Effect of acidification on the location of H+-ATPase in cultured inner medullary collecting duct cells.

In previous studies, our laboratory has utilized a cell line derived from the rat inner medullary collecting duct (IMCD) as a model system for mammalian renal epithelial cell acid secretion. We have provided evidence, from a physiological perspective, that acute cellular acidification stimulates apical exocytosis and elicits a rapid increase in proton secretion that is mediated by an H+-ATPase. The purpose of these experiments was to examine the effect of acute cellular acidification on the distribution of the vacuolar H+-ATPase in IMCD cells in vitro. We utilized the 31-kDa subunit of the H+-ATPase as a marker of the complete enzyme. The distribution of this subunit of the H+-ATPase was evaluated by immunohistochemical techniques (confocal and electron microscopy), and we found that there is a redistribution of these pumps from vesicles to the apical membrane. Immunoblot evaluation of isolated apical membrane revealed a 237 ± 34% ( P < 0.05, n = 9) increase in the 31-kDa subunit present in the membrane fraction 20 min after the induction of cellular acidification. Thus our results demonstrate the presence of this pump subunit in the IMCD cell line in vitro and that cell acidification regulates the shuttling of cytosolic vesicles containing the 31-kDa subunit into the apical membrane.

[1]  H. Yuan,et al.  Characterization of anion exchangers in an inner medullary collecting duct cell line. , 1998, Journal of the American Society of Nephrology : JASN.

[2]  E. Alexander,et al.  H+ secretion is inhibited by clostridial toxins in an inner medullary collecting duct cell line. , 1997, American journal of physiology. Renal physiology.

[3]  S. Alper,et al.  Regulation of AE1 anion exchanger and H(+)-ATPase in rat cortex by acute metabolic acidosis and alkalosis. , 1997, Kidney international.

[4]  R. Scheller,et al.  Synaptic vesicle biogenesis, docking, and fusion: a molecular description. , 1996, Physiological reviews.

[5]  G. Augustine,et al.  Exocytosis: proteins and perturbations. , 1996, Annual review of pharmacology and toxicology.

[6]  D. Underhill,et al.  Physiology and biochemistry of the kidney vacuolar H+-ATPase. , 1996, Annual review of physiology.

[7]  J. Stow,et al.  Protein trafficking and polarity in kidney epithelium: from cell biology to physiology. , 1996, Physiological reviews.

[8]  S. Masino,et al.  Intracellular modulation of acid secretion in rat inner medullary collecting duct cells. , 1994, The American journal of physiology.

[9]  T. Kreis,et al.  Involvement of β-COP in membrane traffic through the Golgi complex , 1991 .

[10]  P. Hemken,et al.  Expression and distribution of renal vacuolar proton-translocating adenosine triphosphatase in response to chronic acid and alkali loads in the rat. , 1991, The Journal of clinical investigation.

[11]  S. Borkan,et al.  Transient ischemia or heat stress induces a cytoprotectant protein in rat kidney. , 1991, The American journal of physiology.

[12]  E. Alexander,et al.  Na(+)-H+ exchange is stimulated by protein kinase C activation in inner medullary collecting duct cells. , 1990, The American journal of physiology.

[13]  R. Schwimmer,et al.  Polarized insertion of an intracellular glycoprotein pool into the apical membrane of MDCK cells. , 1990, The American journal of physiology.

[14]  D. Brown,et al.  Localization of a proton-pumping ATPase in rat kidney. , 1988, The Journal of clinical investigation.

[15]  J. Verlander,et al.  Relationship between structure and function in distal tubule and collecting duct. , 1988, Journal of electron microscopy technique.

[16]  H. Bengele,et al.  Mechanisms of H+ secretion by inner medullary collecting duct cells. , 1988, The American journal of physiology.

[17]  G. Schwartz,et al.  Carbon dioxide causes exocytosis of vesicles containing H+ pumps in isolated perfused proximal and collecting tubules. , 1985, The Journal of clinical investigation.

[18]  P. R. Steinmetz,et al.  Role of membrane fusion in CO2 stimulation of proton secretion by turtle bladder. , 1983, The American journal of physiology.

[19]  Q. Al-Awqati,et al.  Exocytosis regulates urinary acidification in turtle bladder by rapid insertion of H+ pumps into the luminal membrane. , 1982, Proceedings of the National Academy of Sciences of the United States of America.

[20]  R. Scott,et al.  Plasma membrane vesiculation in 3T3 and SV3T3 cells. I. Morphological and biochemical characterization. , 1979, Journal of cell science.

[21]  R. Scott,et al.  Plasma membrane vesiculation in 3T3 and SV3T3 cells. II. Factors affecting the process of vesiculation. , 1979, Journal of cell science.