Tissue distribution and subcellular localization of the ClC-5 chloride channel in rat intestinal cells.
ClC-5 is the Cl- channel that is mutated in Dent's disease, an X-chromosome-linked disease characterized by low molecular weight proteinuria, hypercalciuria, and kidney stones. It is predominantly expressed in endocytically active renal proximal cells. We investigated whether this Cl- channel could also be expressed in intestinal tissues that have endocytotic machinery. ClC-5 mRNA was detected in the rat duodenum, jejunum, ileum, and colon. Western blot analyses revealed the presence of the 83-kDa ClC-5 protein in these tissues. Indirect immunofluorescence studies showed that ClC-5 was mainly concentrated in the cytoplasm above the nuclei of enterocytes and colon cells. ClC-5 partially colocalized with the transcytosed polymeric immunoglobulin receptor but was not detectable together with the brush-border-anchored sucrase isomaltase. A subfractionation of vesicles obtained by differential centrifugation showed that ClC-5 is associated with the vacuolar 70-kDa H+-ATPase and the small GTPases rab4 and rab5a, two markers of early endosomes. Thus these results indicate that ClC-5 is present in the small intestine and colon of rats and suggest that it plays a role in the endocytotic pathways of intestinal cells.
Vandewalle
A
A
Institut National de la Santé et de la Recherche Médicale, Unité 478, Institut Fédératif de Recherche 02, Faculté de Médecine Xavier Bichat, BP 416, 75870 Paris Cedex 18, France. vandewal@bichat.inserm.fr
Cluzeaud
F
F
Peng
K C
KC
Bens
M
M
Lüchow
A
A
Günther
W
W
Jentsch
T J
TJ
D000818:Animals; D018118:Chloride Channels / Q000378:metabolism*; D003106:Colon / Q000378:metabolism*; D004847:Epithelial Cells / Q000378:metabolism*; D007421:Intestine, Small / Q000378:metabolism*; D007668:Kidney / Q000378:metabolism*; D008297:Male; D012333:RNA, Messenger / Q000378:metabolism; D051381:Rats; D013347:Subcellular Fractions / Q000378:metabolism; D014018:Tissue Distribution / Q000502:physiology
C097503:CLC-5 chloride channel; D018118:Chloride Channels; D012333:RNA, Messenger