell research 2005-05, Vol.306 (1), p.9-23
• Main Authors: Kiyozumi, Daiji, Osada, Aki, Sugimoto, Nagisa, Weber, Charles N., Ono, Yuichi, Imai, Toshio, Okada, Akiko, Sekiguchi, Kiyotoshi
• Format: Article
• Language: English
• Subjects: Amino Acid Motifs - genetics; Amino Acid Sequence; Animal Structures - embryology; Animal Structures - metabolism; Animals; Basement membrane; Basement Membrane - embryology; Basement Membrane - metabolism; Binding Sites - genetics; Cell Adhesion - physiology; Chondroitin Sulfate Proteoglycans - genetics; Cloning, Molecular; DNA, Complementary - chemistry; DNA, Complementary - genetics; Extracellular matrix; Extracellular Matrix Proteins - genetics; Extracellular Matrix Proteins - metabolism; Female; Gene Expression Regulation, Developmental; Hair follicle; Hair Follicle - embryology; Hair Follicle - metabolism; HeLa Cells; Humans; In Situ Hybridization; Integrins - genetics; Integrins - metabolism; K562 Cells; Mice; Mice, Inbred ICR; Molecular Sequence Data; Recombinant Proteins - metabolism; RGD; Sequence Alignment; Sequence Analysis, DNA; Sequence Homology, Amino Acid; Tandem Repeat Sequences - genetics; Vibrissae - embryology; Vibrissae - metabolism
• ISSN: 0014-4827; 1090-2422
• DOI: 10.1016/j.yexcr.2005.01.020

We used PCR-based cDNA subtraction to screen for genes up-regulated during mouse hair morphogenesis. One gene selected was predominantly expressed at the tip of developing hair follicles and encoded a protein characterized by the presence of twelve tandem repeats of ∼120 amino acids and a novel N-terminal domain containing an Arg–Gly–Asp cell-adhesive motif. Immunohistochemistry demonstrated that the protein encoded by this gene, named QBRICK, was localized at the basement membrane zone of embryonic epidermis and hair follicles, in which it was more enriched at the tip rather than the stalk region. Cell adhesion assays showed that QBRICK was active in mediating cell-substratum adhesion through integrins containing αv or α8 chain, but not integrin α5β1. Immunohistochemistry showed that QBRICK colocalized with αv-containing integrins in the interfollicular region, but with the α8-containing integrin at the tip region of developing hair follicles. These results, together, indicate that QBRICK is an adhesive ligand of basement membrane distinctively recognized by cells in the embryonic skin and hair follicles through different types of integrins directed to the Arg–Gly–Asp motif.