title: Molecular architecture of tight junctions of periderm differs from that of the maculae occludentes of epidermis.
abstract: Occludin and claudins are tetraspan-transmembrane proteins in tight junctions. Maculae occludentes, which are less-developed tight junctions, occur in the granular cell layer of the epidermis. The periderm, which overlies the developing epidermis and functions as a protective layer for the embryo, carries developed tight junctions as observed in simple epithelia. In both periderm and epidermis, occludin is expressed at the cell-cell border. To determine the difference between tight junctions of periderm and epidermis, claudin-6 expression was examined in periderm and epidermis. Immunofluorescence staining showed claudin-6 expression at the cell-cell border of the periderm, but not in the epidermis. Reverse transcription-polymerase chain reaction confirmed that claudin-6 was not expressed in mouse adult skin, whereas immunoelectron microscopy revealed that claudin-6 was localized at tight junctions of the periderm. Furthermore, L fibroblasts with stable expression of exogenous claudin-6 formed developed tight junctions at cell-cell borders. These findings indicate that molecular architecture of tight junctions of the periderm is different from that of the maculae occludentes of the epidermis, and that claudin-6 is important in the formation of tight junctions of the periderm.
authors.affiliation: Department of Dermatology, Graduate School of Medicine, Kyoto University, Sakyo-ku, Kyoto, Japan. kamorita@kuhp.kyotou.ac.jp
authors.forename: Kazumasa
authors.initials: K
authors.lastname: Morita
authors.forename: Mikio
authors.initials: M
authors.lastname: Furuse
authors.forename: Yoko
authors.initials: Y
authors.lastname: Yoshida
authors.forename: Masahiko
authors.initials: M
authors.lastname: Itoh
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Sasaki
authors.forename: Shoichiro
authors.initials: S
authors.lastname: Tsukita
authors.forename: Yoshiki
authors.initials: Y
authors.lastname: Miyachi
mesh_terms: D000818:Animals; D057167:Claudins; D020405:Dermis / Q000737:chemistry / Q000166:cytology*; D000078404:Epidermal Cells; D004817:Epidermis / Q000737:chemistry; D005260:Female; D005347:Fibroblasts / Q000502:physiology; D005614:Freeze Fracturing; D008297:Male; D008565:Membrane Proteins / Q000032:analysis* / Q000235:genetics; D051379:Mice; D016253:Microscopy, Immunoelectron; D010750:Phosphoproteins / Q000032:analysis; D011247:Pregnancy; D019108:Tight Junctions / Q000737:chemistry* / Q000648:ultrastructure; D014162:Transfection; D062826:Zonula Occludens-1 Protein; D062827:Zonula Occludens-2 Protein
chemical_list: D057167:Claudins; D008565:Membrane Proteins; D010750:Phosphoproteins; C569043:Tjp1 protein, mouse; C569047:Tjp2 protein, mouse; D062826:Zonula Occludens-1 Protein; D062827:Zonula Occludens-2 Protein; C122101:claudin 6