Clostridium perfringens enterotoxin fragment removes specific claudins from tight junction strands: Evidence for direct involvement of claudins in tight junction barrier.
Claudins, comprising a multigene family, constitute tight junction (TJ) strands. Clostridium perfringens enterotoxin (CPE), a single approximately 35-kD polypeptide, was reported to specifically bind to claudin-3/RVP1 and claudin-4/CPE-R at its COOH-terminal half. We examined the effects of the COOH-terminal half fragment of CPE (C-CPE) on TJs in L transfectants expressing claudin-1 to -4 (C1L to C4L, respectively), and in MDCK I cells expressing claudin-1 and -4. C-CPE bound to claudin-3 and -4 with high affinity, but not to claudin-1 or -2. In the presence of C-CPE, reconstituted TJ strands in C3L cells gradually disintegrated and disappeared from their cell surface. In MDCK I cells incubated with C-CPE, claudin-4 was selectively removed from TJs with its concomitant degradation. At 4 h after incubation with C-CPE, TJ strands were disintegrated, and the number of TJ strands and the complexity of their network were markedly decreased. In good agreement with the time course of these morphological changes, the TJ barrier (TER and paracellular flux) of MDCK I cells was downregulated by C-CPE in a dose-dependent manner. These findings provided evidence for the direct involvement of claudins in the barrier functions of TJs.
Sonoda
N
N
Department of Cell Biology, Faculty of Medicine, Kyoto University, Sakyo-ku, Kyoto 606-8501, Japan.
Furuse
M
M
Sasaki
H
H
Yonemura
S
S
Katahira
J
J
Horiguchi
Y
Y
Tsukita
S
S
D000818:Animals; D016923:Cell Death / Q000187:drug effects; D002460:Cell Line; D002462:Cell Membrane / Q000187:drug effects / Q000378:metabolism / Q000648:ultrastructure; D048429:Cell Size / Q000187:drug effects; D062445:Claudin-1; D062465:Claudin-3; D062506:Claudin-4; D057167:Claudins; D003593:Cytoplasm / Q000187:drug effects / Q000378:metabolism / Q000648:ultrastructure; D004285:Dogs; D004305:Dose-Response Relationship, Drug; D015536:Down-Regulation / Q000187:drug effects; D017097:Electric Impedance; D004768:Enterotoxins / Q000494:pharmacology*; D005455:Fluorescent Antibody Technique; D007739:L Cells; D008565:Membrane Proteins / Q000235:genetics / Q000378:metabolism*; D051379:Mice; D010446:Peptide Fragments / Q000494:pharmacology*; D011485:Protein Binding; D019108:Tight Junctions / Q000187:drug effects / Q000378:metabolism* / Q000502:physiology / Q000648:ultrastructure; D013997:Time Factors; D014162:Transfection
D062445:Claudin-1; D062465:Claudin-3; D062506:Claudin-4; D057167:Claudins; C568113:Cldn1 protein, mouse; C113371:Cldn2 protein, mouse; C568123:Cldn3 protein, mouse; C568158:Cldn4 protein, mouse; D004768:Enterotoxins; D008565:Membrane Proteins; D010446:Peptide Fragments; C035598:enterotoxin, Clostridium