The Hypertonic Environment Differentially Regulates Wild-type CFTR and TNR-CFTR Chloride Channels

Cellular Physiology and Biochemistry

关键词: CFTR;    TNR-CFTR;    Sodium chloride;    Urea;    Sucrose;    MDCK cells;    Hypertonic environment;    Plasma membrane;   

DOI  :  10.1159/000322325

学科分类：分子生物学，细胞生物学和基因

来源: S Karger AG

【 摘 要 】

This study tested the hypotheses that the hypertonic environment of the renal medulla regulates the expression of cystic fibrosis transmembrane conductance regulator protein (CFTR) and its natural splice variant, TNR-CFTR. To accomplish this, Madin-Darby canine kidney (MDCK) stable cell lines expressing TNR-CFTR or CFTR were used. The cells were treated with hypertonic medium made with either NaCl or urea or sucrose (480 mOsm/kg or 560 mOsm/kg) to mimic the tonicity of the renal medulla environment. Western blot data showed that CFTR and TNR-CFTR total cell protein is increased by hypertonic medium, but using the surface biotinylation technique, only CFTR was found to be increased in cell plasma membrane. Confocal microscopy showed TNR-CFTR localization primarily at the endoplasmic reticulum and plasma membrane. In conclusion, CFTR and TNR-CFTR have different patterns of distribution in MDCK cells and they are modulated by a hypertonic environment, suggesting their physiological importance in renal medulla.

【 授权许可】

CC BY-NC-ND