TY - JOUR
T1 - Crumbs 3b promotes tight junctions in an ezrin-dependent manner in mammalian cells
AU - Tilston-Lünel, Andrew M.
AU - Haley, Kathryn E.
AU - Schlecht, Nicolas F.
AU - Wang, Yanhua
AU - Chatterton, Abigail L. D.
AU - Moleirinho, Susana
AU - Watson, Ailsa
AU - Hundal, Harinder S.
AU - Prystowsky, Michael B.
AU - Gunn-Moore, Frank J.
AU - Reynolds, Paul A.
N1 - A.M.T.-L. is supported by the School of Biology, University of St Andrews. A.M.T.-L., P.A.R., and F.J.G.-M. were funded by the Anonymous Trust, University of St Andrews. P.A.R. is supported
by the Melville Trust for the Care and Cure of Cancer. The mass spectrometry work was supported by the Wellcome Trust (grant
number 094476/Z/10/Z), which funded the purchase of the TripleTOF 5600 mass spectrometer at the BSRC Mass Spectrometry and Proteomics Facility, University of St Andrews. The clinical study was supported by the Department of Pathology, Albert Einstein College of Medicine/Montefiore Medical Center.
PY - 2016/10
Y1 - 2016/10
N2 - Crumbs 3 (CRB3) is a component of epithelial junctions, which has been implicated in apical-basal polarity, apical identity, apical stability, cell adhesion, and cell growth. CRB3 undergoes alternative splicing to yield two variants: CRB3a and CRB3b. Here, we describe novel data demonstrating that, as with previous studies on CRB3a, CRB3b also promotes the formation of tight junctions (TJs). However, significantly we demonstrate that the 4.1-ezrin-radixin-moesin-binding motif of CRB3b is required for CRB3b functionality and that ezrin binds to the FBM of CRB3b. Furthermore, we show that ezrin contributes to CRB3b functionality and the correct distribution of TJ proteins. We demonstrate that both CRB3 isoforms are required for the production of functionally mature TJs and also the localization of ezrin to the plasma membrane. Finally, we demonstrate that reduced CRB3b expression in head and neck squamous cell carcinoma (HNSCC) correlates with cytoplasmic ezrin, a biomarker for aggressive disease, and shows evidence that while CRB3a expression has no effect, low CRB3b and high cytoplasmic ezrin expression combined may be prognostic for HNSCC.
AB - Crumbs 3 (CRB3) is a component of epithelial junctions, which has been implicated in apical-basal polarity, apical identity, apical stability, cell adhesion, and cell growth. CRB3 undergoes alternative splicing to yield two variants: CRB3a and CRB3b. Here, we describe novel data demonstrating that, as with previous studies on CRB3a, CRB3b also promotes the formation of tight junctions (TJs). However, significantly we demonstrate that the 4.1-ezrin-radixin-moesin-binding motif of CRB3b is required for CRB3b functionality and that ezrin binds to the FBM of CRB3b. Furthermore, we show that ezrin contributes to CRB3b functionality and the correct distribution of TJ proteins. We demonstrate that both CRB3 isoforms are required for the production of functionally mature TJs and also the localization of ezrin to the plasma membrane. Finally, we demonstrate that reduced CRB3b expression in head and neck squamous cell carcinoma (HNSCC) correlates with cytoplasmic ezrin, a biomarker for aggressive disease, and shows evidence that while CRB3a expression has no effect, low CRB3b and high cytoplasmic ezrin expression combined may be prognostic for HNSCC.
KW - CRB3
KW - crumbs
KW - FERM proteins
KW - FBM
KW - tight junctions
KW - ezrin
U2 - 10.1093/jmcb/mjw020
DO - 10.1093/jmcb/mjw020
M3 - Article
C2 - 27190314
SN - 1674-2788
VL - 8
SP - 439
EP - 455
JO - Journal of Molecular Cell Biology
JF - Journal of Molecular Cell Biology
IS - 5
ER -