PKCι interacts with Rab14 and modulates epithelial barrier function through regulation of claudin-2 levels
| Autor: | Edward K. Mandell, Sourav Ghosh, Ruifeng Lu, Dogukan Dalgalan, Jean M. Wilson, Sara S. Parker |
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| Jazyk: | angličtina |
| Rok vydání: | 2015 |
| Předmět: |
endocrine system diseases
Biology Occludin urologic and male genital diseases Permeability Madin Darby Canine Kidney Cells Tight Junctions Dogs Animals Humans Small GTPase Claudin-2 Claudin Molecular Biology Protein Kinase C Epithelial polarity Gene knockdown Tight junction Epithelial Cells Cell Biology Articles digestive system diseases Cell biology Transport protein Isoenzymes Protein Transport Gene Expression Regulation Membrane Trafficking rab GTP-Binding Proteins Paracellular transport Gene Knockdown Techniques Lysosomes |
| Zdroj: | Molecular Biology of the Cell |
| ISSN: | 1939-4586 1059-1524 |
| Popis: | PKCι has an essential role in epithelial polarity. Its knockdown increases epithelial barrier through control of the trafficking of claudin-2. PKCι interacts directly with the small GTPase Rab14, and these proteins colocalize in cells. It is proposed that these proteins act together to regulate claudin-2 trafficking. PKCι is essential for the establishment of epithelial polarity and the normal assembly of tight junctions. We find that PKCι knockdown does not compromise the steady-state distribution of most tight junction proteins but results in increased transepithelial resistance (TER) and decreased paracellular permeability. Analysis of the levels of tight junction components demonstrates that claudin-2 protein levels are decreased. However, other tight junction proteins, such as claudin-1, ZO-1, and occludin, are unchanged. Incubation with an aPKC pseudosubstrate recapitulates the phenotype of PKCι knockdown, including increased TER and decreased levels of claudin-2. In addition, overexpression of PKCι results in increased claudin-2 levels. ELISA and coimmunoprecipitation show that the TGN/endosomal small GTPase Rab14 and PKCι interact directly. Immunolabeling shows that PKCι and Rab14 colocalize in both intracellular puncta and at the plasma membrane and that Rab14 expression is required for normal PKCι distribution in cysts in 3D culture. We showed previously that knockdown of Rab14 results in increased TER and decreased claudin-2. Our results suggest that Rab14 and aPKC interact to regulate trafficking of claudin-2 out of the lysosome-directed pathway. |
| Databáze: | OpenAIRE |
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