title: Crystal structure of a claudin provides insight into the architecture of tight junctions.
abstract: Tight junctions are cell-cell adhesion structures in epithelial cell sheets that surround organ compartments in multicellular organisms and regulate the permeation of ions through the intercellular space. Claudins are the major constituents of tight junctions and form strands that mediate cell adhesion and function as paracellular barriers. We report the structure of mammalian claudin-15 at a resolution of 2.4 angstroms. The structure reveals a characteristic β-sheet fold comprising two extracellular segments, which is anchored to a transmembrane four-helix bundle by a consensus motif. Our analyses suggest potential paracellular pathways with distinctive charges on the extracellular surface, providing insight into the molecular basis of ion homeostasis across tight junctions.
authors.affiliation: Cellular and Structural Physiology Institute, Nagoya University, Chikusa, Nagoya 464-8601, Japan.
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Suzuki
authors.forename: Tomohiro
authors.initials: T
authors.lastname: Nishizawa
authors.forename: Kazutoshi
authors.initials: K
authors.lastname: Tani
authors.forename: Yuji
authors.initials: Y
authors.lastname: Yamazaki
authors.forename: Atsushi
authors.initials: A
authors.lastname: Tamura
authors.forename: Ryuichiro
authors.initials: R
authors.lastname: Ishitani
authors.forename: Naoshi
authors.initials: N
authors.lastname: Dohmae
authors.forename: Sachiko
authors.initials: S
authors.lastname: Tsukita
authors.forename: Osamu
authors.initials: O
authors.lastname: Nureki
authors.forename: Yoshinori
authors.initials: Y
authors.lastname: Fujiyoshi
mesh_terms: D020816:Amino Acid Motifs; D000595:Amino Acid Sequence; D000818:Animals; D057167:Claudins / Q000737:chemistry*; D018360:Crystallography, X-Ray; D051379:Mice; D008958:Models, Molecular; D008969:Molecular Sequence Data; D011487:Protein Conformation; D017510:Protein Folding; D017433:Protein Structure, Secondary; D017434:Protein Structure, Tertiary; D021122:Protein Subunits / Q000737:chemistry; D055672:Static Electricity; D019108:Tight Junctions / Q000737:chemistry* / Q000502:physiology
chemical_list: D057167:Claudins; D021122:Protein Subunits; C459596:claudin 15