TY - JOUR
T1 - The keratin-binding protein Albatross regulates polarization of epithelial cells
AU - Sugimoto, Masahiko
AU - Inoko, Akihito
AU - Shiromizu, Takashi
AU - Nakayama, Masanori
AU - Zou, Peng
AU - Yonemura, Shigenobu
AU - Hayashi, Yuko
AU - Izawa, Ichiro
AU - Sasoh, Mikio
AU - Uji, Yukitaka
AU - Kaibuchi, Kozo
AU - Kiyono, Tohru
AU - Inagaki, Masaki
PY - 2008/10/6
Y1 - 2008/10/6
N2 - The keratin intermediate filament network is abundant in epithelial cells, but its function in the establishment and maintenance of cell polarity is unclear. Here, we show that Albatross complexes with Par3 to regulate formation of the apical junctional complex (AJC) and maintain lateral membrane identity. In nonpolarized epithelial cells, Albatross localizes with keratin filaments, whereas in polarized epithelial cells, Albatross is primarily localized in the vicinity of the AJC. Knockdown of Albatross in polarized cells causes a disappearance of key components of the AJC at cell-cell borders and keratin filament reorganization. Lateral proteins E-cadherin and desmoglein 2 were mislocalized even on the apical side. Although Albatross promotes localization of Par3 to the AJC, Par3 and ezrin are still retained at the apical surface in Albatross knockdown cells, which retain intact microvilli. Analysis of keratin-deficient epithelial cells revealed that keratins are required to stabilize the Albatross protein, thus promoting the formation of AJC. We propose that keratins and the keratin-binding protein Albatross are important for epithelial cell polarization.
AB - The keratin intermediate filament network is abundant in epithelial cells, but its function in the establishment and maintenance of cell polarity is unclear. Here, we show that Albatross complexes with Par3 to regulate formation of the apical junctional complex (AJC) and maintain lateral membrane identity. In nonpolarized epithelial cells, Albatross localizes with keratin filaments, whereas in polarized epithelial cells, Albatross is primarily localized in the vicinity of the AJC. Knockdown of Albatross in polarized cells causes a disappearance of key components of the AJC at cell-cell borders and keratin filament reorganization. Lateral proteins E-cadherin and desmoglein 2 were mislocalized even on the apical side. Although Albatross promotes localization of Par3 to the AJC, Par3 and ezrin are still retained at the apical surface in Albatross knockdown cells, which retain intact microvilli. Analysis of keratin-deficient epithelial cells revealed that keratins are required to stabilize the Albatross protein, thus promoting the formation of AJC. We propose that keratins and the keratin-binding protein Albatross are important for epithelial cell polarization.
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U2 - 10.1083/jcb.200803133
DO - 10.1083/jcb.200803133
M3 - Article
C2 - 18838552
AN - SCOPUS:53749083534
SN - 0021-9525
VL - 183
SP - 19
EP - 28
JO - Journal of Cell Biology
JF - Journal of Cell Biology
IS - 1
ER -