Claudin-1 and -2: Novel Integral Membrane Proteins Localizing at Tight Junctions with No Sequence Similarity to Occludin
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- Mikio Furuse
- *Department of Cell Biology, ‡Department of Neurosurgery, and §Department of Anatomy, Faculty of Medicine, Kyoto University, Sakyo-ku, Kyoto 606, Japan
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- Kohji Fujita
- *Department of Cell Biology, ‡Department of Neurosurgery, and §Department of Anatomy, Faculty of Medicine, Kyoto University, Sakyo-ku, Kyoto 606, Japan
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- Takashi Hiiragi
- *Department of Cell Biology, ‡Department of Neurosurgery, and §Department of Anatomy, Faculty of Medicine, Kyoto University, Sakyo-ku, Kyoto 606, Japan
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- Kazushi Fujimoto
- *Department of Cell Biology, ‡Department of Neurosurgery, and §Department of Anatomy, Faculty of Medicine, Kyoto University, Sakyo-ku, Kyoto 606, Japan
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- Shoichiro Tsukita
- *Department of Cell Biology, ‡Department of Neurosurgery, and §Department of Anatomy, Faculty of Medicine, Kyoto University, Sakyo-ku, Kyoto 606, Japan
書誌事項
- 公開日
- 1998-06-29
- DOI
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- 10.1083/jcb.141.7.1539
- 公開者
- Rockefeller University Press
この論文をさがす
説明
<jats:p>Occludin is the only known integral membrane protein localizing at tight junctions (TJ), but recent targeted disruption analysis of the occludin gene indicated the existence of as yet unidentified integral membrane proteins in TJ. We therefore re-examined the isolated junction fraction from chicken liver, from which occludin was first identified. Among numerous components of this fraction, only a broad silver-stained band ∼22 kD was detected with the occludin band through 4 M guanidine-HCl extraction as well as sonication followed by stepwise sucrose density gradient centrifugation. Two distinct peptide sequences were obtained from the lower and upper halves of the broad band, and similarity searches of databases allowed us to isolate two full-length cDNAs encoding related mouse 22-kD proteins consisting of 211 and 230 amino acids, respectively. Hydrophilicity analysis suggested that both bore four transmembrane domains, although they did not show any sequence similarity to occludin. Immunofluorescence and immunoelectron microscopy revealed that both proteins tagged with FLAG or GFP were targeted to and incorporated into the TJ strand itself. We designated them as “claudin-1” and “claudin-2”, respectively. Although the precise structure/function relationship of the claudins to TJ still remains elusive, these findings indicated that multiple integral membrane proteins with four putative transmembrane domains, occludin and claudins, constitute TJ strands.</jats:p>
収録刊行物
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- The Journal of Cell Biology
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The Journal of Cell Biology 141 (7), 1539-1550, 1998-06-29
Rockefeller University Press
