Letter | Published:

Yurt, Coracle, Neurexin IV and the Na+,K+-ATPase form a novel group of epithelial polarity proteins

Nature volume 459, pages 11411145 (25 June 2009) | Download Citation



The integrity of polarized epithelia is critical for development and human health. Many questions remain concerning the full complement and the function of the proteins that regulate cell polarity1. Here we report that the Drosophila FERM proteins Yurt (Yrt)2 and Coracle (Cora)3 and the membrane proteins Neurexin IV (Nrx-IV)4 and Na+,K+-ATPase5 are a new group of functionally cooperating epithelial polarity proteins. This ‘Yrt/Cora group’ promotes basolateral membrane stability and shows negative regulatory interactions with the apical determinant Crumbs (Crb). Genetic analyses indicate that Nrx-IV and Na+,K+-ATPase act together with Cora in one pathway, whereas Yrt acts in a second redundant pathway. Moreover, we show that the Yrt/Cora group is essential for epithelial polarity during organogenesis but not when epithelial polarity is first established or during terminal differentiation. This property of Yrt/Cora group proteins explains the recovery of polarity in embryos lacking the function of the Lethal giant larvae (Lgl) group of basolateral polarity proteins6,7. We also find that the mammalian Yrt orthologue EPB41L5 (also known as YMO1 and Limulus)8,9,10 is required for lateral membrane formation, indicating a conserved function of Yrt proteins in epithelial polarity.

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We would like to thank V. Auld, J. Casanova, H. Bellen, M. Hortsch, R. Fehon, M. Bhat, R. Schuh, the Developmental Studies Hybridoma Bank and the Bloomington Drosophila Stock Center for reagents. We thank D. Godt, R. Winklbauer and T. Harris for critical comments on the manuscript, and H. Hong, M. Pellikka and W. Russin for technical assistance. This work was supported by postdoctoral fellowships from the CIHR (to P.L.), a predoctoral fellowship from the Vision Science Research Program, University of Toronto (to S.B.) and by NIH Lung Biology Training Grant 5 (to S.M.P.). Operating support was provided by the CIHR (to U.T. and P.L.), the Foundation Fighting Blindness Canada (to C.J.M.) and the NIH (to G.J.B.).

Author information

Author notes

    • Patrick Laprise
    •  & Slobodan Beronja

    Present addresses: Laval University Cancer Research Center, CRCHUQ-Hôtel-Dieu de Québec, Québec City, Québec G1R 2J6,Canada (P.L.); Howard Hughes Medical Institute, Laboratory of Mammalian Cell Biology and Development, The Rockefeller University, New York, New York 10021, USA (S.B.).


  1. Department of Cell and Systems Biology, University of Toronto, Toronto, Ontario M5S 3G5, Canada

    • Patrick Laprise
    • , Kathryn P. Harris
    • , Slobodan Beronja
    •  & Ulrich Tepass
  2. Department of Medical Biophysics, University of Toronto and The Arthur and Sonia Labatt Brain Tumour Research Centre, Hospital for Sick Children, Toronto, Ontario M5G 1X8, Canada

    • Kimberly M. Lau
    • , Nancy F. Silva-Gagliardi
    •  & C. Jane McGlade
  3. Department of Biochemistry, Molecular Biology and Cell Biology, Northwestern University, Evanston, Illinois 60208, USA

    • Sarah M. Paul
    •  & Greg J. Beitel


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Corresponding author

Correspondence to Ulrich Tepass.

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