This proposal seeks to characterize the membrane components involved in the hepatocyte anion transport system, and to elucidate their disposition within the membrane system with the ultimate goal of understanding the architecture, dynamics and regulation of transport channels. Studies using hepatocytes derived from resting and regenerating liver, and hepatoma tissue culture (HTC) cells will be concerned with the analysis of anion transport properties and the identification, isolation and characterization of the membrane associated anion transport proteins using photoaffinity labeling in conjunction wwth differential extraction and chromatographic techniques. The purified proteins will be characterized by amino acid and carbohydrate analysis as well as by tryptic fingerprint mapping. The functional role of these components in the transport process will be evaluated using liposome reconstitution procedures. The proteoliposome system will be evaluated by characterizing sulfate transport properties and the effects of anion transport inhibitors. The structural organization and spacial orientation of the transport components in the hepatocyte and proteoliposome systems will be characterized using a variety of photoaffinity probes in conjunction with proteolytic dissection. The effect of proteolysis of the membrane assocated transport proteins on the transport function of the cells and liposomes will also be evaluated. These studies should provide many insights into the mechanism of hepatocyte anion transport and contribute to our general understanding of transmembrane transport channels.

Agency
National Institute of Health (NIH)
Institute
National Institute of Arthritis, Diabetes, Digestive and Kidney Diseases (NIADDK)
Type
Research Project (R01)
Project #
5R01AM025836-07
Application #
3151558
Study Section
Cellular Biology and Physiology Subcommittee 1 (CBY)
Project Start
1979-08-01
Project End
1987-07-31
Budget Start
1985-08-01
Budget End
1986-07-31
Support Year
7
Fiscal Year
1985
Total Cost
Indirect Cost
Name
University of Southern California
Department
Type
Schools of Medicine
DUNS #
041544081
City
Los Angeles
State
CA
Country
United States
Zip Code
90033