Intracellular calcium release modulates polycystin-2 trafficking

BMC Nephrology

Research Article

Cristián Ibarra¹  Seth Malmersjö¹  Per Uhlén¹  Ayako Miyakawa²  Peter Wiklund³  Anita Aperia⁴ 

[1] Department of Medical Biochemistry and Biophysics, Karolinska Institutet, SE-171 77, Stockholm, Sweden;Department of Medical Biochemistry and Biophysics, Karolinska Institutet, SE-171 77, Stockholm, Sweden;Department of Molecular Medicine and Surgery, Karolinska University Hospital, SE-171 76, Stockholm, Sweden;Department of Molecular Medicine and Surgery, Karolinska University Hospital, SE-171 76, Stockholm, Sweden;Department of Woman and Child Health, Astrid Lindgren Children’s Hospital Q2:09, Karolinska University Hospital, SE-171 76, Stockholm, Sweden;

关键词: Polycystin-2;    Protein trafficking;    Calcium signaling;    Kidney cells;    Autosomal dominant polycystic kidney disease;   

DOI  :  10.1186/1471-2369-14-34

 received in 2012-09-06, accepted in 2013-02-06,  发布年份 2013

来源: Springer

【 摘 要 】

BackgroundPolycystin-2 (PC2), encoded by the gene that is mutated in autosomal dominant polycystic kidney disease (ADPKD), functions as a calcium (Ca2+) permeable ion channel. Considerable controversy remains regarding the subcellular localization and signaling function of PC2 in kidney cells.MethodsWe investigated the subcellular PC2 localization by immunocytochemistry and confocal microscopy in primary cultures of human and rat proximal tubule cells after stimulating cytosolic Ca2+ signaling. Plasma membrane (PM) Ca2+ permeability was evaluated by Fura-2 manganese quenching using time-lapse fluorescence microscopy.ResultsWe 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 Ca2+ 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 Ca2+ oscillations in kidney cells, caused increased PC2 in the PM and increased PM Ca2+ permeability. Intracellular Ca2+ buffering with BAPTA, inositol 1,4,5-trisphosphate receptor (InsP3R) inhibition with 2-aminoethoxydiphenyl borate (2-APB) or Ca2+/Calmodulin-dependent kinase inhibition with KN-93 completely abolished ouabain-stimulated PC2 translocation to the PM.ConclusionsThese novel findings demonstrate intracellular Ca2+-dependent PC2 trafficking in human and rat kidney cells, which may provide new insight into cyst formations in ADPKD.

【 授权许可】

Unknown   
© Miyakawa et al.; licensee BioMed Central Ltd. 2013. This article is published under license to BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.