Autosomal dominant polycystic kidney disease (PKD) is caused by mutation of polycystin-1 or polycystin-2. Polycystin-2 is a Ca2+-permeable cation channel. Polycystin-1 is an integral membrane protein of less defined function. The N-terminal extracellular region of polycystin-1 contains potential motifs for protein and carbohydrate interaction. We now report that expression of polycystin-1 alone in Chinese hamster ovary (CHO) cells and in PKD2-null cells can confer Ca2+-permeable non-selective cation currents. Co-expression of a loss-of-function mutant of polycystin-2 in CHO cells does not reduce polycystin-1-dependent channel activity. A polycystin-1 mutant lacking ∼2900 amino acids of the extracellular region is targeted to the cell surface but does not produce current. Extracellular application of antibodies against the immunoglobulin-like PKD domains reduces polycystin-1-dependent current. These results support the hypothesis that polycystin-1 is a surface membrane receptor that transduces the signal via changes in ionic currents.
|Original language||English (US)|
|Number of pages||8|
|Journal||Journal of Biological Chemistry|
|State||Published - Jun 11 2004|
ASJC Scopus subject areas
- Molecular Biology
- Cell Biology