Lipid polarity is maintained in absence of tight junctions

Junichi Ikenouchi, Mayu Suzuki, Kazuaki Umeda, Kazutaka Ikeda, Ryo Taguchi, Tetsuyuki Kobayashi, Satoshi B. Sato, Toshihide Kobayashi, Donna B. Stolz, Masato Umeda

Research output: Contribution to journalArticlepeer-review

38 Citations (Scopus)


The role of tight junctions (TJs) in the establishment and maintenance of lipid polarity in epithelial cells has long been a subject of controversy. We have addressed this issue using lysenin, a toxin derived from earthworms, and an influenza virus labeled with a fluorescent lipid, octadecylrhodamine B (R18). Whenepithelial cells are stained with lysenin, lysenin selectively binds to their apical membranes. Using an artificial liposome, we demonstrated that lysenin recognizes the membrane domains where sphingomyelins are clustered. Interestingly, lysenin selectively stained the apical membranes of epithelial cells depleted of zonula occludens proteins (ZO-deficient cells), which completely lack TJs. Furthermore, the fluorescent lipid inserted into the apical membrane by fusion with the influenza virus did not diffuse to the lateral membrane in ZO-deficient epithelial cells. This study revealed that sphingomyelin-cluster formation occurs only in the apical membrane and that lipid polarity is maintained even in the absence of TJs.

Original languageEnglish
Pages (from-to)9525-9533
Number of pages9
JournalJournal of Biological Chemistry
Issue number12
Publication statusPublished - Mar 16 2012
Externally publishedYes

All Science Journal Classification (ASJC) codes

  • Biochemistry
  • Molecular Biology
  • Cell Biology


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