The SARS coronavirus E protein interacts with PALS1 and alters tight junction formation and epithelial morphogenesis

• Published in: Molecular biology of the cell 2010-11, Vol.21 (22), p.3838-3852
• Main Authors: Teoh, Kim-Tat, Siu, Yu-Lam, Chan, Wing-Lim, Schlüter, Marc A, Liu, Chia-Jen, Peiris, J S Malik, Bruzzone, Roberto, Margolis, Benjamin, Nal, Béatrice
• Format: Article
• Language: English
• Subjects: Animals; Binding Sites; Cell Line; Cercopithecus aethiops; Epithelial Cells - cytology; Epithelial Cells - metabolism; Epithelial Cells - virology; Epithelium - growth & development; Epithelium - metabolism; Glutathione Transferase; HEK293 Cells; Host-Pathogen Interactions; Humans; Immunoblotting; Life Sciences; Luminescent Proteins - genetics; Luminescent Proteins - metabolism; Membrane Proteins - genetics; Membrane Proteins - metabolism; Microbiology and Parasitology; Microscopy, Fluorescence; Morphogenesis; Nucleoside-Phosphate Kinase - genetics; Nucleoside-Phosphate Kinase - metabolism; Protein Binding; Recombinant Fusion Proteins - genetics; Recombinant Fusion Proteins - metabolism; SARS coronavirus; SARS Virus - metabolism; SARS Virus - physiology; Tight Junctions - metabolism; Tight Junctions - virology; Two-Hybrid System Techniques; Vero Cells; Viral Envelope Proteins - genetics; Viral Envelope Proteins - metabolism; Virology
• ISSN: 1059-1524; 1939-4586
• DOI: 10.1091/mbc.E10-04-0338

Intercellular tight junctions define epithelial apicobasal polarity and form a physical fence which protects underlying tissues from pathogen invasions. PALS1, a tight junction-associated protein, is a member of the CRUMBS3-PALS1-PATJ polarity complex, which is crucial for the establishment and maintenance of epithelial polarity in mammals. Here we report that the carboxy-terminal domain of the SARS-CoV E small envelope protein (E) binds to human PALS1. Using coimmunoprecipitation and pull-down assays, we show that E interacts with PALS1 in mammalian cells and further demonstrate that the last four carboxy-terminal amino acids of E form a novel PDZ-binding motif that binds to PALS1 PDZ domain. PALS1 redistributes to the ERGIC/Golgi region, where E accumulates, in SARS-CoV-infected Vero E6 cells. Ectopic expression of E in MDCKII epithelial cells significantly alters cyst morphogenesis and, furthermore, delays formation of tight junctions, affects polarity, and modifies the subcellular distribution of PALS1, in a PDZ-binding motif-dependent manner. We speculate that hijacking of PALS1 by SARS-CoV E plays a determinant role in the disruption of the lung epithelium in SARS patients.