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Mammalian Lgl Forms a Protein Complex with PAR-6 and aPKC Independently of PAR-3 to Regulate Epithelial Cell Polarity
- Source :
- Current Biology. 13:734-743
- Publication Year :
- 2003
- Publisher :
- Elsevier BV, 2003.
-
Abstract
- Background : Epithelial cells have apicobasal polarity and an asymmetric junctional complex that provides the bases for development and tissue maintenance. In both vertebrates and invertebrates, the evolutionarily conserved protein complex, PAR-6/aPKC/PAR-3, localizes to the subapical region and plays critical roles in the establishment of a junctional complex and cell polarity. In Drosophila , another set of proteins called tumor suppressors, such as Lgl, which localize separately to the basolateral membrane domain but genetically interact with the subapical proteins, also contribute to the establishment of cell polarity. However, how physically separated proteins interact remains to be clarified. Results : We show that mammalian Lgl competes for PAR-3 in forming an independent complex with PAR-6/aPKC. During cell polarization, mLgl initially colocalizes with PAR-6/aPKC at the cell-cell contact region and is phosphorylated by aPKC, followed by segregation from apical PAR-6/aPKC to the basolateral membrane after cells are polarized. Overexpression studies establish that increased amounts of the mLgl/PAR-6/aPKC complex suppress the formation of epithelial junctions; this contrasts with the previous observation that the complex containing PAR-3 promotes it. Conclusions : These results indicate that PAR-6/aPKC selectively interacts with either mLgl or PAR-3 under the control of aPKC activity to regulate epithelial cell polarity.
- Subjects :
- Adenoviridae Infections
Blotting, Western
Biology
Cell junction
Antibodies
General Biochemistry, Genetics and Molecular Biology
law.invention
law
Cell polarity
Animals
Humans
Protein Kinase C
Epithelial polarity
Homeodomain Proteins
Polarity (international relations)
Agricultural and Biological Sciences(all)
Biochemistry, Genetics and Molecular Biology(all)
Gene Expression Profiling
Tumor Suppressor Proteins
Cell Polarity
Proteins
Contact region
A protein
Epithelial Cells
Precipitin Tests
Clone Cells
Cell biology
Cytoskeletal Proteins
Microscopy, Fluorescence
Phosphorylation
Suppressor
Biological Assay
Electrophoresis, Polyacrylamide Gel
General Agricultural and Biological Sciences
Sequence Alignment
Subjects
Details
- ISSN :
- 09609822
- Volume :
- 13
- Database :
- OpenAIRE
- Journal :
- Current Biology
- Accession number :
- edsair.doi.dedup.....531c7e30e3727a896439dae1a4d22dec