The long-term goal of this research is to characterize two membrane transport systems involved in the regulation of intracellular pH in an established line of kidney epithelial cells (LLC-PK1): the amiloride-sensitive Na/H exchanger and the DIDS-sensitive Cl/HCO3 exchanger. Mutants defective in each of these transport systems have already been isolated, and will be characterized by isotope flux studies and by optical measurements of pH, both at the whole-cell level and in isolated membrane vesicles. The mutants will be used in physiological studies to investigate the relative roles of the Na/H and Cl/HCO3 exchangers in controlling pH during growth and differentiation. They will also be used to identify the transport proteins and to clone the corresponding genes. The proposed studies should contribute to our understanding of the physiology and pathophysiology of the proximal tubule and other leaky epithelia. They should also shed light on such fundamental processes as the regulation of intracellular pH and the control of cell proliferation.

Agency
National Institute of Health (NIH)
Institute
National Institute of General Medical Sciences (NIGMS)
Type
Research Project (R01)
Project #
5R01GM037279-02
Application #
3292555
Study Section
Cellular Biology and Physiology Subcommittee 1 (CBY)
Project Start
1986-07-01
Project End
1991-06-30
Budget Start
1987-07-01
Budget End
1988-06-30
Support Year
2
Fiscal Year
1987
Total Cost
Indirect Cost
Name
Yale University
Department
Type
Schools of Medicine
DUNS #
082359691
City
New Haven
State
CT
Country
United States
Zip Code
06520
Reilly, R F; Hildebrandt, F; Biemesderfer, D et al. (1991) cDNA cloning and immunolocalization of a Na(+)-H+ exchanger in LLC-PK1 renal epithelial cells. Am J Physiol 261:F1088-94
Igarashi, P; Reilly, R F; Hildebrandt, F et al. (1991) Molecular biology of renal Na(+)-H+ exchangers. Kidney Int Suppl 33:S84-9
Reilly, R F; Haggerty, J G; Aronson, P S et al. (1991) Increased Na(+)-H+ antiporter activity in apical membrane vesicles from mutant LLC-PK1 cells. Am J Physiol 260:C738-44
Huot, S J; Cassel, D; Igarashi, P et al. (1989) Identification and purification of a renal amiloride-binding protein with properties of the Na+-H+ exchanger. J Biol Chem 264:683-6
Haggerty, J G; Agarwal, N; Reilly, R F et al. (1988) Pharmacologically different Na/H antiporters on the apical and basolateral surfaces of cultured porcine kidney cells (LLC-PK1). Proc Natl Acad Sci U S A 85:6797-801
Haggerty, J G; Agarwal, N; Cragoe Jr, E J et al. (1988) LLC-PK1 mutant with increased Na+-H+ exchange and decreased sensitivity to amiloride. Am J Physiol 255:C495-501