Clathrin is a key regulator of basolateral polarity.
Clathrin-coated vesicles are vehicles for intracellular trafficking in all nucleated cells, from yeasts to humans. Many studies have demonstrated their essential roles in endocytosis and cellular signalling processes at the plasma membrane. By contrast, very few of their non-endocytic trafficking roles are known, the best characterized being the transport of hydrolases from the Golgi complex to the lysosome. Here we show that clathrin is required for polarity of the basolateral plasma membrane proteins in the epithelial cell line MDCK. Clathrin knockdown depolarized most basolateral proteins, by interfering with their biosynthetic delivery and recycling, but did not affect the polarity of apical proteins. Quantitative live imaging showed that chronic and acute clathrin knockdown selectively slowed down the exit of basolateral proteins from the Golgi complex, and promoted their mis-sorting into apical carrier vesicles. Our results demonstrate a broad requirement for clathrin in basolateral protein trafficking in epithelial cells.
Deborde
Sylvie
S
Department of Ophthalmology, Dyson Vision Research Institute, LC-300, Weill Medical College of Cornell University, 1300 York Avenue, New York, New York 10065, USA.
Perret
Emilie
E
Gravotta
Diego
D
Deora
Ami
A
Salvarezza
Susana
S
Schreiner
Ryan
R
Rodriguez-Boulan
Enrique
E
D000818:Animals; D002402:Cathepsin D / Q000378:metabolism; D002460:Cell Line; D016764:Cell Polarity; D002966:Clathrin / Q000172:deficiency / Q000235:genetics / Q000378:metabolism*; D033922:Clathrin Heavy Chains / Q000235:genetics / Q000378:metabolism; D004285:Dogs; D004847:Epithelial Cells / Q000166:cytology* / Q000378:metabolism; D006056:Golgi Apparatus / Q000378:metabolism; D006801:Humans; D007444:Inulin / Q000378:metabolism; D008247:Lysosomes / Q000378:metabolism; D021381:Protein Transport; D011973:Receptors, LDL / Q000378:metabolism; D011990:Receptors, Transferrin / Q000378:metabolism; D019108:Tight Junctions / Q000378:metabolism; D013997:Time Factors; D021601:trans-Golgi Network / Q000378:metabolism
D002966:Clathrin; D011973:Receptors, LDL; D011990:Receptors, Transferrin; D033922:Clathrin Heavy Chains; D007444:Inulin; D002402:Cathepsin D