title: Expression of MAEG, a novel basement membrane protein, in mouse hair follicle morphogenesis.
abstract: We screened for genes specifically expressed in the mesenchymes of developing hair follicles using representational differential analysis; one gene identified was MAEG, which encodes a protein consisting of five EGF-like repeats, a linker segment containing a cell-adhesive Arg-Gly-Asp (RGD) motif, and a MAM domain. Immunohistochemistry showed that MAEG protein was localized at the basement membrane of embryonic skin and developing hair follicles, while MAEG expression diminished at the tip of the hair bud. A recombinant MAEG fragment containing the RGD motif was active in mediating adhesion of keratinocytes to the substratum in an RGD-dependent manner. One of the adhesion receptors recognizing the RGD motif was found to be the alpha8beta1 integrin, the expression of which was detected in the placode close to MAEG-positive mesenchymal cells, but later became restricted to the tip of the developing hair bud. Given its localized expression at the basement membrane in developing hair follicles and the RGD-dependent cell-adhesive activity, MAEG may play a role as a mediator regulating epithelial-mesenchymal interaction through binding to RGD-binding integrins including alpha8beta1 during hair follicle development.
authors.affiliation: Sekiguchi Biomatrix Signaling Project, ERATO, Japan Science and Technology Agency (JST), Aichi Medical University, Aichi 480-1195, Japan.
authors.forename: Aki
authors.initials: A
authors.lastname: Osada
authors.forename: Daiji
authors.initials: D
authors.lastname: Kiyozumi
authors.forename: Ko
authors.initials: K
authors.lastname: Tsutsui
authors.forename: Yuichi
authors.initials: Y
authors.lastname: Ono
authors.forename: Charles N
authors.initials: CN
authors.lastname: Weber
authors.forename: Nagisa
authors.initials: N
authors.lastname: Sugimoto
authors.forename: Toshio
authors.initials: T
authors.lastname: Imai
authors.forename: Akiko
authors.initials: A
authors.lastname: Okada
authors.forename: Kiyotoshi
authors.initials: K
authors.lastname: Sekiguchi
mesh_terms: D000818:Animals; D001485:Basement Membrane / Q000378:metabolism*; D002135:Calcium-Binding Proteins; D002448:Cell Adhesion / Q000502:physiology; D015815:Cell Adhesion Molecules; D002478:Cells, Cultured; D006023:Glycoproteins / Q000378:metabolism*; D018859:Hair Follicle / Q000378:metabolism*; D051379:Mice; D009024:Morphogenesis / Q000502:physiology*; D009363:Neoplasm Proteins / Q000378:metabolism*; D009842:Oligopeptides / Q000378:metabolism*; D010455:Peptides / Q000378:metabolism*; D011946:Receptors, Antigen / Q000378:metabolism
chemical_list: D002135:Calcium-Binding Proteins; D015815:Cell Adhesion Molecules; C485745:Egfl6 protein, mouse; D006023:Glycoproteins; D009363:Neoplasm Proteins; D009842:Oligopeptides; D010455:Peptides; D011946:Receptors, Antigen; C028641:Tn receptor; C047981:arginyl-glycyl-aspartic acid