Abstract

In normal airway epithelial cells, chloride channels can be activated by agents which raise intracellular c-AMP. CF airway epithelial cells have been shown to contain chloride channels which cannot be activated by a normal increase in intracellular c-AMP. The defect in CF may involve some step in an activation sequence distal to the generation of c-AMP. Alternatively, CF cells could cause Cl-channel activity to be tonically inhibited. We propose to isolate and identify substances in the cytosol or associated with cell membranes which control the activity of single chloride channels in CF and non-CF airway epithelial cells.
The specific aims of this proposal are: (1) Assay cytoplasm and membrane fractions derived from CF and non-CF cells for the ability to activate or deactivate chloride channels in the apical cell membrane of CF and non-CF cells and compare these effects to the effects of purified protein kinases or phosphatases. (2) Identify and isolate c-AMP dependent protein kinase activity, phosphatase activity, and phosphoproteins in cytoplasm and membrane fractions derived from CF and non-CF cells and assay for ability to alter ion channel function. The results from the proposed experiments should reveal if CF cells produce an inhibitor of ion channel activation, or if CF cells are missing a portion of the normal activation sequence of Cl channels found in normal cells.

  Funding Agency

Agency
National Institute of Health (NIH)
Institute
National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)
Type
Research Project (R01)
Project #
5R01DK039615-03
Application #
3239436
Study Section
Diabetes, Endocrinology and Metabolic Diseases B Subcommittee (DDK)
Project Start
1988-03-01
Project End
1991-02-28
Budget Start
1990-03-01
Budget End
1991-02-28
Support Year
3
Fiscal Year
1990
Total Cost
Indirect Cost

  Institution

Name
University of North Carolina Chapel Hill
Department
Type
Schools of Medicine
DUNS #
078861598
City
Chapel Hill
State
NC
Country
United States
Zip Code
27599

  Publications

Patel, Niketa A; Kaneko, Satoshi; Apostolatos, Hercules S et al. (2005) Molecular and genetic studies imply Akt-mediated signaling promotes protein kinase CbetaII alternative splicing via phosphorylation of serine/arginine-rich splicing factor SRp40. J Biol Chem 280:14302-9
Bae, Sun Sik; Cho, Han; Mu, James et al. (2003) Isoform-specific regulation of insulin-dependent glucose uptake by Akt/protein kinase B. J Biol Chem 278:49530-6
Whiteman, Eileen L; Chen, Janine J; Birnbaum, Morris J (2003) Platelet-derived growth factor (PDGF) stimulates glucose transport in 3T3-L1 adipocytes overexpressing PDGF receptor by a pathway independent of insulin receptor substrates. Endocrinology 144:3811-20
Lawrence, J T; Birnbaum, M J (2001) ADP-ribosylation factor 6 delineates separate pathways used by endothelin 1 and insulin for stimulating glucose uptake in 3T3-L1 adipocytes. Mol Cell Biol 21:5276-85
Garza, L A; Birnbaum, M J (2000) Insulin-responsive aminopeptidase trafficking in 3T3-L1 adipocytes. J Biol Chem 275:2560-7
Hausdorff, S F; Fingar, D C; Morioka, K et al. (1999) Identification of wortmannin-sensitive targets in 3T3-L1 adipocytes. DissociationoOf insulin-stimulated glucose uptake and glut4 translocation. J Biol Chem 274:24677-84
Summers, S A; Whiteman, E L; Cho, H et al. (1999) Differentiation-dependent suppression of platelet-derived growth factor signaling in cultured adipocytes. J Biol Chem 274:23858-67
Summers, S A; Yin, V P; Whiteman, E L et al. (1999) Signaling pathways mediating insulin-stimulated glucose transport. Ann N Y Acad Sci 892:169-86
Summers, S A; Kao, A W; Kohn, A D et al. (1999) The role of glycogen synthase kinase 3beta in insulin-stimulated glucose metabolism. J Biol Chem 274:17934-40
Summers, S A; Lipfert, L; Birnbaum, M J (1998) Polyoma middle T antigen activates the Ser/Thr kinase Akt in a PI3-kinase-dependent manner. Biochem Biophys Res Commun 246:76-81

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