Phosphatidylinositol phosphate-dependent regulation of Xenopus ENaC by MARCKS protein.


Phosphatidylinositol phosphates (PIPs) are known to regulate epithelial sodium channels (ENaC). Lipid binding assays and coimmunoprecipitation showed that the amino-terminal domain of the β- and γ-subunits of Xenopus ENaC can directly bind to phosphatidylinositol 4,5-bisphosphate (PIP(2)), phosphatidylinositol 3,4,5-trisphosphate (PIP(3)), and phosphatidic acid (PA). Similar assays demonstrated various PIPs can bind strongly to a native myristoylated alanine-rich C-kinase substrate (MARCKS), but weakly or not at all to a mutant form of MARCKS. Confocal microscopy demonstrated colocalization between MARCKS and PIP(2). Confocal microscopy also showed that MARCKS redistributes from the apical membrane to the cytoplasm after PMA-induced MARCKS phosphorylation or ionomycin-induced intracellular calcium increases. Fluorescence resonance energy transfer studies revealed ENaC and MARCKS in close proximity in 2F3 cells when PKC activity and intracellular calcium concentrations are low. Transepithelial current measurements from Xenopus 2F3 cells treated with PMA and single-channel patch-clamp studies of Xenopus 2F3 cells treated with a PKC inhibitor altered Xenopus ENaC activity, which suggest an essential role for MARCKS in the regulation of Xenopus ENaC activity.

DOI: 10.1152/ajprenal.00703.2011
Citations per Year

375 Citations

Semantic Scholar estimates that this publication has 375 citations based on the available data.

See our FAQ for additional information.

Cite this paper

@article{Alli2012PhosphatidylinositolPR, title={Phosphatidylinositol phosphate-dependent regulation of Xenopus ENaC by MARCKS protein.}, author={Abdel A Alli and Hui-Fang Bao and Alia A Alli and Yasir Aldrugh and John Z Song and He-ping Ma and Ling Yu and Otor K Al-Khalili and Douglas C. Eaton}, journal={American journal of physiology. Renal physiology}, year={2012}, volume={303 6}, pages={F800-11} }