TY - JOUR
T1 - Cholesterol-rich domain formation mediated by ZO proteins is essential for tight junction formation
AU - Shigetomi, Kenta
AU - Ono, Yumiko
AU - Matsuzawa, Kenji
AU - Ikenouchi, Junichi
N1 - Funding Information:
ACKNOWLEDGMENTS. We thank all members of the Ikenouchi laboratory (Department of Biology, Faculty of Sciences, Kyushu University) for helpful discussions. We also thank the Ultramicroscopy Research Center of Kyushu University, Dr. T. Inai (Fukuoka Dental College), and Dr. Y. Fukazawa (Fukui university) for their invaluable guidance and assistance of EM studies.This work was supported by JSPS KAKENHI [JP22H02618 (J.I.), JP21K19231 (J.I.), JP21K15089 (K.S.), JP20K22632 (K.S.), and JP16H06280 (Grant-in-Aid for Scientific Research on Innovative Areas, Platforms for Advanced Technologies and Research Resources “Advanced Bioimaging Support”)], AMED-FORCE (21444781) (J.I.), JST-FOREST (JPMJFR204L) (J.I.), and grants from the Mitsubishi Foundation (J.I.) and the Cell Science Research Foundation (J.I.).
Publisher Copyright:
Copyright © 2023 the Author(s).
PY - 2023/2/21
Y1 - 2023/2/21
N2 - Tight junctions (TJs) are cell-adhesion structures responsible for the epithelial barrier. We reported that accumulation of cholesterol at the apical junctions is required for TJ formation [K. Shigetomi, Y. Ono, T. Inai, J. Ikenouchi, J. Cell Biol. 217, 2373–2381 (2018)]. However, it is unclear how cholesterol accumulates and informs TJ formation—and whether cholesterol enrichment precedes or follows the assembly of claudins in the first place. Here, we established an epithelial cell line (claudin-null cells) that lacks TJs by knocking out claudins. Despite the lack of TJs, cholesterol normally accumulated in the vicinity of the apical junctions. Assembly of claudins at TJs is thought to require binding to zonula occludens (ZO) proteins; however, a claudin mutant that cannot bind to ZO proteins still formed TJ strands. ZO proteins were however necessary for cholesterol accumulation at the apical junctions through their effect on the junctional actomyosin cytoskeleton. We propose that ZO proteins not only function as scaffolds for claudins but also promote TJ formation of cholesterol-rich membrane domains at apical junctions.
AB - Tight junctions (TJs) are cell-adhesion structures responsible for the epithelial barrier. We reported that accumulation of cholesterol at the apical junctions is required for TJ formation [K. Shigetomi, Y. Ono, T. Inai, J. Ikenouchi, J. Cell Biol. 217, 2373–2381 (2018)]. However, it is unclear how cholesterol accumulates and informs TJ formation—and whether cholesterol enrichment precedes or follows the assembly of claudins in the first place. Here, we established an epithelial cell line (claudin-null cells) that lacks TJs by knocking out claudins. Despite the lack of TJs, cholesterol normally accumulated in the vicinity of the apical junctions. Assembly of claudins at TJs is thought to require binding to zonula occludens (ZO) proteins; however, a claudin mutant that cannot bind to ZO proteins still formed TJ strands. ZO proteins were however necessary for cholesterol accumulation at the apical junctions through their effect on the junctional actomyosin cytoskeleton. We propose that ZO proteins not only function as scaffolds for claudins but also promote TJ formation of cholesterol-rich membrane domains at apical junctions.
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U2 - 10.1073/pnas.2217561120
DO - 10.1073/pnas.2217561120
M3 - Article
C2 - 36791108
AN - SCOPUS:85148250611
SN - 0027-8424
VL - 120
JO - Proceedings of the National Academy of Sciences of the United States of America
JF - Proceedings of the National Academy of Sciences of the United States of America
IS - 8
M1 - e2217561120
ER -