Format

Send to

Choose Destination
See comment in PubMed Commons below
BMC Nephrol. 2013 Feb 11;14:34. doi: 10.1186/1471-2369-14-34.

Intracellular calcium release modulates polycystin-2 trafficking.

Author information

1
Department of Medical Biochemistry and Biophysics, Karolinska Institutet, SE-171 77, Stockholm, Sweden.

Abstract

BACKGROUND:

Polycystin-2 (PC2), encoded by the gene that is mutated in autosomal dominant polycystic kidney disease (ADPKD), functions as a calcium (Ca(2+)) permeable ion channel. Considerable controversy remains regarding the subcellular localization and signaling function of PC2 in kidney cells.

METHODS:

We investigated the subcellular PC2 localization by immunocytochemistry and confocal microscopy in primary cultures of human and rat proximal tubule cells after stimulating cytosolic Ca(2+) signaling. Plasma membrane (PM) Ca(2+) permeability was evaluated by Fura-2 manganese quenching using time-lapse fluorescence microscopy.

RESULTS:

We demonstrated that PC2 exhibits a dynamic subcellular localization pattern. In unstimulated human or rat proximal tubule cells, PC2 exhibited a cytosolic/reticular distribution. Treatments with agents that in various ways affect the Ca(2+) signaling machinery, those being ATP, bradykinin, ionomycin, CPA or thapsigargin, resulted in increased PC2 immunostaining in the PM. Exposing cells to the steroid hormone ouabain, known to trigger Ca(2+) oscillations in kidney cells, caused increased PC2 in the PM and increased PM Ca(2+) permeability. Intracellular Ca(2+) buffering with BAPTA, inositol 1,4,5-trisphosphate receptor (InsP3R) inhibition with 2-aminoethoxydiphenyl borate (2-APB) or Ca(2+)/Calmodulin-dependent kinase inhibition with KN-93 completely abolished ouabain-stimulated PC2 translocation to the PM.

CONCLUSIONS:

These novel findings demonstrate intracellular Ca(2+)-dependent PC2 trafficking in human and rat kidney cells, which may provide new insight into cyst formations in ADPKD.

PMID:
23398808
PMCID:
PMC3577431
DOI:
10.1186/1471-2369-14-34
[Indexed for MEDLINE]
Free PMC Article
PubMed Commons home

PubMed Commons

0 comments
How to join PubMed Commons

    Supplemental Content

    Full text links

    Icon for BioMed Central Icon for PubMed Central
    Loading ...
    Support Center