Caveolin-1 influences P2X7 receptor expression and localization in mouse lung alveolar epithelial cells.
The P2X7 receptor has recently been described as a marker for lung alveolar epithelial type I cells. Here, we demonstrate both the expression of P2X7 protein and its partition into lipid rafts in the mouse lung alveolar epithelial cell line E10. A significant degree of colocalization was observed between P2X7 and the raft marker protein Caveolin-1; also, P2X7 protein was associated with caveolae. A marked reduction in P2X7 immunoreactivity was observed in lung sections prepared from Caveolin-1-knockout mice, indicating that Caveolin-1 expression was required for full expression of P2X7 protein. Indeed, suppression of Caveolin-1 protein expression in E10 cells using short hairpin RNAs resulted in a large reduction in P2X7 protein expression. Our data demonstrate a potential interaction between P2X7 protein and Caveolin-1 in lipid rafts, and provide a basis for further functional and biochemical studies to probe the physiologic significance of this interaction.
Barth
K
K
Institute of Anatomy, Medical Faculty Carl Gustav Carus, Dresden University of Technology, Germany.
Weinhold
K
K
Guenther
A
A
Young
M T
MT
Schnittler
H
H
Kasper
M
M
D000818:Animals; D051242:Caveolin 1 / Q000378:metabolism*; D002460:Cell Line; D020285:Cryoelectron Microscopy; D004847:Epithelial Cells / Q000378:metabolism*; D008168:Lung / Q000166:cytology / Q000378:metabolism; D021962:Membrane Microdomains / Q000378:metabolism* / Q000648:ultrastructure; D051379:Mice; D011650:Pulmonary Alveoli / Q000166:cytology / Q000378:metabolism*; D018048:Receptors, Purinergic P2 / Q000378:metabolism*; D058486:Receptors, Purinergic P2X7; D020545:Respiratory Mucosa / Q000166:cytology / Q000378:metabolism*
D051242:Caveolin 1; C546469:P2rx7 protein, mouse; D018048:Receptors, Purinergic P2; D058486:Receptors, Purinergic P2X7